# US 2018/0295522 A1 · Warning of spectrum access revocation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0295522 A1 - Document ID: US20180295522A1 - Status: Published application - Kind: A1 - Application number: 15/479,449 - Filed: 2017-04-05 - Published: 2018-10-11 - Earliest claimed: 2017-04-05 - Assignees: Nokia Solutions and Networks Oy - Applicants: Nokia Solutions and Networks Oy - Inventors: Curt WONG; Ruth GAYDE; Tarun AGARWAL; Alex HIRSBRUNNER - Web page: https://patentgrep.com/patent/US20180295522A1 ## CPC - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W 76/30: Connection release - H04L 67/143: Termination or inactivation of sessions, e.g. event-controlled end of session - H04W 4/90: Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS] - H04W 76/50: for emergency connections - 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 Various communication systems may benefit from improved signaling. For example, certain communication systems may benefit from improved signaling before network access is revoked through a citizens broadband radio service. A method may include receiving at a network entity from a citizens broadband radio service device a warning message. The warning message may include a drop time after which communication between a network and a user equipment using the citizens broadband radio service will terminate. The method may also include triggering the performing of an action based on the warning message by the network before the drop time. ## Claims ### Claim 1 A method, comprising: receiving at a network entity from a citizens broadband radio service device a warning message, wherein the warning message includes a drop time after which communication between a network and a user equipment via the citizens broadband radio service will terminate; and triggering performance of an action based on the warning message by the network before the drop time. ### Claim 2 (depends on 1) The method according to claim 1, wherein the warning message comprises a radio frequency unavailable indication. ### Claim 3 (depends on 1) The method according to claim 1, further comprising: establishing an emergency session with the user equipment via the citizens broadband radio service, wherein the emergency session is ongoing before the drop time. ### Claim 4 (depends on 3) The method according to claim 3, wherein the emergency session connects the user equipment to a public safety answering point. ### Claim 5 (depends on 1) The method according to claim 1, wherein the network entity is a policy and charging rules function, a proxy call session control function, or a mobility management entity. ### Claim 6 (depends on 1) The method according to claim 1, wherein the warning message is received at a proxy call session control function from the citizens broadband radio service device through a policy and charging rules function. ### Claim 7 (depends on 1) The method according to claim 1, wherein the warning message comprises a reason for terminating communication between the network and the user equipment via the citizens broadband radio service. ### Claim 8 (depends on 1) The method according to claim 1, wherein the warning message is included in a user equipment context release request procedure or a radio bearer modification procedure. ### Claim 9 (depends on 1) The method according to claim 1, wherein the action is performed using internet protocol multimedia subsystem signaling. ### Claim 10 (depends on 1) The method according to claim 1, wherein the action comprises at least one of seeking a last location of the user equipment, including a reason for the termination in a charging data record, playing an announcement to an end user or the user equipment, recording a caller message from the end user, or forwarding a message to an emergency responder. ### Claim 11 A method, comprising: receiving at a citizens broadband radio service device a warning message, wherein the warning message includes a drop time after which communication between a user equipment and a network via the citizens broadband radio service will terminate; and transmitting the warning message from the citizens broadband radio service device to a network entity, wherein the warning message triggers performance of an action by the network before the drop time based on the warning message. ### Claim 12 (depends on 11) The method according to claim 11, wherein the warning message comprises a radio frequency unavailable indication. ### Claim 13 (depends on 11) The method according to claim 11, further comprising: receiving the warning message comprising the drop time from a spectrum access system. ### Claim 14 (depends on 13) The method according to claim 13, wherein the drop time is determined by the spectrum access system. ### Claim 15 (depends on 13) The method according to claim 13, wherein the warning message is triggered by the spectrum access system to terminate access of the user equipment to the network via the citizens broadband radio service in favor of higher priority usages. ### Claim 16 (depends on 11) The method according to claim 11, wherein the warning message comprises a reason for terminating communication between the network and the user equipment via the citizens broadband radio service. ### Claim 17 (depends on 11) The method according to claim 11, further comprising: establishing an emergency session between the network entity and the user equipment via the citizens broadband radio service, wherein the emergency service is ongoing before the drop time. ### Claim 18 (depends on 17) The method according to claim 17, wherein the action is performed using internet protocol multimedia subsystem signaling. ### Claim 19 (depends on 11) The method according to claim 11, wherein the network entity is a policy and charging rules function, a proxy call session control function, or a mobility management entity. ### Claim 20 (depends on 11) The method according to claim 11, wherein the warning message is transmitted from the citizens broadband radio service device to a proxy call session control function through a policy and charging rules function. ### Claim 21 (depends on 11) The method according to claim 11, wherein the action comprises at least one of seeking a last location of the user equipment, including a reason for the termination in a charging data record, playing an announcement to an end user or the user equipment, recording a caller message from the end user, or forwarding a message to an emergency responder. ### Claim 22 An apparatus, comprising: at least one memory comprising computer program code; at least one processor; wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to: receive at a citizens broadband radio service device a warning message, wherein the warning message includes a drop time after which communication between a user equipment and a network via the citizens broadband radio service will terminate; and transmit the warning message from the citizens broadband radio service device to a network entity, wherein the warning message triggers performance of an action by the network before the drop time based on the warning message.