# US 2018/0324871 A1 · Methods and Devices for Random Access > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324871 A1 - Document ID: US20180324871A1 - Status: Published application - Kind: A1 - Application number: 16/039,553 - Filed: 2018-07-19 - Published: 2018-11-08 - Earliest claimed: 2013-08-08 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Rui FAN; Erik ERIKSSON; Xinghua SONG - Web page: https://patentgrep.com/patent/US20180324871A1 ## CPC - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04L 5/14: Two-way operation using the same type of signal, i.e. duplex - H04W 56/001: {Synchronization between nodes} - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 74/0838: using contention-free random access [CFRA] - 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 One embodiment of the present disclosure relates to a method for random access in a UE in an out-of sync status. The method comprises: sending to a base station a first message including a random access preamble according to a TDD configuration in a SIB; receiving from the base station a second message including a random access response using the random access preamble according to the TDD configuration in the SIB. Another embodiment of the present invention also relates to corresponding method for random access in a base station. According to an aspect of the present disclosure, there are provided corresponding devices. ## Claims ### Claim at position 1 -48. (canceled) ### Claim 49 A method for operating a communication device, comprising: sending to a network node device a first message including a random access preamble according to a Time Division Duplex, TDD, configuration in a system information block; receiving from said network node device a second message including a random access response using said random access preamble according to said TDD configuration in said system information block; wherein said communication device is assigned more than one TDD configurations before initiating a random access procedure and said more than one TDD configurations include said TDD configuration in said system information block and further include at least another TDD configuration informed via dedicated Radio Resource Control signaling. ### Claim 50 (depends on 49) The method according to claim 49, further comprising: in a contention-based random access procedure, sending to said network node device a third message including an identifier specific to said communication device according to said TDD configuration in said system information block. ### Claim 51 (depends on 50) The method according to claim 50, further comprising: switching said communication device into a dynamic TDD capable mode to support multiple dynamic TDD configurations; receiving from said network node device a fourth message including a contention resolution by monitoring downlink channels according to said multiple dynamic TDD configurations. ### Claim 52 (depends on 50) The method according to claim 50, further comprising: receiving from said network node device a fourth message including a contention resolution according to said TDD configuration in said system information block; switching said communication device into a dynamic TDD capable mode to support multiple dynamic TDD configurations. ### Claim 53 (depends on 51) The method according to claim 51, wherein each of the multiple dynamic TDD configurations has uplink subframes that belong to a subset of uplink subframes of said TDD configuration in said system information block and downlink subframes that belong to a subset of downlink subframes of said at least another TDD configuration informed via dedicated Radio Resource Control signaling. ### Claim 54 (depends on 52) The method according to claim 52, wherein each of the multiple dynamic TDD configurations has uplink subframes that belong to a subset of uplink subframes of said TDD configuration in said system information block and downlink subframes that belong to a subset of downlink subframes of said at least another TDD configuration informed via dedicated Radio Resource Control signaling. ### Claim 55 (depends on 49) The method according to claim 49, wherein said communication device is handed over from a source cell served by a source network node device to a target cell served by said network node device, and wherein said TDD configuration in said system information block is informed from said network node device to said source network node device and signaled to said communication device from said source network node device. ### Claim 56 (depends on 49) The method according to claim 49, wherein said communication device is a user equipment which is in an out-of-sync or link-failure status. ### Claim 57 A method for operating a network node device, comprising: receiving from a communication device a first message including a random access preamble according to a TDD configuration in a system information block; sending to said communication device a second message including a random access response using said random access preamble according to said TDD configuration in said system information block, wherein said communication device is assigned more than one TDD configurations before a random access procedure and wherein said more than one TDD configurations include said TDD configuration in said system information block and further include at least another TDD configuration informed via dedicated Radio Resource Control signaling. ### Claim 58 (depends on 57) The method according to claim 57, further comprising: in a contention-based random access procedure, receiving from said communication device a third message including an identifier specific to said communication device according to said TDD configuration in said system information block. ### Claim 59 A communication device, comprising: a sending unit configured to send to a network node device a first message including a random access preamble according to a Time Division Duplex, TDD, configuration in a system information block; a receiving unit configured to receive from said network node device a second message including a random access response using said random access preamble according to said TDD configuration in said system information block, wherein said communication device has more than one TDD configurations before initiating a random access procedure and said more than one TDD configurations include said TDD configuration in said system information block and further include at least another TDD configuration informed via dedicated Radio Resource Control signaling. ### Claim 60 (depends on 59) The communication device according to claim 59, wherein said sending unit is further configured to, in a contention-based random access procedure, send to said network node device a third message including an identifier specific to said communication device according to said TDD configuration in said system information block. ### Claim 61 (depends on 59) The method according to claim 59, wherein each of the multiple dynamic TDD configurations has uplink subframes that belong to a subset of uplink subframes of said TDD configuration in said system information block and downlink subframes that belong to a subset of downlink subframes of said at least another TDD configuration informed via dedicated Radio Resource Control signaling. ### Claim 62 (depends on 59) The communication device according to claim 59, further comprising: a controlling unit configured to switch said communication device into a dynamic TDD capable mode to support multiple dynamic TDD configurations; wherein said receiving unit is further configured to receive from the network node device a fourth message including a contention resolution by monitoring downlink channels according to said multiple dynamic TDD configurations. ### Claim 63 (depends on 59) The communication device according to claim 59, wherein said receiving unit is further configured to receive from the network node device a fourth message including a contention resolution according to said TDD configuration in said system information block; said communication device further comprises a controlling unit configured to switch said communication device into a dynamic TDD capable mode to support multiple dynamic TDD configurations ### Claim 64 (depends on 59) The communication device according to claim 59, wherein said communication device is handed over from a source cell served by a source network node device to a target cell served by said network node device, and wherein said TDD configuration in said system information block is informed from said network node device to said source network node device and signaled to said communication device from said source network node device. ### Claim 65 (depends on 59) The communication device according to claim 59, wherein said communication device is a user equipment which is in an out-of-sync or link-failure status.