In mid-2009, most broadband cell phones operated on third generation (3G) mobile technology networks. These networks include the Global System for Mobile communications (GSM) and Code Division Multiple Access (CDMA). A newer technology, Long Term Evolution (LTE), may enhance and eventually replace these older networks. LTE access promises faster speeds for mobile wireless users and lower costs and enhanced capacity for network providers.
CDMA is prevalent in the United States; however, over 80% of the world's mobile phones run on GSM networks as of 22 September 2008. Both CDMA and GSM continue to grow. Verizon Wireless® and Sprint® use CDMA, while AT&T®, a distributor of the Apple® iPhone™ in the United States, leverages the GSM standard.
LTE is under development to enable wireless providers using both types of networks to transition from 3G technology to fourth generation (4G) networks and equipment. For consumers, LTE will enable existing applications to run faster, plus make available new mobile phone applications. Enhanced video and presentation mobile phone applications may be included.
LTE uses radio waves to allow more data to be transferred over the same bandwidth used by 3G equipment. As a result, service providers should be able to get more data transfer out of their existing cells and possibly lower the cost to run their networks. Since LTE connects to existing networks, providers can plan for a seamless transition, then continue to use legacy CDMA and GSM networks as backups.
The way LTE achieves its speed could lead to a disadvantage: the start-up costs of service providers and consumers for equipment upgrades. LTE has adopted multiple-input multiple-output (MIMO) technology. As a result, cell basestations may need additional transmit and receive antennae. Mobile phones may have one transmit antenna and up to two receive antennae. Service providers may have to upgrade basestations, and consumers will need to buy new phones to utilize these upgraded networks.
The industry group that provides LTE network standards is the 3rd Generation Partnership Project (3GPP). LTE was first developed for data transfer. Mobile providers and equipment manufacturer industry leaders joined together in early 2009 to create the Voice over LTE via Generic Access (VoLGA) Forum. VoLGA is devoted to expanding LTE access technology so it can also support voice and Short Message Service (SMS) text messaging using existing networks. The goal of this forum is to allow wireless broadband providers to transition to this new technology without rebuilding their entire networks from the ground up.
