# US 10,485,035 B2 · Adaptive peer status check over wireless local area networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,485,035 B2 - Document ID: US10485035B2 - Status: Granted - Kind: B2 - Application number: 15/560,427 - Filed: 2015-04-28 - Published: 2018-03-29 - Granted: 2019-11-19 - Earliest claimed: 2015-04-28 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget Lm Ericsson (Publ) - Inventors: Jichun Dong; Jinyan Liu; Wei Xu - Web page: https://patentgrep.com/patent/US10485035B2 ## CPC - H04W 76/12: Setup of transport tunnels - H04W 76/22: Manipulation of transport tunnels - H04W 76/25: Maintenance of established connections - H04W 76/38: triggered by timers - H04W 84/12: WLAN [Wireless Local Area Networks] - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Embodiments of the invention relate to methods and apparatus for adapting the IKE/IPsec peer status time interval in accordance with the service delivered to the UE. The peer status time interval is used to detect IKE/IPsec peer liveliness in the UE. The evolved Packet Data Gateway, ePDG, sets the peer status time interval according to the type of bearers or GTP tunnels established with the PDN GW. The ePDG uses a default peer status interval T1 when the ePDG connects the UE to the PDN using the default GTP tunnel established at the time of PDN connection establishment. When a multimedia service is established for the UE, one or more dedicated GTP tunnels of different quality of service requirements may be established at the ePDG. The ePDG would then use a different peer status time interval T2 that may be derived from the quality of service parameters associated with the one or more dedicated GTP tunnels. ## Claims ### Claim 1 A method in an evolved Packet data gateway, ePDG, for determining peer status check interval for a peer User Equipment, UE, the method comprising: establishing a packet data network, PDN, connection comprising a concatenation of an Internet Protocol Security, IPsec, tunnel established with the peer UE, and a corresponding default General Packet Radio Service, GPRS tunneling Protocol, GTP, tunnel established with a packet data gateway; using a first peer status time interval in accordance with the default GTP tunnel to detect liveliness of the peer UE over the IPSec, tunnel; and upon establishment of a dedicated GTP tunnel with the packet data gateway for the PDN connection, using a second peer status time interval in accordance with the dedicated GTP tunnel to detect liveliness of the peer UE over the IPSec tunnel until deactivation of the dedicated GTP tunnel, the second peer status time interval being different from the first peer status time interval. ### Claim 2 (depends on 1) The method of claim 1, wherein the first peer status time interval and the second peer status time interval are pre-configured. ### Claim 3 (depends on 1) The method of claim 1, wherein the second peer status time interval is less than the first peer status time interval. ### Claim 4 (depends on 1) The method of claim 1, wherein using the first peer status time interval to detect liveliness of the peer UE further comprises sending at every first peer status time interval a peer status message to the peer UE to verify peer UE liveliness. ### Claim 5 (depends on 4) The method of claim 4, wherein if the ePDG fails to receive an acknowledgement to the peer status message from the peer UE, sending a second peer status message after the first peer status time interval expires. ### Claim 6 (depends on 5) The method of claim 5, wherein if the ePDG fails to receive an acknowledgement to the second peer status message, sending a third peer status message to the peer UE after a first fraction of the first peer status interval timer expires. ### Claim 7 (depends on 6) The method of claim 6, wherein if the ePDG fails to receive an acknowledgement to the third peer status message, sending a fourth peer status message to the peer UE after a second fraction of the first peer status interval timer expires wherein the second fraction is smaller than the first fraction. ### Claim 8 (depends on 4) The method of claim 4, wherein the method further comprises determining the peer UE is unresponsive after sending at least three subsequent peer status messages to the UE. ### Claim 9 (depends on 1) The method of claim 1, wherein using the second peer status time interval to detect liveliness of the peer UE further comprises sending at every second peer status time interval a peer status message to the peer UE to verify peer UE liveliness. ### Claim 10 (depends on 9) The method of claim 9, wherein the method further comprises determining the peer UE is unresponsive after sending at least three subsequent peer status messages to the peer UE. ### Claim 11 (depends on 1) The method of claim 1 further comprising: upon releasing the dedicated GTP tunnel while maintaining the default GTP tunnel established for the PDN connection, reverting to using the first peer status time interval to detect liveliness of the peer UE over the IPSec tunnel. ### Claim 12 (depends on 1) The method of claim 1, wherein the method further comprises determining at least one of the first peer status time interval and the second peer status time interval using quality of service, QoS, parameters associated with corresponding established GTP tunnels. ### Claim 13 (depends on 12) The method of claim 12, wherein the QoS parameters comprise at least one of QoS class identifier, QCI, and guaranteed bit rate, GBR. ### Claim 14 An evolved packet data gateway ePDG, configured to determine peer status check interval for a peer User Equipment, UE, the ePDG comprising a circuitry configured to: establish a packet data network, PDN, connection comprising a concatenation of an Internet Protocol Security, IPsec, tunnel established with the peer UE and a corresponding default General Packet Radio Service, GPRS tunneling Protocol, GTP, tunnel established with a packet data gateway; using a first peer status time interval in accordance with the default GTP tunnel to detect liveliness of the peer UE over the IPSec, tunnel; and upon establishment of a dedicated GTP tunnel with the packet data gateway for the PDN connection, using a second peer status time interval in accordance with the dedicated GTP tunnel to detect liveliness of the peer UE over the IPSec tunnel until deactivation of the dedicated GTP tunnel, the second peer status time interval being different from the first peer status time interval. ### Claim 15 (depends on 14) The ePDG of claim 14, wherein the circuitry comprises a processor, a communication interface and a memory, the memory containing instructions executable by the processor. ### Claim 16 (depends on 14) The ePDG of claim 14, wherein the second peer status time interval is less than the first peer status time interval. ### Claim 17 (depends on 14) The ePDG of claim 14, wherein the circuitry is further configured to upon release of the dedicated GTP tunnel, while maintaining the default GTP tunnel established for the PDN connection, revert to using the first peer status time interval to detect liveliness of the peer UE over the IPsec tunnel. ### Claim 18 (depends on 14) The ePDG of claim 14, wherein the circuitry is further configured to determine at least one of the first peer status time interval and the second peer status time interval using quality of service, QoS, parameters associated with corresponding established GTP tunnels. ### Claim 19 (depends on 18) The ePDG of claim 18, wherein the QoS parameters comprise at least one of QoS class identifier, QCI, and guaranteed bit rate, GBR.