Wireless Local Loop

Wi-Fi

Mobile connectivity for computers is a rapidly growing requirement and WiFi has become the de-facto IEEE 802.11 standard with peak operating speeds of around 54 Mbps.
As a result of the flexibility and performance of the system, many Wi-Fi "hotpots" have been set up and more are following. These enable people to use their laptop computers as they wait in hotels, airport lounges, cafes, and many other places using a wireless link rather than needing to use a cable.

Wimax

The IEEE 802.16 Working Group has developed point-to-multipoint broadband wireless access standard for systems in the frequency ranges 10-66 GHz and sub 11 GHz. The standard covers both the Media Access Control (MAC) and the physical (PHY) layers. and is designed to accommodate either Time Division Duplexing (TDD) or Frequency Division Duplexing (FDD) deployments, allowing for both full and half-duplex terminals in the FDD case.
WiMax is an IEEE 802.16 compliant technology for fix broadband wireless access system employing a point to multipoint architecture. It addresses the shortcomings of IEEE 802.16 by specifying the features that are mandatory or optional for deployment of real time systems by different vendors.

DECT

DECT stands for Digital European Cordless Telecommunications (DECT) standard and supports data rate in excess of several hundred Kbps. DECT provides 120 duplex channels through using ten separate carriers multiplexing 12 send and 12 receive channels on each carrier. Because of its ability to support advanced services and universal applicability DECT could also be used for Wireless Local Loop.

MMDS

The MMDS frequencies, located in the 2.1 GHz to 2.7 GHz band, are another option to deliver broadband wireless services. The MMDS frequencies have traditionally been used to provide a one-way, analog wireless cable TV broadcast service.
MMDS is seen as a viable broadband service delivery option for broadband digital data and TV directly into the home.

LMDS

LMDS occupies the largest chunk of spectrum ever devoted to any one service. Located in sections of the 27.5 to 31.3 GHz band, LMDS can consist a bandwidth of up to 1.3 GHz.
LMDS networks can provide two-way broadband services including video, high-speed internet access and telephony services.
A LMDS network can be composed of a series of cells that each deliver point-to-multipoint services to subscribers. Each transmitter in a cell serves a relatively small area, about two to three miles in diameter.

The lack of standards for equipment has been one of the worst problems in terms of ensuring interoperability and keeping costs down. Some vendors promote Time Division Duplexing (TDD) and some promote Frequency Division Duplexing (FDD) scheme for sharing the spectrum. Also, the third generation (3G) wireless system standards is one influence on the development of standards for LMDS.