General Description

According to the WiMAX Forum, Worldwide Interoperability for Microwave Access -- or WiMAX -- is a "standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL."

Intel describes mobile WiMAX as a forth generation (4G) wireless technology delivering "low-cost, open networks and is the first all IP mobile Internet solution enabling efficient and scalable networks for data, video and voice."  Intel believes that mobile WiMAX "will do for broadband Internet access what the cell phone did for telephone service -- give you access to the Internet while on the move." (from Intel's Mobile WiMAX brochure.)

Applications / Standards

• Fixed WiMAX: Enterprises can either purchase fixed WiMAX technology for use in their own private network (e.g., a point-to-point wireless connection between two buildings) or can purchase fixed WiMAX service from a wireless Internet service provider (WISP) like NetX.
• Nomadic WiMAX: A user moves from location to location but communicates only while stationary.  A good example is a repairman who needs high-speed network access while parked at a customer location but not while driving.
• Mobile WiMAX: Provides communication while the user is in transit.  (WiMAX tutorial, SearchMobileComputing.com)

WiMAX technology and applications are based on IEEE 802.16 standards, collectively called "Broadband Wireless Metropolitan Area Network (WirelessMAN).  The family includes the original standard: 802.16-2004 (Fixed WiMAX); and 802.16e-2005 (Mobile WiMAX).

Collectively, 802.16 standards specity:

• Range: Up to 30-mile radius from base station
• Speed: Up to 70 Mbps
• Line-of-sight (LOS): Not needed between user and base station
• Frequency bands: 2 to 11 GHZ (802.16-2004) and 10 to 66 GHz (802.16e-2005); licensed and unlicensed spectrum)

Forms of Service

• Non-Line-of-Sight (NLOS) Service: Also described as "super Wi-Fi"; in this mode, WiMAX uses a lower frequency range - 2 GHz to 11GHz; lower-wavelength transmissions are not as easily disrupted by physical obstructions -- they are better able to diffract, or bend, around obstacles.  NetX transmits at a licensed frequency of 3.5 GHz.
• Line-of-Sight (LOS) Service: An antenna points straight at the WiMAX tower from a rooftop or pole.  The line-of-sight connection use higher frequencies.  At higher frequencies, there is less interference and more bandwidth allowing WiMAX to achieve its maximum range.  NetX transmits at a frequency of 5.4GHz. 

WiMAX vs Wi-Fi

WiMax can produce a wireless cloud connectivity to an entire city using just a few base stations and is emerging as a viable alternative to Wi-Fi.  A single WiMAX tower can provide broadband to a far bigger geographic area than Wi-Fi hotspots, and can provide mobile broadband as well to vehicles.

1. Wi-Fi
• Range: 100 yards, covers a coffee shop, one floor of an office building, one home
• Throughput: 11 Mbps
• Security: Limited
• QoS: Limited
2. WiMAX
• Range: 7-10 miles, covers a small city with one base station
• Throughput: 72 Mbps
• Security: Multi-level encryption (defense department level security)
• QoX: Dynamic bandwidth allocation, good for voice & video

WiMAX is a "long range system" that uses licensed or unlicensed spectrum to deliver a point-to-point connection to the Internet from an ISP to an end user.  Wi-Fi is a "short range system" that uses unlicensed spectrum to provide access to a network, typically covering only the network operator's own property.  "If WiMAX provides services analogous to a cellphone, WiFi is more analogous to a cordless phone."  (Broadband Wireless Exchange Network).  "The biggest difference [between WiMax and Wi-Fi] isn't speed; it's distance." (HowStuffWorks.com)

[information obtained from Knight Center of Digital Excellence website]