wireless protocol

1. CSC 4315
(WIRELESS NETWORKS AND
PROTOCOLS)
LECTURE 6
Department of Maths and Computer-
Science
Faculty of Natural and Applied Science
BY
DR. BABANGIDA ALBABA
AND
UMAR DANJUMA MAIWADA

2. MOBILE CELLULAR NETWORKS
 A cellular network or mobile network is a communication
network where the last link is wireless. The network is
distributed over land areas called cells, each served by at
least one fixed-location transceiver, but more normally three
cell sites or base transceiver stations.
 A cellular network is a radio network distributed over land
through cells where each cell includes a fixed location
transceiver known as base station. These cells together
provide radio coverage over larger geographical areas. User
equipment (UE), such as mobile phones, is therefore able to
communicate even if the equipment is moving through cells
during transmission.
 Cellular networks give subscribers advanced features over
alternative solutions, including increased capacity, small
battery power usage, a larger geographical coverage area
and reduced interference from other signals. Popular
cellular technologies include the Global System for Mobile
Communication, general packet radio service, 3GSM and
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3. BASIC PRINCIPLES
 The initial idea of mobile telephone systems was to deploy
large towers to cover wide service areas. However the
number of simultaneous users would be severely limited.
 Mobile handsets would also need to generate plenty of power,
hence would be very large and expensive.
 The cellular concept was basically introduced to improve
efficiency of mobile telephony.
 The network is distributed over land areas called cells, each
served by at least one fixed location transceiver, known as a
base transceiver stations (BTS)
 1G refers to the first generation of mobile cellular technology,
which was introduced in the 1980’s based on analog radio
technology.
 The most common 1G standard was the Advanced Mobile
Phone System (AMPS) developed by Bell Labs in the USA.
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5. CELL DESIGN
The two common cell designs used are Square and
Hexagonal Patterns.
 Square Pattern – Antennas within cells of width d
have four neighbors at distance d, and four others
at distance √(2d)
 Hexagonal Pattern - Provides equidistant
antennas but not always precise hexagons due to
topographical limitations
 Hexagonal pattern is preferred by network
operators because if all adjacent antennas are
equidistant it simplifies handoff i.e. discovery of,
and switching to a new BTS that has a stronger
signal.
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7. CHANNEL SHARING
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8. FREQUENCY REUSE
 To increase efficiency of the cellular network,
frequency reuse is a technique that enables
reusing the same frequencies within the n e t w o r
k w i t h o u t causing interference.
 This requires grouping a number of adjacent cells
(N) into groups known as Clusters.
 Cells within the same cluster cannot use the same
frequency. However, cells in a cluster can reuse the
same frequencies used by other clusters.
 By controlling the transmit power of BTS in each
cluster, the same frequency can be used by users
in different clusters. Thus if there are 5 clusters, the
maximum number of simultaneous users would be
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11. CELLULAR NETWORK ARCHITECTURE
 A cellular network is a radio network distributed
over land through cells where each cell includes a
fixed location transceiver known as base station.
These cells together provide radio coverage over
larger geographical areas.
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13. 2G – TIME DIVISION MULTIPLE ACCESS
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18. 2.5G – CODE DIVISION MULTIPLE ACCESS
 Spread spectrum modulation
o originally developed for the military
o resists jamming and many kinds of
interference
o coded modulation hidden from those w/o the
code
 All users share same (large) block of spectrum
o one for one frequency reuse
o soft handoffs possible
 All 3G radio standards based on CDMA
o CDMA2000, W-CDMA and TD-SCDMA 18

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21. 1G, 2G, 3G MULTI-ACCESS TECHNOLOGIES
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3.5G, 4G and future wireless systems optimize a
combination of frequency, time and code multiplexing

22. THE 3G VISION
 Universal global roaming
 Sought 1 standard (not 7), (but got 3:
 3GSM, CDMA 2000 & TD-SCDMA)
 Increased data rates
 Multimedia (voice, data & video)
 Increased capacity (more spectrally efficient)
 Data-centric architecture (ATM at first, later IP)
 But deployment took much longer than expected
 No killer data app; new spectrum costly; telecom bubble
burst; much of the vision was vendor-driven
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vision. : the ability to see : sight or eyesight. : something that you imagine
: a picture that you see in your mind. : something that you see or dream
especially as part of a religious or supernatural experience.

24. 3G RADIO TECHNOLOGY TODAY
• EDGE – GSM evolution, i.e. TDMA
– Legacy; sometimes referred to as 2.75G
• CDMA 2000 – Multi Carrier CDMA
– Evolution of IS-95 CDMA
• UMTS/3GSM (W-CDMA, HSPA) – Direct Spread CDMA
– Defined by 3GPP
• TD-SCDMA – Time Division Synchronous CDMA
– Defined by Chinese Academy of
Telecommunications Technology under the Ministry
of Information Industry
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27. THE EVOLUTION OF MOBILE TECHNOLOGIES
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28. 1G
 1G refers to the first generation of wireless cellular
technology (mobile telecommunications). These are
the analog telecommunications standards that were
introduced in the 1980s and continued until being
replaced by 2G digital telecommunications.
 Note:
 Analog is relating to or using signals or information
represented by a continuously variable physical
quantity such as spatial position, voltage, etc.
 Digital data, discrete data, usually represented
using binary numbers. Digital media, media stored
as digital data. Digital radio, which uses digital
technology to transmit or receive. Digital television,
television systems which broadcast using digital
signals.
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29. 2G
 2G (or 2-G) is short for second-generation cellular
technology. 2G cellular networks were commercially
launched on the GSM standard in Finland by
Radiolinja (now part of Elisa Oyj) in 1991
 2G technologies enabled the various networks to
provide the services such as text messages, picture
messages, and MMS (multimedia messages). All
text messages sent over 2G are digitally encrypted,
allowing the transfer of data in such a way that only
the intended receiver can receive and read it.
 After 2G was launched, the previous mobile
wireless network systems were retroactively
dubbed 1G. While radio signals on 1G networks are
analog, radio signals on 2G networks are digital.
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30. 3G
 3G is the third generation of wireless technologies.
It comes with enhancements over previous wireless
technologies, like high-speed transmission,
advanced multimedia access, and global roaming.
 3G is mostly used with mobile phones and
handsets as a means to connect the phone to the
internet or other IP networks in order to make voice
and video calls, to download and upload data, and
to surf the Web.
 The 3G standard, although it still serves as a
fallback for some cellular providers, has largely
been superseded by the 4G standard, which itself is
being eclipsed by 5G services.
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31. 4G
 4G is the fourth generation of broadband cellular
network technology, succeeding 3G. A 4G system
must provide capabilities defined by ITU in IMT
Advanced. Potential and current applications
include amended mobile web access, IP telephony,
gaming services, high-definition mobile TV, video
conferencing, and 3D television.
 Mobile 4G network uses several frequencies:
 700 MHz (Band 28 - Telstra / Optus) 850 MHz (Band 5 -
Vodafone)
 900 MHz (Band 8 - Telstra) 1800 MHz (Band 3 - Telstra /
Optus /
 Vodafone) 2100 MHz (Band 1 - [a small number of
Telstra sites] /
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32. LTE
 Long-Term Evolution (LTE) is a standard for wireless broadband
communication for mobile devices and data terminals, based on the
GSM/EDGE and UMTS/HSPA technologies. It increases the capacity
and speed using a different radio interface together with core network
improvements.
 Note
 Broadband is wide bandwidth data transmission which transports multiple
signals and traffic types.
 The Global System for Mobile Communications is a standard developed
by the European Telecommunications Standards Institute to describe the
protocols for second-generation digital cellular networks used by mobile
devices such as mobile phones and tablets.
 Enhanced data for global evolution (EDGE) is a high-speed mobile data
standard, intended to enable second-generation global system for mobile
communication (GSM) and time division multiple access (TDMA) networks
to transmit data at up to 384 kilobits per second (Kbps).
 UMTS (Universal Mobile Telecommunications Service) is a third-
generation (3G) broadband, packet-based transmission of text, digitized
voice, video, and multimedia at data rates up to 2 megabits per second
(Mbps).
 HSPA (high speed packet access) is a third-generation (3G) mobile
broadband communications technology. The term HSPA actually refers to
two specific protocols used in tandem, high speed downlink packet access
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33. MOBILE GENERATIONS
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34. QUESTIONS
THANK YOU FOR YOUR ATTENTION !!!
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