Modem is an abbreviation of “modulator demodulator”. It is a network device that modulates digital information or bits into analog signals for transmission at the sending end, and demodulates the analog signals to bits at the receiving end. Telephone modems enables data communication between two computers over voice – grade ... Read More

Two variables can be swapped in one line in Java. This is done by using the given statement. x = x ^ y ^ (y = x); where x and y are the 2 variables. A program that demonstrates this is given as follows − Example Live ... Read More

Wireless cellular technology or mobile communications started with first generation mobile phones, popularly known as 1G. It was an analog telecommunications system, introduced in 1979 and continued to mid of the 1980s. History 1G mobile communication system was introduced in Japan in 1979 by Nippon Telegraph and Telephone (NTT). Initially, ... Read More

Data over cable service interface specification (DOCSIS) is an international telecommunications standard to provide high speed data to cable TV system over its existing hybrid fiber-coaxial (HFC) infrastructure. It is used for providing cable Internet access as well as supporting high definition televisions. Versions of DOCSIS DOSCIS 1.0 − ... Read More

Definitions Circuit Switched Networks − Circuit switched networks are connection-oriented networks. Here, a dedicated route is established between the source and the destination and the entire message is transferred through it. Packet Switched Networks − Packet switched networks are connectionless networks. Here, the message is divided and grouped into a ... Read More

Frequency division duplex (FDD) is a communication technique where the connected parties can communicate with each other in both directions through use of separate frequency bands for transmitting and receiving. Since FDD uses different frequency bands for upstream data and downstream data, the sending and the receiving signals do ... Read More

Definitions Cable − Cable network is a system of providing varied services like television programming, FM programming, Internet and telephone services over existing cable TV network. ADSL − Asymmetric Digital Subscriber Line (ADSL) is a type of broadband communications technology to transmit digital data at a high bandwidth on existing ... Read More

Digital Advanced Mobile Phone System (D-AMPS)is a digital version of Advanced Mobile Phone Systems (AMPS), the original analog standard for cellular phones. D-AMPS uses a combination of time division multiple access (TDMA) and frequency division multiple access (FDMA). It adds TDMA to get three channels per AMPS channel, thus tripling ... Read More

The network physical layer is the lowest network layer in the Open System Interconnections (OSI) model. The primary concern of this layer is transmission of individual bits from one node to another over a physical medium. In TCP/IP model, the physical layer and the data link layer are combined as ... Read More

The data link layer in the OSI (Open System Interconnections) Model, is in between the physical layer and the network layer. This layer converts the raw transmission facility provided by the physical layer to a reliable and error-free link. The main functions and the design issues of this layer are ... Read More