TELECOMMUNICATIONS Communicating information Via electronic means over some distance Service provided by telecom companies telephone, mobile phone, wireless transmission data communication. Cable TV, satellite,…
HUANG Lihua, Fudan University TELECOMMUNICATIONS • Communicating information VIA electronic means over some distance • Service provided by telecom companies: telephone, mobile phone, wireless transmission, data communication, Cable TV, satellite, ………….. *
Telecommunication Concept Telecommunication is the electronic collection, exchange, and processing of data or information, including text, picture, voice, and other information that is digitally coded and intelligible to a variety of electronic machines omputer Computer Communicatio Communication Processor Processor Network Software
HUANG Lihua, Fudan University Telecommunication Concept • Telecommunication is the electronic collection, exchange, and processing of data or information, including text, picture, voice, and other information that is digitally coded and intelligible to a variety of electronic machines. Computer Communication Processor Communication Processor Computer Network Software
The Spectrum of Telecommunications-based Service Available POTS-plain old · Broadcast tv telephone service Communications Entertainment. High-definition TV Cellular/PCS systems Enhanced Pay-per-view Mobile radio Video-on-demand Video telephony Interactive TV Videoconferencing Interactive video games Telecommuting Video catalog shopping Internet access Distance learning Image networking Desktop multimedia Transaction service Information transactions
HUANG Lihua, Fudan University The Spectrum of Telecommunications-based Service Available • Broadcast TV • High-definition TV • Enhanced Pay-per-view • Video-on-demand • Interactive TV • Interactive video games • Video catalog shopping • Distance learning • Desktop multimedia • POTS-plain old telephone service • Cellular/PCS systems • Mobile radio • Video telephony • Videoconferencing • Telecommuting • Internet access • Image networking • Transaction service Communications Information transactions Entertainment
Electronic Signals Telecommunication media can carry two basic type of signals, ANALOG(模拟) and dIgital 数字) Analog signals are continuous waves that" carry information by altering the characteristics ( amplitude振幅 and frequency频率) of the wave Digital signals are discrete on-off pulses that convey information in terms of ls and Os, just like the cpu in computer 00101101911010010101011011000109000b11010010010 nalog data transmission Digital data transmission wave signal pulse signal)
HUANG Lihua, Fudan University Electronic Signals • Telecommunication media can carry two basic type of signals, ANALOG(模拟) and DIGITAL （数字）. • Analog signals are continuous waves that “carry” information by altering the characteristics ( amplitude振幅 and frequency频率) of the wave. • Digital signals are discrete on-off pulses that convey information in terms of 1s and 0s, just like the CPU in computer. 0 1 0 0 1 0 1 0 Analog data transmission (wave signal) Digital data transmission (pulse signal) 0010111010011101001010101110111100100010000101111010110100111010010010110010101101100
O Telecommunication System Computers Terminals(Input /Output Devices) Communications Channels(media) · Processors( Modems调制解调器; multiplexers(多 路转接器; Internetwork Processors) Host Network software Host Compute Computer Telecommunication media (channelS) PC or Multiplex Modem Front End Termina Modem k- Multiplex Processor Front end Receiver Processor
HUANG Lihua, Fudan University Telecommunication System • Computers • Terminals (Input / Output Devices) • Communications Channels (media) • Processors (Modems调制解调器; multiplexers(多 路转接器;Internetwork Processors) • Network software Host Computer PC or Terminal Multiplex Modem Modem Multiplex Front End Processor Host Computer Front End Processor Receiver Telecommunication media (channels)