Improvement in communication technology since last decades has resulted in scalable, reliable and flexible computer network system. The computer communication is increasing so need to develop architecture that will be help to make communication proficient as well reliable. The computer communication is totally dependent on the price, how economical it is as well the speed performance.
The basic two architecture that are used I computer communication are the tightly coupled system and second is loosely coupled system.
Both architectures are explained in short below.
1. Tightly coupled system
- In this system basic difference is that each processor shares the common memory.
- Even they share bus, clocks, and input.
- Each processor is dependent on shared memory for processing and connected to the memory via bus .this is common bus which connects all the processors.
2. Loosely coupled system
- The loosely coupled system is called distributed system.
- In this type of system each processor has own memory that is called local memory.
- This process or hence do not share memory as like that of loosely coupled system.
- This system processor can communicate with each other using message passing.
Concept of distributed system
Distributed systems are those in which each independent computer is connected to each other via communication channel . This different connected computer appear to user as single computer. This concept can be explained in number of ways, hardware and software system connected to each other via communication medium to provide different services to the remote located end user.
In simple way to understand distributed system is autonomous computer are connected to each other via communication channel. They appear to user as single system. Why there is need of building distributed system or advantage of distributed system.
The distributed system are reliable example if any of processor crash while working you need not worry as there are multiple processor that can perform your job.
You remote from one location to another each time carrying huge data is not possible so distributed system provide you your data in no time.
As there are many processors and each one can perform task independently of other hence performance is quite better as compared to tightly coupled system.
The meaning of incremental is we can add new nodes, processor to the existing word. It also provides accessibility.
Disadvantage of distributed system
It is quite difficult to develop distributed software
It is very difficult which programming language should be used to design network.
Several problems are created when we are using infrastructure, there may be loss of messages, overloading etc.
Data security is very much important in any kind of network, it generates problem of data security.
In case of distributed system, the computing power required at each node is very much.
The reliable communication is need of today this communication can be made easy with help of loosely coupled or distributed system, the nodes at different location can communicate at different location in a efficient and effective manner.