Skip to main content

Communication Devices

Communication Devices

 The hardware used to transmit data, instructions and information between a sending and  receiving device is called communication device. A communication device at sending end sends data to a communication channel. A communication device at receiving end receives data from communication channel. Some communication devices are as follows: 

Modem
Modem stands for modulation and demodulation. Modem is a device that converts digital signal into analog  and analog signal into digital. Modem sends and receives data from one computer to another  through telephone lines. The sending and receiving computers both must have modems. A process of converting digital signal is called modulation. Computer stores data using telephone line, so it is converted from digital to analog form. A process of converting analog signal into digital signal is called demodulation. The modem on receiving computer receives data in analog form and converts it into digital format to be used by the computer.
Network Interface Card
Network Interface Card (NIC) is also called LAN adapter. It is used to connect a devices to a network. The transfer rate of an Ethernet card is from 10 Mbps to 1000 Mbps to 1000 Mbps. Different NIC are available for different types of computers. Network cards for wireless data transmission are also available. These adapter cards often have an antena.


Wireless Access Point
 A wireless access point is a central communication device. It allows computer and other devices to transfer data wirelessly among themselves or to a wired network.Wirless access points have high quality antennas for optimal signals. Some manufactures suggest to place the wirless access point at the highest possible location for the best signal.




Routers
A router is a communication device that connects multiple computer or other routers together. It connects multiple networks using similar or different protocols. It manages the best route between any two communication networks. Routers are used when several networks are connected together. They can connect networks of different countries. They transfer data in less time. The router is an intelligent device. It uses algorithms to find out the best path to transfer data to network.

HUB
A hub also called concentrator or multistation access unit (MAU). It provides a central point for cables in a network. Hubs also transmit signals and have multiple ports to which devices are connected. It broadcasts all messages to every computer on the network but only the intended recipient  computer takes the message.The computer that are not the recipients of the message ignores the message.A hub can handle only one-way  information traffic at a time.         

Comments

Post a Comment

Popular posts from this blog

Pointers in C

Pointers are an extremely powerful programming tool. They can make some things much easier, help improve your program's efficiency, and even allow you to handle unlimited amounts of data. For example, using pointers is one way to have a function modify a variable passed to it. It is also possible to use pointers to dynamically allocate memory, which means that you can write programs that can handle nearly unlimited amounts of data on the fly--you don't need to know, when you write the program, how much memory you need. Wow, that's kind of cool. Actually, it's very cool, as we'll see in some of the next tutorials. For now, let's just get a basic handle on what pointers are and how you use them. What are pointers? Why should you care? Pointers are aptly name: they "point" to locations in memory. Think of a row of safety deposit boxes of various sizes at a local bank. Each safety deposit box will have a number associated with it so that you ca...
30 comments
Read more

Types of Computer Networks(LAN,MAN,WAN)

Types of Computer Networks Computer networks are categorized according to: How they are organized physically. The way they are used. The distance over which they operate. Three main types of computer networks are as follows: LAN   (Local Area Network) WAN (Wide Area Network) MAN ( Metropolitan-Area Network) LAN (Local Area Network) LAN is the most common type of network . LAN stands for Local area Network . It covers a small area. Most LANs are used to connect computers in a single building or group of buildings. Hundreds or thousands of computer maybe connected through LAN. Typical LANs can be found in industrial plants, office buildings, and college or university campuses. LANs are capable of transmitting data at very fast rate. Data transmission speeds of LAN are 1 to 100 megabits per second. It is much faster than data transmission over a telephone line. LAN can transmit data in a limited distance. There is also a limit on the number of...
9 comments
Read more

Ring topologies

Ring topologies are similar to bus topologies, except they transmit in one direction only from station to station. Typically, a ring architecture will use separate physical ports and wires for transmit and receive. Token Ring is one example of a network technology that uses a ring topology.
7 comments
Read more