A power efficient solution to the large interference range problem in ad hoc networks

摘要

Due to the mismatch between the transmission range and interference-vulnerable range, the reception at a receiving node in a wireless network could still be interfered by a sending node beyond the coverage of its clear-tosend (CTS). This is the so-called large interference range problem. It is a common problem in real environments but overlooked by the standards and related studies. The large interference range problem could lead to transmission control protocol (TCP) instability and TCP unfairness, especially in case of multi-hop transmission. There exist research works devoted to this issue. However, more power consumption was incurred at the same time. For a power-efficient solution to this problem, a novel scheme, named power control interference avoidance (PCIA), is developed and presented in this article. The proposed scheme decouples control channel from data channel and use different power level in the transmission of control frames and data frames. By doing so, the large interference problem can be effectively avoided, while retaining a high level of power efficiency. The feasibility and effectiveness of the proposed scheme had been validated by an analytic study on a simplified model and a series of simulations. As revealed in the simulation results, the proposed PCIA scheme outperforms conservative CTS reply (CCR) and IEEE 802.11 in many aspects, including data corruption ratio and power efficiency.