Abstract:

An adaptive scheme of power saving is proposed for the voice over IP (VoIP) services, which are based on the adaptive multirate (AMR) speech codec in the IEEE 802.16 systems. This scheme determines whether both of the uplink and downlink services enter the silence period through examining the information of speech frames in the twoway conversation periodically. Based on this, the parameters of the power saving mode are modified adaptively. Then the performance of the proposed scheme in terms of energy saving, drop rate and signaling overhead of system is analyzed. In addition, the simulation experiments are implemented. Through the theoretical analysis and simulation results, the new scheme shows that it reduces the energy consumption by more than 13.4% based on guaranteeing the drop rate of users compared with the conventional scheme.

Key words: 802.16 systems;scheme of power saving;VoIP;AMR speech codec