With the global burgeoning of 3G development, LTE, shouldering the responsibility of technological transition from 3G to 4G, is also facing its critical moment which may usher a fresh round of spiraling development. As the current situation, future commercialization and evolution to 4G have all been widely focused, during the LTE seminar, representatives of the Forum members focused simultaneously on the new achievement on LTE-advanced technology.

Coordination between LTE-Advanced and IMT-Advanced

In March 2008, ITU-R officially started the IMT-Advanced standardization process by soliciting proposals from its fellow members. During the ITU-R WP5D conference held in Dubai in July, ITU defined the minimum requirement of IMT-Advanced which includes 8 indicators like cell spectral efficiency, peak spectral efficiency and spectral bandwidth etc. These 8 indicators are to be used as key standard to assess if a proposal is IMT-Advanced qualified.

As a leading 3G telecommunication standardization body, 3GPP will submit its 4G-oriented LTE-Advanced proposal independently. Since the beginning of March 2008, 3GPP has already started its research work on IMT-Advanced technology and set up a detailed timetable in line with the time frame of ITU. There are two important time point in ITU-R WP5D timetable: First the ending of the 6th WP5D conference in Oct 2009 is the deadline for proposal submission. Second, technical framework and core technical feature of IMT-Advanced will be clarified in 9th WP5D conference to be held in October 2010. 3GPP strictly scheduled its work around these two crucial time points, planning to: submit LTE-Advance preliminary, complete and final version of proposal to ITU-R WP5D in Sep. 2008, May 2009 and Sep 2009 respectively.

Requirement on LTE-Advanced higher than IMT-Advanced

LTE, commonly referred to as 3.9G, is proved quite similar to 4G technical target. LTE has met the fundamental IMT-Advanced requirements, except for the max bandwidth and the uplink peak rate.

The overall design of evolving LTE into LTE-Advanced technology has much exceeded the minimum LTE requirements. In June of 2008, 3GPP completed the LTE-A technical requirement report, proposing the minimum LTE-A requirements that the downlink peak rate reaches 1Gbps while the uplink peak rate reaching 500Mbps with the uplink and downlink spectrum utilization respectively reaching 15Mbps/Hz and 30Mbps/Hz. All the above index have surpassed the minimum technical indexes proposed by ITU, possessing obvious superiorities.

From the technical requirement prospect, LTE-Advanced up/downlink peak speed are 6.6 and 3.3 times as those of LTE respectively. The up/downlink spectral efficiencies are also 4 and 2 times as those of LTE. These achievements greatly enhanced the performance of LTE and completed the transition from 3.9G to 4G. Aiming at those targets, 3GPP subsequently has mapped out several research directions: In order to realize higher transmission rate and to av