Intro to telecommunication (MISY3321)
Spring Semester, 2012 May 15
201
Dr. Valentina Korzhova
ZAIN a Wonderful World
Marwa Al-Enizi
Malika Faisal Al-Sharif
Mada Al-Enizi
Kawthar Al-Amoudi
Outline
1. Introduction
1.1. History of network…………………………………………………..
1.2. Purpose………………………………………………………………
2. Network transmission media………………………………………………
3. Network classification
2.1. Connection methods…………………………………………………
2.2. Network architecture…………………………………………………
2.3. Network topology……………………………………………………
4. Types of networks based on physical scope……………………………….
5. Basic hardware components……………………………………………….
6. Network security……………………………………………………………
7. Summary
6.1. Conclusion…………………………………………………………..
6.2. Recommendation…………………………………………………….
1. Introduction
1.1. History of network:
The Internet was the result of some visionary thinking by people in the early 1960s who saw
great potential value in allowing computers to share information on research and development in
scientific and military fields. J.C.R. Licklider of MIT, first proposed a global network of
computers in 1962, and moved over to the Defense Advanced Research Projects Agency
(DARPA) in late 1962 to head the work to develop it.
Since the mid-1990s the Internet has had a drastic impact on culture and commerce, including
the rise of near-instant communication by electronic mail, instant messaging, Voice over Internet
Protocol (VoIP) "phone calls", two-way interactive video calls, and the World Wide Web with
its discussion forums, blogs, social networking, and online shopping sites.
Nowadays the connections expanded to more educational institutions, and even to a growing
number of companies such as Zain Company. Zain is the company that we did the research about
it for our project.
Here is a brief history about Zain. It is a mobile telecommunications company founded in
1983 in Kuwait as Mobile Telecommunications Company, and was later rebranded to Zain in
2007. Zain has commercial presence in 7 countries across Africa and the Middle East such as
Saudi Arabia, Lebnon, Bahrain, Iraq, Sudan and Jordan with about 37.6 million customers as of
31 March 2011. It employs more than 6000 people around the world.
Zain launched its commercial operations in the Kingdom of Saudi Arabia on 26 August 2008,
a year after it was awarded its mobile license. The Group holds management control of the
operation through its 25% ownership stake.
1.2. Purpose:
The purpose of this Zain Network Company in general they want to be the leading global
mobile operator that provides professional, world-class mobile and data services to all the
customers, wherever they are. Zain company aim to achieve this by exceeding their customers
expectations,
rewarding
their
employees.
As
a
business,
Zain
understands
that
telecommunications have forever changed the way people communicate and interface with their
environments. Zain Telecom Company is new in the telecommunication networking in Saudi,
and it has many services to provide to the customers. Therefore, Zain Company interred the
market with strong networking offering so they can compete with other networking company in
Saudi Arabia and prove that there the best in the telecom field. Moreover, computer networking
is very importance in a business as it increases the interaction capability of the entire business.
Therefore, this report will examine Zain co. from an information system perspective. The
research will covered several aspects such as what is the network classification they use, types of
networks based on physical scope, basic hardware components, and network security used to
protect the firm.
Zain is the newest player in the mobile telecommunication market of Saudi Arabia. We
strive to become the preferred choice for voice, messaging, multimedia, call management, data
and other services in the Kingdom. Building on the expertise of the Zain Group and the insights
of our local team, we are building a trusted and effective telecommunication provider for the
largest country in the Middle East.
Zain Values

Radiance: leading the way with imagination and vision
Heart: living our lives with courage, resolve and emotions
Belonging: being part of the community spirit that knows no territorial boundaries
Zain Services
Voice services (calls, international roaming, voicemail, conference call, voice SMS)
SMS and MMS services
SIM applications (subscription channels, downloadable pictures, ringtones, games,
applications...)
3G and 3.5G services (video call, daily downloadable comedy...)
Zain figures
93% of Saudi Arabia, 43 cities and 67 highways covered at launch
More than USD 1.3 billion investment committed to the network build-up
More than 2,200 staff
2. Network transmission media:
In any computer networking, there are several connection methods that help the individual
devices to communicate and interact together. Therefore, Zain Co. as a mobile network
communication they have some of methods they use in their company so they can provide a good
service to their customers and be the leading telecommunication company in the kingdom and
compete with other mobile networking. They use in their transmission media
•
Optical Fiber
•
Wired
•
Wireless
•
Point-to-Point laser
According to Zain Co., they use three out of the four listed methods; which are: wired,
wireless, and point-to-point laser. First, wired technologies that consist of three types: twisted
pair, coaxial cable, and optical fiber (Rodriguez, E. 2005). Some of the main advantages of using
wired technologies are equipment is cheap as well as the maintenance, the copper-the wire usedhas a long life expectancy, and wired technologies have high speed in delivering information.
Out of these three kinds, Zain Co. uses twisted pair, coaxial fiber and Optical Fiber. Twisted Pair
is the most used medium globally, it consist of two copper wires that are twisted to become one
wire. Although twisted pair is immune to most background radiation, the wiring does not solve
all problems because it have problem with strong electrical noise, and high frequencies used for
communication. Also, Zain Co. use the coaxial fiber as It widely used for computer networks,
Although more expensive than standard telephone wire, it is much less susceptible to
interference and can carry much more data that’s why they use it in the company so they can
save much customers data. Further, the Optical Fiber is formed of filaments of glass covered
with protective layers. Optical wires carry information more than copper wires (Finisar, C.
1998).
Second type of network transmission media is wireless technologies which can send
information like the wired technologies, except that it does not use wires. Instead use Terrestrial,
Satellites, and Wireless local area networking (LAN). Wireless connections have many
advantages, and it is becoming a priority in every new invention especially in Zain Co. because
they have an internet wireless option to their customer and they use 2G, 3G, and 4G. Wireless
technologies are more convenient and cannot break unlike wires (Rodriguez, E. 2005).Zain Co.
is using two of the three types that is satellites and local area network Wireless (LAN).A satellite
internet connection is an arrangement in which the upstream outgoing and the downstream
incoming data are sent from, and arrive at, a computer through a satellite and it is good for Web
browsing and for downloading files because it have a long latency compared with purely landbased systems. Moreover, they use wireless Local Area Networks (LAN) which is similar to
digital cellular but with higher radio frequency and it allows devices to communicate in a limited
small area like the offices and home.
Third, point-to-point laser enables transferring information between two devices that are clear
and there are no hindrances between them over a wide area network and it consists of many
connections between individual pairs of machines and they use it in Zain Co.
Moreover, there are network classifications in networking and it divide to two Networks
architecture and network topology and we can say the difference between them the same
between logical and physical architecture is about the logical design of the network and the
topology is the physical elements required to enable the architectural design. The network
architecture contains active network, Clint-server and peer to peer. And the network topology
contain bus network, star network, ring network and mesh network. Zain Co. uses in their
telecommunication system the three type of architecture system and they use only mesh and star
network from the topology system. Mesh network is a type of wireless networking that uses
redundant and distributed nodes to provide greater reliability and range for any given wireless
network. Also, Mesh network software is built around the idea of self-healing networks, capable
of routing signals efficiently through complex series of nodes and continuing to work effectively
even when some nodes are down and The idea of providing wireless Internet in Zain Co and
have many options for customer to choose the best one. Furthermore, Star network are one of the
most common computer network topologies and it have a very simplest form and star network
reduces the chance of network failure by connecting all of the systems that’s why Zain Co. use it
in their system.
2.1. Client server definition:
Client/server describes the relationship between two computer programs in which one
program, the client, makes a service request from another program, the server, which fulfills the
request. Although programs within a single computer can use the client/server idea, it is a more
important idea in a network. In a network, the client/server model provides a convenient way to
interconnect programs that are distributed efficiently across different locations. Computer
transactions using the client/server model are very common. For example, to check your bank
account from your computer, a client program in your computer forwards your request to a
server program at the bank. The client/server model has become one of the central ideas of
network computing. Most business applications being written today use the client/server model.
In marketing, the term has been used to distinguish distributed computing by smaller dispersed
computers from the "monolithic" centralized computing of mainframe computers. In the usual
client/server model, one server, sometimes called a daemon, is activated and awaits client
requests. Typically, multiple client programs share the services of a common server program.
Both client programs and server programs are often part of a larger program or application.
2.2. Star network:
Star networks :are one of the most common computer network topologies. In its simplest
form, a star network consists of one central switch, hub or computer, which acts as a conduit to
transmit messages. This consists of a central node, to which all other nodes are connected; this
central node provides a common connection point for all nodes through a hub. Thus, the hub and
leaf nodes, and the transmission lines between them, form a graph with the topology of a star. If
the central node is passive, the originating node must be able to tolerate the reception of an echo
of its own transmission, delayed by the two-way transmission time (i.e. to and from the central
node) plus any delay generated in the central node. An active star network has an active central
node that usually has the means to prevent echo-related problems.
The star topology reduces the chance of network failure by connecting all of the systems to a
central node. When applied to a bus-based network, this central hub rebroadcasts all
transmissions received from any peripheral node to all peripheral nodes on the network,
sometimes including the originating node. All peripheral nodes may thus communicate with all
others by transmitting to, and receiving from, the central node only. The failure of a transmission
line linking any peripheral node to the central node will result in the isolation of that peripheral
node from all others, but the rest of the systems will be unaffected.
It is also designed with each node (file servers, workstations, and peripherals) connected directly
to a central network hub, switch, or concentrator.
Data on a star network passes through the hub, switch, or concentrator before continuing to
its destination. The hub, switch, or concentrator manages and controls all functions of the
network. It is also acts as a repeater for the data flow. This configuration is common with twisted
pair cable. However, it can also be used with coaxial cable or optical fibre cable.
Advantages:

Better performance.

Isolation of devices.

Benefits from centralization.

Easy to detect faults and to remove parts.

No disruptions to the network when connecting or removing devices.
Disadvantages:

High dependence of the system on the functioning of the central hub

Failure of the central hub renders the network inoperable .
2.3. Mesh network:
A mesh network is a type of wireless networking that uses redundant and distributed nodes
to provide greater reliability and range for any given wireless network. A number of smaller
nodes, called repeaters, connect to large nodes or wireless routers to provide coverage over a
larger area than would be possible with a wireless router alone. Mesh network software is built
around the idea of self-healing networks, capable of routing signals efficiently through complex
series of nodes and continuing to work effectively even when some nodes are down.
The idea of providing wireless Internet to large numbers of people became very appealing
after the advent of cheap wireless cards in the mid-90s, which thereafter allowed the Internet to
become a mobile, often inexpensive phenomenon.
3. Types of networks based on physical scope:
Zain in Saudi Arabia is looking for outstanding professionals who share their vision about
building their company to become the international model for a successful telecom operator
beating all records of any third entrant.
Network Solutions: Zain can connect all the computers of business currently owns so that
employees can share the same programs, files, printers, backup capabilities, or Internet
connections. We can set up wireless connections.
TheZain offers networking hardware and software from all major system vendors, as well as
fully trained and certified network computing professionals to support your network. TheZain
can fulfill all your needs, from a peer to peer network, Local Area Network, or to a Campus or
Wide Area Network. Zain offers several different solutions for getting your office online. Zain
offers many types of communications and connectivity solutions including:
• Network Design
• Network Consulting
• Professional Wiring
• Network Installation
• Network Support Contracts
• Network Shared Internet Access
• Network Fax Servers
• Voice over IP Telephony Products
3.1. Wide Area Network:
A wide area network (WAN) is a geographically dispersed telecommunications network.
The term distinguishes a broader telecommunication structure from a local area network
(LAN). A wide area network may be privately owned or rented, but the term usually
connotes the inclusion of public (shared user) networks. An intermediate form of network in
terms of geography is a metropolitan area network (MAN). Zain provide service which called
roaming that guarantees a perfect roaming experience. At the end of the horizon, you can still
roam with Zain, wherever your destination is, you will find at least one Zain roaming partner.
Enjoy the following services while abroad:

Make and receive calls.

Send and receive SMSs

Send pictures and video shots with the MMS service.

Access high speed Internet and e-mail through your mobile.
3.2. Enterprise Area Network:
An enterprise WAN is a corporate network that connects geographically dispersed users
areas that could be anywhere in the world. As is the case with mostWANs, an enterprise WAN
(wide area network) links LANs in multiple locations. The enterprise in question often owns and
manages the networking equipment within the LANs. However, the LANs are generally
connected by a service provider. An enterprise WAN often also has additional remote users
connecting through a virtual private network (VPN). Zain provide a service called One Network
has four innovative features while roaming!
While roaming on the word’s first borderless network, you can now:
 Receive
all calls with the most attractive rates
 Make Calls
at local rates according to the country you are in
 Recharge with
 Call
local recharge cards
your country’s Customer Care center for free
Countries where One Network is available: Jordan, Bahrain, Iraq, Sudan, Ghana, Niger, Uganda,
Burkina Faso, Republic of Congo, Democratic Republic of Congo, Gabon, Chad, Tanzania,
Kenya, Malawi, and Nigeria.
3.3. Home Area Network:
A HAN is a network contained within a user's home that connects a person's digital devices,
from multiple computers and their peripheral devices to telephones, VCRs, televisions, video
games, home security systems, "smart" appliances, fax machines and other digital devices that
are wired into the network. Zain provide this services for people Zain broadband No matter what
your needs for wireless Internet are, you will find a Zain Broadband plan that will match them,
choose from the different Zain Broadband data plans to use it on your desktop computer, laptop,
or tablet.
4. Zain Basic Hardware Components:
4.1. Network interface cards:
A NIC or network interface card of Zain company allows to gain access to the local network
or the internet. Without a network interface card, you cannot send or receive emails, watch
youtube, print to network printers, or play video games online. However, that's not to say the the
computer is completely useless without it, but It allows users to connect to each other either by
using cables or wireless. For example, Zain NIC can be picked up for about 15 sr on average for
4G from your local best buy.
4.2. Repeaters:
Zain is the pioneer of mobile telecommunications in the Middle East. So they are a leading
mobile and data services operator with a commercial footprint in 7 Middle Eastern countries with
a workforce of 6,000 providing a comprehensive range of mobile voice and data services to over
37.6 million** active individual and business customers (March 31, 2011). And they contact
their costumers by emailing them or sending them messages to their mobiles.
4.3. Hubs:
Zain company has these simple, affordable but effective small boxes provide a central
connection point for the networking of multiple computers. The Zain hub contains multiple
ports. When a packet arrives at one port, it is copied to all the ports of the hub. When the packets
are copied, the destination address in the frame does not change to a broadcast address. It does
this in a rudimentary way, it simply copies the data to all of the Nodes connected to the hub.
4.4. Bridges:
A bridge device filters data traffic at a network boundary. Traditional bridges, though, support
one network boundary, whereas switches usually offer four or more hardware ports. Bridges
learn the association of ports and addresses by examining the source address of frames that it
sees on various ports. Once a frame arrives through a port, its source address is stored and the
bridge assumes that Zain address is associated with that port. they uses different format of
network in their companies.
4.5. Switches and Routers:
The default user is admin with a password of admin. The admin user can create other users.
Zain company recommended that the default admin password is modified the first time the
admin user logs on. And there are two user privilege levels: administrator users have full
configuration rights. And the other way is by let the other users can monitor, but cannot execute
any configuration operations. Zain Router is developed by Zain and is used by 3 users of
Software Informer. The most popular version of this product among our users is 1.0.
5. Network security:
5.1. Firewalls and Encryption:
Managed Firewall and Virtual Private Network Service
As companies continue to enlist the Internet to expedite business processes, the incurred
security risk grows. Today, many organizations provide network access to partners,
suppliers, customers, and mobile employees, which foster opportunities for people with ill
intent. Although these organizations may have established strong perimeter security, it is
only a first line of defense. For an organization to effectively safeguard critical information,
it takes more than integrating the latest security hardware and software.
Bottom Line:
A complete security program, which includes around-the-clock management and
monitoring, real-time security intelligence, global infrastructure, as well as a staff of 24/7
security experts, are key elements to keeping pace with today’s increasingly complex
network security threats. Security policies and configurations must be updated to ensure
appropriate access controls are consistent with changing corporate environments. In many
cases, companies struggle to allocate the appropriate resources toward core competencies and
security requirements. The Zain Managed Firewall and Virtual Private Network (VPN)
Service relieves organizations of having to staff expert 24/7 firewall management,
monitoring, and support internally.
Description
The Zain Managed Firewall and VPN Service protect an organization’s key information
assets across networks, hosts, applications, and databases. Zain MSS highly trained security
experts become an extension of each customer’s in-house IT staff, providing analysis,
configuration, setup, alerts, and 24/7 system management. The customized firewall services
harness industry best practices to ensure a high level of network access and information
availability, integrity, and privacy. Around-the-clock firewall monitoring generates
immediate alerts and responses for service outages and security alerts associated with critical
Internet access points.
- Service Features include:
o
Configure and provision devices
o
Notify customers of major security and health issues and provide event descriptions,
context, and high-level remediation
o
Upgrades and patch management
o
Change firewall rules
o
Offer flexible reporting options on client portal
o
Correlate firewall log data with information collected from other managed devices and
from the Managed Vulnerability Protection Service (MVPS)
o
Offer seamless integration with our co-brand partner I(TS)² Incident Response and
Computer Forensics team

o
Forward firewall logs for archiving and forensics
o
Integrate new product enhancements when released by vendors
o
Offer quality assurance
o
Client-to-site VPN
o
Site-to-site VPN
Upgrades:
High Availability—The SecureWorks redundant firewall architecture options, which
include automatic failover and clustering approaches; can be added to mission-critical
environments to ensure continuity of network access and information availability.
VPN Service Option—SecureWorks delivers a highly secure and reliable industrystandard VPN service, with 24/7 management and monitoring support. This service meets the
business needs of both site-to-site and remote user VPN access. The service includes
industry-standard authentication and encryption technologies to ensure the confidentiality,
availability, and integrity of communications between sender and recipient.
- Supported Platforms:
o
Cisco PIX
o
Juniper
o
Check Point
o
Nokia
o

Secure Computing
Key Benefits :
Unmatched Security Intelligence - Zain Managed Firewall and VPN Service leverages
SecureWorks intelligence to deliver intra-enterprise, inter-enterprise and Internet-wide
security intelligence. SecureWorks has unique visibility into Internet security threats, with
over 2600 clients globally.
Comprehensive Deployment Services – Zain MSS security engineers and program
managers ensure that the intrusion prevention devices are staged and comprehensively tested
prior to deployment.
Full Life-Cycle Management – Zain delivers true life-cycle management on an ongoing
basis. Security Monitoring and Risk Management - 24x7 monitoring of security events,
which are captured, analyzed and correlated in real-time. Suspicious and malicious events are
therefore proactively identified, mitigating an organization’s risk potential. When combined
with MSS’s consulting services, the company’s security experts immediately execute
remediation plans.
Health and Performance Monitoring - 24x7 proactive monitoring for health and
performance of devices. This allows Zain MSS to proactively address developing operational
problems prior to actual service failures.
Guaranteed Responsiveness – Zain MSS commences a client-specific escalation
procedure the moment a problem is detected and then works quickly to identify its source.
Reliable Communication/Management Channel - SecureWorks’ proprietary Security Defense
Appliance (SDA) provides a secure, fault-tolerant communication and management channel.
The SDA, located behind a customer’s security devices, provides secure, event store-and-
forward capabilities via an encrypted connection to the Security Operations Centers (SOCs).
Deployment of the SDA is not required, but highly recommended.
Trained and Dedicated Professionals – Zain MSS has an extensive team of certified
security professionals who are specially trained to manage security products of leading
industry vendors.
Lower Total Cost of Ownership - Zain Managed Firewall and VPN Service saves
organizations time and money by reducing staffing, training, maintenance and upfront capital
expenditures.
5.2. Security technology:
Zain Network with the introduction of 4G LTE, ZAIN is the only operator that offers 4G
services in the Kingdom that deliver internet speed that reaches up to 100 Mbps
4G - LTE
LTE (Long Term Evolution) is a wireless broadband technology designed to support internet
speed up to 10x faster than 3G
HSPA+
HSPA+ technology support internet speed up to 4x faster than the already available 3G network
HSPA
The 3G technology that powers our fast mobile broadband network

Network Spectrum:
Zain’s license includes usage of the global spectrum for 2G (GSM) services in the 900
MHZ and 1800 MHZ plus 3G (UMTS) services in the 2100 MHZ spectrum and LTE in 1800
MHZ. Zain plans to expand the allocated 2100MHz spectrum to enhance the offered MBB
services to higher speeds in line with market needs (>42Mbps). The network also uses various
frequency bands to provide backhaul and backbone transmission as needed by the network. In
addition to the microwave links, we have also leased fiber lines and dark fibers with DWDM to
provide high capacity backbone transmission links supporting the existing microwave and
providing interconnections with other operators’ networks. For future expansions, we also plan
to expand the microwave and DWDM transmission to extend service areas to new cities and
remote villages and roads.

Zain technology:
Zain primary network technology platform is based on the latest 2G, 3G, HSPA and LTE
global standards. The network was designed to provide reliable services; it incorporates several
levels of protection to keep the network running during various breakdown con- ditions. As a
result our network provided stable and reliable services during high traffic conditions in
Ramadan and during the last Hajj 1432 H season. Also, the designed capac- ity of the network
has enabled the network to accommodate the increasing numbers of subscribers and will be able
to cater for higher capacity as our market share grows. The network is highly scalable and
flexible to accommodate increasing numbers of subscrib- ers in line with the marketing roadmap
and the anticipated growth in our market share.
5.3. Authentication:
Zain ksa is the new name for the telecommunications company, which entered the Saudi
market over the last three years to the forefront with its technical approach and innovative
marketing.
Zain ksa is the first company in the Middle East in terms of access to quality certificate ISO
27001: 2005 ISO and that support networks and mobile telephony services, recently
characterized by its ability to maintain credibility and international recognition Zain , is a mobile
telecommunication company based in Kuwait, founded in 1983 as Mobile Telecommunications
Company (MTC), and was later rebranded 'Zain' in 2007. Zain operates in 24 countries, 8 of
them are in the Middle east, and 15 countries in Africa. It's employees are estimated 15,000 as of
June 30, 2009.
Zain announced a service called “One Network”, described by Zain as ‘’the world’s-first,
borderless mobile service to its users in all regions”.
The company meant it’s service as a “cost-effective and convenient solution designed to fit
customers’ regional and continent-wide communications needs by taking advantage of Zain
Group’s unique pan-Middle East and pan-African presence.
” At first, It announced that it will link four of its Middle East country operations into a single
network for users.
Conclusion:
Zain Network
To cope with the growth in the business segment in the Saudi Market, there will be the need
for an efficient communication network that should handle all business mobile needs. From
Voice to Data and from Necessities to added values, Zain has developed a mobile solution that
fits business requirements. An efficient solution with a wide coverage network (locally &
globally) that would cover all areas within your strategic business plans & beyond.
Zain solutions are reliable, simple & universal. Reliable to fit where needed & accommodate
all your business mobile communications. Simple to structure, use & adapt. And universal to
give you state of the art mobile technology which would lie nowhere below the high end global
mobile technology trend
Recommendation:
1. Zain IT:
In 2012 and beyond, Zain should plann for more expansion and enhancement of IT Infrastructure/Applications; the key initiatives are highlighted below:
•
Implementing Convergent-charging system to optimize charging, product devel opment
and customer experience by reducing the OpEx.
•
Infrastructure optimization using virtualization & consolidation, which will reduce Opex
and increase the efficiency in IT systems.
•
Continue the development and enhancement of the IT applications Architecture to
support the introduction of more and new services to our customers, with an en hanced
time to market lifecycle.
•
Further improve the “customer experience” oriented end to end KPI’s ensuring the best
services to Zain customers.
2. Zain business :
In line with Zain’sbusiness direction to continue improving network quality, the Company
shuld plan for vast expansion of their current network coverage and capacity. To accom- plish
this strategy, key projects have been identified;
•
Expand 2G/3G network for coverage and capacity; minimum 3G capacity is 21Mbps.
•
Expand on LTE network in all major cities in Saudi Arabia including three LTE core
locations with VoLTE capability.
•
Complete rollout of our fiber network project to significantly reduce current Leased Line
Opex
•
Enhance indoor coverage with building dedicated indoor solutions to provide best levels
of 2G/3G/HSPA services..
•
Eliminating national roaming by increasing Zain foot print in uncovered areas.
•
Enhancing core resiliency and capacity. Modernizing Transmission and Radio with
latest technologies
•
Outsource a large portion of the Network / IT services with one vendor to reduce
overall OPEX and improve on the quality of those services provided.
References:
Finisar, C. (1998). Optical Fiber (fiber optic, from
http://searchtelecom.techtarget.com/definition/optical-fiber
http://en.wikipedia.org/wiki/Home_network
Rodriguez, E. (2005). Wired vs. Wireless, from
http://www.skullbox.net/wiredvswireless.php
In Wikipedia, from
http://en.wikipedia.org/wiki/Star_network
Anissiomy,M.(2003).Mesh Networ, from
http://www.wisegeek.com/what-is-a-mesh-network.htm
Andrew,S .(1966).Network Classification, from
http://homepages.uel.ac.uk/u0212068/classification.htm