Digital cellular service
In the late 1990s, carriers began migrating their customers from analog service to digital cellular service. Digital cellular allows carriers to increase privacy, reduce cloning fraud, and increase capacity by 3 to 10 times. Digital cellular signals are multiplexed and scrambled, making it more difficult for eavesdroppers to listen in to a conversation. Digital service also includes more features such as caller ID, call waiting, repeat dialing, and call return. A carrier that upgrades from analog to digital technology can offer better service to more customers.
PCS
In the early 1990s, the FCC auctioned off six more bands of the airwaves to be used for personal communications service (PCS). The auction was controversial and the stakes were high. Many people complained that the government had no right to collect money by “selling” the airwaves. The bids at the auction were much higher than predicted and the government was surprised at how much money it raised. The auction of the A, B, and C blocks netted the U.S. Treasury $17.9 billion. In the Washington/Baltimore market alone, AT&T Wireless paid $211,771,000 just for the right to broadcast phone calls. Some of the entrepreneurs who got the bids eventually defaulted on the payments. Consequently, PCS service was not rolled out as quickly as planned.
PCS service uses digital technology and is rich with features. PCS also uses less complex pricing and billing schemes than traditional cellular service. Because of these advantages, wireless carriers and customers alike are making the shift from analog wireless services to PCS.
Low Earth-Orbiting Satellites
Low earth-orbiting satellites (LEOS) provide wireless telephone service for users across the globe. The handheld phone transmits and receives signals to and from geosynchronous satellites. Once enough satellites are launched into space, a caller should be able to make and receive calls anywhere across the globe. This revolutionary technology will allow people everywhere to make voice calls, transmit data, or connect to the Internet from anywhere. The concept is especially attractive in isolated places such as the Andes Mountains, where the telecommunications infrastructure is significantly underdeveloped.
LEOS technology has many glitches, however. During the recent war in Kosovo, telephone lines were severely damaged. News correspondents brought in satellite phones to call the outside world. In spite of the hefty $2,000 to $3,000 price tag, these phones rarely worked properly, especially when used indoors.
Probably the biggest problem facing rapid LEOS deployment is the high cost of building the network. In 1998, the Iridium Company, daughter company of Motorola, first offered global wireless telephone service. Iridium spent more than $5 billion building its 66-satellite constellation that would provide coverage throughout the world. But in its first 2 years, the company enrolled only 10,000 customers. A small customer base means small revenue, and in 2000, Iriduim filed for bankruptcy. What began as a dynamic cutting-edge high-tech company quickly died as the result of financial problems. Even its major supporter, Motorola, refused to bail the company out. Iridium is now back in business, but it mainly targets commercial users in remote parts of the world, such as off-shore locations.
Showing posts with label Cellular service. Show all posts
Showing posts with label Cellular service. Show all posts
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.
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.
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.
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.
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