Cellular service

Cellular service
Cellular telephone service has more capacity than the previous mobile telephone service because it divides an area into hexagonal shaped cells. Each cell uses different frequencies from the adjacent cells. The limited number of frequencies could be recycled in other cells, which allowed more simultaneous calls. Cellular telephone service is an analog technology. Figure 1 illustrates the different cells in an area.


Figure 1: Cell map.

In the early 1980s, the FCC divided the country into 734 distinct cellular service markets. In each market, the FCC divided the available airwaves into an A-block and a B-block. Two cellular service providers would operate in each market. The A-side carrier was usually an independent company such as Cellular One, while the B-side carrier was operated by the local telephone company, such as BellSouth Mobility. Even today, there are only two providers of cellular service in each market. But in most markets, both the A-side and B-side carriers allow other companies to resell their service, which results in more vendor choices for the customer. In the Midwest, Ameritech Cellular resold GTE’s service until it built its own digital network. Most consumers are unaware that cellular companies may share the same network with their competitors.

For example, a construction supervisor who worked in a low valley was disappointed with his carrier, GTE. His work area was obscured by hills that prevented the cell phone from receiving the signal from the radio tower. He was, in effect, in a “dead zone,” which is an area that cannot receive the signal from the tower due to an obstruction, such as a hill (see Figure 2). The construction supervisor switched to Ameritech Cellular but was disappointed because his phone still did not work in the valley. He switched companies, purchased a new phone, and changed phone numbers, but his coverage was exactly the same because the new carrier used the same network as the old carrier.


Figure 2: Dead zone.

When traditional analog cellular service became popular, cellular providers needed to increase the capacity of their networks. Initially, they just divided the cells into smaller cells, which allowed them to carry more calls but also resulted in more dropped calls, especially near cell boundaries. Cellular customers can be fickle and will quickly change carriers if they have trouble making calls.

Customers were also disappointed with the insecurity of cellular networks. Using analog scanners, eavesdroppers can easily listen to a cellular phone conversation. The most famous case involving this was when an elderly couple listened in to Congressman Newt Gingrich’s cellular calls.

Even more disappointing for the cellular customer is the practice of cloning, when perpetrators clone a cellular telephone by learning its electronic serial number (ESN). This ESN is then reprogrammed into another handset, and the perpetrator makes unlimited calls on this phone. No one will find out until the charges for these calls show up on the innocent customer’s bill. The lack of security with analog cellular service drove many customers to switch to digital cellular service.