Providers use each others’ towers in many areas, creating a complex web that offers the widest possible network coverage to subscribers.
Frequencies
Many network subscribers use mobile networks’ frequencies at the same time. Cell tower sites and mobile devices manipulate the frequencies so that they can use low-power transmitters to supply their services with the least possible interference.
3G, 4G, and 5G Networks
Mobile networks have evolved through a series of generations, each representing significant technological improvements over the previous generations. The first two generations of mobile networks first introduced analog voice (1G) and then digital voice (2G). 1G GPRS and 2G EDGE on GSM networks as well as 2G CDMA networks allowed for data connections although they were very slow. Subsequent generations supported the proliferation of smartphones by introducing data connections (3G) and allowing access to the internet. 4G service networks improved data connections, making them faster and better able to provide greater bandwidth for uses such as streaming. The latest technology is the 5G network, which promises even faster speeds and greater bandwidth compared with 4G while reducing interference with other nearby wireless devices. Where 4G uses frequencies below 6 GHz, newer 5G networks use shorter wavelength signals with much higher frequencies, in the range of 30 GHz to 300 GHz. These frequencies provide higher bandwidth and allow signals to be more directional, thus reducing interference.
Leading Mobile Network Providers
Cellular service providers in the U.S. range in size from small, regional companies to large, well-known corporations in the telecommunications field, such as Verizon Wireless, AT&T, T-Mobile, US Cellular, and Sprint.
Types of Mobile Networks
The mobile technologies that large mobile service providers use varies, and mobile devices are built to use the technology of the intended carrier and region. The two main mobile technologies in use are Global System for Mobile communications, which is an international standard, and Code Division Multiple Access, owned by Qualcomm. GSM phones don’t work on CDMA networks, and vice versa. Long-Term Evolution is based on GSM and offers greater network capacity and speed.
GSM vs. CDMA Mobile Networks
Signal reception, call quality, and speed all depend on many factors. The user’s location, service provider, and equipment all play a role. GSM and CDMA don’t differ much on quality, but the way they work does. From a consumer standpoint, GSM is more convenient because a GSM phone carries all the customer’s data on a removable SIM card; to change phones, the customer simply swaps the SIM card into the new GSM phone, and it connects to the provider’s GSM network. A GSM network must accept any GSM-compliant phone, leaving consumers quite a bit of freedom over their choices in equipment. CDMA phones, on the other hand, aren’t as easily transferred between carriers. CDMA carriers identify subscribers based on safelists, not SIM cards, and only approved phones are allowed on their networks. Some CDMA phones use SIM cards, but these are for the purpose of connecting to LTE networks or for flexibility when the phone is used outside of the U.S.
