The pixel detector of the Compact Muon Solenoid (CMS) experiment at the CERN LHC [1] is a hybrid silicon pixel tracking detector and is crucial for the reconstruction of particle trajectories as well as for the identification of secondary decay vertices [2, 3]. The current CMS pixel detector has been designed to withstand an instantaneous luminosity of L= 1× 1034 cm− 2s− 1 and performs well under these operating conditions [4]. However, based on the excellent performance of the LHC, it is anticipated that peak luminosities of twice the original design value are likely to be achieved before 2018 and then probably significantly exceeded during the so-called Phase I period, which runs from 2018 until 2022. At higher luminosity and increased hit occupancies the present pixel detector would be subject to severe inefficiencies arising from dead time, limited buffering capabilities, and the limited …