Overview of Cellular Network

1. Introduction

1.1 Motivation

Implementation
of third-generation (3G) cellular systems is meaning of implementation of WCDMA
which is one of the main technology of third-generation. WCDMA is based on
radio access technique. ETSI Alpha group proposed the WCDMA technology for the
fifth time and has finalized in the year of 1999. ITU has standardized the
technique under the name of “IMT-2000 direct spread” and it’s also known of
UTMS. Because of complexity and versatility of WCDMA, it’s always a big
challenge for the scientist and researcher to implement WCDMA. The reason WCDMA
is viewed as a complex system because of arithmetic multiplicity of
transmission and receiving of signals, multiplicity of computing each single
device result and the multiplicity of the entire system. The main theme of the
WCDMA system is, user can simultaneously transmit data in different rates and
the transmission varies over time. Using of CDMA air transmission system
instead of using TDMA system WCDMA transmits higher data rates in to the GSM
systems. UMTS uses the WCDMA systems which are based on CDMA. WCDMA is the
dominating 3G technology, providing higher capacity for voice and data and
higher data rates WCDMA dominates the current 3G technology because of its
higher capacity for voice and data, which means the overall higher data rate.
Need for higher transmission of data rates in mobile services in today’s modern
world requires a new technology which is able to perform higher data. WCDMA
enables better use of available spectrum and more cost-efficient network
solutions WCDMA offers the use of better available spectrum in the network
which is also cost effective. Switching from GSM to WCDMA is also cost
effective. Operators can still use the core network of GSM and 2G/2.5G
services.

Orthogonal Frequency Division
Multiplexing (OFDM), uses FDM modulation technique to broadcast the high amount
of digital data through the radio wave among the wireless networks. OFDM works by splitting the radio signal into multiple
smaller sub-signals that are then transmitted simultaneously at different
frequencies to the receiver the main theme of OFDM is concurrent broadcasting
of high amount of data using different frequencies by splitting the radio wave
into multiple smaller sub-signals to the receiver. OFDM cuts the size of
crosstalk in signal broadcasting. 802.11a WLAN, 802.16 and WiMAX technologies
use OFDM. It’s also used in the ETSI’s HiperLAN/2 standard. In addition,
Japan’s Mobile Multimedia Access Communications (MMAC) WLAN broadband mobile
technology uses OFDM. In FDM, multiple signals, or carriers, are sent
concurrently over different frequencies between two points. However, the
feedback of FDM is: radio waves can travel different ways from broadcaster to receiver
(by bouncing off buildings, mountains and even passing airplanes); so the
receiving end faces the problem to sort all the resulting data. Orthogonal FDM
uses the technique of splitting smaller sub-carriers of frequencies to deal
with this multi-path problem. This reduces multi-path distortion and reduces RF
interference which allows greater result Multi-path distortion and Radio
Frequency interferences are minimized through this way.

1.2 Evolution of Cellular
Communications

During the last few years wireless
communication system has been transferred from low data-rate system to high
data-rate system containing of voice, images and even to videos. Traditional
systems as like modems, cellular systems,802.11b local area network which used
to have data rates of only to few Kbps has been switched to high data-rate with
few Mb per second containing of multimedia with videos. Even data rate of few Mbps
is going towards the few GB per second in the recent technologies as like DSL, cable modems, and 802.11n local area networks
(LANs) and ultra-wideband personal area networks (PANs). Wireless
telecommunication started during the years of 80’s named to The First
generation Systems (1G) using Advanced Mobile Phone Service (AMPS) for the cellular
analogue voice. During the year of 90’s 1G standard has been switched to Second
Generation System (2G). Digital voice with low bit data rates has been taken
place to the analogue voice. An example
of such a cellular system is IS-54. At the same time, wireless local area networks
started becoming in service starting at 1 Mbps for 802.11b standards and
extending to 11 Mbps close to the year 000 Standard for 802.11b local area
networks has been improved from 1 Mbps to 11 Mbps by the year of 2000. Reason
to this higher data rate in local area network was the shorter distance to
cover than to cover a large distance in the cellular network. To support the recent
3G standard with the data of multimedia and videos data rates has been improved
to 100 Mbps. On the other hand data rates of the wireless LANs standard of
802.11a and 802.11g has been improved to 100 Mbps. Near future Fourth
Generation System (4G) will not only transmit very high data rates but also
will provide Quality of Service (QoS) with the technique of IP. Below figure 01
shows the evolution of wireless communication systems as they have gone from 1G
to 4G systems.

Figure 1.1: Evolution of communications
systems.

1.3 Cellular Communications Review

Wireless
transmission are increasing at an amazing speed, with affirmation of rapid
growth in the areas of mobile users and terminals, mobile and wireless access
networks, and mobile services and applications. It is the perfect time to
explore the new technology like 4G mobile communication, because:

Practicability,
History over the last few decades shows that standards of the wireless
communication have been changed in every decade. In the current decade we
are at the end stage of the 3G standardization phase and opening stage of
the deployment of 3G.
To employ the
subscriber demand of the 21^st century it’s not the luxury that
to have multimedia high data rates in the 3G system but necessity to have
3G goals. Many of the 3G problems have not solved in the 3G but to intend
to solve in the 4G system.

1.3.1 First-Generation Systems

First
Generation Systems (1G) means the system which used the network of analogue
traffic system. AT&T is the first company in North America to introduce
first generation system to the customers in during the year of early 1980’s.
AT&T named the system as Advanced Mobile Phone Service (AMPS). Gradually
AMPS technology has been introduced to the countries of South America,
Australia and China. 1G constructs the primary architecture of cellular
communications and clarifies lots of foundational obstacle, such as adoption of
cellular architecture, multiplexing frequency band, roaming across domain,
non-interrupted communication etc. First Generation System wasn’t able to
support lot of services to the customer; primary goal was to support voice
chat.

Band of base station	869 to 894 MHz
Band for Mobile Unit	824 to 849 MHz
Forward channels and reverse channels spacing	45 MHz
Channel bandwidth	30 KHz
Size of full-duplex voice channels	790
Size of full-duplex control channels	42
Mobile unit maximum power	3 watts
Cell size, radius	2 to 20 km
Modulation, voice channel	FM, 12-KHz peak deviation
Modulation, control channel	FSK, 8-KHz peak deviation
Data transmission rate	10 kbps
Error control coding	BCH (48, 36, 5) and (40,28, 5)

Table 1.1: AMPS Parameters.

1.3.2 Second-Generation Systems

People
started to adopt First Generation AMPS mobile communication in a rapid way.
High volume of users started to warn the slower analogue system. Developers
started to think a new system which will provide higher quality signals. It’s
the time to develop Second-generation systems, which will satisfy high volume
of customer’s needs. 2G systems have been promote to provide higher quality
signals, high data rates for support of digital communication, and bigger
capacity. 2G systems will use digital technology which will guarantee more accurate
signals where as analogue communication was the technology for the First
Generation system. Whereas, both of the
system use digital signaling to establish connection from radio towers to the
telephone subscriber. Second Generation system could be divided in to TDMA or
CDMA standard according to the multiplexing they use. The main 2G standards
are: GSM, iDEN, IS-136 (D-AMPS), PDC are the example of TDMA-based second
generation standards. CdmaOne which is also called IS-95 is CDMA-based. Second
and Half Generation system is in the middle of Second generation and Third
Generation system mobile technology. Designers have to name “2.5G” system
because they have introduced a packet-switch-domain with the exiting
circuit-switch-domain. This new introduction did not provide higher data rate
because of jamming of timeslots in the circuit-switch domain. The main aim to
name the new technology to attract the new subscriber but officially 2.5G
system never existed. 2.5G system used some to technology of Third generation
system as like packet switching and have used some of the technology that have
been already used in Second Generation architecture of GSM and CDMA communication.
Global Pocket Radio Service is a 2.5G introduction, introduced by used by GSM
designers. Technologies of EDGE for GSM
and CDMA2000 1xRTT for CDMA, referred to 3G technology cause of the higher data
rate of more than 144 kbps but not quite as 3G technology because original 3G
technology has a way more faster data rate. CDMA2000 without multi-carrier is
the example of 2.75G technology. 2.75G are those systems which partly quality
the 3G technology but not all of the 3G requirements, EDGE system is one of the
example of 2.75G technology. Starting from the year of 1990 lots of 2G systems
has been introduced in the market. Below table 1.2 shows technical perspective
of the different 2G systems.

	GSM	IS-136	IS-95
Year introduced	1990	1991	1993
Access method	TDMA	TDMA	CDMA
Base station transmission band	935 to 960 MHz	869 to 894 MHz	869 to 894 MHz
Mobile station transmission band	890 to 915 MHz	824 to 894 MHz	824 to 849 MHz
Spacing between forward and reverse channels	45 MHz	45 MHz	45 MHz
Channel bandwidth	200 kHz	30 kHz	1250 kHz
Number of duplex channels	125	832	20
Mobile unit maximum power	20 W	3 W	0.2 W
Users per channel	8	3	35
Modulation	GMSK	?/4 DQPSK	QPSK
Carrier bit rate	270.8 kbps	48.6 kbps	9.6 kbps
Speech coder	RPE-LTP	VSELP	QCELP
Speech coding bit rate	13 kbps	8 kbps	8, 4, 2, 1 kbps
Frame size	4.6 ms	40 ms	20 ms
Error control coding	Convolution 1/2 rate	Convolution 1/2 rate	Convolution 1/2 rate forward, 1/3 rate reverse

Table 1.2: Second-Generation Cellular
Telephone Systems.

1.3.3 Third-Generation Systems

Once
various kinds of 2G systems has been marketed, new people started to show their
interest into the cellular communication. Demands of new subscriber for higher
data rate increased. It’s the time to implement new system which will provide
more data rates.

The
primary goal of the Third-generation (3G) mobile communication is to satisfy
more high-speed technology which will higher data rates along with multimedia,
data, and video in addition to voice. International telecommunication Union
defined their outlook of requirements of the 3G cellular communication in the
year of 2000(IMT-2000):

System will assure the same voice quality as PSTN
System will co-op with the data rate of 144 kbps
in terms of high speed moving vehicles in a big density of locations.
System will co-op with data rate of 394 kbps for
object of slowly moving or sitting at the same place in a small location.
System will co-op with the data rate of 2.048
mbps in an indoor office type location.
System will co-op with symmetrical and
asymmetrical data transmission rates
System will co-op for both packet switched and
circuit switched data services
An adaptive interface to the Internet to reflect
efficiently the common asymmetry between inbound and outbound traffic
System will be able to co-op with different bands
of telecommunication accessories.
System will be more flexible to introduce new
services and technologies.

As
of lot can assume that 3G communication is the new version of the 2G system
Actually it’s not true and the uses of the frequency spectrum is not the same
between the 2G and 3G system. Japan was the first country who constructs the
whole system and open up new frequency between the operators to the large
amount of customers in the year of 2005. The first country which introduced 3G
on a large commercial scale was Japan. Forty percent out of the total customer
in Japan subscriber started to use 3G technology by the year of 2005. Operators
are expecting to complete the conversion between 2G system to 3G systems mostly
by the year of 2006 and from conversion of 3G to 3.5 with the transmission of
data 3 Mbps are on the way.

Figure 02 below shows the
substitute way of design method that has been approve as part of IMT-2000.

Figure 1.2: IMT-2000 Terrestrial Radio
Interfaces.

The
requirements wrap a set of radio interfaces for optimized performance in
various radio environments. The main factor of the introduction of five
substitutes was to approve easy expansion from existing first and second
generation systems. The five substitutes show the expansion from the 2G. Two of
the requirements grow out of the work at the European Telecommunications
Standards Institute (ETSI) to establish a UMTS (Universal mobile
telecommunications system) as Europe’s 3G cellular standards. One of these is
known as Wideband CDMA or WCDMA and another one is IMT-TC or TD-CDMA. Another
CDMA-based system, cdma2000, has a North American origin Cdma-2000 is also
developed according to the specification of CDMA is the North American version.
Because of individual chip and technology of multi-carrier on cdma-2000, W-CDMA
differs from cdma-2000. Two other interfaces are IMT-SC is mainly developed for
TDMA-only communication and IMT-FC can be used by both TDMA and FDMA
frequencies to provide some 3G services.

1.3.4 Fourth-Generation Systems

This
latest standard of telecommunication is focused to aggregate and replace the 3G
standard, maybe in recent years. Connect information anywhere, anytime, with a
seamless communication to a broad range of information and services, and
receiving a high structure of information, data, pictures, video, and so on,
are the keys of the 4G communication. The future 4G basis will consist of a set
of broad communication using Internet protocol as a common protocol so that
subscribers are in command because subscriber will be able to select every
application and environment.

According to the progressive
features of cellular system, 4G will have higher bandwidth,

Higher
data rate, and easier and quicker handoff and will focus on seamless
applicability across a multitude of mobile systems and networks. The main focus
is integrating the 4G capabilities with all of the existing mobile technologies
through advanced technologies. Application adaptability and being highly
dynamic are the main features of 4G services of concern to subscribers. These
features mean services can be delivered and be available to various subscribers
and assist the subscriber in moving traffic, air interfaces, radio environment,
and supreme perform of service. Linking to the cellular communication can be
transform into multiple forms and layers correctly and easily. The commanding
method of access to this pool of information will be the cellular telephone,
Personal Digital Assistant, and laptop to seamlessly access the voice
communication, high-speed information services, and multimedia broadcast
services. The 4G will support most systems from different networks, public to
private; company based broadband connection to private areas; and ad hoc
networks. The 4G systems will run with cooperation of with 2G and 3G systems,
as well as with broadband transmission systems. Furthermore, 4G systems will
provide Internet Protocol passed wireless communication. This entire aspect shows
the various range of systems that the 4G defines to satisfy, from satellite
broadband to high distance platform to cellular 3G and 3G systems to wireless
local loop and fixed wireless access to wireless local area network and
personal area network, all with Internet
Protocol as the adapting technique.

Technology	1G	2G	2.5G	3G	4G
Design Began	1970	1980	1985	1990	2000
Implementation	1984	1991	1999	2002	2010
Services	Analog voice, synchronous data to 9.6 kbps	Digital voice, Short messages	Higher capacity, packetized data	Higher capacity, Broadband data up to 2Mbps	Higher capacity, completely IP oriented, multimedia data
Standards	AMPS, TACS, NMT, etc.	TDMA, CDMA, GSM, PDC	GPRS, EDGE, 1xRTT	WCDMA, CDMA2000	OFDM, UWB
Data Bandwidth	1.9 kbps	14.4 kbps	384 kbps	2 Mbps	10 Mbps – 20 Mbps
Multiplexing	FDMA	TDMA, CDMA	TDMA, CDMA	CDMA	FDMA, TDMA, CDMA
Core Network	PSTN	PSTN	PSTN, Packet network	Packet Network	All-IP Networks

Table 1.3: Short history of cellular
communications evolution

1.4
3G Mobile Networks

International
Telecommunication Union (ITU) planned in order to implement a frequency band of
2000MHz globally. The International Mobile Telephone IMT2000 supports technical
analysis for high-speed telephone solutions. The world of wireless
communication development arrives at GSM.IS – 136/PDC AND CDMA. The 3G
evolution for CDMA system brings CDMA2000. THE 3G evolution for GSM, IS-136 and
PDC system leads to Wideband CDMA (W- CDMA), also known as Universal Mobile
Telecommunication Service (UMTS). W-CDMA is based on the network fundamentals
of GSM with the same improvement also implemented in GSM and IS-136 through
EDGE.

Past
communication was mostly depending only on 2G but due to advancement in
technology, there was an introduction of latest technology such as Wireless
Internet Access (Wi-Fi and Video telephony which require universal standards at
higher user bit rates.

2.1
Different Features of third Generation (3G) Technologies

Third
Generation (3G) technology is standard for mobile communication. Different
standards are required to cooperate for working together. The solution is
provided by standardization bodies and promoted to the third Generation
partnership program (3GPP).

The
3GPP consists of the following components

§
The access
Network

The access network depends on the radio interface of
Universal Terrestrial Radio Access (UTRA) which has two
operation modes, Frequency Division Duplex (FDD) and Time Division Duplex
(TDD).

§
The core
Networks

The core network developed for 3GPP is evolved from
the GSM core network with the addition of some new technology like Gateway
Mobile Location Center (GMLC).

3GPP adopted two new approaches in developing new
radio scheme which was based on Wide band CDMA (WCDMA), it provides FDD and TDD
mode of operations, and the realization of the network elements from 2G and
2.5G like Visitor Location Register (VLR), Authentication Unit (AuC), Equipment
register (ER), Home Location Register (HLR), Gateway GPRS Support Node (GGSN)
e.t.c, which resulted into a new mobile technology with upgraded software and
hardware and higher bandwidth usage.

2.2
CDMA2000

CDMA2000
network is able to provide data rates of 144kbps and the voice quality is twice
better than the CDMA one system. The system architecture that makes up the
CDMA2000 is the same as the CDMA one with the fundamental difference of the
introduction of the packet data services. The introduction of data service
meant that Base Transceiver Station (BTS) and Base Station Controller (BSC)
should be upgraded to handle this packet data services. The network of CDMA2000
consists of three major parts which are the Radio access network (RAN), Core
Network (CN) and Mobile Station (MS), the CN can then be further divided into
two parts, one part is that which interacts with the PSTN and the other is
connected to the internet.

Figure 2.1: CDMA2000 architecture

2.3 3G W-CDMA (UMTS)

This technology supports up to
14.0 Mbps data transfer rate, the mobile phone supports 384Kbits/s which is
more than 9.6kbps of a single GSM circuit switched channel. UMTS has a
frequency band of 1885-2025MHz and 2110-2200MHz for uplink and downlink
respectively; it uses a pair of 5MHz channel over W-CDMA.

2.3.1 Protocol and
interfaces

There exist a number of
interfaces in UMTS network with its respective protocol stack, the figure below
shows a basic pattern of protocol stacks which vary from one interface to
another.

Figure 2.2: Model of protocol stacks in
UMTS

The
application layer creates and interprets the UMTS signaling messages and also
manipulate data streams, while the transport layer is responsible for
transferring the data streams from one network component to another. We can
roughly say that in the OSI model the application layer are from 5-7 and
transport layer contains OSI layers 1-4. The three planes for protocol stack
are user plane which carry information from the user such as data packets or
voice, while signaling messages are carried by control plane. The transport
control plane carries internal signaling messages if the data transports using
ATM. In application layer the control plane contains signaling protocols use by
the network elements to communicate with each other. The user plane protocol
manipulates the date, i.e. compression and decompression.

2.3.1.1
Signaling Protocols

The
application layer protocol shows how they operate Radio Resource Controls (RRC)
(which lies between mobile equipment a serving radio network controller SRNC)
figure 2.3 shows the signaling procedure, The SRNC can be used to find mobile
capabilities. In the first step the RRC message is composed by SRNC known as UE
capability enquiry, which is sent to the mobile, the mobile replies with the
capability information that include different parameters that describes its
capabilities. (e. g. maximum data rate, number of data rate stream
simultaneously). It can handle a whether to support or not to support GSM.

The
SRNC replies with conformation in formation. When time expires before receiving
SRNC’s conformation, it retransmits its capability information.

Figure 2.3: Operation of the RRC
Protocol in the UE capability enquiry procedure

The
MAP mobile application part handles signaling communications across different
interfaces in the core network. If a call from the mobile to gateway MSC
arrives, the MAP message will be sent to the HLR by GMSC and will ask for
mobile current location. So it will be able to forward the call to correct MSC.
The radio access network application part (RANAP) and radio network subsystem
application part (RNSAP), Node B application part (NBAP) and radio network
subsystem application part (RNSAP) have similar role in the radio access
network on the Iub, Iu and Iur interfaces respectively.

The
air interface has two levels non access stratum (NAS) and access stratum (AS)
Protocol, which lays in the non access stratum exchange messages between the
core network and the mobile. The four of these are call control (CC) protocol
which runs in the circuit switch domain and the mobile, and manages setup and
tear down data transfer. The mobility management (MM) and the GPRS mobility
management (GMM) protocols handle bookkeeping messages which only effect the
internal operation in the system and not related to any data stream. The RCC
protocol lies in the access stratum and use for exchanging messages between the
radio access network and mobile.

2.3.1.2
Transport Protocols

In
the air interface access stratum, information is transported using unique
protocols to UMTS. The physical layer air interface is most important. The physical
layer is assisted by two layer protocols, the Medium Access Control (MAC)
protocol and Radio Link Control (RLC) protocol. The MAC controls the physical
layer e.g. at a particular time how much data is transmitted to and from the
mobile station. While RLC manages the data link between the radio access
network and the mobile by task. As retransmitting of data packets in case of
incorrect arrival, we can roughly say that the physical layer is implemented in
the Node B and in the mobile. While RLC and MAC are implemented in the mobile
and it’s serving RNC. The circuit switch domains transmit voice calls using
pulse code modulation PCM. This transport mechanism is used in digital fixed
line phone network. The analogue speech signal is digested with 8 bit resolution
at a sample rate of 8 KHz to give 64 Kbps bit rate. The resultant signal is
converted into symbols, then mixed with a carrier and multiplexed with other
PCM signals, before transmission there is no processing lie compression or
error correction. In other parts of the network, the protocols use for data
transportation or Asynchronous Transfer Mode (ATM), internet protocol IP and
Message Transfer Part (MTP) of SS7 protocol stack.

Location

Protocol

Description

CS domain

BICC

ISUP

MEGACO

TUP

Bearer independent call control protocol

ISDN User part

Media Gateway Control Protocol

Telephone User Part

CS and PS domain

BSSAP+

MAP

Base station Subsystem application part plus

Mobile application part

PS domain

GTP-C

GPRS Tunneling protocol control part

UTRAN

NBAP

RANAP

RNSAP

Node B Application part

Radio access network application part

Radio network subsystem application part

Uu non-access stratum

GMM

Call control

GPRS Mobility Management

Session Management

Uu Access Stratum

RRC

Radio resource Control

USIM

Attention commands

TABLE 2.1 : List of signaling protocols
in UMTS, according to their task.

2.3.2
User Plane Control

It
manipulates the data of user interest and carries small number of signaling
messages. In example we take Adaptive Multi Rate (AMR) codec. The voice calls
are transmitted at 64Kbps by circuit switch. For air interface, it is too fast
because Signal to Noise (SNR) ratio is rather low, so low maximum data rate.
The code AMR compresses the information on the path between MSC and mobile work
in a data rate 10

Between
4.7kbps and 212kbps, this increases the number of mobiles in the cell. The ARM
codec is implemented in the core network and mobile compressed information from
using ATM and IP.

Location

Protocol

Description

Service

CS domain

Nb UP

Nb user plane protocol

PS domain

GTP-U

GPRS tunneling protocol user part

GPRS

UTRAN

Iu UP

Iub UP

Iur UP

Iu User plane protocol

Iub User plane protocol

Iur User plane protocol

Uu Non-access

AMR

Adaptive multi rate Codec

Voice

Stratum

RLP

SMS

Radio Link protocol

Short message service protocol

CS Data

SMS

Uu access

BMC

Broadcast multicast control

CBS

Stratum

PDCP

Packet data convergence protocol

GPRS

USAT

USIM application toolkit

Table 2.2 : List of user plane protocols
in UMTS according to the task.

Location

Protocol

Description

CS domain

PCM

Pulse code modulation

CS domain

ALCAP

Access link control application protocol

PS domain

UTRAN

ATM

MTP

Asynchronous transfer mode

Internet Protocol

Message transfer part

Uu access stratum

MAC

PHY

RLC

Medium access control

Air interface physical layer

Radio link control

Table 2.3 : List of transport protocols
in UMTS according to the task.

2.4 Issues of 3G Technology

Although 3G was
successfully introduced to users across the world, some issues are debated by
3G providers and users:

§ Expensive input fees for the 3G service
licenses in some jurisdictions

§ Differences in licensing terms between
states

§ Level of debt incurred by some
telecommunication companies, which makes investment in 3G difficult

§ Cost of 3G phones

§ Lack of coverage in some areas

§ High prices for 3G in some countries

§ Battery life of 3G phones

2.5 Where was 3G spectrum first introduced

Japan was the first country to introduce 3G on a large commercial scale.
In 2005, about 40 per cent of subscribers used only 3G networks. It is expected
that during 2006 the subscribers would move from 2G to 3G and upgrade to the
next 3.5 G level.

The success of 3G in Japan also shows that video telephony was the killer
application for 3G networks. Downloading music was the biggest draw in 3G
services.

There are about 60 3G networks across 25 countries.

For
infrastructure providers 3G will be a value-add during slowdown, as they would
get to put in a lot of new developments. Layout of next generation networks
that are 3G compatible will help in better manageability of services over the networks.
Even service providers believe that 3G would make the entire mobility space
much more accessible. The broadband connection, as they have not reached the
set target, will also benefit with 3G coming to Bangladesh.

3G will help
service providers manage their existing infrastructure better and remain
competitive in a mobile number portability (MNP) regime. It will also generate
a more addressable market to the GSM service providers. They can go back to
their existing customer base and provide them with enhanced data services

3G will not only
make its presence felt in cities and towns but also bring in better and faster
networks to rural Bangladesh.

In the years to
come 3G would make a lot of difference in making business models more
innovative. 3G and WiMax will help solve the problem of low broadband
penetration in Bangladesh to a great extent. It is high time the government
realizes the need and use of 3G. In a fast growing economy these technologies
have the power to change the development roadmap of the country.

2.6 Worldwide 3G Subscribers

Japan is at the vanguard of
3G technology development, network build and commercialization. NTT DoCoMo
launched the world’s first commercial 3G network in late 2001, and while
service providers in 115 other countries have since followed suit, Japan still
lays claim to the largest 3G subscriber base in the world. With almost 92
million UMTS users at the end of March 2009, Japan has 50% more 3G subscribers
than the United States, and three times as many as South Korea.

Figure 2.4: Worldwide 3G subscribers.

Over the next five years all
this will change. While Japan’s progress to date has been impressive, 3G users
now account for 85% of the total wireless subscriber base, which means the
technology now only has a limited pool of late adopters to migrate. Combine
that with a sub-4% annual growth rate across all wireless subscribers, and the
market is close to saturation. This is not the case with any other country.
None even comes close to the current Japanese 3G take-up rate, thus they have
plenty more growth potential.

UMTS and Quality of Service

3.1 UMTS Architecture

Universal
Mobile Telecommunications System (UMTS) is characterized by the development in
terms of various services and bandwidth. The evolution of these networks is
based on the GSM/GPRS networks. UMTS networks support all types of applications
like data, voice and video. While IP is the driving technology, UMTS introduced
a new radio access technology based on radio access network without any major
change to the core network.

Figure 3.1: UMTS model architecture

The
public land mobile network has two major divisions:

§
UMTS Terrestrial
Radio Access Network (UTRAN)

It handles all radio related functionalities.

§
Core Network

It is responsible for maintaining subscriber data and
for switching voice and data connections.

UMTS
architecture physically contains two main domains:

§
User equipment
(UE)

It is the area where users acquire the services of
UMTS

§
Infrastructure
domain (PLMN)

This domain includes the physical nodes responsible
for termination of the interfaces to provide end-to-end service to the user.

Each characterizes a maximum level group of physical
segments

The detailed description of
the UMTS domain architecture is depicted below:

Figure 3.2: UMTS domain architecture

3.2
UMTS Domain

UMTS
domain is classified mainly in two parts.

§ User Equipment Domain

§
Infrastructure
Domain

3.2.1
User Equipment Domain

This
domain contains various mobile terminals and electronic smart card that is removable
as well as portable. This domain is divided into two parts.

§ UMTS Subscriber Identity Module (USIM)

§
Mobile Equipment (ME)

3.2.1.1
UMTS Subscriber Identity Module (USIM)

It
is an electronic smart card that contains the information about the user to
identify in the network. To enable the user in the network the SIM should be
connected in the ME.

3.2.1.2
Mobile Equipment (ME)

It
is the Terminal equipment that the subscriber can access the network by using
this equipment. It is capable both for transmission and reception. It is a sort
of transceiver.

3.2.2
Infrastructure Domain

This
domain is the principle part of the UMTS Architecture. It is classified into
two parts.

§ Access Network domain

§
Core Network
domain

3.2.3
Access Network Domain: It is used to
connect all the nodes with core network. It is as like as gateway to connect
with core network for node-B.

3.2.3.1
Universal Terrestrial Radio Access Network (UTRAN)

The
radio access network of UMTS is called UTRAN/Universal Terrestrial Radio Access
Network, which is responsible for radio resource, data, signaling traffic,
exchange between UE and CN, it also handles with drawl and allocation of radio
bearers required for traffic support and control to some extent UE mobility and
network access technology is based on WCDMA.

UTRAN
is combination of two parts.

§ Radio Network Controller (RNC)

§
Node-B

3.2.3.1.1
Radio Network Controller (RNC)

Radio
Network Controller is control unit of UTRAN, it performs various tasks and
controls all radio resources within RNC, and it is same as BSC in GSM. Most of
protocols between RAN and UE are implemented in the RNC, it communicates over
Iu interface with a maximum of one fixed network nodes SGSN and MSC. Each RNC
is allocated to an SGSN and MSC; it also has an option of using Iur-interface
to communicate over core network CN with neighboring RNC’s.

3.2.3.1.2
Node B

Node
B corresponds to the Base Transceiver Station (BTS) in UMTS. Node B can manage
one or more cells connected to RNC over interface Iub. Node B includes CDMA
receiver which convert the radio interface signal into data stream and then
forward to RNC over Iub interface. The CDMA transmitter prepares incoming data
for transport over radio interface and routes it to power amplifier, and
because of the large distance between the RNC and the Node B time critical
tasks are not stored in RNC. The RNC knows the exact picture of the cell
current situation and makes a sensible decision on power control, handover and
call admission control. The mobile station and Node B continuously measures the
quality of connection and interference level and the result is transmitted to
RNC. Node B, in some cases handles the splitting and combining data streams of
different sectors.

3.2.4
Core Network Domain

The
core network controls the connection when the user initiates or terminates the
call to access Packet Switched (PS) or Circuit Switched (CS) services. The core
network also provides interworking with external networks, it also manages
mobility of the user in a home and visited network, also responsible for
location updating, authentication, control charging and accounting. The core
network of the UMTS is the combination of GSM network subsystem (NSS) and
backbone of GPRS with a complete new radio network (UTRAN). The main difference
between UMTS & GSM is the radio interfaces and access technique. This
domain consists of three parts

§ Home Network Domain

§ Serving Network Domain

§
Transit Network
Domain

3.3
UMTS network interfaces

§ lub: Responsible
for connection between RNC and Node-B

§ lur: This
interface is used to connect two RNCs.

§ Uu: UTRAN
and UE are connected through this interface.

§ Iu: This
inter face help to establish link between RNC and 3G core network.

§ Iu-CS: Circuit
switched domain connects with the RNC using this interface.

3.4
Quality of Service in 3G Network

The
second generation of Global System for Mobile Communications (GSM)/code
division multiple access (CDMA) is necessary for one QoS option , which is
speech transmission at its full rate coding in GSM. Thereafter a half-rate
service and thus introduced a new QoS option. However the effect of this on
communication was to save network capacity, so it can serve more users in
congested hotspots rather than providing a new grade of service to all level of
users. The offer of full or half-rate was never given to the user; subscribers
with half-rate capable mobile phones were put onto half-rate, without the
subscriber knowing that the Quality of speech was deliberately lowered by the
network being used. In the evolution of 2.5G networks e.g. General Packet Radio
Service (GPRS), an attempt was made to introduce mechanism whereby the
subscriber can request a different QoS (throughput, packet delay, e.t.c). From
study, the QoS metrics are established at the beginning of the data transfer
session at the PDP CONTEXT setup. For instance, a user using an interactive
service, might opt for a service with faster reaction time/lower round –trip
delay, that might be suitable for a smaller packet delay at PDP context setup
time, and the network decide if its allowed or denied.

Table 3.1
UMTS QoS requirement

3.5
Benefits of QoS

QoS
enables a network to deliver classes of service (CoS), which means different
classes of treatment are given to different group of services and or group of
users. QoS allocates network capacity according to the type of service while
CoS do the provisioning of the preferred allocation of required network
resources in a way as of DiffServ for IP-based services. CoS is used in QoS
policy associated with the user and also used by the network to provide QoS
treatments to different services. 3GPP end-to-end QoS parameters, which also
include the identification and definition of UMTS architecture, bearer
services, and recommendations for supporting QoS mechanisms, it establishes
four UMTS QoS traffics for mobile and wireless data.

3.6
UMTS QoS Basic Classes

The
following traffic classes are available in UMTS/3GPP

§ Conversational

§ Interactive

§ Streaming

§
Background

Table 3.2 : Qualitative QoS requirements
for different applications

3.6.1
Conversational Class

This
is the class that involves real-time communication e.g. audio, video calls.
Generally the requirements for speech are low delay, low jitter, and clarity
with no reverberation. Failure to meet the basic requirement can result in lack
of quality and unacceptable. Subjective evaluations have shown that the
end-to-end delay has to be less than 400 ms for video and audio conversation.
Video application is another application that will use conversational class for
UMTS transport.

3.6.2
Interactive class

This
class mostly occurs in the internet, it allows smooth interaction of humans and
machines with other devices. Asymmetric type is used and buffering is allowed,
there is no guarantee of bit rate because it uses the best effort service model
while the delay factor is also kept at the minimum, example of applications
using this class are web browsing, server access, and database retrieval, also
is the emerging M-commerce application e.g. wireless auction and online games.

3.6.3
Streaming Class

This
class consists of real-time applications that exchange information between
viewer and listener; all multimedia services are present in this class.
Asymmetric traffic type is used in it and guaranteed bit rate is provided, here
we use the requirement for low jitter and media synchronization such as
Multimedia streaming.

3.6.4
Background Class

This
class includes all applications that either receive data passively or actively
request it, but without any immediate need to handle the data. Email is the
suitable example for this class, the traffic type is asymmetric, buffering is
allowed and high variable delay exists, bit rate does not provide any guarantee
because it relates to the best effort service model.

Radio Network Planning (RNP) and
Capacity Calculation

Radio Network Planning

Overview:

The
objective of radio network planning activity is to estimate the number of sites
required providing coverage and capacity for the targeted service areas and
subscriber forecast. This section describes a methodology that is suitable for
dimensioning and planning of a 3G network based on utilization of the OFDM and
OFDMA PHY of IEEE 802.16.

4.1 Nominal Point Planning using Google
Earth:

Google
Earth displays satellite images of varying resolution of the earth’s surface,
allowing users to see things like cities and houses looking perpendicularly
down or at an oblique angle, with perspective (see also bird’s eye view). The
degree of resolution available is based somewhat on the points of interest and
popularity, but most land (except some islands) is covered in at least 15
meters of resolution. Melbourne, Victoria, Australia; Las Vegas, Nevada; and
Cambridge, Cambridgeshire include examples of the highest resolution, at 15 cm
(6 inches). Google Earth allows users to search for addresses for some
countries, enter coordinates, or simply use the mouse pointer to browse a
location.

We use Google Earth to plan the radio
network for 3G network. The procedures of Radio Network are given below
geographically:

Step 1:

Figure 4.1: Site selection for RNP

At first, we have to select the region
where the plan belongs to set up. For doing this we have to open the Google
Earth software in the computer and using the search bar the desired place can
be found.

Step 2:

Figure 4.2: Area selection for RNP

Now we have to select the coverage area
using ruler. The parameters should be in circle and the distance would be near
about 400 to 500 meters by considering the antenna size and capacity. Here we
take 500 meters for calculation. The yellow colored circle shows the area what
we have selected. Our center point is Daffodil International University, Sukrabad.

Step 3

Figure 4.3: Point selection for BTS
placement

Considering our circle area in step 2,
now we have to place the BTS’s. For doing this we take three (3) different
points by considering the zero (0) degree on North Pole. There are three BTS’s
should be in the cell. The direction of the BTS’s in the cell is on zero (0)
degree, 120 degree and 240 degree. Here we mark the direction of BTS’s by using
Red colored place mark. It should be noted that North Pole should be in zero
degree and this is calculated in anti-clockwise direction.

Step 4:

Figure 4.4: Several points selection for
BTS (3G Network) placement

Following step 3 we take another two
cells for BTS placement. This way we can cover the whole country for 3G network
configuration. Here we have shown only three areas of the planning. The center
points of the BTS’s are the green colored place mark and three BTS’s are placed
on each center point.

Step 5:

Figure 4.5 : Polygon of the perspective
cluster

After taking the cell range in different
areas we have made polygon for divide the areas into regions. There are too
many cells need to take for planning, but we take few cells under a polygon.
Polygon is necessary to operate every cell efficiently.

4.2 Nominal Point Planning using MapInfo:

MapInfo provides location
intelligence solutions through combining software, data (both spatial and non
spatial) and consultancy with project management, systems design and
development, training and support. MapInfo produces a wide range of software
including Spatial Cartridges for databases (Spatial Ware), Routing (Routing J
Server), Geocoding (MapMaker), Site Analysis (Any Site), Risk Analysis, Market
Analysis, Demographic Analysis (TargetPro) and the Envinsa web services suite
along with the more traditional Geographic Information System (GIS) software.
MapInfo’s GIS software products include the desktop GIS software, MapInfo
Professional, MapXtreme 2005 and MapXtreme Java for web-based and desktop
client mapping, as well as developer tools such as MapBasic. The latest version
of MapInfo Professional is v11.0, which was released on 19 June 2011 and now
comes as standard in SCP Software Copy Protection.

MapInfo
provides the Confirm Asset Management product globally to address full life
cycle Asset Management Software and services to the public and civil
engineering sectors. MapInfo provides specific Training, Consulting, Project
Management services for this area.

At first MapInfo Software must be
perfectly installed in the computer and then the software must be run from
program files.

4.2.1 Configuring the Nominal Point
using MapInfo:

Step 1:

Figure 4.6 : Taking the Longitude and
Latitude in .xls format

From Google Earth we save the planned
polygon in .kml format, then open it in excel. From there we take the values of
Longitude, Latitude, Azimuth, Beamwidth and Cell ID in three different angles.

Step 2:

Figure 4.7 : Opening the MapInfo

When MapInfo is opened it appears the quick
start menu. We have to open it as a Table. Now we have to open the .xls file
here from the location where it is located.

Figure 4.8 : Opening
the .xls file from the location

Step 3:

Figure 4.9 : Configuring the Excel
Information Bar

Then on the window the Excel Information
bar is opened. Here we have to mark “Use Row Above Selected Range for Column
Titles and then press the OK button.

Step 4:

Figure 4.10 : Setting up the appropriate
values for variables

After
completing the Excel Information Bar we have to configure the “Set Field
Properties”. Here we set the values in appropriate types. Here the Fields are
Site_Name, Sector_ID, Longitude, Latitude, Azimuth, Beamwidth, Cell_ID and the
Types are Character, Float, Integer. The Site_Name, Sector_ID, Cell_ID is in
Character, Longitude and Latitude is to be in Float, Azimuth,Beamwidth is in
Integer.

Figure 4.11 : .xls file
in MapInfo

Now the Excel file is opened with
MapInfo. Then we find a page named as the configuration. We select three areas
and they are Dhanmondi, Sukrabad and Kalabagan. Every site is divided into
three different angles. The Beam width of the sector is 90.

Step 5:

Figure 4.12 : Using the celltools option
to draw the Sector Symbol

Figure 4.13 : Using the
CellMaker option for drawing the Sector Symbol

Step 6:

Figure 4.14 : Opening
the .TAB file

Using the “CellMaker” tool we have to
configure “Sector Builder” menu. Before doing this we have to select the .TAB
file and set the option Get Sector Designator From in Site_Name. We can also
configure it as Cell_ID, Longitude and Latitude. The window will be same as
below:

Figure 4.15 :
Configuring the Sector Builder Bar

Step 7:

Figure 4.16 : Configuring the style of
the BTSs

In “Sector Builder” menu the parameters
should configure with predicted format. In this menu the options are “Get
latitude from” which should be in “Lat”, “Get longitude from” which should be
in “Long”, “Get sector orientation from” which should be in “Azimuth” and “Get
sector beamwidth from” which should be in “Beamwidth”. The site radius should
be 2500 feet. After continuing the form the plan will be shown with details
with the parameters. The sites map will be like as the below:

Figure 4.17 : Style of
BTSs

Step 8:

Figure 4.18 : Configuring the Layer
Control and Label

By using the “Layer Control” and “Label”
we have to customize the MapInfo at our requirements. The Layer Control gives
the support to configure the output either on Site_Name or Sector_ID or Long or
Lat or Azimuth or Beamwidth or Cell_ID. We can choose one option or we can
choose different options according our requirements. After labeling the window
becomes as the below:

Figure 4.19 : Final
view of the BTS’s placement

4.3 Capacity Calculation for a small
area in 3G

4.3.1 User Distribution in a Cell

Area
of Dhanmondi = 9.74 sq. km

Total number of people in our
selected area = 201,529

Number of mobile user is 1 in
between 6 people.

So, the total Mobile Phone
user in this area = 201,529/6

= 33588.17

In dense urban areas, masts
are commonly spaced 400-800 meter apart [22].

So,

This area requires 12 cells for
the coverage.

Thus, total mobile user in 12
cells is 33588.17

Now, total mobile user in 1
cell = 33588.17/12

So, number of user in a cell
is 2800 (approximately).

Capacity planning in WCDMA
networks is much more complicated than in GSM/EGPRS. Factors that affect the
coverage calculations are load, interference, traffic behaviors, speed of
subscribers etc.

For WCDMA, the total channel
pool can be obtained by taking the number of channels per cell in the equally
loaded case and multiplying that by 1+i,
which then gives the single isolated cell capacity.

4.3.2 Uplink Interference for Each Cell

WCDMA
is an interference system limited by the air interference. Hence, capacity
planning would need to calculate the interference and the cell capacity, i.e.
the amount of traffic that is supported by a base station. The amount of uplink
interference has a great impact on the cell capacity and radius. The
interference margin (?) indicates the total amount of interference (including
thermal noise power) in comparison to the thermal noise:

Where,

E_b/N₀= Signal energy per bit/noise spectrum density=1.5 dB

N = total no. of users per
cell= 2800

R = bit rate=12.2 kbps (fixed
for 3G)
[21]

W = chip rate = 3.84 Mcps

I = other cell to own cell
interference, which is approximately 0.67

V_j= activity
factor for user j = 2.55 (when 3 sectors per cell)

The interference margin, ?_UL=1.5(12.2/3.84)*2800*(1+0.67)*2.55

= 56.42 dB/km

Thus, the cell capacity, N_UL={56.42/(1+0.67)}[1+(3.84/12.2)/1.5*(1/2.55)]

=
36.55

So,
the channel in one cell is 36

Total
channel in all cells is 432

5.1 Conclusions

An
efficient network planning process is a vital aspect of 3G network. Key
differences arise between 2G and 3G networks due to the different levels of
service offered. It is important to identify and analyses the relationships
between capacity and coverage in such networks.

In
this project we have tried to show the process of Radio Network Planning of 3G
network and also done the capacity calculation for a small urban area. For this
purpose we first selected a small area, calculated the coverage and number of
Base stations in our selected area according to the simulation by MapInfo
software. After that we discussed about the capacity planning and calculated
capacity for all cells in our selected area. User’s distribution in a cell and
interfaces for uplink and downlink, with the base of total number of people of
that area is also calculated in capacity planning part.

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Quality of Experience in Next Generation Networks Through Network Selection
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[3] Hua Zhu, Ming Li, I. Chlamtac, and B. Prabhakaran, “A survey
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[4] Dapeng Wu and R. Negi, “Effective capacity: a wireless link
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[5] A. Gurijala and C. Molina, “Defining and monitoring QOS
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[6] O. Ormond, J. Murphy, and G.-M. Muntean, “Utility-based
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[7] D. Niyato and E. Hossain, “call admission for QoS provisioning
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11 , Sept.-Oct. 2005.

[8] Lars Staalhagen, “Introduction to OPNET Modeler,” Aug
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[9] M.Li, R.Cuny, D.Soldani, QoS and QoE Management in UMTS Cellular
Systems

.: John Wiley & Sons, Ltd, 2006.

[10] T. Guenkova-Luy, A.J. Kassler, and D. Mandato, “End-to-end
quality-of-service coordination for mobile multimedia applications,” vol.
22, no. 5, pp. 889 – 903 , June 2004.

[11] Ruijun Feng and Junde Song, “Some QoS issues in 3G Wireless
Networks,” vol. 2, pp. 724 – 727 , Oct 2002.

[12] Gwo-Chuan Lee, Long-Sheng Li, and Wei-Yu Chien,
“Heterogeneous RSVP Extension for End-to-End QoS Support in UMTS/WLAN
Interworking Systems,” pp. 170 – 175 , Dec 2006.

[13] S.Orial and A.Ramon, P.R Jordi, Radio Resource management
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.: John Wiley & Sons, Ltd , 2005.

[14] ETSI. (2010,
March) Universal Mobile Telecommunications System (UMTS) Network
architecture.[Online].

http://www.etsi.org/deliver/etsi_ts/123000_123099/123002/04.03.00_60/ts_123002v040300p.pdf

[15] Lisimachos Kondi,
Ajay Luthra, Song Ci Haohong Wang,

4G Wireless Video
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[16] Ian Poole, Cellular
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[17] Theodore S.
Rappaport, Wireless Communications: Principles and Practice, 2nd ed.: Prentice
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[18] encyclopedia.
[Online]. http://en.wikipedia.org/wiki/Umts

[19] Theodore S.
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http://www.qualcomm.com/media/documents/files/air-interface-cell-capacity-wcdma-systems.pdf

[21] Vijay K. Garg,
“Wireless Communications and Networking”. Page – (626-627).

[22] http://en.wikipedia.org/wiki/Cell_site

[23] Nishit Narang
Sumit Kasera, 3G networks: architecture, protocols and procedures

.: McGraw Hill, 2005.

[24] R.O. LaMaire, A.
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[25] Christopher Cox, “Essential
of UMTS”, 1st ed., 2008.

Overview of Cellular Network

View With Charts And Images

1. Introduction

1.1 Motivation

1.2 Evolution of Cellular
Communications

Figure 1.1: Evolution of communications
systems.

1.3 Cellular Communications Review

Practicability,
History over the last few decades shows that standards of the wireless
communication have been changed in every decade. In the current decade we
are at the end stage of the 3G standardization phase and opening stage of
the deployment of 3G.

To employ the
subscriber demand of the 21^st century it’s not the luxury that
to have multimedia high data rates in the 3G system but necessity to have
3G goals. Many of the 3G problems have not solved in the 3G but to intend
to solve in the 4G system.

1.3.1 First-Generation Systems

Band of base station	869 to 894 MHz
Band for Mobile Unit	824 to 849 MHz
Forward channels and reverse channels spacing	45 MHz
Channel bandwidth	30 KHz
Size of full-duplex voice channels	790
Size of full-duplex control channels	42
Mobile unit maximum power	3 watts
Cell size, radius	2 to 20 km
Modulation, voice channel	FM, 12-KHz peak deviation
Modulation, control channel	FSK, 8-KHz peak deviation
Data transmission rate	10 kbps
Error control coding	BCH (48, 36, 5) and (40,28, 5)

Table 1.1: AMPS Parameters.

1.3.2 Second-Generation Systems

	GSM	IS-136	IS-95
Year introduced	1990	1991	1993
Access method	TDMA	TDMA	CDMA
Base station transmission band	935 to 960 MHz	869 to 894 MHz	869 to 894 MHz
Mobile station transmission band	890 to 915 MHz	824 to 894 MHz	824 to 849 MHz
Spacing between forward and reverse channels	45 MHz	45 MHz	45 MHz
Channel bandwidth	200 kHz	30 kHz	1250 kHz
Number of duplex channels	125	832	20
Mobile unit maximum power	20 W	3 W	0.2 W
Users per channel	8	3	35
Modulation	GMSK	?/4 DQPSK	QPSK
Carrier bit rate	270.8 kbps	48.6 kbps	9.6 kbps
Speech coder	RPE-LTP	VSELP	QCELP
Speech coding bit rate	13 kbps	8 kbps	8, 4, 2, 1 kbps
Frame size	4.6 ms	40 ms	20 ms
Error control coding	Convolution 1/2 rate	Convolution 1/2 rate	Convolution 1/2 rate forward, 1/3 rate reverse

Table 1.2: Second-Generation Cellular
Telephone Systems.

1.3.3 Third-Generation Systems

System will assure the same voice quality as PSTN

System will co-op with the data rate of 144 kbps
in terms of high speed moving vehicles in a big density of locations.

System will co-op with data rate of 394 kbps for
object of slowly moving or sitting at the same place in a small location.

System will co-op with the data rate of 2.048
mbps in an indoor office type location.

System will co-op with symmetrical and
asymmetrical data transmission rates

System will co-op for both packet switched and
circuit switched data services

An adaptive interface to the Internet to reflect
efficiently the common asymmetry between inbound and outbound traffic

System will be able to co-op with different bands
of telecommunication accessories.

System will be more flexible to introduce new
services and technologies.

Figure 02 below shows the
substitute way of design method that has been approve as part of IMT-2000.

Figure 1.2: IMT-2000 Terrestrial Radio
Interfaces.

1.3.4 Fourth-Generation Systems

According to the progressive
features of cellular system, 4G will have higher bandwidth,

Technology	1G	2G	2.5G	3G	4G
Design Began	1970	1980	1985	1990	2000
Implementation	1984	1991	1999	2002	2010
Services	Analog voice, synchronous data to 9.6 kbps	Digital voice, Short messages	Higher capacity, packetized data	Higher capacity, Broadband data up to 2Mbps	Higher capacity, completely IP oriented, multimedia data
Standards	AMPS, TACS, NMT, etc.	TDMA, CDMA, GSM, PDC	GPRS, EDGE, 1xRTT	WCDMA, CDMA2000	OFDM, UWB
Data Bandwidth	1.9 kbps	14.4 kbps	384 kbps	2 Mbps	10 Mbps – 20 Mbps
Multiplexing	FDMA	TDMA, CDMA	TDMA, CDMA	CDMA	FDMA, TDMA, CDMA
Core Network	PSTN	PSTN	PSTN, Packet network	Packet Network	All-IP Networks

Table 1.3: Short history of cellular
communications evolution

1.4
3G Mobile Networks

International
Telecommunication Union (ITU) planned in order to implement a frequency band of
2000MHz globally. The International Mobile Telephone IMT2000 supports technical
analysis for high-speed telephone solutions. The world of wireless communication
development arrives at GSM.IS – 136/PDC AND CDMA. The 3G evolution for CDMA
system brings CDMA2000. THE 3G evolution for GSM, IS-136 and PDC system leads
to Wideband CDMA (W- CDMA), also known as Universal Mobile Telecommunication
Service (UMTS). W-CDMA is based on the network fundamentals of GSM with the
same improvement also implemented in GSM and IS-136 through EDGE.

2.1
Different Features of third Generation (3G) Technologies

The
3GPP consists of the following components

§
The access
Network

The access network depends on the radio interface of
Universal Terrestrial Radio Access (UTRA) which has two
operation modes, Frequency Division Duplex (FDD) and Time Division Duplex
(TDD).

§
The core
Networks

The core network developed for 3GPP is evolved from
the GSM core network with the addition of some new technology like Gateway
Mobile Location Center (GMLC).

2.2
CDMA2000

Figure 2.1: CDMA2000 architecture

2.3 3G W-CDMA (UMTS)

2.3.1 Protocol and
interfaces

There exist a number of
interfaces in UMTS network with its respective protocol stack, the figure below
shows a basic pattern of protocol stacks which vary from one interface to
another.

Figure 2.2: Model of protocol stacks in
UMTS

2.3.1.1
Signaling Protocols

The
SRNC replies with conformation in formation. When time expires before receiving
SRNC’s conformation, it retransmits its capability information.

Figure 2.3: Operation of the RRC
Protocol in the UE capability enquiry procedure

2.3.1.2
Transport Protocols

In
the air interface access stratum, information is transported using unique
protocols to UMTS. The physical layer air interface is most important. The
physical layer is assisted by two layer protocols, the Medium Access Control
(MAC) protocol and Radio Link Control (RLC) protocol. The MAC controls the
physical layer e.g. at a particular time how much data is transmitted to and
from the mobile station. While RLC manages the data link between the radio
access network and the mobile by task. As retransmitting of data packets in
case of incorrect arrival, we can roughly say that the physical layer is
implemented in the Node B and in the mobile. While RLC and MAC are implemented
in the mobile and it’s serving RNC. The circuit switch domains transmit voice
calls using pulse code modulation PCM. This transport mechanism is used in
digital fixed line phone network. The analogue speech signal is digested with 8
bit resolution at a sample rate of 8 KHz to give 64 Kbps bit rate. The
resultant signal is converted into symbols, then mixed with a carrier and
multiplexed with other PCM signals, before transmission there is no processing
lie compression or error correction. In other parts of the network, the
protocols use for data transportation or Asynchronous Transfer Mode (ATM),
internet protocol IP and Message Transfer Part (MTP) of SS7 protocol stack.

Location

Protocol

Description

CS domain

BICC

ISUP

MEGACO

TUP

Bearer independent call control protocol

ISDN User part

Media Gateway Control Protocol

Telephone User Part

CS and PS domain

BSSAP+

MAP

Base station Subsystem application part plus

Mobile application part

PS domain

GTP-C

GPRS Tunneling protocol control part

UTRAN

NBAP

RANAP

RNSAP

Node B Application part

Radio access network application part

Radio network subsystem application part

Uu non-access stratum

GMM

Call control

GPRS Mobility Management

Session Management

Uu Access Stratum

RRC

Radio resource Control

USIM

Attention commands

TABLE 2.1 : List of signaling protocols
in UMTS, according to their task.

2.3.2
User Plane Control

Between
4.7kbps and 212kbps, this increases the number of mobiles in the cell. The ARM
codec is implemented in the core network and mobile compressed information from
using ATM and IP.

Location

Protocol

Description

Service

CS domain

Nb UP

Nb user plane protocol

PS domain

GTP-U

GPRS tunneling protocol user part

GPRS

UTRAN

Iu UP

Iub UP

Iur UP

Iu User plane protocol

Iub User plane protocol

Iur User plane protocol

Uu Non-access

AMR

Adaptive multi rate Codec

Voice

Stratum

RLP

SMS

Radio Link protocol

Short message service protocol

CS Data

SMS

Uu access

BMC

Broadcast multicast control

CBS

Stratum

PDCP

Packet data convergence protocol

GPRS

USAT

USIM application toolkit

Table 2.2 : List of user plane protocols
in UMTS according to the task.

Location

Protocol

Description

CS domain

PCM

Pulse code modulation

CS domain

ALCAP

Access link control application protocol

PS domain

UTRAN

ATM

MTP

Asynchronous transfer mode

Internet Protocol

Message transfer part

Uu access stratum

MAC

PHY

RLC

Medium access control

Air interface physical layer

Radio link control

Table 2.3 : List of transport protocols
in UMTS according to the task.

2.4 Issues of 3G Technology

Although 3G was
successfully introduced to users across the world, some issues are debated by
3G providers and users:

§ Expensive input fees for the 3G service
licenses in some jurisdictions

§ Differences in licensing terms between
states

§ Level of debt incurred by some
telecommunication companies, which makes investment in 3G difficult

§ Cost of 3G phones

§ Lack of coverage in some areas

§ High prices for 3G in some countries

§ Battery life of 3G phones

2.5 Where was 3G spectrum first introduced

The success of 3G in Japan also shows that video telephony was the killer
application for 3G networks. Downloading music was the biggest draw in 3G
services.

There are about 60 3G networks across 25 countries.

For
infrastructure providers 3G will be a value-add during slowdown, as they would
get to put in a lot of new developments. Layout of next generation networks
that are 3G compatible will help in better manageability of services over the
networks. Even service providers believe that 3G would make the entire mobility
space much more accessible. The broadband connection, as they have not reached
the set target, will also benefit with 3G coming to Bangladesh.

3G will not only
make its presence felt in cities and towns but also bring in better and faster
networks to rural Bangladesh.

In the years to
come 3G would make a lot of difference in making business models more innovative.
3G and WiMax will help solve the problem of low broadband penetration in
Bangladesh to a great extent. It is high time the government realizes the need
and use of 3G. In a fast growing economy these technologies have the power to
change the development roadmap of the country.

2.6 Worldwide 3G Subscribers

Figure 2.4: Worldwide 3G subscribers.

UMTS and Quality of Service

3.1 UMTS Architecture

Figure 3.1: UMTS model architecture

The
public land mobile network has two major divisions:

§
UMTS Terrestrial
Radio Access Network (UTRAN)

It handles all radio related functionalities.

§
Core Network

It is responsible for maintaining subscriber data and
for switching voice and data connections.

UMTS
architecture physically contains two main domains:

§
User equipment
(UE)

It is the area where users acquire the services of
UMTS

§
Infrastructure
domain (PLMN)

This domain includes the physical nodes responsible
for termination of the interfaces to provide end-to-end service to the user.

Each characterizes a maximum level group of physical
segments

The detailed description of
the UMTS domain architecture is depicted below:

Figure 3.2: UMTS domain architecture

3.2
UMTS Domain

UMTS
domain is classified mainly in two parts.

§ User Equipment Domain

§
Infrastructure
Domain

3.2.1
User Equipment Domain

This
domain contains various mobile terminals and electronic smart card that is
removable as well as portable. This domain is divided into two parts.

§ UMTS Subscriber Identity Module (USIM)

§
Mobile Equipment (ME)

3.2.1.1
UMTS Subscriber Identity Module (USIM)

It
is an electronic smart card that contains the information about the user to
identify in the network. To enable the user in the network the SIM should be
connected in the ME.

3.2.1.2
Mobile Equipment (ME)

It
is the Terminal equipment that the subscriber can access the network by using
this equipment. It is capable both for transmission and reception. It is a sort
of transceiver.

3.2.2
Infrastructure Domain

This
domain is the principle part of the UMTS Architecture. It is classified into
two parts.

§ Access Network domain

§
Core Network
domain

3.2.3
Access Network Domain: It is used to
connect all the nodes with core network. It is as like as gateway to connect
with core network for node-B.

3.2.3.1
Universal Terrestrial Radio Access Network (UTRAN)

UTRAN
is combination of two parts.

§ Radio Network Controller (RNC)

§
Node-B

3.2.3.1.1
Radio Network Controller (RNC)

3.2.3.1.2
Node B

Node
B corresponds to the Base Transceiver Station (BTS) in UMTS. Node B can manage
one or more cells connected to RNC over interface Iub. Node B includes CDMA
receiver which convert the radio interface signal into data stream and then
forward to RNC over Iub interface. The CDMA transmitter prepares incoming data
for transport over radio interface and routes it to power amplifier, and because
of the large distance between the RNC and the Node B time critical tasks are
not stored in RNC. The RNC knows the exact picture of the cell current
situation and makes a sensible decision on power control, handover and call
admission control. The mobile station and Node B continuously measures the
quality of connection and interference level and the result is transmitted to
RNC. Node B, in some cases handles the splitting and combining data streams of
different sectors.

3.2.4
Core Network Domain

§ Home Network Domain

§ Serving Network Domain

§
Transit Network
Domain

3.3
UMTS network interfaces

§ lub: Responsible
for connection between RNC and Node-B

§ lur: This
interface is used to connect two RNCs.

§ Uu: UTRAN
and UE are connected through this interface.

§ Iu: This
inter face help to establish link between RNC and 3G core network.

§ Iu-CS: Circuit
switched domain connects with the RNC using this interface.

3.4
Quality of Service in 3G Network

Table 3.1
UMTS QoS requirement

3.5
Benefits of QoS

QoS
enables a network to deliver classes of service (CoS), which means different
classes of treatment are given to different group of services and or group of
users. QoS allocates network capacity according to the type of service while
CoS do the provisioning of the preferred allocation of required network
resources in a way as of DiffServ for IP-based services. CoS is used in QoS policy
associated with the user and also used by the network to provide QoS treatments
to different services. 3GPP end-to-end QoS parameters, which also include the
identification and definition of UMTS architecture, bearer services, and
recommendations for supporting QoS mechanisms, it establishes four UMTS QoS
traffics for mobile and wireless data.

3.6
UMTS QoS Basic Classes

The
following traffic classes are available in UMTS/3GPP

§ Conversational

§ Interactive

§ Streaming

§
Background

Table 3.2 : Qualitative QoS requirements
for different applications

3.6.1
Conversational Class

3.6.2
Interactive class

3.6.3
Streaming Class

3.6.4
Background Class

Radio Network Planning (RNP) and
Capacity Calculation

Radio Network Planning

Overview:

4.1 Nominal Point Planning using Google
Earth:

We use Google Earth to plan the radio
network for 3G network. The procedures of Radio Network are given below
geographically:

Step 1:

Figure 4.1: Site selection for RNP

Step 2:

Figure 4.2: Area selection for RNP

Step 3

Figure 4.3: Point selection for BTS
placement

Step 4:

Figure 4.4: Several points selection for
BTS (3G Network) placement

Step 5:

Figure 4.5 : Polygon of the perspective
cluster

4.2 Nominal Point Planning using MapInfo:

At first MapInfo Software must be
perfectly installed in the computer and then the software must be run from
program files.

4.2.1 Configuring the Nominal Point
using MapInfo:

Step 1:

Figure 4.6 : Taking the Longitude and
Latitude in .xls format

Step 2:

Figure 4.7 : Opening the MapInfo

When MapInfo is opened it appears the quick
start menu. We have to open it as a Table. Now we have to open the .xls file
here from the location where it is located.

Figure 4.8 : Opening
the .xls file from the location

Step 3:

Figure 4.9 : Configuring the Excel
Information Bar

Then on the window the Excel Information
bar is opened. Here we have to mark “Use Row Above Selected Range for Column
Titles and then press the OK button.

Step 4:

Figure 4.10 : Setting up the appropriate
values for variables

Figure 4.11 : .xls file
in MapInfo

Step 5:

Figure 4.12 : Using the celltools option
to draw the Sector Symbol

Figure 4.13 : Using the
CellMaker option for drawing the Sector Symbol

Step 6:

Figure 4.14 : Opening
the .TAB file

Figure 4.15 : Configuring
the Sector Builder Bar

Step 7:

Figure 4.16 : Configuring the style of
the BTSs

Figure 4.17 : Style of
BTSs

Step 8:

Figure 4.18 : Configuring the Layer
Control and Label

Figure 4.19 : Final
view of the BTS’s placement

4.3 Capacity Calculation for a small
area in 3G

4.3.1 User Distribution in a Cell

Area
of Dhanmondi = 9.74 sq. km

Total number of people in our
selected area = 201,529

Number of mobile user is 1 in
between 6 people.

So, the total Mobile Phone
user in this area = 201,529/6

= 33588.17

In dense urban areas, masts
are commonly spaced 400-800 meter apart [22].

So,

This area requires 12 cells for
the coverage.

Thus, total mobile user in 12
cells is 33588.17

Now, total mobile user in 1
cell = 33588.17/12

So, number of user in a cell
is 2800 (approximately).

Capacity planning in WCDMA
networks is much more complicated than in GSM/EGPRS. Factors that affect the
coverage calculations are load, interference, traffic behaviors, speed of
subscribers etc.

For WCDMA, the total channel
pool can be obtained by taking the number of channels per cell in the equally
loaded case and multiplying that by 1+i,
which then gives the single isolated cell capacity.

4.3.2 Uplink Interference for Each Cell

Where,

E_b/N₀= Signal energy per bit/noise spectrum density=1.5 dB