Broadband wireless access - summary
Communication services will be combined in many different ways to offer high speed digital data to industry, office and residential users. Desktop computers, television sets, notebooks and handheld terminals will turn into multifunctional devices for internet and e-mail access, VPN connectivity, instant messaging, video conferencing, media streaming, interactive gaming, VoIP, E-Commerce, telemetry, remote biometric analysis and many more applications.
Developed countries usually have a fairly good wireline Metro Area infrastructure. Fibre based networks provide E1/T1 access for industrial and office environments. CATV and plain old telephone lines provide last mile broadband DSL access for residential users, and fibre to the home is currently being heavily promoted in some countries.
Still there is a demand for wireless broadband access in remote and urban areas. The key driver for this is mobility along with the expectation of the end users to have broadband data available at their finger tips wherever they are roaming. On top of mobile services, fixed wireless is an attractive alternative to delivering competitive broadband data to underserved areas in emerging and developed markets. Thanks to its nature, it is straightforward to deploy and does not involve the prohibitive costs of laying cable networks.
Today three major technologies for broadband wireless access can be identified:
Wi-Fi networks (the brand name for WLAN) are focussed on public hot spots, offices and the industrial environment. City-wide meshed networks will play an important role in municipal applications for both public authorities and private users.
Wi-Fi has experienced fast but unorganised growth and is mostly a rather patchy solution. Roaming is possible within single Wi-Fi networks but is not supported on a general scale. Nevertheless, WLAN networks have gained wide acceptance and proven to be an efficient solution for short distance wireless coverage. Wi-Fi will also be a versatile option to divert WiMAX and 3G services into picocell areas.
Due to the unlicensed spectrum utilised, Wi-Fi may suffer from RF-interference of co-located systems operating in the same ISM band. Moreover, limitations exist with regard to QoS. However, if Wi-Fi deployment is well co-ordinated, disturbances can be reduced to a minimum.
WiMAX (Worldwide Interoperability for Microwave Access”) and future 3G systems will be the real next quantum leap to deliver wireless broadband for business, SoHo (Small office Home office) and residential users.
WiMAX aims to provide broadband last mile access for fixed (IEEE 802.16-2004) as well as mobile (802.16e-2005) wireless services and long range point to point RF and millimetre wave backhauling. It addresses the consumer, office and industry markets. WiMAX networks will be operating in licensed frequency bands to ensure high speed access at an appropriate QoS. Similar to the Wi-Fi Alliance, the industry has founded the WiMAX Forum, a non-profit organisation which promotes WiMAX and certifies interoperability of WiMAX products and network components in accordance with IEEE 802.16 and ETSI HiperMAN wireless MAN standards. Standardisation and interoperability are key to the success of WiMAX as this will ensure a competitive environment and drive down equipment costs through integration and economies of scale in mass production.
Possibly, WiMAX 802.16 will become a member of the IMT-2000 family besides the existing 3G technologies. This would allow WiMAX to have the same access to spectrum as todays pure” 3G networks and would support WiMAX as an alternative wireless technolgy besides 3G.
3G systems are already being rolled out on a larger scale and will offer initial medium speed data. A migration path for 3G evolution towards real broadband data is already being defined, and one can expect Wi-Fi, WiMAX and 3G systems to complement each other, finally converging into a 4G world.
