‘Computer Network’ means an interconnected collection of autonomous computers. Two computers are said to be interconnected if they are able to exchange information. The connection need not be via a copper wire, fiber optics, microwaves & satellites can also be used.
Types Of Transmission Technology :
There are Two types of Transmission Technology :
- Broadcast Networks
- Point – To – Point Networks
I . Broadcast Networks
Broadcast Networks have a single communication channel that is shared by all the machines on the Network. Short messages called packets in certain contain contexts, sent by any machine are received by all the others. Broadcast System generally also allow the possibility of addressing a packet to all destination by using a special code in the address field. When a packet with this code is transmitted, it is received & processed by every machine on the network. This mode operation is called broadcasting.
II. Point – To – Point Networks
Point – To – Point networks consists of many connections between individual pairs of machines. To go from the source to the destination, a packet on this type of network may have to first visit one or more intermediate machines. Often multiple routes of different lengths are possible, so routing algorithms play an important role in point – to – point networks.
An alternative criterion for classifying networks in their scale.
Local Area Network
Wide Area Network
Local Area Networks
Local Area Networks generally called LANs. LANs are privately owned networks within a single building or campus of up to few kilometers in size. LANs are widely used to connect personal computers & workstations in company offices & factories to share resources & exchange information. LANs has three characteristics such as
- Their Size
- II. Their Transmission Technology
- III. Their Topology
LAN often use a transmission use a transmission technology consisting of a single cable to which all the machines are attached like the telephone company party lines once used in rural areas. Traditionally LANs run at 10 to 100 Mbps speed, have low delay& make very few errors.
Various topologies are possible for broad cast LANs, such as Linear cable or cable &other is Ring topology