Wimax - Worldwide Interoperability for Microwave Access

Worldwide Interoperability for Microwave Access (WiMax)

Danielle LeLievre, Marcos Lopez, Alex Ventura, Jorge Colon, and Ruth Martinez

University of Phoenix

NTC/360

Network and Telecommunication Concepts

Elizabeth Teffner

May 06, 2006

Worldwide Interoperability for Microwave Access, most commonly referred to as WiMAX, "is a standards-based wireless technology that provides high-throughput broadband connections over long distances" (WiMAX, 2006, ¶ 1). The standard approved by the Institute of Electrical and Electronics Engineers (IEEE) references WiMAX as 802.16 (WiMAX, 2006, ¶ 1). The 802.16 standard uses a point-to-multipoint infrastructure design ("Intel and WiMAX," 2006, ¶ 15). WiMAX combines "the speed and security of a broadband connection but with the lower cost and convenience of having no wired infrastructure that's needed for cable modems or DSL connections" (Walton, 2006, ¶ 6).

WiMAX is comparable to that of Wi-Fi in the fact that it provides users with internet connection (WiMAX, 2006, ¶ 2). However, there are substantial differences between the two. Wi-Fi provides a connection speed that can handle up to 54 Mbps. WiMAX can transmit speeds up to 70 Mbps (Brain & Grabianowski, 2006, ¶ 13). The major distinction between Wi-Fi and WiMAX is the distance (Brain & Grabianowski, 2006, ¶ 14). Wi-Fi provides a user with internet connection when an access point is within proximity (Wi-Fi, 2006, ¶ 2). This coverage is usually only within a small geographical area (Brain & Grabianowski, 2006, ¶ 2). WiMAX, on the other hand, provides a range of greater distances (WiMAX, 2006, ¶ 2). This includes metropolitan area networks (MANs) and rural areas ("Intel and WiMAX," 2006, ¶ 1). Figure 1.1 provides the maximum distance for the technology available today (Brain & Grabianowski, 2006). WiMAX "can provide both campus-level network connectivity and a wireless last-mile approach that can bring high-speed networking and Internet service directly to customers" (Vaughan-Nichols, 2004, ¶ 3).

Network scale

The smallest-scale network is a personal area network (PAN). A PAN allows devices to communicate with each other over short distances. Bluetooth is the best example of a PAN.

The next step up is a local area network (LAN). A LAN allows devices to share information, but is limited to a fairly small central area, such as a company's headquarters, a coffee shop or your house. Many LANs use WiFi to connect the network wirelessly.

WiMAX is the wireless solution for the next step up in scale, the metropolitan area network (MAN). A MAN allows areas the size of cities to be connected.

Figure 1.1

Now that WiMAX has been briefly touched upon, there must be an understanding as to exactly how WiMAX works. There are two important parts in a WiMAX system: a tower and a receiver (Walton, 2006, ¶ 11). The tower provides coverage up to a distance of 3,000 square miles (Brain & Grabianowski, 2006, ¶ 8). The receiver can be one of several means, "a small box or PCMCIA card, or they could be built into a laptop the way WiFi access is today" (Brain & Grabianowski, 2006, ¶ 8). As depicted in Figure 1.2, there are two methods of wireless service provided by WiMAX: line-of- sight backhaul and non-line-of-sight transmission (Brain & Grabianowski, 2006, ¶ 10). In a line-of-sight backhaul, "a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole" (Brain & Grabianowski, 2006, ¶ 10). Line-of-sight frequencies may range anywhere from 10 GHz to as much as 66 GHz (Brain & Grabianowski, 2006, ¶ 10). In a non-line-of-sight transmission, an antenna connected to the computer connects to the tower thus providing frequencies between 2 GHz and 11 GHz (Brain & Grabianowski, 2006, ¶ 10). Physical obstructions do not interfere with non-line-of-sight service as it does with line-of-sight transmissions but the latter provides less interference and greater bandwidth at a higher frequency (Brain & Grabianowski, 2006, ¶ 10).

Figure 1.2

Next is an explanation of the technology involved with WiMAX. WiMAX is capable of providing broadband wireless access up to 30 miles for fixed stations, and 3 to 10 miles for mobile stations, compared with WiFi, which will only reach up to 300 feet. It can be used just as the WiFi networking, but with a much more efficient bandwidth use that allows WiMAX to transfer data over longer distances ("What is WiMax," n.d., ¶ 1.) It is a possibility that WiMAX coverage could approach up to 30 miles but the average for most WiMAX networks "will likely boast 4-5 mile range (in NLOS capable frequencies) even through tree cover and building walls." ("What is the Range," n.d., ¶ 3.)

WiMAX uses a variety of technology to be operational. First, there is the hardware technology used to function. The following diagram (Figure 1.3), describes the different type of devices that may include network termination units, internal radio modules, network interface cards, PCMCIA cards, external boxes that connect to Ethernet or USB sockets on communication devices ("Introduction to WiMAX," n.d., 2006)

Figure 1.3

One of the main concerns for anybody who manages a wireless network is security. WiMAX uses security protocols that are newer, and supports two quality encryptions standards, that of the DES3 and AES, which is considered leading edge. The data transferred on a WiMAX network needs to be encrypted "using Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) which uses AES for transmission security and data integrity authentication." ("What is the WiMAX Security," 2006, ¶ 3).

When dealing with WiMAX, there are several regulations that take place. According to the Broadband Wireless Exchange Magazine (2006), The Institute of Electrical and Electronics Engineers Standards Association (IEEE-SA) created Standard 802.16, which contains specifications for a Wireless Metropolitan Area Network (WMAN) interface specifically referred to as WiMax. In order to have mass approval