Systems and Methods for Interworking with over the Top Applications in Communications Network

Systems and methods are provided for facilitating communications with an operating system suspended OTT application on a user device. The methods include sending, from a P-CSCF or a WebRTC Gateway, to a push notification framework, a notification configured to cause the push notification framework to send a push notification to the suspended OTT application (IMS OTT application or WebRTC OTT application). The push notification may wake up the OTT application and cause a notification initiated REGISTRATION request to be sent by the OTT application. This can be initiated just before the IMS core network de-registers the OTT application based on a timer, or based on receipt of a SIP request (e.g. phone call received) when the OTT application is suspended. In addition, the push notification provides a lightweight authentication at the P-CSCF instead of a full blown authentication at the usual place S-CSCF.