1. Identify three benefits associated with the use of telecommunications technology.
2. What are the elements in a telecommunication system?
3. Compare and contrast the wireless communication channels.
4. Identify three telecommunications media that physically connect to telecommunication devices.
5. Define and describe three different services offered by telecommunication companies?
- Cost, time and distance?
- From a general model of telecommunications, there are 5 elements involved in moving the signal. The communication starts at the origin, a sending person (and computer), then goes through some telecommunications device, say a modem for example. Next the signal is transmitted through a medium, such as copper phone wires, to another telecommunications device, and finally a receiving computer – and hopefully a person too.
- Microwave, satellite, radio, cellular radio, and infrared:
Microwave towers transmit signal up to 30 miles – the curvature of Earth interrupts the line of sight at larger distances. Long distance telephone is a typical usage scenario for microwave as it is suited to high volume communications.
Satellite is replacing microwave as it reduces the 30 mile distance problem. Still using line of sight, but the footprint of a high altitude satellite is huge, overcoming the need for relay stations.
Radio-wave frequencies transmit over short distances and do not require relaying. Easy to install and inexpensive devices send radio waves through normal office walls, but can create electrical interference problems with other office equipment.
Cellular radio sounds like a localised low power relay antenna system for mobile telephone users and data communications. Computer processing coordinates the transmissions as mobile users move from one area to another.
Infrared light, not visible to the human eye, can be modulated or pulsed for conveying information. Your TV remote control uses IR and possibly peripherals communicating with your computer also utilise it.
- Coaxial cable, twisted-pair wire, and fiber-optic cable are three media which physically connect telecommunication devices.
- Services offered by telecommunications companies include:
- Switched lines are telephone lines provided by common carriers that people can access from their computers to transmit data to another computer. The transmission is routed or switched through paths to its destination.
- Integrated Services Digital Network [ISDN] is a high speed data transmission technology transferring voice, video, image and data simultaneously. ISDN uses existing telephone lines, and forms a popular upgrade for firms whose requirements exceed standard telephone capacity.
- Digital Subscriber Line [DSL] provides high speed digital data transmission from homes and businesses over existing telephone lines. A popular alternative to ISDN, and modems are necessary with DSL technology.