Mobile telephone communication to the automotive vehicle has been available to the general public since the 1960's. Service previous to cellular was the IMTS system which could be summarized as crowded even though there were only several thousand users per major market. This was due to the limited number of access channels per market, thereby limiting usage especially during the busy rush hours in the morning and evening.
Cellular equipment is an evolution of the older IMTS type equipment. Due to changes in technology, the equipment has come down an experience curve. Major reductions in parts count, size, and weight have reduced the telephone equipment from large boxes that needed to be mounted in the trunk to small, efficiently packaged sizes that have greatly improved mounting flexibility.
With the latest cellular equipment, it is possible to extend the office or home to the vehicle. The office of the future includes the automotive environment today with cellular communications.