etx_report

Bryan Cribbs
29 Jun 2004

For this benchmark, we've completed the core ETX module functionality, implemented as an extension to the HSLS daemon. As described in the ETX protocol spec[1], ETX computes metrics for each link in a network, and HSLS uses these metrics to determine best paths for data transfers.

The ETX metric holds several promising properties for wireless mesh networks. By nature 802.11 is a lossy medium, and so a shorter path (by hop count) may not be as desireable as a longer hop path with a lower expected transmission count.

The sensitivity of the ETX metric is configurable, allowing it to configured for highly volatile networks, such as a swarm of conference attendees with laptops, or for a more stable environment, such as a rooftop net.