COMMUNICATIONSin computers, describes a process in which one computer transfer data, instructions, and information to another computer.
COMMUNICATIONS REQUIRES:1. SENDING DEVICE – a device thatinitiates the transfer.2. COMMUNICATION CHANNEL – provides the pathway over which the message can travel from source to destination.
COMMUNICATIONS REQUIRES:3. RECEIVING DEVICE – a device thataccept the sent material.
USES OF COMPUTER COMMUNICATIONSE-MAIL (ELECTRONICMAIL) – the exchange of textmessages andcomputer files via acommunicationsnetwork.
USES OF COMPUTER COMMUNICATIONSVOICE MAIL– an answeringmachine but convertsan analog voicemessage into digitalform.
USES OF COMPUTER COMMUNICATIONSFAX (facsimile)machine- sends and receivesdocuments viatelephone lines
USES OF COMPUTER COMMUNICATIONSTELECOMMUTING– allows employees towork away from thestandard workplace andcommunicate usingsome communicationstechnology.
USES OF COMPUTER COMMUNICATIONSVIDEOCONFERENCING– involves using video andcomputer technology toconduct a meeting betweenparticipants at two or moregeographically separatelocations.
USES OF COMPUTER COMMUNICATIONSGROUPWARE- is a softwareapplication that helpspeople work togetherand share informationover a network.
USES OF COMPUTER COMMUNICATIONSBBS (BULLETINBOARD SYSTEM)- a computer thatmaintains a centralizedcollection of electronicmessages.
USES OF COMPUTER COMMUNICATIONSGPS (GLOBALPOSITIONINGSYSTEM)– consist of earth based• receivers that analyze satellite signals to determine the receiver’s geographic location.
USES OF COMPUTER COMMUNICATIONSINTERNET – a worldwidecollection of networks.
COMMUNICATIONS CHANNELis the communications path between twodevices; this is composed of one or moretransmission media.
TRANSMISSION MEDIA• is consists of materials or techniques capable of carrying one or more signals, this is composed of – two types: • the physical • wireless transmission media
2 TYPES OF TRANSMISSION MEDIA1. PHYSICAL TRANSMISSION MEDIA – use wire, cable, and other tangible materials to send communications signals, these include:
2 TYPES OF TRANSMISSION MEDIAa) TWISTED PAIR CABLE - often used intelephone networks and LAN. b) COAXIAL CABLE – data travelsthrough the copper wire. c) FIBER-OPTIC CABLE – use light totransmit signals.
2 TYPES OF TRANSMISSION MEDIA2. WIRELESS TRANSMISSION MEDIA -send communication signals through theair or space using radio, microwave andinfrared signals, these include:
2 TYPES OF TRANSMISSION MEDIAa) BROADCAST RADIO - for radios/television.b) CELLULAR RADIO - for mobile communications/cellular telephones.c) MICROWAVES - radio waves that provide high speed signal transmission.
2 TYPES OF TRANSMISSION MEDIA d) COMMUNICATIONS SATELLITE - aspace station hat receives microwavesignals from an earth based station. e) INFRARED – sends signal usinginfrared light waves.
TRANSMISSION CHARACTERISTICStransmission sent during communicationscategorized in these characteristics:1. SIGNAL TYPE A) analog B) digital C) broadband D) baseband
TRANSMISSION CHARACTERISTICS2. TRANSMISSION MODES A) asynchronous transmission B) synchronous transmission
TRANSMISSION CHARACTERISTICS3. TRANSMISSION DIRECTION A) simplex transmission B) half-duplex transmission C) full duplex transmission
TRANSMISSION CHARACTERISTICS4. TRANSFER RATES A) Bandwidths – range of frequencies that a transmission can carry.
TELEPHONE NETWORKthe public switched telephone network (PSTN) isthe worldwide telephone system that handlesvoice communication and also an integral part ofdata communications, sending data via thetelephone network travel over a variety oftransmission media and can be sent using dial-up lines or dedicated lines.
TELEPHONE NETWORKDIAL-UP LINES - dial-up line is atemporary connectionthat uses one or moreanalog telephone linesfor communications.
TELEPHONE NETWORKDEDICATED LINES– connections that alwaysestablished between twocommunications devices, itprovides constant connection.Businesses can buy or leaseddedicated line from telephone orcommunications ServiceCompany.
4 POPULAR TYPES OF DIGITAL LEASED LINES1. ISDN (Integrated Services DigitalNetwork) LINES– is a set of communication standards forsimultaneous digital transmission of voice, video,data, and other network services over thetraditional circuits of the public switchedtelephone network.
4 POPULAR TYPES OF DIGITAL LEASED LINES1. ISDN (Integrated Services DigitalNetwork) LINES
4 POPULAR TYPES OF DIGITAL LEASED LINES 2. DIGITAL SUBSCRIBER LINES(DSL)- uses broadband to transmit a greater number ofbytes on a standard twisted-pair cable. o Some of the DSL installations can provide a dial tone so you can use the line for both voice and data.
4 POPULAR TYPES OF DIGITAL LEASED LINES2. DIGITAL SUBSCRIBER LINES (DSL)
4 POPULAR TYPES OF DIGITAL LEASED LINES3. T-CARRIER LINES- is any of several types of digital lines thatcarry multiple signals over a singlecommunications.
4 POPULAR TYPES OF DIGITAL LEASED LINES3. T-CARRIER LINES
4 POPULAR TYPES OF DIGITAL LEASED LINES4. ASYNCHRONOUS TRANSFER MODE (ATM)- is a service designed to carry voice, data,video, and multimedia at high speeds -currently up to 622 Mbps.
4 POPULAR TYPES OF DIGITAL LEASED LINES4. ASYNCHRONOUS TRANSFER MODE (ATM)
COMMUNICATIONS SOFTWARE- that makes it possible to send and receive data over telephone lines through modems. - that manage the transmission of data, instruction, and information between computers. - helps users establish a connection to another computer or network. - provide an interface for users to communicate with one another.
COMMON TYPES OF COMMUNICATION DEVICEMODEM- device that perform conversion in digital signals and analog signals, it can be internal or external. - Both the sending and receiving ends of a communications channel must have a modem for data transmission to occur.
COMMON TYPES OF COMMUNICATION DEVICECABLE MODEM– a modem that sends and receives dataover the cable television (CATV) network,which consist largely of coaxial cable.
COMMON TYPES OF COMMUNICATION DEVICECABLE MODEM
COMMON TYPES OF COMMUNICATION DEVICEMULTIPLEXER (MUX)– a device that combines two or more inputsignals from various devices into a singlestream of data and then transmits it over asingle transmission medium.
COMMON TYPES OF COMMUNICATION DEVICEMULTIPLEXER (MUX)
COMMON TYPES OF COMMUNICATION DEVICE• NETWORK INTERFACE CARD (NIC)– an expansion card that you insert into anexpansion slot of a personal computer orother device, such as a printer, enabling thedevice to connect to a network.
COMMON TYPES OF COMMUNICATION DEVICE• NETWORK INTERFACE CARD (NIC)
CONNECTING NETWORKSthousands of computer networks exist fromsmall networks to global networks, tointerconnect the many types of networksthere are many various types ofcommunications devices including these:
CONNECTING NETWORKSHUB– also called concentrator or multistationaccess unit (MAU), provides a central pointfor cables in a network, usually containports for eight to twelve computers andother devices.