Enhanced Data Rates for GSM Evolution (EDGE) is a third-generation (3G) technology that enables high-speed packet-data services such as Internet access and streaming multimedia. EDGE supports peak theoretical network data rates of 474 kbps, with average throughput of 70 to 130 kbps on both the downlink and the uplink. The average rates are fast enough to support a wide range of data services, including streaming audio and video, fast Internet access and large file downloads. EDGE also can support Push-to-Talk (PTT) services.
The International Telecommunication Union (ITU), which sets telecom standards for worldwide use, approved EDGE as a 3G standard in July 2000. In July 2003, the world’s first commercial EDGE network launched. By 2010 there were more than 500 commercial EDGE networks operating in 200 countries worldwide. Reasons for this worldwide expansion include:
Most HSPA operators also offer EDGE, particularly in rural areas as EDGE is a cost-effective way to provide broadband data services in areas that have not yet been upgraded to HSPA or that are too sparsely populated to justify HSPA. As a result, when HSPA customers travel to areas with EDGE, they still have the benefit of mobile data access.
Due to the minimal incremental cost of including EDGE capability in GSM network deployment, virtually all new GSM infrastructure deployments are also EDGE-capable and nearly all new mid- to high-level GSM devices also include EDGE radio technology. Therefore, EDGE is always available as a fallback on HSPA devices. As a member of the GSM family of technologies, EDGE offers international roaming. EDGE is backward compatible with GSM and GPRS, so when a user travels to an area where EDGE is not yet available or is not supported by roaming agreements, he or she still can access many voice and data services. As a result, users enjoy the convenience of being reachable with their EDGE device when traveling throughout the world, as well as the ability to access messaging and other mobile data services that they use in their home market.
Like GPRS, EDGE provides an always-on data connection, so users do not have to log on each time they want data access. The packet architecture also means that users only pay for the data itself rather than for the airtime used to establish a connection and download data.
Although EDGE is a data technology, it also helps boost the number of voice calls that a network can handle simultaneously by sending data up to 150 percent more efficiently than GPRS. With EDGE transmitting more data into the same amount of bandwidth, the voice-coding, or vocoder, technology in the GSM voice network can be upgraded to a version that increases voice capacity by 15 to 20 percent.
It is important to note that EDGE technology is continuously improving. For example, Release 4 significantly reduced EDGE latency (network round trip time) — from the typical 500 to 600 milliseconds (ms) to about 300 ms. Operators also continue to make improvements in how EDGE functions, including network optimizations that boost capacity and reduce latency. The impact for users is that EDGE networks today are more robust, with applications functioning more responsively. Evolved EDGE in Release 7 and also in Release 8 introduces significant new features.