Switching on IEEE 802.11 Network Cards

Implementing the above strategies using IEEE 802.11 PSM requires some modifications. In PSM the node sleeps for some number of AP Beacon Periods, called the Listen Interval. Consequently, the granularity of the Activity Periods on each infrastructure network is the AP Beacon Period. The Listen Interval is rounded to the multiple of the Beacon Period that is closest to the Switching Cycle. We also allow MultiNet nodes to sleep to save power. The nodes follow a protocol similar to the IEEE 802.11 PSM. If it does not have any packets to send on a particular network, it goes to sleep for the rest of its Activity Period. It then wakes up after the Activity Period to be active on the next network.