Super 3G (LTE)

In response to the rapid increase in multimedia and ubiquitous traffic, DOCOMO is developing technologies for Long Term Evolution (LTE), or Super 3G, an advanced version of 3G that will serve as the stepping stone to 4G (IMT-Advanced). Using current and planned new 3G spectrum bands, Super 3G (LTE) will enable high-speed transmissions of up to 300 Mbps (megabits per second) in downlink, a major advance in the evolution of mobile systems. It will also cut down significantly on control and transmission delays, thereby helping to ensure the long-term competitiveness of the system.

One of the main characteristics of Super3G (LTE) is its dramatically improved data transmission rates, the goal being downlink at up to 300 Mbps and uplink at up to 75 Mbps, as agreed upon by the 3G Partnership Project (3GPP). A related characteristic is reduced delays thanks to shorter frame and simple protocol in the evolved air-interface and network architecture. In fact, latency is expected to be less than 100 msec for call setup and to be less than 5 msec in radio access network (RAN) during data transfer. Another key characteristic is significant improvement on spectrum efficiency. The ambitious targets for user throughput and spectrum efficiency are between two and four times those of HSPA.

Although Super3G (LTE) will use the existing 3G spectrum, advanced new technologies incorporated in its radio access system will enable for significantly improved performance. One such technology is orthogonal frequency division multiplexing (OFDM), which transmits high-speed data using numerous multiple sub-carriers in parallel, a method especially suited to areas with multipath propagation, such as urban environments. Another key technology is multiple-input multiple-output (MIMO), which uses multiple transmission and reception antennas on the same frequency to create different data streams that are multiplexed spatially. Radio access networks will use simple architecture for low latency and low-cost network construction. The core networks of Super3G (LTE) radio access will be all-IP networks, which eventually could be configured to smoothly accommodate more advanced 4G (IMT-Advanced) radio access systems someday.

The 3GPP is devising standardized specifications for Super3G (LTE), with DOCOMO's aggressive activities playing a key role in the process. In conjunction with significant advances in the standardization of the LTE RAN, DOCOMO began developing experimental equipment in July 2006. Following the construction of a prototype Super3G (LTE) experimental equipment, indoor and field trials began in July 2007 and February 2008, respectively, and resulted in the achievement of up to 250 Mbps in downlink. Future tests will evaluate transmissions in typical operating environments. Development of commercial equipment, which will be carried out in parallel with the evaluation of the prototype equipment, is targeted for completion by the end of 2009.

For more infomation, please visit Super 3G Technology Trends.
Part 1: Super 3G Overview and Standardization Activities
Part 2: Research on Super 3G Technology

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Posted on June 13, 2008