Basics of Data Communication

By the help of direct, two-level electrical signals over simple copper conductors, the digital data can be transmitted. These types of transmission are needed as the distance over which data moves within a computer may vary from a few thousandths of an inch. In this case within a single IC chip, to as much as several feet along the backplane of the main circuit board, the help of copper conductors are utilized. The circuit designers are not concerned about the shape of the conductor or the analog characteristics of signal transmission except for the fastest computers.

The data should be sent beyond the local circuitry that constitutes a computer. The distances involved may be enormous in many applications. As the distance between the source of a message and its destination increases, efficient transmission of data becomes increasingly difficult. This is mainly due to the electrical distortion of signals occurs while traveling through long conductors and from noise added to the signal as it propagates through a transmission medium, which is generally called as the Channel in a communication network. The biggest challenge occurs when the data is transferred to devices outside the computer’s circuitry. In such applications, the distortion and noise influenced through the channel can become so severe that information may be lost.

The transmission of digital messages to devices external to the message source, Data Communications is mainly concerns. The maximum permissible transmission rate of a message is directly proportional to the signal power and is inversely proportional to channel noise. The aim of any communications system is to provide the highest possible transmission rate at the lowest possible power and with the least possible noise. In other words, the task of a communication is to increase the data (signal) strength and to minimize the noise content. This can be represented by the Signal to Noise ratio (SNR). The aim of any communication network should be to maximize the SNR strength. Here Maximizing the SNR will leads to the minimization of the noise content.

Serial Communications:

Most digital messages are greatly longer than just a few bits. Since it is neither practical nor financial to exchange all bits of a long data at the same time, the data is broken into smaller parts and passed on sequentially. Bit-serial transmitting provides a one bit data at some point through a route in transmitter-receiver link. Each bit symbolizes a part of the data. The individual pieces are then put back together at the destination to restore the data. In general, one route will pass only one bit at some point. Bit-serial transmitting is usually called serial transmitting and is the most chosen transmission method in many computer peripheral devices.

The byte-serial transmitting provides eight pieces at some point through eight similar channels. Although the raw exchange rate is eight periods faster than in bit-serial transmitting, eight channels are needed, and the cost may be as much as eight periods higher to deliver the data. When ranges are short, it may however be both feasible and financial to use similar programs in return for high information rates. The popular Getronics printer interface is a case where byte-serial transmitting is used. As another example, it is common practice to use a 16-bit-wide information bus to exchange information between a micro-processor and memory chips; this provides the equivalent of 16 similar programs. On the other hand, when interacting with a time period

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Different Types Of Data Communication Media

The process in which data is transferred from one computer to another is known as communication media. Data communication involves transmission of digital of information to different electronic devices through wireless or cabled connections. The two commonly used computer communication media used are bounded and unbounded media.

A. Bound Media

Data transfer through physical connections is referred to as bounded media in that signals are sent to other external devices from one computer in a network. Computers can be interconnected to share files and devices in a network by means of cabling which facilitates faster communication of information. Bounded media is a faster data communication that provides high speed transfer of signals over long distances and is the most reliable media for message sending.

Bounded media is categorized into three types of data communication which enables connection of different types of network. These cables include:

1. Coaxial cable

This is most common bounded media that is many electronics to transfer data and it is designed with two parallel copper conductors. It has a solid central copper conductor that transmits signal and is coated with a protective cover to reduce electromagnetic interference. Coaxial cable is found in different gauges at affordable prices and is easier to work with. They are easy to install and can support up to 10Mps capacity with medium attenuation. Despite its popularity, the only serious drawback it has is that the entire network is always affected with a single cable failure.

2. Twisted pair cable

Twisted pair cables are found in two types and these include unshielded and shielded twisted pair cables. It is commonly used because it is lighter and inexpensive. They are made up of twisted solid copper wires which help to reduce vulnerability to EMI and cross talk effects. This type of cables is cheaper and can support up to 100mps speed capacity.

3. Fiber optic

Unlike other types of cables, fiber optic uses electrical signals for communication and is made up of reflective cladding that prevents loss of light in the glass core. Although it very expensive and hard to install, optic cables can support at least 2gbps and are not vulnerable to EMI interference. It has got also very fast data transmission and very low attenuation compared to other data cables.

B. Unbounded media

This type of data communication media involves networking of multiple computers through a wireless connection. Creating a wireless connection is much easier since no physical connection is required and can connect multiple computers in a room. Unbounded media uses space or air as the transmission medium for electronic waves. Some of the unbounded media are the satellites, radio, Bluetooth and Wi-Fi among others. Installation of wireless network is much easier and faster compared to the bounded media which require an expert to do the configuration. Through wireless settings, you can also transfer huge files of data to any networked computer since the unbounded media supports very high bandwidths just like the cabled network.

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