Wireless Oom

The device periodically wakes up and check if there is page for me or not.
The below diagram shows when the device wakes up to check its page. (Only at a particular PI location, otherwise in sleeping.)
related posts: here here
here here

PI (Paging indication)
is
a short indicator that is transmitted on the PICH to tell the UE that there is a paging message on an associated paging channel carried by the SCCPCH.
The number of PIs per radio frame (Np) can be 18, 36, 72 or 144.
Once the UE knows paging occasion (SFN), then the UE needs to [...]