WO2018227481A1

WO2018227481A1 - System and method for configuring system information in wireless network

Info

Publication number: WO2018227481A1
Application number: PCT/CN2017/088457
Authority: WO
Inventors: Yang Liu; Zhuang Liu; Yin Gao; He Huang
Original assignee: Zte Corporation
Priority date: 2017-06-15
Filing date: 2017-06-15
Publication date: 2018-12-20
Also published as: CN110603827B; CN110603827A

Abstract

The present disclosure relates to a method and system for configuring system information in a wireless network. In one embodiment, a method implemented on a first node is disclosed. The method comprises: generating a message related to system information that is associated with at least one cell in a wireless network; and transmitting the message to a second node associated with the at least one cell, wherein the first node and the second node cooperate to serve the at least one cell as a base station.

Description

SYSTEM AND METHOD FOR CONFIGURING SYSTEM INFORMATION IN A WIRELESS NETWORK

TECHNICAL FIELD

The disclosure relates generally to wireless communications and, more particularly, to systems and methods for configuring system information in a wireless network.

BACKGROUND

Future wireless communication systems, such as the 5G New Radio (NR) system, will have a novel network architecture and more flexibility in networking. In the 5G NR network, the base station (BS) at the wireless access network side can be divided into two functional entities: a centralized processing network element CU (Centralized Unit) and a distributed processing network element DU (Distributed Unit) . There is an ideal and/or non-ideal front-haul transmission and connections between the DU and the CU. In addition, this CU-DU separation architecture can also be suitable for future 4G evolution.

After a terminal completes the cell search and determines to be a resident of the cell, the terminal needs to acquire the system information of the cell so as to know how the cell is configured and to access the cell to work. The cell will keep sending the system information associated with the cell, and the terminal user equipment (UE) will acquire the information when it is needed. Some basic characteristics of system information transmission comprise: each cell transmits the system information associated with the cell by means of broadcasting； all system information is continuously broadcasted by either pre-configuration or pre-scheduling； and the system information is divided into multiple transport blocks according to features and functions. For example, important ones among the transport blocks, such as Master Information Block (MIB) and System Information Block (referred to as SIB1) , are transmitted by fixed pre-configuration (including transmission timing and/or transmission resources) . Other transport blocks are transmitted in form of pre-scheduling (including transmission timing and/or transmission resources) , and the scheduling information is usually in SIB1.

Under the above system information transmission mechanism, with the introduction of new technologies, transmission blocks become more； content size of the system information content becomes larger； and corresponding resource consumption keeps increasing. Moreover, many of the transport blocks designed specifically for new technologies are actually less likely to be demanded. As such, a continuous broadcast of these transport blocks will waste resources and increase the power consumption of network-side devices.

In response to this problem, the industry has begun to study methods for classifying system information according to the importance of information. One class includes the essential system information, which still uses the broadcast mechanism； and another class includes other system information, called non-essential system information, which uses the on-demand broadcast mechanism only. The essential system information typically includes very critical system information related to the initial access and/or cell residence, such that the information that the cell needs to broadcast is greatly compressed, and the essential system information is periodically broadcasted. The remaining system information belongs the second class, and can use the broadcast transmission mechanism； but they are only transmitted on-demand, rather than periodically, in order to improve resource utilization efficiency.

In a situation of an integrated base station, the system information of the cell is configured by its associated base station and circulated in a certain period, where the UE will acquire the system information when needed. But after the base stations are separated into centralized network elements CUs and distributed network elements DUs, there is no existing solution about how the system information is broadcasted, via the CU and DU, to the UE, or about how the CU and DU cooperate when the system information configuation is updated. So there is an urgent need to propose a new solution for configurating the system information in a network environment of separated CU-DU network elements.

SUMMARY

The exemplary embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, exemplary systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the present disclosure.

In one embodiment, a method implemented on a first node is disclosed. The method comprises: generating a message related to system information that is associated with at least one cell in a wireless network； and transmitting the message to a second node associated with the at least one cell, wherein the first node and the second node cooperate to serve the at least one cell as a base station.

In a further embodiment, a method implemented on a first node is disclosed. The method comprises: receiving, from a second node, a message related to system information that is associated with at least one cell in a wireless network, wherein the first node and the second node cooperate to serve the at least one cell as a base station； and transmitting a response to the second node, wherein the response indicates whether content of the message is successfully obtained by the first node or not.

In another embodiment, a first node is disclosed. The first node comprises: a system information generator configured to generate a message related to system information that is associated with at least one cell in a wireless network； and a transmitter configured to transmit the message to a second node associated with the at least one cell, wherein the first node and the second node cooperate to serve the at least one cell as a base station.

In yet another embodiment, a first node is disclosed. The first node comprises: a receiver configured to receive, from a second node, a message related to system information that is associated with at least one cell in a wireless network, wherein the first node and the second node cooperate to serve the at least one cell as a base station； and a transmitter configured to transmit a response to the second node, wherein the response indicates whether content of the message is successfully obtained by the first node or not.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of the present disclosure are described in detail below with reference to the following Figures. The drawings are provided for purposes of illustration only and merely depict exemplary embodiments of the present disclosure to facilitate the reader's understanding of the present disclosure. Therefore, the drawings should not be considered limiting of the breadth, scope, or applicability of the present disclosure. It should be noted that for clarity and ease of illustration these drawings are not necessarily drawn to scale.

FIG. 1 illustrates a CU-DU separation structure of a base station, in accordance with some embodiments of the present disclosure.

FIG. 2 illustrates an exemplary block diagram of a centralized unit (CU) , in accordance with some embodiments of the present disclosure.

FIG. 3 illustrates exemplary system information (SI) to be configured or reconfigured in a wireless network, in accordance with some embodiments of the present disclosure.

FIG. 4 illustrates an exemplary block diagram of a distributed unit (DU) , in accordance with some embodiments of the present disclosure.

FIG. 5 illustrates an exemplary method of system information configuration between CU and DU, in accordance with some embodiments of the present disclosure.

FIG. 6 illustrates an exemplary method of system information reconfiguration between CU and DU, in accordance with some embodiments of the present disclosure.

FIG. 7 illustrates an exemplary method for UE to obtain system information configuration on-demand, in accordance with some embodiments of the present disclosure.

FIG. 8 illustrates an exemplary method for UE to obtain system information reconfiguration on-demand, in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Various exemplary embodiments of the present disclosure are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the present disclosure. As would be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein can be made without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein are merely exemplary approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be re-arranged while remaining within the scope of the present disclosure. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the present disclosure is not limited to the specific order or hierarchy presented unless expressly stated otherwise.

In a 5G NR network, the BS is separated into a centralized network element CU and a distributed network element DU. FIG. 1 illustrates a CU-DU separation structure of a base station 100, in accordance with some embodiments of the present disclosure. As shown in FIG. 1, the BS 100 is divided into a CU 110 and a DU 120. As such, the CU 110 and the DU 120 can cooperate to serve a cell as a base station, where there is an ideal or non-ideal front-haul interface 130 between the CU 110 and the DU 120.

In one embodiment, a CU may control a plurality of DUs at the same time, while a DU can be associated with one cell or a cell list that includes one or more cells. By controlling a number of DUs with a CU, the system can have a baseband centralized processing and provide distributed remote services to users in a cloud architecture. In a CU-DU separation network architecture, delay-insensitive network functions may be placed in the CU； and delay-sensitive network functions may be placed in the DU. Accordingly, a CU and a DU may have different hardware and structure for implementing the different network functions.

In the current situation of CU-DU network element separation, the issue of system information configuration between CU and DU has not been effectively solved. For example, how the system information is broadcasted, via the CU and DU, to the UE； and how the CU and DU cooperate and work together when the system information configuration is updated. In order to solve these problems, the present teaching discloses methods and systems for configuring and/or reconfiguring system information in a CU-DU separation network architecture.

The present disclosure is applicable to all system information configuration problems in a 5G NR newtork involving a CU-DU separation scenario.

FIG. 2 illustrates an exemplary block diagram of a CU 110, in accordance with some embodiments of the present disclosure. The CU 110 is an example of a device that can be configured to implement the various methods described herein. As shown in FIG. 2, the CU 110 includes a housing 240 containing: a system clock 202, a processor 204, a memory 206, a transceiver 210 comprising a transmitter 212 and receiver 214, a power module 208, a paging generator 220, and a system information generator 222.

In this embodiment, the system clock 202 provides the timing signals to the processor 204 for controlling the timing of all operations of the CU 110. The processor 204 controls the general operation of the CU 110 and can include one or more processing circuits or modules such as a central processing unit (CPU) and/or any combination of general-purpose microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate array (FPGAs) , programmable logic devices (PLDs) , controllers, state machines, gated logic, discrete hardware components, dedicated hardware finite state machines, or any other suitable circuits, devices and/or structures that can perform calculations or other manipulations of data. As described in further detail below, the processor 204 may calculate a modification period indicating an effective time when the SI associated with a cell will be modified, in accordance with various embodiments of the present disclosure.

The memory 206, which can include both read-only memory (ROM) and random access memory (RAM) , can provide instructions and data to the processor 204. A portion of the memory 206 can also include non-volatile random access memory (NVRAM) . The processor 204 typically performs logical and arithmetic operations based on program instructions stored within the memory 206. The instructions (a. k. a., software) stored in the memory 206 can be executed by the processor 204 to perform the methods described herein. The processor 204 and memory 206 together form a processing system that stores and executes software. As used herein, “software” means any type of instructions, whether referred to as software, firmware, middleware, microcode, etc. which can configure a machine or device to perform one or more desired functions or processes. Instructions can include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code) . The instructions, when executed by the one or more processors, cause the processing system to perform the various functions described herein.

The transceiver 210, which includes the transmitter 212 and receiver 214, allows the CU 110 to transmit and receive data to and from a remote device (e.g., a DU) . In one embodiment, an antenna 250 may be attached to the housing 240 and electrically coupled to the transceiver 210. In various embodiments, the CU 110 includes (not shown) multiple transmitters, multiple receivers, multiple transceivers, and/or multiple antennas. The transmitter 212 can be configured to wirelessly transmit packets having different packet types or functions, such packets being generated by the processor 204. Similarly, the receiver 214 is configured to receive packets having different packet types or functions, and the processor 204 is configured to process packets of a plurality of different packet types. For example, the processor 204 can be configured to determine the type of packet and to process the packet and/or fields of the packet accordingly. In another embodiment, the CU 110 may communicate with one or more DUs via fiber-optic communication, such that the transmitter 212 and the receiver 214 can be configured to transmit and receive signals respectively through an optical fiber.

The system information generator 222 may generate a message related to SI that is associated with one cell or a cell list including one or more cells in a wireless network. After determining a DU that is associated with the one or more cells, the system information generator 222 may send the message to the transmitter 212, and instruct the transmitter 212 to transmit the message to the DU. In one embodiment, when multiple DUs are associated with the cell list, the system information generator 222 may instruct the transmitter 212 to transmit the SI configuration message to each of the multiple DUs. The SI may be generated at a Radio Resource Control (RRC) layer, whose functions are covered by a CU.

In one embodiment, the SI may include both minimum SI that is required for each UE in the one or more cells, and other SI. For example, the minimum SI may include MIB, SIB1, etc. In another embodiment, the minimum SI, e.g. the MIB, is pre-set based on the communication protocol, and does not need to be included in the SI to be configured.

In one embodiment, the message (referred as SI configuration message) includes configured SI for the one or more cells. The receiver 214 may receive a response from the DU. The response indicates whether DU has successfully obtained content of the SI configuration message. If the response indicates that DU has not successfully obtained content of the SI configuration message, the transmitter 212 may re-send the SI configuration message after a certain period of time. Alternatively, if the response indicates that DU has not successfully obtained content of the SI configuration message, the system information generator 222 may generate a new SI configuration message including latest SI of the one or more cells, and instruct the transmitter 212 to transmit the new SI configuration message to the DU.

In another embodiment, the message (referred as SI reconfiguration message) includes reconfigured SI for the one or more cells. The reconfigured SI may include only a modified portion of the originally configured SI. In this case, the receiver 214 may receive a response from the DU. The response indicates whether DU has successfully obtained content of the SI reconfiguration message. If the response indicates that DU has not successfully obtained content of the SI reconfiguration message, the transmitter 212 may re-send the SI reconfiguration message after a certain period of time. Alternatively, if the response indicates that DU has not successfully obtained content of the SI reconfiguration message, the system information generator 222 may generate a new SI reconfiguration message including latest modified SI of the one or more cells, and instruct the transmitter 212 to transmit the new SI reconfiguration message to the DU. If the response indicates that DU has successfully obtained content of the SI reconfiguration message, the receiver 214 may inform the paging generator 220 to generate a paging message.

The paging generator 220 in this example can generate a paging message when a response received at the receiver 214 indicates that the content of the SI reconfiguration message is successfully obtained by a DU. The paging message indicates a modification of the SI in the one or more cells associated with that DU. The paging generator 220 may then instruct the transmitter 212 to send the paging message in the one or more cells, via the DU. For example, the transmitter 212 may transmit the paging message to the DU； and the DU will forward the paging message in the one or more cells without decoding the paging message. A UE in the one or more cells, after receiving the paging message, can know that there is a change or modification of the SI, but does not know the modified content of the SI. Then, the DU may send the modified content of the SI to the UE, either by broadcasting or by on-demand.

In one embodiment, the SI of a cell is kept to be the same across an entire modification period, and can only be changed or modified at the beginning of a next modification period after a notification of the change one period before. For example, when a modification period is ten minutes, if the system information generator 222 generates some reconfigured SI that is a modification of some portion of the SI of the cell, the CU 110 may notify the DU associated with the cell at the beginning of a first modification period. After the DU successfully obtained the reconfigured SI, the cell may start to use the reconfigured SI ten minutes afterwards, i.e. from the beginning of the next modification period after the first period (second modification period) . Otherwise, if the DU failed to obtain the reconfigured SI, the cell will use the old SI through the second modification period； and the reconfigured SI can only be used after the second modification period, assuming it can be successfully notified to the DU at the beginning of the second modification period.

As such, it is important for the CU and DU to agree on the modification period about the SI reconfiguration. In one embodiment, the processor 204 may calculate a modification period that indicates an effective time when the SI will be modified next, and instruct the transmitter 212 to transmit the modification period to the DU. In another embodiment, the transmitter 212 may send one or more parameters to the DU, such that the DU can calculate the modification period based on the one or more parameters. The one or more parameters may be carried in the SI configuration message, the SI reconfiguration message, or other messages, e.g. a physical layer indication message like downlink control information (DCI) related to cell setup.

In one embodiment, the transmitter 212 may send at least one of the parameters modificationPeriodCoeff and defaultPagingCycle to the DU for the DU to calculate the modification period based on these parameters. The CU may also notify the DU about any changes of the parameters modificationPeriodCoeff and/or defaultPagingCycle themselves.

The power module 208 can include a power source such as one or more batteries, and a power regulator, to provide regulated power to each of the above-described modules in FIG. 2. In some embodiments, if the CU 110 is coupled to a dedicated external power source (e.g., a wall electrical outlet) , the power module 208 can include a transformer and a power regulator.

The various modules discussed above are coupled together by a bus system 230. The bus system 230 can include a data bus and, for example, a power bus, a control signal bus, and/or a status signal bus in addition to the data bus. It is understood that the modules of the CU 110 can be operatively coupled to one another using any suitable techniques and mediums.

Although a number of separate modules or components are illustrated in FIG. 2, persons of ordinary skill in the art will understand that one or more of the modules can be combined or commonly implemented. For example, the processor 204 can implement not only the functionality described above with respect to the processor 204, but also implement the functionality described above with respect to the paging generator 220. Conversely, each of the modules illustrated in FIG. 2 can be implemented using a plurality of separate components or elements.

FIG. 3 illustrates exemplary system information (SI) to be configured or reconfigured in a wireless network, in accordance with some embodiments of the present disclosure. As shown in FIG. 3, the exemplary SI 300 comprise: a cell ID list 310 including cell IDs of the cells in the cell list associated with the SI (or a cell ID of the cell associated with the SI) ； a separately encoded container 320 for each SI element in the SI； scheduling information 330； indication 340 of broadcast SI or on-demand SI, indicating whether each SI element is to be sent to UEs by broadcasting or on-demand； indication 350 of SI acquiring scheme, indicating e.g. whether each SI element or each SI element combination is to be acquired by UE via Msg1, Msg3, or a combination of Msg1 and Msg3； a mapping relationship 360 between random access channel (RACH) resources and system information blocks (SIBs) , wherein the RACH resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and configuration parameter information 370 related to SI reconfiguration.

It can be understood that, an SI reconfiguration message may include only the modified SI elements, but not include the unmodified SI. For example, when the CU modifies the scheduling information 330, the CU may send the modified scheduling information in the SI reconfiguration message to the DU, without sending other unmodified SI listed in FIG. 3.

It can also be understood that, as the CU sends configured or reconfigured SI elements that are encoded in containers at RRC layer, the DU does not need to decode the containers； but the UEs which also include a corresponding RRC layer, can decode the containers to obtain the decoded SI.

FIG. 4 illustrates an exemplary block diagram of a DU 120, in accordance with some embodiments of the present disclosure. The DU 120 is an example of a device that can be configured to implement the various methods described herein. As shown in FIG. 4, the DU 120 includes a housing 440 containing: a system clock 402, a processor 404, a memory 406, a transceiver 410 comprising a transmitter 412 and receiver 414, a power module 408, a paging forwarding unit 420, and a system information broadcaster 422.

In this embodiment, the system clock 402, the processor 404, the memory 406, the transceiver 410 and the power module 408 work similarly to the system clock 202, the processor 204, the memory 206, the transceiver 210 and the power module 208 in the CU 110.

In one embodiment, an antenna 450 may be attached to the housing 440 and electrically coupled to the transceiver 410. In various embodiments, the DU 120 includes (not shown) multiple transmitters, multiple receivers, multiple transceivers, and/or multiple antennas. In another embodiment, the DU 120 may communicate with a CU controlling the DU 120 via fiber-optic communication, such that the transmitter 412 and the receiver 414 can be configured to transmit and receive signals respectively through an optical fiber.

In one embodiment, the receiver 414 may receive a message related to SI that is associated with one cell or a cell list including one or more cells served by a combination of the CU and the DU as a base station in a wireless network.

In one embodiment, the SI may include both minimum SI that is required for each UE in the one or more cells, and other SI. For example, the minimum SI may include MIB, SIB1, etc. In another embodiment, the minimum SI, e.g. the MIB, is pre-set based on the communication protocol, and does not need to be included in the SI to be configured or reconfigured.

In one embodiment, the message (referred as SI configuration message) includes configured SI for the one or more cells. The transmitter 412 may transmit a response to the CU. The response indicates whether the DU 120 has successfully obtained content of the SI configuration message. If the DU has successfully obtained content of the SI configuration message, the system information broadcaster 422 in this example broadcasts via the transmitter 412, in the one or more cells, either all of the configured SI or a portion of the configured SI based on an on-demand request from a UE. In one embodiment, the system information broadcaster 422 broadcasts all of the configured SI in the one or more cells according to scheduling information in the configured SI, after successfully obtaining the content of the message. In another embodiment, after successfully obtaining the content of the message, the system information broadcaster 422 waits for the receiver 414 to receive, from a UE in the one or more cells, an on-demand request for a portion of the configured SI needed by the UE. Then, in response to the on-demand request, the system information broadcaster 422 broadcast, via the transmitter 412, the requested portion of the configured SI to the UE according to the scheduling information in the configured SI.

In another embodiment, the message (referred as SI reconfiguration message) includes reconfigured SI for the one or more cells. The reconfigured SI may include only a modified portion of the originally configured SI. In this embodiment, the transmitter 412 may transmit a response to the CU to indicate whether the DU 120 has successfully obtained content of the SI reconfiguration message. If the response indicates that DU has successfully obtained content of the SI reconfiguration message, the receiver 414 may receive a paging message from the CU. The paging message indicates a modification of the SI in the one or more cells associated with that DU.

The paging forwarding unit 420 in this example can forward the paging message in the one or more cells without decoding the paging message. A UE in the one or more cells, after receiving the paging message, can know that there is a change or modification of the SI, but does not know the modified content of the SI. Then, the system information broadcaster 422 may broadcast the modified content of the SI to the UE, either by broadcasting or by on-demand, similar to the broadcasting of configured SI by the system information broadcaster 422 as discussed before.

It is important for the CU and DU to agree on the modification period about the SI reconfiguration. In one embodiment, the CU may calculate a modification period that indicates an effective time when the SI will be modified next, and transmit the modification period to the DU 120. In another embodiment, the receiver 414 may receive one or more parameters from the CU, such that the processor 404 can calculate the modification period based on the one or more parameters. The one or more parameters may be carried in the SI configuration message, the SI reconfiguration message, or other messages, e.g. a physical layer indication message like DCI related to cell setup.

The various modules discussed above are coupled together by a bus system 430. The bus system 430 can include a data bus and, for example, a power bus, a control signal bus, and/or a status signal bus in addition to the data bus. It is understood that the modules of the DU 120 can be operatively coupled to one another using any suitable techniques and mediums.

Although a number of separate modules or components are illustrated in FIG. 4, persons of ordinary skill in the art will understand that one or more of the modules can be combined or commonly implemented. For example, the processor 404 can implement not only the functionality described above with respect to the processor 404, but also implement the functionality described above with respect to the paging forwarding unit 420. Conversely, each of the modules illustrated in FIG. 4 can be implemented using a plurality of separate components or elements.

FIG. 5 illustrates an exemplary method of system information configuration between a CU 510 and a DU 520, in accordance with some embodiments of the present disclosure. In one embodiment, the CU 510 may have a structure as shown in FIG. 2； and the DU 520 may have a structure as shown in FIG. 4. As shown in FIG. 5, when a system information configuration is needed, the CU 510 sends, at step 542, a system information configuration message to the DU 520, where the message includes but is not limited to the following information: cell IDs of the cells in the cell list associated with the SI (or a cell ID of the cell associated with the SI) ； a separately encoded container for each SI element in the SI； scheduling information； indication of broadcast SI or on-demand SI, indicating whether each SI element is to be sent to UEs by broadcasting or on-demand； indication of SI acquiring scheme, indicating e.g. whether each SI element or each SI element combination is to be acquired by UE via Msg1, Msg3, or a combination of Msg1 and Msg3； a mapping relationship between random access channel (RACH) resources and system information blocks (SIBs) , wherein the RACH resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and parameter information related to reconfiguration of the SI.

Optionally, after the DU 520 receives the system information configuration message sent by the CU 510, the DU 520 sends, at step 544, an SI configuration response message to the CU 510 to indicate that the reception of system information configuration succeeded or failed.

After the DU 520 has successfully obtained content of the above-mentioned system information configuration message, the DU 520 transmits, at step 552, the system information to UEs, e.g. the UE 530, in the one or more cells associated with the DU 520, by means of broadcasting according to the scheduling information in the system information.

FIG. 6 illustrates an exemplary method of system information reconfiguration between a CU 610 and a DU 620, in accordance with some embodiments of the present disclosure. In one embodiment, the CU 610 may have a structure as shown in FIG. 2； and the DU 620 may have a structure as shown in FIG. 4. As shown in FIG. 6, the CU 610 sends, at step 642, a system information reconfiguration message to the DU 620, where the message includes information related to the modified/updated part of the system information, including: cell IDs of the cells in the cell list associated with the reconfigured SI (or a cell ID of the cell associated with the reconfigured SI) ； a separately encoded container for each reconfigured SI element； modified scheduling information； indication of modified broadcast SI or modified on-demand SI, indicating whether each modified SI element is to be sent to UEs by broadcasting or on-demand； indication of modified SI acquiring scheme, indicating e.g. whether each modified SI element or each modified SI element combination is to be acquired by UE via Msg1, Msg3, or a combination of Msg1 and Msg3； a modified mapping relationship between random access channel (RACH) resources and system information blocks (SIBs) , wherein the RACH resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and parameter information related to reconfiguration of the SI, etc. The system information that is not modified does not need to be sent. Optionally, for the calculation of a modification period for modifying the system information, one method is for the CU 610 to calculate the period and send it to the DU 620； another method is for the CU 610 to send all parameters related to the modification period calculation to the DU 620, and the DU 620 will calculate the modification period.

Optionally, after the DU 620 receives the system information reconfiguration message sent by the CU 610, the DU 620 sends, at step 644, an SI configuration response message to the CU 610 to indicate whether the reception of the modified system information configuration succeeded or failed.

After the DU 620 has successfully obtained the system information reconfiguration message, the CU 610 sends a paging message to UEs, e.g. the UE 630, in the one or more cells, through the DU 620. The paging message comprises an indication indicating a modification/update of the system information in the one or more cells. Then the DU 620 transmits, at step 652, the system information to UEs, e.g. the UE 630, in the one or more cells associated with the DU 620, by means of broadcasting according to the scheduling information in the system information.

FIG. 7 illustrates an exemplary method for UE to obtain system information configuration on-demand, in accordance with some embodiments of the present disclosure. In one embodiment, the CU 710 may have a structure as shown in FIG. 2； and the DU 720 may have a structure as shown in FIG. 4. As shown in FIG. 7, at step 742, the CU 710 sends a system information configuration message including all system information configuration to the DU 720, where the message includes but is not limited to the following information: cell IDs of the cells in the cell list associated with the SI (or a cell ID of the cell associated with the SI) ； a separately encoded container for each SI element in the SI； scheduling information； indication of broadcast SI or on-demand SI, indicating whether each SI element is to be sent to UEs by broadcasting or on-demand； indication of SI acquiring scheme, indicating e.g. whether each SI element or each SI element combination is to be acquired by UE via Msg1, Msg3, or a combination of Msg1 and Msg3； a mapping relationship between random access channel (RACH) resources and system information blocks (SIBs) , wherein the RACH resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and parameter information related to reconfiguration of the SI.

Optionally, after the DU 720 receives the system information configuration message sent by the CU 710, the DU 720 sends, at step 744, an SI configuration response message to the CU 710 to indicate that the reception of system information configuration succeeded or failed.

After the DU 720 has successfully obtained content of the above-mentioned system information configuration message, the DU 720 stores the system information, and wait to receive, at step 752, an on-demand system information request from a UE, e.g. the UE 730. The UE 730 sends the on-demand SI request based on the UE’s own situation. Optionally, the on-demand SI request may be in the form of Msg1 (i.e. Preamble) or Msg3.

After the DU 720 receives the on-demand system information request from the UE 730, the DU 720 sends, at step 754, the partial system information requested by the UE 730, to the UE 730 by means of broadcasting, according to the scheduling information in the configured SI. The partial system information includes but is not limited to the on-demand SI.

FIG. 8 illustrates an exemplary method for UE to obtain system information reconfiguration on-demand, in accordance with some embodiments of the present disclosure. In one embodiment, the CU 810 may have a structure as shown in FIG. 2； and the DU 820 may have a structure as shown in FIG. 4. As shown in FIG. 8, the CU 810 sends, at step 842, a system information reconfiguration message to the DU 820, where the message includes information related to the modified/updated part of the system information, including: cell IDs of the cells in the cell list associated with the reconfigured SI (or a cell ID of the cell associated with the reconfigured SI) ； a separately encoded container for each reconfigured SI element； modified scheduling information； indication of modified broadcast SI or modified on-demand SI, indicating whether each modified SI element is to be sent to UEs by broadcasting or on-demand； indication of modified SI acquiring scheme, indicating e.g. whether each modified SI element or each modified SI element combination is to be acquired by UE via Msg1, Msg3, or a combination of Msg1 and Msg3； a modified mapping relationship between random access channel (RACH) resources and system information blocks (SIBs) , wherein the RACH resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and parameter information related to reconfiguration of the SI, etc. The system information that is not modified does not need to be sent. Optionally, for the calculation of a modification period for modifying the system information, one method is for the CU 810 to calculate the period and send it to the DU 820； another method is for the CU 810 to send all parameters related to the modification period calculation to the DU 820, and the DU 820 will calculate the modification period.

Optionally, after the DU 820 receives the system information reconfiguration message sent by the CU 810, the DU 820 sends, at step 844, an SI configuration response message to the CU 810 to indicate whether the reception of the modified system information configuration succeeded or failed.

After the DU 820 has successfully obtained the system information reconfiguration message, the CU 810 sends a paging message to UEs, e.g. the UE 830, in the one or more cells, through the DU 820. The paging message comprises an indication indicating a modification/update of the system information in the one or more cells. Then the DU 820 stores the reconfigured SI, and wait to receive, at step 852, an on-demand updated system information request from a UE, e.g. the UE 830. The UE 830 sends the on-demand updated SI request based on the UE’s own situation. Optionally, the on-demand updated SI request may be in the form of Msg1 (i.e. Preamble) or Msg3.

After the DU 820 receives the on-demand updated system information request from the UE 830, the DU 820 sends, at step 854, the partial system information requested by the UE 830, to the UE 830 by means of broadcasting, according to the scheduling information in the reconfigured SI. The partial system information includes but is not limited to the on-demand updated SI.

When the DU sends configured or reconfigured SI to a UE, the DU can modify part of the stream field of the SI, e.g. system frame number (SFN) , indication of whether on-demand SI is being broadcasted, etc.

In one embodiment, if there is a modification of the indication information that indicates whether the on-demand SI is being broadcasted, the indication information can be maintained on the DU side, where the DU can modify the stream field, corresponding to the indication information, in the SI container.

In one embodiment, a value tag systemInfoValueTag in SIB1 indicates if a change has occurred in the SI messages. As such, a UE can also check this value tag to verify whether the previous SI is still valid, without receiving the paging message. In addition, another method to indicate the SI changes is by using downlink control information (DCI) .

While various embodiments of the present disclosure have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand exemplary features and functions of the present disclosure. Such persons would understand, however, that the present disclosure is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

It is also understood that any reference to an element herein using a designation such as "first, " "second, " and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner.

Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits and symbols, for example, which may be referenced in the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

A person of ordinary skill in the art would further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two) , firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software module) , or any combination of these techniques.

To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure. In accordance with various embodiments, a processor, device, component, circuit, structure, machine, module, etc. can be configured to perform one or more of the functions described herein. The term “configured to” or “configured for” as used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, module, etc. that is physically constructed, programmed and/or arranged to perform the specified operation or function.

Furthermore, a person of ordinary skill in the art would understand that various illustrative logical blocks, modules, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include 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, or any combination thereof. The logical blocks, modules, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.

If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

In this document, the term "module" as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules； however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the present disclosure.

Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present disclosure. It will be appreciated that, for clarity purposes, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present disclosure. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other implementations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.

Claims

A method implemented on a first node, the method comprising:

generating a message related to system information that is associated with at least one cell in a wireless network； and

transmitting the message to a second node associated with the at least one cell, wherein the first node and the second node cooperate to serve the at least one cell as a base station.
The method of claim 1, wherein:

the first node is a centralized unit of the base station； and

the second node is a distributed unit of the base station, wherein the system information comprises at least one of: minimum system information that is required for each user equipment in the at least one cell, and other system information.
The method of claim 1, further comprising:

receiving a response from the second node, wherein the response indicates whether content of the message is successfully obtained by the second node or not.
The method of claim 3, wherein:

the content of the message includes configured system information for the at least one cell；

the second node broadcasts the configured system information in the at least one cell according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The method of claim 3, wherein:

the content of the message includes configured system information for the at least one cell；

the second node receives, from a user equipment in the at least one cell, an on-demand request for a portion of the configured system information； and

the second node broadcasts the portion of the configured system information to the user equipment according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The method of claim 3, wherein:

the content of the message includes reconfigured system information for the at least one cell；

the method further comprises

generating a paging message when the response indicates the content of the message is successfully obtained by the second node, the paging message indicating a modification of the system information, and

sending, via the second node, the paging message in the at least one cell.
The method of claim 6, wherein:

the second node broadcasts the reconfigured system information in the at least one cell according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The method of claim 6, wherein:

the second node receives, from a user equipment in the at least one cell, an on-demand request for a portion of the reconfigured system information； and

the second node broadcasts the portion of the reconfigured system information to the user equipment according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The method of claim 1, wherein the system information comprises at least one of:

an identification of the at least one cell；

a separately encoded container for each system information element of the system information；

scheduling information；

indication information indicating whether each system information element is to be sent to user equipments in the at least one cell by broadcasting or on-demand；

an indication of system information acquiring scheme, indicating whether each system information element or each system information element combination is to be acquired by user equipment via Msg1, Msg3, or a combination of Msg1 and Msg3；

a mapping relationship between random access channel resources and system information blocks, wherein the random access channel resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and

configuration parameter information related to system information reconfiguration.
The method of claim 1, wherein the system information comprises at least one of:

a modification period indicating an effective time when the system information will be modified, wherein the modification period is calculated and indicated by the first node； and

one or more parameters to be utilized for calculating the modification period by the second node.
The method of claim 10, wherein the one or more parameters are carried in the message.
The method of claim 10, wherein the one or more parameters are indicated by a physical layer indication message related to cell setup.
A method implemented on a first node, the method comprising:

receiving, from a second node, a message related to system information that is associated with at least one cell in a wireless network, wherein the first node and the second node cooperate to serve the at least one cell as a base station； and

transmitting a response to the second node, wherein the response indicates whether content of the message is successfully obtained by the first node or not.
The method of claim 13, wherein:

the first node is a distributed unit of the base station； and

the second node is a centralized unit of the base station.
The method of claim 13, wherein the system information comprises at least one of: minimum system information that is required for each user equipment in the at least one cell, and other system information.
The method of claim 13, wherein:

the content of the message includes configured system information for the at least one cell； and

the method further comprises broadcasting the configured system information in the at least one cell according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The method of claim 13, wherein:

the content of the message includes configured system information for the at least one cell； and

the method further comprises

receiving, from a user equipment in the at least one cell, an on-demand request for a portion of the configured system information, and

broadcasting the portion of the configured system information to the user equipment according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The method of claim 13, wherein:

the content of the message includes reconfigured system information for the at least one cell；

the method further comprises

receiving a paging message from the second node when the response indicates the content of the message is successfully obtained by the first node, the paging message indicating a modification of the system information, and

sending the paging message in the at least one cell.
The method of claim 18, further comprising:

broadcasting the reconfigured system information in the at least one cell according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The method of claim 18, further comprising:

receiving, from a user equipment in the at least one cell, an on-demand request for a portion of the reconfigured system information； and

broadcasting the portion of the reconfigured system information to the user equipment according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The method of claim 13, wherein the system information comprises at least one of:

an identification of the at least one cell；

a separately encoded container for each system information element of the system information；

scheduling information；

indication information indicating whether each system information element is to be sent to user equipments in the at least one cell by broadcasting or on-demand；

an indication of system information acquiring scheme, indicating whether each system information element or each system information element combination is to be acquired by user equipment via Msg1, Msg3, or a combination of Msg1 and Msg3；

a mapping relationship between random access channel resources and system information blocks, wherein the random access channel resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and

configuration parameter information related to system information reconfiguration.
The method of claim 13, wherein the system information comprises at least one of:

a modification period indicating an effective time when the system information will be modified, wherein the modification period is calculated and indicated by the second node； and

one or more parameters to be utilized for calculating the modification period by the first node.
The method of claim 22, wherein the one or more parameters are carried in the message.
The method of claim 22, wherein the one or more parameters are indicated by a physical layer indication message related to cell setup.
A first node, comprising:

a system information generator configured to generate a message related to system information that is associated with at least one cell in a wireless network； and

a transmitter configured to transmit the message to a second node associated with the at least one cell, wherein the first node and the second node cooperate to serve the at least one cell as a base station.
The first node of claim 25, wherein:

the first node is a centralized unit of the base station； and

the second node is a distributed unit of the base station, wherein the system information comprises at least one of: minimum system information that is required for each user equipment in the at least one cell, and other system information.
The first node of claim 25, further comprising:

a receiver configured to receive a response from the second node, wherein the response indicates whether content of the message is successfully obtained by the second node or not.
The first node of claim 27, wherein:

the content of the message includes configured system information for the at least one cell；

the second node broadcasts the configured system information in the at least one cell according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The first node of claim 27, wherein:

the content of the message includes configured system information for the at least one cell；

the second node receives, from a user equipment in the at least one cell, an on-demand request for a portion of the configured system information； and

the second node broadcasts the portion of the configured system information to the user equipment according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The first node of claim 27, wherein:

the content of the message includes reconfigured system information for the at least one cell；

the first node further comprises a paging generator configured to generate a paging message when the response indicates the content of the message is successfully obtained by the second node, the paging message indicating a modification of the system information； and

the transmitter is further configured to send, via the second node, the paging message in the at least one cell.
The first node of claim 30, wherein:

the second node broadcasts the reconfigured system information in the at least one cell according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The first node of claim 30, wherein:

the second node receives, from a user equipment in the at least one cell, an on-demand request for a portion of the reconfigured system information； and

the second node broadcasts the portion of the reconfigured system information to the user equipment according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The first node of claim 25, wherein the system information comprises at least one of:

an identification of the at least one cell；

a separately encoded container for each system information element of the system information；

scheduling information；

indication information indicating whether each system information element is to be sent to user equipments in the at least one cell by broadcasting or on-demand；

an indication of system information acquiring scheme, indicating whether each system information element or each system information element combination is to be acquired by user equipment via Msg1, Msg3, or a combination of Msg1 and Msg3；

a mapping relationship between random access channel resources and system information blocks, wherein the random access channel resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and

configuration parameter information related to system information reconfiguration.
The first node of claim 25, wherein the system information comprises at least one of:

a modification period indicating an effective time when the system information will be modified, wherein the modification period is calculated and indicated by the first node； and

one or more parameters to be utilized for calculating the modification period by the second node.
The first node of claim 34, wherein the one or more parameters are carried in the message.
The first node of claim 34, wherein the one or more parameters are indicated by a physical layer indication message related to cell setup.
A first node, comprising:

a receiver configured to receive, from a second node, a message related to system information that is associated with at least one cell in a wireless network, wherein the first node and the second node cooperate to serve the at least one cell as a base station； and

a transmitter configured to transmit a response to the second node, wherein the response indicates whether content of the message is successfully obtained by the first node or not.
The first node of claim 37, wherein:

the first node is a distributed unit of the base station； and

the second node is a centralized unit of the base station.
The first node of claim 37, wherein the system information comprises at least one of: minimum system information that is required for each user equipment in the at least one cell, and other system information.
The first node of claim 37, wherein:

the content of the message includes configured system information for the at least one cell； and

the first node further comprises a system information broadcaster configured to broadcast the configured system information in the at least one cell according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The first node of claim 37, wherein:

the content of the message includes configured system information for the at least one cell；

the receiver is further configured to receive, from a user equipment in the at least one cell, an on-demand request for a portion of the configured system information, and

the first node further comprises a system information broadcaster configured to broadcast the portion of the configured system information to the user equipment according to scheduling information in the configured system information, after successfully obtaining the content of the message.
The first node of claim 37, wherein:

the content of the message includes reconfigured system information for the at least one cell；

the receiver is further configured to receive a paging message from the second node when the response indicates the content of the message is successfully obtained by the first node, the paging message indicating a modification of the system information； and

the first node further comprises a paging forwarding unit configured to send the paging message in the at least one cell.
The first node of claim 42, further comprising:

a system information broadcaster configured to broadcast the reconfigured system information in the at least one cell according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The first node of claim 42, wherein:

the receiver is further configured to receive, from a user equipment in the at least one cell, an on-demand request for a portion of the reconfigured system information； and

the first node further comprises a system information broadcaster configured to broadcast the portion of the reconfigured system information to the user equipment according to scheduling information in the reconfigured system information, after successfully obtaining the content of the message.
The first node of claim 37, wherein the system information comprises at least one of:

an identification of the at least one cell；

a separately encoded container for each system information element of the system information；

scheduling information；

indication information indicating whether each system information element is to be sent to user equipments in the at least one cell by broadcasting or on-demand；

an indication of system information acquiring scheme, indicating whether each system information element or each system information element combination is to be acquired by user equipment via Msg1, Msg3, or a combination of Msg1 and Msg3；

a mapping relationship between random access channel resources and system information blocks, wherein the random access channel resources comprise resources in at least one of: time domain, frequency domain, code domain, and power domain； and

configuration parameter information related to system information reconfiguration.
The first node of claim 37, wherein the system information comprises at least one of:

a modification period indicating an effective time when the system information will be modified, wherein the modification period is calculated and indicated by the second node； and

one or more parameters to be utilized for calculating the modification period by the first node.
The first node of claim 46, wherein the one or more parameters are carried in the message.
The first node of claim 46, wherein the one or more parameters are indicated by a physical layer indication message related to cell setup.