Communication equipment transmits or receives information over a distance by electrical or electromagnetic medium in a variety of forms such as radio, telegraphy, television, telephony, data communication and computer networking. Communication systems support wireless and wire-lined communications between wireless and/or wire-lined communication devices. Such communication systems range from national and/or international telephone or cellular phone systems to the Internet to point-to-point in-home wireless networks. The telephone networks enable communication across great distances becoming possible. The utilization of cellular phones (mobile phones) is becoming increasingly popular in today's wireless environment. Wireless connectivity technology allows the replacement of a number of proprietary cables that connect one device to another with a universal short-range radio link. Business and consumers use a wide array of wireless devices, including cell phones, wireless local area network (LAN) cards, global positioning system (GPS) devices, and electronic organizers equipped with wireless modems operates, in accordance with one or more communication standards. For instance, wireless communication systems, that operate in accordance with various standards including IEEE 802.11, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), and multi-channel-multi-point distribution systems (MMDS). Wireless communications involve the transmission and reception of data packets and other types of information via wireless, cellular and/or mobile techniques. Cellular communication networks are rapidly becoming a primary infrastructure for enabling communication in today's society.
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Saturday, 20 January 2007 |
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The use of a power line as a communication channel provides a remarkable advantage in that additional expenses are not required for the construction of a new communication channel. Creation of data paths may be accomplished simply by plugging the distributed terminals into any available alternating current (AC) outlet. A basic PLC system consists of a transmitter unit capable of adding the communication signal to the AC power line signal and a receiver unit capable of separating the communication signal from the AC power component signal. Powerline communications offers end users a broad spectrum of applications and services, which imay include broadband Internet access, voice over Internet protocol (VoIP), multimedia services, home automation and energy management. |
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Sunday, 14 January 2007 |
Speakerphones are telephone terminal devices which permit a user to converse over a telephone network with another party without the use of a handset. A speakerphone offers the advantage of hands-free telephoning by replacing the familiar handset with a separate microphone and loudspeaker. The speakerphone includes a speaker for converting electrical signals representative of speech to audible sound, and a microphone for converting an audible input such as speech to electrical signals. Speakerphones may be designed to operate in either half-duplex or full-duplex mode. Mobile phones often include a speakerphone mode in which users can use the phones in a hands-free configuration without the use of headsets. Another major use of speakerphones is in conference calls.
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Sunday, 07 January 2007 |
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Voice mail systems (VMS, voice messaging systems) are used for answering telephone calls directed to a person who is unavailable. A voice mail system is a specialized computer or network of interconnected computers. Voice mail systems attach to the telephone network, often via a PBX, and store messages from incoming calls when the intended recipient is absent or otherwise engaged. The voice message is digitized and stored in compressed form on a hard disk that maintains the voice mail operating system, system prompts, and greetings, and the messages themselves. In a network-based voicemail system, the voicemail system is operated remotely from the subscriber's telephone and is a part of the overall telecommunications network in which the subscriber's telephone operates. |
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Thursday, 21 December 2006 |
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Key telephone systems are phone switching system for relaying telephone communication between extensions or between an extension and an outside phone. A basic key telephone system includes a number of key telephone sets connected through a central control unit to each of a number of key telephone sets. Each key telephone includes a number of subscriber lines connected thereto. The main unit containing a plurality of key telephones is connected to an office line or a public switched telephone network. Data including speech data and control data are transmitted between the key telephone and the main unit in a predetermined data transmission scheme which depends on the system. A digital key telephone system include digital key telephones connected to the extension lines of the main unit. |
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Friday, 15 December 2006 |
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An automated attendant system is a call processing system used to automatically process incoming telephone calls. Automated attendants have become very popular for business applications. Many business organizations use automated attendants to connect an outside caller through a telephone company central office to an extension of a telephone switching system. Auto attendant systems can be implemented from a telephone system central office or in customer premises telephone systems with a private branch exchange (PBX). Automated telephone answering systems have been employed to off-load work from live operators to the callers. The caller enters information using touch tones or the caller's voice. The computer analyzes customer input information and completes certain commands. |
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Friday, 08 December 2006 |
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Telephone call centers are call management systems that distribute phone calls. An automatic call distributor receives incoming calls, distributes the incoming calls to operator workstations or to voice response units, and produces information that is valuable to call center managers. Data processing systems and computer networks are employed in call centers to aid in the exchanges between the agents and the consumers. Sophisticated call centre software may filter calls through interactive voice response (IVR) menus to enable certain queries processed automatically and appropriately. Call centers are widely used to provide services in both the commercial and governmental sectors. Call centers are used for reservation centers, sales calls, customer services, and technical support. |
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Saturday, 02 December 2006 |
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Private branch exchanges are switching devices used by organizations with a need for internal telephone communication and for routing telephone calls from external telephone lines to internal telephones. A PBX system generally provides telephone usage information such as call start time, call duration, and call charge when an extension subscriber communicates with an external subscriber through an office line. A PBX phone system allows an entity to efficiently provide access to communication services without necessarily having dedicated telephone lines. A PBX is connected via a direct inward dial (DID) trunk to a switching system of the wired network. The PBX itself is a private self-regulated switching unit that provides its subscribers with features like those found in public networks. |
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Friday, 17 November 2006 |
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Users of personal computers and other digital devices have been able to engage in voice communications using these devices for many years. Voice communication over the Internet works by using the internet connection rather than the telecommunications network. In an internet communication system, analog voice signals are initially digitalized, encoded, and transmitted in forms of voice data packets by a transmitter. A receiver then receives the voice data packets sent, converts them to analog signals, and outputs the analog signals through a speaker. Calls are routed through a packet switched internet protocol network. Packet networks are more economical than circuit switched networks. VoIP technology supports audio, video, data, or fax communications using the internet protocol. |
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Sunday, 12 November 2006 |
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Voice over IP (VOIP) is the technology used to transmit voice messages over a data network using the Internet Protocol. Voice over Internet protocol (VOIP) telephony systems transmit voice-band calls over a packet data network, such as a corporate intranet or the Internet. Information is transmitted over an Internet Protocol (IP) network in asynchronous packets. Calls are first accepted based on a user profile and, once the destination is selected, all voice traffic is packetized in IP and transmitted. VoIP transmission typically costs less than transmission over traditional public switched telephone networks. Packet-based networks are rapidly emerging as a viable alternative to traditional telephony. VoIP allows live voice conversations to be integrated with existing IP data and image applications. |
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Thursday, 26 October 2006 |
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An intercom, short for intercommunicating telephone, is a communication system linking different rooms within a building or different places. Intercom systems provide communication between two or more remotely located individuals. Intercom systems are used in a variety of commercial contexts to provide communication between two or more individuals located remote from one another. A vehicle voice enhancement system uses intercom systems to facilitate conversations of passengers sitting within different zones of a vehicle. The conference-type intercom systems include a crosspoint switch which allows any user to communicate with any selectable mix of the remainder of the users. A modern home potentially has a great number of sophisticated electrical systems, including intercom systems. |
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Thursday, 19 October 2006 |
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A fax machine transmits a document by producing a graphic image of the document which is converted into a data signal. The data signal is transmitted over conventional phone lines to a receiving fax machine which uses the data signal to drive a printer portion of the receiving fax machine to print an image of the document. Facsimile machines operate by encoding an image on a paper into a series of tones that are then transmitted over the telephone network to a receiving facsimile machine. A facsimile machine generally comprises an image reader for reading images on the original as image information, a printer for printing the read image information on paper, and a transmission-reception device. The image reading unit of a facsimile transmitter typically employs a CCD image sensor. |
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Monday, 09 October 2006 |
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A telephone answering machine, which may be called an answering system or an answering machine, is an electronic device that automatically answers an incoming telephone call, plays a pre-recorded message, and records a message that the caller leaves. A telephone answering system responds to an incoming telephone call, as by playing a prerecorded message, and offers the caller the option of recording an audio message. A telephone with an answering function or mode which automatically records the message of a caller on a recording medium like a cassette tape or an endless tape when nobody is available to answer the telephone. A digital answering machine is used to answer a telephone and store voice messages in an internal solid state memory rather than on magnetic tape. |
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Friday, 22 September 2006 |
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Video telephony refers to visual communication using both video and audio transmitted over a communications network. A videophone is a system for bidirectionally transmitting moving pictures and speech of minimum quality over conventional telephone lines. Video telephones are used in communication systems to provide a two-way audio and video communications link. Video telephones typically consist of a video image capturing device, a standard video display unit, and the appropriate circuitry to provide video and audio communication between two like devices over a standard telephone line. The data compression techniques are used to compress audio and video signal for the information to be sent within the bandwidth constraints of conventional telephone lines. |
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Friday, 15 September 2006 |
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Two-way radios, or acknowledge-back paging systems, generally broadcast directly from one communications device (typically a portable radio) to another. Two-way radio communications are generally carried out using an associated pair of frequencies within one or more bands. Two-way systems provide confirmation of message delivery, as well as automatic retry upon a failure of a message delivery attempt. Portable two-way radios are used to communicate with extremely complicated communication systems which automatically switch operating frequencies and signalling protocols. Trunked radio systems utilize a central control unit to organize and control the operation of the entire system. Portable two-way radios are becoming more advanced in both form and function. |
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Sunday, 03 September 2006 |
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A camera phone is a combination of a cellular telephone and a camera in a single housing. The mobile terminal device provided with a digital camera has an image-information transmitting and receiving function in addition to a conventional voice-information and text-information transmitting and receiving function. Camera phones comprise a mobile, hand-held telephone and a digital camera in the same physical package. Digital camera lenses are added as a feature on cellular telephones to allow users to communicate and exchange information through pictures. A cell phone with an electronic camera has a built-in taking lens and a viewfinder. The camera lens module comprises an image sensor provided on a printed circuit board and a lens holder fitted with an infrared filter. |
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Wednesday, 30 August 2006 |
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A cordless telephone refers to a phone handset in which electromagnetic radiation is utilized to carry communications to and from the handset. Cordless telephones provide greater flexibility than traditional landline phones by permitting a user to move freely and not be physically restricted by a telephone cord. The primary benefit of the cordless phone is that the handset need not be at a fixed location and need not be located close to the base unit. A typical cordless telephone is comprised of a base unit or base station and a portable handset unit which both have antennas and transceivers for communicating with each other. The handset is capable of receiving and transmitting signals over a wireless link to the base unit. Cordless telephone handsets also typically include a microphone and a speaker. |
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Monday, 21 August 2006 |
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Wireless communication networks allow large amounts of voice and data information to be conveniently transferred and exchanged. A cellular phone or mobile phone is battery-driven electronic communication terminal, which incorporates a battery in a main body to supply operating power needed by an electronic circuit. Cellular phones have gained widespread acceptance due to their portability, versatility, and inexpensive price. A cell phone is not only capable of communicating by voices but also capable of transmitting messages. The digital camera added as a feature on cellular telephones allows users to communicate and exchange information through pictures. Cellular phones have liquid crystal display devices for receiving and transmitting symbol data. The battery of a mobile phone is typically a flat type. |
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Communication Equipment
