Wimax

Abstract

WiMAX is a standards-based technology enabling the deliverance of wireless broadband access as an alternative to cable and DSL. WiMAX provides set, roaming, transportable, and mobile wireless broadband connectivity without the need for direct line-of-sight with a base station. The Institute of Electrical and Electronics Engineers (IEEE) website, the WiMAX Forum website and other internet resources were used to gather information for the paper. The paper describes aspects of the technology, future trends, regulatory issues, and global implications surrounding WiMAX. A list of companies and their involvement with WiMAX is also provided.

WiMAX

WiMAX is a standards-based technology enabling the deliverance of wireless broadband access as an alternative to cable and DSL. WiMAX provides set, roaming, transportable, and mobile wireless broadband connectivity without the need for direct line-of-sight with a base station.

WiMax is an interoperability standard for broadband wireless communication. The technical design portion of the standard defines Media Access Control, and the Physical layer. The Media Access Control (MAC) portion of the standard describes the use of scheduling to make sure that each client is allocated a time slot with the base station. The MAC also describes the use of QoS (Quality of Service) and authentication. The physical layer portion of the standard describes a frequency spectrum from 2 GHz to 66 GHz. The 2 GHz to 11 GHz is intended for non-line of sight usage, and the 10 GHz - 66 GHz range is intended for line of site usage. The physical layer portion of the standard also describes the methods used to communicate with the base stations. Time-Division Multiplexing (TDM) is used by the base station to communicate with the clients, and Time-Division Multiple Access (TDMA) is used to communicate back to the base stations. The standard also supports Time-Division Duplexing (TDD) and Frequency-Division Duplexing (FDD) for burst transmissions.

To access the internet these days you have three choices. First there is broadband access, which includes Cable modem, DSL or a T1 line in the office. Then there is Wi-Fi access, which comes from a wireless router, Wi-Fi hot spots can be found in airports, hotels, coffee shops and libraries. Finally dial-up access which is very slow and not very reliable. For many people still using dial-up it is because broadband is not available in their area and this is where Worldwide interoperability Microwave Access (WiMAX IEEE 802.16) comes in. WiMAX is an acronym that stands for Worldwide Interoperability for Microwave Access, a certification mark for products that pass conformity and interoperability tests for the IEEE 802.16 standard. WiMAX is a standards-based wireless technology that provides high-throughput broadband connections over long distances. WiMAX can be used for a number of applications, including "last mile" broadband connections, hotspots and cellular backhaul, and high-speed enterprise connectivity for business. Products that pass the conformity tests for WiMAX are capable of forming wireless connections between them to permit the carrying of internet packet data. It is similar to WiFi in concept, but has a number of enhancements designed to improve performance and permit usage over much greater distances. It provide high speeds like broadband wireless access to avoid the expense of running wires, and coverage like a cell phone rather the that of Wi-Fi which are limiter to hot spots. WiMAX has the potential to do for broadband Internet access what cell phones have done to phone access. WiMAX is similar to Wi-Fi but a higher speeds and over greater distances and able to service more people. One major potential for WiMAX to reach into suburban area that does not have access to broadband through cable of DSL. WiMAX is similar to cell technologies; one WiMAX tower can cover a very large area as much as 3,000sq miles. A WiMAX tower uses two methods to communicate with your computer. One is a non-lone of sight where a small antenna in your computer connects to the tower similar to Wi-Fi hotspots. This method uses a low frequency able to go through walls and around corners. The Wi-Fi style will service an area similar to a cell phone coverage area of about 25 miles. The second method uses Line of sight antennas on the roof of your building to pick up the WiMAX signal. This uses a higher frequency to provide greater bandwidth at these higher frequencies there are less interference. Right now Wi-Fi will reach speeds of 54 Mbps but WiMAX will achieve speeds up to 70 Mbps, this will provide cable type speeds for several hundred users.

Many companies are part of the WiMAX forum. Their roster is made up of about 370 companies of all types and sizes. The roster is broken into three distinct groups of "Regular" members, "Principal" members, and "Board" members.

Worldwide Interoperability for Microwave Access or the Air Interface Standard (WiMAX) is one of today's newest technologies that have taking the world and the wireless community by storm. WiMAX is a broadband wireless technology that seems to work well with Voice over Internet Protocol (VOIP); however this is not WiMAX's only purpose or means of existence. WiMAX is designated as 802.16 by the Institute of Electrical and Electronics Engineers (IEEE) and is considered to be a broadband wireless technology (BWA) which can and is used to create wireless metropolitan area networks (MAN). WiMAX appears to be revolutionizing the world in terms of bringing broadband wireless technology to the world, thus making possible the implementation and development of this technology globally.

WiMAX technology will bring with it many global implications. One of those implications is the possible addition of broadcast towers to riddle the landscape. Another issue is the possible long term health effects of WiMAX's microwave frequencies on the people of the world.

WiMAX is a point-to-multipoint topology that made up of single base stations that communicate with multiple subscriber stations. The WiMAX specification describes both the Media Access Control (MAC) sublayer and the Physical layer.

Media Access Control is a sublayer of the OSI model Data Link Layer. It is between the Logical Link sublayer and acts as an interface to the Physical layer ("Media Access Control", 2006). The MAC protocol of WiMAX is designed for high bit rate uplink and downlink data transfer. WiMAX is designed to support many types of services simultaneously with continuous and burst frame transmissions using time division multiplexing. The MAC protocol defines among other things, the Quality of Service (QoS), bandwidth allocation, data transport and a privacy sublayer. The MAC