ROSALNet: rural opportunistic spectrum aware low cost network

We present ROSALNet, a low-cost TDM mesh network which is designed to opportunistically exploit TV white spaces (TVWS) to provide broadband Internet connectivity to remote rural areas. Exploiting TV white spaces for broadband connectivity can potentially bring down the cost of wireless networks to a more affordable level. ROSALNet is implemented on commodity hardware using the open-source OpenWrt operating system. A single mesh node currently costs US$330, which is significantly cheaper than competing TVWS commercial solutions. ROSALNet can opportunistically use spectrum by looking up a white space database and by performing spectrum sensing. Our experiments with ROSALNet on a university campus demonstrate the superior coverage possible with TVWS compared to 2.4GHz. ROSALNet modifies an existing TDM mesh implementation originally designed to use WiFi bands, called FRACTEL, thereby inheriting its attractive features of low-latency and low jitter. Results from a lab testbed consisting of 4 nodes show that ROSALNet can provide an aggregate throughput of 11Mbps, which is sufficient to support triple play services.