Experimental Evaluation of Techniques to Lower Spectrum Consumption in Wi-Red

Seamless redundancy layered atop Wi-Fi has been shown able to tangibly increase communication quality, hence offering industry-grade reliability. However, it also implies much higher network traffic, which is often unbearable as the wireless spectrum is a shared and scarce resource. To deal with this drawback, the Wi-Red proposal includes suitable duplication avoidance mechanisms that reduce spectrum consumption by pre- venting transmission on air of inessential frame duplicates. In this paper, the ability of such mechanisms to save wireless bandwidth is experimentally evaluated. To this purpose, specific post-analysis techniques have been defined, which permit assessment on a simple testbed that relies on plain redundancy and require no changes to the adapters' firmware. As the results show, spectrum consumption decreases noticeably without communication quality is impaired. Further saving can be obtained if a slight worsening is tolerated for latencies.