The Network designates the technology and frequency ranges used to communicate via the phone. Communication networks may be designed for voice, text, data, fax and video. Currently GSM (Global System for Mobile Communications) and CDMA (Code Division Multiple Access) networks are the most common types of digital technologies, with Cingular and T-Mobile built on GSM, and Verizon Wireless and Sprint using CDMA. Nextel uses iDEN (Integrated Digital Enhanced Network). AMPS (Advanced Mobile Phone Service) technology is fast becoming obsolete.

The progression of network technology has advanced through the years. First generation (1G) mobile devices utilized analog technology, susceptable to interference. Second generation (2G) digital networks included GSM and CDMA. As an interim step building up to 3G, 2.5G involved overlaying higher-capacity data transmission capability to 2G digital wireless networks, allowing consumers to download data at faster speeds (such as EDGE for GSM networks or EV-DO for CDMA networks). Third generation (3G) networks supports much higher data rates, measured in Mbps, intended for applications other than voice (HSDPA, UMTS, and WCDMA).

1G Technology

AMPS (Advanced Mobile Phone Service) - An analog cellular radio standard that serves as the foundation for the U.S. cellular industry. AMPS represents the first generation of wireless networks.

2G Technology

CDMA (Code Division Multiple Access) - An air interface technology that was developed by the U.S. military and commercialized by the U.S. company Qualcomm. CDMA assigns a code to all speech bits, sends a scrambled transmission of the encoded speech over the air and reassembles the speech to its original form at the other end. CDMA supports SMS with a message length of 120 characters. With CDMA, each conversation is digitized and then tagged with a code. The mobile phone receives a signal to locate that particular code and it then deciphers the conversation off the airwaves. It codes each conversation expanding it 128 times, making it easy to decipher at the receiving end.

GSM (Global System for Mobile Communications) - GSM is a digital cellular phone technology based on TDMA that is the predominant system Europe, the Middle East, Africa, Asia and in parts of America and Canada. First introduced in 1991, the GSM standard has been deployed at three different frequency bands: 900 MHz, 1800 MHz and 1900 MHz. GSM 1900 is primarily deployed in North America. Named after its frequency band around 900 MHz, GSM-900 has provided the basis for several other networks using GSM technology. GSM uses narrowband TDMA which allows eight simultaneous calls on the same radio frequency. Along with CDMA and TDMA it represents the second generation of wireless networks.

iDEN (Integrated Digital Enhanced Network) - A wireless communications technology from Motorola that provides support for voice, data, short messages (SMS) and dispatch radio (two-way radio) in one phone. Operating in the 800MHz and 1.5GHz bands and based on TDMA, iDEN uses Motorola's VSELP (Vector Sum Excited Linear Predictors) vocoder for voice compression and QAM modulation to deliver 64 Kbps over a 25KHz channel. Each 25KHz channel can be divided six times to transmit any mix of voice, data, dispatch or text message. Used by various carriers around the globe, Nextel Communications provides nationwide coverage in the U.S.

3G Technology

UMTS (Universal Mobile Telecommunications System) - The goal of UMTS is to enable networks that offer true global roaming and can support a wide range of voice, data and multimedia services. A new-generation technology for rapidly moving data and multimedia over wireless devices. The European implementation of the 3G wireless phone system, UMTS provides service in the 2GHz band and offers global roaming and personalized features; designed as an evolutionary system for GSM network operators, multimedia data rates offered by UMTS are: vehicular - 144 kbit/s; pedestrian 384 kbit/s; in-building 2Mb/s.

WCDMA (Wideband CDMA) - A 3G mobile services platform, based on modern, layered network-protocol structure, similar to the protocol structure used in GSM networks. WCDMA has been designed for high-speed data services and more particularly, internet-based packet-data offering up to 2Mbps in stationary or office environments, and up to 384Kbps in wide area or mobile environments. The third generation radio standard that will offer voice, data, motion-video and other multimedia capabilities, and increases data transmission rates in GSM systems by using CDMA instead of TDMA. WCDMA has become the Direct Sequence (DS) mode in the ITU's 3G specification, which includes the 1X Multi-Carrier mode (1X MC) and 3X Multi-Carrier mode (3X MC). 1X MC (formerly known as cdma2000) and 3X MC comprise the 3G upgrade path for carriers already using CDMA (cdmaOne).