Voice over WiFi: on fabricating an open access neighbourhood wireless local loop for telecommunication

Abstract

This project embraces the use of IEEE 802.11 wireless technologies (Wi-Fi) in provision of IP telephony to desperate communities. It examines the legislation surrounding both the technology and the application of it while documenting the design and implementation of a Wi-Fi based local loop communication network. The most compelling objectives of the project were; to get an in-depth understanding of IEEE 802.11 wireless LAN capabilities for voice, to design a wireless networking model to enable terminating of voice communications and to implement a voice communication system to provide sustainable and cost effective access to telecommunication services. A number of steps were followed in the design and implementation of the communication system and these included analysing user requirements, designing the system, and implementing the components which were deemed useful to the smooth operation of the system. From the analysis, we see that voice places a unique requirements on WLAN that are different from data applications. Issues like quality of service, end-to-end delay, jitter for VoIP packets in order to provide optimal audio are some of the challenges of routing voice over wireless networks. Also the very nature of operation of wireless networks provides a bandwidth cap hence presenting a limit of how many simultaneous calls that can be routed per wireless channel. It was evident that WLAN support for VoIP also presents operational challenges not faced by traditional wireless networks like GSM. The wireless medium is a shared resource and when coupled with the flexibility of deployment, reliable service must be maintained at the radio frequency layer as well as at the application layer which increases on deployment challenges. From the infrastructure point of view, coupled with the geographical limitation of WLANs we come up with a design of a wireless networking model to enable terminating of voice communications in desperate environment like rural areas.The IEEE 802.11 specifies two modes of operation which are ”Infrastructure” or ”Ad-hoc” modes but these have limitations so we had to come up with a networking remedy which is decentralized, relatively inexpensive,very reliable and resilient. Many questions and possible research areas were encountered; in the authors opinion, the most interesting ones for future research are these; Coming up with a mechanism of improving on bandwidth consumption by reducing on the capacity requirement per voice call over Wi-Fi networks, repeating this implementation on different infrastructure setup for example on a different networking technology for example the emerging WIMAX technology, and coming up with an efficient algorithm which can be used in number discovery.