Optimal capacity of hybrid unicast-broadcast networks for mobile TV services

This paper studies the optimal broadcast coverage radius in a hybrid network from the perspective of network planning. The hybrid network is composed of a unicast and broadcast systems which cooperate to deliver linear services on portable and mobile devices. First we define a hybrid approach in which the coverage radius of the broadcast network is adjusted according to the distribution of the users in the service area. Then, by applying convex optimization methods, we derive a closed-form expression of the optimal broadcast coverage radius that maximizes the average capacity per user in the hybrid network. The results show that the closed-form expression of the broadcast coverage radius is in good agreement with the simulation results, which validates the theoretical approach.