# US 2021/0243705 A1 · Methods for Adapting Over-the-Air Synchronization to Radio Conditions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243705 A1 - Document ID: US20210243705A1 - Status: Published application - Kind: A1 - Application number: 17/151,368 - Filed: 2021-01-18 - Published: 2021-08-05 - Earliest claimed: 2014-07-29 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Angelo Centonza; Havish Koorapaty - Web page: https://patentgrep.com/patent/US20210243705A1 ## CPC - H04W 56/001: {Synchronization between nodes} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0073: {Allocation arrangements that take into account other cell interferences} - H04W 56/0015: {one node acting as a reference for the others} - 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 Methods for enabling and disabling of muting patterns in Radio Access Network, RAN, nodes for the purpose of allowing better detection and use of reference symbols used for synchronization. An example method for facilitating over-the-air synchronization with a neighboring base station is implemented in a base station operating in a wireless communications network. The method comprises determining that a first neighbor cell of a plurality of neighbor cells is interfering with or is likely to interfere with a signal, from the second neighbor cell, that is used for synchronization. The method further comprises sending, towards the first neighbor cell and in response to said determining, a request for activation of a reference signal muting pattern by the first neighbor cell. ## Claims ### Claim 1 A method, in a base station operating in a wireless communications network, for facilitating over-the-air synchronization with a neighboring base station, the method comprising: identifying a first neighbor cell as a desired over-the-air synchronization source, based on at least one of a stratum level or synchronization status of the first neighbor cell; determining that a signal being transmitted by a second neighbor cell is interfering with or is likely to interfere with a reference signal transmitted by the first neighbor cell and needed by the base station for synchronization; and sending towards the second neighbor cell, in response to said determining, a request for activation of a reference signal muting pattern by the second neighbor cell. ### Claim 2 (depends on 1) The method of claim 1, further comprising subsequently determining that the reference signal from the first neighbor cell is not needed or is unavailable for synchronization and, in response, sending a message, towards the second neighbor cell, indicating that the reference signal muting pattern may be deactivated. ### Claim 3 (depends on 1) The method of claim 1, wherein the request for activation is sent to a controlling node in the wireless communications network, wherein the controlling node controls a base station corresponding to the second cell. ### Claim 4 (depends on 1) The method of claim 1, further comprising receiving synchronization information from at least the first neighbor cell, the synchronization information indicating at least one of the stratum level and synchronization status, wherein said identifying is based on the received synchronization information. ### Claim 5 (depends on 1) The method of claim 1, further comprising receiving an indication of whether a reference signal muting pattern is available for the second neighbor cell, wherein said sending of the request is responsive to receiving said indication. ### Claim 6 (depends on 5) The method of claim 5, wherein the indication comprises or is associated with an identification of one or more muting patterns available for the second neighbor cell. ### Claim 7 (depends on 1) The method of claim 1, wherein the request for activation of the reference signal muting pattern includes an identification of one or more resources that should be muted, the identification of one or more resources that should be muted identifying a subframe pattern, or a pattern periodicity, or both. ### Claim 8 (depends on 1) The method of claim 1, further comprising receiving, in response to said request, information identifying which resources are being muted or are to be muted by the second neighbor cell. ### Claim 9 A base station apparatus comprising: a communications interface circuit configured to communicate with one or more other base stations or with one or more control nodes, or one or more of each; and a processing circuit configured to control the communications interface circuit and further configured to identify a first neighbor cell as a desired over-the-air synchronization source, based on at least one of a stratum level or synchronization status of the first neighbor cell; determine that a signal being transmitted by a second neighbor cell is interfering with or is likely to interfere with a reference signal transmitted by the first neighbor cell and needed by the base station for synchronization; and send towards the second neighbor cell, in response to said determining, a request for activation of a reference signal muting pattern by the second neighbor cell. ### Claim 10 (depends on 9) The base station apparatus of claim 9, wherein the processing circuit is further configured to subsequently determine that the signal from the first neighbor cell is not needed or is unavailable for synchronization and, in response, send a message towards the second neighbor cell, via the communications interface circuit, the message indicating that the reference signal muting pattern may be deactivated. ### Claim 11 (depends on 9) The base station apparatus of claim 9, wherein the processing circuit is further configured to receive synchronization information from at least the first neighbor cell, the synchronization information indicating at least one of the stratum level and synchronization status, and to identify the first neighbor cell as a desired over-the-air synchronization source based on the received synchronization information. ### Claim 12 (depends on 9) The base station apparatus of claim 9, wherein the processing circuit is further configured to receive, via the communications interface circuit, an indication of whether a reference signal muting pattern is available for the second neighbor cell, wherein said sending of the request is responsive to receiving said indication. ### Claim 13 (depends on 12) The base station apparatus of claim 12, wherein the indication comprises or is associated with an identification of one or more muting patterns available for the second neighbor cell. ### Claim 14 (depends on 9) The base station apparatus of claim 9, wherein the request for activation of the reference signal muting pattern includes a list of cells for which a muting pattern should be applied. ### Claim 15 (depends on 9) The base station apparatus of claim 9, wherein the request for activation of the reference signal muting pattern includes an identification of one or more resources that should be muted. ### Claim 16 (depends on 15) The base station apparatus of claim 15, wherein the identification of one or more resources that should be muted comprises a subframe pattern, or a pattern periodicity, or both. ### Claim 17 (depends on 9) The base station apparatus of claim 9, wherein the processing circuit is further configured to perform synchronization based on the signal from the first neighbor cell. ### Claim 18 (depends on 9) The base station apparatus of claim 9, wherein the processing circuit is further configured to receive, via the communications interface circuit, information identifying which resources are being muted or are to be muted by the second neighbor cell.