Dimensions of Computer Network

Dimensions of computer networks mean under what characteristics or factors can the computer networks be categorized. Computer networks can be divided into different groups under the pattern which recognizes the transmission of information or messages by the sender to the receiver and the area it covers for message delivery. 

Computer networks are divided into two dimensions:

1. Transmission technology 
2. Scale

These dimensions are further divided into sub-categories.

Classification of computer networks according to transmission technology:

1. Broadcast networks
2. Point-to-point networks

Broadcast Networks

Broadcast networks are networks that have a single sender and multiple receivers using a common transmission channel. Short messages sent by any sender are received by all others. An address field within the packet specifies to whom it is sent. The message is sent to all the receivers using their own transmission channel.

Broadcasting is a mode of operation in which a packet is sent to a number of receivers using a unique id in the address field. In Multicasting, the message is sent to the targeted or specific members of the network.

Point-to-Point Networks

It consists of many connections between individual pairs of devices. 

Two broadcast networks are:

• Bus
• Ring

Bus: When several devices are connected to a single cable of transmission then it is called a bus.

Ring: In Ring topology, there is a circular data path. Each of the devices is connected to two other devices in the network.

Broadcast networks can be, depending on how the channel is allocated, further divided into:

• Static – uses round-robin algorithms. It wastes channel capacity.
• Dynamic – Channel allocation could be centralized or decentralized.
  

Classification of Networks by Scale

We can note that the classification of the network can be defined by another factor which is the distance between the devices for the transmission of information. Distance is important as a classification characteristic because different techniques are used at different scales.

Local Area Network: Local area networks (LANs) are privately owned, within a distance of up to a few kilometers in size. They are differentiated from other kinds of networks by three characteristics:

1. Size
2. Transmission technology
3. Topology

LANs are restricted in size. LANs transmission technology often consists of a single cable to which all devices are attached. Traditional LANs run at speed of 10 to 100 Mbps. 

Metropolitan Area Network: A metropolitan area network (MAN) is a larger network than LAN. It might cover a group of nearby corporate offices or a city and might be either private or public. If LAN covers a school or office campus then MAN would cover a city or a group of offices.

Wide Area Networks: These cover a large geographical area, Establishing WAN would need transmission cables, routers, hosts, switches, etc.