iDEN
iDEN is a mobile telecommunications
technology, developed by Motorola , which provides its users the benefits of a
trunked radio and a cellular telephone . iDEN places more users in a given
spectral space, compared to analog cellular and two-way radio systems, by using
speech compression and time division multiple access TDMA . Notably, iDEN is
designed, and licensed, to operate on individual frequencies that may not be
contiguous. iDEN operates on 25kHz channels, but only occupies 20 kHz in order
to provide interference protection via guard bands. By comparison, TDMA
Cellular ( IS-54 and IS-136 ) is licensed in blocks of 30 kHz channels, but
each emission occupies 40 kHz,and is capable of serving the same number of
subscribers per channel as iDEN.
iDEN supports either three or six interconnect
users (phone users) per channel, and either six or twelve dispatch users
(push-to-talk users) per channel. Since there is no Analogue component of iDEN,
mechanical duplexing in the handset is unnecessary, so Time Domain Duplexing is
used instead, the same way that other digital-only technolgies duplex their
handsets. Also, like other digital-only technologies, hybrid or cavity
duplexing is used at the Base Station ( Cellsite ).
More Than a Wireless Phone iDEN technology offers you more than just a wireless phone. It's a Motorola
complete communications system that you hold in your hand. Combining
speakerphone, voice command, phone book, voice mail, digital two-way radio,
mobile Internet and e-mail, wireless modems, voice activation, and voice
recordings so that you can virtually recreate your office on the road.
You can download iDEN seminar abstract from here.
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