The MS saves power during the Sleep intervals by powering down one or several components, depending upon the length of the sleep interval.Ī PSC definition includes parameters to control various aspects of the Sleep mode such as the length of Sleep and Listen windows, whether the Sleep window remains fixed or increases in a binary exponential manner in successive Sleep cycles before it reaches a predefined maximum value and whether traffic can be exchanged during the Listen window or not.
CAN THE SWITCH IN SLEEP MODE WINDOWS
To activate a PSC means to start Sleep/Listen windows associated with the class. A PSC may be repeatedly activated or deactivated. For each involved MS, the BS needs to keep context about its Sleep/Listen Windows and this is called a Power Saving Class (PSC). In Sleep mode, the MS alternates between periods of absence known as Sleep windows and periods of availability known as Listen windows. This allows the MS to quickly return back to active mode to send and receive traffic and avoid the additional expense of frequent connection termination/reestablishment. Thus, in Sleep mode the BS retains all the information related to the connections that currently belong to the MS as it does during Connected mode. Sleep mode also allows the MS to shut itself down for some prenegotiated interval of time, but unlike Idle mode, in Sleep mode the MS remains connected to the BS. Sleep mode conserves power when the MS is in Connected mode while still exchanging data. Rath Vannithamby, in Handbook of Green Information and Communication Systems, 2013 21.4.2 Sleep Mode in IEEE 802.16e