# US 2023/0056778 A1 · Method and apparatus 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 2023/0056778 A1 - Document ID: US20230056778A1 - Status: Published application - Kind: A1 - Application number: 17/792,763 - Filed: 2021-01-13 - Published: 2023-02-23 - Earliest claimed: 2020-01-17 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Zhipeng LIN - Web page: https://patentgrep.com/patent/US20230056778A1 ## CPC - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04B 7/18508: {with satellite system used as relay, i.e. aeronautical mobile satellite service} - H04B 7/18521: {Systems of inter linked satellites, i.e. inter satellite service (for optical links between satellites H04B10/118)} - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04W 74/0836: with 2-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) - H04B: TRANSMISSION ## Abstract Various embodiments of the present disclosure provide a method for random access. The method which may be performed by a terminal device includes determining a random access occasion based at least in part on random access configuration information for a non-terrestrial network. The method further includes transmitting a preamble to a network node in the non-terrestrial network, according to the determined random access occasion. ## Claims ### Claim 1 A method performed by a terminal device, comprising: determining a random access occasion based at least in part on random access configuration information for a non-terrestrial network; and transmitting a preamble to a network node in the non-terrestrial network, according to the determined random access occasion. ### Claim 2 (depends on 1) The method according to claim 1, wherein the random access configuration information indicates configuration of two consecutive random access occasions so that a time interval between the two consecutive random access occasions is equal to or larger than an interval threshold. ### Claim 3 (depends on 2) The method according to claim 2, wherein the interval threshold is determined based at least in part on a maximum one way delay and a minimum one way delay of signal transmission in the non-terrestrial network. ### Claim 4 (depends on 1) The method according to claim 1, wherein the random access configuration information indicates configuration of two consecutive random access occasions so that two preamble receiving windows associated with the two consecutive random access occasions are not overlapped. ### Claim 5 (depends on 1) The method according to claim 1, wherein the random access configuration information indicates a first set of random access occasions configured for the non-terrestrial network in a predetermined time duration, and wherein the first set of random access occasions is a subset of a second set of random access occasions configured for a terrestrial network in the predetermined time duration. ### Claim 6 (depends on 5) The method according to claim 5, wherein the random access configuration information comprises a first bit map mask to indicate one or more subframes within one or more system frames, and wherein the first set of random access occasions for the non-terrestrial network are configured on the one or more subframes. ### Claim 7 (depends on 1) The method according to claim 1, wherein the random access configuration information comprises a second bit map mask to invalidate one or more of a second set of random access occasions configured for a terrestrial network in a predetermined time duration, so that only a subset of the second set of random access occasions in the predetermined time duration are valid for the non-terrestrial network. ### Claim 8 (depends on 1) The method according to claim 1, wherein the random access configuration information indicates a random access configuration period, and a length of the random access configuration period meets a specific criterion for the non-terrestrial network. ### Claim 9 (depends on 8) The method according to claim 8, wherein the random access configuration information comprises an offset to a random access configuration period for a terrestrial network to indicate the random access configuration period for the non-terrestrial network. ### Claim 10 (depends on 1) The method according to claim 1, wherein the random access configuration information is received from the network node by the terminal device. ### Claim 11 (depends on 1) The method according to claim 1, wherein the random access configuration information is predetermined for the non-terrestrial network separately from a terrestrial network. ### Claim 12 (depends on 1) The method according to claim 1, wherein the random access configuration information comprises at least one of: a random access configuration period for the non-terrestrial network in number of system frames; and an indicator of a subframe on which a random access occasion for the non-terrestrial network is configured. ### Claim 13 (depends on 1) The method according to claim 1, wherein the random access configuration information is applicable to at least one of a four-step random access procedure and a two-step random access procedure. ### Claim 14 A method performed by a network node, comprising: determining a preamble receiving window based at least in part on random access configuration information for a non-terrestrial network; and receiving, within the preamble receiving window, a preamble transmitted from a terminal device in the non-terrestrial network. ### Claim 15 (depends on 14) The method according to claim 14, wherein the random access configuration information indicates configuration of two consecutive random access occasions so that a time interval between the two consecutive random access occasions is equal to or larger than an interval threshold. ### Claim 16 (depends on 15) The method according to claim 15, wherein the interval threshold is determined based at least in part on a maximum one way delay and a minimum one way delay of signal transmission in the non-terrestrial network. ### Claim 17 (depends on 14) The method according to claim 14, wherein the random access configuration information indicates configuration of two consecutive random access occasions so that two preamble receiving windows associated with the two consecutive random access occasions are not overlapped. ### Claim 18 (depends on 14) The method according to claim 14, wherein the random access configuration information indicates a first set of random access occasions configured for the non-terrestrial network in a predetermined time duration, and wherein the first set of random access occasions is a subset of a second set of random access occasions configured for a terrestrial network in the predetermined time duration. ### Claim 19 (depends on 18) The method according to claim 18, wherein the random access configuration information comprises a first bit map mask to indicate one or more subframes within one or more system frames, and wherein the first set of random access occasions for the non-terrestrial network are configured on the one or more subframes. ### Claim at position 20 20-26. (canceled) ### Claim 27 A terminal device, comprising: one or more processors; and one or more memories comprising computer program codes, the one or more memories and the computer program codes configured to, with the one or more processors, cause the terminal device at least to: determine a random access occasion based at least in part on random access configuration information for a non-terrestrial network; and transmit a preamble to a network node in the non-terrestrial network, according to the determined random access occasion. ### Claim at position 22 28-66. (canceled)