Wi-Fi and Wi-Max Coverage Predictions

Comparison of WiMax and Wi-Fi

Unfortunately these terms are often used interchangeably, but the precise meaning of both are distinct.  Possibly due to the fact both WiMAX and Wi-Fi begin with the same two letters, and are based upon IEEE standards beginning with 802., and both have a connection to wireless connectivity and the Internet, comparisons and confusion between the two are frequent.  They generally operate in either the 2 GHz or the 5 GHz band.  Despite these ostensible similarities, both standards are aimed at different applications.  A very brief explanation of the distinctions are provided here. 

• WiMAX is defined as Worldwide Interoperability for Microwave Access by the WiMAX Forum.  WiMAX is a long range (many kilometers) system that uses licensed or unlicensed spectrum to deliver a point-to-point connection to the Internet from an ISP to an end user. Different 802.16 standards provide different types of access, from mobile (analogous to access via a cellphone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.)  The bandwidth and reach of WiMAX make it suitable for the following potential applications:
  • Connecting Wi-Fi hotspots with each other and to other parts of the Internet.
  • Providing a wireless alternative to cable and DSL for last mile (last km) broadband access.
  • Providing high-speed data and telecommunications services.
  • Providing a diverse source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
  • Providing nomadic connectivity

   

• Wi-Fi, popularly known as an acronym for wireless fidelity (see below for origin), was originally a brand licensed by the Wi-Fi Alliance to describe the embedded technology of wireless local area networks (WLAN) based on the IEEE 802.11 specifications. Use of the term has now broadened to generically describe the wireless interface of mobile computing devices, such as laptops in LANs. Wi-Fi is now increasingly used for more services, including Internet and VoIP phone access, gaming, and basic connectivity of consumer electronics such as televisions, DVD players, and digital cameras. More standards are in development that will allow Wi-Fi to be used by cars on highways in support of an Intelligent Transportation System to increase safety, gather statistics, and enable mobile commerce (see IEEE 802.11p). Wi-Fi and the Wi-Fi CERTIFIED logo are registered trademarks of the Wi-Fi Alliance - the trade organization that tests and certifies equipment compliance with the 802.11x standards.

  Wi-Fi is a shorter range (range is typically measured in hundreds of meters) system that uses unlicensed spectrum to provide access to a network, typically covering only the network operator's own property. Typically Wi-Fi is used by an end user to access their own network, which may or may not be connected to the Internet. If WiMAX provides services analogous to a cellphone, Wi-Fi is more analogous to a cordless phone.   Due to the ease and low cost with which Wi-Fi can be deployed, it is sometimes used to provide Internet access to third parties within a single room or building available to the provider, sometimes informally, and sometimes as part of a business relationship. For example, many coffee shops, hotels, and transportation hubs contain Wi-Fi access points providing access to the Internet for patrons.

SoftWright's Terrain Analysis Package Software (TAP)^tm is used by system designers to establish a high confidence level in the adequacy of system coverage from specific nodes on a system.  Wi-Fi coverage is not have a specific application from TAP.  Due to the fact that Wi-Fi signal levels are of very low radiated power most systems are limited to coverage within a few hundred feet it is, therefore, not modeled with TAP.  However, Wi-Max systems are much larger in scale and impact of topography is very much a part of the predictive signal level modeling.  In these types of systems, many system designers employing TAP use the Longley-Rice propagation module.   With TAP the coverage from access points and between access points can be easily modeled.  The designer must use the appropriate frequency band for the particular application, reliable antenna radiation patterns and the normal technical details required for all fixed based transmitting facilities.

Reference material:

Dodd, Annabel Z., The Essential Guide to Telecommunications, Fourth Edition. Upper Saddle River. NJ: Prentice Hall, :2006. (ISBN 0-13-148725-6)

http://en.wikipedia.org/wiki/Wifi

http://en.wikipedia.org/wiki/Wi-max

(20071107) Copyright 2007 by SoftWright LLC, Aurora, Colorado USA