Public Switched Telephone Network (PSTN) is an agglomeration of an interconnected network of telephone lines owned by both governments as well as commercial organizations. Properties of PSTN It is also known as Plain Old Telephone Service (POTS) It has evolved from the invention of telephone by Alexander ... Read More

Packet switching is a connectionless network switching technique. Here, the message is divided and grouped into a number of units called packets that are individually routed from the source to the destination. There is no need to establish a dedicated circuit for communication. Process Each packet in a packet switching ... Read More

The total bits in a number can be counted by using its binary representation. An example of this is given as follows − Number = 9 Binary representation = 1001 Total bits = 4 A program that demonstrates this is given as follows. Example Live Demo ... Read More

Improved Mobile Telephone System (IMTS) was a radio system that linked to public switched telephone networks (PSTN) before the era of cellular mobiles. It was introduced in 1964 and was the wireless equivalent of landline dial up telephones. Features IMTS was a radio system for mobile telephones that was ... Read More

A network interface device (NID), also called network interface unit (NIU), is an interface between the network provider's local loop and the customer. These are present as grey boxes outside customer's premises, where the data wires of the phone company or the network provider ends and the customer's wiring begins. ... Read More

Second generation (2G) mobile phones switched from analog system of 1G to digital system. It was commercially launched in 1991 as GSM standard in Finland. As with 1G phones, 2G phones didn’t have any worldwide standardizations. 2G systems were also known as personal communications services (PCM). Advantages of 2G over ... Read More

In U.S. telecommunications, Local access and transport area (LATA) refers to a geographical area in the U.S. which is allocated to telephone companies. The telephone companies, legally termed as local exchange carriers (LECs) provide telecommunication services, within the allotted areas. A LATA may be within the same U.S. state or ... Read More

Global System for Mobile communication (GSM) is the most widely used digital mobile telephony system. GSM technology was first launched in Finland in 1991. It was developed by European Telecommunications Standards Institute (ETSI) to describe the protocols for 2G mobile communications.Presently, GSM comprises of approximately 90% of mobile connections worldwide. ... Read More

The network data link layer is the layer above the physical layer in the Open System Interconnections (OSI) model. The primary concern of this layer is to convert the raw transmission facility provided by the physical layer to a reliable and error-free link.In TCP/IP model, the physical layer and the ... Read More

In the OSI (Open System Interconnections) Model, each layer uses the services of the layer below it and provides services to the layer above it. The primary function of the data link layer is to provide a well-defined service interface to the network layer above it. Virtual Communication versus ... Read More