Implementation

We have implemented MultiNet on Windows XP and tested it on small scale IEEE 802.11 networks. Windows provides a Network Driver Interface Specification (NDIS) as an intermediate layer between the network device drivers and IP. We implemented MultiNet as a combination of an NDIS intermediate driver and a service (daemon). The service has the buffering and switching logic; it passes instructions to the driver, which implements the mechanics for this buffering and switching. We require all the wireless nodes to implement MultiNet. However, no changes are required in the wired nodes for MultiNet to work. The APs too do not require any modification if the IEEE 802.11 PSM is used, as described in Section 5.2.4. We note that MultiNet still works if other wireless nodes do not run MultiNet, or the APs do not buffer packets. However, the performance degrades significantly in these cases. In the rest of this section we describe the details of our implementation.