Network Lifetime Maximization in Mobile Visual Sensor Networks

A mobile visual sensor network has a potential to create impacts in many applications in the society; however, it remains a challenge to keep the network lifetime as long as possible with limited onboard energy. Based on our previous work, mobility can be exploited to improve network lifetime significantly for data-intensive mobile sensor networks. In a visual sensor network, besides heavy data transmission, the video encoding process consumes a considerable portion of the energy. With the quality of visual sensing in mind, this paper investigates a joint design method to simultaneously design mobility, source data rate, routing, and video encoding strategies for robotic visual sensor nodes to improve the lifetime of a mobile visual sensor network. We formulate the network lifetime problem as a nonlinear, non-convex, optimization problem, and we propose to solve it distributively by a series of convex approximations and a proposed novel algorithm. Computer simulations were conducted to verify its quick convergence to the solution and the improvement of the lifetime of the network using mobility.