1. WIRELESS LOCAL LOOP
SUMBITTED BY:
MUKESH KUMAR
M.TECH(2010ECB1026)

2. INTRODUCTION
 In the telephone networks, the circuit between the
subscriber's equipment (e.g. telephone set) and the
local exchange is called the subscriber loop or local
loop.
 Copper wire has been used as the medium for local
loop to provide voice and voice-band data services.
 Since 1980s, the demand for communications services
has increased explosively. There has been a great need
for the basic telephone service, i.e. the plain old
telephone service (POTS) in developing countries.

3. Cont..
 Wireless local loop provides two-ways a telephone
system…………..
 Wireless local loop includes cordless access
system, proprietary fixed radio access system and
fixed cellular system. It is also known as fixed radio
wireless. This can be in an office or home.
 Broadband Wireless Access (BWA), Radio In The
Loop (RITL), Fixed-Radio Access (FRA) and Fixed
Wireless Access (FWA).

4. COMMUNICATION FOR WLL
 Point-to-Point.
 Microwave platform
 Fixed wireless communication does not require
feeds from satellite or from the local phone service.
This reduces the cost and time for planning miles
of cable.

5. FIXED SUBSCRIBER UNIT
 Interface
 Perform channel coding/decoding, mod./demod.,
transmission /reception of signal
 In some types of commercial products, an FSU is
integrated with handset.
 The basic functions of this integrated FSU are very
similar to those of the handset for mobile
communications, except that it does not have a rich set
of functions for mobility management. Another
example of FSU implementation is a high-capacity,
centralized FSU serving more than subscriber.

7. BASE SATATION SWITCHING
CENTRE
 BSC controls one or more BTSs and provides an
interface to the local exchange (switch) in the central
office.
 Transcode between the source codes used in wired
network and that at the air interface.
 BSC is also called the radio port control unit (RPCU)
or the transcoding and network interface unit (TNU).

8. ARCHITECTURE

9. TECHNICAL REQUIREMENTS
 Communications Quality
 Short Construction Period
 Low Cost
 Absence Of Interference With Other Wireless
Systems: microwave & broadcasting system
 High Traffic Volume

10. IMPLEMENTATION OF WLL
 Analog Cellular
 Digital Cellular
 Personal Communication Service (PSN)
 Cordless Telephone

11. ANALOG CELLULAR
 Advanced mobile phone system (AMPS), Total
Access communications systems (TACS), Nordic
mobile telephone (NMT)
 Due to widespread deployment, analog cellular
systems are expected to be a major wireless
platform for WLL.

12. DIGITAL CELLULAR
 Rapid growth
 GSM,TDM,E-TDM, CDMA
 71%..........

13. PERSONAL COMMUNICATION
SERVICE
 PCS/PCN incorporates elements of digital cellular
and cordless standards as well as newly developed
radio-frequency (RF) protocols. Its purpose is to
offer low-mobility wireless service using low-
power antennas and lightweight, inexpensive
handsets. PCN is primarily seen as a city
communications system with far less range than
cellular.

14. WLL VS. WIRELINE SYSTEM
 Concentration of Resources
 Flexibility to planning and deployment of the system
 Fast network deployment and change
 Lower maintenance and capital costs
 Local mobile feature
 Temporary Installation

15. ADVANTAGES
 Fast Development
 Low Construction Cost
 Low Operation And Maintenance Cost
 Costumer Connection Cost
 High Bandwidth Services Provision
 Lower Network Extension Costs
 High System Capacity

16. CASE STUDY
 there is a community with 550 existing subscribers, of which 150 are on 2-
or 4-party line service, and the telephone company is holding some 50
orders for lines which it cannot fulfill including a small number of ISDN
connections. These ISDN connections cannot be served by the existing
cable pairs, either because special conditioning is required or the
subscriber is more than two miles from the remote switch unit (which is
served by an under-utilized 150 Mb/s fiber feeder). The estimated cost to
convert the party lines to exclusive service exceeds $3000 per
subscriber, and this investment would do nothing to help improve the held
order, ISDN or limited CATV and Cellular coverage in the area.
 Nortel believes that deployment of a Wireline Equivalent FWA system
would provide significant relief. Under the FWA service proposed by
Nortel, the telephone company would install or use a shared radio tower
and site at the end of the fiber feeder, and immediately resolve the party
line, unserved and ISDN situations at an installed cost of less than $1000
per subscriber excluding the incremental tower and site costs which would
be a one-time subsidy.

17. CONCULSION
 High capacity for voice channels and quick
start of services.
 WLL will play a more important role for local
loop services in future.

18. THANKS