Multi-Channel, Multi-Radio in Wireless Mesh Networks

Decreasing hardware prices enables increased performance in wireless networks to a low cost. By adding an extra WLAN radio card to existing single radio network platforms, the possibility to utilize additional frequencies arise and opens the world of multi-channel, multi-radio (MCMR). In this report, we investigate different approaches to make as good use of MCMR as possible. A hybrid technique using two radios, one receiving data and the other transmitting, is chosen and implemented. This requires a user-space application, modifications to the wireless driver and the development of a Linux kernel bonding module handling the communication between user-space and drivers. Test results shows that the chosen method increase performance substantially compared to the standard single-channel, single-radio setup, which makes fur- ther development interesting as new faster wireless techniques becomes standard. Fallande hardvarupriser gor det mojligt att till ett lagt pris oka prestandan i tradlosa natverk. Genom att utnyttja tva WLAN-kort istallet for ett i befintliga plattformar oppnar sig en varld av mojligheter inom multi-channel, multi-radio (MCMR). I rapporten undersoker vi olika metoder for att implementera MCMR. Metoden som implementeras gar kortfattat ut pa att ett av de tva radiokorten tar emot data och det andra skickar data. For att gora detta mojlighet kravs en applikation, modifieringar av drivrutiner samt utvecklandet av en bondingmodul i Linuxkarnan vars uppgift ar att skota kommunikationen mellan applikation och drivrutiner. Testresultaten visar att hastigheten under olika forhallanden okar patagligt i jamforelse med vanlig single-channel, single-radio, vilket gor fortsatt utveckling intressant i takt med att nya snabbare tradlosa tekniker blir standard.