Engineering Mobile Proxy Design for Wide-Area Wireless

I. INTRODUCTION The vision of a broadly unied and pervasive communica- tion paradigm where people can freely communicate with wide range of devices (phones, PDAs, palmtops etc.) using networks of wired and wireless links is gradually taking shape (3), (11), (12). Applications that will run over a communication infras- tructure composed of heterogeneous links (wired and wireless) will be susceptible to the vagaries of underlying network perfor- mance effects. This might be an outcome of the inexperience in the handling of a completely new wireless network technol- ogy, or integrating diverse network infrastructure, while still re- using the 'staple' (Internet) protocols never attuned for such networks. Manifestation of the network performance effects will result in severe degradation of the application performance, lowering the achievable Quality of Service (QoS) or essentially hindering information access and even impeding data transfer to the end user. In this paper, we focus on how seamlessly we can integrate wide-area wireless networks with the Internet without trading off on performance. The goal is to design and implement a transparent mobile proxy that utilizes novel schemes that yields a better performance and mitigates any existing performance bottlenecks to enable a seamless integration. An integration of wide-area wireless with the Internet is likely to pose many impediments, since very little is known (as of now) on prac- tical performance problems related to networks like GPRS or 3G. While the Internet acts as a testbed for actual measure- ments for wired networks, similar performance measurements pertaining to wide-area wireless technologies will be available only after their wide-scale deployment. Take for instance, Gen- eral Packet Radio Service(GPRS), a packet-based wireless ex- tension of GSM, which is being deployed throughout much of the world. GPRS offers an ìalways onî connectivity to mo- bile users, with a geographical coverage over a wide-area and data rates comparable to that of conventional x ed-line tele- phone modems. This will be soon expected to be followed by the deployment of third generation wireless networks offer-