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C Programming Language

C language developed at Bell lab by Dennis Ritchie on UNIX environment. UNIX was later rewritten in C. An earlier version of C is BCPL (Basic Combined Programming Language) developed by Ken Thompson. When it was later improvised by Dennis, it became C (‘C’ from BCPL) programming language. C program could be written either in…

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Mobile Communication Services

One of the fastest growth rates in the telecommunications industry anywhere in the world is that of mobile radio communication devices. The basic architecture of such a mobile communication network is shown below –   Radio telephones or cell phones provide a switched two-way channel between two conversing parties like a conventional telephone. Telephones may…

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Digitized Phone Services (E-10B)

Olden form of phone systems involved manual exchanges which involved a great task in switching and routing of calls to various subscribers that increased network traffic and longer setup times. Also, fault checking and identification was very difficult. With the introduction of electronic exchanges which used a stored program concept of switching and routing of…

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Early Evolution of Data Commmunication Systems

It’s helpful for data communication and IT students to understand the evolution of Data communication systems. The first phase in the evolution of data communication systems was Telegraph Systems. Later, with developments in the telephone systems, it was then possible to interconnect various computer terminals for data communication. With the advancements in network computing and the…

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Data Communication and its basic setup

Data Communications is the function of transferring a digital signal from one digital device to another. Data transmission and data communications mean two different things. Data communication has a much wider meaning which embraces not just electrical transmission but, any other factors involved in controlling, checking and handling the movement in a communication-based computer system….

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Binary Tree

Binary Tree is a basic data structure that is used behind the scenes of all major technologies whether it’s a Database system or operating system, search engine, Bleeding edge AI systems, Big data or cloud based architectures.  

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Finding power transmitted by a pulley

Here is a real life mechanical problem to solve – Two parallel shafts whose center lines are 4.8m apart are connected on an open belt drive. The diameter of the larger pullet is 1.5m and that of the smaller pulley is 1.05m. The initial tension in the belt when stationary is 3KN. The mass of…

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ARP – Address Resolution Protocol

ARP or Address Resolution Protocol is used to map Internet addresses to physical addresses. Address resolution is the process of mapping Internet IP addresses into physical addresses. Two machines in the internet cannot communicate with each other  without knowing each others actual physical address i.e address of its hardware interface, for e.g. the network interface…

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Weaknesses of IP address

Below are couple major weaknesses of IP addresses – A machine cannot be assigned a permanent IP address i.e. it should change when the machine is connected to different physical networks When class C networks grow beyond 255 hosts, they  should be changed to class B networks. Such changes in IP addresses requires high labor,…

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Network & Broadcast address

Network and Broadcast address are derived from the general IP addresses and are used for specific or reserved applications. Network address refers to the IP addresses with all the bits in the host address 0s. The network address refers to the network itself. For e.g, a class A address 96.0.0.0 refers to the same class…

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Internet Addresses

Internet address refers to the unique identification or address assigned to each machine in the physical network. The basic need for assigning Internet address is to identify every machine in the network. Internet address is defined as the 32-bit (or 64 bit) address assigned to each machine on the internet so as to identify that…

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Internet Architecture

As shown above, the Internet consists of various physical networks (Net1 … Netn) connected together as a single large network. Each network may have host machines connected or other networks connected within it. G1 .. Gn represents the Gateways or routers that connects two networks. Gateways or routers routes data packets from a host in…

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Internetworking Concept and Architectural Model

Internetworking is the technology that makes it possible to interconnect many disparate physical networks with diverse underlying hardware technologies and make them function as a coordinated unit. The internetworking / Internet technology hides the details of network hardware and permits computers to communicate independent of their physical network connections. When we speak of interworking technology, we…

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ARPANET Technology

ARPANET (Advanced research project agency network) is the oldest wide area packet switched network build by the DARPA (Defense advanced research project agency). Physically ARPANET consisted of about 50 BBN corp’s C30 and C300 minicomputers called the PSNs (packet switching nodes) that were scattered over US and Europe. Each PSN was a dedicated packet switching…

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ProNET variation – Start topology

ProNET variation as star topology is as shown below – The 3 hosts are connected logically by a ring connection and physically by a start connection via a wire center. The wire center consists of relays R1, R2, R3, R4 so that the relays connects the corresponding host to the wire center via the interface….

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ProNET 10 Token recovery

ProNET 10 token recovery is essential to handle situations of loss of token when the host want to transmit. Such token loses occur due to malfunction or electronic interference that damages the token. To recover the token, we implement two timers at each station – flag timers and token timers. The flag timer is reset…

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ProNET Token Ring Technology

ProNET Token ring technology is an alternative to ethernet technology and it also works fairly good speeds. It uses token ring technology- Token ring network as shown above consists of hosts connected as a ring via wires that comes out of each host and connected to the other host. Each host in the network engage…