Innovation and Knowledge Management in Business Globalization: Theory & Practice 760

Measuring the Optimal Transmission Power of GSM Cellular Network:
A Case Study

Dr. Basil M. Kasasbeh, Applied Science University, Amman, Jordan, b_kasasbeh@asu.edu.jo
Dr. Muzhir S. Al-Ani, Amman Arab University, Amman, Jordan, muzhir@aau.edu.jo
Dr. Rafa E. Al-Qutaish, Applied Science University, Amman, Jordan, rafa@rafa-elayyan.net
Dr. Khalid T. Al-Sarayreh, Applied Science University, Amman, Jordan, khalid_sar@yahoo.com

Abstract
Mobility management is a leading factor in
personal communications services networks. Thus,
it is important to verify that the mobile unit
receives all services whenever moving from one
place to another. This paper deals with the study
and analysis of the optimal transmission power at a
specific zone through a GSM cellular network. The
definition of coverage area is constructed by a
proper analysis of signal strength measurement.
Some problematic tasks appear through the
variation of geographical terrain. An accurate
coverage area obtained due to an effective cellular
positioning method that not requires any
significant changes to the network or mobile
device.

1. Introduction
The popularity of mobile phones and the number of
device users is continuously increasing that leads
the manufacturers to introduce new services,
features, and technologies. The simplicity, wide
distribution, personality, privacy, trusts all these
features are important in everyday life to support a
huge investment and development in Personal
Communications (PCs). Nowadays, an explosive
increase in the use of mobile devices exists, such as
cell phones, personal digital assistance, global
positioning systems etc.

The rapid growth of mobile networks infrastructure
leads to activate specific rules to control their huge
extension and side effects. Most currently
communication networks are able to perform
power control measurements for the
uplink/downlink. These devices introduce new
features to access with Internet and Intranet. The
main feature of mobile phone lead customers to
access various services any time any location.

Cellular phones offer elegant features such as, bi-
directional information flow, the network to take
the mobility of the users; all calls can originate
from either the network or the user, and high
mobility of user. The basic cellular system allows
the mobile user to connect to the Base Station (BS),
which is connected to the Mobile Switching Center
(MSC) then to the public telephone system. The
biggest treasure that seemed to lie in the further
development of cellular systems, establishing the
third generation (3G), after digital systems (2G),
and analog systems (1G) [1].

The successful of wireless systems is occurred due to
the development of widely accepted standards
especially for cellular communications. These
standards ensure that the same type of equipment can
be used all over the world, and also for different
operations of wireless network within the country.
Digital mobile systems offer a variety of services in
addition to regular phone calls. Although providing
those services is not a big effort for the network
provider, they were a major motivation for customers
to switch from analog mobile systems to other digital
systems. Different applications of wireless systems
have different requirements in terms of data rate,
range & number of users, allowed mobility to the
users, energy consumption …etc. Location-based
services offer a huge number of possibilities for the
definition of new services for the digital wireless
networks. 3G mobile communication systems are
designed to support wideband services of high bit
rate and high quality of services [2].

The rest of this paper is organized as follow: section
2 illustrates the mobile phone infrastructure. Section
3 deals with the details of the location management
in the 3G mobile communication systems. In section
4, the measurement selection has been discussed.
Section 5 presents the measurement analysis and
results, and finally, section 6 concludes the paper.

2. Mobile Phone Infrastructure
The fixed infrastructure of mobile phone networks
includes Base Station (BS) distributed throughout the
intended coverage area of the network. Mobility
management is very important in Personal
Communications Services (PCS) networks. In digital
cellular networks, the two-tier mobility databases,
Home Location Register (HLR), and Visitor
Location Register (VLR), are utilized to support
Visited Network Visited Network
HLR HLR
GLR
VLR VLR
GLR
VLR VLR
Home Network Home Network

Innovation and Knowledge Management in Business Globalization: Theory & Practice 761
mobility management for Mobile Terminals (MTs)
[3]. Fig. 1 illustrates the mobility database
architecture.

Fig 1. Mobility Database Architecture
The services area is partitioned into Location areas
(LAs), and within each LA, there are a number of
cells. All BSs within on LA are connected to a
Mobile Switching Center (MSC). All the MSCs are
finally connected to the Public Switching
Telephone Network (PSTN). Each LA is associated
to a VLR, which is used to store the temporary
records of MT's profiles and location information.
HLR is used to record mobile user's permanent
subscription information. The Gateway Location
Register (GLR) is a node between VLR, Serving
GPRS Support Node (SGSN), and the HLR [4].

The mobile phone cells are sectored around a
common antenna tower. The tower will have several
directional antennas, each covering a particular area,
this called cell-site or Base Transceiver Station
(BTS). All BTSs produce a Broadcast Channel
(BCH) that works continuously. All mobile receive
the BCH signal in order to: allow mobiles to find the
network, allow the network to identify the closet
BTS, identify the coded information, and to accept
different information. Fig. 2 shows the Architecture
of digital mobile system.

Fig 2. Architecture of the Digital Mobile System

3. Location Management in 3G
There are two basic operations in location
management, location update and paging. Location
update is a process through which a system keeps
track of the location of mobile terminals that are
not in conversations. Paging is a search process
conducted in the Paging Area (PA) that may
include one or more cells. Basically there are two
categories of location management, static schemes
and dynamic schemes. In a static, location update
scheme with two-tier mobility database, the HLR
location update are performed when an MT enters
an LA on the PA is the same as the LA. PA size is
fixed but, there are basically three kinds of
dynamic location update schemes in which the PA
size is variable: movement-based location update,
distance-based location update, and time-base
location update [6].

There are three kinds of location updates in 3G
cellular networks: HLR location updates, GLR
location updates, and VLR location updates.
Location updates and paging procedures will cause a
significant amount of cost such as wireless
bandwidth and processing power at the MTs, the
BSs, and mobility database. In both dynamic and
static schemes for 3G, the service area is partitioned
into Gateway Location Areas (G-Las), which is
further partitioned into LAs. A LA consists of a
group of cells. An HLR location update is performed
when an MT crosses a boundary of a G-LA. A GLR
location update is performed when an MT crosses a
boundary of an LA [5].
BTS
BTS
BTS
BSC
BSS
BTS
BTS
BTS
BSC
BSS
ADC NMC
OMC OMC
MSC
MSC
VLR
VLR
EIR
AUC
HLR
.
.
.
.
.
OSI
Interface to
other networks Um-Interface Abis-Interface A-Interface
OMC

Innovation and Knowledge Management in Business Globalization: Theory & Practice 762

4. Measurement Selection
It is important to select the perfect measurement to
reach a specific goal. Manufacturers and Engineers
of mobile phone networks must compensate many
other factors with coverage area measurement. It is
difficult to refer a certain measurement for a
specific point but measures must be chosen for
each requirement. Measurements must be chosen
corresponding to need in each stage of
development, manufacturing, installation and
maintenance.
Phase and frequency error measurements are very
important in BTS, in order to compensate shifts
between transmissions and to avoid interference
with other users. This type of measurements can be
applied when calibration process performed.
Output power is a fundamental transmitter
characteristic, and in mobile phone system it is
important to maintain sufficient power.

This fact leads to minimize the overall system
interference and maximize the battery life. Power
measurements are normally performed in every
phase of BTS lifecycle, such as accuracy, linearity
and repeatability. For some applications it is
sufficient to determine roughly the mobile cell
terminal, but other services require an accurate
system for location measurements.

5. Measurement Analysis and Results
The measurements are applied over the area of the
Applied Science University in Jordan. This area is
divided into four sections according to the
geographical terrain (see Fig. 3, Sections 1, 2, 3 and
4).

The results of the measurement indicate the
distributed of power due to the university is mainly
covered by the cells 25512 (63A8), 25083 (61FB),
25402 (633A) and 25081 (61F9), see Fig. 3 for the
actual cell division.

Fig 3. Actual Cell Division

Section1 represents the area from main gate to the
registration building and down to the cafeteria.
This section distinguishes with flat area and
situated near to the BTS. The dominant cell is
25512 (63A8) with some overlapping with cells
25081 (61F8) and 25083 (61FB). The power
measurements (see Fig. 4a) demonstrate a smooth
distribution of power in this area.

Section2 represents the area from the registration
building to the border of the university. This
section is declined slowly and goes far from the
BTS. The dominant cells are 25512 (63A8) and
25081 (61F9) with some coverage of cells 25083
(61FB) and 25533 (6291). The power measurements
(see Fig. 4b) demonstrate that there is some
fluctuation in the power distributed due to the
variations of the geographical terrain.

Section3 represents the area occupied by the medical
science college to the end of the buses parking. The
dominant cell is 25081 (61F9) and some coverage by
cell 25211 (627B). The power measurements (see
Fig. 4c) demonstrate that this section can be
Section 4
Section 1

Innovation and Knowledge Management in Business Globalization: Theory & Practice 763
subdivided into three parts. First part includes the
area around the medical science building that
indicates a good signal level. Second part includes
the area around the library building that indicates
an accepted level of signal with some effects of far
distance from BTS. Third part includes the area
bounded by buses parking which indicates a high
power level with the effect of flatness area.

Section4 represents the area from the main gate to
the secondary gate which is subdivided into two
parts depending on the power distributed (see Fig.
4d). First part includes the cars parking area that
receive a high level of signal strength due to
flatness and near to the BTS. The dominant cell is
25083 (61FB) with small effects of other cells.

Second part includes the main gate to the
secondary gate which is inclined area, so the signal
strength is fluctuated from high level near the main
gate and decreases down to the secondary gate. The
dominant cell is 25512 (63A8) and some coverage of
the cell 25081 (61F9).


6. Conclusion
This work deals with the power measurements
through a selected area which is divided into subparts
according to the geographical terrain. Through the
measurements of signal strength, we can track the
coverage area and simulate the boundaries of the
effective cell. The signal level through the selected
area is measured within the range -38dBm to -
100dBm. The signal drop (which indicated in some
areas) depends on some factors such as, internal
losses, weather, geographical area, distance from
BTS, and also there are some effective drop denoted
through buildings due to different types of materials.

Innovation and Knowledge Management in Business Globalization: Theory & Practice 764
Fig 4. Distribution of Power in all Sections

7. References
[1] Chen, Y.; Sirer, E. G. and Wicker, S. B. “On
Selection of Optimal Transmission Power for
Ad hoc Networks”, in Proceedings of the 36th
Hawaii International Conference on System
Sciences (HICSS’36), Big Island, Hawaii, USA,
2003.

Innovation and Knowledge Management in Business Globalization: Theory & Practice 765
[2] Molisch, F. Wireless Communications, John
Wiley & Sons, England, 2005.

[3] Ng, K. and Chan, H. W. “Enhanced Distance-
Based Location Management of Mobile
Communication Systems Using a Cell
Coordinates Approach”, IEEE Transactions on
Mobile Computing, Vol. 4, No.1, 2005, pp. 41-
55.

[4] Wu, Jie and Dai, F. “Efficient Broadcasting
with Guaranteed Coverage in Mobile Ad-hoc
Networks”, IEEE Transactions on Mobile
Computing, Vol.4, No.3, 2005, pp. 259-270.

[5] Xiao, Y.; Pan, Y. and Li, J. “Design and Analysis
of Location Management for 3G Cellular
Networks”, IEEE Transactions on Parallel and
Distributed Systems, Vol.15, No.4, 2004, pp. 339-
349.
[6] Zaidi, Z. R. and Mark, B. L. “Real-Time Mobility
Tracking Algorithms for Cellular Networks
Based on Kalman Filtering”, IEEE Transactions
on Mobile Computing, Vol.4, No.2, 2005, pp.
195--208.