Distributed power control over multiple channels for ad hoc wireless networks

Abstract

In this paper, we investigate the deficiency of uncontrolled asymmetrical transmission power over multiple channels in ad hoc environments. We further propose a novel distributed transmission power control protocol called the distributed power level (DPL) protocol for multi‐channel ad hoc networks without requiring clock synchronization. Specifically, different transmission power levels are assigned to different channels, and nodes search for an idle channel on the basis of the received power so that the maximum allowable power of the preferred data channel is larger than or equal to the received power. If the most preferred channel of the least maximum power is busy, the nodes are able to select the next channel and so forth. As a result, interference is reduced over channels because the nodes that require higher transmission power are separated from interfering with the nodes that require lower transmission power. Two transmission power control modes are introduced for DPL: symmetrical and asymmetrical. For the symmetrical DPL protocol (mode), nodes transmit at the same power level assigned to the selected channel. On the other hand, for the asymmetrical DPL protocol, nodes are allowed to transmit at a lower or equal power level that is assigned to the selected channel. Extensive ns‐2‐based simulation results are presented to demonstrate that the proposed protocols can enhance the network throughput compared with the existing uncontrolled asymmetrical transmission power protocol. Copyright © 2012 John Wiley & Sons, Ltd.

Directional Medium Access Control (MAC) Protocols in Wireless Ad Hoc and Sensor Networks: A Survey

“…Although directional antennas have key benefits, they also lead to key problems like single-/ multi-channel directional hidden/exposed terminals, deafness and neighborhood, head-of-line blocking, and MAC-layer capture [2][3][4][5][6][7][9][10][11] which need to be overcome.…”

“…An example is shown in Figure 12. The reason for changing channel may be to due to a primary user becoming active in the original channel for dynamic spectrum access scenario [9]. Multi-channel exposed terminals problem is a scenario similar to that for single-channel exposed terminal problem, except that it is in every channel in the multiple channels, for example in non-control-channel-based multi-channel DMAC protocols.…”

“…On the other hand, multi-channel DMAC protocols lead to higher throughput as compared to single-channel DMAC protocols. The idea in reference [9] can be applied to this DMAC protocol too. Reference [9] is a variant of such an omni-directional MAC protocol.…”

“…The idea in reference [9] can be applied to this DMAC protocol too. Reference [9] is a variant of such an omni-directional MAC protocol. The key idea of this multi-channel power-controlled DMAP protocol is to differentiate allowable transmission power levels among channels [9].…”

“…Reference [9] is a variant of such an omni-directional MAC protocol. The key idea of this multi-channel power-controlled DMAP protocol is to differentiate allowable transmission power levels among channels [9]. That is, different transmission power levels are assigned to different channels [9].…”