# US 12,114,308 B2 · System and method for common control channels in a communications system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,308 B2 - Document ID: US12114308B2 - Status: Granted - Kind: B2 - Application number: 17/493,634 - Filed: 2021-10-04 - Published: 2022-01-27 - Granted: 2024-10-08 - Earliest claimed: 2012-01-30 - Assignees: Futurewei Technologies, Inc. - Applicants: Futurewei Technologies, Inc. - Inventors: Philippe Sartori; Jianghua Liu; Qiang Wu; Vipul Desai; Weimin Xiao; Brian Classon - Web page: https://patentgrep.com/patent/US12114308B2 ## CPC - H04W 72/20: Control channels or signalling for resource management - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04W 24/02: Arrangements for optimising operational condition - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 72/02: Selection of wireless resources by user or terminal - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for operating a communications controller includes selecting a search space configuration out of a set of candidate search space configurations for a user equipment served by the communications controller, wherein the search space configuration specifies one or more search spaces to be monitored out of a set of search spaces, and signaling the selected search space configuration to the user equipment. ## Claims ### Claim 1 A method, comprising: monitoring, by a user equipment (UE), a first search space; receiving, by the UE, configuration information, the configuration information indicating a random access channel (RACH) configuration, the RACH configuration including a first set of preambles and a second set of preambles, wherein the first set of preambles corresponds to the first search space, and the second set of preambles corresponds to a second search space; transmitting, by the UE, a RACH message in accordance with a preamble from the second set of preambles based on a capability of the UE; and monitoring, by the UE, the second search space after the transmitting the RACH message based on the capability of the UE. ### Claim 2 (depends on 1) The method of claim 1, wherein the second search space is a common search space, the monitoring the second search space comprising: monitoring, by the UE, the second search space to receive a second physical downlink control channel (PDCCH) carrying an allocation of a shared channel for a reply to the RACH message. ### Claim 3 (depends on 1) The method of claim 1, wherein the configuration information is broadcasted. ### Claim 4 (depends on 1) The method of claim 1, wherein the first search space is a common search space. ### Claim 5 (depends on 1) The method of claim 1, wherein the RACH message indicates the UE having the capability. ### Claim 6 (depends on 1) The method of claim 1, the monitoring the first search space comprising: monitoring, by the UE, the first search space to receive a first physical downlink control channel (PDCCH) carrying scheduling information, the receiving comprising: receiving, by the UE, the configuration information based on the scheduling information. ### Claim 7 A method, comprising: transmitting, by a base station, a first search space; transmitting, by the base station, configuration information, the configuration information indicating a random access channel (RACH) configuration, the RACH configuration including a first set of preambles and a second set of preambles, wherein the first set of preambles corresponds to the first search space, and the second set of preambles corresponds to a second search space; receiving, by the base station from a user equipment (UE), a RACH message; determining, by the base station, a capability of the UE based on the RACH message; and communicating, by the base station with the UE, in the second search space based on the determining the capability of the UE. ### Claim 8 (depends on 7) The method of claim 7, wherein the second search space is a common search space, the method further comprising: transmitting, by the base station, in the second search space a second physical downlink control channel (PDCCH) carrying an allocation of a shared channel for a reply to the RACH message. ### Claim 9 (depends on 7) The method of claim 7, wherein the configuration information is broadcasted. ### Claim 10 (depends on 7) The method of claim 7, wherein the first search space is a common search space. ### Claim 11 (depends on 7) The method of claim 7, wherein the RACH message indicates the UE having the capability. ### Claim 12 (depends on 7) The method of claim 7, the transmitting the first search space comprising: transmitting, by the base station, in the first search space a first physical downlink control channel (PDCCH) carrying scheduling information, the transmitting the configuration information comprising: transmitting, by the base station, the configuration information based on the scheduling information. ### Claim 13 A user equipment (UE), comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the UE to: monitor a first search space; receive configuration information, the configuration information indicating a random access channel (RACH) configuration, the RACH configuration including a first set of preambles and a second set of preambles, wherein the first set of preambles corresponds to the first search space, and the second set of preambles corresponds to a second search space; transmit a RACH message in accordance with a preamble from the second set of preambles based on a capability of the UE; and monitor the second search space after transmitting the RACH based on the capability of the UE. ### Claim 14 (depends on 13) The UE of claim 13, wherein the second search space is a common search space, the instructions to monitor the second search space comprising instructions to: monitor the second search space to receive a second physical downlink control channel (PDCCH) carrying an allocation of a shared channel for a reply to the RACH message. ### Claim 15 (depends on 13) The UE of claim 13, wherein the configuration information is broadcasted. ### Claim 16 (depends on 13) The UE of claim 13, wherein the first search space is a common search space. ### Claim 17 (depends on 13) The UE of claim 13, wherein the RACH message indicates the UE having the capability. ### Claim 18 (depends on 13) The UE of claim 13, the instructions to cause the UE to monitor the first search space comprising instructions to cause the UE to: monitor the first search space to receive a first physical downlink control channel (PDCCH) carrying scheduling information, the instructions to cause the UE to receive the configuration comprising instructions to cause the UE to: receive the configuration information based on the scheduling information. ### Claim 19 A base station, comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the base station to: transmit in a first search space; transmit configuration information, the configuration information indicating a random access channel (RACH) configuration, the RACH configuration including a first set of preambles and a second set of preambles, wherein the first set of preambles corresponds to the first search space, and the second set of preambles corresponds to a second search space; receive, from a user equipment (UE), a RACH message; determine a capability of the UE based on the RACH message; and communicate, with the UE, in the second search space based on determination of the capability of the UE. ### Claim 20 (depends on 19) The base station of claim 19, wherein the second search space is a common search space, the programming further including instructions that, when executed by the at least one processor, cause the base station to: transmit in the second search space a second physical downlink control channel (PDCCH) carrying an allocation of a shared channel for a reply to the RACH message. ### Claim 21 (depends on 19) The base station of claim 19, wherein the configuration information is broadcasted. ### Claim 22 (depends on 19) The base station claim 19, wherein the first search space is a common search space. ### Claim 23 (depends on 19) The base station of claim 19, wherein the RACH message indicates the UE having the capability. ### Claim 24 (depends on 19) The base station of claim 19, the instructions to cause the base station to transmit the first search space comprising instructions to cause the base station to: transmit in the first search space a first physical downlink control channel (PDCCH) carrying scheduling information, the instructions to cause the base station to transmit the configuration information comprising instructions to cause the base station to: transmit the configuration information based on the scheduling information.