When you want to be reached on the SIP number, you need to be logged in. But keeping the session up uses data and a lot of battery power. For that reason I chose not to leave the SIP app running, and only use it for outbound calls.
Android phones however have a function called "Google Cloud Messaging for Android", CGM for short. This is the successor to C2DM. It receives a message through the permanent control connection that the phone has with Google. CGM allows 'something connected to the internet' to send something to a phone, without needing an extra connection or using extra power or data.
Now my idea is:
- a home SIP gateway is registered with the Google CGM service
- the phone has a small app that can receive a message and start/login the SIP app
When a call is incoming, the home SIP gateway (or SIP switch, carrier..) sends the CGM message out. Google relays this to the phone, where the SIP app is made to login. It notices the phone is ringing and allows taking the call.
The sending function can be in a home SIP gateway, or in a carrier SIP switch. Features similar to CGM are on other phones. The SIP app can listen by itself to these CGM messages, or there can be an extra app that logs in the desired SIP app. And the SIP app need not be SIP even, you could run Skype at home, send the message when it goes off, and start Skype on the phone: you are reachable on Skype without being logged in all the time.
Basically, a new component in the network that sends the trigger, and a small app that start SIP when needed.
Android phones however have a function called "Google Cloud Messaging for Android", CGM for short. This is the successor to C2DM. It receives a message through the permanent control connection that the phone has with Google. CGM allows 'something connected to the internet' to send something to a phone, without needing an extra connection or using extra power or data.
Now my idea is:
- a home SIP gateway is registered with the Google CGM service
- the phone has a small app that can receive a message and start/login the SIP app
When a call is incoming, the home SIP gateway (or SIP switch, carrier..) sends the CGM message out. Google relays this to the phone, where the SIP app is made to login. It notices the phone is ringing and allows taking the call.
The sending function can be in a home SIP gateway, or in a carrier SIP switch. Features similar to CGM are on other phones. The SIP app can listen by itself to these CGM messages, or there can be an extra app that logs in the desired SIP app. And the SIP app need not be SIP even, you could run Skype at home, send the message when it goes off, and start Skype on the phone: you are reachable on Skype without being logged in all the time.
Basically, a new component in the network that sends the trigger, and a small app that start SIP when needed.
