Local Multipoint Distribution Service
From Wikipedia, the free encyclopedia
LMDS is a broadband wireless access technology governed by the IEEE and is outlined by the 802 LAN/MAN Standards Committee through the efforts of the IEEE 802.16.1 Task Group[1].
LMDS commonly operates on microwave frequencies across the 26 GHz and 29 GHz bands. In the United States, frequencies from 31.0 through 31.3 GHz are also considered LMDS frequencies.
LMDS was conceived as a broadband, fixed wireless, point-to-multipoint technology for utilization in the last mile.
Throughput capacity and reliable distance of the link depends on common radio link constraints and the modulation method used - either phase-shift keying or amplitude modulation. In general deployment links of up to 5 miles (8 km) from the base station are possible, but distance is typically limited to about 1.5 miles (2.4 km) due to rain fade attenuation constraints.
Some point-to-point systems also use the LMDS frequencies and can reach slightly farther distances due to increased antenna gain.
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[edit] LMDS History and Outlook
[edit] United States
LMDS showed great promise in the late 1990s. It became known as "wireless cable" for its potential to enable competition with the cable television companies for broadband video to the home. The Federal Communications Commission auctioned spectrum for LMDS in 1998 and 1999.
Despite its early potential and the hype that surrounded the technology, LMDS was slow to find commercial traction. This is mostly attributable to the telecommunications and technology bubble bursting at the time when LMDS was maturing as a concept and LMDS hardware was just starting to come to market. Many equipment vendors simply abandoned their LMDS product portfolios. LMDS is currently in commercial deployment with Nextlink Wireless in the United States.
Many industry watchers believe that the window for LMDS has closed, with the technology having been superseded by several market forces and technologies. Most homes are already reached by at least one broadband technology -- generally either DSL or cable internet. Major telecommunications companies (notably Verizon Communications) have been aggressive about deploying technologies such as IPTV and fiber to the premises. Moreover, LMDS has been surpassed in both technology and commercial potential by the new WiMax standard. (Sprint Nextel has announced a major commitment to WiMax.)
[edit] Europe & Worldwide
Although there are some companies (like Telefonica) that use LMDS for providing access services to demanding corporate customers, in the most cases the operators use LMDS for high capacity backhaul for interconnection of other types of networks like GSM, UMTS, WiMAX and Wi-Fi.
[edit] Makers
Out of Production:
Defunct:
- Netro: AirStar
- Ensemble Communications
- Vyyö: Wireless Hub V3000
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[edit] References
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