Constructing a New Communication System by Integrating the GSM to
the Satellites Infrastructure

MUZHIR SH. AL-ANI
Department of Computer Science
Amman Arab University
Amman 11953
JORDAN
muzhir@gmail.com

BASIL M. AL-KASASBEH
Department of Computer Networks Systems
Applied Science University
Amman 11931
JORDAN
kasbasil@yahoo.com

RAFA E. AL-QUTAISH and MOHAMMAD I. MUHAIRAT
Department of Software Engineering
Alzaytoonah University of Jordan
Amman 11733
JORDAN
rafa@ieee.org, mohmuhaba14@yahoo.com


Abstract: - The current researches and industries are looking forward to integrate different technologies to get a
global technology that offers all of the intended services in a simple way. In this paper, a new communications
system is proposed to integrate the use of GSM over the available satellites infrastructures. The proposed
communications system could be used to facilitates and get benefits of both systems (the GSM and Satellites)
to achieve competitive services over the world. The proposed system is concentrated on a global
communications system that served all over the world and gives some specialization and privacy for each
country. Furthermore, this paper shows an algorithm on how to implement the GSM over satellite systems in an
efficient, flexible, and cost-effective manner.


Key-Words: - GSM, GSM over Satellite, Mobile Communications, Satellite Communications.

1 Introduction
The first artificial satellite was placed in orbit by the
Russians in 1957. That satellite, called Sputnik,
signaled the beginning of an era. The United States,
who was behind the Russians, made an all-out effort
to catch up, and launched Score in 1958, that was
the first satellite with the primary purpose of
communications. The first satellite, Sputnik 1, was
put into orbit around Earth and was therefore in
geocentric orbit. By far this is the most common
type of orbit with approximately 2456 artificial
satellites orbiting the Earth. Geocentric orbits may
be further classified by their altitude, inclination and
eccentricity [1].
The commonly used altitude classifications are
Low Earth Orbit (LEO), Medium Earth Orbit
(MEO) and High Earth Orbit (HEO). Low Earth
orbit is any orbit below 2000 km, and Medium Earth
Orbit is any orbit higher than that but still below the
altitude for geosynchronous orbit at 35786 km. High
Earth Orbit is any orbit higher than the altitude for
geosynchronous orbit [2].
Internet, cellular mobile, satellite, phones and
other communications systems construct the main
foundations of globalization that make the wide
world as a small village.
Satellites can be divided into five principal types:
research, communications, weather, navigational,
WSEAS TRANSACTIONS on COMMUNICATIONS
Muzhir Sh. Al-Ani, Basil M. Al-Kasasbeh,
Rafa E. Al-Qutaish, Mohammad I. Muhairat
ISSN: 1109-2742 217 Issue 2, Volume 8, February 2009

and applications. The growth of number of mobile
users shown in Fig. 1 and indicates that it reached to
50% of the population during 2007. Consequently
Fig. 2 shows the forecasting of population growth,
and indicates that at 2020 the world population
reaches about 7.6 billions, this means a huge
number of mobile users. Recent years show a huge
increment of world population, these needs more
communications services, and so huge investments
spend in this field to overcome these needs. This is
an indication to find new media and systems to
cover this growth [3] & [4].
However, the current researches and industries
are looking forward to integrate different
technologies to get a global technology that offers
all of the intended services in a simple way. In this
paper, a new communications system is proposed to
integrate the use of GSM over the available
satellites infrastructures. The proposed
communications system could be used to facilitates
and get benefits of both systems (the GSM and
Satellites) to achieve competitive services over the
world.
The proposed system is concentrated on a global
communications system that served all over the
world and gives some specialization and privacy for
each country. Furthermore, this paper shows how to
implement the GSM over satellite systems in an
efficient, flexible, and cost-effective manner. In
addition, since the laser inter-satellite
communication is on the verge of becoming a reality
[5] [6], it could be used with our proposed system.
The rest of this paper is organized as follows:
Section 2 gives an overview of the geosynchronous
communications satellites, section 3 presents the
details of the proposed system, and section 4
illustrates the data transmission and frame format of
the proposed system. In section 5, the
communication algorithm for the proposed system
has been explained, and finally, section 6 discusses
and concludes the paper results.
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
0
5
10
15
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35
40
45
50
years
no
. o
f m
ob
ile
u
se
rs
a
s
%
o
f p
op
ul
at
io
n

Fig. 1: Growth of mobile users
WSEAS TRANSACTIONS on COMMUNICATIONS
Muzhir Sh. Al-Ani, Basil M. Al-Kasasbeh,
Rafa E. Al-Qutaish, Mohammad I. Muhairat
ISSN: 1109-2742 218 Issue 2, Volume 8, February 2009

1940 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040
0
1
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4
5
6
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8
9
years
no
. o
f p
op
ul
at
io
n
in
b
ill
io
ns

Fig. 2: Population growth

2 Geosynchronous Communications
Satellites
In 1963, the necessary rocket booster power was
available for the first time and the first
geosynchronous satellite, Syncom 2, was launched
by NASA. For those who could see it, the satellite
was available 100% of the time, 24 hours a day. The
satellite could view approximately 42% of the earth.
However, a system of three such satellites, with the
ability to relay messages from one to the other could
interconnect virtually all of the earth except the
Polar Regions as shown in Fig. 3. A circular
geosynchronous orbit in the plane of the Earth's
equator has a radius of approximately 42,164 km
(from the center of the Earth). The one disadvantage
of the geosynchronous orbit is that the time to
transmit a signal from earth to the satellite and back
is approximately ¼ of a second - the time required
to travel 22,236 miles (35,786 km) up and 22,236
miles back down at the speed of light. For telephone
conversations, this delay can sometimes be
annoying. For data transmission and most other
uses, it is not significant. In any event, once Syncom
had demonstrated the technology necessary to
launch a geosynchronous satellite, a virtual
explosion of such satellites followed [7] [8].
During the last years, the number of commercial
communications satellites in geosynchronous has
been increased [9].
Today, there are approximately 150
communications satellites in orbit, with over 100 in
geosynchronous orbit. One of the biggest sponsors
of satellite development was Intelsat, an
internationally-owned corporation which has
launched 8 different series of satellites (4 or 5 of
each series) over a period of more than 30 years.
Spreading their satellites around the globe and
making provision to relay from one satellite to
another, they made it possible to transmit 1000s of
phone calls between almost any two points on the
earth. It was also possible for the first time, due to
the large capacity of the satellites, to transmit live
television pictures between virtually any two points
on earth [10] [11].
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Low earth orbit satellite systems are designed to
provide global communication for multimedia
services, including voice, video and data. In design
of LEO systems, the choice of satellite altitude is an
important consideration, which has a significant
impact on system performance [12]. The delay of
the propagation signal is very important voice signal
and it must be with the range of 200 mille-seconds,
and this range is available and achievable with LEO
satellite [13].


3 The Proposed System
The worldwide popularity of cellular mobile has
driven operators to deploy services in most
metropolitan areas and, increasingly, into smaller
areas. Often the terrestrial infrastructure is not
sufficient to reach these locations and satellite is the
only viable way to extend the service into these
regions. Furthermore, the daily exposure to GSM
electromagnetic fields has raised public concern of
possible adverse health effects to people living in
the near of base station antennas [14]. However, the
proposed communication system will overcome this
problem since there are no electromagnetic fields.
The implementation of cellular mobile over
satellite is in common use in many regions of the
world. While cellular mobile is inherently satellite
friendly and it is easy to implement in a simple way,
so there are more approaches which can lead to
significant bandwidth, and therefore cost,
reductions.




Satellite3 Satellite2 Satellite1
Coverage
Area
Earth
Fig. 3: The envelope of three satellites

The proposed system divides the world into areas
that each area contains on a number of countries and
can be covered by one geosynchronous satellite, so
it is possible to assume that 24 satellites can be
cover all the areas of the world (as in Geographic
Information System). The proposed system as
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Muzhir Sh. Al-Ani, Basil M. Al-Kasasbeh,
Rafa E. Al-Qutaish, Mohammad I. Muhairat
ISSN: 1109-2742 220 Issue 2, Volume 8, February 2009

shown in Fig. 4 can be divided into two parts; the
first one is the Global Extra Communication System
(GECS), that concern with the satellite
communication between users outside of areas and
countries. GECS depends on geostationary satellite
through Earth Stations (ESs), where the
communications of each area goes through a
GateWay (GW) unit that makes security and privacy
for each country as well as identifies the authority
and legality for each user. The second one is the
Local Intra Communication System (LICS), that
concern with the mobile communication between
users inside of areas and countries. LICS depends
on mobile communication systems networks
through Base Stations (BSs), where the
communications through of each area goes through
a central center that dominant all the internal
communications and operates as a pre-filter link to
the gateway to achieve the external
communications.


BS1BS2BS3BSn
ES1ES2ES3ESn
SA1
SA2
SA3SAn
A
re
a
(1
)

A
re
a
(2
)

A
re
a
(3
)

A
re
a
(n
)

GW1GW2GW3GWn



Fig. 4: The architecture of the proposed system


The local operation (internal access) starts when
a signal is transmitted to a local subscriber, so this
operation passes through a mobile network, then to
the nearest base station, then to the indicated
subscriber. The global operation (external access)
starts when a signal is transmitted to a global
subscriber, so this operation passes through a
satellite network to the area gateway of the source
subscriber, then via inter-satellite links passes to the
area gateway of the destination subscriber, then to
the indicated subscriber.

4 Data Transmission and Frame
Format
Geosynchronous system has large bandwidth that
supports multimedia services including voice, data,
and video services, in addition of other services. The
main problem of geosynchronous is the delay time
that occurs due to large signal propagation. To
overcome this problem, the length of the transmitted
frame is chosen as minimum as possible (one byte).
The global system is divided into 24 areas and each
area divided into a number of countries depending
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Muzhir Sh. Al-Ani, Basil M. Al-Kasasbeh,
Rafa E. Al-Qutaish, Mohammad I. Muhairat
ISSN: 1109-2742 221 Issue 2, Volume 8, February 2009

on the coverage of the satellite, in total of 192
countries. Therefore it must be 192 fixed addresses
for all countries, and that are indicated by
geosynchronous satellites. The international
transmitted data are encapsulated by internal mobile
network and then encapsulated by external satellite
network and directed to the destination country (one
of 192).
Base Transceiver Station (BTS) is the equipment
which facilitates the wireless communication
between user equipments (UE) and the network.
Typically a BTS will have several transceivers
which allow it to serve several different frequencies
and different sectors of the cell. A BTS is controlled
by a Base Station Controller (BSC) via the Base
station Control Function (BCF). A number of BSCs
are served by an MSC. The Mobile Switching
Center (MSC) is the primary service delivery node
for GSM, responsible for handling voice calls and
SMS as well as other services. The outdoor
communications are transmitted via a global mobile
service switching center (GMSC), which is a
gateway used to interconnect two satellites.
The proposed system depends on the LEOs
satellites to overcome the adequate delay that is with
the limit of 200 msec. The distribution of satellites
depends on the compensation between two main
factors that are the area and the population density
of each country, so we suggest 256 satellites are
available to overcome the coverage of all countries
as shown in Fig. 5. The global mobile frame is
encapsulated via the satellite frame before
transmitted consist of identification of satellite (Sat.
ID), destination (Des. ID), and source (Sou. ID) as
well as starting byte and end byte, four byte of
trailer and 1500 byte of payload as illustrated in Fig.
6.




Fig. 5: The architecture of Mobile over Satellite system destination

BTS BTS
BSC1 BSCn
MSC GMSC
MSC GMSC BSC1
BTS
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Mobile over Satellite Frame
Fig. 6: The composite frame structure of the proposed system

5 Communication Algorithm for the
Proposed System
The proposed system can perform the operation
through the following algorithm. As a first step of
this algorithm, the authentication process should be
carried out. The authentication process is based on a
challenge-response method in which the
authentication key is available in the authentication
centre and the SIM card of the given mobile device.
The authentication canter selects a random
number of length 128 bits and calculates a signal
response value (SR*) using the well-known A3
authentication algorithm. Whereas, on the mobile
device side, the mobile calculates the SR value
using the following: the same selected random
number (of size 128 bits), the authentication key
which is already available in the SIM card, and the
well-known A3 authentication algorithm. Finally, to
give an access to the service, the HLR (or VLR if
the mobile is located in a foreign zone) have to
check that the SR* and the SR are identical,
otherwise, the access is denied [15]. Figure 7
illustrates the authentication process.
Figure 8 illustrates where the main elements of
the authentication process located inside the GSM
network.










Fig. 7: The Authentication Process
1B 1B 1B 1B 1B 1500B 1B 4B
Sat.
Payload Header
GSM
Frame
Sat. Des. Sou.SF Type Payload End Trailer
ID ID ID
128 bits
Random Number
A3 A3
Authentication Key
Authentication Centre Mobile Device
Authentication Key
SR SR*
Using HLR or VLR

SR*=SR?
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Fig. 8: The Structure of a GSM Network (key elements) [16]

The rest of the algorithm - see Figure 9 for the
full algorithm - is constructed by three branches as
the following:
First branch is related to the traditional
communication approach between mobiles
within the same provider. This approach starts
with the mobile request and after authentication
it goes through channel allocation in the BSC
then to MSCx and when the communication is
on the same provider, the way take place to the
indicated destination through BSC and BTS.

Second branch is related to the traditional
communication approach between mobiles with
different providers. This approach starts as the
previous one but goes through GMSC1 when
the external call (local but not the same
provider) is selected and there is no need for
satellite link. Then goes to the destination
mobile through PSTN, GMSC2, MSCy, BSC,
and BTS.

Third branch is related to new communication
approach between mobiles with different PSTN.
This approach starts as the second one but it is
selected when the communication occurs
through satellite link. Then, the information
passes through to the sending satellite base
station, satellite channel allocation, frame
encapsulation, and indicated satellite(s). The
information received by the receiving satellite
base station to destination mobile through
GMSC3, MSCz, BSC, and BTS.

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Start
Fig. 9: Proposed communication system algorithm
No
Yes
No
Access Denied Authentication
Channel Allocation
MSCx
Another Provider BSC BTS Destination
GMSC1
Local Provider
MSCy BSC BTS Destination
PSTN GMSC2
Sending Sat.
Base Station
Sat. Channel
Allocation

Satellite(s)
Receiving Sat.
Base Station
Frame
Encapsulation
GMSC3
MSCz
BSC
BTS
Destination
First Branch
Second Branch
Third Branch
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6 Conclusion
The current researches and industries are looking
forward to integrate different technologies to get a
global technology that offers all of the intended
services in a simple way. In this paper, a new
communications system has been proposed to
integrate the usage of GSM over the available
satellites infrastructures. The proposed
communications system could be used to facilitates
and get benefits of both systems (the GSM and
Satellites) to achieve competitive services over the
world. The proposed system has been concentrated
on a global communications system that served all
over the world and gives some specialization and
privacy for each country. Furthermore, this paper
showed how to implement the GSM over satellite
systems in an efficient, flexible, and cost-effective
manner.
The proposed integrated communication system
will overcome a set of problems, such as, coverage
area, handovers, mobility, bandwidths, and health
concern. The proposed system can serve all
countries over the world without any limitation
taking into account the privacy of each country.
However, the only problem that can be raised from
the proposed system is the compensation and
synchronization between the numbers of satellites
that float via the space.
However, the implementation of mobile
communications over satellite systems leads to a
global efficient and flexible system that offers huge
number of adequate services over the world. The
proposed system contains numbers and address of
calls and information which allows each user to
select those corresponding transmissions. The
synchronization between satellites including
coverage area, handover and frame format must be
well-designed to overcome all of the raised
problems.
As a future work, the proposed system could be
implanted using the GPRS, EDGE, and 3G mobile
systems instead of 2G (GSM2) mobile systems.


References:
[1] D. A. Vallado, Fundamentals of Astrodynamics
and Applications, Microcosm Press, 2007.
[2] M. Ken, Types of Satellites, EzineArticles,
Online: http://ezinearticles.com/?Types-of-
Satellites&id=408061, accessed on May 08,
2008.
[3] United Nations, the world at six billon, Online:
http://www.un.org/esa/population
/publications/sixbillion/sixbilpart1.pdf,
accessed on May 08, 2008.
[4] Texas Instruments Incorporated, The next
billion mobile phone user, Online:
http://focus.ti.com/pdfs/wtbu/ti_emergingmarke
ts.pdf, accessed on May 5, 2008.
[5] M. S. Mazalkova, The system transfering
between laser-satellites, WSEAS Transactions
on Communications, Vol. 7, No. 7, 2008, pp.
152-159.
[6] M. Reyes-Ayala, E. A. Andrade-Gonzalez, J.
A. Tirado-Méndez, H. J. Aguil, Analysis of
Non-Linear Response in DS-CDMA Satellite
Systems, WSEAS Transactions on
Communications, Vol. 7, No. 4, 2008, pp. 235-
241.
[7] L. Nagy, Satellite Communications, Online:
http://ctd.grc.nasa.gov/rleonard/, accessed on
May 8, 2008.
[8] D. Hart, Satellite Communications, Online:
http://www.cse.wustl.edu/~jain/cis788-7/ftp/
satellite_nets.pdf, accessed on May 8, 2008.
[9] R. D. Briskman, IEEE Transactions on
Broadcasting, Vol. BC-33, No. 1, 1987, pp. 27-
30.
[10] International Telecommunications Union, ITU
Handbook on Satellite Communications, 3rd
ed., Wiley InterScience, 2002.
[11] D. Roddy, Satellite Communications, 4th ed.,
McGraw-Hill Professional, 2006.
[12] B. Gavish and J. Kalvenes, The impact of
satellite altitude on the performance of LEOS
based communication systems, Wireless
Networks, Vol. 4, No. 2, 1998.
[13] N. Blefari-Melazzi, M. Femminella and F.
Pugini, A Layer 3 Movement Detection
Algorithm Driving Handovers in Mobile IP,
Wireless Networks, Vol. 11, No. 3, 2005.
[14] M. Ibrani-pllana, L. Ahma, E. Hamiti and R.
Sefa, Human exposure assessment in the
vicinity of 900 MHz GSM base station antenna,
WSEAS Transac tions on Communications,
Vol. 7, No. 4, 2008, pp. 229-234.
[15] J. Schiller, Mobile Communications, 2nd Ed.,
Addison Wesley, 2003.
[16] Wikipedia, GSM, online: http://en.
wikipedia.org/wiki/GSM, accessed on: May 9,
2008.

WSEAS TRANSACTIONS on COMMUNICATIONS
Muzhir Sh. Al-Ani, Basil M. Al-Kasasbeh,
Rafa E. Al-Qutaish, Mohammad I. Muhairat
ISSN: 1109-2742 226 Issue 2, Volume 8, February 2009