Extracting More Capacity from Multi-channel Multi-radio Wireless Networks by Exploiting Power

Transmission power plays a crucial role in the design and performance of wireless networks. The issue is therefore complex since an increase in transmission power implies that a high quality signal is received at the receiver and hence an increase in channel capacity. Conversely, due to the shared nature of the wireless medium an increase in transmission power also implies high interference in the surrounding region and hence a quadratic reduction in the capacity of wireless networks. Recent literatures indicate that employing multiple channels can mitigate the negative effects of wireless interference and thus greatly improve the overall network capacity. Therefore, it is worth investigating the effect of exploiting power on the capacity of multi-channel multi-radio (MC-MR) wireless networks. Specifically, in this paper we address the following questions: (a) Can we maximize the capacity of MC-MR wireless networks by exploiting power? (b) Under what criteria can we increase the transmission power of the nodes in a MC-MR network? When n nodes each with m half-duplex interfaces are optimally deployed in a torus of unit area, traffic patterns are optimally assigned, each transmission's range is optimally chosen and in the presence of c channels, we show that in contrast to the setting where nodes transmit at minimum power level Po the transport capacity, measured in bit-meters per second, of MC-MR network exploiting power is increased by Θ(
_c
min
) in region c
_min
<; c <; mn/2 and by Θ(n) in region c ≥ mn/2 when nodes tune to transmit power level of P
₀
(c/
_c
min
)
^α/2
and P
₀
n
^α/2
respectively-where c
_min
is the minimum number of channels required to achieve conflict-free transmissions in a network. Our analysis also sheds light into several insights that designers may want to consider to improve the performance of energy-efficient bandwidth-constrained wireless networks.