CN113543352B

CN113543352B - Random access response determination method, device and system

Info

Publication number: CN113543352B
Application number: CN202110796704.4A
Authority: CN
Inventors: 王宏勇; 武传国; 是元吉
Original assignee: Shanghai Qingkun Information Technology Co Ltd
Current assignee: Shanghai Qingkun Information Technology Co Ltd
Priority date: 2021-07-14
Filing date: 2021-07-14
Publication date: 2023-05-30
Anticipated expiration: 2041-07-14
Also published as: CN113543352A

Abstract

The invention relates to a random access response determining method, a device and a system. When the MAC sub PDUs of the RAPID type in the random access response MAC PDU all carry the MAC RAR, the user terminal can acquire the information through the newly added domain I, and the method can determine whether the MAC RAR is contained or not without searching the RAPIID of each MAC sub PDU in the preamble set, thereby improving the efficiency of analyzing the random access response MAC PDU. The invention uses one reserved bit in the random access response MAC PDU in the existing NR protocol, is completely compatible with the existing network, does not affect gNB and UE which do not realize the function, and is very simple to realize and easy to implement.

Description

Random access response determination method, device and system

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, an apparatus, and a system for determining a random access response.

Background

Random access can be classified into competitive random access and non-competitive random access. The contention random access procedure is shown in fig. 1, and generally includes the following four steps:

1) MSG1: a User Equipment (UE) determines a physical random access channel (Physical Random Access Channel, PRACH) resource and a random access preamble, sends MSG1 to a NR base station (gnnode B, gNB), and notifies the gNB of a random access request.

2) MSG2: and the gNB transmits MSG2 to the UE, wherein the MSG2 contains timing advance information and subsequent uplink resource allocation information. In addition, the MSG2 also carries a random access preamble sequence identifier (Random Access Preamble Identity, RAPID), and the UE determines that the MSG2 corresponds to the MSG1 transmitted by the UE through the RAPID.

3) MSG3: after receiving the MSG2, the UE judges that the MSG2 carries the RAPID corresponding to the preamble when sending the MSG1, and sends the MSG3 to the gNB.

4) MSG4: the gNB sends MSG4 to the UE, and the UE can judge whether the random access is successful or not according to the MSG 4.

The non-contention random access procedure is shown in fig. 2, and includes the following three steps:

1) MSG0: the gNB allocates random access preamble and PRACH resources for non-contention for the UE.

2) MSG1: and the UE sends MSG1 by using the random access preamble specified by MSG0 and PRACH resources, and informs the gNB of a random access request.

3) MSG2: and the gNB transmits MSG2 to the UE, wherein the MSG2 contains timing advance information and subsequent uplink resource allocation information. In addition, the MSG2 also carries a random access preamble identifier RAPID, and the UE determines that the MSG2 corresponds to the MSG1 sent by the UE through the RAPID.

The MSG2 in the above procedure is a response message (Random Access Response) of the random access request of the UE. In a 5G NR network, a protocol data unit (Protocol Data Unit, PDU) of a MAC layer for a random access response is composed of one or more MAC subpdus (possibly including padding), as shown in fig. 3, and information carried by the MAC subpdus is divided into the following three cases:

CASE1: there is only one MAC subheader carrying a back indicator BI (Backoff Indicator).

CASE2: there is only one MAC subheader carrying RAPID.

CASE3: a MAC subheader carrying a RAPID and a MAC RAR.

Both CASE2 and CASE3 contain RAPID, differing in whether MAC RAR is contained. The preambles used by CASE2 and CASE3 are from two different preamble sets, here assuming that the preamble of CASE2 is from set a and the preamble of CASE3 is from set B.

The BI-carrying MAC subheader contains 5 fields: E/T/R/R/BI as shown in FIG. 4. If the subheader is present in the MAC RAR PDU, it should be placed at the beginning of the MAC PDU. The MAC subheader carrying RAPID contains 3 fields: E/T/RAPID, as shown in FIG. 5. The MAC RAR contains the fields as shown in fig. 6. As can be seen from fig. 4 to 6, the MAC sub header occupies one byte and the MAC RAR occupies 7 bytes.

The preamble configured in the cell is divided into two sets, and for the preamble in the set A, the base station does not need to carry the MAC RAR in response; the preamble in set B, the base station needs to carry the MAC RAR in response. Fig. 7 shows a procedure of a UE applying the prior art in parsing a random access response MAC PDU. In step (1) in fig. 7, it is necessary to traverse the preamble list of the cell, and retrieve whether the RAPID carried in the MAC subPDU belongs to the set a or the set B, so as to determine the position of the next MAC subPDU. This search consumes computational resources and time for the UE, and this problem is more pronounced especially for 5G networks, where there are more UEs in the cell.

Disclosure of Invention

The invention aims to provide a method, a device and a system for determining random access response, which can save the processing overhead of UE (user equipment) on the random access response MAC PDU when the random access response MAC PDU contains BI type MAC subPDU and the MAC PDU of the RAID type in the MAC PDU contains MAC RAR.

In order to achieve the above object, the present invention provides the following solutions:

a random access response determination method, comprising:

determining the 3 rd bit position of the MAC subPDU with the header file information of the BI type as an I domain;

when the NR base station transmits the MAC PDU for random access response, if at least one of the header file types of the MAC subPDU in the MAC PDU is not the MAC RAR type, setting the value of the I domain to be 1, otherwise setting the I domain to be 0;

when the user equipment receives the MAC PDU, determining a first MAC sub PDU of the MAC PDU as a current MAC sub PDU;

if the current MAC sub PDU is of BI type and the value of the I domain is 0, determining the MAC RAR of the random access response of the current MAC sub PDU according to the BI type, and determining the MAC RAR of the random access response of each MAC sub PDU by analyzing the MAC sub PDU after the current MAC sub PDU;

if the header file information of the current MAC sub PDU is not of BI type or the value of the I domain of the current MAC sub PDU is 1, determining the MAC RAR of the random access response of each MAC sub PDU in the MAC PDU according to the RAPID type.

Preferably, the determining the MAC RAR of the random access response of each MAC sub-pdu by parsing the MAC sub-pdu after the current MAC sub-pdu specifically includes:

and analyzing the second MAC sub PDU to determine a random access response message of the second MAC sub PDU, and analyzing the third MAC sub PDU until the matching is successful or the last MAC sub PDU is reached when the matching of the type of header information of the second MAC sub PDU and the random response request is unsuccessful and the second MAC sub PDU is not the last MAC sub PDU, and at this time, completing the determination of the MAC RAR of the random access response of each MAC sub PDU after the current MAC sub PDU.

Preferably, before the parsing of the third MAC subPDU, the method further includes:

and skipping the header file analysis of the MAC and the analysis of the MAC RAR in the analysis process.

Preferably, the determining the MAC RAR of the random access response of each MAC sub-PDU in the MAC PDUs according to the RAPID type includes:

when the RAPID type of the current MAC subPDU is not successfully matched with the random response request and the current MAC subPDU is not the last MAC subPDU, traversing all the lead codes to obtain a first set and a second set;

the first set is a preamble set used by the RAPID in the MAC subPDU with only one RAPID type of carried type information;

the second set is a preamble set used by the RAPID type in the MAC subPDU of which the carried type information comprises a MAC RAR and a RAPID type;

judging whether a preamble adopted by the RAPID type of the current MAC sub PDU belongs to the first set or the second set, if the RAPID belongs to the first set, skipping the analysis of the header file of the current MAC to acquire the next MAC sub PDU; if the RAPID belongs to the second set, skipping analysis on the current MAC header file and the MAC RAR to acquire a next MAC sub PDU;

and if the RAPID of the current MAC sub PDU is successfully matched with the random response request, determining the MAC RAR of the current MAC sub PDU as a response message of the random access request.

A random access response determination system, comprising:

the definition module is used for determining the 3 rd bit position of the MAC subPDU with the header file information of the BI type as an I domain;

the assignment module is used for setting the value of the I domain to 1 if at least one of the header file types of the MAC subPDU in the MAC PDU is not the MAC RAR type when the NR base station sends the MAC PDU for random access response, otherwise setting the I domain to 0;

the current position determining module is used for determining a first MAC sub PDU of the MAC PDU as a current MAC sub PDU when the user equipment receives the MAC PDU;

the first analyzing module is configured to determine, if the current MAC sub pdu is of a BI type and the value of the I field is 0, a MAC RAR of a random access response of the current MAC sub pdu according to the BI type, and analyze MAC sub pdus after the current MAC sub pdu to determine the MAC RAR of the random access response of each MAC sub pdu;

and the second parsing module is configured to determine, according to the RAPID type, a MAC RAR of a random access response of each MAC sub PDU in the MAC PDUs if the header file information of the current MAC sub PDU is not a BI type or the value of the I field of the current MAC sub PDU is 1.

Preferably, the first parsing module specifically includes:

a first parsing unit, configured to parse the second MAC pdu to determine a random access response message of the second MAC pdu, and parse the third MAC pdu until the matching is successful or the last MAC pdu is reached when the matching of the type of header information of the second MAC pdu and the random response request is unsuccessful and the second MAC pdu is not the last MAC pdu, and at this time, complete the determination of the MAC RAR of the random access response of each MAC pdu after the current MAC pdu.

Preferably, the second parsing module specifically includes:

and the first analysis subunit is used for skipping the header file analysis of the MAC and the analysis of the MAC RAR in the analysis process.

Preferably, the root second parsing module specifically includes:

a traversing unit, configured to traverse all preambles to obtain a first set and a second set when the RAPID type of the current MAC subPDU is unsuccessful in matching with the random response request and the current MAC subPDU is not the last MAC subPDU; the first set is a preamble set used by the RAPID type in the MAC subPDU with only one RAPID in the carried type information; the second set is a preamble set used by the RAPID type in the MAC subPDU of which the carried type information comprises a MAC RAR and a RAPID type;

a judging unit, configured to judge whether a preamble adopted by a RAPID type of the current MAC sub PDU belongs to the first set or the second set, and if the RAPID belongs to the first set, skip parsing of a header file of the current MAC to obtain a next MAC sub PDU; if the RAPID belongs to the second set, skipping analysis on the current MAC header file and the MAC RAR to acquire a next MAC sub PDU;

a determining unit, configured to determine, if the RAPID of the current MAC subPDU matches with the random response request successfully, a MAC RAR of the current MAC subPDU as a response message of the random access request; if the current MAC subPDU is the last MAC subPDU and the RAPID of the current MAC subPDU is not successfully matched with the random response request, the user equipment shall consider that the random access fails, and decides whether to initiate the random access attempt again or end the random access process according to the maximum number of random access attempts.

An electronic device comprising a processor and a memory, the memory storing an executable computer program, the processor being operable to read the computer program in the memory and to implement a random access response determination method.

A computer readable storage medium storing an executable computer program which when run implements a random access response determination method.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

when the MAC sub PDUs of the RAPID type in the random access response MAC PDU all carry the MAC RAR, the user terminal can acquire the information through the newly added domain I, and whether the MAC RAR is contained or not can be determined without searching the RAPIID of each MAC sub PDU in the preamble set, so that the efficiency of analyzing the random access response MAC PDU is improved, and the processing cost of the UE for the random access response MAC PDU is saved. The invention uses one reserved bit in the random access response MAC PDU in the existing NR protocol, is completely compatible with the existing network, does not affect gNB and UE which do not realize the function, and is very simple to realize and easy to implement.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a diagram of a competitive random access scheme provided in the prior art;

fig. 2 is a schematic diagram of non-contention random access provided in the prior art;

fig. 3 is a schematic diagram of a random access MAC PDU composition provided in the prior art;

FIG. 4 is a schematic diagram of a prior art BI-type MAC sub-header;

FIG. 5 is a schematic diagram of a MAC subheader of the RAPID type in the prior art;

FIG. 6 is a diagram of a domain included in a MAC RAR according to the prior art;

FIG. 7 is a flow chart of a method in an embodiment provided by the present invention;

fig. 8 is a flowchart of processing a random access response MAC PDU in an embodiment provided by the present invention;

FIG. 9 is a schematic diagram of a BI-type MAC subPDU in an embodiment provided by the present invention;

fig. 10 is a flowchart of a conventional random access response MAC PDU processing in an embodiment provided by the present invention;

fig. 11 is a schematic diagram of a random access response MAC PDU composition in an embodiment provided by the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

Fig. 7 and fig. 8 are a flowchart of a method and a flowchart of processing a random access response MAC PDU in an embodiment provided by the present invention, and as shown in fig. 7 and fig. 8, a random access response determining method in this embodiment includes:

s100: and determining the 3 rd bit position of the MAC subPDU with the header file information of the BI type as an I domain.

S200: when the NR base station transmits the MAC PDU for random access response, if at least one of the header file types of the MAC subPDU in the MAC PDU is not the MAC RAR type, the value of the I domain is set to 1, otherwise, the I domain is set to 0.

S300: and when the user equipment receives the MAC PDU, determining the first MAC sub-PDU of the MAC PDU as the current MAC sub-PDU.

S401: if the current MAC sub PDU type is BI type and the value of the I domain is 0, determining the MAC RAR of the random access response of the current MAC sub PDU according to the BI type, and determining the MAC RAR of the random access response of each MAC sub PDU by analyzing the MAC sub PDU after the current MAC sub PDU.

S402: if the header file information of the current MAC sub PDU is not of BI type or the value of the I domain of the current MAC sub PDU is 1, determining the MAC RAR of the random access response of each MAC sub PDU in the MAC PDU according to the RAPID type.

Fig. 9 is a schematic diagram of a BI-type MAC subPDU according to an embodiment of the present invention, and as shown in fig. 9, the present invention modifies the format of the MAC PDU. The 3 rd bit (original reserved bit) of the BI type MAC subPDU in the random access response MAC PDU is taken as a new field and is named as I.

Optionally, when sending the random access response MAC PDU, the gNB side in this embodiment, if the MAC PDU includes a BI type MAC subPDU, then:

(1) If there is at least one MAC sub-PDU without the MAC RAR in the MAC PDU, its I-field is set to 1 in the BI type of MAC sub-PDU.

(2) Otherwise, its I field is set to 0 in the BI-type MAC subPDU.

Specifically, when receiving the random access response MAC PDU, the UE side in this embodiment first parses the first MAC PDU, determines, through its I field, whether there is a MAC PDU without a MAC RAR in the MAC PDU if the first MAC PDU is a BI type MAC PDU, and if I is 0, both the MAC PDUs of the RAPID type include the MAC RAR, and when the RAPID is not matched, directly skips 8 bytes, and then continues parsing the next MAC PDU.

Fig. 10 is a flowchart of processing a random access response MAC PDU according to an embodiment of the present invention, as shown in fig. 10, assuming that a preamble configured in a cell is divided into two sets, for a preamble in set a, a base station does not need to carry a MAC RAR during response; the preamble in set B, the base station needs to carry the MAC RAR in response.

In this embodiment, determining the MAC RAR of the random access response of each MAC subPDU in the MAC PDUs according to the RAPID type includes:

and when the RAPID type of the current MAC sub PDU is not successfully matched with the random response request and the current MAC sub PDU is not the last MAC sub PDU, traversing all the lead codes to obtain a first set and a second set. The first set is set A, and the second set is set B.

The first set is a preamble set used by RAPID in the MAC subPDU with only one RAPID type of carried type information.

The second set is a preamble set used by the RAPID type in the MAC subPDU of the one MAC RAR and one RAPID type, which is carried by the type information.

Judging whether a preamble adopted by the RAPID type of the current MAC sub PDU belongs to the first set or the second set, if the RAPID belongs to the first set, skipping the analysis of the header file of the current MAC to acquire the next MAC sub PDU; and if the RAPID belongs to the second set, skipping the analysis of the current MAC header file and the MAC RAR to acquire the next MAC sub PDU.

Specifically, the field of the BI-type MAC subPDU includes:

e, for indicating whether the MAC subPDU containing the MAC subheader is the last MAC subPDU in the MAC PDU;

t for distinguishing whether BI or RAPID is carried by the MAC sub-header

R, is used for reserving the bit where it is located;

BI, configured to perform random access backoff indication.

Optionally, the MAC RAR comprises any one or more of:

r for setting to reserved bits;

a timing advance instruction, configured to set an uplink timing advance;

at least one UL Grant for resource allocation of subsequent uplink transmission;

at least one sample C-RNTI: for converting into a C-RNTI allocated to the user equipment after completion of contention resolution;

and the contention resolution identity is used for corresponding to the information of the user equipment identifier contained in the random access request of the two-step random access.

When the invention is used in practice:

(1) Assuming that a certain cell C of the gNB is configured with 64 random access preambles with index values from 0 to 63, wherein the preambles with index values from 0 to 31 need to include MAC RAR in their random access response MAC PDUs; the preamble with index values from 32 to 63, the MAC PDUs of their random access responses are MAC RAR-free.

(2) In the cell C, on the same PRACH time-frequency resource, 6 UEs initiate random access requests at the same time, and the preamble index values selected by them are as follows:

UE0：2

UE1：5

UE2：5

UE3：9

UE4：17

UE5：17

it can be seen that 6 UEs initiate random access requests using 4 random access preambles and that these preamble index values are in the range of 0 to 31, i.e. their random access responses all need to contain MAC RARs.

(3) And after the gNB successfully detects 4 random access requests on the PRACH time-frequency resource, the gNB transmits a random access response (MAC) PDU. The random access response MAC PDU includes a BI-type MAC sub PDU and 4 RAPID-type MAC sub, the contents are shown in fig. 11:

the random access response sent by the gNB is successfully received by the 6 UEs (UE 0 to UE 5) in (2), and the 6 UEs perform the following processing:

1.1 6 UEs parse 1 st MAC subPDU from Oct 1, respectively:

t=0, indicating that the type of the MAC sub pdu is BI, and then the value of BI is saved.

I=0, indicating that the MAC subpdus of the RAPID type in the random access response MAC PDU all contain MAC RAR.

E=1, indicating that there are MAC subpdus to be parsed.

1.2 6 UEs parse the 2 nd MAC subPDU from Oct 2:

t=1, indicating that the type of the MAC sub pdu is RAPID.

E=1, indicating that there are MAC subpdus to be parsed.

Rapid=9, indicating that the MAC sub pdu is a response to a UE with a random access preamble index of 9.

UE3: the RAPID is successfully matched, the MAC RAR is saved, and the analysis is ended.

UE0/UE1/UE2/UE4/UE5: the RAPID matching fails and the next MAC subPDU is parsed. Since the MAC subpdus of the RAPID type all contain MAC RAR, it can be determined that the next MAC subPDU starts from Oct 10.

1.3 UE0/UE1/UE2/UE4/UE5 parse the 3 rd MAC subPDU from Oct 10:

t=1, indicating that the type of the MAC sub pdu is RAPID.

E=1, indicating that there are MAC subpdus to be parsed.

Rapid=2, indicating that the MAC sub pdu is a response to a UE with a random access preamble index of 2.

UE0: the RAPID is successfully matched, the MAC RAR is saved, and the analysis is ended.

UE1/UE2/UE4/UE5: the RAPID matching fails and the next MAC subPDU is parsed. Because the MAC subpdus of the RAPID type all contain MAC RAR, it can be determined that the next MAC subPDU starts from Oct 18.

1.4 UE1/UE2/UE4/UE5 parse the 4 th MAC subPDU from Oct 18:

t=1, indicating that the type of the MAC sub pdu is RAPID.

E=1, indicating that there are MAC subpdus to be parsed.

Rapid=5, indicating that the MAC sub pdu is a response to a UE with a random access preamble index of 5.

UE1/UE2: the RAPID is successfully matched, the MAC RAR is saved, and the analysis is ended.

UE4/UE5: the RAPID matching fails and the next MAC subPDU is parsed. Because the MAC subpdus of the RAPID type all contain MAC RAR, it can be determined that the next MAC subPDU starts from Oct 26.

1.5 UE4/UE5 parses the 4 th MAC subPDU from Oct 18:

t=1, indicating that the type of the MAC sub pdu is RAPID.

Rapid=17, indicating that the MAC sub pdu is a response to a UE with a random access preamble index of 17.

UE4/UE5: the RAPID is successfully matched, the MAC RAR is saved, and the analysis is ended.

The invention also provides a random access response determining system, which comprises:

the first analyzing module is configured to determine, if the value of the I field of the current MAC sub pdu is O, a MAC RAR of a random access response of the current MAC sub pdu according to a BI type, and determine, by analyzing a MAC sub pdu subsequent to the current MAC sub pdu, a MAC RAR of a random access response of each MAC sub pdu;

Preferably, the first parsing module specifically includes:

Preferably, the second parsing module specifically includes:

Preferably, the root second parsing module specifically includes:

a determining unit, configured to determine, if the RAPID of the current MAC subPDU matches with the random response request successfully, a MAC RAR of the current MAC subPDU as a response message of the random access request; if the current MAC sub PDU is the last MAC sub PDU and the RAPID of the current MAC sub PDU is not successfully matched with the random response request, the random access fails, and the user equipment judges whether to initiate the random access attempt again or end the random access process according to the maximum number of the random access attempts. .

The invention also provides an electronic device comprising a processor and a memory, the memory storing an executable computer program, the processor being operable to read the computer program in the memory and to implement the random access response determination method of the above embodiments.

The present invention also provides a computer readable storage medium storing an executable computer program, which when run implements the random access response determination method in the above embodiments.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims

1. A method for determining a random access response, comprising:

when an NR base station transmits the MAC PDU for random access response, if at least one MAC RAR type exists in the header file type of the MAC subPDU in the MAC PDU and no header file type is only a RAPID type, setting the value of the I domain to 0, otherwise setting the I domain to 1;

2. The method for determining a random access response according to claim 1, wherein the determining the MAC RAR of the random access response of each MAC sub-pdu by parsing the MAC sub-pdu subsequent to the current MAC sub-pdu specifically includes:

3. The method for determining a random access response according to claim 2, wherein before parsing the third MAC sub pdu, further comprises:

4. The method for determining a random access response according to claim 1, wherein determining a MAC RAR of a random access response of each MAC sub-PDU in the MAC PDUs according to a RAPID type comprises:

5. A random access response determination system, comprising:

the assignment module is used for setting the value of the I domain to 0 if at least one MAC RAR type exists in the header file type of the MAC subPDU in the MAC PDU and the header file type is not existed and is only the RAPID type when the NR base station sends the MAC PDU for random access response, otherwise setting the I domain to 1;

6. The random access response determination system of claim 5, wherein the first parsing module specifically comprises:

7. The random access response determination system of claim 6, wherein the second parsing module specifically comprises:

8. The random access response determination system of claim 5, wherein the second parsing module specifically comprises:

a determining unit, configured to determine, if the RAPID of the current MAC subPDU matches with the random response request successfully, a MAC RAR of the current MAC subPDU as a response message of the random access request; if the current MAC sub PDU is the last MAC sub PDU and the RAPID of the current MAC sub PDU is not successfully matched with the random response request, the random access fails, and the user equipment judges whether to initiate the random access attempt again or end the random access process according to the maximum number of the random access attempts.

9. An electronic device comprising a processor and a memory, the memory storing an executable computer program, the processor being operable to read the computer program in the memory and to implement the random access response determination method as claimed in claim 1.

10. A computer readable storage medium, characterized in that the computer readable storage medium stores an executable computer program, which computer program when run implements the random access response determination method according to claim 1.