System-Level Simulations with the IMT-Advanced Channel Model
One of the main applications of channel models is to enable the performance evaluation of wireless systems by means of computer simulations. Simulations of wireless systems like LTE-Advanced are essential in the research and standardization phase when the technology is still being developed. At this stage, prototypes are often not available and testing different candidate features in the field would be too expensive and time consuming. In comparison, simulations can be set up easily and deliver quick results. For the simulation results to be reliable, however, both the channel as well as the investigated wireless system have to be modeled accurately enough. The accuracy of the channel model is important because the performance gains over legacy systems delivered by LTE-Advanced systems mainly stem from a better exploitation of the radio channel's selectivity in the time, frequency, and spatial domain. Consequently, the International Telecommunication Union (ITU) adopted a well-established spatial channel model developed within the WINNER project when it defined detailed guidelines  for the evaluation of LTE-Advanced and IEEE 802.16m-2011 WirelessMAN-Advanced as so-called International Mobile Telecommunication (IMT)-Advanced compliant technologies.
In Sections 13.2 and 13.3 of this chapter, we will present the ITU's evaluation guidelines ...