This permits the same channel you are talking on to be used for calls in other parts of the same metropolitan area without interference. Unlike local telephone service, which is provided by a monopoly, there is competition in cellular. Two classes of companies are allowed to offer cellular telephone service in every market. One cellular system can be owned by a telephone company, the other by someone else. Cellular Telephones come in two basic versions, as car phones and portable phones, with a briefcase hybrid.
Car phones are by far the most common, because they are much cheaper.
But most believe that, ultimately, portables will be the most popular. They will cost no more than five hundred dollars. They will emancipate people from the necessity of locating a phone to make calls. The bad news is, you will never be able to get away from the phone, and we'll call it progress. Car telephones include a small transmitter-receiver unit that is usually mounted in the trunk, an antenna and a control head that includes the handset.