Anand Balachandran

Characterizing user behavior and network performance in a public wireless LAN

This paper presents and analyzes user behavior and network performance in a public-area wireless network using a workload captured at a well-attended ACM conference. The goals of our study are: (1) to extend our understanding of wireless user behavior and wireless network performance; (2) to characterize wireless users in terms of a parameterized model for use with analytic and simulation studies involving wireless LAN traffic; and (3) to apply our workload analysis results to issues in wireless network deployment, such as capacity planning, and potential network optimizations, such as algorithms for load balancing across multiple access points (APs) in a wireless network.

Secure wireless Internet access in public places

We have built a network, called the CHOICE network, which globally authenticates users and then securely connects them to the Internet via a high-speed local area wireless network. Our network provides easy-to-use, individual-centric, service-oriented wireless Internet access in places other than the traditional corporate offices and homes. Our architecture is hardware and protocol agnostic and is built on an easily deployable software module called the protocol for authorization and negotiation of services or PANS. PANS provides authorization, access, privacy, security, policy enforcement, quality of service (QoS) and accounting. In this paper, we describe PANS in detail. We discuss our system design and operation, implementation and performance. We evaluate PANS and show that it is scalable and secure. Our network has been deployed and is operational at a local mall in Bellevue, Washington.

Wireless hotspots: current challenges and future directions

In recent years, wireless Internet service providers (WISPs) have established Wi-Fi hotspots in increasing numbers at public venues, providing local coverage to traveling users and empowering them with the ability to access email, Web, and other Internet applications on the move. In this paper, we observe that while the mobile computing landscape has changed both in terms of number and type of hotspot venues, there are several technological and deployment challenges remaining before hotspots can become an ubiquitous infrastructure. These challenges include authentication, security, coverage, management, location services, billing, and interoperability. We discuss existing research, the work of standards bodies, and the experience of commercial hotspot providers in these areas, and then describe compelling open research questions that remain.