Wireless access evolution

Wireless Access Evolution
BY
Subscribers
AJAL.A.J
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Voice Broadband

Mobile wireless evolution:

Introduction to Mobile wireless evolution:
By AJAL.A.J

Before going 2 start with wireless
evolution ,
Lets review

3

Classes of transmission media

7.4

GUIDED MEDIA
Guided media, which are those that provide a conduit
from one device to another, include twisted-pair cable,
coaxial cable, and fiber-optic cable.

Topics discussed in this section:
Twisted-Pair Cable
Coaxial Cable
Fiber-Optic Cable

Types
(1) shielded twisted-pair (STP)
Figure UTP and STP cables (2) unshielded twisted-pair (UTP).

Twisted pair Connectors

RJ45 connectors

Outer conductor shields the inner conductor from
picking up stray signal from the air.

For frequencies ranging from100KHz to 500MHz

Coaxial cable connectors

BNC Connectors - Bayone-Neill-Concelman

Types of Connectors

1) BNC connector - to connect to a TV

2) BNC T connector - in ethernet networks

3) BNC terminator - used in end of the cable to

prevent the reflection of the signal.

Twisted-Pair Use metallic conductors that accept
and transport signals in the form of
electric current.
Coaxial cable

Optical Fiber Cable that accepts and transports
signals in the form of light.

UNGUIDED MEDIA: WIRELESS
Unguided media transport electromagnetic waves
without using a physical conductor. This type of
communication is often referred to as wireless
communication.

Topics discussed in this section:
Radio Waves
Microwaves
Infrared

Electromagnetic spectrum for wireless communication

Figure Wireless transmission waves

Note

Radio waves are used for multicast
communications, such as radio and
television, and paging systems. They can
penetrate through walls.
Highly regulated. Use omni directional
antennas

Figure Omnidirectional antenna

Note

Microwaves are used for unicast
communication such as cellular telephones,
satellite networks, and wireless LANs.
Higher frequency ranges cannot penetrate
walls.
Use directional antennas - point to point line
of sight communications.

7.27

Figure Unidirectional antennas

Note

Infrared signals can be used for short-range
communication in a closed area using line-of-
sight propagation.

Wireless Channels
 Are subject to a lot more errors than guided
media channels.
 Interference is one cause for errors, can be
circumvented with high SNR.
 The higher the SNR the less capacity is
available for transmission due to the
broadcast nature of the channel.
 Channel also subject to fading and no
coverage holes.

ANY QUESTIONS ? ?
?
Else , we can start with
Mobile wireless evolution:

Introduction to wireless Communications Systems

• In 1897, Guglielmo Marconi first demonstrated radio’s
ability to provide continuous contact with ships sailing the
English channel.

• During the past 10 years, fueled by
* Digital and RF circuit fabrication improvements
* New VLSI technologies
* Other miniaturization technologies
(e.g., passive components)
The mobile communications industry has grown by orders of
magnitude.
• The trends will continue at an even greater pace during the
next decade.

Evolution of Mobile Radio Communications

Mobile Radiotelephone in the U.S.

• In 1934, AM mobile communication systems for municipal
police radio systems.
* vehicle ignition noise was a major problem.
• In 1946, FM mobile communications for the first public
mobile telephone service
* Each system used a single, high-powered transmitter and large
tower to cover distances of over 50 km.
* Used 120 kHz of RF bandwidth in a half-duplex mode. (push-to-
talk release-to-listen systems.)
* Large RF bandwidth was largely due to the technology difficulty
(in mass-producing tight RF filter and low-noise, front-end
receiver amplifiers.)
• In 1950, the channel bandwidth was cut in half to 60kHZ
due to improved technology.

• By the mid 1960s, the channel bandwidth again was cut to
30 kHZ.

• Thus, from WWII to the mid 1960s, the spectrum
efficiency was improved only a factor of 4 due to the
technology advancements.

• Also in 1950s and 1960s, automatic channel truncking was
introduced in IMTS(Improved Mobile Telephone Service.)

* offering full duplex, auto-dial, auto-trunking
* became saturated quickly
* By 1976, has only twelve channels and could only serve 543
customers in New York City of 10 millions populations.

• Cellular radiotelephone

* Developed in 1960s by Bell Lab and others
* The basic idea is to reuse the channel frequency at a sufficient
distance to increase the spectrum efficiency.
* But the technology was not available to implement until the late
1970s. (mainly the microprocessor and DSP technologies.)

• In 1983, AMPS (Advanced Mobile Phone System, IS-41)
deployed by Ameritech in Chicago.

* 40 MHz spectrum in 800 MHz band
* 666 channels (+ 166 channels),
* Each duplex channel occupies > 60 kHz (30+30) FDMA to
maximize capacity.
* Two cellular providers in each market.

• In late 1991, U.S. Digital Cellular (USDC, IS-54) was
introduced.

* to replace AMPS analog channels
π
* 3 times of capacity due to the use of digital modulation
4

( DQPSK), speech coding, and TDMA technologies.
* could further increase up to 6 times of capacity given the
advancements of DSP and speech coding technologies.

• In mid 1990s, Code Division Multiple Access (CDMA,
IS-95) was introduced by Qualcomm.

* based on spread spectrum technology.
* supports 6-20 times of users in 1.25 MHz shared by all the
channels.
* each associated with a unique code sequence.
* operate at much smaller SNR.(FdB)

Mobile Radio Systems Around the World

Examples of Mobile Radio Systems

First Generation (1G)
 1G (First Generation Wireless Technology). Is
the analog, voice-only cellular telephone
standard, developed in the 1980s. It was
invented by Martin Cooper of Motorola Corp
in 1973.
 Before 1G technology was the mobile radio
telephone or 0G (Zeroth G)
 1G phones have been cloned

1. Early Cell System
 Non-trunk radio system
 Does not use multiplexing scheme
 Each radio channel is fixed to a specific user or a
group of users
 Trunk radio system
 (synchronous or asynchronous) multiplexing scheme
 Channels are shared and available to all users
 Advantage: increased efficiency of spectrum usage
 Disadvantage: more complex architecture required

1. Early Cell System
 Trunk radio system (AMPS)
 BTS (base station): controls the air interface
between the mobile station and MTSO
 Mobile station: having frequency-agile machine
that allows to change to a particular frequency
designated for its use by the MTSO
 MTSO: responsible for switching the calls to the
cells providing
 Interfacing with telephone network and backup
 Monitoring traffic
 Performing testing and diagnostics, network

Differences Between First and
Second Generation Systems
 Digital traffic channels – first-generation systems are
almost purely analog; second-generation systems are
digital
 Encryption – all second generation systems provide
encryption to prevent eavesdropping
 Error detection and correction – second-generation
digital traffic allows for detection and correction,
giving clear voice reception
 Channel access – second-generation systems allow
channels to be dynamically shared by a number of
users

First Generation
 What we will look at
 1st Generation technology
 Analogue signals
 Frequency Division
 Handover
 Infrastructure

First Generation
 Early Wireless
communications
 Signal fires
 Morse Code
 Radio

Radio Transmitter 1928 Dorchester

First Generation
 1st Generation devices
 Introduced in the UK by Vodafone
 January 1985
 UK Technology (and Italy)
 Total Access Cellular System (TACS)
 This was based on the American design of AMPS
 Used the 900MHz frequency range
 Europe
 Germany adopted C-net
 France adopted Nordic Mobile Telephone (NMT)

First Generation
 Operates
 Frequency Division Multiple Access (FDMA)
 Covered in next slide

 Operates in the 900MHz frequency range
 Three parts to the communications
 Voice channels
 Paging Channels
 Control Channels

PCS – 1G to 2G technology
 FDMA
 Breaks up the available frequency into 30 KHz channels
 Allocates a single channel to each phone call

 The channel is agreed with the Base station before transmission
takes place on agreed and reserved channel
 The device can then transmit on this channel
 No other device can share this channel even if the person is not talking
at the time!
 A different channel is required to receive
 The voice/sound is transmitted as analogue data, which means
that a large than required channel has to be allocated.

 FDMA
Frequency

 FDMA
 You use this technology all of the time!
 Consider your radio in the house

 As you want different information you change the frequency
which you are receiving

 Voice calls
 Are transferred using Frequency modulation
 The rate at which the carrier wave undulates is changed
 Encoding information

 More resistant to interference than AM radio

(www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0030280.html, 2004)

 1G infrastructure

PSTN

Mobile Switching Centre

First Generation
 Infrastructure
 Base Station
 Carries out the actual radio communications with the
device
 Sends out paging and control signals
 MSC
 Takes responsibility
 Controls all calls attached to this device
 Maintains billing information
 Switches calls (Handover)

First Generation
 Cellular Architecture
 Allows the area to be broken into smaller cells
 The mobile device then connects to the closest
cell
Cell
Cell Cell
Cell Cell Cell
Cell Cell Cell Cell
Cell Cell Cell
Cell Cell
Cell

First Generation
 Cellular Architecture continued
 Cellular architecture requires the available frequency to be
distributed between the cells
 If 2 cells next to each other used the same frequency each
would interfere with each other

Cell
Cell Cell Cell Frequency 900
Cell

First Generation
 There must be a distance between adjoining cells
 This distance allows communications to take place

Cell Frequency 900

Cell Frequency 920
Cell
Cell Cell Cell Frequency 940
Cell

Cell Frequency 960

First Generation
 This is referred to as the “Minimum Frequency Reuse Factor”
 This requires proper planning and can be an issue for all radio
based wireless communications
 Planning the radio cell and how far a signal may go

Cell
Cell Cell
Cell

First Generation
 Radio Planning
 Logically we picture a cell as being a
Octagon
 In reality the shape of a transmission will
change depending on the environment
 In this diagram of a cell you can see this
 The building are the rectangles in dark green
 The darker the shade of green the stronger
the signal

Cell Cell
Cell Cell
Cell

First Generation
 Radio Planning
 Planning needs careful thought
 You must cover the entire area with the minimum of base
stations
 Base stations cost the company money

 They also make the potential for radio problems greater

 Simulations can be used but accurate models of the area is
required
 Best solution is to measure the signals at various points
 From this a decision can be made
Cell
Cell Cell
Cell

First Generation
 Cellular infrastructure why ??
 Cells with different frequencies allow devices to
move between these cells
 The device just informing what frequency they are
communicating at
 Cellular communications can only travel a certain
distance
 Discussed in the wireless LAN’s lecture
 Cell sizes are flexible
 Examples in the TUK TACS system were up to 50 Miles!

First Generation
 Cellular infrastructure
 Once you get to the ‘edge’ of a cell you will need
a handover
 Handover allows the user to move between cells
 After a certain distance the amount of data which is sent in
error becomes greater than the data sent correctly at this
point you need to connect to a new cell which is closer.
 TACS carries this out by monitoring the amplitude of the
voice signal

First Generation
 Communicating with BS1
 Moving towards BS2

Tnm
rasis
snS
ioB2

SBosm
n i nT
is s
ar
1

BS1
BS2

First Generation
 Power of signal now weakening

BS1
BS2

First Generation
 Paging signal stronger so hand over to new MSC

BS1
BS2

First Generation
 Handover
 Once a handover is decided upon by the BS
 The MSC is informed
 All BS in the area of the current location are informed to
start paging the device
 The BS with the strongest signal is then handed over to
 The call can continue
 In reality a lot of calls were dropped whilst waiting for a
handover to take place
 Ending a call
 A 8Khz tone is sent for 1.8 seconds
 The phone then returns to an idle state

First Generation
 TACS
 Problems
 Roaming was not applicable outside of the UK
 All of Europe was using different standards
 Different frequencies
 Different frequency spacing
 Different encoding technologies
 Security
 Calls were easily ‘listened’ upon
 Limited capacity of the available spectrum
 Analogue signal meant a larger than required amount of the
frequency had to be allocated to each call
 Expansion of the network was difficult
 This was unacceptable
 GSM was introduced
 Next weeks lecture!

First Generation
 Summary
 1G systems
 TACS
 Frequency Use
 Infrastructure
 Handover
 Problems

Cellular standards
• Analog cellular: G1 cellular systems
– AMPS: AT&T and Motorola; rapidly giving
way to digital technology worldwide.
– N-AMPS: narrow-band AMPS; Motorola.
– NMT (Nordic mobile telephone) in scandinavia
– TACS (Total access communication system)
developed in England.

TDMA Design Considerations
 Number of logical channels per physical channel
(number of time slots in TDMA frame): 8
 Maximum cell radius (R): 35 km
 Frequency: region around 900 MHz
 Maximum vehicle speed (Vm):250 km/hr
 Maximum coding delay: approx. 20 ms
 Maximum delay spread (∆m): 10 µs
 Bandwidth: Not to exceed 200 kHz (25 kHz per
channel)

Cellular standards continued
• Digital cellular: G2 cellular systems
– GSM (Global System for Mobile communication):
dominates worldwide; adopted in 1987 for pan-Europe
systems; operates in the 800 and 900 MHz ranges and
is ISDN compatible; 4-cell reuse plan and each cell is
divided into 12 sectors; used CDMA; supporting
roaming from country to country.
– D-AMPS (Digital AMPS): AKA US TDMA is the N.
Am. Standard; operates in the same 800 MHz band as
AMPS and uses the same 30 kHz bands as AMPS;
3:1improvement on band utilization over AMPS; co-
exists with AMPS; data rate up to 28.8 bps.
• Others: PDC (Japanese Digital Cellular),
PCS (Personal digital system).

Cellular Communications

• Mobile telephone service - a system for providing
telephone services to multiple, mobile receivers using two-
way radio communication over a limited number of
frequencies.
• Mobile wireless evolution:
– First generation
– Second generation
– Third generation

Evolution of Mobile Radio
Communications
• Major Mobile Radio Systems
– 1934 - Police Radio uses conventional AM mobile communication
system.
– 1935 - Edwin Armstrong demonstrate FM
– 1946 - First public mobile telephone service - push-to-talk
– 1960 - Improved Mobile Telephone Service, IMTS - full duplex
– 1960 - Bell Lab introduce the concept of Cellular mobile system
– 1968 - AT&T propose the concept of Cellular mobile system to FCC.
– 1976 - Bell Mobile Phone service, poor service due to call blocking
– 1983 - Advanced Mobile Phone System (AMPS), FDMA, FM
– 1991 - Global System for Mobile (GSM), TDMA, GMSK
– 1991 - U.S. Digital Cellular (USDC) IS-54, TDMA, DQPSK
– 1993 - IS-95, CDMA, QPSK, BPSK

Example of Mobile Radio Systems

• Examples
– Cordless phone
– Remote controller
– Hand-held walkie-talkies
– Pagers
– Cellular telephone
– Wireless LAN
• Mobile - any radio terminal that could be moves during operation
• Portable - hand-held and used at walking speed
• Subscriber - mobile or portable user

• Classification of mobile radio transmission system
– Simplex: communication in only one direction
– Half-duplex: same radio channel for both transmission and reception
(push-to-talk)
– Full-duplex: simultaneous radio transmission and reception (FDD,
TDD)
• Frequency division duplexing uses two radio channel
– Forward channel: base station to mobile user
– Reverse channel: mobile user to base station
• Time division duplexing shares a single radio channel in time.

Forward Channel

Reverse Channel

Paging Systems
• Conventional paging system send brief messages to a subscriber
• Modern paging system: news headline, stock quotations, faxes, etc.
• Simultaneously broadcast paging message from each base station
(simulcasting)
• Large transmission power to cover wide area.

Cordless Telephone System
• Cordless telephone systems are full duplex communication
systems.
• First generation cordless phone
– in-home use
– communication to dedicated base unit
– few tens of meters
• Second generation cordless phone
– outdoor
– combine with paging system
– few hundred meters per station

Cellular Telephone Systems
• Provide connection to the PSTN for any user location within the radio
range of the system.
• Characteristic
– Large number of users , - Large Geographic area
– Limited frequency spectrum , - Reuse of the radio frequency by the concept
of “cell’’.
• Basic cellular system: mobile stations, base stations, and mobile
switching center.

• Communication between the base station and mobiles is defined
by the standard common air interface (CAI)

– forward voice channel (FVC): voice transmission from base
station to mobile
– reverse voice channel (RVC): voice transmission from mobile
to base station
– forward control channels (FCC): initiating mobile call from
base station to mobile
– reverse control channel (RCC): initiating mobile call from
mobile to base station

Cellular Call Completion

• Components of a signal:
– Mobile Identification Number (MIN) - an enclosed
representation of the mobile telephone’s 10-digit
telephone number.
– Electronic Serial Number (ESN) - a fixed number
assigned to the telephone by the manufacturer.
– System Identification Number (SID) - a number
assigned to the particular wireless carrier to which the
telephone’s user has subscribed.

How Cellular Telephony Works
(continued)

Advanced Mobile Pone Service
(AMPS)

• A first generation
cellular technology
that encodes and
transmits speech as
analog signals.

Time Division Multiple Access
(TDMA)

Code Division Multiple Access
(CDMA)
• Each voice signal is digitized
and assigned a unique code,
and then small components of
the signal are issued over
multiple frequencies using the
spread spectrum technique.

Global System for Mobile Communications
(GSM)
• A version of time division multiple access (TDMA) technology,
because it divides frequency bands into channels and assigns signals
time slots within each channel.

• Makes more efficient use of limited bandwidth than the IS-136 TDMA
standard common in the United States.

• Makes use of silences in a phone call to increase its signal
compression, leaving more open time slots in the channel.

Wireless Local Loop (WLL)

• A generic term that describes a wireless link used in the
PSTN to connect LEC central offices with subscribers.

• Acts the same as a copper local loop.

• Used to transmit both voice and data signals.

Local Multipoint Distribution Service
(LMDS)
• A point-to-multipoint, fixed wireless technology that was
conceived to supply wireless local loop service in densely
populated urban areas and later on a trial basis to issue
television signals.

• A disadvantage is that its use of very high frequencies
limits its signal’s transmission distance to no more than
4km between antennas.

Multipoint Multichannel Distribution
System (MMDS)
• Uses microwaves with frequencies in the 2.1 to 2.7 GHz
range of the wireless spectrum.

• One advantage is that because of its lower frequency
range, MMDS is less susceptible to interference.

• MMDS does not require a line-of-sight path between the
transmitter and receiver.

Short Message Service (SMS)
• Globally accepted wireless service that enables the transmission of
alphanumeric messages between mobile devices and external systems
• Available in US on GSM-based PCS as well as TDMA and CDMA
based cellular systems
• Short Message Service Center (SMSC) acts as a relay and
store and forward system for messages
• Point to point delivery of messages
• Active mobile handset is able to receive or send a short message at any
time, independent of whether a voice or data call is in progress
• Utilizes out-of-band packet delivery and low-bandwidth message
delivery
• Guarantees delivery of the short message by the network. Temporary
transmission failures are identified, and the message is stored in the
network until the destination becomes available

2.5G, which stands for "second and a
half generation," is a cellular wireless
technology developed in between its
predecessor, 2G, and its successor, 3G.

"2.5G" is an informal term, invented
solely for marketing purposes, unlike
"2G" or "3G" which are officially
defined standards based on those
defined by the International
Telecommunication (ITU). The
term "2.5G" usually describes a 2G
cellular system combined with
General Packet Radio Services
(GPRS )

A 2.5G system may make use of 2G system
infrastructure, but it implements a
packet-switched network domain
in addition to a circuit-switched domain.

2.5 G
 2G (GSM standard)—GPRS (General
Packet Radio Service )was introduced in
2001. It added packet switching protocols to
mobile communications technology and
TCP/IP thus making possible the reading and
sending of e-mails, instant messaging (IM),
and browsing the Internet. SMS or short
message service is heavily used.

 2.5 G added MMS.

MMS

 Multimedia Message Service, a store-and-forward method of
transmitting graphics, video clips, sound files and short text messages
over wireless networks using the WAP protocol. Carriers deploy
special servers, dubbed MMS Centers (MMSCs) to implement the
offerings on their systems.
 MMS also supports e-mail addressing, so the device can send e-mails
directly to an e-mail address. The most common use of MMS is for
communication between mobile phones. MMS, however, is not the
same as e-mail. MMS is based on the concept of multimedia
messaging. The presentation of the message is coded into the
presentation file so that the images, sounds and text are displayed in a
predetermined order as one singular message. MMS does not support
attachments as e-mail does.
 To the end user, MMS is similar to SMS.

2.5G

 An enhancement to 2G networks that allows them to
operate in a "packet switched" manner
 2.5G networks incorporate 2G technology with GPRS'
higher speeds to support data transport. 2.5G is a bridge
from the voice-centric 2G networks to the data-centric 3G
networks.
 GPRS (General Packet Radio Service) is a radio
technology for GSM networks that adds packet-switching
protocols. As a 2.5G technology, GPRS enables high-
speed wireless Internet and other data communications.
GPRS networks can deliver SMS, MMS, email, games,
and WAP applications.

GPRS

 GPRS (General Packet Radio Service) is a specification for data
transfer on TDMA and GSM networks.
 The theoretical limit for packet switched data is
approx. 170 kb/s.
 A realistic bit rate is 30-70 kb/s. .
 GPRS supports both TCP/IP and X.25 communications.
 It provides moderate speed data transfer, by using unused TDMA
channels on a GSM network.
 GSM circuit switch connections are still used for voice, but data is
sent and received in "packets" in the same way as it would be in the
fixed internet environment.
 The advantage is that network resources are used more efficiently.
Rather than maintaining a circuit for the duration of the connection,
which ties up resources regardless of whether anything is actually
being sent or received, GPRS only consumes resource when
information packets are transmitted.

HSCSD

 HSCSD (High Speed Circuit Switched Data) is a
specification for data transfer over GSM networks.
HSCSD utilizes up to four 9.6Kb or 14.4Kb time slots, for
a total bandwidth of 38.4Kb or 57.6Kb.
 14.4Kb time slots are only available on GSM networks
that operate at 1,800Mhz. 900Mhz GSM networks are
limited to 9.6Kb time slots. Therefore, HSCSD is limited
to 38.4Kbps on 900Mhz GSM networks. HSCSD can
only achieve 57.6Kbps on 1,800Mhz GSM networks.

HSCSD vs. GPRS

 HSCSD has an advantage over GPRS in that HSCSD supports
guaranteed quality of service because of the dedicated
circuit-switched communications channel. This makes HSCSD a
better protocol for timing-sensitive applications such as image or
video transfer.
 GPRS has the advantage over HSCSD for most data transfer because
HSCSD, which is circuit-switched, is less bandwidth efficient with
expensive wireless links than GPRS, which is packet-switched.
 For an application such as downloading, HSCSD may be preferred,
since circuit-switched data is usually given priority over packet-
switched data on a mobile network, and there are few seconds when
no data is being transferred.

ISM Frequency Bands
The three ISM frequency bands are the only ones available for unlicensed wireless
transmission in the US. Only one band has world-wide availability.

 Industrial, Scientific, and
Medical (ISM) spread spectrum
modulation
 902-928 MHz
 2.4-2.4835 GHz (home of
microwave oven band)
 5.725-5.850 GHz
 under 1 watt transmitter output
power
 more bandwidth with higher
frequencies, which support
higher data rates.

Lifi….the latest technology in wireless
communication
• LiFi is a new class of high intensity light source of
solid state design bringing clean lighting solutions
to general.
• With energy efficiency, long useful lifetime, full
spectrum and dimming , LiFi lighting applications
work better compared to conventional approaches.
• This technology gives the general construction of
LiFi lighting systems and the basic technology
building blocks behind their function.

Advantages
• Using this innovative technology 10,000 to 20,000
bits per second of data can be transmitted
simultaneously in parallel using a unique signal
processing technology and special modulation

• As communication technology is expanding at a
rapid pace we are running out of radio frequency
spectrum but this new visible light spectrum has
10,000 times more capacity than radio frequency.

•

• Cellular masts or base stations worldwide uses a lot of
energy particularly for cooling and it operates at only
five percent efficiency whereas LiFi technology can
transmit data through the 14 billion light bulbs
already installed worldwide. So it is virtually free .

• The whole process of transmitting data through light
is more energy efficient than using radio frequency.

Applications
• Can be used in the places where it is difficult to lay the
optical fiber like hospitals. In operation theatre LiFi can
be used for modern medical instruments.
• In traffic signals LiFi can be used which will
communicate with the LED lights of the cars and
accident numbers can be decreased.
• Thousand and millions of street lamps can be
transferred to LiFi lamps to transfer data.

Conclusion
• The design and construction of the LiFi light
source enable
• efficiency,
• long stable life,
• full spectrum intensity
• that is digitally controlled
• and easy to use.

Any Questions ?

Or else lets EDGE

Going through the
Edge,
from 2.5G to 3G

2G/2.5G Voice & Data Handset still
dominates the market while 2.75G is
trying to fill the technology gap before
3G is mature.

Advancement of Cellular Technology
Bluetooth™ WLAN
All IP RAN
2G 2.5G 2.75G 3G 4G
EGPRS EDGE
Western Europe EDGE Phase2
Phase1 Rel4,5, 6
Rel99 and beyond FDD:WCDMA

GPRS-136HS
GSM EDGE UWB
GPRS
TDD:WCDMA

EDGE
EDGE

Phase II
Classic
TD:CDMA SDR
TDMA EDGE TD:SCDMA HSDPA
Compact UMTS ….
GAIT*
PDC
iDEN IMT2000
GERAN UTRAN
cdma2000™ cdma2000™
CDMA 1XRTT 1XEV-DV
cdma2000™
1xEV-DO
<9.6kbps <115kbps <384kbps <384kbps <2Mbps >2Mbps

2001 2002 2003 2004

•GSM ANSI 136 Interoperability Team
•GERAN – GSM EDGE Radio Access Network
•UTRAN –UMTS Terrestrial Radio Access Network

EDGE
• Enhanced Data Rates for Global Evolution (EDGE) is a bolt-on
enhancement to 2G and GPRS networks. This technology is
compatible with TDMA and GSM networks. EDGE uses the same
spectrum allocated for GSM850, GSM900, GSM1800 and GSM1900
operation.
• Instead of employing GMSK (Gaussian minimum-shift keying) EDGE
uses 8PSK (8 Phase Shift Keying) producing a 3bit word for every
change in carrier phase. This effectively triples the gross data rate
offered by GSM. EDGE, like GPRS, uses a rate adaptation algorithm
that adapts the modulation and coding scheme (MCS) used to the
quality of the radio channel, and thus the bit rate and robustness of
data transmission. It introduces a new technology not found in GPRS,
Incremental Redundancy, which, instead of retransmitting disturbed
packets, sends more redundancy information to be combined in the
receiver. This increases the probability of correct decoding.

EDGE provides data speed
three times that of GPRS

• EDGE is a mobile network radio technology
that allows current GSM networks to offer 3G
services within existing frequencies. As an
evolution of GSM/GPRS, EDGE is an upgrade
to GPRS' data and GSM's voice networks..

Why 3G?
• Higher bandwidth enables a range of new applications!!
• For the consumer
– Video streaming, TV broadcast
– Video calls, video clips – news, music, sports
– Enhanced gaming, chat, location services…
• For business
– High speed teleworking / VPN access
– Sales force automation
– Video conferencing
– Real-time financial information

3G

• 3G networks promise next-generation service with
transmission rates of 144Kbps and higher that
can support multimedia applications, such as
video, video conferencing and Internet access.
Both UMTS (WCDMA) and EDGE will support
3G services. 3G networks operate on a different
frequency than 2G networks.

Emerging Third Generation (3G)
Technologies
The promise of these technologies is that a user can
access all her telecommunication services from one
mobile phone.

• CDMA2000 - a packet switched version of CDMA.

• Wideband CDMA (W-CDMA) - based on
technology developed by Ericson, is also packet-
based and its maximum throughput is also 2.4 Mbps.

3G
 3G—UMTS (Universal Mobile
Telecommunications System)--Can reach
384 kbps. The technology made video
phones, watching streaming video,
downloading music and getting broadband
access possible. UMTS can be used on
both mobile phones and computers. It is
capable of transferring 385 kbps for mobile
systems and up to 2Mbps for stationary
systems.

3G services in Asia
• CDMA (1xEV-DO)
– Korea: SKT, KTF
– Japan: AU (KDDI)
• WCDMA / UMTS
– Japan: NTT DoCoMo, Vodafone KK
– Australia: 3 Hutchinson
– Hong Kong: 3 Hutchinson

IS-95 (CdmaOne)
 IS-95: standard for the radio interface
 IS-41: standard for the network part
 Operates in 800MHz and 1900MHz bands
 Uses DS-CDMA technology (1.2288 Mchips/s)
 Forward link (downlink): (2,1,9)-convolutional code,
interleaved, 64 chips spreading sequence (Walsh-Hadamard
functions)
 Pilot channel, synchronization channel, 7 paging channels, up
to 63 traffic channels
 Reverse link (uplink): (3,1,9)-convolutional code, interleaved,
6 bits are mapped into a Walsh-Hadamard sequence,
spreading using a user-specific code
 Tight power control (open-loop, fast closed loop)

Advantages of CDMA Cellular
 Frequency diversity – frequency-dependent
transmission impairments have less effect on
signal
 Multipath resistance – chipping codes used for
CDMA exhibit low cross correlation and low
autocorrelation
 Privacy – privacy is inherent since spread
spectrum is obtained by use of noise-like signals
 Graceful degradation – system only gradually
degrades as more users access the system

Drawbacks of CDMA Cellular
 Self-jamming – arriving transmissions from
multiple users not aligned on chip
boundaries unless users are perfectly
synchronized
 Near-far problem – signals closer to the
receiver are received with less attenuation
than signals farther away
 Soft handoff – requires that the mobile
acquires the new cell before it relinquishes
the old; this is more complex than hard
handoff used in FDMA and TDMA schemes

CDMA Design Considerations
 RAKE receiver – when multiple versions of
a signal arrive more than one chip interval
apart, RAKE receiver attempts to recover
signals from multiple paths and combine
them
o This method achieves better performance than
simply recovering dominant signal and treating
remaining signals as noise
 Soft Handoff – mobile station temporarily
connected to more than one base station
simultaneously

RAKE Receiver
 RAKE Receiver has to estimate:
o Multipath delays
o Phase of multipath components
o Amplitude of multipath components
o Number of multipath components
 Main challenge is receiver synchronization in
fading channels

Forward Link Channels
 Pilot: allows the mobile unit to acquire timing
information, provides phase reference and
provides means for signal strength comparison
 Synchronization: used by mobile station to obtain
identification information about cellular system
 Paging: contain messages for one or more mobile
stations
 Traffic: the forward channel supports 55 traffic
channels

Forward Traffic Processing Steps
 Speech is encoded at a rate of 8550 bps
 Additional bits added for error detection
 Data transmitted in 2-ms blocks with
forward error correction provided by a
convolutional encoder
 Data interleaved in blocks to reduce effects
of errors
 Data bits are scrambled, serving as a
privacy mask
o Using a long code based on user’s electronic
serial number

Forward Traffic Processing Steps
 Power control information inserted into traffic
channel
 DS-SS function spreads the 19.2 kbps to a rate of
1.2288 Mbps using one row of 64 x 64 Walsh
matrix
 Digital bit stream modulated onto the carrier
using QPSK modulation scheme

Reverse Traffic Processing Steps
 Convolutional encoder at rate 1/3
 Spread the data using a Walsh matrix
o Use a 6-bit piece of data as an index to the Walsh matrix
o To improve reception at base station
 Data burst randomizer
 Spreading using the user-specific long code mask

Third-Generation Capabilities
 Voice quality comparable to the public switched
telephone network
 144 kbps data rate available to users in high-
speed motor vehicles over large areas
 384 kbps available to pedestrians standing or
moving slowly over small areas
 Support for 2.048 Mbps for office use
 Symmetrical/asymmetrical data transmission rates
 Support for both packet switched and circuit
switched data services

Typical application: road traffic

UMTS, WLAN, h oc
DAB, GSM, ad
TETRA, ...

Personal Travel Assistant,
DAB, PDA, laptop,
GSM, UMTS, WLAN,
Bluetooth, ...

1.4.1

Overlay Networks - the global goal
integration of heterogeneous fixed and
mobile networks with varying
transmission characteristics

regional

vertical
hand-over

metropolitan area

campus-based
horizontal
hand-over

in-house

1.23.1

Influence of mobile communication to the layer model

Application layer  service location
 new applications, multimedia
 adaptive applications
Transport layer
 congestion and flow control
 quality of service
 addressing, routing,
Network layer device location
 hand-over
 authentication
Data link layer
 media access
 multiplexing
 media access control
Physical layer  encryption
 modulation
 interference
 attenuation
 frequency

3G Standards
• 3G Standard is created by ITU-T and is called as IMT-
2000.
• The aim of IMT-2000 is to harmonize worldwide 3G
systems to provide Global Roaming.

Upgrade paths for 2G Technologies

2G IS-95 GSM- IS-136 & PDC

GPRS
IS-95B
2.5G
HSCSD EDGE

Cdma2000-1xRTT W-CDMA
3G Cdma2000-1xEV,DV,DO EDGE
TD-SCDMA
Cdma2000-3xRTT
3GPP2 3GPP

3G: Winners & Losers ??
 UMTS
 Huge delays (terminals availability)
 Very expensive license fees
 Clear evolution path
 HSxPA (Peak Data Rates), LTE (Long Term Evolution)
(Network Simplification)
 WCDMA
 Compelling peak data rates (EV-DO)
 Unclear evolution path
 3xRTT? WIMAX?

UMTS Frequency Spectrum
• UMTS Band : 1900-2025 MHz and 2110-2200 MHz for 3G transmission.
• Terrestrial UMTS (UTRAN) : 1900-1980 MHz, 2010-2025 MHz, and 2110-
2170 MHz bands

IS-95A

CDMA was commercially introduced in 1995 with IS-95A or
cdmaOne. IS-95A is the CDMA-based second generation (2G)
standard for mobile communication. The following
are the key aspects of this standard:
• Support for data rates of upto 14.4 kbps
• IS-95A has been used exclusively for circuit-switched voice
• Convolutional Channel coding used
• Modulation technique used is BPSK

IS-95B

IS-95B or cdmaOne is the evolved version of IS-95A and is
designated as 2.5G. IS-95B maintains the Physical Layer of IS-95A,
but due to an enhanced MAC layer, is capable of providing for higher
speed data services. The following are the key aspects of the
standard:
• Theoretical data rates of upto 115 kbps, with generally experienced
rates of 64 kbps
• Additional Walsh codes and PN sequence masks, which enable a
mobile user to be assigned up to eight forward or reverse code
channels simultaneously, thus enabling a higher data rate
• Code channels, which are transmitted at full data rates during a
data burst
• Convolutional Channel coding
• Binary Phase Shift Keying (BPSK) as the Modulation technique
used

CDMA 2000 1X
•Supports theoretical data rates of upto 307 kbps, with generally
experienced rates of 144 kbps
• The newly introduced Q-PCH of CDMA 2000 enables the mobile to
be informed about when it needs to monitor F-CCCH and the Paging
Channel, thus improving on the battery life
• Introduction of Radio Configurations – Transmission formats
characterized by physical layer parameters such as data rates,
modulation characteristics, and spreading rate. RCs help in providing
for additional data rates.
• Quality and Erasure indicator bits (QIB and EIB) on the reverse
power control sub channel. These help in indicating to the BS about
bad frames or lost frames received at the mobile station, so that they
can be retransmitted
• Code channels are transmitted at full data rates during a data burst
• Convolutional and Turbo coding techniques used
• Modulation technique used is QPSK

CDMA 2000 3X

• Offering data speeds up to 2 Mbps
• Using three standard 1.25 MHz channels within a 5 MHz band
• Leveraging deployment experiences, and manufacturers’ learning
curves of today’s widely adopted, commercially available CDMA systems
• Using Convolutional and Turbo coding techniques
• Using QPSK as the Modulation technique

1X EV-DO

• Supporting data rates of up to 2.4 Mbps
• Having no backward-compatibility with CDMA 2000
• Including two inter-operable modes: an integrated 1x mode optimized
for voice and medium data speeds, and a 1xEV mode optimized for
non real-time high capacity/high speed data and Internet access
• Providing Adaptive Rate Operation with respect to channel conditions
• Providing Adaptive modulation and coding
• Providing Macro diversity via radio selection
• Providing an always-on operation of 1xEV-DO terminals in the active
state
• Using a multi-level modulation format (QPSK, 8-PSK, 16-QAM)

1xEV-DV

• Backward compatible with CDMA 2000.
• EV-DV can be easily extended to operate in 3x mode under the
framework of current system.
• Forward peak data rate : 3.072 Mbps.
• Reverse peak data rate: 451.2 kbps.
• Addition of three new channels to f/w link and reverse link for packet
data operation and its support.
• Adaptive modulation and coding : QPSK, 8- PSK, 16-QAM
• Variable frame duration
• Mobile station can select one of N base stations.
• DTX transmission supported for saving battery life.

3G: Technology Summary
 Technology Convergence on Wideband-CDMA
 WCDMA
 Successor to CDMA, 4 core standards – 1xRTT, 1x EV-DO, 1x EV-
DV, 3xRTT
 1xRTT provides 2x voice capacity increase over CDMA and a peak
data rate of 144kbps
 EV-DO Rev A provide peak data rates of 3.1 downlink / 1.8 uplink
(800kbps typical)
 UMTS (Universal Mobile Telephone System)
 Successor to GSM, based on W-CDMA
 Peak data rates of up to 1920kbps (384kbps typical)
 HSDPA peak data rate of up to 14.4Mbps

Global Subscriber Counts

2.5 Bn

GSM
2 Bn

1.5 Bn

W-CDMA
1 Bn

0.5 Bn
CDMA

0
2006 2007 2008 2009 2010 2011

The future of cellular radio: G3?
• Market increases quickly over the years
worldwide, often beyond projection.
• Cost continues to drop: $.45/minute in the
early 90s to 9.4 cents in 2000.
• G3 proposals are under consideration
– Calls for data rate from 144 kbps (fast moving)
to 384 kbps (pedestrian).
– Supports global roaming

3.5G (HSPA)
High Speed Packet Access (HSPA) is an amalgamation
of two mobile telephony protocols,
High Speed Downlink Packet Access
(HSDPA)
and
High Speed Uplink Packet Access
(HSUPA),
that extends and improves the performance of existing
WCDMA protocols

3.5G features
3.5G introduces many new features that will enhance the
UMTS technology in future. 1xEV-DV already supports
most of the features that will be provided in 3.5G. These
include:
- Adaptive Modulation and Coding
- Fast Scheduling
- Backward compatibility with 3G
- Enhanced Air Interface

3.5G (HSDPA)

High Speed Downlink Packet Access

Why HSDPA?

Comparison Between 3G & 3.5G.
 Data Rate ( 2Mbps -----> 10 Mbps)

 Modulation ( QPSK -----> QPSK&16QAM)

 TTI( 10ms ----> 2ms )
Reducing delay ” T T I ”.

HSDPA Features

Hybrid Automatic Repeat Request
Fast cell site selection
Adaptive Modulation and Coding

3.5G

3.5G or HSDPA (High Speed Downlink Packet Access) is an
enhanced version and the next intermediate generation of 3G
UMTS. It comprises the technologies that improve the Air Interface
and increase the spectral efficiency, to support data rates of the
order of 30 Mbps. 3.5G introduces many new features that will
enhance the UMTS technology in future. 1xEV-DV already
supports most of the features that will be provided in 3.5G. These
include:
• Adaptive Modulation and Coding
• Fast Scheduling
• Backward compatibility with 3G
• Enhanced Air interface

CDMA2000 evolution to 3G

IS-95B CDMA2000 1xEV-DO: Evolved Data Optimised
Uses multiple code channels Third phase in CDMA2000 evolution
Data rates up to 64kbps Standardised version of Qualcomm High Data Rate (HDR)
Many operators gone direct to 1xRTT Adds TDMA components beneath code components
Good for highly asymmetric high speed data apps
IS-95B Speeds to 2Mbps +, classed as a “3G” system
Use new or existing spectrum
CDMA
IS-95A CDMA2000
1xEV-DO 1xEV-DV
3xRTT
IS-95A
14.4 kbps 1xRTT
CDMA2000 1x Evolved DV
Core network
CDMA2000 1xRTT: single carrier Fourth phase in CDMA2000 evolution
re-used in
RTT Still under development
CDMA2000
First phase in CDMA2000 evolution Speeds to 5Mbps+ (more than 3xRTT!)
Easy co-existence with IS-95A air interface Possible end game.
Release 0 - max 144 kbps
Release A – max 384 kbps
Same core network as IS-95

What next after 3G?
• The future path has fractured 3G & 3G & 4G &
WLAN & WLAN & WLAN &
into a number of possibilities Brdcst Ad-hoc Brdcst
2.5G &
• Operators and vendors must WLAN
create viable strategies to 3G+ & 4G &
3G+ &
prosper within this complexity 3G &
WLAN
WLAN & WLAN &
WLAN Ad-hoc Ad-hoc

GPRS/ 4G &
EDGE 3G+ WLAN
(2.5G)

GSM W-CDMA 4G
(2G) (3G)

1990 2000 2010

Long-Term Evolution

LTE (3.9G)

and

LTE-Advanced (4G)

After comparison the LTE-Advanced
(4G) is better than LTE (3.9G) in some
specifications such as:
• LTE-Advanced 4G have Data rates up to 1Gbps in stationary
scenarios, Coverage enhancements for high
• frequency bands, LTE-Advanced will be a smooth evolution of
LTE, Numerology and access technologies will be the same,
Bandwidth up to 100MHz supported, Contiguous and non-
contiguous carrier aggregation,
• New technologies are being proposed, Enhanced MIMO,
cooperative transmission, relaying etc.
• LTE-Advanced is a very flexible and advanced system, further
enhancements to exploit spectrum availability and advanced
multi-antenna techniques.

Two Key technologies are evolving to meet the Wireless
Broadband Requirements

4G Air Interfaces
Wide Area

1x
HRPDA
Mobile

CDMA EVDO
3GPP2
2000-1X 1x EVDV 1x EVDV MOBILE
Rel. C Rel. D BROADBAND

GSM GPRS EDGE UMTS HSPA LTE 3GPP
Coverage/Mobility

802.16e
(Mobile WIMAX)
Metro Area

Mobile Industry
Nomadic

802.16a/d
(Fixed NLOS)

802.11n
Fixed Wireless Industry (smart antennas)
802.11
Local Area

802.16 Mesh extns.
Fixed

(Fixed LOS)
Dial Up DSL Experience
802.11b/a/g
Data Rates (kbps)
100,000 +
Higher Data Rate / Lower Cost per Bit

4G (LTE)
• LTE stands for Long Term Evolution
• Next Generation mobile broadband
technology
• Promises data transfer rates of 100 Mbps
• Based on UMTS 3G technology
• Optimized for All-IP traffic

4G: Anytime, Anywhere Connection
• Also known as ‘Mobile Broadband everywhere’
• ‘MAGIC’
– Mobile Multimedia Communication
– Anywhere, Anytime with Anyone
– Global Mobility Support
– Integrated Wireless Solution
– Customized Personal Service
• According to 4G Mobile Forum, by 2008 over $400 billion
would be invested in 4G mobile projects.
• In India, communication Minister Mr. Dayanidhi Maran,
has announced a national centre of excellence to work in
4G arena.

4G
 4G—The fourth generation cell phone is
being championed in Japan. It will boost the
data rates to 20 Mbps. These speeds enable
high quality video transmission and rapid
download of large music files. The first 4G
phones appeared in 2006.

4G: Data rate Facts
 Transmission at 20 Mbps
 2000 times faster than mobile data rates
 10 times faster than top transmission rates planned in final
build out of 3G broadband mobile
 10-20 times faster than standard ADSL services.
 Companies developing 4G technology
 Cellular phone companies: Alcatel, Nortel, Motorola,
 IT Companies: Hughes,HP,LG Electronics

…and Beyond
 Technology Convergence on OFDM (Orthogonal
Frequency Division Multiple Access)

 HSOPA
 Improved bandwidth, latency over UMTS/HSxPA
 Radio technology based on MIMO-OFDM, peak data
rates of up to 70Mbps
 Network simplification

Operator Objectives
Voice+  Mobile Operators
Growth to
Wireless
 Subscriber growth
 Wireless Data / 3G
 Wireline Substitution

 Fixed Operators
 Broadband Line Growth
 Revenue Protection

 Cable, Satellite, ISP
 Network Leverage
Data+
Growth to
 New Markets
Broadband  Video Play

Network Goals are Similar
Differentiation on Access & Business goals

Evolution of Cellular Networks

1G 2G 2.5G 3G 4G

3G/HSDPA vs. WIMAX/LTE Network Architecture

Traditional Cellular Architecture Carrier Access Point (CAP) Architecture

Internet PSTN Internet PSTN

GGSN Media
Gateway Data VoIP
Gateway Gateway
or IMS or IMS
SGSN MSS
Operator’s
IP Network

Base Station
Controllers

CAP
Base Stations Access Points Controller

Any off-the-shelf
= IP network with = Lower Cost!
Mobile IP support

“By 2012, 18 million laptops will have WIMAX
built-in” - Intel

vehicles

MP3 player
CHANGING THE WAY WE:
pdas
indoor CPE

outdoor CPE
Video
cameras
set top boxes

handsets
laptops
digital cameras

WIMAX technology will in most
consumer devices
televisions
Gaming consoles

Higher frequency selectivity

Severer power limited condition

Under these conditions, system should be optimized
with considering the trade-off between cell throughput and cell coverage

Example 1: Self-deployment of eNodeBs
• More autonomous deployment becomes
obviously more interesting
– Without planning of radio parameters
– Also useful study item for home NodeB deployment
• Start with minimal coverage and gradually increase cell size
• Radio scanning to find unused resources
• Negotiation with neighbor cells about spectrum resource usage

Example 2: Self Neighbor Scanning
HeNB
• Operator will have many thousands/millions of home
eNB.
– Human operation based configuration of each hEB is not
economical.
• Home eNB frequently scan
– All neighbors of own or other PLMN ID
• heNB capable of scanning neighboring macro cells/frequencies
– All neighbors of other RAT
• heNB capable of scanning neighboring UMTS/WIMAX cells
– Scan results are sent to the central server

Example 3: Self Coordinating
Interference Management
• To coordinate scheduling in interfering cells,
– Alt1: Semi-static restrictions for users close to cell
borders
• Self coordination between cells set by rules
• Agreed in Release 8 as HII
– Alt2: Short time-scale coordination
• Very high speed of coordination for re-optimization
based on load in different cells

Self Coordinating Interference
Management

Example 4: HO Parameterization
Optimization
• Handover parameter optimization triggered
by “performance problems”
• Optimization of individual neighbor-to-
neighbor parameters
– E.g. HO hysterisis control
• Slow optimization loop
– Cautiously change parameter to avoid user
perceivable degradation
– Evaluate results through performance monitoring

Example 5: UE Measured
Performance Reporting

Example 6: Common Channel Self
Optimization

RACH, PCH, BCH Power optimizations

• Instead of drive tests: slow optimization based
on UE reports
– received signal strength, channel quality, neighbor
signal strength
– Ideally also location of UE
• Cautious adjustment of power in one cell,
monitoring of effects
– search optimal settings, e.g. gradient descent

Example 7: Reduction of Energy
Consumption by RAN

Reduction of Energy Consumption by
RAN
• Partial or complete eNB power down during
low load, e.g. at night
• Stored profiles used to reconfigure radio
parameters for the new topology
• Wake up based on timers or external triggers

Advantages in Femto cell deployment
in a Radio Aspect

LTE vs UMTS
• Functional changes compared to the current
UMTS architecture

NGN Context
Evolved hardware technologies
+
Improved network bandwidth
=
Entertainment apps on mobile

208

When you are NOT mobile, you use

209

When you are mobile, you use

210

Millions of passengers per day!

211

Market promoters
world's 25th-largest consumer electronics producer
and sixth-largest television producer
(after Samsung, LG, Sony, Panasonic and Sharp).

January 16- 2010
China Star Optoelectronics Technology (CSOT)’s
8.5-generation LCD panel project was officially launched

2005
The sales volume of TCL color TV sets
ranked first place in the world.

also Refer ….
1. Erik Dahlman, Stefan Parkvall, and Johan Skold, 4G
LTE/LTE-Advanced for Mobile Broadband, Elsevier
Ltd., 2011, pp.11-12,379-380.
2. Christian Mehlfuhrer, Martin Wrulich, Josep
Colom Ikuno, Dagmar Bosanska, Markus Rupp,
SIMULATING THE LONG TERM EVOLUTION
PHYSICAL LAYER, 17th European Signal Processing
Conference (EUSIPCO 2009) Glasgow, Scotland,
August 24-28, 2009,pp.1.
3. FAROOQ KHAN, LTE for 4G Mobile Broadband Air
Interface Technologies and Performance,
Cambridge University Press, New York, 2009, pp.3.

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