EDGE Evolution, also called Evolved EDGE or EDGE II, is an upgraded version of technology that was ratified in Release 7 (Rel-7). It applies many of the techniques employed in HSPA+ to lower latency and increase the speed of EDGE. A key part of the evolution of EDGE is the utilization of more than one radio frequency carrier. This is designed to overcome the inherent limitation of the narrow channel bandwidth of GSM. Compared to existing versions of EDGE, EDGE Evolution is expected to provide:
- A dramatic increase in data rates. The actual amount depends on the version used, but peak download speeds and upload speeds are expected to increase 200 to 300 percent over EDGE.
- A 50 percent increase in spectral efficiency and capacity
- Reduced latency for initial access and round-trip time, enabling better quality of service (QoS) for Push-to-Talk (PTT) and Voice over IP (VoIP)
- Compatibility with existing frequency plans, thus facilitating rapid deployment in existing networks
- A simple upgrade to existing GSM equipment allowing a more efficient use of existing scarce radio spectrum
- A better seamless experience for subscribers as they roam from HSPA networks to Evolved EDGE networks
The methods standardized in Rel-7 to achieve these objectives include:
- Downlink dual-carrier reception to increase the number of timeslots that can be received without a need to receive and transmit on the same carrier from four on one carrier to 10 on two carriers for a 150 percent increase in throughput
- The addition of Quadrature Phase Shift Keying, 16 QAM and 32 QAM as well as an increased symbol rate (1.2x) in the uplink and a new set of modulation/coding schemes that will increase maximum throughput per timeslot by 38 percent
- A reduction in overall latency by lowering the TTI to 10 milliseconds and by including the acknowledgement information in the data packet
- Downlink diversity reception of the same radio channel to increase the robustness in interference and to improve the receiver sensitivity
Following the Rel-7 industry standardization, Ericsson and Nokia Siemens Networks are among those companies committed to launch EDGE evolution as a software upgrade of existing infrastructure in 2009. RIM has also endorsed EDGE evolution.
No comments:
Post a Comment