that the bss will move to another channel shortly in another example the beacon frame may indicate that the access point changes the enhanced distributed channel access edca parameters however if a station in standby mode has to wake up to receive each beacon frame to receive potential changes in the beacon frame having a separate tim frame derives no benefit the power savings derives from the station only receiving the much shorter tim frame to address this potential difficulty the tim frame can also include a check beacon field fig1 illustrates a tim control frame which includes check beacon field 1608 which is a one octet fixed field all remaining fields and elements are similar to their corresponding counterparts in fig8 check beacon field 1608 is indicative of whether a change in the beacon frame has occurred that is significant and warrants a station to read the following beacon frame such as examples given above insignificant changes such as changes to the timestamp are not indicated by this field check beacon field 1608 could simply be a boolean state which indicates whether the following beacon frame has changed significantly relative to the past beacon frame however if a station somehow missed the tim frame indicating the change in the beacon it may never become aware that a.