ISDN, though not popular in US, it is still one of the most popular data communication networks in UK, India and many other European countries. ISDN evolved from the IDN (Integrated Digital Network) in which both the transmission media and switches employs digital techniques. In this system, speech signals are converted to digital signal at…
One of the fastest growing telecommunication industry is obviously mobile radio communication. Below figure shows a basic architecture of such a mobile communication network – Radio telephones or cellphone, as they are generally called, provides a switched two way channel between two conversing parties like a conventional telephone. Telephones may be in vehicles which can…
In the past, we had manual exchanges which involved a great task in switching and routing of calls to various subscribers that increased network traffic and longer setup times. Also fault checking and identification was very difficult. Now, with the introduction of electronic exchanges which uses a stored program concept for switching of calls and…
Almost all of the Data communication systems across the world evolved from Telegraph systems. Later with developments in the telephone systems, it was now possible to interconnect various computer terminals for data communication. With the advancements in the network computing and the digitization of telephone networks, it was now possible to setup an efficient data…