bcape311.pdf - JAMIA HAMDARD Introduction to Wireless...

JAMIA HAMDARD
Introduction to Wireless Communication
(BCAPE311)
Assignment-4
Submitted by:
Nabeel Syed Hasan
BCA Section: B
Roll No: 18
Enrollment No. 2019-301-093
Submitted To: Dr. Sapna Jain

Q1 Write short note on the following topics-
a) Bluetooth: It is a Wireless Personal Area Network (WPAN) technology and is
used for exchanging data over smaller distances. Ericson invented this
technology in 1994. It functions at 2.4 GHz to 2.485 GHz in the unlicensed,
commercial, science and medical (ISM) band. The maximum number of
devices which can be connected simultaneously is 7. Bluetooth ranges upto 10
metres. Depending upon the version, it offers data rates of up to 1 Mbps or 3
Mbps. The spreading technique which it uses is FHSS (Frequency hopping
spread spectrum). A bluetooth network is called piconet and a collection of
interconnected piconets is called scatternet.
The various layers in the Bluetooth protocol stack are:
• Radio (RF) layer
• Baseband Link layer
• Link Manager protocol layer
• Logical Link Control and Adaption protocol layer
• SDP layer
• RFCOMM layer (Radio Frequency Communication)
b) AMPS: Advanced Mobile Phone System (AMPS) was a standard for analog
cellular phone system developed by Bell Labs and officially introduced by
AT&T in 1983. The analog service of AMPS has been updated with digital
cellular service by adding to FDMA. This service is known as digital AMPS (D-
AMPS).
Frequency ranges within the 800 and 900 MHz are allocated for cellular
telephones in AMPS. Half of the signal is used for sending signals and half is
used for receiving signals.
In particular, it has a high bandwidth requirement when the number of
conversations is very high. In AMPS the cells are 10 km to 20 km apart from
each other. Since, it was an analog technology, it suffered from noise and
eavesdropping.
c) Cordless Technology: The technology used in this is known as DECT (Digital
Enhanced Cordless Telecommunications) technology. It was developed by the
ETSI (European Telecommunications Standards Institute) in the year 1988.
DECT was first known as Digital European Cordless Telecommunications but its
name was later changed to the current name to reflect global acceptance.
DECT is very energy-efficient and also gives high quality of sound as compared to
previous standards.
It also has high level of security against Interception and also has minimum risk of
radio interference.
d) Reflection: Reflection occurs when an electromagnetic wave falls on an object,
which has very large
dimensions as compared to the wavelength of the propagating wave. A part of it is
transmitted through it when a radio wave falls on another medium with different
electrical properties, while some energy is reflected back. If the medium on which the
EM wave is incident is a dielectric, some energy is reflected back and some energy is
transmitted. If the medium is a perfect conductor, all energy is reflected back to the