# US 2021/0242970 A1 · Terminal device, network node and method for random access in coverage enhancement operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242970 A1 - Document ID: US20210242970A1 - Status: Published application - Kind: A1 - Application number: 17/232,962 - Filed: 2021-04-16 - Published: 2021-08-05 - Earliest claimed: 2018-08-02 - Assignees: Sony Group Corporation - Applicants: Sony Group Corporation - Inventors: Svante ALNÅS; Lars NORD; Anders BERGGREN; Linh TRANG - Web page: https://patentgrep.com/patent/US20210242970A1 ## CPC - H04L 1/08: by repeating transmission, e.g. Verdan system {(H04L1/1858 and H04L1/189 take precedence)} - H04W 16/26: Cell enhancers {or enhancement}, e.g. for tunnels, building shadow - H04W 74/004: {in the uplink, i.e. towards network} - H04W 74/0858: {collision detection} - H04W 48/12: using downlink control channel - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A terminal device is operative to receive a broadcast message (91) from a cellular network, the broadcast message (91) including at least one bit associated with coverage enhancement, CE, operation of the terminal device. The terminal device is operative to control, when the terminal device is in CE operation, a radio interface to selectively delay, based on the at least one bit included in the broadcast message (91), a CE level dependent repetition of a random access preamble transmission (93, 94). ## Claims ### Claim 1 A terminal device, comprising: a radio interface (21) operative to receive a broadcast message (91) from a cellular network (30, 40), the broadcast message (91) including at least one bit associated with coverage enhancement, CE, operation of the terminal device (11, 12; 20); and an electronic circuit (24) operative to control, when the terminal device (11, 12; 20) is in CE operation, the radio interface (21) to selectively delay, based on the at least one bit included in the broadcast message (91), a CE level dependent repetition of a random access preamble transmission (93, 94). ### Claim 2 (depends on 1) The terminal device of claim 1, wherein the electronic circuit (24) is operative to delay the CE level dependent repetition of the random access preamble transmission (93, 94) based on at least one Of: a subscription level of the terminal device (11, 12; 20), information on whether radio access is required for non time critical data, and/or a device type of the terminal device (11, 12; 20). ### Claim 3 (depends on 2) The terminal device of claim 2, wherein the electronic circuit (24) is operative to control a backoff behavior that delays the CE level dependent repetition of the random access preamble transmission (93, 94) based on the at least one bit included in the broadcast message (91); and the subscription level and/or the device type of the terminal device (11, 12; 20). ### Claim 4 (depends on 2, 3) The terminal device of claim 2 or claim 3, wherein the electronic circuit (24) is operative to delay the CE level dependent repetition of the random access preamble transmission (93, 94) until a trigger event is detected. ### Claim 5 (depends on 4) The terminal device of claim 4, wherein the trigger event is dependent on the subscription level and/or the device type. ### Claim 6 (depends on 2, 3, 4, 5) The terminal device of any one of claims 2 to 5, wherein the electronic circuit (24) is operative to detect time-dependent changes in CE level (81, 87), wherein the electronic circuit (24) is operative to cause the radio interface (21) to perform the CE level dependent repetition of the random access preamble transmission (93, 94) based on the detected time-dependent changes in CE level (81, 87). ### Claim 7 (depends on 6) The terminal device of claim 6, wherein the electronic circuit (24) is operative to cause the radio interface (21) to perform the CE level dependent repetition of the random access preamble transmission (93, 94) based on a comparison of the detected time-dependent changes in CE level (81, 87) to a CE level threshold (82). ### Claim 8 (depends on 2, 3, 4, 5, 6, 7) The terminal device of any one of claims 2 to 7, wherein the electronic circuit (24) is operative to control the radio interface (21) to perform the CE level dependent repetition of the random access preamble transmission (93, 94) in response to occurrence of the earlier of: the CE level (81, 87) reaching the CE level threshold (82), expiry of a backoff timer. ### Claim 9 (depends on 8) The terminal device of claim 8, wherein at least one of a timer value (86, 88) of the backoff timer and the CE level threshold (82) is dependent on the subscription level. ### Claim 10 (depends on 9) The terminal device of claim 9, wherein the timer value (86, 88) of the backoff timer is further dependent on the CE level. ### Claim 11 (depends on 2, 3, 4, 5, 6, 7, 8, 9, 10) The terminal device of any one of claims 2 to 10, wherein the electronic circuit (24) is operative to determine whether the subscription level of the terminal device (11, 12; 20) is included in a sub-set of subscription levels and to delay the CE level dependent repetition of the random access preamble transmission (93, 94) selectively only if the subscription level of the terminal device (11, 12; 20) is included in the sub-set. ### Claim 12 The terminal device of any one of the preceding claims, wherein the at least one bit associated with CE operation is included in a system information block. ### Claim 13 The terminal device of any one of the preceding claims, wherein the electronic circuit (24) is operative to delay the CE level dependent repetition of the random access preamble transmission (93, 94) based on a subscription information of the terminal device (11, 12; 20). ### Claim 14 A cellular network node, comprising: a radio interface (31) to receive random access preambles (92-94) from terminal devices (11-13; 20), and a circuit (32) coupled to the radio interface (31) and operative to perform congestion monitoring for PRACH resources for one or several coverage enhancement, CE, levels, and control the radio interface (31) based on the congestion monitoring to broadcast a message (91) that includes at least one bit associated with CE operation of terminal devices (11, 12; 20) to cause part of the terminal devices (11, 12; 20) to delay a CE level dependent repetition of a random access preamble transmission (93, 94). ### Claim 15 (depends on 14) The cellular network node of claim 14, wherein the cellular network node (30) is operative to set the at least one bit associated with CE operation of terminal devices (11, 12; 20) so as to prioritize terminal devices (11, 12; 20) for performing random access in CE operation. ### Claim 16 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15) A communication system, comprising: a cellular network comprising the cellular network node (30) of claim 14 or claim 15, a first terminal device (11) of any one of claims 1 to 13, the first terminal device (11) having a first subscription level, a second terminal device (12) of any one of claims 1 to 13, the second terminal device (12) having a second subscription level different from the first subscription level, wherein, in response to receiving the broadcast message (91) that includes the at least one bit associated with CE operation, the first terminal device (11) and the second terminal device (12) activate different backoff procedures to selectively delay a CE level dependent repetition of a random access preamble transmission (93, 94) in dependence of the subscription level of the respective terminal device (11, 12). ### Claim 17 (depends on 16) The communication system of claim 16, wherein the cellular network is operative to provision the first terminal device (11) and/or the second terminal device (12) with at least one parameter for a CE level dependent backoff behavior. ### Claim 18 (depends on 16, 17) The communication system of claim 16 or claim 17, wherein the at least one parameter for the CE level dependent backoff behavior comprises at least one of: a set of back-off rules, a subscription level, back-off factors, and/or CE level dependent thresholds. ### Claim 19 A method of performing random access when a terminal device (11, 12; 20) is in coverage enhancement operation, the method comprising: receiving, by the terminal device (11, 12; 20), a broadcast message (91) from a cellular network (30, 40), the broadcast message (91) including at least one bit associated with coverage enhancement, CE, operation of the terminal device; and controlling, when the terminal device (11, 12; 20) is in CE operation, a radio interface (21) of the terminal device (11, 12; 20) to selectively delay, based on the at least one bit included in the broadcast message (91), a CE level dependent repetition of a random access preamble transmission (93, 94). ### Claim 20 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 19) The method of claim 19, which is performed by the terminal device (11, 12; 20) of any one of claims 1 to 13.