Transmission Power Control for Multiple Access Wireless Packet Networks

Multiple access-based collision avoidance MAC protocols have typically used fixed transmission power, and have not considered power control mechanisms based on the distance of the transmitter and receiver in order to improve spatial channel reuse. In this paper, we motivate transmission power control and investigate the challenges involved in implementing power control in multiple access wireless packet networks. For this work, we focus on wireless ad-hoc networks, where the links connecting sourcedestination pairs are all wireless. Power control has been implemented in cellular networks such as CDMA (code division multiple access) for quite some time now. However, these protocols depend on centralized control (i.e. base stations) and duplex communications that are not inherently present in wireless multiple access packet networks. Our simulation results show that implementing power control in a multiple access environment can improve the throughput performance of the non-power controlled IEEE 802.11 by a factor of 2, thus providing a compelling reason for migrating to a new power controlled multiple access wireless MAC protocol standard.