JP2019068150A - Radio communication device - Google Patents

Abstract

The present invention provides a wireless communication apparatus capable of suppressing the amount of data required for NACK_SN notification regardless of the multiplexing method of RLC PDUs to MAC PDUs. A UE transmits and receives protocol data units in an RLC layer. The UE 100 includes a status report transmission unit 140 that generates a status report indicating reception status in the RLC layer and transmits the status report. The status report includes a field of bitmap that indicates the reception status of the protocol data unit by bits. [Selected figure] Figure 2

Description

  The present invention relates to a wireless communication apparatus that transmits and receives protocol data units in a wireless link control layer.

  The 3rd Generation Partnership Project (3GPP) has specified Long Term Evolution (LTE) and specified LTE-Advanced (hereinafter referred to as LTE including LTE-Advanced) in order to further accelerate LTE. Further, in 3GPP, a specification of a successor system of LTE called 5G New Radio (NR) or the like is further studied.

  The configuration of the protocol data unit (RLC PDU) of the radio link control layer (RLC layer) has been discussed in the specification study of such an NR (for example, Non-Patent Document 1).

  Also, according to the operation in the RLC layer of NR, the sequence number (NACK_SN) of the negative acknowledgment (NACK) included in the status report of the RLC layer is increased, so a method of suppressing the number of NACK_SNs is also discussed For example, Non Patent Literature 2).

  Specifically, the NACK range field in the status report of the RLC layer is the number of service data units (RLC SDU) of the RLC layer lost continuously, and is defined as including NACK_SN. There is. This can reduce the amount of data in the NACK range field substantially.

“Further design aspects of the NR User Plane stack”, R2-1700429, 3GPP TSG-RAN WG2 Meeting NR ad-hoc, 3GPP, January 2017 “Discussion on the format of NR RLC status PDU”, R2-1702941, 3GPP TSG-RAN 2 Meeting # 97 bis, 3 GPP, April 2017

  However, the sequence numbers of RLC PDUs multiplexed into PDUs (MAC PDUs) of the medium access control layer may not necessarily be consecutive. Therefore, in the definition of the NACK range field as described above, there may occur a case where the number of NACK_SNs can not be effectively suppressed.

  Therefore, the present invention has been made in view of such a situation, and provides a wireless communication apparatus capable of suppressing the amount of data necessary for NACK_SN notification regardless of the multiplexing method of RLC PDUs to MAC PDUs. To aim.

  One aspect of the present invention is a wireless communication apparatus (for example, UE 100) that transmits and receives a protocol data unit (RLC PDU) in a wireless link control layer, and a status report (RLC STATUS) indicating a reception status in the wireless link control layer. A status report transmitting unit (status report transmitting unit 140) for generating a PDU) and transmitting the status report, wherein the status report includes a bit map field indicating the reception status of the protocol data unit by a bit It is a summary.

  According to the above-described wireless communication apparatus, the amount of data necessary for NACK_SN notification can be suppressed regardless of the multiplexing method of RLC PDUs to MAC PDUs.

FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10. FIG. 2 is a functional block configuration diagram of the UE 100. As shown in FIG. FIG. 3 is a diagram showing an example of multiplexing of RLC PDU 300 on MAC PDU 250. FIGS. 4A and 4B are diagrams showing a configuration example (configuration example 1) of the RLC STATUS PDU. FIG. 5 is a diagram showing a configuration example (configuration example 2) of the RLC STATUS PDU. FIG. 6 is a diagram showing a configuration example (configuration example 3) of the RLC STATUS PDU. FIG. 7 is a diagram illustrating a configuration example (configuration example 4) of the RLC STATUS PDU. FIG. 8 is a diagram illustrating an example of a hardware configuration of the UE 100.

  Hereinafter, embodiments will be described based on the drawings. In addition, the same or similar reference numerals are given to the same functions or configurations, and the description thereof will be appropriately omitted.

(1) Overall Schematic Configuration of Wireless Communication System FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10 according to the present embodiment. As shown in FIG. 1, the wireless communication system 10 is a wireless communication system according to 5G New Radio (NR). The radio communication system 10 includes a radio access network 20, a user apparatus 100 (hereinafter, UE 100), and a radio base station 200 (hereinafter, gNB 200).

  The radio access network 20 is a Radio Access Network defined in the 3rd Generation Partnership Project (3GPP), and includes gNB 200.

  The UE 100 and the gNB 200 perform wireless communication according to the NR specification. In particular, in the present embodiment, the UE 100 and the gNB 200 transmit and receive protocol data units (MAC PDU and RLC PDU) in the medium access control layer (MAC layer) and the radio link control layer (RLC layer). Only RLC PDUs are shown in FIG.

  Moreover, UE100 and gNB200 transmit / receive the status report which reports the reception condition in a RLC layer.

(2) Functional Block Configuration of Mobile Communication System Next, a functional block configuration of the wireless communication system 10 will be described. FIG. 2 is a functional block configuration diagram of the UE 100. As shown in FIG. As shown in FIG. 2, the UE 100 includes a radio communication unit 110, an RLC layer processing unit 120, a MAC layer processing unit 130, and a status report transmission unit 140. The gNB 200 also has substantially the same functions as the UE 100 with respect to the MAC layer and the RLC layer.

  The wireless communication unit 110 performs wireless communication in accordance with the NR scheme. Specifically, the wireless communication unit 110 transmits and receives wireless signals according to the NR scheme with the gNB 200. User data or control data is multiplexed to the radio signal. Also, control data is transmitted and received by messages of the radio resource control layer (RRC layer).

  The RLC layer processing unit 120 executes processing in the RLC layer. Specifically, the RLC layer processing unit 120 constructs an RLC PDU from the RLC SDU, transmits it to the MAC layer processing unit 130, and executes the reverse processing.

  The MAC layer processing unit 130 executes processing in the MAC layer. Specifically, the MAC layer processing unit 130 constructs a MAC PDU from a MAC SDU including an RLC PDU, transmits it to the physical layer, and executes the reverse process.

  The status report transmission unit 140 generates a status report indicating the reception status in the RLC layer. Specifically, the status report transmission unit 140 monitors the reception status of RLC PDU (whether or not the RLC PDU is normally received) in the RLC layer processing unit 120, and an acknowledgment (ACK) or a non-acknowledgement (NACK). Generate

  The status report transmission unit 140 generates a status report including ACK and NACK sequence numbers (SNs), specifically, an RLC STATUS PDU. The status report transmission unit 140 transmits the generated RLC STATUS PDU to the MAC layer processing unit 130. The RLC STATUS PDU is also included in the MAC PDU and sent to the gNB 200.

(3) Operation of Radio Communication System Next, the operation of the radio communication system 10 will be described. Specifically, the transmission operation of the RLC PDU (including the RLC STATUS PDU) by the UE 100 will be described.

(3.1) Example of multiplexing RLC PDU on MAC PDU FIG. 3 shows an example of multiplexing RLC PDU 300 on MAC PDU 250. As shown in FIG. 3, a plurality of RLC PDUs 300 are multiplexed in the MAC PDU 250. In the example illustrated in FIG. 3, MAC PDU # 1 includes three RLC PDUs 300. The sequence numbers (SNs) of the RLC PDUs 300 included in the MAC PDU # 1 are 0, 2, 4 (that is, discontinuous).

  Similarly, MAC PDU # 2 includes three RLC PDUs 300. The sequence numbers (SNs) of the RLC PDUs 300 included in the MAC PDU # 2 are 1, 3, 5 (that is, discontinuous).

  As described above, since the relationship between the MAC PDU 250 and the SN of the RLC PDU 300 is not particularly limited, the SN of the RLC PDU 300 multiplexed to the MAC PDU 250 may not be continuous. Therefore, in such a case, the RLC PDU 300 included in the MAC PDU 250 must be lost and a negative acknowledgment (NACK) must be sent, but in the NACK range field definition as described above, the number of NACK_SNs is effectively reduced. There is a possibility that it can not be suppressed.

  Therefore, in the present embodiment, a method of suppressing the number of NACK_SNs even in the case shown in FIG. 3 is provided by the configuration of RLC PDU (RLC STATUS PDU) as shown below.

(3.2) Configuration Example of RLC PDU (RLC STATUS PDU) Next, regarding a configuration example of RLC PDU according to the present embodiment, specifically, RLC STATUS PDU (may be referred to simply as STATUS PDU) explain.

(3.2.1) Configuration example 1
FIGS. 4A and 4B show configuration examples (configuration example 1) of RLC STATUS PDU. Specifically, FIG. 4 (a) shows the entire configuration of the RLC STATUS PDU 310, and FIG. 4 (b) shows a configuration example of the ACK NACK bitmap included in the RLC STATUS PDU 310. As shown in FIG.

  The RLC STATUS PDU 310 shown in FIG. 4 (a) is based on the configuration shown in Chapter 6.2.1.5 of the 3GPP Draft TS 38.322. As shown in FIG. 4A, the field of the ACK NACK bitmap replaces the NACK range field defined in the Draft TS 38.322.

  In Configuration Example 1, a fixed-length ACK NACK bitmap is used. If the ACK NACK bitmap can not include all target SNs (NACK_SNs), ACK NACK bitmaps of another RLC STATUS PDU may be used. When using another RLC STATUS PDU, it is preferable to notify that a subsequent bit map exists in a specific field. For example, the position of "R" after "E3" shown in FIG. 4A can be used. Alternatively, a new value may be defined as Control PDU Type (CPT).

  Alternatively, similar NACK_SN and ACK NACK bitmap may be repeated again.

  The bit map shown in FIG. 4 (b) includes the first NACK_SN, and indicates the reception status of RLC PDUs after the NACK_SN as 0 (NG) or 1 (OK).

(3.2.2) Configuration example 2
FIG. 5 shows a configuration example (configuration example 2) of the RLC STATUS PDU. Hereinafter, differences from the configuration example 1 will be mainly described. As shown in FIG. 5, in the RLC STATUS PDU 311, a variable-length ACK NACK bitmap is used. For this reason, a field of Length of bitmap indicating the length of the ACK NACK bitmap is provided.

  The other configuration of the RLC STATUS PDU 311 is similar to that of the RLC STATUS PDU 310.

(3.2.3) Configuration example 3
FIG. 6 shows a configuration example (configuration example 3) of the RLC STATUS PDU. Hereinafter, differences from the configuration example 1 will be mainly described. As shown in FIG. 6, in the RLC STATUS PDU 320, in addition to the ACK NACK bitmap, it is notified whether or not a pair of start (end) and end (end) of segment offset (SO) of an Acknowledged Mode (AMD) PDU continues. A field of SO presence bitmap is provided. As the SO presence bitmap, a bitmap having a length similar to that of the ACK NACK bitmap may be prepared, or a bitmap for RLC SDU reported as a NACK SN (not received) in the ACK NACK bitmap may be prepared. For example, if the RLC SDU (PDU) corresponding to the first bit in the ACK NACK bitmap has not been received and notification of SOstart and SOend is required, the corresponding bit in the SO presence bitmap is notified as 1, and otherwise Will be notified as 0.

(3.2.4) Configuration example 4
FIG. 7 shows a configuration example (configuration example 4) of the RLC STATUS PDU. RLC STATUS PDU 321 shown in FIG. 7 uses variable-length ACK NACK bitmap in RLC STATUS PDU 320 according to Configuration Example 3. For this reason, fields of Length of bitmap and SO presence bitmap are provided. The method of notification is the same as in Configuration Example 3.

(4) Operation / Effect According to the above-described UE 100 (and gNB 200), the number (bit number) of NACK_SNs included in the RLC STATUS PDU can be reduced by using the ACK NACK bitmap. By this means, regardless of the multiplexing method of RLC PDUs to MAC PDUs, it is possible to suppress the amount of data required for NACK_SN notification.

(5) Other Embodiments The contents of the present invention have been described above according to the embodiments, but the present invention is not limited to these descriptions, and various modifications and improvements are possible. It is obvious to the trader.

  For example, in the above embodiment, the reduction of NACK_SN in the radio link control layer (RLC layer) has been described, but the present invention may be applied to layers other than the RLC layer.

  In addition, the UE 100 and the gNB 200 may be notified and shared that they have the ability to reduce NACK_SN, that is, whether they correspond to the processing used by the ACK NACK bitmap.

  Furthermore, the reduction of NACK_SN described above may be applied to modes other than RLC-AM (Acknowledged Mode) (for example, Unacknowledged Mode (UM)).

  Further, the block configuration diagram (FIG. 2) used in the description of the embodiment described above shows functional blocks. These functional blocks (components) are realized by any combination of hardware and / or software. Moreover, the implementation means of each functional block is not particularly limited. That is, each functional block may be realized by one physically and / or logically coupled device, or directly and / or indirectly two or more physically and / or logically separated devices. It connects (for example, wired and / or wirelessly), and may be realized by a plurality of these devices.

  Furthermore, the UE 100 described above may function as a computer that performs the process of the present invention. FIG. 8 is a diagram showing an example of the hardware configuration of the device. As shown in FIG. 8, the device may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007 and the like.

  Each functional block (see FIG. 2) of the UE 100 is realized by any hardware element of the computer apparatus or a combination of the hardware elements.

  The processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like.

The memory 1002 is a computer readable recording medium, and may be, for example, a ROM (Read).
The memory may be configured of at least one of an Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), and a RAM (Random Access Memory). The memory 1002 may be called a register, a cache, a main memory (main storage device) or the like. The memory 1002 can store a program (program code) capable of executing the method according to the above-described embodiment, a software module, and the like.

  The storage 1003 is a computer readable recording medium, and for example, an optical disc such as a CD-ROM (Compact Disc ROM), a hard disc drive, a flexible disc, a magneto-optical disc (eg, a compact disc, a digital versatile disc, a Blu-ray A (registered trademark) disk, a smart card, a flash memory (for example, a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, and the like may be used. The storage 1003 may be called an auxiliary storage device. The above-mentioned recording medium may be, for example, a database including the memory 1002 and / or the storage 1003, a server or other appropriate medium.

  The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via a wired and / or wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, or the like.

  The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, and the like) that receives an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may be integrated (for example, a touch panel).

  Also, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured by a single bus or may be configured by different buses among the devices.

  In addition, notification of information is not limited to the above-described embodiment, and may be performed by another method. For example, notification of information may be physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (for example, RRC signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (for example)). Master Information Block), SIB (System Information Block), other signals, or a combination of these, or RRC signaling may be referred to as an RRC message, eg, RRC Connection Setup message, RRC It may be a Connection Reconfiguration message or the like.

  Furthermore, the input / output information may be stored in a specific place (for example, a memory) or may be managed by a management table. Information to be input or output may be overwritten, updated or added. The output information may be deleted. The input information may be transmitted to another device.

  The sequences, flowcharts, and the like in the above-described embodiments may be rearranged as long as there is no contradiction.

  Also, in the above-described embodiment, the specific operation performed by the gNB 200 may be performed by another network node (device). Also, the function of the gNB 200 may be provided by a combination of a plurality of other network nodes.

  The terms described in the present specification and / or the terms necessary for the understanding of the present specification may be replaced with terms having the same or similar meanings. For example, the channels and / or symbols may be signals, where relevant. Also, the signal may be a message. Also, the terms "system" and "network" may be used interchangeably.

  Furthermore, the parameter or the like may be represented by an absolute value, may be represented by a relative value from a predetermined value, or may be represented by another corresponding information. For example, radio resources may be indexed.

  The gNB 200 (base station) can accommodate one or more (eg, three) cells (also called sectors). If the base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small base station RRH for indoor use: Remote Communication service can also be provided by Radio Head.

  The terms "cell" or "sector" refer to a portion or all of the coverage area of a base station and / or a base station subsystem serving communication services in this coverage. Furthermore, the terms "base station" "eNB", "cell" and "sector" may be used interchangeably herein. A base station may also be called in terms of a fixed station (Node station), NodeB, eNodeB (eNB), gNodeB (gNB), access point (access point), femtocell, small cell, and so on.

  The UE 100 can be a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal by a person skilled in the art , Remote terminal, handset, user agent, mobile client, client, or some other suitable term.

  As used herein, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

  Also, the terms "including," "comprising," and variations thereof are intended to be inclusive as well as "comprising." Furthermore, it is intended that the term "or" as used in the present specification or in the claims is not an exclusive OR.

  Any reference to an element using the designation "first," "second," etc. as used herein does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient way of distinguishing between two or more elements. Thus, reference to the first and second elements does not mean that only two elements can be taken there, or that in any way the first element must precede the second element.

  Throughout the present specification, when articles are added by translation, such as a, an, and the in English, for example, these articles are not clearly indicated by the context. , Including several things.

  While the embodiments of the present invention have been described above, it should not be understood that the statements and drawings that form a part of this disclosure limit the present invention. Various alternative embodiments, examples and operation techniques will be apparent to those skilled in the art from this disclosure.

10 Wireless Communication System
20 Wireless Access Network
100 UE
110 Wireless Communication Unit
120 RLC layer processing unit
130 MAC layer processing unit
140 Status report transmitter
200 gNB
250 MAC PDU
300 RLC PDU
310, 311, 320, 321 RLC STATUS PDU
1001 processor
1002 memory
1003 storage
1004 Communication device
1005 input device
1006 output device
1007 bus

Claims (3)

A wireless communication apparatus for transmitting and receiving protocol data units in a wireless link control layer, comprising:
A status report transmission unit that generates a status report indicating reception status in the radio link control layer and transmits the status report;
The wireless communication device, wherein the status report includes a bit map field indicating the reception status of the protocol data unit by bits.   The wireless communication apparatus according to claim 1, wherein the bit included in the bitmap indicates whether a protocol data unit has been successfully received. The fields of the bitmap are of variable length,
The wireless communication apparatus according to claim 1, wherein the status report includes information indicating a field length of a bitmap.

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