WiMax: Worldwide Interoperability for Microwave Access
WiMax is a popular name of the 802.16 wireless metropolitan-area network standard, including both 802.16-2004 for fixed WiMAX and 802.16-2005 for mobile WiMAX. WiMax has a range of up to 31 miles. Data rates for WiMax can reach up to 75 Mbps (Fixed) or 15 Mbps (
- 802.16-2004 is often called 802.16d, since that was the working party that developed the standard. It is also frequently referred to as "Fixed WiMAX" since it has no support for mobility.
- 802.16e-2005 is an amendment to 802.16-2004 and is often referred to in shortened form as 802.16e. It introduced support for mobility, amongst other things and is therefore also frequently called "Mobile WiMAX".
The devices that make the Wi-Max network are CPE, OSM, Access points and microwave backhaul. CPE talks to the Access point by using the Wi-max standard. Base station offloads the traffic on the city POP by using the microwave backhaul.
The deployment of the Wi-Max is similar to the Wi-fi. The Wi-Max access point sends signals to the Wi-Max receivers, which is placed at the top of the room at the subscriber’s end. Quality of service (QOS) is some issue with the Wi-Max because when more users gain access to the access points to towers. Wi-Max is an ideal wireless network communication system where is distance is not favorable for the wired networks.
Comparison with Wi-Fi
Comparisons and confusion between WiMAX and Wi-Fi are frequent, possibly because both begin with the same two letters, are based upon IEEE standards beginning with "802.", and both have a connection to wireless connectivity and the Internet. Despite this, the two standards are aimed at different applications.
- WiMAX is a long-range system, covering many kilometers that typically uses licensed spectrum (although it is possible to use 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 (similar to data access via a cellphone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.)
- Wi-Fi is a shorter range system, typically hundreds of meters, 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. Free community wifi networks have shown that with proper antennas, wifi can have very long ranges.
- WiMAX and Wi-Fi have quite different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on setting up connections between the Base Station and the user device. Each connection is based on specific scheduling algorithms, which means that QoS parameters can be guaranteed for each flow. Wi-Fi has introduced a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. This means that QoS is relative between packets/flows, as opposed to guaranteed.
- WiMAX is highly scalable from what are called "Femto"-scale remote stations to multi-sector 'maxi' scale base that handle complex tasks of management and mobile handoff functions and include MIMO-AAS smart antenna subsystems.
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, often 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 customers.