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Duplex (telecommunications)
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX). In a full-duplex system, both parties can communicate with each other simultaneously. An example of a full-duplex device is plain old telephone service; the parties at both ends of a call can speak and be heard by the other party simultaneously. The earphone reproduces the speech of the remote party as the microphone transmits the speech of the local party. There is a two-way communication channel between them, or more strictly speaking, there are two communication chann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication System
A communications system or communication system is a collection of individual telecommunications networks, transmission systems, relay stations, tributary stations, and terminal equipment usually capable of interconnection and interoperation to form an integrated whole. The components of a communications system serve a common purpose, are technically compatible, use common procedures, respond to controls, and operate in union. Telecommunications is a method of communication (e.g., for sports broadcasting, mass media, journalism, etc.). Communication is the act of conveying intended meanings from one entity or group to another through the use of mutually understood signs and semiotic rules. Types By media An optical communication system is any form of telecommunication that uses light as the transmission medium. Equipment consists of a transmitter, which encodes a ''message'' into an optical '' signal'', a '' communication channel'', which carries the signal to i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called ''cellular telephones'' or ''cell phones'' in North America. In addition to telephony, digital mobile phones ( 2G) support a variety of other services, such as text messaging, multimedia messagIng, email, Internet access, short-range wireless communications ( infrared, Bluetooth), business applications, video games and digital photography. Mobile phones offering only those capabilities are known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITU-T V-Series Recommendations
The ITU-T V-Series Recommendations on Data communication over the telephone network specify the protocols that govern approved modem communication standards and interfaces. ''Note:'' the '' bis'' and '' ter'' suffixes are ITU-T standard designators of successive iterations of a standard (''bis'' and ''ter'' are derived from the Latin for "twice" and "thrice"). General standards ''Applies to V.1–V.9'' *V.1 is an ITU-T recommendation, entitled ''Equivalence between binary notation symbols and the significant conditions of a two-condition code.'' *V.2 is an ITU-T recommendation, approved in November 1988, titled ''Power levels for data transmission over telephone lines.'' *V.4 is an ITU-T recommendation, approved in November 1988, titled ''General structure of signals of International Alphabet No. 5 code for character oriented data transmission over public telephone networks.'' *V.5 was an ITU-T recommendation, approved in November 1988, titled ''Standardization of data signal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
