WO2017099837A1

WO2017099837A1 - Downlink reachability for ultra low power saving devices using d2d

Info

Publication number: WO2017099837A1
Application number: PCT/US2016/028786
Authority: WO
Inventors: Sangeetha L. Bangolae; Kyeongin Jeong; Youn Hyoung Heo; Richard C. Burbidge; Mo-Han Fong
Original assignee: Intel IP Corporation
Priority date: 2015-12-09
Filing date: 2016-04-22
Publication date: 2017-06-15
Also published as: TW201731320A; TWI738678B

Abstract

An apparatus for use in a remote UE of a ProSe network facilitates downlink reachability of the remote UE. The apparatus includes a processing circuit configured to detect a paging message from an eNodeB of the ProSe network, over an air interface between the eNodeB and the remote UE or through a relay UE of the ProSe network over a PC5 interface between the relay UE and the remote UE. The processing circuit is further configured to generate and transmit a connection request message to the relay UE, in response to receiving the paging message, to establish a direct connection between the remote UE and the relay UE. Further, the processing circuit is configured to detect downlink data from the eNodeB through the relay UE over the PC5 interface using EPS bearer of the remote UE or the relay UE, in response to providing the connection request message.

Description

DOWNLINK REACHABILITY FOR ULTRA LOW POWER SAVING DEVICES USING

D2D

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.

62/265,31 0 filed on December 9, 201 5, entitled "DOWNLINK REACHABILITY FOR ULTRA LOW POWER SAVING DEVICES USING D2D", the contents of which are herein incorporated by reference in their entirety.

FIELD

[0002] The present disclosure relates to proximity based services (ProSe) network and, in particular to an apparatus and a method for receiving downlink (DL) data for ultra-low power devices in the ProSe network.

BACKGROUND

[0003] In recent years, demand for access to fast mobile wireless data for mobile electronic devices has fueled the development of the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) communication system (hereinafter "LTE system"). Exploiting device-to-device (D2D) communication between nearby mobile devices improves spectrum utilization, overall throughput, and energy consumption, while enabling new peer-to-peer and location-based applications and services. A primary use case driving the D2D communication is in fallback public safety networks, where D2D-enabled LTE devices must function when cellular networks are not available, or fail.

[0004] Up to date, ProSe based D2D communication is primarily focused on public safety services, while general use cases, for example, wearable device support were mainly out of scope. With advanced relaying capability for the D2D devices and power optimizations, the ProSe based D2D communication can be utilized in general use cases, for example, low power wearable UE support. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Some examples of circuits, apparatuses and/or methods will be described in the following by way of example only. In this context, reference will be made to the accompanying Figures.

[0006] Fig. 1 is a simplified block diagram of a ProSe system in accordance with the current enhanced LTE device to device (D2D) ProSe work item, according to one embodiment of the disclosure.

[0007] Fig. 2 depicts downlink reachability of a remote UE in a ProSe system based on receiving a paging message from an eNodeB associated therewith over an air interface, according to one embodiment of the disclosure.

[0008] Fig. 3 depicts downlink reachability of a remote UE in a ProSe system based on receiving a paging message from an eNodeB associated therewith through a relay UE over a PC5 interface, according to one embodiment of the disclosure.

[0009] Fig. 4 illustrates a block diagram of an apparatus for use in a remote or wearable user equipment (UE) in a ProSe system, that facilitates downlink reachability based on a paging message received at the remote UE from an eNodeB, according to the various embodiments described herein.

[0010] Fig. 5 illustrates a block diagram of an apparatus for use in a relay user equipment (UE) in a ProSe system, that facilitates downlink reachability in a remote UE, according to the various embodiments described herein.

[0011] Fig. 6 illustrates a block diagram of an apparatus for use in an eNodeB in a ProSe system, that facilitates downlink reachability in a remote UE associated therewith, according to the various embodiments described herein.

[0012] Fig. 7 illustrates a flowchart of a method for a remote UE in a ProSe system comprising a relay UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. [0013] Fig. 8 illustrates a flowchart of a method for a remote UE in a ProSe system comprising a relay UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure.

[0014] Fig. 9 illustrates a flowchart of a method for a relay UE in a ProSe system comprising a remote UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure.

[0015] Fig. 1 0 illustrates a flowchart of a method for a relay UE in a ProSe system comprising a remote UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure.

[0016] Fig. 1 1 illustrates a flowchart of a method for an eNodeB in a ProSe system comprising a remote UE and a relay UE associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure.

[0017] Fig. 1 2 illustrates a flowchart of a method for an eNodeB in a ProSe system comprising a remote UE and a relay UE associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure.

[0018] Fig. 1 3 illustrates, for one embodiment, example components of a User Equipment (UE) device.

DETAILED DESCRIPTION

[0019] In one embodiment of the disclosure, an apparatus for use in a remote UE of a ProSe network comprising a relay UE and an eNodeB associated therewith is disclosed. The apparatus comprises a memory circuit configured to store a remote UE ID associated with the remote UE and a paired association ID indicating a paired association of the remote UE with the relay UE. The apparatus further comprises a processing circuit configured to receive a paging message comprising the remote UE ID of the remote UE from the eNodeB, over an air interface between the eNodeB and the remote UE, or through the relay UE over a PC5 interface between the relay UE and the remote UE. In some embodiments, the paging message informs the remote UE about an availability of a downlink (DL) data for the remote UE. The processing circuit is further configured to generate a connection request message comprising a cause value for paging, for subsequent transmission via a transmit circuit to the relay UE over a PC5 interface between the remote UE and the relay UE, in response to receiving the paging message. In some embodiments, the connection request message is configured to configure the relay UE to establish a direct connection between the remote UE and the relay UE, in order to receive the DL data through the relay UE. In addition, the processing circuit is configured to receive a downlink data signal comprising the DL data from the eNodeB through the relay UE over the PC5 interface, in response to transmitting the connection request message.

[0020] In one embodiment of the disclosure, an apparatus for use in a relay UE of a ProSe network comprising a remote UE and an eNodeB associated therewith is disclosed. The apparatus comprises a memory circuit configured to store a relay UE ID associated with the relay UE, a remote UE ID of the remote UE and a paired

association ID indicating a paired association of the relay UE with the remote UE, and a processing circuit configured to receive a connection request message comprising a cause value of paging from the remote UE, over a PC5 interface between the remote UE and the relay UE. In some embodiments, the cause value of paging indicates receipt of a paging message indicating an availability of downlink (DL) data to the remote UE, at the remote UE from the eNodeB over an air interface or through the relay UE. In some embodiments, the connection request message is configured to configure the relay UE to establish a direct connection with the remote UE in order for the remote UE to receive the DL data associated with remote UE from the eNodeB through the relay UE. The processing circuit is further configured to establish a direct connection between the relay UE and the remote UE, based on the connection request message; and receive a downlink data signal comprising the DL data from an S-gateway (S-GW) associated with the eNodeB using evolved packet system (EPS) bearers of the remote UE or the relay UE, for subsequent transmission to the remote UE over the PC5 interface, upon establishing the direct connection between the relay UE and the remote UE.

[0021] In one embodiment of the disclosure, an apparatus for use in an eNodeB of a ProSe network comprising a remote UE and a relay UE associated therewith is disclosed. The apparatus comprises a memory circuit configured to store a relay UE ID associated with the relay UE and a remote UE ID of the remote UE, and a processing circuit configured to provide a paging message associated with the remote UE received from an MME associated therewith, to a transmit circuit for subsequent transmission to the remote UE over an air interface between the eNodeB and the remote UE, or through the relay UE over a PC5 interface between the relay UE and the remote UE. In some embodiments, the paging message indicates the availability of downlink (DL) data for the remote UE. The processing circuit is further configured to receive a sidelink UE information message from the relay UE via a receive circuit, in response to providing the paging message, wherein the sidelink UE information message indicates a receipt of the paging message at the remote UE or an establishment of a direct connection between the remote UE and the relay UE or both. In addition, the processing circuit is configured to forward the DL data associated with the remote UE from an S-gateway (S- GW) associated therewith to the remote UE, using EPS bearers of the remote UE or EPS bearers of the relay UE, when the sidelink UE information message indicates an establishment of the connection between the remote UE and the relay UE.

[0022] The present disclosure will now be described with reference to the attached drawing figures, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As utilized herein, terms "component," "system," "interface," "circuit" and the like are intended to refer to a computer-related entity, hardware, software (e.g., in execution), and/or firmware. For example, a component can be a processing circuit (e.g., a microprocessing circuit, a controller, or other processing device), a process running on a processing circuit, a controller, an object, an executable, a program, a storage device, a computer, a tablet PC and/or a user equipment (e.g., mobile phone, etc.) with a processing device. By way of illustration, an application running on a server and the server can also be a component. One or more components can reside within a process, and a component can be localized on one computer and/or distributed between two or more computers. A set of elements or a set of other components can be described herein, in which the term "set" can be interpreted as "one or more."

[0023] Further, these components can execute from various computer readable storage media having various data structures stored thereon such as with a module, for example. The components can communicate via local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network, such as, the Internet, a local area network, a wide area network, or similar network with other systems via the signal).

[0024] As another example, a component can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processing circuits. The one or more processing circuits can be internal or external to the apparatus and can execute at least a part of the software or firmware application. As yet another example, a component can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processing circuits therein to execute software and/or firmware that confer(s), at least in part, the functionality of the electronic components.

[0025] Use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Furthermore, to the extent that the terms "including", "includes", "having", "has", "with", or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term

"comprising."

[0026] In the following description, a plurality of details is set forth to provide a more thorough explanation of the embodiments of the present disclosure. However, it will be apparent to one skilled in the art that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form rather than in detail in order to avoid obscuring embodiments of the present disclosure. In addition, features of the different embodiments described hereinafter may be combined with each other, unless specifically noted otherwise.

[0027] The current Enhanced LTE Device to Device ProSe work item (i.e., 3GPP TS 23.303, "Technical Specification Group Services and System Aspects; Proximity -based services (ProSe)") provides for communication between a remote UE and an eNodeB via a UE functioning as a communication relay (also referred to herein as "relay UE") between the remote UE and the eNodeB. Under the current Enhanced LTE Device to Device ProSe work item, a relay UE functions as a Layer-3 relay (i.e. an IP router), and the following functions are to be supported by the relay UE:

• Unicast relaying: Based on one-to-one direct communication between a Remote UE, that is not served directly by E-UTRAN, including support for the relaying of unicast traffic (UL and DL) between the Remote UEs and the E-UTRAN, the ProSe UE-to-Network Relay provides a generic Layer-3 forwarding function that can relay any type of IP traffic that is relevant for public safety communication.

• eMBMS relay support: One to many communication, including support for the relaying of multimedia broadcast multicast services (eMBMS) to Remote UEs served by the UE-to-network (UE-toNW) NW Relay.

• E-UTRAN Cell Global Identifier (ECGI) announcement: The announcement of the ECGI by a ProSe UE-to-NW Relay allowing remote UEs served by a ProSe UE-to-NW Relay to receive the value of the ECGI of the cell serving the ProSe UE-to-NW Relay.

[0028] Fig. 1 is a simplified block diagram of a ProSe system 100 in accordance with the current enhanced LTE device to device ProSe work item, according to one embodiment of the disclosure. The ProSe network 100 comprises a remote UE 1 10, a ProSe UE-to-network relay 120, an eNodeB 1 30 and an evolved packet core (EPC) 140 associated with the eNodeB 130. In some embodiments, the eNodeB 130 together with the EPC 140 is referred to as the "network". In some embodiments, the EPC 140 comprises a mobility management entity (MME) and a serving gateway (S-GW). In some embodiments, the MME deals with the control plane of the LTE architecture. The MME handles the signaling related to mobility and security for the eNodeB access. The gateways, for example, the Serving GW deals with the user plane of the LTE architecture. The S-GW transports the IP data traffic between the User Equipment (UE) and the external networks. As shown in Fig. 1 , the remote UE 1 10 is generally considered out-of-coverage of the network, but may use relay support, through the ProSe UE-to-network relay 120 (sometimes referred to herein as "relay UE" 120 or "relay" 120) to access the network. Alternately, in other embodiments, the remote UE 1 1 0 may be in coverage of the network. The eNodeB 130 is configured to serve as a point of communication that the relay UE 120 may communicate with to access the EPC 140. The primary use case driving this scenario is public safety.

[0029] The remote UE 1 10 may access the network via the relay UE 120 using an interface called a "PC5" interface 150. PC5 interface 1 50 is a direct communication interface between two ProSe supported devices. Also, the relay UE 120 may connect to the eNodB 130 and thereby to the EPC 140 using a legacy Uu interface 1 60 (i.e., an air interface) between the relay UE 120 and the eNodeB 130. The eNodeB 130 may access the EPC140 using an S1 interface 180. In the embodiments where the remote UE is in coverage of the network, the remote UE may support connections over the PC5 interface 150 or a legacy Uu interface between the remote UE 1 1 0 and the eNodeB 130, simultaneously. In some embodiments, the remote UE 1 10 comprises a low power, low complexity device, for example, wearable UE such as smart watch, that preferably connects through relay UE 1 20 than directly connecting to the eNodeB 130 over the legacy Uu interface to save on consumed power. In some embodiments, the low power remote UE 1 10 relies on short range communication for the transfer of data in both uplink and downlink directions. In the embodiments described herein, it is assumed that the remote UE and the relay UE are aware of their paired association (for example, using discovery procedure). Further, in some embodiments, it is assumed that the remote UE 1 10 is in idle mode with respect to the radio resource control (RRC) over the Uu interface. In other words, the remote UE has no connection or bearers established with the network and uses PC5 interface to communicate with the network in order to save power. The relay UE 120 is assumed to be in-coverage substantially all the time. The relay UE can be in RRC idle mode or RRC connected mode.

[0030] The introduced LTE ProSe framework may be further enhanced to support general use cases that transport any type of data communication traffic in-between UEs and also to substantially improve network performance and user experience. Up to date, the ProSe design is primarily focused on public safety services, while the general use cases are mainly out of scope. Further enhancements to the sidelink air-interface (i.e., the PC5 interface 150) may be used for network optimization and have a potential to improve user experience and enlarge the amount of services. One of general purpose of device-to-device (D2D) communication, for example between the remote UE 1 1 0 and the relay UE 120, would be traffic management/offloading and utilization of its inherent multi-connectivity properties.

[0031] Embodiments disclosed herein relate to downlink reachability for remote UEs in-coverage and out-of-coverage with the network, in order to enable the remote UE to receive downlink (DL) data from the network. The basic principle is about how the remote UE 1 1 0 (i.e., a low power wearable UE) that is in-coverage but in idle mode can receive data via the relay UE 120 (which can be in idle mode or connected mode) over the PC5 interface 150. One way to achieve this is by L3 relaying, using the agreed Layer-3 Relay (i.e., IP router) to forward any type of IP traffic (e.g., data) between the remote UE 1 1 0 and the network using the EPS bearers of the relay UE 120. The relay UE 120 can have only a limited number of EPS bearers established and therefore, using the EPS bearers of the relay UE 120 to forward the IP traffic between the remote UE 1 10 and the network, limits the capacity of the network.

[0032] Alternative solutions include Layer-2 or L2 relaying, where the remote UE 1 1 0 forward any type of IP traffic (e.g., data) between the remote UE 1 10 and the network through the relay UE 120 using the EPS bearers established for the remote UE 1 20 within the network. That is, the remote UE 1 1 0 can send or receive data that can be mapped over its own EPS bearer in the network. In other embodiments, downlink reachability of remote UEs that are out-of-coverage of the network are also considered. In the current LTE system (as of Release 13), power optimizations and control plane enhancements to send or receive data over the PC5 interface is not considered.

[0033] In the embodiments described herein, different methods of downlink reachability of remote UEs that are in RRC idle mode over the PC5 interface 150 are proposed. In some embodiments, the remote UE is assumed to be in coverage of the network and in other embodiments, the remote UE is assumed to be out-of-coverage. In some embodiments, the proposed methods of downlink reachability enable the remote UE 1 1 0 to receive downlink (DL) data from the network through the relay UE 120. In particular, in one embodiment of the disclosure, a first method to receive DL data at the remote UE 1 1 0 from the eNodeB 130 based on a paging message (not shown) received from the eNodeB 130 is proposed. In this embodiment, the paging message is received from the eNodeB 130 over an air interface between the remote UE 1 1 0 and the eNodeB 130. In another embodiment of the disclosure, a second method to receive DL data at the remote UE 1 1 0 from the eNodeB 130 based on a paging message (not shown) received from the eNodeB 130 is proposed. In this embodiment, the paging message is received from the eNodeB 130 through the relay UE 130 over the PC5 interface 150.

[0034] Fig. 2 depicts downlink reachability of a remote UE 210 in a ProSe system 200 based on receiving a paging message from an eNodeB associated therewith over an air interface between the remote UE and the eNodeB, according to one embodiment of the disclosure. In some embodiments, the proposed method of downlink reachability enables the remote UE 21 0 to receive downlink (DL) data from the network through the relay UE 212. The ProSe system 200 comprises the remote UE 210, the relay UE 212, an eNodeB 214, an MME 21 6 and an S-GW 218. In some embodiments, the MME 216 and the S-GW 218 comprises an evolved packet core (EPC) or a "core network". In some embodiments, the eNodeB 214, the MME 216 and the S-GW 218 are together referred to as the "network". In some embodiments, it is assumed that both the remote UE 210 and the relay UE 21 2 are registered to the network via an initial attachment establishment procedure 21 9, prior to initiating the DL data transfer from the network to the remote UE 210 through the relay UE 212. In some embodiments, information on a paired association between the remote UE 210 and the relay UE 212 are provided to the network during the initial attachment establishment procedure 21 9. In some embodiments, the paired association between the remote UE 210 and the relay UE 21 2 is predetermined, while in other embodiments, the paired association is determined using other procedures, for example, discovery. In some embodiments, a paired association ID that identifies the paired association between the remote UE 210 and the relay UE 212 is generated at the MME 21 6 and provided to the remote UE 210 and the relay UE 212, during the initial attachment establishment procedure 219. The remote UE 210 is in RRC idle mode and the relay UE 212 is in RRC connected mode.

However, in other embodiments, the relay UE 212 can be in RRC idle mode. [0035] The DL data transfer to the remote UE 210 is initiated by the S-GW 218, when the S-GW 218 has DL data available for the remote UE 210. In some

embodiments, the DL data transfer is initiated by transmitting a DL notification message 221 comprising a remote ID associated with the remote UE 210, to the MME 216. In some embodiments, the DL notification message 221 further comprises EPS bearer IDs of the remote UE 210 and the relay UE 21 2. In some embodiments, the DL notification message 221 is generated at the S-GW 218 and provides an indication to the MME 216 on the availability of DL data for the remote UE 21 0. Upon receiving the DL notification message 221 , the MME 216 is configured to generate a paging message 223 based on the DL notification message 221 , for subsequent transmission to the eNodeB 214. In some embodiments, the paging message 223 comprises the remote ID of the remote UE 210 and the eNodeB 214 is further configured to transmit the paging message 223 to the remote UE 210 over an air interface between the eNodeB 214 and the remote UE 21 0. In some embodiments, the eNodeB 214 is configured to configure the remote UE 21 0 to check for paging messages over the air interface, in order to enable the remote UE 210 to receive DL data. In some embodiments, the remote UE 21 0 is configured to receive the paging message from the eNodeB 214 by monitoring a paging occasion of the remote UE 210. In some embodiments, the remote UE 210 is configured to monitor the paging occasion of the remote UE 210 based on the remote UE ID.

[0036] Upon receiving the paging message 223, the remote UE 210 is configured to generate a connection request message 220 comprising a cause value of paging or DL data. The remote UE 210 is further configured to transmit the connection request message 220 to the relay UE 21 2 over the PC5 interface between the remote UE 21 0 and the relay UE 212, to establish a direct communication with the relay UE 21 2, in order to receive the DL data through the relay UE 210. In some embodiments, the cause value of paging in the connection request message 220 indicates the receipt of the paging message at the remote UE 210. In some embodiments, the relay UE 212 is configured to generate and transmit a connection response message 222 to the remote UE 210, as an acknowledgement to receiving the connection request message 220. In the embodiments where the relay UE 212 is in RRC idle mode, the relay UE 21 2 is configured to establish its own RRC connection and enter RRC connected mode, upon receiving the connection request message 220 from the remote UE 210. In some embodiments, the relay UE 210 and the remote UE 212 are configured to perform a mutual authentication to confirm the paired association between the remote UE 210 and the relay UE 212. In some embodiments, establishing the RRC connection comprises setting up EPS bearers or the radio bearers, for example, signaling radio bearers (SRBs) for the UE in the network. In some embodiments, in the RRC idle mode, a UE (e.g., the relay UE 21 2) is known to the EPC but not to the eNodeB 214, whereas in the RRC connected mode, UE (e.g., the relay UE 21 2) is known both to the EPC and the eNodeB 214.

[0037] In some embodiments, the relay UE 21 2 is further configured to generate a sidelink UE information message 226 comprising the remote UE ID of the remote UE 21 0, for subsequent transmission to the eNodeB 214, in order to enable the remote UE 21 0 to be visible to the eNodeB 214 and the MME 216 associated therewith for DL data transfer. In some embodiments, in order to receive DL data at the remote UE 210 using L2 relaying, EPS bearers of the remote UE 210 have to be established in the network. During L3 relaying, the DL data is received at the remote UE 210 using EPS bearers for the relay UE 212 (already established when the relay UE 212 is in RRC connected mode). In some embodiments, the relay UE 21 2 is configured to handle a service request procedure to establish the EPS bearers of the remote UE 210, upon receiving the connection request message 220 from the remote UE 210.

[0038] In some embodiments, the service request procedure to establish the EPS bearers of the remote UE 21 0 is initiated or performed by the relay UE 21 2 on behalf of the remote UE 210. In such embodiments, the service request procedure is performed by the relay UE 212 by providing one or more messages comprising the relay UE ID and the paired association ID to the eNodeB 214, in order to enable S1 -U tunnel establishment 232 for the remote UE 21 0 in the core network. Alternatively, in other embodiments, the service request procedure to establish the EPS bearers of the remote UE 210 is performed by the remote UE 210 through the relay UE 212. In such embodiments, the remote UE 210 is configured to perform the service request procedure by generating one or more messages, for example, RRC connection establishment message, which are then carried within a container over the PC5 interface, and forwarded by the relay UE 212 transparently to the eNodeB 214 for further processing. The initiation of the EPS bearer establishment of the remote UE 21 0 based on the service request from the relay UE 212 implies that, with respect to the RRC connection establishment over the air interface (or with respect to the network), the remote UE 210 is still in RRC idle mode, however, the EPS bearer of the remote UE 21 0 is still activated to be used for data transfer in the S-GW - eNodeB - relay UE path.

[0039] In some embodiments, eNodeB 214 is configured to generate an S1 -AP message 228 comprising the remote UE ID of the remote UE 210 for subsequent transmission to the MME 216. In some embodiments, the S1 -AP message 228 is generated in response to receiving the sidelink UE information message 226 and provides an indication to the MME 216 on the receipt of the paging message 223 at the remote UE 21 0. In some embodiments, the S1 -AP message 228 further comprises the EPS bearer ID of the remote UE 210 during L2 relaying or the EPS bearer ID of the relay UE 212 during L3 relaying. In some embodiments, the S1 -AP message 228 provides information to the MME 21 6 on the EPS bearers to be utilized for the transmission of the DL data. Upon receiving the S1 -AP message 228, the MME 21 6 is further configured to generate a DL notification response message 234 for subsequent transmission to the S-GW. In some embodiments, the contents of the S1 -AP message 228 and the DL notification response message 234 are the same. Upon receiving the DL notification response message 234, the S-GW 218 is configured to transmit the DL data to the eNodeB 214 for subsequent transmission to the remote UE 21 0 through the relay UE 212. In some embodiments, the DL data is transmitted by the S-GW 218 using the EPS bearers of the remote UE 210 (e.g., L2 relaying), whereas, in other embodiments, the DL data is transmitted by the S-GW 218 using the EPS bearers of the relay UE 212 (e.g., L3 relaying).

[0040] In some embodiments, the relay UE 21 0 can go out-of-coverage of the network, after establishing the direct communication between the remote UE 210 and the relay UE 212 over the PC5 interface. In such embodiments, the remote UE 21 0 will continue to receive the DL data through the relay UE 21 2 until the remote UE 210 becomes inactive for a certain period of time. In such instances, the direct connection between the remote UE 210 and the relay UE 212 is released, and the remote UE 210 enters a newly defined PC5 idle mode. During the PC5 idle mode of the remote UE 21 0, the relay UE 212 buffers the DL data received from the eNodeB 214 until the remote UE 21 0 establishes a direct communication link with the relay UE 212. [0041] Alternatively, in some embodiments, since the remote UE uses preconfigured resources in out-of-coverage, a resource restriction pattern could be defined for each remote UE at which the remote UE could check for paging information containing the remote UE ID, in order to identify if the remote UE has any DL data intended for it.

Further, in some embodiments, the eNodeB 214 can buffer the DL data, if the relay UE 21 2 informs the eNodeB 214 about the PC5 idle mode of the remote UE 210. In some embodiments, relay UE 212 informs the eNodeB 214 about the PC5 idle mode of the remote UE 21 0, using the sidelink UE information message 226.

[0042] Fig. 3 depicts downlink reachability of a remote UE 310 in a ProSe system 300 based on receiving a paging message from an eNodeB associated therewith through a relay UE over a PC5 interface, according to one embodiment of the disclosure. In some embodiments, the proposed method of downlink reachability enables the remote UE 31 0 to receive downlink (DL) data from the network through the relay UE 312. The ProSe system 300 comprises the remote UE 310, the relay UE 312, an eNodeB 314, an MME 31 6 and an S-GW 318. In some embodiments, the MME 316 and the S-GW 318 comprises an evolved packet core (EPC) or a "core network". In some embodiments, the eNodeB 314, the MME 316 and the S-GW 318 are together referred to as the "network". In this embodiment, both the relay UE 312 and the remote UE 310 are assumed to be in coverage of the network. However, in other

embodiments, the remote UE 310 can go out-of-coverage of the network.

[0043] In some embodiments, it is assumed that both the remote UE 310 and the relay UE 312 are registered to the network via an initial attachment establishment procedure 319, prior to initiating the DL data transfer to the remote UE 31 0 through the relay UE 312. In some embodiments, the initial attachment procedure 319 is performed when the respective devices powers on. In some embodiments, a PDN connection and necessary bearers of the remote UE 31 0 and the relay UE 312 are established with the network during the initial attachment procedure 319. In some embodiments, information on a paired association between the remote UE 310 and the relay UE 31 2 are provided to the network during the initial attachment establishment procedure 31 9. In some embodiments, the paired association between the remote UE 310 and the relay UE 31 2 is predetermined, while in other embodiments, the paired association is determined using other procedures, for example, discovery. In some embodiments, a paired association ID that identifies the paired association between the remote UE 310 and the relay UE 312 is generated at the MME 31 6 and provided to the remote UE 310 and the relay UE 312, during the initial attachment establishment procedure 319. Once the initial attachment procedure 319 is completed, the remote UE 310 and the relay UE 312 enters RRC connected mode.

[0044] In some embodiments, once the remote UE 310 selects the relay UE 312 that it is associated with (e.g., via discovery), the remote UE 310 is configured to transmit a PC5 direct communication request message 320 over the PC5 interface to the relay UE 31 2, to establish a direct communication link between the remote UE 310 and the relay UE 312 over the PC5 interface and further for a mutual authentication to confirm the paired association between the remote UE 310 and the relay UE 312. In some embodiments, the PC5 direct communication request message 320 from the remote UE 320 further comprises a request for paired paging with the relay UE 31 2. In some embodiments, the PC5 direct communication request message 320 from the remote UE 31 0 enables to establish a paired paging at the relay UE 31 2 whereby the relay UE 312 can monitor a paging occasion of the remote UE 31 0, in order to receive a paging message for the remote UE 31 0 from the MME 316.

[0045] In some embodiments, the PC5 direct communication request message 320 further comprises the remote UE ID to enable the relay UE to calculate the paging occasion (i.e., the paging frame and subframe to monitor) of the remote UE 310, as defined in 3GPP specification TS36.304. Upon establishing paired paging between the remote UE 31 0 and the relay UE 312, either the remote UE 310 or the relay UE 312 is configured to transmit a paired paging indication message, for example, the paired paging indication message 312b or the paired paging indication message 312a, to inform the eNodeB 314 about the paired paging status. In some embodiments, the paired paging indication message 321 a or 321 b comprises a new or existing radio resource control (RRC) message and comprises information on the UE ID (i.e., the relay UE ID for the message 321 a or the remote UE ID for the message 321 b), the paired association id, an identifying information on whether the transmitting UE is the relay UE 31 2 or the remote UE 310 and an implicit/explicit paired paging indication.

[0046] In some embodiments, upon establishing the paired paging indication message 321 , either the remote UE 31 0 or the relay UE 312 is further configured to inform the MME 316 about the paired paging status using a tracking area update (TAU) procedure, defined in the 3GPP specification TS23.401 and TS24.301 . In some embodiments, the paired paging indication message 321 a or 321 b is further configured to inform the eNodeB 314 about a release of the paired paging status between the remote UE 31 0 and the relay UE 312, when the paired paging between the remote UE 31 0 and the relay UE 312 is released. In such embodiments, the paired paging indication message 321 a or 321 b comprises information on the UE ID (i.e., the relay UE ID for the message 321 a or the remote UE ID for the message 321 b), the paired association id, an identifying information on whether the transmitting UE is the relay UE 31 2 or the remote UE 310 and an implicit/explicit release of paired paging indication.

[0047] In some embodiments, once there is data inactivity at the relay UE 312, the RRC connection of the relay UE 312 is released. Further, the PC5 communication link between the relay UE 312 and the remote UE 310 is also released and both the remote UE 310 and the relay UE 31 2 enters RRC idle mode. In some embodiments, once the relay UE 312 enters the RRC idle mode, the relay UE 312 is configured to check for a paging message 323 for the remote UE 310 from the eNodeB 314, based on the established paired paging status. In other embodiments, even if the relay UE 312 is in RRC connected mode, the relay UE 312 is configured to check for a paging message 323 for the remote UE 310 from the eNodeB 314, based on the established paired paging status. In some embodiments, the paging message 323 indicates the availability of a downlink (DL) data for the remote UE 310. In some embodiments, the relay UE 31 2 is configured to monitor a paging occasion of the relay UE 312 only, in order to receive the paging message 323. In some embodiments, the paging message 323 comprises a paging message associated with the remote UE and a paging message associated with the relay UE. In some embodiments, the paging occasion of the relay UE 312 is calculated using the relay UE ID as defined in the 3GPP specification TS36.304. Alternatively, in other embodiments, the relay UE 31 2 is configured to monitor both the paging occasion of the relay UE 31 2 and the paging occasion of the remote UE 31 0. In such embodiments, the relay UE 312 is configured to monitor the paging occasion of the remote UE 310, in order to receive the paging message associated with the remote UE. In some embodiments, the paging occasion of the relay UE 312 is calculated using the relay UE ID and the paging occasion of the remote UE 310 is calculated using the remote UE ID as defined in the 3GPP specification TS36.304.

[0048] The DL data transfer to the remote UE 310 is initiated by the S-GW 318, when the S-GW 318 has DL data available for the remote UE 310. In some

embodiments, the DL data transfer is initiated transmitting a DL data notification message 324 comprising a remote ID associated with the remote UE 310, to the MME 31 6. In some embodiments, the DL data notification message 324 further comprises EPS bearer IDs of the remote UE 310 and the relay UE 312. In some embodiments, the DL data notification message 324 is generated at the S-GW 218 and provides an indication to the MME 31 6 on the availability of DL data for the remote UE 310. Upon receiving the DL data notification message 324, the MME 316 is configured to generate a paging message 323 for the remote UE 310, based on the DL data notification message 324. The MME 316 is further configured to transmit the paging message 323 to the eNodeB 314 (i.e., the eNodeB that belongs to a tracking area to which the relay UE 312 is registered) based on the information of the paired paging status of the remote UE 310 and the relay UE 31 2.

[0049] In some embodiments, the eNodeB 314 is configured to forward or send the paging message 323 received from the MME 316 to the relay UE 31 2 for subsequent transmission to the remote UE 310, at the paging occasion of the relay UE 31 2. In some embodiments, the paging message 323 comprises a paging information for the relay UE 312 and the remote UE 310, and the paging occasion of the relay UE 312 is determined using the relay UE ID as defined in the 3GPP specification TS36.331 .

Alternatively, in other embodiments, the eNodeB 314 is configured to forward or send the paging message 323 received from the MME 31 6 to the relay UE 312 for subsequent transmission to the remote UE 310, at the paging occasion of the remote UE 310 determined based on the remote UE ID. In such embodiments, if the paging occasion of the remote UE 310 is different from the paging occasion of the relay UE 31 2, then the paging message as defined in the 3GPP specification TS36.331 contains only the paging information for the remote UE 310.

[0050] Upon receiving the paging message 323, the relay UE 312 performs the service request procedure 329 for the relay UE 312 and enters the RRC connected mode. In some embodiments, entering the RRC connected mode enables the relay UE 31 2 to transfer the paging message 323 to the remote UE 310. In some embodiments, the paging message 323 is transmitted from the relay UE 312 to the remote UE 31 0 based on a periodic discovery message using physical downlink shared channel (PSDCH). In such embodiments, the remote UE 310 is configured to monitor a periodic announcement message (e.g., configured for every N seconds) comprising the periodic discovery message from the relay UE 31 2, in order to receive the paging message 323 from the eNodeB 314. In some embodiments, the paging message 323 is transmitted from the relay UE 31 2 to the remote UE 31 0 using one or more discovery resource elements of a pre-configured resource pattern with paging occasion (PO) that the remote UE 31 0 is monitoring.

[0051] In some embodiments, the paging message 323 is transmitted from the relay UE 312 to the remote UE 310 using a sidelink paging control channel over the PC5 interface defined for conveying downlink paging information and system information that the remote UE 310 checks periodically. In such embodiments, the relay UE 312 may divide the remote UE 310 to different paging occasions in time over the PC5 interface by allocating a periodicity with which to check the paging from the relay UE 312.

Further, in some embodiments, the paging message 323 is transmitted from the relay UE 312 to the remote UE 310 directly over the PC5 interface using resources configured by the eNodeB 314 for relay communication that the remote UE 310 periodically checks or reads.

[0052] Upon receiving the paging message 323, the remote UE 310 is configured to generate a connection request message 325 comprising a cause value of paging or DL data. The remote UE 310 is further configured to transmit the connection request message 325 to the relay UE 31 2 over the PC5 interface between the remote UE 310 and the relay UE 312, to establish a direct communication with the relay UE 31 2, in order to receive the DL data through the relay UE 310. In some embodiments, the cause value of paging in the connection request message 325 indicates the receipt of the paging message 323 at the remote UE 310. In some embodiments, the relay UE 31 2 is configured to generate and transmit a connection response message 327 to the remote UE 31 0, as an acknowledgement to receiving the connection request message 325. In some embodiments, the relay UE 31 0 and the remote UE 312 are configured to perform a mutual authentication to confirm the paired association between the remote UE 310 and the relay UE 31 2.

[0053] In some embodiments, the relay UE 31 2 is further configured to generate a sidelink UE information message 326 comprising the remote UE ID of the remote UE 31 0, for subsequent transmission to the eNodeB 314, in order to enable the remote UE 31 0 to be visible to the eNodeB 314 and the MME 316 associated therewith for DL data transfer. In some embodiments, the sidelink UE information message 326 is further configured to configure the eNodeB 314 to generate communication resources for the remote UE 31 0. In some embodiments, a sidelink UE response message (not shown) comprising the generated configuration parameters is transmitted from the eNodeB 314 to the relay UE 312, for subsequent transmission to the remote UE 310 over the PC5 interface. In some embodiments, in order to receive DL data at the remote UE 310 using L2 relaying, EPS bearers of the remote UE 310 have to be established in the network. During L3 relaying, the DL data is received at the remote UE 31 0 using EPS bearers for the relay UE 312 (already established when the relay UE 312 entered RRC connected mode). In some embodiments, the relay UE 312 is configured to handle a service request procedure to establish the EPS bearers of the remote UE 310, upon receiving the connection request message 325 from the remote UE 310.

[0054] In some embodiments, the service request procedure to establish the EPS bearers of the remote UE 31 0 is initiated or performed by the relay UE 31 2 on behalf of the remote UE 310. In such embodiments, the service request procedure 331 is performed by the relay UE 312 by providing one or more messages comprising the relay UE ID (e.g., S-TMSI) and the paired association ID to the eNodeB 314, in order to enable S1 -U tunnel establishment 332 for the remote UE 310 in the core network.

Alternatively, in other embodiments, the service request procedure to establish the EPS bearers of the remote UE 31 0 is performed by the remote UE 310 through the relay UE 31 2. In such embodiments, the remote UE 310 is configured to perform the service request procedure 333 by generating one or more messages, for example, RRC connection establishment message, which are then carried within a container over the PC5 interface, and forwarded by the relay UE 312 transparently to the eNodeB 314 for further processing. The initiation of the EPS bearer establishment of the remote UE 31 0 based on the service request from the relay UE 312 implies that, with respect to the RRC connection establishment over the air interface (or with respect to the network), the remote UE 310 is still in RRC idle mode, however, the EPS bearer of the remote UE 31 0 is still activated to be used for data transfer in the S-GW - eNodeB - relay UE path.

[0055] In some embodiments, eNodeB 314 is configured to generate an S1 -AP message 328 comprising the remote UE ID of the remote UE 310 for subsequent transmission to the MME 316. In some embodiments, the S1 -AP message 328 is generated in response to receiving the sidelink UE information message 326 and provides an indication to the MME 316 on the receipt of the paging message 323 at the remote UE 31 0. In some embodiments, the S1 -AP message 328 further comprises the EPS bearer ID of the remote UE 310 during L2 relaying or the EPS bearer ID of the relay UE 312 during L3 relaying. In some embodiments, the S1 -AP message 328 provides information to the MME 31 6 on the EPS bearers to be utilized for the transmission of the DL data. Upon receiving the S1 -AP message 328, the MME 31 6 is further configured to generate a DL data notification response message 334 for subsequent transmission to the S-GW 318. In some embodiments, the contents of the S1 -AP message 328 and the DL data notification response message 334 are the same. Upon receiving the DL data notification response message 334, the S-GW 318 is configured to transmit the DL data to the eNodeB 314 for subsequent transmission to the remote UE 310 through the relay UE 312. In some embodiments, the DL data is transmitted by the S-GW 318 using the EPS bearers of the remote UE 310 (e.g., L2 relaying), whereas, in other embodiments, the DL data is transmitted by the S-GW 318 using the EPS bearers of the relay UE 312 (e.g., L3 relaying).

[0056] In some embodiments, the relay UE 310 can go out-of-coverage of the network, after establishing the direct communication between the remote UE 310 and the relay UE 312 over the PC5 interface. In such embodiments, the remote UE 31 0 will continue to receive the DL data through the relay UE 312 until the remote UE 310 becomes inactive for a certain period of time. In such instances, the direct connection between the remote UE 310 and the relay UE 312 is released, and the remote UE 310 enters a newly defined PC5 idle mode. During the PC5 idle mode of the remote UE 31 0, the relay UE 312 buffers the DL data received from the eNodeB 314 until the remote UE 31 0 establishes a direct communication link with the relay UE 312. [0057] Alternatively, in some embodiments, since the remote UE uses preconfigured resources in out-of-coverage, a resource restriction pattern could be defined for each remote UE at which the remote UE could check for paging information containing the remote UE ID, in order to identify if the remote UE has any DL data intended for it. Further, in some embodiments, the eNodeB 314 can buffer the DL data, if the relay UE 31 2 informs the eNodeB 314 about the PC5 idle mode of the remote UE 310. In some embodiments, relay UE 312 informs the eNodeB 314 about the PC5 idle mode of the remote UE 31 0, using the sidelink UE information message 326.

[0058] Fig. 4 illustrates a block diagram of an apparatus 400 for use in a remote or wearable user equipment (UE) in a ProSe system, that facilitates downlink reachability of the remote UE, according to the various embodiments described herein. In some embodiments, the downlink reachability of the remote UE is achieved based on receiving the paging message from an eNodeB over an air interface between the remote UE and the eNodeB. Alternatively, in other embodiments, the downlink reachability of the remote UE is achieved based on receiving the paging message from the eNodeB through a relay UE over a PC5 interface between the relay UE and the remote UE. The remote UE is described herein with reference to the remote UE 210 in Fig. 2 for the embodiment where the paging message is received over the air interface and with reference to the remote UE 310 in Fig. 3 for the embodiment where the paging message is received through the relay UE.

[0059] The apparatus 400 includes a receiver circuit 410, a processing circuit 430, and a transmitter circuit 420. Further, in some embodiments, the apparatus 400 comprises a memory circuit 440 coupled to the processing circuit 430. Each of the receiver circuit 410 and the transmitter circuit 420 are configured to be coupled to one or more antennas, which can be the same or different antenna(s). In some

embodiments, the receiver circuit 410 and transmitter circuit 420 can have one or more components in common, and both can be included within a transceiver circuit, while in other aspects they are not. In various embodiments, the apparatus 400 can be included within a UE, for example, with apparatus 400 (or portions thereof) within a receiver and transmitter or a transceiver circuit of a UE.

[0060] To enable downlink reachability in remote UEs in ProSe systems, the processing circuit 430 of the apparatus 400 is configured to receive a paging message (e.g., the paging message 223 in Fig. 2 or the paging message 323 in Fig. 3) from an eNodeB or an MME associated therewith via the receive circuit 410. In some embodiments, the apparatus 400 could be included within the remote UE 21 0 of Fig. 2. In such embodiments, the paging message (e.g., the paging message 223 in Fig. 2) is received directly from the eNodeB (e.g., eNodeB 214 in Fig. 2) at the processing circuit 430 over an air interface between the eNodeB and the remote UE. Upon receiving the paging message, the processing circuit 430 is configured to generate a connection request message (e.g., the connection request message 220) comprising a cause value of paging or DL data. The processing circuit 430 is further configured to transmit the connection request message to the relay UE over the PC5 interface between the remote UE 21 0 and the relay UE via the transmit circuit 420, to establish a direct communication with the relay UE, in order to receive the DL data through the relay UE. In some embodiments, the processing circuit 430 is further configured to receive a connection response message (e.g., the connection response message 222) from the relay UE via the receive circuit 410, as an acknowledgement to transmitting the connection request message 220. In some embodiments, the memory circuit 440 is configured to store a remote UE ID associated with the remote UE (e.g., the remote UE 21 0) and a paired association ID (obtained during the initial attach procedure indicated above) indicating a paired association of the remote UE with the relay UE (e.g., the relay UE 212).

[0061] In some embodiments, the processing circuit 430 is further configured to initiate a service request procedure to establish the EPS bearers of the remote UE in the network, upon establishing a direct communication with the relay UE. In such embodiments, the processing circuit 430 is configured to perform the service request procedure (e.g., the service request procedure 233) by generating one or more messages, for example, RRC connection establishment message, which are then transmitted via the transmit circuit 420 within a container over the PC5 interface to the relay UE for subsequent transmission to the eNodeB. Once the EPS bearer of the remote UE is established in the network, the processing circuit 430 is configured to receive DL data from the eNodeB through the relay UE, using the EPS bearer of the remote UE during L2 relaying. In some embodiments, the processing circuit 430 is configured to receive DL data from the eNodeB through the relay UE, using the EPS bearer of the relay UE during L3 relaying. [0062] In some embodiments, the apparatus 400 could be included within the remote UE 310 of Fig. 3. In such embodiments, the paging message (e.g., the paging message 323 in Fig. 3) is received from the eNodeB (e.g., eNodeB 314 in Fig. 3) through a relay UE (e.g., the relay UE 312 in Fig. 3) at the processing circuit 430 over a PC5 interface between the relay UE and the remote UE. In some embodiments, the processing circuit 430 is configured to monitor a periodic discovery message from the relay UE, in order to receive the paging message through the relay UE. In some embodiments, the processing circuit 430 is configured to monitor one or more discovery resource elements of a pre-configured resource pattern of the relay UE, in order to receive the paging message through the relay UE. In some embodiments, the processing circuit 430 is configured to periodically monitor a sidelink paging control channel over the PC5 interface defined for conveying downlink paging information and system information, in order to receive the paging message through the relay UE.

[0063] In some embodiments, the memory circuit 440 is configured to store a remote UE ID associated with the remote UE (e.g., the remote UE 310) and a paired association ID (obtained during the initial attach procedure indicated above) indicating a paired association of the remote UE with the relay UE (e.g., the relay UE 312). In some embodiments, the processing circuit 430 is configured to receive the paging message through the relay UE, based on a paired paging association between the remote UE and the relay UE. In some embodiments, the processing circuit 430 is configured to transmit a PC5 direct communication request message (e.g., the PC5 direct

communication request message 320) via the transmit circuit 420 to the relay UE, prior to receiving the paging message from the relay UE, in order to establisg the paired paging between the remote UE and the relay UE. In some embodiments, the PC5 direct communication request message from the remote UE comprises a request for paired paging with the relay UE. Upon establishing the paired paging between the remote UE and the relay UE, the processing circuit 430 is configured to selectively transmit a paired paging indication message (e.g., the paired paging indication message 321 ) to inform the eNodeB about the paired paging status.

[0064] Upon receiving the paging message from the eNodeB through the relay UE, the processing circuit 430 is configured to generate a connection request message (e.g., the connection request message 325) comprising a cause value of paging or DL data. The processing circuit 430 is further configured to transmit the connection request message to the relay UE over the PC5 interface between the remote UE and the relay UE via the transmit circuit 420, to establish a direct communication with the relay UE, in order to receive the DL data through the relay UE. In some embodiments, the processing circuit 430 is further configured to receive a connection response message (e.g., the connection response message 327) from the relay UE via the receive circuit 41 0, as an acknowledgement to transmitting the connection request message.

[0065] In some embodiments, the processing circuit 430 is further configured to initiate a service request procedure to establish the EPS bearers of the remote UE in the network, upon establishing a direct communication with the relay UE. In such embodiments, the processing circuit 430 is configured to perform the service request procedure (e.g., the service request procedure 333) by generating one or more messages, for example, RRC connection establishment message, which are then transmitted via the transmit circuit 420 within a container over the PC5 interface to the relay UE for subsequent transmission to the eNodeB. Once the EPS bearer of the remote UE is established in the network, the processing circuit 430 is configured to receive DL data from the eNodeB through the relay UE, using the EPS bearer of the remote UE during L2 relaying. In some embodiments, the processing circuit 430 is configured to receive DL data from the eNodeB through the relay UE, using the EPS bearer of the relay UE during L3 relaying.

[0066] Fig. 5 illustrates a block diagram of an apparatus 500 for use in a relay user equipment (UE) in a ProSe system, that facilitates downlink reachability in a remote UE associated therewith, according to the various embodiments described herein. In some embodiments, the downlink reachability of the remote UE is achieved based on conveying a downlink (DL) data associated with the remote UE through the relay UE. Alternatively, in other embodiments, the downlink reachability of the remote UE is achieved based on conveying a paging message associated with the remote UE and also, conveying a downlink (DL) data associated with the remote UE through the relay UE. The apparatus 500 includes a receiver circuit 510, a processing circuit 530, and a transmitter circuit 520. Further, in some embodiments, the apparatus 500 comprises a memory circuit 540 coupled to the processing circuit 530. Each of the receiver circuit 51 0 and the transmitter circuit 520 are configured to be coupled to one or more antennas, which can be the same or different antenna(s). In some embodiments, the receiver circuit 510 and transmitter circuit 520 can have one or more components in common, and both can be included within a transceiver circuit, while in other aspects they are not. In various embodiments, the apparatus 500 can be included within a UE, for example, with apparatus 500 (or portions thereof) within a receiver and transmitter or a transceiver circuit of a UE.

[0067] In some embodiments, the apparatus 500 could be included within the relay UE 212 of Fig. 2. The processing circuit 530 is configured to receive a connection request message (e.g., the connection request message 220) via the receive circuit 51 0, from a remote UE (e.g., the remote UE 210). In some embodiments, the processing circuit 530 is configured to establish a direct connection between the relay UE and the remote UE, based on the connection request message. The processing circuit 530 is further configured to generate and transmit a connection response message (e.g., the connection response message 222) to the remote UE via the transmit circuit 520, as an acknowledgement to receiving the connection request message. In some embodiments, the processing circuit 530 is further configured to generate a sidelink UE information message (e.g., sidelink UE information message 226) comprising the remote UE ID of the remote UE, upon establishing a direct communication with the remote UE, for subsequent transmission to the eNodeB (e.g. the eNodeB 214) via the transmit circuit 520, in order to enable the remote UE to be visible to the eNodeB and an MME (e.g., the MME 21 6) associated therewith for DL data transfer. In some embodiments, the relay UE is further configured to handle a service request procedure to establish the EPS bearers of the remote UE, upon receiving the connection request message from the remote UE.

[0068] In some embodiments, the processing circuit 540 is configured to perform the service request procedure (e.g., the service request procedure 231 ) for the remote UE, by providing one or more messages comprising the relay UE ID and the paired association ID to the eNodeB via the transmit circuit 520, in order to enable S1 -U tunnel establishment 232 for the remote UE in the core network. Alternatively, in other embodiments, the processing circuit 540 is configured to perform the service request procedure (e.g., the service request procedure 233) by forwarding one or more messages from the remote UE to the eNodeB for further processing. Once the EPS bearer of the remote UE is established in the network, the processing circuit 530 is configured to receive DL data from the eNodeB, using the EPS bearer of the remote UE during L2 relaying, for subsequent transmission to the remote UE using the transmit circuit 520. In some embodiments, the processing circuit 530 is configured to receive DL data from the eNodeB, using the EPS bearer of the relay UE during L3 relaying. In some embodiments, the processing circuit 530 is further configured to buffer the DL data for a predetermined period of time, upon a release of the direct connection between the remote UE and the relay UE.

[0069] In some embodiments, the apparatus 500 could be included within the relay UE 312 of Fig. 3. The processing circuit 530 is configured to receive a connection request message (e.g., the connection request message 325) via the receive circuit 51 0, from a remote UE (e.g., the remote UE 310). In some embodiments, the processing circuit 530 is configured to establish a direct connection between the relay UE and the remote UE, based on the connection request message. In some

embodiments, the processing circuit 530 is configured to receive the connection request message from the remote UE, in response to transmitting a paging message (e.g., the paging message 323) from the processing circuit 530 to the remote UE. In some embodiments, the processing circuit 530 is configured to transmit the paging message received from the eNodeB to the remote UE using periodic discovery message. In some embodiments, the processing circuit 530 is configured to transmit the paging message received from the eNodeB to the remote UE using one or more discovery resource elements of a pre-configured resource pattern of the relay UE. In some embodiments, the processing circuit 530 is configured to transmit the paging message received from the eNodeB to the remote UE using a sidelink paging control channel over the PC5 interface defined for conveying downlink paging information and system information.

[0070] In some embodiments, the processing circuit 530 is configured to receive the paging message from an eNodeB (e.g., the eNodeB 314) associated therewith for subsequent transmission to the remote UE via the transmit circuit 520, based on a paired paging association between the remote UE and the relay UE. In some embodiments, the paging message associated with the remote UE is received from the eNodeB at the processing circuit 530 based on monitoring a paging occasion of the remote UE or a paging occasion of the relay UE. In some embodiments, the processing circuit 530 is further configured to receive a PC5 direct communication request message (e.g., the PC5 direct communication request message 320) via the receive circuit 51 0, prior to transmitting the paging message to the remote UE, in order to establish the paired paging between the remote UE and the relay UE. In some embodiments, the PC5 direct communication request message from the remote UE comprises a request for paired paging with the relay UE. Upon establishing the paired paging between the remote UE and the relay UE, the processing circuit 530 is configured to selectively transmit a paired paging indication message (e.g., the paired paging indication message 321 a) to inform the eNodeB about the paired paging status.

[0071] In some embodiments, the processing circuit 530 is further configured to generate and transmit a connection response message (e.g., the connection response message 327) to the remote UE via the transmit circuit 520, as an acknowledgement to receiving the connection request message. In some embodiments, the processing circuit 530 is further configured to generate a sidelink UE information message (e.g., sidelink UE information message 326) comprising the remote UE ID of the remote UE, upon establishing a direct communication with the remote UE, for subsequent transmission to the eNodeB (e.g. the eNodeB 314) via the transmit circuit 520, in order to enable the remote UE to be visible to the eNodeB and an MME (e.g., the MME 31 6) associated therewith, for DL data transfer. In some embodiments, the processing circuit 530 is further configured to handle a service request procedure to establish the EPS bearers of the remote UE, upon receiving the connection request message from the remote UE.

[0072] In some embodiments, the memory circuit 540 is configured to store a relay UE ID associated with the relay UE (e.g., the relay UE 312), the remote UE ID associated with the remote UE (i.e., the remote UE 310) and a paired association ID (obtained during the initial attach procedure indicated above) indicating a paired association of the remote UE with the relay UE (e.g., the relay UE 312). In some embodiments, the processing circuit 540 is configured to perform the service request procedure (e.g., the service request procedure 331 ) for the remote UE by providing one or more messages comprising the relay UE ID and the paired association ID to the eNodeB via the transmit circuit 520, in order to enable S1 -U tunnel establishment 332 for the remote UE in the core network. Alternatively, in other embodiments, the processing circuit 540 is configured to perform the service request procedure (e.g., the service request procedure 333) by forwarding one or more messages from the remote UE to the eNodeB for further processing. Once the EPS bearer of the remote UE is established in the network, the processing circuit 530 is configured to receive DL data from the eNodeB, using the EPS bearer of the remote UE during L2 relaying, for subsequent transmission to the remote UE using the transmit circuit 520. In some embodiments, the processing circuit 530 is configured to receive DL data from the eNodeB, using the EPS bearer of the relay UE during L3 relaying. In some

embodiments, the processing circuit 530 is further configured to buffer the DL data for a predetermined period of time, upon a release of the direct connection between the remote UE and the relay UE.

[0073] Fig. 6 illustrates a block diagram of an apparatus 600 for use in an eNodeB in a ProSe system, that facilitates downlink reachability in a remote UE associated therewith, according to the various embodiments described herein. In some

embodiments, the downlink reachability of the remote UE is achieved based on transmitting a paging message associated with the remote UE from the eNodeB over an air interface between the remote UE and the eNodeB, and transmitting a downlink (DL) data associated with the remote UE from the eNodeB through a relay UE associated therewith. Alternatively, in other embodiments, the downlink reachability of the remote UE is achieved based on transmitting a paging message associated with the remote UE from the eNodeB through the relay UE over a PC5 interface between the relay UE and the remote UE, and transmitting a downlink (DL) data associated with the remote UE from the eNodeB through the relay UE.

[0074] The apparatus 600 includes a receiver circuit 620, a processing circuit 630, and a transmitter circuit 610. Further, in some embodiments, the apparatus 600 comprises a memory circuit 640 coupled to the processing circuit 630. Each of the receiver circuit 620 and the transmitter circuit 610 are configured to be coupled to one or more antennas, which can be the same or different antenna(s). Further, in some embodiments, the apparatus comprises a memory circuit 640 coupled to the processing circuit 630. In some embodiments, the receiver circuit 620 and the transmitter circuit 61 0 can have one or more components in common, and both can be included within a transceiver circuit, while in other aspects they are not. In various embodiments, the apparatus 600 can be included within an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (Evolved NodeB, eNodeB, or eNB).

[0075] In some embodiments, the apparatus 600 could be included within the eNodeB 214 of Fig. 2. In such embodiments, the processing circuit 630 is configured to transmit a paging message (e.g., the paging message 223) associated with a remote UE (e.g., the remote UE 210) to the remote UE via the transmit circuit 61 0 over an air interface between the remote UE and the eNodeB. In some embodiments, the memory circuit 640 is configured to store a relay UE ID associated with the relay UE (e.g., the relay UE 212) and a remote ID associated with the remote UE (e.g., the remote UE 210) obtained during the initial attach procedure indicated above. In some embodiments, the processing circuit 630 is configured to transmit the paging message to the remote UE at a paging occasion of the remote UE determined based on the remote UE ID.

[0076] In some embodiments, the processing circuit 630 is configured to receive the paging message from an MME (e.g., the MME 216) associated therewith, prior to transmitting the paging message to the remote UE. In some embodiments, the paging message from the eNodeB provides an indication of the availability of downlink (DL) data for the remote UE. In some embodiments, the processing circuit 630 is further configured to receive a sidelink UE information message (e.g., the sidelink UE information message 226) from the relay UE (e.g., the relay UE 212) via the receive circuit 620, in response to transmitting the paging message to the remote UE. In some embodiments, the sidelink UE information message indicates a receipt of the paging message at the remote UE or an establishment of a direct connection between the remote UE and the relay UE or both. In some embodiments, the sidelink UE

information message indicates a release of the direct connection between the remote UE and the relay UE.

[0077] In some embodiments, the processing circuit 630 is further configured to receive one or more messages from the remote UE (via the relay UE) or directly from the relay UE, in order to establish EPS bearers of the remote UE in the network. Upon receiving the one or more messages (i.e., via the service request procedure 231 or 233), the processing circuit 630 establishes the EPS bearer of the remote UE in the network. Upon receiving the sidelink UE information message, the processing circuit is further configured to generate an S1 -AP message (e.g., the S1 -AP message 228) for subsequent transmission to the MME via the transmit circuit 610. In some

embodiments, the S1 -AP message comprises the remote UE ID to indicate the receipt of the paging message at the remote UE. In some embodiments, the S1 -AP message further comprises information on the EPS bearer ID of the EPS bearers of the relay UE or the remote UE to be utilized for sending the DL data to the remote UE. The processing circuit 630 is further configured to forward the DL data for the remote UE from the MME to the relay UE via the transmit circuit 61 0 using the EPS bearers of the remote UE for L2 relaying and using the EPS bearers of the relay UE for L3 relaying.

[0078] In some embodiments, the apparatus 600 could be included within the eNodeB 314 of Fig. 3. In such embodiments, the processing circuit 630 is configured to transmit a paging message (e.g., the paging message 323) associated with a remote UE (e.g., the remote UE 310) to a relay UE (e.g., the relay UE 312) via the transmit circuit 61 0, based on a paired paging association between the remote UE and the relay UE. In some embodiments, the processing circuit 630 is further configured to receive a paired paging indication message (e.g., the paired paging indication message 321 a or 31 2b) from the relay UE or the remote UE, via the receive circuit 620, prior to transmitting the paging message to the relay UE. In some embodiments, the paired paging indication message provides information on the paired paging association between the relay UE and the remote UE to the eNodeB.

[0079] In some embodiments, the memory circuit 640 is configured to store a relay UE ID associated with the relay UE (e.g., the relay UE 312) and a remote ID associated with the remote UE (e.g., the remote UE 310) obtained during the initial attach procedure indicated above. In some embodiments, the processing circuit 630 is configured to transmit the paging message associated with the remote UE to the relay UE at a paging occasion of the relay UE determined based on the relay UE ID.

Alternatively, in other embodiments, the processing circuit 630 is configured to transmit the paging message associated with the remote UE to the relay UE at the paging occasion of the remote UE determined based on the remote UE ID.

[0080] In some embodiments, the processing circuit 630 is configured to receive the paging message from an MME (e.g., the MME 316) associated therewith, prior to transmitting the paging message to the relay UE. In some embodiments, the paging message from the eNodeB provides an indication of the availability of downlink (DL) data for the remote UE. In some embodiments, the processing circuit 630 is further configured to receive a sidelink UE information message (e.g., the sidelink UE information message 326) from the relay UE (e.g., the relay UE 312) via the receive circuit 620, in response to transmitting the paging message to the relay UE. In some embodiments, the sidelink UE information message indicates a receipt of the paging message at the remote UE or an establishment of a direct connection between the remote UE and the relay UE or both. In some embodiments, the sidelink UE

[0081] In some embodiments, the processing circuit 630 is further configured to receive one or more messages from the remote UE (via the relay UE) or from the relay UE on behalf of the remote UE, in order to establish EPS bearers of the remote UE in the network. Upon receiving the one or more messages (associated with the service request procedure 331 or 333), the processing circuit 630 establishes the EPS bearer of the remote UE in the network. Upon receiving the sidelink UE information message, the processing circuit is further configured to generate an S1 -AP message (e.g., the S1 -AP message 328) for subsequent transmission to the MME via the transmit circuit 610. In some embodiments, the S1 -AP message comprises the remote UE ID to indicate the receipt of the paging message at the remote UE. In some embodiments, the S1 -AP message further comprises information on the EPS bearer ID of the EPS bearers of the relay UE or the remote UE to be utilized for sending the DL data to the remote UE. Upon receiving the S1 -AP message, the processing circuit 630 is configured to forward the DL data for the remote UE from the MME to the relay UE via the transmit circuit 61 0 using the EPS bearers of the remote UE for L2 relaying and using the EPS bearers of the relay UE for L3 relaying.

[0082] Fig. 7 illustrates a flowchart of a method 700 for a remote UE in a ProSe system comprising a relay UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. The method 700 is described herein with reference to the apparatus 400 in Fig. 4 and the ProSe system 200 in Fig. 2. In some embodiments, the apparatus 400 is included within the remote UE 210 of the ProSe system 200. At 702, a remote UE ID associated with the remote UE and a paired association ID (obtained at initial attach) indicating a paired association of the remote UE with the relay UE is stored in the memory circuit 440 of the remote UE. At 704, a paging message comprising the remote UE ID of the remote UE is received from the eNodeB at the processing circuit 430 via the receive circuit 41 0, over an air interface between the eNodeB and the remote UE. In some embodiments, the paging message indicates the remote UE about an availability of a downlink (DL) data for the remote UE.

[0083] At 706, a connection request message comprising a cause value for paging is generated at the processing circuit 430, for subsequent transmission via the transmit circuit 420 to the relay UE over a PC5 interface between the remote UE and the relay UE, in response to receiving the paging message. In some embodiments, the connection set up message is configured to configure the relay UE to establish a PC5 direct connection between the remote UE and the relay UE, in order to receive the DL data through the relay UE. At 708, a service request procedure to establish an EPS bearer of the remote UE in the network through the relay UE is selectively initiated at the processing circuit 430, upon establishing the PC5 direct connection between the remote UE and the relay UE. In other embodiments, the service request procedure to establish the EPS bearer of the remote UE in the network is initiated by the relay UE. At 710, a downlink data signal comprising the DL data is received at the processing circuit 430 via the receive circuit 410, through the relay UE over the PC5 interface using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[0084] Fig. 8 illustrates a flowchart of a method 800 for a remote UE in a ProSe system comprising a relay UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. The method 800 is described herein with reference to the apparatus 400 in Fig. 4 and the ProSe system 300 in Fig. 3. In some embodiments, the apparatus 400 is included within the remote UE 310 of the ProSe system 200. At 802, a remote UE ID associated with the remote UE and a paired association ID (obtained at initial attach) indicating a paired association of the remote UE with the relay UE is stored in the memory circuit 440 of the remote UE. At 804, a paging message comprising the remote UE ID of the remote UE is received from the eNodeB at the processing circuit 430 via the receive circuit 41 0, through the relay UE over a PC5 interface between the relay UE and the remote UE. In some embodiments, the paging message indicates the remote UE about an availability of a downlink (DL) data for the remote UE.

[0085] At 806, a connection request message comprising a cause value for paging is generated at the processing circuit 430, for subsequent transmission via the transmit circuit 420 to the relay UE over a PC5 interface between the remote UE and the relay UE, in response to receiving the paging message. In some embodiments, the connection set up message is configured to configure the relay UE to establish a PC5 direct connection between the remote UE and the relay UE, in order to receive the DL data through the relay UE. At 808, a service request procedure to establish an EPS bearer of the remote UE in the network through the relay UE is selectively initiated at the processing circuit 430, upon establishing the PC5 direct connection between the remote UE and the relay UE. In other embodiments, the service request procedure to establish the EPS bearer of the remote UE in the network is initiated by the relay UE. At 810, a downlink data signal comprising the DL data is received at the processing circuit 430 via the receive circuit 410, through the relay UE over the PC5 interface using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[0086] Fig. 9 illustrates a flowchart of a method 900 for a relay UE in a ProSe system comprising a remote UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. The method 900 is described herein with reference to the apparatus 500 in Fig. 5 and the ProSe system 200 in Fig. 2. In some embodiments, the apparatus 500 is included within the relay UE 212 of the ProSe system 200. At 902, a relay UE ID associated with the relay UE, a remote UE ID of the remote UE and a paired association ID indicating a paired association of the relay UE with the remote UE are stored at the memory circuit 540 of the relay UE. At 904, a connection request message comprising a cause value of paging is received at the processing circuit 530 via the receive circuit 510 from the remote UE, over a PC5 interface between the remote UE and the relay UE. In some embodiments, the cause value of paging indicates receipt of a paging message at the remote UE that indicates an availability of downlink (DL) data to the remote UE. In some embodiments, the connection request message is configured to configure the relay UE to establish a direct connection with the remote UE in order for the remote UE to receive the DL data associated with remote UE from the eNodeB through the relay UE.

[0087] At 906, a direct connection between the relay UE and the remote UE is established using the processing circuit 530, based on the connection request message. At 908, a service request procedure to establish an EPS bearer of the remote UE in the network is selectively initiated at the processing circuit 530, upon establishing the direct connection between the remote UE and the relay UE. In other embodiments, the service request procedure to establish the EPS bearer of the remote UE in the network is initiated by the remote UE. At 910, a downlink data signal comprising the DL data is received at the processing circuit 530 from an MME associated therewith and subsequently forwarded to the remote UE using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[0088] Fig. 1 0 illustrates a flowchart of a method 1000 for a relay UE in a ProSe system comprising a remote UE and an eNodeB associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. The method 1 000 is described herein with reference to the apparatus 500 in Fig. 5 and the ProSe system 300 in Fig. 3. In some embodiments, the apparatus 500 is included within the relay UE 312 of the ProSe system 300. At 1002, a relay UE ID associated with the relay UE, a remote UE ID of the remote UE and a paired association ID indicating a paired association of the relay UE with the remote UE are stored at the memory circuit 540 of the relay UE. At 1004, a paging message associated with the remote UE is transmitted from the processing circuit 530 of the relay UE via the transmit circuit 520 to the remote UE. In some embodiments, the paging message associated with the remote UE is received at the relay UE from the eNodeB.

[0089] At 1006, a connection request message comprising a cause value of paging is received at the processing circuit 530 via the receive circuit 510 from the remote UE, over a PC5 interface between the remote UE and the relay UE, in response to transmitting the paging message. In some embodiments, the cause value of paging indicates the receipt of the paging message at the remote UE that indicates an availability of downlink (DL) data to the remote UE. In some embodiments, the connection request message is configured to configure the relay UE to establish a direct connection with the remote UE in order for the remote UE to receive the DL data associated with remote UE from the eNodeB through the relay UE. At 1008, a direct connection between the relay UE and the remote UE is established using the

processing circuit 530, based on the connection request message. At 101 0, a service request procedure to establish an EPS bearer of the remote UE in the network is selectively initiated at the processing circuit 530 of the relay UE, upon establishing the direct connection between the remote UE and the relay UE. In other embodiments, the service request procedure to establish the EPS bearer of the remote UE in the network is initiated by the remote UE. At 1012, a downlink data signal comprising the DL data is received at the processing circuit 530 and subsequently forwarded to the remote UE using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[0090] Fig. 1 1 illustrates a flowchart of a method 1 1 00 for an eNodeB in a ProSe system comprising a remote UE and a relay UE associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. The method 1 100 is described herein with reference to the apparatus 600 in Fig. 6 and the ProSe system 200 in Fig. 2. In some embodiments, the apparatus 600 is included within the eNodeB 214 of the ProSe system 200. At 1 102, a relay UE ID associated with the relay UE and a remote UE ID of the remote UE (both obtained at the initial attach) are stored in the memory circuit 640 of the eNodeB. At 1 104, a paging message associated with the remote UE is transmitted from the processing circuit 630 of the eNodeB via the transmit circuit 610, directly to the remote UE over an air interface between the eNodeB and the remote UE. In some embodiments, the paging message associated with the remote UE is received at the eNodeB from an MME associated therewith. In some embodiments, the paging message indicates the availability of downlink (DL) data for the remote UE.

[0091] At 1 106, a sidelink UE information message is received from the relay UE at the processing circuit 630 via the receive circuit 620, in response to transmitting the paging message to the remote UE. In some embodiments, the sidelink UE information message comprises the remote UE ID and indicates a receipt of the paging message at the remote UE or an establishment of a connection between the remote UE and the relay UE or both. At 1 108, one or more messages associated with a service request procedure to establish an EPS bearer of the remote UE in the network for L2 relaying is received at the processing circuit 630 via the receive circuit 620. At 1 1 10, an S1 -AP message is generated at the processing circuit 630, for subsequent transmission to an MME associated therewith using the transmit circuit 610, upon receiving the sidelink UE information message. In some embodiments, the S1 -AP message comprises the remote UE ID and the EPS bearer ID of the remote UE or the relay UE, in order to enable the MME to forward DL data from the S-GW, using the EPS bearer of the remote UE during L2 relaying or using an EPS bearer of the relay UE during L3 relaying. At 1 1 12, the DL data associated with the remote UE is forwarded from an S-gateway (S- GW) associated with the eNodeB to the relay UE by the processing circuit 630, using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[0092] Fig. 1 2 illustrates a flowchart of a method 1200 for an eNodeB in a ProSe system comprising a remote UE and a relay UE associated therewith, that facilitates downlink reachability of the remote UE, according to one embodiment of the disclosure. The method 1 200 is described herein with reference to the apparatus 600 in Fig. 6 and the ProSe system 300 in Fig. 3. In some embodiments, the apparatus 600 is included within the eNodeB 314 of the ProSe system 300. At 1202, a relay UE ID associated with the relay UE and a remote UE ID of the remote UE (both obtained at the initial attach) are stored in the memory circuit 640 of the eNodeB. At 1204, a paging message associated with the remote UE is transmitted from the processing circuit 630 of the eNodeB via the transmit circuit 610, to the relay UE for subsequent transmission to the remote UE. In some embodiments, the paging message associated with the remote UE is received at the eNodeB from an MME associated therewith. In some embodiments, the paging message indicates the availability of downlink (DL) data for the remote UE.

[0093] At 1206, a sidelink UE information message is received from the relay UE at the processing circuit 630 via the receive circuit 620, in response to transmitting the paging message to the relay UE. In some embodiments, the sidelink UE information message comprises the remote UE ID and indicates a receipt of the paging message at the remote UE or an establishment of a connection between the remote UE and the relay UE or both. At 1208, one or more messages associated with a service request procedure to establish an EPS bearer of the remote UE in the network for L2 relaying is received at the processing circuit 630 of the eNodeB via the receive circuit 620. At 1210, an S1 -AP message is generated at the processing circuit 630, for subsequent transmission to an MME associated therewith using the transmit circuit 610, upon receiving the sidelink UE information message. In some embodiments, the S1 -AP message comprises the remote UE ID and the EPS bearer ID of the remote UE or the relay UE, in order to enable the MME to forward DL data from the S-GW, using the EPS bearer of the remote UE during L2 relaying or using an EPS bearer of the relay UE during L3 relaying. At 1212, the DL data associated with the remote UE is forwarded from an S-gateway (S-GW) associated with the eNodeB to the relay UE by the processing circuit 630, using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[0094] While the methods are illustrated and described above as a series of acts or events, it will be appreciated that the illustrated ordering of such acts or events are not to be interpreted in a limiting sense. For example, some acts may occur in different orders and/or concurrently with other acts or events apart from those illustrated and/or described herein. In addition, not all illustrated acts may be required to implement one or more aspects or embodiments of the disclosure herein. Also, one or more of the acts depicted herein may be carried out in one or more separate acts and/or phases.

[0095] Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. Fig. 13 illustrates, for one embodiment, example components of a User Equipment (UE) device 1300. In some embodiments, the UE device 1300 may include application circuitry 1302, baseband circuitry 1 304, Radio Frequency (RF) circuitry 1306, front-end module (FEM) circuitry 1308 and one or more antennas 1310, coupled together at least as shown.

[0096] The application circuitry 1302 may include one or more application processing circuits. For example, the application circuitry 1302 may include circuitry such as, but not limited to, one or more single-core or multi-core processing circuits. The processing circuit(s) may include any combination of general-purpose processing circuits and dedicated processing circuits (e.g., graphics processing circuits,

application processing circuits, etc.). The processing circuits may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0097] The baseband circuitry 1304 may include circuitry such as, but not limited to, one or more single-core or multi-core processing circuits. The baseband circuitry 1304 may include one or more baseband processing circuits and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 1306 and to generate baseband signals for a transmit signal path of the RF circuitry 1306. Baseband processing circuity 1304 may interface with the application circuitry 1302 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 1306. For example, in some embodiments, the baseband circuitry 1304 may include a second generation (2G) baseband processing circuit 1304a, third generation (3G) baseband processing circuit 1304b, fourth generation (4G) baseband processing circuit 1304c, and/or other baseband processing circuit(s) 1304d for other existing

generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 1304 (e.g., one or more of baseband processing circuits 1304a-d) may handle various radio control functions that

enable communication with one or more radio networks via the RF circuitry 1306. The radio control functions may include, but are not limited to, signal

modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 1 304 may include Fast-Fourier Transform (FFT), precoding, and/or constellation

mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 1304 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality.

Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0098] In some embodiments, the baseband circuitry 1304 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 1304e of the baseband circuitry 1304 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processing circuit(s) (DSP) 1304f. The audio DSP(s) 1304f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 1304 and the application circuitry 1302 may be implemented together such as, for example, on a system on a chip (SOC).

[0099] In some embodiments, the baseband circuitry 1304 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 1304 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 1304 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[00100] RF circuitry 1306 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 1306 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 1306 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 1308 and provide baseband signals to the baseband circuitry 1304. RF circuitry 1306 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 1304 and provide RF output signals to the FEM circuitry 1308 for transmission.

[00101 ] In some embodiments, the RF circuitry 1306 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 1306 may include mixer circuitry 1 306a, amplifier circuitry 1306b and filter circuitry 1306c. The transmit signal path of the RF circuitry 1306 may include filter circuitry 1306c and mixer circuitry 1306a. RF circuitry 1306 may also include synthesizer circuitry 1306d for synthesizing a frequency for use by the mixer circuitry 1306a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 1306a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 1308 based on the synthesized frequency provided by synthesizer circuitry 1306d. The amplifier circuitry 1306b may be configured to amplify the down-converted signals and the filter circuitry 1 306c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 1304 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 1306a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[00102] In some embodiments, the mixer circuitry 1306a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 1306d to generate RF output signals for the FEM circuitry 1308. The baseband signals may be provided by the baseband circuitry 1304 and may be filtered by filter circuitry 1306c. The filter circuitry 1306c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[00103] In some embodiments, the mixer circuitry 1306a of the receive signal path and the mixer circuitry 1306a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 1306a of the receive signal path and the mixer circuitry 1306a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 1 306a of the receive signal path and the mixer circuitry 1306a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 1306a of the receive signal path and the mixer circuitry 1306a of the transmit signal path may be configured for super-heterodyne operation.

[00104] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 1306 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 1304 may include a digital baseband interface to communicate with the RF circuitry 1306.

[00105] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the

embodiments is not limited in this respect.

[00106] In some embodiments, the synthesizer circuitry 1306d may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 1306d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[00107] The synthesizer circuitry 1306d may be configured to synthesize an output frequency for use by the mixer circuitry 1306a of the RF circuitry 1306 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 1306d may be a fractional N/N+1 synthesizer.

[00108] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 1304 or the applications processing circuit 1302 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processing circuit 1302.

[00109] Synthesizer circuitry 1 306d of the RF circuitry 1 306 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip- flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[00110] In some embodiments, synthesizer circuitry 1 306d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 1306 may include an IQ/polar converter.

[00111 ] FEM circuitry 1308 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 1310, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 1306 for further processing. FEM circuitry 1308 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 1306 for transmission by one or more of the one or more antennas 1310.

[00112] In some embodiments, the FEM circuitry 1308 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 1306). The transmit signal path of the FEM circuitry 1308 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 1306), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 1310.

[00113] In some embodiments, the UE device 1300 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface. [00114] While the apparatus has been illustrated and described with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular regard to the various functions performed by the above described

components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a "means") used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the invention.

[00115] Examples can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including instructions that, when performed by a machine cause the machine to perform acts of the method or of an apparatus or system for concurrent communication using multiple communication technologies according to embodiments and examples described herein.

[00116] Example 1 is an apparatus for use in a remote user equipment (UE) of a Proximty-Based Services (ProSe) network, comprising a processing circuit that, upon execution of instructions from a memory circuit is configured to detect a paging message comprising a remote UE ID of the remote UE from an eNodeB of the ProSe network, over an air interface between the eNodeB and the remote UE, or through a relay UE of the ProSe network over a PC5 interface between the relay UE and the remote UE, wherein the paging message informs the remote UE about an availability of a downlink (DL) data for the remote UE; generate a connection request message comprising a cause value for paging, for subsequent transmission to the relay UE over the PC5 interface, in response to receiving the paging message, in order to establish a direct connection between the remote UE and the relay UE to receive the DL data through the relay UE; and detect a downlink data signal comprising the DL data from the eNodeB through the relay UE over the PC5 interface, in response to transmitting the connection request message.

[00117] Example 2 is an apparatus including the subject matter of example 1 , wherein the processing circuit is further configured to initiate a service request procedure to establish an evolved packet system (EPS) bearer of the remote UE in the network through the relay UE, upon establishing the direct connection between the remote UE and the relay UE.

[00118] Example 3 is an apparatus including the subject matter of examples 1 -2, including or omitting elements, wherein initiating the service request procedure comprises providing one or more messages associated with the service request procedure over the PC5 interface to the relay UE, wherein the one or more messages are subsequently forwarded by the relay UE transparently to the eNodeB.

[00119] Example 4 is an apparatus including the subject matter of examples 1 -3, including or omitting elements, wherein the downlink data signal is detected using the EPS bearer of the remote UE during L2 relaying and wherein the downlink data signal is received using an EPS bearer of the relay UE during L3 relaying.

[00120] Example 5 is an apparatus including the subject matter of examples 1 -4, including or omitting elements, wherein the processing circuit is further configured to monitor a periodic discovery message from the relay UE, in order to receive the paging message through the relay UE.

[00121 ] Example 6 is an apparatus including the subject matter of examples 1 -5, including or omitting elements, wherein the processing circuit is further configured to monitor one or more discovery resource elements of a pre-configured resource pattern of the relay UE, in order to receive the paging message through the relay UE.

[00122] Example 7 is an apparatus including the subject matter of examples 1 -6, including or omitting elements, wherein the processing circuit is further configured to periodically monitor a sidelink paging control channel over the PC5 interface defined for conveying downlink paging information and system information, in order to receive the paging message through the relay UE.

[00123] Example 8 is an apparatus including the subject matter of examples 1 -7, including or omitting elements, wherein the processing circuit is configured to generate a PC5 direct communication request message for subsequent transmission to the relay UE prior to receiving the paging message through the relay UE, wherein the PC5 direct communication request message comprises the remote UE ID and a paired paging request in order to establish a paired paging between the remote UE and the relay UE.

[00124] Example 9 is an apparatus including the subject matter of examples 1 -8, including or omitting elements, wherein the processing circuit is further configured to generate a paired paging indication message for subsequent transmission to the eNodeB, upon establishing the paired paging between the remote UE and the relay UE, wherein the paired paging indication message comprises an indication of the paired paging between the remote UE and the relay UE, the remote UE ID, a paired

association ID indicating a paired association of the remote UE with the relay UE and an indication whether the UE transmitting the paired paging indication message is the relay UE or the remote UE.

[00125] Example 10 is an apparatus for use in a relay user equipment (UE) of a ProSe network, comprising a memory circuit configured to store a relay UE ID associated with the relay UE, a remote UE ID of a remote UE of the ProSe network and a paired association ID indicating a paired association of the relay UE with the remote UE; a processing circuit configured to detect a connection request message comprising a cause value of paging from the remote UE, over a PC5 interface between the remote UE and the relay UE, wherein the cause value of paging indicates receipt of a paging message indicating an availability of downlink (DL) data to the remote UE, at the remote UE from an eNodeB of the ProSe network over an air interface or through the relay UE; establish a direct connection between the relay UE and the remote UE, upon receiving the connection request message; and receive a downlink data signal comprising the DL data from an S-gateway (S-GW) associated with the eNodeB using an evolved packet system (EPS) bearer of the remote UE or the relay UE, for subsequent transmission to the remote UE, over the PC5 interface, upon establishing the direct connection between the relay UE and the remote UE.

[00126] Example 1 1 is an apparatus including the subject matter of examples 10, wherein the processing circuit is further configured to generate a sidelink UE information message comprising the remote UE ID of the remote UE, for subsequent transmission to the eNodeB, prior to detecting the downlink data signal, in order to enable the remote UE to be visible to the eNodeB and an MME associated therewith for DL data transfer. [00127] Example 12 is an apparatus including the subject matter of examples 10-1 1 , including or omitting elements, wherein the processing circuit is further configured to establish the EPS bearer of the remote UE in the network, upon establishing the direct connection between the relay UE and the remote UE, in order to detect the downlink data signal during L2 relaying.

[00128] Example 13 is an apparatus including the subject matter of examples 10-1 2, including or omitting elements, wherein the processing circuit is further configured to establish the EPS bearer of the remote UE by performing a service request procedure on behalf of the remote UE based on providing the relay UE ID, an EPS bearer ID of the remote UE and the pair association id, to the eNodeB.

[00129] Example 14 is an apparatus including the subject matter of examples 10-1 3, including or omitting elements, wherein the processing circuit is further configured to establish the EPS bearer of the remote UE by forwarding one or more messages associated with a service request procedure of the remote UE received from the remote UE over the PC5 interface, to the eNodeB.

[00130] Example 15 is an apparatus including the subject matter of examples 10-14, including or omitting elements, wherein the processing circuit is configured to detect the paging message associated with the remote UE from the eNodeB for subsequent transmission to the remote UE, prior to detecting the connection request message from the remote UE, based on a paired paging association of the remote UE and the relay UE.

[00131 ] Example 16 is an apparatus including the subject matter of examples 10-1 5, including or omitting elements, wherein the processing circuit is further configured to detect a PC5 direct communication request message from the remote UE over the PC5 interface prior to transmitting the paging message to the remote UE, wherein the PC5 direct communication request message comprises the remote UE ID and a paired paging request in order to establish the paired paging between the remote UE and the relay UE.

[00132] Example 17 is an apparatus including the subject matter of examples 10-1 6, including or omitting elements, wherein the processing circuit is further configured to generate a paired paging indication message for subsequent transmission to the eNodeB to inform the eNodeB on the paired paging, upon establishing the paired paging between the remote UE and the relay UE, wherein the paired paging indication message comprises an indication of the paired paging between the remote UE and the relay UE, the relay UE ID, the paired association ID and an indication whether the UE transmitting the paired paging indication message is the relay UE or the remote UE.

[00133] Example 18 is an apparatus including the subject matter of examples 10-1 7, including or omitting elements, wherein the paging message associated with the remote UE is detected at the processing circuit from the eNodeB based on monitoring a paging occasion of the remote UE or a paging occasion of the relay UE.

[00134] Example 19 is an apparatus including the subject matter of examples 10-1 8, including or omitting elements, wherein the paging message associated with the remote UE is generated by the processing circuit for provision to the remote UE, using periodic discovery announcement message.

[00135] Example 20 is an apparatus including the subject matter of examples 10-1 9, including or omitting elements, wherein the paging message associated with the remote UE is generated by the processing circuit for provision to the remote UE, using one or more discovery resource elements of a pre-configured resource pattern that the remote UE is monitoring.

[00136] Example 21 is an apparatus including the subject matter of examples 10-20, including or omitting elements, wherein the paging message associated with the remote UE is generated by the processing circuit for provision to the remote UE, using a sidelink paging control channel over the PC5 interface defined for conveying downlink paging information and system information.

[00137] Example 22 is an apparatus including the subject matter of examples 10-21 , including or omitting elements, wherein the processing circuit is further configured to buffer the DL data for a predetermined period of time, upon a release of the direct connection between the remote UE and the relay UE.

[00138] Example 23 is an apparatus for use in an eNodeB of a ProSe network, comprising a memory circuit configured to store a relay user equipment (UE) ID associated with a relay UE and a remote UE ID of a remote UE; a processing circuit configured to provide a paging message associated with the remote UE received from a mobility management entity (MME) associated therewith, to the remote UE over an air interface between the eNodeB and the remote UE, or through the relay UE for subsequent transmission to the remote UE over a PC5 interface between the relay UE and the remote UE, wherein the paging message indicates the availability of downlink (DL) data for the remote UE; detect a sidelink UE information message from the relay UE, wherein the sidelink UE information message indicates a receipt of the paging message at the remote UE or an establishment of a direct connection between the remote UE and the relay UE or both, in response to providing the paging message; and provide the DL data associated with the remote UE received from an S-gateway (S-GW) associated therewith, to the relay UE for subsequent transmission to the remote UE, using an evolved packet system (EPS) bearer of the remote UE or an EPS bearer of the relay UE, when the sidelink UE information message indicates an establishment of the direct connection between the remote UE and the relay UE.

[00139] Example 24 is an apparatus including the subject matter of example 23, wherein the processing circuit is further configured to detect one or more messages associated with a service request procedure to establish the EPS bearer of the remote UE in the network for L2 relaying, prior to forwarding the DL data, wherein the one or more messages comprises an EPS bearer ID associated with the remote UE.

[00140] Example 25 is an apparatus including the subject matter of examples 23-24, including or omitting elements, wherein the processing circuit is further configured to generate an S1 application protocol (S1 -AP) message, for subsequent transmission to an MME associated therewith using the transmit circuit, upon detecting the sidelink UE information message, wherein the S1 -AP message comprises the remote UE ID and the EPS bearer ID of the remote UE or the relay UE, in order to enable the MME to forward DL data from the S-GW, using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

[00141 ] Example 26 is an apparatus including the subject matter of examples 23-25, including or omitting elements, wherein the processing circuit is configured to provide the paging message to the remote UE through the relay UE, based on a paired paging association between the relay UE and the remote UE. [00142] Example 27 is an apparatus including the subject matter of examples 23-26, including or omitting elements, wherein the processing circuit is further configured to detect a paired paging indication message from the relay UE or the remote UE, prior to providing the paging message to the remote UE, wherein the paired paging indication message comprises an indication of an establishment or release of a paired paging between the remote UE and the relay UE, relay UE ID or the remote UE ID based on the UE transmitting the paired paging indication message, a paired association ID and an indication whether the UE transmitting the paired paging indication message is the relay UE or the remote UE.

[00143] Example 28 is an apparatus including the subject matter of examples 23-27, including or omitting elements, wherein the processing circuit is configured to provide the paging message of both the relay UE and the remote UE at a paging occasion of the relay UE, wherein the paging occasion of the relay UE is determined based on the relay UE ID.

[00144] Example 29 is an apparatus including the subject matter of examples 23-28, including or omitting elements, wherein the processing circuit is configured to provide the paging message of the remote UE at the paging occasion of the remote UE, wherein the paging occasion of the remote UE is determined based on the remote UE ID.

[00145] Example 30 is an apparatus including the subject matter of examples 23-29, including or omitting elements, wherein the sidelink UE information message further comprises information on a release of a direct connection between the relay UE and the remote UE and the processing circuit is configured to buffer the DL data to be forwarded to the remote UE, when the sidelink UE information message indicates the release of the direct connection between the remote UE and the relay UE.

[00146] Various illustrative logics, logical blocks, modules, and circuits described in connection with aspects disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other

programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform functions described herein. A general-purpose processor can be a microprocessor, but, in the alternative, processor can be any conventional processor, controller, microcontroller, or state machine.

[00147] The above description of illustrated embodiments of the subject disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the disclosed embodiments to the precise forms disclosed. While specific embodiments and examples are described herein for illustrative purposes, various modifications are possible that are considered within the scope of such embodiments and examples, as those skilled in the relevant art can recognize.

[00148] In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding Figures, where applicable, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same, similar, alternative, or substitute function of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims below.

[00149] In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a "means") used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

Claims

1 . An apparatus for use in a remote user equipment (UE), of a Proximity-Based Services (ProSe) network, comprising:

a processing circuit that, upon execution of instructions from a memory circuit is configured to:

detect a paging message comprising a remote UE ID of the remote UE from an eNodeB of the ProSe network, over an air interface between the eNodeB and the remote UE, or through a relay UE of the ProSe network over a PC5 interface between the relay UE and the remote UE, wherein the paging message informs the remote UE about an availability of a downlink (DL) data for the remote UE;

generate a connection request message comprising a cause value for paging, for subsequent transmission to the relay UE over the PC5 interface, in response to receiving the paging message, in order to establish a direct connection between the remote UE and the relay UE to receive the DL data through the relay UE; and

detect a downlink data signal comprising the DL data from the eNodeB through the relay UE over the PC5 interface, in response to transmitting the connection request message.

2. The apparatus of claim 1 , wherein the processing circuit is further configured to initiate a service request procedure to establish an evolved packet system (EPS) bearer of the remote UE in the network through the relay UE, upon establishing the direct connection between the remote UE and the relay UE.

3. The apparatus of claim 2, wherein initiating the service request procedure comprises providing one or more messages associated with the service request procedure over the PC5 interface to the relay UE, wherein the one or more messages are subsequently forwarded by the relay UE transparently to the eNodeB.

4. The apparatus of any of the claims 2-3, wherein the downlink data signal is detected using the EPS bearer of the remote UE during L2 relaying and wherein the downlink data signal is received using an EPS bearer of the relay UE during L3 relaying.

5. The apparatus of any of the claims 1 -3, wherein the processing circuit is configured to generate a PC5 direct communication request message for subsequent transmission to the relay UE prior to detecting the paging message through the relay UE, wherein the PC5 direct communication request message comprises the remote UE ID and a paired paging request in order to establish a paired paging between the remote UE and the relay UE.

6. The apparatus of claim 5, wherein the processing circuit is further configured to generate a paired paging indication message for subsequent transmission to the eNodeB, upon establishing the paired paging between the remote UE and the relay UE, wherein the paired paging indication message comprises an indication of the paired paging between the remote UE and the relay UE, the remote UE ID, a paired

7. An apparatus for use in a relay user equipment (UE) of a ProSe network, comprising:

a memory circuit configured to store a relay UE ID associated with the relay UE, a remote UE ID of a remote UE and a paired association ID indicating a paired association of the relay UE with the remote UE;

a processing circuit configured to:

detect a connection request message comprising a cause value of paging from the remote UE, over a PC5 interface between the remote UE and the relay UE, wherein the cause value of paging indicates receipt of a paging message indicating an availability of downlink (DL) data to the remote UE, at the remote UE from an eNodeB over an air interface or through the relay UE;

establish a direct connection between the relay UE and the remote UE, upon receiving the connection request message; and

detect a downlink data signal comprising the DL data from an S-gateway (S-GW) associated with the eNodeB using an evolved packet system (EPS) bearer of the remote UE or the relay UE, for subsequent transmission to the remote UE, over the PC5 interface, upon establishing the direct connection between the relay UE and the remote UE.

8. The apparatus of claim 7, wherein the processing circuit is further configured to generate a sidelink UE information message comprising the remote UE ID of the remote UE, for subsequent transmission to the eNodeB, prior to detecting the downlink data signal, in order to enable the remote UE to be visible to the eNodeB and an MME associated therewith for DL data transfer.

9. The apparatus of any of the claims 7-8, wherein the processing circuit is further configured to establish the EPS bearer of the remote UE in the network, upon establishing the direct connection between the relay UE and the remote UE, in order to detect the downlink data signal during L2 relaying.

10. The apparatus of claim 9, wherein the processing circuit is further configured to establish the EPS bearer of the remote UE by performing a service request procedure on behalf of the remote UE based on providing the relay UE ID, an EPS bearer ID of the remote UE and the pair association id, to the eNodeB.

1 1 . The apparatus of claim 7, wherein the processing circuit is configured to detect the paging message associated with the remote UE from the eNodeB for subsequent transmission to the remote UE, prior to detecting the connection request message from the remote UE, based on a paired paging association of the remote UE and the relay UE.

12. The apparatus of claim 1 1 , wherein the processing circuit is further configured to detect a PC5 direct communication request message from the remote UE over the PC5 interface prior to transmitting the paging message to the remote UE, wherein the PC5 direct communication request message comprises the remote UE ID and a paired paging request in order to establish the paired paging between the remote UE and the relay UE.

13. The apparatus of claim 12, wherein the processing circuit is further configured to generate a paired paging indication message for subsequent transmission to the eNodeB to inform the eNodeB on the paired paging, upon establishing the paired paging between the remote UE and the relay UE, wherein the paired paging indication message comprises an indication of the paired paging between the remote UE and the relay UE, the relay UE ID, the paired association ID and an indication whether the UE transmitting the paired paging indication message is the relay UE or the remote UE.

14. The apparatus of any of the claims 1 1 -13, wherein the paging message associated with the remote UE is detected at the processing circuit from the eNodeB based on monitoring a paging occasion of the remote UE or a paging occasion of the relay UE.

15. The apparatus of any of the claims 1 1 -13, wherein the paging message associated with the remote UE is generated by the processing circuit for provision to the remote UE, using periodic discovery announcement message.

16. The apparatus of any of the claims 1 1 -13, wherein the paging message associated with the remote UE is generated by the processing circuit for provision to the remote UE, using one or more discovery resource elements of a pre-configured resource pattern that the remote UE is monitoring.

17. The apparatus of any of the claims 1 1 -13, wherein the paging message associated with the remote UE is generated by the processing circuit for provision to the remote UE, using a sidelink paging control channel over the PC5 interface defined for conveying downlink paging information and system information.

18. The apparatus of any of the claims 7-8, wherein the processing circuit is further configured to buffer the DL data for a predetermined period of time, upon a release of the direct connection between the remote UE and the relay UE.

19. An apparatus for use in an eNodeB of a ProSe network, comprising:

a memory circuit configured to store a relay user equipment (UE) ID associated with a relay UE and a remote UE ID of a remote UE;

a processing circuit configured to: provide a paging message associated with the remote UE received from a mobility management entity (MME) associated therewith, to the remote UE over an air interface between the eNodeB and the remote UE, or through the relay UE for subsequent transmission to the remote UE over a PC5 interface between the relay UE and the remote UE, wherein the paging message indicates availability of downlink (DL) data for the remote UE;

detect a sidelink UE information message from the relay UE, wherein the sidelink UE information message indicates a receipt of the paging message at the remote UE or an establishment of a direct connection between the remote UE and the relay UE or both, in response to providing the paging message; and provide the DL data associated with the remote UE received from an S- gateway (S-GW) associated therewith, to the relay UE for subsequent transmission to the remote UE, using an evolved packet system (EPS) bearer of the remote UE or an EPS bearer of the relay UE, when the sidelink UE information message indicates the establishment of the direct connection between the remote UE and the relay UE.

20. The apparatus of claim 19, wherein the processing circuit is further configured to detect one or more messages associated with a service request procedure to establish the EPS bearer of the remote UE in the network for L2 relaying, prior to forwarding the DL data, wherein the one or more messages comprises an EPS bearer ID associated with the remote UE.

21 . The apparatus of claim 20, wherein the processing circuit is further configured to generate a S1 application protocol (S1 -AP) message, for subsequent transmission to an MME associated therewith, upon receiving the sidelink UE information message, wherein the S1 -AP message comprises the remote UE ID and the EPS bearer ID of the remote UE or the relay UE, in order to enable the MME to forward DL data from the S- GW, using the EPS bearer of the remote UE during L2 relaying or using the EPS bearer of the relay UE during L3 relaying.

22. The apparatus of any of the claims 19-20, wherein the processing circuit is configured to provide the paging message to the remote UE through the relay UE, based on a paired paging association between the relay UE and the remote UE.

23. The apparatus of claim 22, wherein the processing circuit is configured to provide the paging message of both the relay UE and the remote UE at a paging occasion of the relay UE, wherein the paging occasion of the relay UE is determined based on the relay UE ID.

24. The apparatus of claim 22, wherein the processing circuit is configured to provide the paging message of the remote UE at a paging occasion of the remote UE, wherein the paging occasion of the remote UE is determined based on the remote UE ID.

25. The apparatus of any of the claims 19-21 , wherein the sidelink UE information message further comprises information on a release of the direct connection between the relay UE and the remote UE and the processing circuit is configured to buffer the DL data to be forwarded to the remote UE, when the sidelink UE information message indicates the release of the direct connection between the remote UE and the relay UE.