Analysis of a campus-wide wireless network

ABSTRACT

Understanding usage patterns in wireless local-area networks (WLANs) is critical for those who develop, deploy, and manage WLAN technology, as well as those who develop systems and application software for wireless networks. This paper presents results from the largest and most comprehensive trace of network activity in a large, production wireless LAN. For eleven weeks we traced the activity of nearly two thousand users drawn from a general campus population, using a campus-wide network of 476 access points spread over 161 buildings. Our study expands on those done by Tang and Baker, with a significantly larger and broader population.We found that residential traffic dominated all other traffic, particularly in residences populated by newer students; students are increasingly choosing a wireless laptop as their primary computer. Although web protocols were the single largest component of traffic volume, network backup and file sharing contributed an unexpectedly large amount to the traffic. Although there was some roaming within a network session, we were surprised by the number of situations in which cards roamed excessively, unable to settle on one access point. Cross-subnet roams were an especial problem, because they broke IP connections, indicating the need for solutions that avoid or accommodate such roams.

REFERENCES

• 1: Atul Adya , Paramvir Bahl , Lili Qiu, Characterizing Alert and Browse Services of Mobile Clients, Proceedings of the General Track: 2002 USENIX Annual Technical Conference, p.343-356, June 10-15, 2002
• 2: Anand Balachandran , Geoffrey M. Voelker , Paramvir Bahl , P. Venkat Rangan, Characterizing user behavior and network performance in a public wireless LAN, Proceedings of the 2002 ACM SIGMETRICS international conference on Measurement and modeling of computer systems, June 15-19, 2002, Marina Del Rey, California
• 3: Bernard J. Bennington , Charles R. Bartel, Wireless Andrew: experience building a high speed, campus-wide wireless data network, Proceedings of the 3rd annual ACM/IEEE international conference on Mobile computing and networking, p.55-65, September 26-30, 1997, Budapest, Hungary [doi>10.1145/262116.262131]
• 4: R. Boggs and P. Arabasz. The move to wireless networking in higher education. Research Bulletin of the EDUCAUSE Center for Applied Research, April 2002.
• 5: J. Christy. Cisco Systems engineer. Personal communication, March 4, 2002.
• 6: Alex Hills, Wireless Andrew, IEEE Spectrum, v.36 n.6, p.49-53, June 1999 [doi>10.1109/6.769269]
• 7: A. Hills and D. B. Johnson. Seamless access to multiple wireless data networks: A wireless data network infrastructure at Carnegie Mellon University. IEEE Personal Communications, 3(1):56--63, February 1996.
• 8: D. Kotz and K. Essien. ftp://ftp.cs.dartmouth.edu/TR/TR2002-423.pdf Characterizing usage of a campus-wide wireless network. Technical Report TR2002-423, Dartmouth College, March 2002.
• 9: Thomas Kunz , Thomas Barry , James P. Black , Hugh M. Mahoney, WAP traffic: description and comparison to WWW traffic, Proceedings of the 3rd ACM international workshop on Modeling, analysis and simulation of wireless and mobile systems, p.11-19, August 20-20, 2000, Boston, Massachusetts, United States [doi>10.1145/346855.346858]
• 10: Kevin Lai , Mema Roussopoulos , Diane Tang , Xinhua Zhao , Mary Baker, Experiences with a Mobile Testbed, Proceedings of the Second International Conference on Worldwide Computing and Its Applications, p.222-237, March 04-05, 1998
• 11: Charles E. Perkins, Mobile networking in the Internet, Mobile Networks and Applications, v.3 n.4, p.319-334, 1999 [doi>10.1023/A:1019145303706]
• 12: Pablo Stern, Measuring early usage of Dartmouth''s wireless network, Dartmouth College, Hanover, NH, 2001
• 13: Diane Tang , Mary Baker, Analysis of a local-area wireless network, Proceedings of the 6th annual international conference on Mobile computing and networking, p.1-10, August 06-11, 2000, Boston, Massachusetts, United States [doi>10.1145/345910.345912]
• 14: Diane Tang , Mary Baker, Analysis of a metropolitan-area wireless network, Wireless Networks, v.8 n.2/3, p.107-120, March-May 2002 [doi>10.1023/A:1013739407600]

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Wireless communication

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.2 Network Protocols
      C.2.3 Network Operations
          Subjects: Network monitoring; Network management
      C.2.5 Local and Wide-Area Networks

General Terms:
Measurement

Keywords:
802.11, LAN, network analysis, usage characterization