Designing interference-aware network selection protocol for WLAN mobile devices

Due to increasing demand of wireless services for portable devices, numerous efforts to enhance wireless network performance have been made for decades. Many researchers were focused on the word ‘seamless’ for sustaining connectivity during a handover process, but wireless performance of destined access point (AP) is rarely considered. This paper analyses thoroughly usual network connection behaviour, captures several problems from the procedure, and proposes interference-avoiding selection (IAS) mechanism that associates a wireless AP, which is expected to perform better than other APs nearby. Proposed selection mechanism concentrates on utilization of each channel within one hop range and received signal strength measured by incoming beacons from surrounding APs. Possible interference by adjacent channels is also considered in this paper. Moreover, unlike any other prior selection mechanism, IAS protocol does not require any modification on existing communication protocols, extra delay to evaluate surrounding APs, and support from huge data server that collects information and derives quality of surrounding APs ahead of the selection phase. Various analysis and performance evaluations are progressed using OPNET, ns2, and Android programming, and the evaluation results showed that proposed selection mechanism can increase the throughput of original selection mechanism by more than 55% in average.