WO2019192011A1

WO2019192011A1 - Backup configuration in random access procedure

Info

Publication number: WO2019192011A1
Application number: PCT/CN2018/082070
Authority: WO
Inventors: Haitao Li; Rapeepat Ratasuk
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2018-04-05
Filing date: 2018-04-05
Publication date: 2019-10-10
Also published as: CN111937478A; CN111937478B

Abstract

Embodiments of the present disclosure relate to a method, device and computer readable storage media for a backup configuration in a random access (RA) procedure. In example embodiments, a terminal device is configured with a first coverage enhancement (CE) mode. The terminal device initiates a RA procedure in a second CE mode different from the first CE mode. During the random access procedure, the terminal device determines whether a dedicated backup configuration is enabled. If it is determined that the dedicated backup configuration is enabled, the terminal device detects a message from a network device by using the dedicated backup configuration such that the RA procedure is more effective and efficient.

Description

BACKUP CONFIGURATION IN RANDOM ACCESS PROCEDURE

FIELD

Embodiments of the present disclosure generally relate to the field of communications, and in particular, to a method, device and computer readable storage media for a backup configuration in a random access (RA) procedure.

BACKGROUND

In the 3rd Generation Partnership Project (3GPP) specification, coverage enhancement (CE) levels have been proposed for user equipment (UE) in a random access (RA) procedure to enable enhanced coverage. For example, four CE levels are specified for different coverage. The UE may select a CE level from the four CE levels based on Reference Signal Receiving Power (RSRP) measurements of a serving cell and broadcasted RSRP thresholds for these CE levels. If a RA attempt in the selected CE level has failed for several times, the UE may increase the CE level and initiate a further RA attempt in the increased CE level until the allowed maximum attempt number is reached.

For RRC_CONNECTED UEs in a Radio Resource Control (RRC) connected state, two CE modes are proposed, which are referred to as CE Mode A and CE Mode B, respectively. The CE Mode A corresponds to CE level 0 and CE level 1 and specifies a set of behaviors with no repetitions or a small number of repetitions. The CE Mode B corresponds to CE level 2 and CE level 3 and specifies a further set of behaviors with a large number of repetitions. The specific CE mode may be explicitly configured to a UE via dedicated RRC signaling.

During the RA procedure of the RRC_CONNECTED UE, the UE may also increase the CE level after the RA attempt in the lower CE level failed. The increasing of the CE level may span different CE modes. For example, if the RA attempt in the CE mode A failed, the UE may switch to the

CE level

2 or 3 for the CE mode B to initiate a further RA attempt.

SUMMARY

In general, example embodiments of the present disclosure provide a method, device and computer readable storage media for a backup configuration in a RA procedure.

In a first aspect, a method at a terminal device is provided. The terminal device is configured with a first CE mode. The terminal device initiates a random access procedure in a second CE mode different from the first CE mode. During the random access procedure, the terminal device determines whether a dedicated backup configuration is enabled. If it is determined that the dedicated backup configuration is enabled, the terminal device detects a message from a network device by using the dedicated backup configuration.

In a second aspect, there is provided a device comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the device to:initiate a random access procedure in a second CE mode different from a first CE mode that is configured; and during the random access procedure, determine whether a dedicated backup configuration is enabled, and in response to determining that the dedicated backup configuration is enabled, detect a message from a network device by using the dedicated backup configuration.

In a third aspect, there is provided a computer readable storage medium that stores a computer program thereon. The computer program, when executed by a processor, causes the processor to carry out the method according to the first aspect.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

FIG. 1 illustrates an example interaction process between a terminal device and a network device in a conventional RA procedure;

FIG. 2 illustrates an example communication network in which embodiments of the present disclosure can be implemented;

FIG. 3 illustrates a flowchart of an example method in accordance with some embodiments of the present disclosure; and

FIG. 4 illustrates a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

As used herein, the term “communication network” refers to a network that follows any suitable communication standards or protocols such as long term evolution (LTE) , LTE-Advanced (LTE-A) and 5G NR, and employs any suitable communication technologies, including, for example, Multiple-Input Multiple-Output (MIMO) , OFDM, time division multiplexing (TDM) , frequency division multiplexing (FDM) , code division multiplexing (CDM) , Bluetooth, ZigBee, machine type communication (MTC) , eMBB, mMTC and uRLLC technologies.

As used herein, the term “network device” refers to any suitable device at a network side of a communication network. The network device may include any suitable device in an access network of the communication network, for example, including a base station (BS) , a relay, an access point (AP) , a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a gigabit NodeB (gNB) , a Remote Radio Module (RRU) , a radio header (RH) , a remote radio head (RRH) , a low power node such as a femto, a pico, and the like. For the purpose of discussion, in some embodiments, the eNB is taken as an example of the network device.

As used herein, the term “terminal device” refers to a device capable of, configured for, arranged for, and/or operable for communications with a network device or a further terminal device in a communication network. The communications may involve transmitting and/or receiving wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for conveying information over air. In some embodiments, the terminal device may be configured to transmit and/or receive information without direct human interaction. For example, the terminal device may transmit information to the network device on predetermined schedules, when triggered by an internal or external event, or in response to requests from the network side.

Examples of the terminal device include, but are not limited to, user equipment (UE) such as smart phones, wireless-enabled tablet computers, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , and/or wireless customer-premises equipment (CPE) . For the purpose of discussion, in the following, some embodiments will be described with reference to UEs as examples of the terminal devices, and the terms “terminal device” and “user equipment” (UE) may be used interchangeably in the context of the present disclosure.

As used herein, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) : (i) a combination of analog and/or digital hardware circuit (s) with software/firmware and (ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the singular forms “a” , “an” , and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to” . The term “based on” is to be read as “based at least in part on” . The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment” . The term “another embodiment” is to be read as “at least one other embodiment” . Other definitions, explicit and implicit, may be included below.

As described above, two CE modes, namely, CE Mode A and CE Mode B, have been proposed for the RRC_CONNECTED UEs. The UE may use one or more of the CE levels corresponding to the two CE modes during the RA procedure. For example, an enhanced machine-type communication (eMTC) UE may attempt RA in several CE levels during a Radio Access Channel (RACH) procedure. If the UE is configured with the CE mode A, the UE may initiate the RACH procedure, for example, in the CE mode A after the maximum scheduling request number (SR-MAX) is reached. When the UE fails RA in the CE mode A, the UE may select the

CE level

2 or 3 corresponding to the CE mode B, to send a further RA preamble.

Conventionally, during the RACH procedure, the UE may use common configurations for the selected CE level, such as a common search space (CSS) for a machine-type communication physical downlink control channel (MPDCCH) search space. For the purpose of contention resolution, after message 3 (Msg3) is successfully transmitted to the eNB, the UE which was configured with CE mode A falls back to the dedicated configurations for the CE mode A, such as a user-specific search space (USS) for the MPDCCH search space, for further communication.

FIG. 1 illustrates an example interactive process 100 between the UE and the eNB in a conventional RA procedure. In this example, the UE is configured with the CE mode A. After the RA attempt with the CE mode A has failed, the UE selects the

CE level

2 or 3 corresponding to the CE mode B. Then, in the selected

CE level

2 or 3, as shown, the UE sends (105) message 1 (Msgl) containing a RA preamble to the eNB, and then the eNB sends (110) message 2 (Msg2) as a random access response (RAR) . Upon the reception of Msg2, the UE sends (115) message 3 (Msg3) with Cell Radio Network Temporary Identifier (C-RNTI) .

In this example, the transmission of Msg3 is failed. The UE performs the retransmission of Msg3 (120) . During the retransmission of Msg3 (120) , the eNB sends (120a) an uplink (UL) grant scrambled by a temporary C-RNTI. The UE may use the CSS for the CE mode B to detect the UL grant. Upon the reception of the UL grant, the UE sends (120b) Msg3 to the eNB. Upon the success of the Msg3 transmission or retransmission, the eNB sends (125) an UL grant scrambled by the C-RNTI in the MPDCCH. At this time, the UE falls back to the CE mode A and use the dedicated configurations for the CE mode A to detect the UL grant. Then, the UE initiates (130) transmission on Physical Uplink Shared Channel (PUSCH) based on the UL grant.

The inventor finds that different CE modes typically have different configurations, such as the maximum repetition number (R-max) for MPDCCH/PUCCH/PUSCH/Physical Downlink Shared Channel (PDSCH) . The CE mode-A specific configurations sometimes are not robust for transmissions in the CE mode B. For example, in the RA procedure as shown in FIG. 1, using the dedicated configurations for the CE mode A, the MPDCCH transmission (125) and the PUSCH transmission (130) may not be successful in the bad coverage of the eNB.

In this situation, the UE may have to retransmit Radio Link Control (RLC) Protocol Data Units (PDUs) . After the maximum RLC retransmission number is reached eventually, radio link failure will be declared. This may result in resource wastes, data interruptions, more power consumptions, and the like. Meanwhile, due to the insufficient CE mode-A configurations in the bad coverage, the transmission of the RRC reconfiguration message may also be failed even when the eNB is intended to reconfigure the CE mode B to the UE.

Embodiments of the present disclosure provide an improved RA procedure of a terminal device. The terminal device configured with a CE mode initiates a RA procedure in a further CE mode. During the RA procedure, the terminal device determines whether the dedicated backup configuration is enabled. If it is determined that the dedicated backup configuration is enabled, the terminal device detects a message from a network device by using the dedicated backup configuration.

In various embodiments of the present disclosure, the dedicated backup configuration can be used by the terminal device during the RA procedure if needed. In this way, the terminal device may switch to the configuration more adaptable to the radio conditions in time with no need of waiting for CE mode reconfiguration from the network side, so that the RA procedure is more effective and efficient. In addition, the network resources and the UE power are saved by disabling inappropriate CE mode configurations.

FIG. 2 illustrates an example communication network 200 in which embodiments of the present disclosure can be implemented. The network 200 comprises a terminal device 210 and a network device 220. It is to be understood that the numbers of network devices and terminal devices are shown only for the purpose of illustration without suggesting any limitation. The network 200 may include any suitable numbers of network devices and terminal devices.

The terminal device 210 may communicate with the network device 220 or with a further terminal device (not shown) via the network device 220. The communication may utilize any suitable technology that already exists or will be developed in the future. In some embodiments, the terminal device 210 may be implemented by an eMTC UE which communicates with or via the network device 220 using the MTC and/or eMTC technology.

In various embodiments of the present disclosure, the terminal device 120 is configured with a CE mode and a dedicated backup configuration. During a RA procedure initiated in a further CE mode, the dedicated backup configuration can be used by the terminal device 120 to improve this RA procedure.

FIG. 3 which shows a flowchart of an example method 300 in accordance with some embodiments of the present disclosure. The method 300 can be implemented at the terminal device 210 as shown in FIG. 2. For the purpose of discussion, the method 300 will be described with reference to FIG. 2.

At block 305, the terminal device 210 configured with a CE mode (referred to as a first CE mode) initiates a random access procedure in a different CE mode, referred to as a second CE mode. The first and second CE modes may implemented by any suitable CE mode. In some embodiments, the terminal device 210 is in a RRC connected state, and the first and second CE modes are the CE mode A and the CE mode B for the RRC connection state.

In some embodiments, before the initiation of the RA procedure at block 305, the terminal device 210 may initiate a RA procedure in the first mode. After the RA procedure in the first mode has failed, the terminal device 210 may initiate the RA procedure in the second CE mode. In some other embodiments, the terminal device 210 may directly use the second CE mode to initiate the RA procedure. For example, in the case that the terminal device 220 is configured with the CE mode A (as the first CE mode) , if the terminal device 220 moves to an area in the bad coverage of the network device 220, the terminal device 220 may choose to use the CE mode B (as the second CE mode) to initiate the RA procedure.

At block 310, the terminal device 210 determines whether a dedicated backup configuration is enabled. The dedicated backup configuration may be configured, for example, by the network device 220, before the RA procedure is initiated. For example, the dedicated backup configuration may be configured together with the configurations or parameters related to the first CE mode in RRC signaling or in a separate RRC reconfiguration message. Furthermore, the dedicated backup configuration may be reconfigured.

The dedicated backup configuration may include any suitable parameter that is different from the parameters related to the first CE mode. In some embodiments, the dedicated backup configuration may be associated with the second CE mode. Accordingly, the parameter (s) in the dedicated backup configuration may be related to the second CE mode. For example, in the embodiments where the first CE mode is the CE mode A, and the dedicated backup configuration may include one or more parameters related to the CE mode B, including, for example, the R-max, G factor which may be used together with the R-max to define the USS, a downlink control information (DCI) format indicating formats of the PDCCH, and the like.

In some embodiments, the dedicated backup configuration may be associated with one or more CE levels of the second CE mode. For example, the dedicated backup configuration may include a plurality of sets of parameters. Each set of parameters is associated with one of the CE levels. In the embodiments where the second CE mode is the CE mode B. The dedicated backup configuration may include two sets of parameters for the CE level 2 and the CE level 3, respectively. In some other embodiments, there may be no such a division of the parameters in the dedicated backup configuration. The dedicated backup configuration includes only one set of parameters for the second CE mode.

In some embodiments, in addition to the dedicated backup configuration, the terminal device 210 may be configured with one or more common backup configurations related to the second CE mode. Once the terminal device 210 initiates a RA attempt in the second CE mode, the common backup configurations may be used, which will be discussed in detail in the following paragraphs.

The terminal device 210 may determine whether to enable the dedicated backup configuration by considering any suitable factor. In some embodiments, if a few RA attempts (referred to as a first set of RA attempts) has failed in the first CE mode, the terminal device 210 may initiate further RA attempts (referred to as a second set of RA attempts) in the second CE mode. Upon the initiating of the second set of RA attempts, the terminal device 210 may determine that the dedicated backup configuration is enabled.

As another example, in the embodiments where the dedicated backup configuration includes a set of parameter for the CE level associated with the second CE mode, once the second set of RA attempts is initiated in the CE level, the terminal device 210 may determine that the set of parameters corresponding to the selected CE level are enabled.

Other events may also trigger the enabling of the dedicated backup configuration. For example, during handover of the terminal device 210 from the network device 220 to a further network device (not shown) , it may be determined that the dedicated backup configuration is enabled. As another example, if the measured or reported RSRP level is below a threshold, the terminal device 210 may determine the enabling of the dedicated backup configuration.

The enabling of the dedicated backup configuration may be also triggered based on UE mobility. For example, if the terminal device 210 moves to an area in the bad coverage of the network device 220, the terminal device 210 may determine that the dedicated backup configurations should be enabled. In addition or alternatively, the terminal device 210 may determine the enabling of the dedicated backup configuration based on cell deployment. For example, in the cell in the bad coverage, the terminal device 210 may determine the enabling of the dedicated backup configuration.

In some embodiments, an associated timer may be configured for the dedicated backup configuration. The terminal device 210 may obtain the dedicated backup configuration and the associated timer together from the network device 220. In this case, the terminal device 210 may determine whether to enable the dedicated backup configuration based on the timer. If the timer is expired, the terminal device 210 may determine that the dedicated backup configuration is disabled. In this way, the real-time of the configuration may be further ensured, and therefore the success probability of the RA procedure may be further improved.

At block 315, after it is determined that the dedicated backup configuration is enabled, the terminal device 210 detects a message from the network device 220 using the dedicated backup configuration. The message may include any suitable message during the RA procedure. In some embodiments, the message may include an uplink grant from the network device 220.

In some embodiments, the dedicated backup configuration may be used for detecting the message after Msg3 is successfully transmitted. For example, after the transmission or retransmission of Msg3 in the second CE mode is successful, the terminal device 210 may start to use/activate the dedicated backup configuration. The terminal device 210 may then use the dedicated backup configuration to detect the UL grant from the network device 220. During the Msg3 retransmission, the terminal device 210 may still monitor the CSS for the MPDCCH scrambled with temporary C-RNTI, which is specified by the second CE mode and broadcasted by the network device 220, for example. In these embodiments, the terminal device 210 may use the common configurations specified by the second CE mode before the Msg3 transmission or retransmission is successful.

In the embodiments where the dedicated backup configuration associated with the second CE mode and the terminal device 210 initiates the second set of RA attempts in the second CE mode, the dedicated backup configuration may be triggered upon the initiation of the second set of RA attempts. For example, the terminal device 210 may anonymously or implicitly switch to the second CE mode. In some embodiments, the terminal device 210 may use the common configurations for the second CE mode before the successful Msg3 transmission or retransmission and use the dedicated backup configuration for further communication. Alternatively, in the embodiments where the common backup configurations are also configured, the terminal device 210 may use the common backup configurations upon the initiating of the second RA attempt.

In some embodiments, the terminal device 210 may disable the dedicated backup configuration based on an indication of disabling the dedicated backup configuration. The indication may include an indication from the network device 220, such as an indication for CE mode configuration or reconfiguration. For example, in the case that the terminal device 210 is configured with the CE mode A, if the terminal device 210 receives an indication of reconfiguration to the CE mode B from the network device 220, the terminal device 210 may disable the dedicated backup configuration and starts to use the configured CE mode-B related parameters. As another example, if the network device 220 reconfigures some CE mode-A parameters to the terminal device 210, the terminal device 210 may also disable the dedicated backup configuration.

In the embodiments where the dedicated backup configuration is associated with the timer, the indication of disabling the dedicated backup configuration may be an indication that the associated timer is expired. The terminal device 210 may disable the dedicated backup configuration upon the expiration of the timer.

In some embodiments, the terminal device 210 may continue use of the dedicated backup configuration in response to an indication of the CE mode configuration or reconfiguration. For example, in the embodiments where the dedicated backup configuration is associated with the second CE mode, if the network device 220 indicates the terminal device 210 to switch to the second CE mode, the terminal device 210 may continue the use of the dedicated backup configuration while using the common configurations for the second CE mode.

In some embodiments, after RA procedure fails in the first CE mode, the terminal device 210 may automatically trigger radio link failure and re-establishment. In this case, the first CE mode configurations may be flushed before the terminal device 210 accesses to the re-established cell.

In some embodiments, an apparatus capable of performing the method 300 (for example, the terminal device 210) may comprise means for performing the respective steps of the method 300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the apparatus comprises: means for initiating a random access procedure in a second coverage enhancement (CE) mode different from a first CE mode that is configured; means for during the random access procedure, determining whether a dedicated backup configuration is enabled; and means for in response to determining that the dedicated backup configuration is enabled, detecting a message from a network device using the dedicated backup configuration.

In some embodiments, the means for initiating comprises: means for in response to a first set of random access attempts in the first CE mode having failed, initiating a second set of random access attempts in the second CE mode.

In some embodiments, the dedicated backup configuration is associated with the second CE mode. The means for determining comprises: means for in response to the initiating of the second set of random access attempts, determining that the dedicated backup configuration is enabled.

In some embodiments, the second CE mode is associated with a CE level, and the dedicated backup configuration comprises a set of parameters for the CE level. The means for initiating the second set of random access attempts comprises means for initiating the second set of random access attempts in the CE level. The means for determining comprises means for in response to the initiating of the second set of random access attempts in the CE level, determining that the set of parameters are enabled.

In some embodiments, the apparatus further comprises: means for in response to receiving an indication of switching the first CE mode to the second CE mode, continuing use of the dedicated backup configuration for further communication with the network device.

In some embodiments, the dedicated backup configuration is associated with a timer. The means for determining comprises: means for in response to expiration of the timer, determining that the dedicated backup configuration is disabled.

In some embodiments, the message comprises an uplink grant from the network device. The means for detecting comprises: means for in response to successful transmission of message 3, detecting the uplink grant from the network device by using the dedicated backup configuration.

In some embodiments, the apparatus further comprises: means for receiving the dedicated backup configuration from the network device in Radio Resource Control (RRC) signaling prior to the initiating of the random access procedure.

In some embodiments, the apparatus further comprises: means for disabling the dedicated backup configuration in response to an indication of disabling the dedicated backup configuration.

FIG. 4 is a simplified block diagram of a device 400 that is suitable for implementing embodiments of the present disclosure. The device 400 can be implemented at or as at least a part of the terminal device 210 as shown in FIG. 2.

As shown, the device 400 includes a processor 410, a memory 420 coupled to the processor 410, a communication module 440 coupled to the processor 410, and a communication interface (not shown) coupled to the communication module 440. The memory 410 stores at least a program 430. The communication module 440 is for bidirectional communications. The communication interface may represent any interface that is necessary for communication with a network element, such as Uu interface for communication between the eNB and the UE.

The program 430 is assumed to include program instructions that, when executed by the associated processor 410, enable the device 400 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to FIGS. 2-3. The embodiments herein may be implemented by computer software executable by the processor 410 of the device 400, or by hardware, or by a combination of software and hardware. The processor 410 may be configured to implement various embodiments of the present disclosure.

The memory 410 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 410 is shown in the device 400, there may be several physically distinct memory modules in the device 400. The processor 410 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 400 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 300 as described above with reference to FIGS. 2-3. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable media.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A method comprising:

at a terminal device configured with a first coverage enhancement (CE) mode,

initiating a random access procedure in a second CE mode different from the first CE mode; and

during the random access procedure,

determining whether a dedicated backup configuration is enabled, and

in response to determining that the dedicated backup configuration is enabled, detecting a message from a network device by using the dedicated backup configuration.
The method of claim 1, wherein initiating the random access procedure comprises:

in response to a first set of random access attempts in the first CE mode having failed, initiating a second set of random access attempts in the second CE mode.
The method of claim 2, wherein the dedicated backup configuration is associated with the second CE mode, and determining whether the dedicated backup configuration is enabled comprises:

in response to the initiating of the second set of random access attempts, determining that the dedicated backup configuration is enabled.
The method of claim 3, wherein the second CE mode is associated with a CE level, and the dedicated backup configuration comprises a set of parameters for the CE level,

wherein initiating the second set of random access attempts comprises initiating the second set of random access attempts in the CE level, and

wherein determining that the dedicated backup configuration is enabled comprises in response to the initiating of the second set of random access attempts in the CE level, determining that the set of parameters are enabled.
The method of any of claims 1-4, further comprising:

in response to receiving an indication of switching the first CE mode to the second CE mode, continuing use of the dedicated backup configuration for further communication with the network device.
The method of any of claims 1-5, wherein the dedicated backup configuration is associated with a timer, and determining whether the dedicated backup configuration is enabled comprises:

in response to expiration of the timer, determining that the dedicated backup configuration is disabled.
The method of any of claims 1-6, wherein the message comprises an uplink grant from the network device, and detecting the message from the network device comprises:

in response to successful transmission of message 3, detecting the uplink grant from the network device by using the dedicated backup configuration.
The method of any of claims 1-7, further comprising:

receiving the dedicated backup configuration from the network device in Radio Resource Control (RRC) signaling prior to the initiating of the random access procedure.
The method of any of claims 1-8, further comprising:

disabling the dedicated backup configuration in response to an indication of disabling the dedicated backup configuration.
A device, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the device to:

initiate a random access procedure in a second coverage enhancement (CE) mode different from a first CE mode that is configured; and

during the random access procedure,

determine whether a dedicated backup configuration is enabled, and

in response to determining that the dedicated backup configuration is enabled, detect a message from a network device by using the dedicated backup configuration.
The device of claim 10, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to:

in response to a first random access attempt in the first CE mode having failed, initiate a second random access attempt in the second CE mode.
The device of claim 11, wherein the dedicated backup configuration is associated with the second CE mode, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to:

in response to the initiating of the second random access attempt, determine that the dedicated backup configuration is enabled.
The device of claim 12, wherein the second CE mode is associated with a CE level, and the dedicated backup configuration comprises a set of parameters for the CE level; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to:

initiate the second random access attempt in the CE level, and

in response to the initiating of the second random access attempt in the CE level, determine that the set of parameters are enabled.
The device of any of claims 10-13, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:

in response to receiving an indication of switching the first CE mode to the second CE mode, continue use of the dedicated backup configuration for further communication with the network device.
The device of any of claims 10-14, wherein the dedicated backup configuration is associated with a timer, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to:

in response to expiration of the timer, determine that the dedicated backup configuration is disabled.
The device of any of claims 10-15, wherein the message comprises an uplink grant from the network device, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to:

in response to successful transmission of message 3, detect the uplink grant from the network device by using the dedicated backup configuration.
The device of any of claims 10-16, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:

receive the dedicated backup configuration from the network device in Radio Resource Control (RRC) signaling prior to the random access procedure.
The device of any of claims 10-17, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:

disable the dedicated backup configuration in response to an indication of disabling the dedicated backup configuration.
A computer readable storage medium storing a computer program thereon, the computer program, when executed by a processor, causing the processor to carry out the method according to any of claims 1 to 9.