System and method for controlling surveillance cameras
A system and method for controlling surveillance cameras is enclosed. In the system, a surveillance camera system includes surveillance cameras configured as VoIP server endpoints. The surveillance cameras receive messages from client devices such as mobile user devices and computer workstations functioning as VoIP client endpoints. The client devices establish a voice communications channel with the surveillance cameras for receiving and controlling one or more streams of image data sent by the surveillance camera over the voice communications channel to the client device. In a preferred embodiment, the voice communications channel includes a control session based on Session Information Protocol (SIP) and a data channel that is based on Real time transfer protocol (RTP). The data channel preferably operates in half duplex mode, which limits the potential for collisions on the data channel when the surveillance cameras are transmitting their image data to the client devices.
1. A system delivering image data, comprising:
a surveillance camera;
a client device that establishes a voice communications channel for receiving and controlling one or more streams of image data generated by the surveillance camera; and
an application server of the surveillance camera that includes:
a Session Initiation Protocol (SIP) layer implementing SIP for establishing a control session of the voice communications channel, wherein the SIP layer automatically answers a call from the client device based on the client device being authenticated and the control session controls the one or more streams of image data sent by the surveillance camera to the client device in response to the call; and
a Real Time Protocol (RTP) layer implementing RTP for establishing a half duplex data channel of the voice communications channel, for sending the one or more streams of image data to the client device.
2. The system of claim 1 , wherein the client device controls the one or more streams of image data via the control session.
3. The system of claim 1 , wherein the control session authenticates the client device.
4. The system of claim 1 , wherein the image data of the one or more streams of image data are stored within the surveillance camera.
5. A method for dclivcringreceiving image data from a surveillance camera, the method comprising:
establishing, with the surveillance camera, a voice communications channel for receiving one or more streams of image data generated by the surveillance camera;
establishing, with a Session Initiation Protocol (SIP) layer of an application server of the surveillance camera, a control session of the voice communications channel in response to a call automatically answered by the SIP layer, wherein the control session controls the one or more streams of image data received from the surveillance camera and a Real Time Protocol (RTP) layer implementing the RTP for establishing a half duplex data channel of the voice communications channel;
receiving, via the half duplex data channel of the voice communications channel, the one or more streams of frames of image data originating from the surveillance camera over the voice communications channel using the SIP layer.
6. The method of claim 5 , further comprising the data channel referencing a session ID of the control session.
7. The method of claim 5 , further comprising authenticating to the surveillance camera via the control session.
8. The method of claim 5 , wherein controlling the one or more streams of frames of image data comprises the client device sending control messages to the surveillance camera via an IP based control session of the voice communications channel.
9. The method of claim 5 , wherein receiving the one or more streams of frames of image data sent by the surveillance camera comprises the client device receiving the streams of the frames of image data from the surveillance camera over a data channel of the voice communications channel.
10. A method for a mobile user device to access image data from a surveillance camera, the method comprising:
configuring the mobile user device as a voice over Internet protocol (VoIP) client endpoint;
configuring the surveillance camera as a VoIP server endpoint that automatically answers a call from the mobile user device based on the mobile user device being authenticated;
establishing, based at least in part on the call, a Session Initiation Protocol (SIP) based control session with the surveillance camera;
receiving, by the mobile device, a frame of image data over a half duplex data channel, where the frame of image data is included within Real time Transport Protocol (RTP) packets sent from the surveillance camera;
rendering, the mobile user device, the frame of image data on a display screen of the user mobile device; and
processing another frame of image data to be sent over the half duplex data channel to the mobile user device by receiving the another frame of image data within Real time Transport Protocol (RTP) packets sent from the surveillance camera.