There Are Two Main Types of Cell Phone Networks (GSM

Multiple Choice

There are two main types of cell phone networks (GSM and CDMA) used in the world. CDMA is used primarily by Verizon and Sprint in the United States. GSM is used by AT&T and T-Mobile in the United States, as well as most of the rest of the world. In the United States, customers of AT&T and T-Mobile can receive calls from and make calls to customers of Verizon and Sprint. This indicates that

A) there is interconnection across the networks.
B) there is only one cell phone network.
C) regulation is the reason that consumers can call users of different networks.
D) the lack of interconnectedness raises costs for carrier services.