# US 2021/0243802 A1 · Random access > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243802 A1 - Document ID: US20210243802A1 - Status: Published application - Kind: A1 - Application number: 17/250,021 - Filed: 2018-05-07 - Published: 2021-08-05 - Earliest claimed: 2018-05-07 - Assignees: Nokia Technologies Oy - Applicants: Nokia Technologies Oy - Inventors: Guillaume DECARREAU; Irina-Mihaela BALAN; Muhammad NASEER-UI-ISLAM - Web page: https://patentgrep.com/patent/US20210243802A1 ## CPC - H04W 74/002: {Transmission of channel access control information} - H04B 7/088: {using beam selection} - H04W 24/02: Arrangements for optimising operational condition - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 36/083: {wherein at least one of the access points is a moving node} - H04W 56/001: {Synchronization between nodes} - H04W 74/02: Hybrid access - H04W 74/0841: {with collision treatment} - H04W 76/19: Connection re-establishment - 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 An apparatus suitable for at least to: transmit at least one first random access request by using a first preamble to a first handover target cell or to a first beam provided by a serving cell, if responded, carry out a synchronization to the first handover target cell or to the first beam provided by the serving cell, if not responded, transmit at least one second random access request by using at least one second preamble to at least one second handover target cell or to at least one second beam provided by the serving cell; store information on not-responded random access requests and/or resources not used for random access requests, wherein the information comprises preambles used, and transmit, after being synchronized, the stored information to the first handover target cell, the at least one second handover target cell and/or the serving cell for being used in random access resource allocation. ## Claims ### Claim 1 An apparatus comprising: at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: transmit at least one first random access request by using a first preamble to a first handover target cell or to a first beam provided by a serving cell, if responded, carry out a synchronization to the first handover target cell or to the first beam provided by the serving cell, if not responded, transmit at least one second random access request by using at least one second preamble to at least one second handover target cell or to at least one second beam provided by the serving cell; store information on not-responded random access requests and/or resources not used for random access requests, wherein the information comprises preambles used, and transmit, after being synchronized, the stored information to the first handover target cell, the at least one second handover target cell and/or the serving cell for being used in random access resource allocation. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the information further comprises at least one of the following: number of the preambles, random access resources used, associated synchronization signal blocks, associated reference signals, transmission powers, transmission times (time slots used), random access radio network temporary identifier, number of efforts using a certain preamble, number of efforts using a certain resource, order of the non-responded random access requests, information whether the random access request was part of the contention-based random access or contention-free random access procedure and information on radio channel measurements. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the information further comprises information on responded random access requests. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the information is cell-specific and/or beam-specific. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the random access request cause is a handover or a beam failure recovery procedure. ### Claim 6 An apparatus comprising: at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive, by an access node, information on not-responded random access requests and/or resources not used for random access requests, wherein the information comprises random access preambles; analyze the information for finding out resources used for unsuccessful random access attempts or not used for random access attempts, the resources being indicated by the random access preambles, and avoid allocating the resources used for unsuccessful random access attempts and/or the resources not used for random access requests for further random access request transmissions. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the information further comprises at least one of the following: number of the preambles, random access resources used, associated synchronization signal blocks, associated reference signals, transmission powers, transmission times (time slots used), random access radio network temporary identifier, number of efforts using a certain preamble, number of efforts using a certain resource, order of the non-responded random access requests, information whether the random access request was part of the contention-based random access or contention-free random access procedure and information on radio channel measurements. ### Claim 8 (depends on 6) The apparatus of claim 6, wherein the information further comprises information on responded random access requests, and the at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to prefer the resources used for the responded random access requests in allocating resources for the further random access request transmissions. ### Claim 9 (depends on 6) The apparatus of claim 6, wherein the configuration further comprises a random access update release precondition for the least one handover candidate cell for the user device stop carrying out the measurements, if the random access update release precondition is fulfilled. ### Claim 10 (depends on 6) The apparatus of claims 6, further comprising causing the apparatus to, instead of or in addition to the avoiding allocating, preferring in the allocating successfully used random access resources. ### Claim 11 (depends on 6) The apparatus of claims 6, further comprising causing the apparatus to, instead of or in addition to the avoiding allocating, forwarding the information and/or result of the analyzing to another access node. ### Claim 12 A method comprising: transmitting at least one first random access request by using a first preamble to a first handover target cell or to a first beam provided by a serving cell, if responded, carrying out a synchronization to the first handover target cell or to the first beam provided by the serving cell, if not responded, transmitting at least one second random access request by using at least one second preamble to at least one second handover target cell or to at least one second beam provided by the serving cell; storing information on not-responded random access requests and/or resources not used for random access requests, wherein the information comprises preambles used, and transmitting, after being synchronized, the stored information to the first handover target cell, the at least one second handover target cell and/or the serving cell for being used in random access resource allocation. ### Claim 13 (depends on 12) The method of claim 12, wherein the information further comprises at least one of the following: number of the preambles, random access resources used, associated synchronization signal blocks, associated reference signals, transmission powers, transmission times (time slots used), random access radio network temporary identifier, number of efforts using a certain preamble, number of efforts using a certain resource, order of the non-responded random access requests, information whether the random access request was part of the contention-based random access or contention-free random access procedure and information on radio channel measurements. ### Claim 14 (depends on 12) The method of claim 12, wherein the information further comprises information on responded random access requests. ### Claim 15 (depends on 12) The method of claims 12, wherein the information is cell-specific and/or beam-specific. ### Claim 16 (depends on 12) The method of claims 12, wherein the random access request cause is a handover or a beam failure recovery procedure. ### Claim 17 A method comprising: receiving, by an access node, information on not-responded random access requests and/or resources not used for random access requests, wherein the information comprises random access preambles; analyzing the information for finding out resources used for unsuccessful random access attempts or not used for random access attempts, the resources being indicated by the random access preambles, and avoiding allocating the resources used for unsuccessful random access attempts and/or the resources not used for random access requests for further random access request transmissions. ### Claim 18 (depends on 17) The method of claim 17, wherein the information further comprises at least one of the following: number of the preambles, random access resources used, associated synchronization signal blocks, associated reference signals, transmission powers, transmission times (time slots used), random access radio network temporary identifier, number of efforts using a certain preamble, number of efforts using a certain resource, order of the non-responded random access requests, information whether the random access request was part of the contention-based random access or contention-free random access procedure and information on radio channel measurements. ### Claim 19 (depends on 17) The method of claim 17, wherein the information further comprises information on responded random access requests, further comprising preferring the resources used for the responded random access requests in allocating resources for the further random access request transmissions. ### Claim 20 (depends on 17) The method of claims 17, wherein the configuration further comprises a random access update release precondition for the least one handover candidate cell for the user device stop carrying out the measurements, if the random access update release precondition is fulfilled. ### Claim 21 (depends on 17) The method of claims 17, further comprising: instead of or in addition to the avoiding allocating, preferring in the allocating successfully used random access resources. ### Claim 22 (depends on 17) The method of claims 17, further comprising: instead of or in addition to the avoiding allocating, forwarding the information and/or result of the analyzing to another access node. ### Claim at position 23 23-25 (canceled) ### Claim 26 (depends on 6) The apparatus of claim 6, further comprising: causing the apparatus to, instead of or in addition to the avoiding allocating, prefer in the allocating successfully used random access resources and instead of or in addition to the avoiding allocating and/or the preferring in the allocating successfully used random access resources, forward the information and/or result of the analyzing to another access node. ### Claim 27 (depends on 17) The method of claim 17, further comprising: instead of or in addition to the avoiding allocating, preferring in the allocating successfully used random access resources and instead of or in addition to the avoiding allocating and/or the preferring in the allocating, forward the information and/or result of the analyzing to another access node.