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division of transmission medium into different channels so that transmission from different
stations is separated from each other. It employs spread spectrum digital technology where the
data is fragmented into small chunks over a number of different frequencies available for use.
Analog to digital conversion takes place where audio input is first digitized into binary elements.
The CDMA system works directly on 64 kbit/sec digital signals.

CTM: CDMA is a digital cellular technology that uses spread spectrum technique where the entire bandwidth
is divided among several users for transmission of data.

8.14.3 GPRS (General Packet Radio Services)

GPRS or General Packet Radio Services provides various features over 2G phones with respect to
high speed data transfer. A user can send and receive data at the same time and thus uses the same
bandwidth for both purposes. Using GPRS technology, a user can make a call and at the same time
receive a message without disconnecting the call. However, GPRS usage is charged for the amount
of data sent or received. GPRS can provide data rates up to 32kbps to 48kbps. With this data rate,
email messages, video streaming, audio files, etc., can be downloaded and, therefore, can be called
2.5G technology as it lies between the second (2G) and third (3G) generations of mobile telephony.
Services Provided By GPRS

(a) Sending and receiving text messages.

(b) Internet access.
(c) Multimedia Messaging Service (MMS).

(d) Internet applications for smart devices through Wireless Application Protocol (WAP).

(e) Networking facility with one person or with several persons in a group, i.e., videoconferencing.
CTM: GPRS provides high speed data transfer. A user is allowed to download video streaming, audio files,
email messages, etc.

8.14.4 Wireless in Local Loop (WLL)

WLL provides the subscribers with wireless phone facility to communicate with each other in order
to get better voice quality. It employs the use of electromagnetic radiation to connect subscribers
to the local exchange without the use of wires. The user can use wireless phone, speaker phone
and parallel phones for communication with each other. In traditional telephone networks, phone
would be connected to the nearest exchange through a pair of copper wires. But in Wireless Local
Loop (wireless in local loop) technology, the subscriber is connected to the nearest exchange
through a radio link instead of copper wires. Wireless in local loop is cheaper and quicker than
copper wire connectivity. As the cost of copper along with the cost of digging increases over time,
this method proves cheaper than using copper wires. It is used in remote areas where digging for
copper wires is not possible.
Computer Networks
There are various technologies like Frequency Division Multiple Access (FDMA), Time Division
Multiple Access (TDMA) and Code Division Multiple Access (CDMA) used for wireless in local loop.
In crowded urban localities where permission to dig may be almost impossible to get, wireless
technology is advised. However, there are also some disadvantages of using wireless in local loop.
First, as the distance between a receiver and transmitter increases in a wireless system, the strength

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