Americas

  • United States
by Bob Friday

Will wireless work with heavy traffic?

Opinion
Jun 30, 20032 mins
Network SecurityWi-Fi

Q. How do I build a wireless LAN that supports converged voice/data services?

How do I ensure that my WLAN will continue to perform optimally under heavy traffic load?

– Mark, New York

 This is a great question, Mark, because it highlights one of the main reasons why wireless networking is so different from wired networking.  In a traditional LAN environment you can “throw bandwidth at the problem” by ordering larger circuits and installing larger boxes.  This is not viable in a wireless environment, because a wireless system uses the airwaves as the physical medium, which is a fixed resource.  So you cannot simply “buy more frequency” when network congestion becomes a problem.  In the U.S., for example, there is only 83.5 MHz (three non-overlapping channels) available in the 2.4 GHz band (802.11b), and 300 MHz (13 non-overlapping channels) in the 5 GHz band (802.11a).  Even 802.11g, which increases throughput to 54M bit/sec, must deal with the limitation of having only three channels available.  Therefore, to address system capacity and plan for future user growth, IT managers should seriously consider deploying dual-band networks (802.11b/g and 802.11a) to ensure their wireless networks are not quickly overwhelmed by success.

Many RF scientists, such as myself, have built careers around developing better modulation methods, antennae technology and radio resource algorithms to maximize the utilization of the available RF bandwidth.  While the 802.11 standard effectively addresses many of these issues, individual WLAN systems should incorporate their own radio resource algorithms to optimize the usage of the air space.  More specifically, algorithms should be implemented that dynamically handle channel assignment, power control, antennae patterns, and interference detection/avoidance. 

Without radio resource algorithms, large-scale wireless networks would be paralyzed under heavy traffic load.  Imagine what would happen to a cellular network, for example, if it did not have the intelligence to accommodate times of peak usage?  The same intelligence is required in a wireless LAN – especially if you want it to support voice, video and other business-critical applications. With the appropriate algorithms in place, your WLAN will intelligently adjust to traffic load increases to ensure the best network performance all the time. This will make your users happier, and extend the life of your WLAN.