In order to satisfy the spectrum requirements of the future international mobile telecommunication (IMT) systems, to realize scientific allocation and usage of spectrum resources and to avoid spectrum waste brought by allocation in advanced, there is a need to make a reasonable estimation for the spectrum demands of future IMT systems. The estimation results can also provide guidelines for the subsequent spectrum planning and assignment work. This paper gives a description of study progress of related spectrum estimation for future IMT systems. From the analysis of current work and practical situation, the key factors in the estimation methodology are summarized to provide a reference for the following work.
 Qualcomm Inc. “Document 5D/266-E, Information Related to the Level of Asymmetry between the Downlink and Uplink for Traffic in Response to Liaison from ITU-R JTG 4-5-6-7 on Spectrum Requirements,” 2013.