Buffering Protocol

We discussed in Section 5.2.4 that buffering over infrastructure networks can be achieved by using the IEEE 802.11 PSM. We successfully implemented this scheme over Native WiFi cards described in Section 3.2. For non-Native WiFi (legacy) cards, we were constrained by the proprietary software on them that do not expose any API in Windows to programmatically set the resolution of power save mode. Therefore, we were unable to implement the buffering algorithm for these WLAN cards as described previously. We get around this problem by buffering packets at the end points of the infrastructure networks, using a similar scheme described for ad hoc networks in Section 5.2.2. The MultiNet Service keeps track of the end points of all on-going sessions, and buffers packets if the destination is currently in another network. For wide scale deployment, it is unreasonable to expect Internet servers, such as Yahoo or Amazon, to do the buffering for MultiNet nodes, but it is practical to implement the buffering algorithm at the APs as described in Section 5.2.4. Fortunately, with Native WiFi based cards and APs, all buffering is possible in the AP's operating system, and implementing our scheme is not a problem.