Abstract :
What is a wireless local loop?
In a telephone network, a wireless local loop (WLL)
is a generic term for an access system that uses a wireless link to connect
subscribers to their local exchange in place of conventional copper cable.
Using a wireless link shortens the construction period and also reduces installation and operating costs.
How does WLL work?
WLL, which stands for Wireless Local
Loop is of course a technology that connects subscribers to the PSTN using
radio signals as a substitute for copper for all or part of the connection
between the subscriber and the switch. This includes cordless access systems, proprietary
fixed radio access, and fixed cellular systems. WLL phones in homes, offices or
even boats connect with a wireless system in a manner similar to that of CDMA
cell phones.
The difference is that WLL phones usually
stay in a relatively fixed location. WLL phones often connect to AC current
rather than using batteries. They are used to provide voice, fax, and data
connections. The diagram below shows how the subscriber unit conveys digital signal through RF to the base
station (RBS or BTS), which has a landline to the BSC and then back to the main
switch office. This has in turn its own connection to the PSTN and hence to
other subscribers.
UsingWLL for data transfer applications
rather than using cable or DSL is also becoming a viable option because of the low
setup costs of WLL. Below is a diagram of theWLL used in computer data
transfers. However price per month for subscribers is another matter. In 2001 a
typical contract can run upwards of $100 a month for a 1 Mbps service. This
is ontop of the $1500 connection fee. However if the only other choice is no broadband at all, WLL may
look much more attractive
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