Karri Ranta-aho and Antti Toskala
This chapter presents a performance evaluation of HSPA Release 11 compared to the requirements for IMT-Advanced as defined by the ITU-R. First the IMT-Advanced requirements are presented and then the different features included in Release 11 3GPP specifications to address these requirements are briefly introduced to highlight how they help in achieving the improved performance. The achievable performance with different features is covered. This chapter is concluded by benchmarking with the LTE and LTE-Advanced.
The International Telegraphic Union Radiocommunications sector (ITU-R)  started the process for the new system, the International Mobile Telecommunications Advanced (IMT-Advanced), with a circular letter distributed in 2008. The circular letter was a call for radio technology proposals, in a similar fashion as had been done earlier for the IMT-2000 process in connection with the definition of 3G radio access solutions . Now the ITU-R was calling for proposals for radio technologies that could meet the requirements set for IMT-Advanced technology, widely termed the 4th generation (4G) mobile communication systems.
The ITU-R defined the requirements for the IMT-Advanced (4G) such that the system should be able to achieve the following :