Today, in metro cities BTSs are increasing day by day and interference is also increasing. This paper shows the received power of the cell depends on a number of factors. Antenna gain and antenna type are one of the important parameters for this. This paper reveals the effect of signal received power by changing the antenna gain and antenna type.The antenna used is omnidirectional and switched beam and gain varies from 5 to 15 dB.The GSM network is simulated for 6 users in Qualnet software.

1. Int. Journal of Electrical & Electronics Engg. Vol. 2, Spl. Issue 1 (2015) e-ISSN: 1694-2310 | p-ISSN: 1694-2426
NITTTR, Chandigarh EDIT -2015 22
Performance Analysis of GSM Network for
Different Types of Antennas
Mandeep Singh, Supreet kaur
Department of ECE, Punjabi University, Patiala, India
Abstract: Today, in metro cities BTSs are increasing day by
day and interference is also increasing. This paper shows the
received power of the cell depends on a number of factors.
Antenna gain and antenna type are one of the important
parameters for this. This paper reveals the effect of signal
received power by changing the antenna gain and antenna
type.The antenna used is omnidirectional and switched beam
and gain varies from 5 to 15 dB.The GSM network is
simulated for 6 users in Qualnet software.
Keyword:Antenna gain, GSM, omnidirectional antenna, switched
beam antenna, Qualnet Software.
I. INTRODUCTION
The GSM system for mobile communications is a digital
cellular communication system. The GSM is the most
widely used technology used in the world today. During
the early 1980s, analog cellular telephone system
experienced a very rapid growth in Europe. GSM system is
based on the digital technology, which has many
advantages over analog technology. It also provides the
technology as roaming, SMS, fax mail.
Table 1. GSM specifications
Multiple access technology FDMA/TDMA
Duplex technique FDD
Uplink frequency band 890-915 MHz
Downlink frequency band 935-960 MHz
Channel spacing 200 KHz
Modulation GMSK
Speech coding Various originals were RPE-
LTP/13
Speech channel per RF channel 8
Channel data rate 270.833 kbps
Frame duration 4.615 ms
The GSM cellular technology uses 200 KHz RF channels.
These are time division multiplexed to enable up to eight
users to access each carrier. In this way it is a
TDMA/FDMA. The core of any radio based system is
format of the radio signal itself. The carrier is modulated is
using Gaussian minimum shift keying (GMSK). GMSK
modulation in GSM is used because it is resilient to
noise,radiation outside the accepted bandwidth is lower
than other forms of the Phase Shift Keying and it has a
control constant power level, which allows higher
efficiency RF power amplifiers to be used in the handsets
which helps in conserving battery life. GSM bursts are
used for carrying data as well as control information.GSM
cellular system to work on a variety of frequencies, the
GSM standard defines GSM frequency bands and
frequencies for the different spectrum allocation that are in
use around the globe. GSM uses a variety of channels in
which the data is carried.These channels are separated into
physical channels and logical channels. The physical
channels are determined by the time slots where as the
logical channels are determined by the information carried
within the physical channel [1].
Omnidirectional linearly polarized antennas have been
widely used in base station mobile communications
because they can reduce the number of cell sectors and the
effects of small sectors variation [2]. The omnidirectional
antenna radiates or receives equally in all directions. It is
also called the non-directional antenna because it does not
favor any particular direction. The radiated signal has the
same strength in all directions. The gain is a parameter
which measures the degree of directivity of the antenna’s
radiation pattern. A high gain antenna will preferentially
radiate in a particular direction. Antenna gain is defined as
the ratio of intensity radiated by the antenna in the
direction of maximum output. High gain antennas have the
advantage of longer range and better signal quality. Low
gain antennas have shorter range, but the orientation of the
antenna is relatively inconsequential. If the gain of the
antenna goes up, the coverage area or angle goes down.
High gain antennas have narrow beam width and less
chance of receiving interface. Lower gain antennas have
wider beam width and a greater chance of receiving
interface [3].
The simple alternative to the adaptive beam forming
antennas is switched beam antennas. The switched beam
antennas from multiple fixed beams with heightened
sensitivity in particular directions. When the incoming
signal detected it determines the beam which is better
aligned based on SOI (signal of interest) and switches to
that beam to communicate with the user. As the mobile
unit moves throughout the cell, the switched beam system
detects the signal strength and continually switches the
beams as necessary. It subdivides sector into many narrow
beams, then each beam is considered as an individual
sector serving user or group of users.

2. Int. Journal of Electrical & Electronics Engg. Vol. 2, Spl. Issue 1 (2015) e-ISSN: 1694-2310 | p-ISSN: 1694-2426
23 NITTTR, Chandigarh EDIT-2015
Fig. 1 Block diagram of switched beam system [4].
PSN (Phase Shifting Keying), which forms multiple beams
looking in certain directions. RF switch actuates the right
beam in the desired direction. The selection of right beam
is made by control logic, which is governed by an
algorithm. The algorithm which scans all the beams and
selects the one strongest receiving signal based on
measurement made by the detector. The overall goal of the
switched beam system is to increase the gain according to
the location of the user [5, 6].
II. PROPOSED NETWORK
The proposed GSM network is designed and simulated in
Qualnet Software version 5.0.2. The Fig. 2shows the
designed and simulated network in software.
Fig.2Proposed GSM network.
This network contains various components like MS, BS,
MSC and Wireless Subnet Network. Network scenario is
developed using coverage area 1500m X 1500m. It is
formed by using 7 nodes, node 4 to 7 are MS, 1 & 2 are
BS, 3 is MSC, BSs are connected to the MSC through
wired links and a default root file is specified to make the
appropriate interface between them. The whole setup used
8 channels for traffic and control process. The Fig.3 shows
the channel properties.
Fig. 3 Channel properties
III. SIMULATION RESULTS
/
Fig. 4 shows the two calls completed. First between the
node 1 and 3 and second call is between the node 4 and 5.
Call duration between node 1 and 3 is 10 Sec. Call
duration between node 4 and 5 is 20 Sec.
A. Simulation result of change in antenna gain:
Nodes 1, 2, 3, 4, 5, 6 are MSs. Node 7 and 8 are BTSs.
Fig. 5 Signals received when the gain is changed.
Fig. 5 shows the signal received at 8 nodes. As the antenna
gain increases signal received power increases.
B. Simulation result by changing antennas:

3. Int. Journal of Electrical & Electronics Engg. Vol. 2, Spl. Issue 1 (2015) e-ISSN: 1694-2310 | p-ISSN: 1694-2426
NITTTR, Chandigarh EDIT -2015 24
Fig. 6 Signals received power by changing antennas
In above Fig. 6signals received power is changed by
changing antennas. The signal received power of
omnidirectional antenna is more than the signal received
power of a switched beam antenna.
IV. CONCLUSION
In this paper author conclude that by the increase in
antenna gain signal received power increases. By changing
the antenna the signal received power also changes. The
signal received power of omnidirectional antenna is more
than the switched beam antenna.
REFERENCES
[1] Avinash Shivajirao Pawar and Atish Shivajirao Pawar,”Study of the
GSM network” International Journal of Advanced Engineering
Research and Studies, Vol. I, Issue III, pp. 287-292,April-June, 2012.
[2] XuLinQuan, RongLin Li and Manos M. Tentzeris,”A broadband
Omnidirectional circularly polarized antenna” IEEE transaction on
antennas and propagation, vol. 61, no. 5, pp. 2363-2370, may 2013.
[3] Joseph J. Carr, ratio tech-notes, directional or omnidirectional antenna.
[4] http://image.slidesharecdn.com/smartantenns-131023072120-
phpapp02/95/smart-antenna-5-638.jpg?cb=1394008133.
[5] Zhongding Lei, Francois P. S. Chin and Ying-Chang Liang,”
Orthogonal switched beam for downlink diversity transmission” IEEE
transaction on antennas and propagation, vol. 53, no. 7, pp. 2169-2177,
July 2005.
[6] S. Bellofiore, C. A. Balanis, J. Foutz, and A. S. Spanjas, “Smart-
antenna systems for mobile communication networks, part 1: Overview
and antenna design,” IEEE Antennas Propag. Mag., vol. 44, no. 3, pp.
145–154, Jun. 2002.
ACKNOWLEDGEMENT
We heartily thankful to our supervisor, Mrs. Garima Saini,
assistant professor, department of electronics and
communication engineering, NITTTR Chandigarh for her
guidance, support and encouragement throughout the
research work. We are obliged to Dr. SBL. Sachan
professor and head, department of electronics and
communication engineering and all technical and
supporting staff of NITTTR, Chandigarh for providing the
facilities, help and encouragement for carrying out this
work.