paulplatt

In the last post, I promised to discuss femtocells, picocells, etc. but that will need to wait a few days. To understand why different cell types are needed we must first discuss how cell phones are used. The bandwidth crisis is huge and multifaceted. Its roots stem from the changing nature of cell phone use. We must first look at and understand how cell phone use has changed and the emerging demands of the mobile market.

Along with the widespread adoption of the automobile, came the desire to have a telephone in the car. The first systems, circa 1946, were simply radios that connected to telephone offices and could be patched into the phone system by an operator. In the early 1960’s automatic dialing arrived. The TV series Burke’s Law, from the same era, had Amos Burke, played by Gene Barry, being chauffeured around in his Rolls-Royce Silver Cloud II which prominently featured a phone in the back seat. Everyone understood the message. Just like a Rolls Royce, radio phones were only for the very rich.

The problem with the early car phone systems was cost and capacity. The two were tightly related. Because the car phone was closely related to a standard radio set, only a few people could use the system at a time. A small user base meant high cost. Each car phone transmitted over a large distance. Today, CB radio is similar. With CB radio there is a limited number of channels and if one person is on a channel then that channel is tied up for a considerable distance.

In 1947  Douglas Ring and Rae Young of Bell Labs proposed hexagonal cells for car phones. However the technology didn’t exist and the system, as proposed, lacked a lot of necessary features. In 1970 Amos Joel, Jr., also of Bell labs,  invented an automatic call handoff system to transfer calls from cell to cell. In 1982 the FCC approved the Advanced Mobile Phone System and the cell phone as we know it today was being born. The concept dog cells together with calls being passed form cell to cell allowed many users on a given channel as long as they each used a different cell. This is a key concept. The idea is to generate additional cells as usage increases. With more and more usage comes the need for many more and much smaller cells.

The cell phone rapidly took off. Initially systems were bulky and often installed permanently in automobiles. This generalized the location specific nature people associated with telephones. Cell phones were associated with automobiles. A certain phone number might be for Bill’s car while another number was Bill’s house and a third his office. Phones had physical locations even if some of those locations were automobiles and able to move about.  The cell phone system itself only handled phones in cars.

Today the old concept of a cell phone being a car phone is all but gone. We use our cell phones in cars but we do so much more with them. The home phone is rapidly being replaced. This is an interesting generational change to observe. Older people generally hang on to the concept of a home phone and the associated home number. Younger people often dispensed with that old concept. For them, the phone number is tied not to a physical location or an object but to a person. In a few cases people have taken an intermediate step. There is still a home phone number, but it calls a cell phone rather than an old style phone line. Cordless phone systems, such as the Panasonic KX-TG6582T, allow linking a cell phone throughout the house in case you don’t want to carry your phone around. Even this is beginning to be passed by. Modern smartphones have become so multifaceted and embedded in our lives that we require their presence at all times. At work we hang on to the old office phone but more and more of our calls are over our cell phones. Why guess if a person is at his desk? Just call his cell.

The result of the move from car phone to personal phone has transformed how the bandwidth problem must be viewed. No longer is it adequate to think of adding capacity along major roadways. Cellular performance inside businesses is now important. Neighborhoods which used to have low call density except, perhaps, during rush hour now have high call density since home calls are being made over the cellular network. Solving the bandwidth issue will require attacking car, home and business. Furthermore, this will require more of a partnership arrangement between businesses, individuals and the cell companies.

The hardest problem to solve is the stadium problem. Imagine a stadium filled with 100,000 people all wanting to use their phones. Worse, imagine they all want to stream video to smartphones. Yikes! Solving the stadium problem is the most technically challenging hurdle the providers face. This particular problem will get a post all its own later in this series. For now the more tractable issues of home, car, and business are up for discussion.