Radio communications

Communicating by radio is a method of sending or receiving sounds, pictures and data through the air by means of electrical waves.

We use the airwaves for many purposes: broadcasting most of our local and national radio and TV stations, in our mobile radio and telephone services, and to communicate on a global scale through distant satellites, which act as a kind of reflector in the sky, redirecting the information we send up to them.

Another important use of this means of communicating is in shipping. A ship that is in difficulty can call the nearest coast station, giving details of its situation and, if necessary, ask for help. We call this “ship-to-shore” radio. Radio can ensure greater safety in navigation (for example, to warn of bad weather or hazards in the shipping lanes) and it enables large amounts of information to be sent over land or water without support of several hundred kilometers of wires and cables. Radio networks can, therefore, be cheaper to install but often have fewer circuits than cable links. Radar systems also enable air-traffic controllers to follow and guide the flight paths from take-off to landing.

Radio-paging systems enable us to be contacted even though we do not have a telephone within easy reach. It is way of letting us know that something important has just happened and that we must act quickly. The system works through a pager or “bleeper”, a small receiver about a size of a packet of cigarettes, which you can keep in your pocket. When people want to contact you, they simply pick up the nearest telephone, dial your personal paging number free of charge, and wherever you are in the coverage area, your pager will bleep.(You must, however, be above, not below, ground level, for the signal will not get through if you are underground.) The bleeping informs you that someone is calling you. You can identify up to four callers on some types of equipment. The most modern type of radio-pager displays the number of the telephone the caller is ringing from. The main advantage of radio-paging is that you can be contacted wherever you are, even though you may be a long way from a telephone set.

Many companies which have personnel on business trips have found that radio-paging improves their competitive position and allows them to be more responsive to a lot of their customers` needs. It also increases company efficiency by cutting out many unnecessary and expensive journeys that are sometimes made by salesmen. This saves time and fuel costs. Doctors can be contacted immediately and return to their surgery or hospital, thus possibly saving the life of a very sick patient.

Task 8. Ответьте на вопросы по тексту.

1. How does the text define radio communications?
2. What examples does the text give of radio communications?

i) ship- to- shore radio ii)…etc.

1. Why can radio networks be cheaper to install?
2. What equipment does the radio- paging user need?
3. Where does the user keep this equipment?
4. Where must you not go if you wish to be contacted by radio- paging?
5. How can companies benefit from radio- paging? (Give three ways)
6. Why do many doctors carry a bleeper?