introduction to DATA COMMUNICATION

Advancements in the information technology sector have brought many benefits to the people all around the world.  Today with computer networking, we can chat, speak and see each other over a long distance. Data communication refers to the transmission of the digital signals over a communication channel between the transmitter and receiver computers. Communication is possible only with wired and wireless connectivity of the computers with each other.
All the computers, in the logically and physically networks have to follow the same rules known as Protocols such as TCP/IP, IPX/SPX and NETBEUI etc. Today, there are many computer networking technologies such as LAN, MAN, WAN, WLAN, ISDN, ATM, Frame Relay, X.25, Bluetooth, GPRS, CDMA and many others.
There are different types of the physical medium that allows the communication between the network devices such as UTP, STP, Fiber optic, coaxial cable, Microwave, radio frequencies, satellite and electromagnetic waves.  The devices that are involved in the data communication process are LAN cards, hub, router, switch, CSU/DSU and modems.  Following elements are involved to form a network communication system.

• Computers
• Protocols
• LAN Card
• Hub/Switch/Router
• Mediums (UTP/STP, Fiber optic cables, Air)

Protocols are the set of rules, agreed upon ways and standards that are used to make data transmission process.  Every computer in a network should support the same protocols.  TCP/IP is the most common communication protocol in the LAN, WAN and on internet. With the advancements in the communication technologies data, voice and video signals can be transmitted over the same channel such as broadband internet.


Every computer network exists in a topology, which means physical design or layout of a network.  The common network topologies include star, mesh, bus, ring, hybrid and tree.  The star topology is the most commonly used topology in the Ethernet network.

Every message in the transmission process is divided into the seven logical layers known as the OSI layers model.  Security and privacy are the biggest concerns in the data communications. Wireless networks, faxed business letters and the computer without proper security implementations can be hacked. To deal with these internal and external security threats the data communication networks should be properly safe guarded with the antivirus, antivirus and firewall solutions.  Computer networks should also meet the performance, reliability, consistency, recovery and security criteria to maintain the smooth flow of data in an organization.