Mission Critical Communications

A method comprising:

• transmitting, by a first wireless device to a second wireless device, a first session initiation protocol (SIP) REGISTER message comprising a first Contact header field, wherein the first Contact header field comprises an IMS identifier identifying a mission critical video capability of the first wireless device;
• transmitting, by the second wireless device to an internet Protocol multimedia subsystem (IMS) network entity, a second SIP REGISTER message comprising a second Contact header field, the second Contact header field comprising the IMS identifier;
• identifying, by the IMS network entity and employing a profile of the first wireless device, at least one mission critical application server (MC AS);
• registering, by the IMS network entity, the first wireless device to the at least one MC AS;
• receiving, by the at least one MC AS from the IMS network entity, a SIP request comprising the IMS identifier for the first wireless device;
• determining, by the at least one MC AS and employing the SIP request and the mission critical video capability, that a mission critical video service can be established;
• and
• transmitting, by the at least one MC AS, the SIP request, to the first wireless device via the second wireless device.