Multi-radio diversity in wireless networks

Abstract

This paper describes the Multi-Radio Diversity (MRD) wireless system, which uses path diversity to improve loss resilience in wireless local area networks (WLANs). MRD coordinates wireless receptions among multiple radios to improve loss resilience in the face of path-dependent frame corruption over the radio. MRD incorporates two techniques to recover from bit errors and lower the loss rates observed by higher layers, without consuming much extra bandwidth. The first technique is frame combining, in which multiple, possibly erroneous, copies of a given frame are combined together in an attempt to recover the frame without retransmission. The second technique is a low-overhead retransmission scheme called request-for-acknowledgment (RFA), which operates above the link layer and below the network layer to attempt to recover from frame combining failures. We present an analysis that determines how the parameters for these algorithms should be chosen.We have designed and implemented MRD as a fully functional WLAN infrastructure based on 802.11a. We evaluate the MRD system under several different physical configurations, using both UDP and TCP, and measured throughput gains up to 3× over single radio communication schemes employing 802.11's autorate adaptation scheme.

Achievable Capacity Limit of High Performance Nodes for Wireless Mesh Networks

“…As a result, many IEEE 802.11 interface cards can be switched from one channel to another, albeit at the cost of a switching delay. Moreover, the advantage of eliminating frame losses due to path-dependent (e.g., multipath fading effects), locationdependent (e.g., noise effects), and statistically independence between different receiving radios can be achieved by using multi-radio diversity principle (Miu, Balakrishnan & Koksal, 2007). The idea is that even when each individual reception of a data frame is erroneous, it might still be possible to combine the different versions to recover the correct version of the frame.…”

A survey on dependability in Body Area Networks

“…By equipping the aggregator or sensors with multiple radio transceivers, the path diversity to the destination would be vastly improved [17] [21]. These can include IEEE 802.11 (a, b, g, n), Bluetooth, GPRS, EDGE, and UMTS.…”