As DSL and cable modems began to be deployed, wireless systems had to evolve to support much higher speeds to be competitive. Systems began to be developed for higher frequencies, such as the 2.5GHz and 3.5GHz bands.
Very high speed systems, called local multipoint distribution systems (LMDS), supporting up to several hundreds of megabits per second, were also developed in millimeter wave frequency bands, such as the 24GHz and 39GHz bands. LMDSbased services were targeted at business users and in the late 1990s enjoyed rapid but short-lived success.
Problems obtaining access to rooftops for installing antennas, coupled with its shorterrange capabilities, squashed its growth.
The first generations of these fixed broadband wireless solutions were deployed using the same towers that served wireless cable subscribers.
These towers were typically several hundred feet tall and enabled LOS coverage to distances up to 35 miles, using high-power transmitters. First-generation MMDS systems required that subscribers install at their premises outdoor antennas high enough and pointed toward the tower for a clear LOS transmission path.
Sprint and MCI launched two-way wireless broadband services using first-generation MMDS systems in a few markets in early 2000. The outdoor antenna and LOS requirements proved to be significant impediments. Besides, since a fairly large area was being served by a single tower, the capacity of these systems was fairly limited. Similar first-generation LOS systems were deployed internationally in the 3.5GHz band.