The Upgrade of the CMS Tracker for Super-LHC

The CMS experiment at LHC is planning a major upgrade of its tracking system to adapt to an expected increase in luminosity of the accelerator by an order of magnitude to $10^{35}$\,cm$^{-2}$s$^{-1}$, expected to be reached about ten years after start-up. The CMS tracker will have to cope with several hundred interactions per bunch crossing and fluxes of thousands of charged particles emerging from the 40\,MHz collisions. This will require major developments of detector technology and R\&D has begun to address the expected challenges. Among the most important are the radiation tolerance of sensors and other components, the provision and distribution of power for both electronics and sensors, the removal of increased heat loads, and the development of low power, but highly performing electronics in more advanced technologies. CMS has also identified a novel requirement, which is to provide tracker data to contribute to the first level trigger, which must maintain the 100\,kHz rate for compatibility with existing sub-detector systems while increasing the trigger decision latency by only a factor of two. The motivations for the upgrade, recent progress in several aspects of the R\&D as well as the current status of designs of a new tracker is described.