# US 12,004,037 B2 · Method and system for providing a fallback solution in a multi-tenant communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,037 B2 - Document ID: US12004037B2 - Status: Granted - Kind: B2 - Application number: 17/367,823 - Filed: 2021-07-06 - Published: 2022-01-27 - Granted: 2024-06-04 - Earliest claimed: 2019-10-30 - Assignees: Motorola Solutions, Inc. - Applicants: Motorola Solutions, Inc. - Inventors: Daniel J McDonald; Svend Frandsen - Web page: https://patentgrep.com/patent/US12004037B2 ## CPC - H04W 4/08: User group management - H04W 36/305: {Handover due to radio link failure (control signalling for hand-off failure H04W36/0079)} - H04L 69/40: for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) - H04W 4/10: Push-to-Talk [PTT] or Push-On-Call services - H04W 4/16: Communication-related supplementary services, e.g. call-transfer or call-hold - H04W 24/04: Arrangements for maintaining operational condition - H04W 36/142: {over the same radio air interface technology} - H04W 76/12: Setup of transport tunnels - H04W 76/18: Management of setup rejection or failure - H04W 76/19: Connection re-establishment - H04W 92/04: Interfaces between hierarchically different network devices - 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 A method and system for providing a fallback solution in a multi-tenant communication system is provided. A cloud-based call processing service receives a voice call initiation request from a first mobile device located at a first communication system. The voice call initiation request includes a request to complete a voice call with a second mobile device located at a second communication system. Resources are allocated at the first communication system and the second communication system. The cloud-based call processing service establishes a call between the first mobile device and the second mobile device. At some point the first communication system determines that it should fallback to single site operation. In fallback mode, call processing functionality is performed at the first communication system for the first mobile device. ## Claims ### Claim 1 A method for providing a fallback solution in a multi-tenant communication system, the method comprising: communicating between a first RF site at a first radio-access network (RAN) and a second RF site at a second RAN through a first link established through a cloud-based call-processing service; determining that a second link through the cloud-based call-processing service has failed, wherein the second link established communication between a third RF site on the first RAN and a fourth RF site on the second RAN; implementing a fallback mode of communication for the first RAN, in response to the second link going down, wherein the fallback mode of communication allows communication between RF sites existing only at the first communication system; in response to the implementation of the fallback mode of communication, dropping the first link through the cloud-based call-processing service. ### Claim 2 (depends on 1) The method of claim 1 further comprising the step of: replicating a first portion of a first database at the cloud-based call-processing service at a second database existing at the first RAN, wherein the first portion of the first database replicated at the second database comprises radio and talkgroup configuration and call activity information for only the first RAN, and is utilized to provide local communication within the first RAN when communication with the cloud-based call-processing service fails. ### Claim 3 A radio-access network (RAN) having a first RF site in communication with a second RF site at a second RAN through a first link established through a cloud-based call-processing service, the radio-access network comprising: a fallback core configured to: determine that a second link through the cloud-based call-processing service has failed, wherein the second link established communication between a third RF site on the first RAN and a fourth RF site on the second RAN; implement a fallback mode of communication for the first RAN, in response to the second link going down, wherein the fallback mode of communication allows communication between RF sites existing only at the first communication system; and in response to the implementation of the fallback mode of communication, drop the first link through the cloud-based call-processing service. ### Claim 4 (depends on 3) The radio-access network of claim 3 further comprising: a database comprising a replicated a first portion of a first database at a cloud-based call-processing service, wherein the database comprises radio and talkgroup configuration and call activity information for only the radio-access network and is utilized to provide local communication within the radio-access network when communication with the cloud-based call-processing service fails. ### Claim 5 (depends on 3) The RAN of claim 3 wherein the fallback core is further configured to: determine that a predetermined number of links from the first RAN to the cloud-based call-processing service have failed; when a predetermined number of links have failed then the fallback mode of communication: drop all communication between the all RF sites within the first RAN and the cloud-based call-processing service; establish communication between all RF site within the first RAN and a local call-processing service; allow communication between all RF sites within the first RAN through the local call-processing service.