Multipoint Multichannel Distribution Service
MMDS is a technology for delivering fixed wireless (as opposed to mobile) high-speed acess. There are two blocks reserved for MMDS one in the 2.1GHZ band and one from 2.5-2.7GHZ. Because MMDS operates at higher power levels than un-liscensed rf standards such as 802.11 (contingent on liscensing)range can be as far as 35 miles from a centrally located transmitter with line of sight...
MMDS channels (currently there are 8) were carved out of existing ITFS (microwave television) spectrum allocation of 31 6mhz bands. Bandwidth delivered across a single channel can approach 10Mb/s and different channels are typically used to send and recieve, subchannelization can be performed so that an indidual might recieve as little as 128K
The three largest MMDS liscenses (covering about 80% of the liscensed geographical area) are MCI worldcom, Nucentrix and Sprint.