The physical structure of a network refers to the way in which the network elements are connected. Transmission technology is an important aspect which directs the design of the network.
Transmission Technology:
It refers to the way in which two devices can be connected. There are two types of transmission technologies in use today:
1. Point-to-Point
2. Broadcast
Point-to-Point connection provides a dedicated link between two devices. The full capacity of the link is reserved for transmission between those two devices. Thus, in a point-to-point network, data packets may have to visit one or more intermediate machines to move from source to destination. The link between two devices or machines can be a physical cable or wireless media such as a microwave or satellite link.
Broadcast: These networks have a single communication channel that is shared on all networks by machines. Such connections are also called multipoint or multi drop connections. In a broadcast system, a packet sent by a machine is obtained by all others.
It is also possible to transmit data to network subsets (multicasting). Point-to-point transmission with a sender and a receiver is called Unicasting.
Typically, geographically localized networks (small networks) use broadcasting while large networks are usually point-to-point.
