Wireless devices are used all over the world in a variety of ways. Examples include AM radio, FM radio, cordless...
phones, cellular phones, satellite communications, Wi-Fi and WiMAX communication. These technologies use either a licensed or unlicensed frequency on the wireless spectrum.
Two of the hottest technologies in the market, Wi-Fi and WiMAX, are experiencing an enormous increase in deployments, products and services. This article will examine the difference between the technologies as it relates to standards development and solution positioning.
Wi-Fi technology has been around for quite some time in the form of 802.11b WLAN solutions that have evolved to include both 802.11a and 802.11g. The primary difference between the 802.11 technologies is the wireless spectrum used and the bandwidth supported. In the industry, 802.11 technologies are sometimes referenced as technologies for carpeted areas -- inside building wireless solutions, for example. Generally, Wi-Fi is a one base station (access point) with many clients (PCs, laptops, PDAs); it has a limited coverage area but relatively high bandwidth (up to 54Mbps).
WiMAX (which stands for Wireless Interoperability of Microwave Access) is a relatively new technology based on IEEE 802.16 standards. WiMAX provides an international standard for fixed broadband wireless access with planned evolution to mobile. The WiMAX Forum is driving standards for conformance and interoperability to realize a carrier-class fixed wireless solution. Some other aspects are that WiMAX:
- Operates very similarly to Ethernet (e.g., Layer 2) using VLAN tags
- Is experiencing broad industry support
- Can utilize either licensed or unlicensed frequencies
- Can be considered as an alternative to last-mile access (T1/DSL/Cable, etc.)
- Has 10 Mbps capacity per channel
- Has a coverage area of up to five miles for non-line of sight
Traditionally, when organizations wanted to provide WLAN access outside, they would deploy traditional Wi-Fi (802.11 a/b/g) in a secure, protected enclosure. In addition, wireless bridging was used to connect facilities and campuses with line-of-sight, point-to-point connections. With the advent of WiMAX technology, the following capabilities are provided:
- Fixed wireless connectivity
- Backhaul to core networks for distributed Wi-Fi (e.g., hotspots)
- Multi-building campus interconnection
- Diverse connections using relatively cheap wireless
- Portable wireless connectivity
- Hotspot coverage in large municipal areas (such as the City of Philadelphia)
- Mobile wireless connectivity
- Mobility and roaming capabilities while on the move
- First responders
- Package delivery
- Corporate field agents
Certified WiMAX products began hitting the market in late 2005; since then, a multitude of vendors (see WiMAX Forum for vendor lists) have been touting the capabilities described above. As with most emerging technologies, however, vendors may claim that their products comply with industry standards, but interoperability testing is strongly recommended when mixing solutions.
In summary, WiMAX technology represents a quantum leap in the ability to propagate wireless connectivity with acceptable speed, allowing the technology to be used as a business class access technology. This is driving tremendous momentum in the deployment of wireless access technology outside the traditional carpeted areas.
About the author:
Robbie Harrell (CCIE#3873) is the National Practice Lead for Advanced Infrastructure Solutions for SBC Communications. He has more than 10 years of experience providing strategic, business and technical consulting services. Robbie lives in Atlanta and is a graduate of Clemson University. His background includes positions as a principal architect at International Network Services, Lucent, Frontway and Callisma.