A system, comprising: a processor; a 3D image sensor configured to send image data to the processor; and an interface coupled to the processor and configured to communicate with a device, characterised in that: the processor is configured to initiate a first control session in response to detection of a first recognized initiate gesture performed by a first user, said initiate gesture being detected in response to initial 3D image data obtained from said 3D image sensor, wherein during the first control session, the processor is configured to: identify, using said initial 3D image data, one or more characteristics of said first user to allow said first user to be tracked; detect a first gesture made by the first user based on the image data; identify a first command based on the first gesture, the first command associated with the device; determine based on said identified one or more characteristics of said first user whether the first command is authorized based on a time restriction associated with the first user; responsive to a determination that the first command is authorized, send the first command to the device via the interface; ignore a second recognized command gesture performed by a second user; detect a recognized end gesture made by the first user; and end the first control session in response to the recognized end gesture; wherein the processor is configured to initiate a second control session in response to detection of a second recognized initiate gesture performed by the second user; and wherein during the second control session, the processor is configured to: send a second command via the interface to the device in response to a third recognized command gesture performed by the second user; and ignore a fourth recognized command gesture performed by the first user. a processor; a 3D image sensor configured to send image data to the processor; and an interface coupled to the processor and configured to communicate with a device, characterised in that: the processor is configured to initiate a first control session in response to detection of a first recognized initiate gesture performed by a first user, said initiate gesture being detected in response to initial 3D image data obtained from said 3D image sensor, the processor is configured to initiate a first control session in response to detection of a first recognized initiate gesture performed by a first user, said initiate gesture being detected in response to initial 3D image data obtained from said 3D image sensor, wherein during the first control session, the processor is configured to: identify, using said initial 3D image data, one or more characteristics of said first user to allow said first user to be tracked; detect a first gesture made by the first user based on the image data; identify a first command based on the first gesture, the first command associated with the device; determine based on said identified one or more characteristics of said first user whether the first command is authorized based on a time restriction associated with the first user; responsive to a determination that the first command is authorized, send the first command to the device via the interface; ignore a second recognized command gesture performed by a second user; detect a recognized end gesture made by the first user; and end the first control session in response to the recognized end gesture; wherein the processor is configured to initiate a second control session in response to detection of a second recognized initiate gesture performed by the second user; and identify, using said initial 3D image data, one or more characteristics of said first user to allow said first user to be tracked; detect a first gesture made by the first user based on the image data; identify a first command based on the first gesture, the first command associated with the device; determine based on said identified one or more characteristics of said first user whether the first command is authorized based on a time restriction associated with the first user; responsive to a determination that the first command is authorized, send the first command to the device via the interface; ignore a second recognized command gesture performed by a second user; detect a recognized end gesture made by the first user; and end the first control session in response to the recognized end gesture; wherein the processor is configured to initiate a second control session in response to detection of a second recognized initiate gesture performed by the second user; and wherein during the second control session, the processor is configured to: send a second command via the interface to the device in response to a third recognized command gesture performed by the second user; and ignore a fourth recognized command gesture performed by the first user. send a second command via the interface to the device in response to a third recognized command gesture performed by the second user; and ignore a fourth recognized command gesture performed by the first user.