EP-4736566-A1 - METHODS, DEVICES, AND COMPUTER READABLE STORAGE MEDIUM FOR TWO-STAGE RANDOM ACCESS

Abstract

Example embodiments relate to methods, devices and a computer readable storage medium for two-stage RA. In an aspect, a first network device receives RA preambles from devices. The first network device transmits, based on the received RA preambles, a group RA request to a second network device. The group RA request indicating that the devices attempt to establish connections with the second network device. In this way, power consumption of the devices due to sending uplink UL information may be reduced. In addition, the probability of missed detection of RA preambles by the second network device may be reduced.

Inventors

• JASSAL, Aman
• MAAREF, AMINE
• MA, JIANGLEI

Assignees

• Huawei Technologies Co., Ltd.

Dates

Publication Date

20260506

Application Date

20240318

Claims (20)

1. A method for communications, comprising: receiving, at a first network device, random access (RA) preambles from devices; and transmitting, based on the received RA preambles, a group RA request to a second network device, the group RA request indicating that the devices attempt to establish connections with the second network device.
2. The method of claim 1, further comprising: receiving, from the devices, requests for establishing the connections; and transmitting a group connection setup request to the second network device, the group connection setup request comprising at least part of the requests received from the devices.
3. The method of claim 1, further comprising: determining a first plurality of random access channel (RACH) identities (IDs) based on at least one physical random access channel (PRACH) occasion in which the RA preambles were received; and wherein the group RA request comprises the first plurality of RACH IDs.
4. The method of claim 1, 2 or 3, wherein the group RA request indicates at least one of the following: time when the RA preambles were received, types of the devices, whether a timing advance field is to be included in an RA response, wherein the RA response is to be received from the second network device, whether a frequency hopping field is to be included in the RA response, whether an uplink frequency resource allocation field is to be included in the RA response, whether an uplink time resource allocation field is to be included in the RA response, whether a modulation and coding scheme (MCS) field is to be included in the RA response, whether a Transmit Power Control (TPC) command is to be included in the RA response, whether a channel state information (CSI) request field is to be included in the RA response, whether a channel access cyclic prefix (CP) extension field is to be included in the RA response, whether an azimuth beam angle information (BAI) field is to be included in the RA response, whether a zenith BAI field is to be included in the RA response, or whether a temporary cell radio network temporary identifier (C-RNTI) field is to be included in the RA response.
5. The method of claim 1, further comprising: obtaining a configuration for the group RA request.
6. The method of claim 5, wherein the configuration for the group RA request indicates at least one of the following: a time window for reception of the RA preambles, a period of the time window, a length of sequences of the RA preambles, time resources on which the RA preambles are to be received, frequency resources on which the RA preambles are to be received, whether time when the RA preambles were received is to be included in the group RA request, whether types of the devices is to be included in the group RA request, whether a timing advance request field is to be included in the group RA request, whether a frequency hopping field is to be included in the group RA request, whether an uplink frequency resource allocation field is to be included in the group RA request, whether an uplink time resource allocation field is to be included in the group RA request, whether a modulation and coding scheme (MCS) field is to be included in the group RA request, whether a Transmit Power Control (TPC) command is to be included in the group RA request, whether a channel state information (CSI) request field is to be included in the group RA request, whether a channel access cyclic prefix (CP) extension field is to be included in the group RA request, whether an azimuth beam angle information (BAI) field is to be included in the group RA request, whether a zenith BAI field is to be included in the group RA request, or whether a temporary cell radio network temporary identifier (C-RNTI) field is to be included in the group RA request.
7. The method of claim 2, wherein the group connection setup request comprises at least one of the following: a second plurality of identities (IDs) of the devices, or types of services that triggered establishment of the connections.
8. The method of claim 1, wherein the RA preambles are comprised in a first group of RA preambles which are associated with a non-terrestrial network.
9. The method of claim 1, wherein the first network device is included in a terrestrial network and the second network device is included in a non-terrestrial network.
10. The method of claim 1, wherein the first network device and the second network device are included in a non-terrestrial network.
11. A method for communications, comprising: receiving a group random access (RA) request at a second network device from a first network device, the group RA request indicating that devices attempt to establish connections with the second network device; and transmitting an RA response to at least one of the devices.
12. The method of claim 11, further comprising: receiving a group connection setup request from the first network device, the group connection setup request comprising at least part of requests for establishing the connections which were transmitted by the devices; and transmitting a connection setup response to at least one of the devices.
13. The method of claim 11, wherein the group RA request comprises a first plurality of random access channel (RACH) identities (IDs) of the devices.
14. The method of claim 13, wherein the RA response comprises downlink control information scrambled with one of the first plurality of RACH IDs of the devices.
15. The method of claim 11, 12, 13 or 14, wherein the group RA request indicates at least one of the following: time when RA preambles were received by the first network device, types of the devices, whether a timing advance field is to be included in the RA response message, whether a frequency hopping field is to be included in the RA response message, whether an uplink frequency resource allocation field is to be included in the RA response message, whether an uplink time resource allocation field is to be included in the RA response message, whether a modulation and coding scheme (MCS) field is to be included in the RA response message, whether a Transmit Power Control (TPC) command is to be included in the RA response message, whether a channel state information (CSI) request field is to be included in the RA response message, whether a channel access cyclic prefix (CP) extension field is to be included in the RA response message, whether an azimuth beam angle information (BAI) field is to be included in the RA response message, whether a zenith BAI field is to be included in the RA response message, or whether a temporary cell radio network temporary identifier (C-RNTI) field is to be included in the RA response message.
16. The method of claim 11, further comprising: transmitting, to the first network device, a configuration for the group RA request.
17. The method of claim 16, wherein the configuration for the group RA request indicates at least one of the following: a time window for reception of RA preambles, a period of the time window, a length of sequences of the RA preambles, time resources on which the RA preambles are to be received, frequency resources on which the RA preambles are to be received, whether time when the RA preambles were received is to be included in the group RA request, whether types of the devices is to be included in the group RA request, whether a timing advance request field is to be included in the group RA request, whether a frequency hopping field is to be included in the group RA request, whether an uplink frequency resource allocation field is to be included in the group RA request, whether an uplink time resource allocation field is to be included in the group RA request, whether a modulation and coding scheme (MCS) field is to be included in the group RA request, whether a Transmit Power Control (TPC) command is to be included in the group RA request, whether a channel state information (CSI) request field is to be included in the group RA request, whether a channel access cyclic prefix (CP) extension field is to be included in the group RA request, whether an azimuth beam angle information (BAI) field is to be included in the group RA request, whether a zenith BAI field is to be included in the group RA request, or whether a temporary cell radio network temporary identifier (C-RNTI) field is to be included in the group RA request.
18. The method of claim 12, wherein the group connection setup request comprises at least one of the following: a second plurality of identities (IDs) of the devices, or types of services that triggered establishment of the connections between the second network device and the devices.
19. The method of claim 11, wherein the first network device is included in a terrestrial network and the second network device is included in a non-terrestrial network.
20. The method of claim 11, wherein the first network device and the second network device are included in a non-terrestrial network.

Description

METHODS, DEVICES, AND COMPUTER READABLE STORAGE MEDIUM FOR TWO-STAGE RANDOM ACCESS CORSS-REFERENCES TO RELATED APPLICATIONS This application claims the benefit and priority to U.S. Patent Application No. 63/588,151 filed on October 5, 2023, the content of which is incorporated herein by reference in its entirety. FIELD Example embodiments of the present disclosure relates generally to wireless communications. Particularly, it relates to methods, devices, and computer readable storage medium for two-stage random access (RA) . BACKGROUND Wireless communications system such as fourth generation (4G) system (for example, Long-Term Evolution (LTE) system) , fifth generation (5G) system (for example, New Radio (NR) system) have been deployed to provide various types of applications, such as message, voice, video and other data. In NR, non-terrestrial networks (NTNs) are developed, which may utilize spaceborne vehicles such as satellites (including low earth orbiting (LEO) satellites, medium earth orbiting (MEO) satellites, geostationary earth orbiting (GEO) satellites as well as highly elliptical orbiting (HEO) satellites) , or airborne vehicles (also called high-altitude platform) such as drones, or aircraft as a base station or relay for communications between different devices. Either the satellites or the drones in NTNs may move at a high-speed relative to devices such as user equipments (UEs) operating within the NTN, which is different from the scenario between UE and ground-based base station. In addition, the distance between the UE and the satellites or the drones is also much longer then the distance between UE and ground-based base station. Accordingly, solutions in NTNs, which may cooperate with terrestrial networks (TN) , to provide communications with acceptable cost (such as power consumption, and or complexity) are desired. SUMMARY In general, example embodiments of the present disclosure provide a solution for two-stage random access. It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. In a first aspect, there is provided a method performed by a first network device. The method comprises: receiving, at a first network device, RA preambles from devices; and transmitting, based on the received RA preambles, a group RA request to a second network device, the group RA request indicating that the devices attempt to establish connections with the second network device. In this way, power consumption of the devices due to sending uplink UL information may be reduced. In addition, the probability of missed detection of RA preambles by the second network device may be reduced. In some implementations of the present disclosure, the method further comprises: receiving, from the devices, requests for establishing the connections; and transmitting a group connection setup request to the second network device, the group connection setup request comprising at least part of the requests received from the devices. In this way, it is more feasible for the first network device to process RA requests from the devices on the ground and also initiate or establish RRC connections for the devices. In some implementations of the present disclosure, the method further comprises: determining a first plurality of random access channel (RACH) identities (IDs) based on at least one physical random access channel (PRACH) occasion in which the RA preambles were received. The group RA request comprises the first plurality of RACH IDs. In some implementations of the present disclosure, the group RA request indicates at least one of the following: time when the RA preambles were received; types of the devices; whether a timing advance field is to be included in an RA response, wherein the RA response is to be received from the second network device; whether a frequency hopping field is to be included in the RA response; whether an uplink frequency resource allocation field is to be included in the RA response; whether an uplink time resource allocation field is to be included in the RA response; whether a modulation and coding scheme (MCS) field is to be included in the RA response; whether a Transmit Power Control (TPC) command is to be included in the RA response; whether a channel state information (CSI) request field is to be included in the RA response; whether a channel access cyclic prefix (CP) extension field is to be included in the RA response; whether an azimuth beam angle information (BAI) field is to be included in the RA response; whether a zenith BAI field is to be included in the RA response; or whether a temporary cell radio network temporary identifier (C-RNTI) field is to be included in the RA response. In some implementations of the prese