Transmission rate adjustment algorithm for power-limited wireless multicast network

In cellular type of network, many attentions on transmission power have been paid to save energy as the growth of the telecommunication networks become remarkably large. In spite of concerns on transmission power, the multicast service still has to be provided with full of transmission power in order for even the worst channel user to be served. When the peak power that a transmitter can reach is limited, sometimes the transmitter is not able to provide service without transmission failure, namely, power-limited environment. In this paper, we analyzed the effects of the power limitation and the power deficiency. Our analysis presents the mathematical relationship between the transmission failure probability and given transmission power in the wireless multicast network, whereas the recent work shows the transmission failure probability only when the power is sufficiently supplied. The results are verified by numerical simulation. As an extension of the analysis, we also propose an algorithm for the given problem that a network suffers from the power-limited situation. This algorithm searches for the most proper transmission rate when the system operator has the outage policy, a guarantee of the minimum rate of successful transmission, in the power-limited situation. In case there is no policy, the algorithm contains an optimization problem which maximizes the Multicast Group Utility at given power. The group utility function is defined prior to the optimization problem. The simulation confirms that in the power-limited environment, the system operator can always find an adjusted transmission rate at which the group utility is maximized.