Without Power Save Mode

We analyze the two schemes of connecting to multiple networks with respect to the performance on the network and the amount of power consumed. In our simulated scenario, each of the radios gives the best achievable throughput on both the networks. As shown in Table 2, the average throughput of MultiNet in the infrastructure mode is 4.35 Mbps compared to 5.8 Mbps in the two radio case. The average throughput in the ad hoc network is 1.1 Mbps in MultiNet and 4.4 Mbps when using two radios. Switching results in lesser throughput across individual networks, since it is on a network for a smaller time period. Consequently, the scheme of using multiple cards gives much better throughput as compared to MultiNet when connected to multiple networks.

Figure 7: Packet trace for the presentation and chat workloads over the ad hoc network

Table 2: The average throughput in the ad hoc and infrastructure networks using both strategies of MultiNet and two radios

Network	Two Radio	MultiNet
Ad Hoc	4.4 Mbps	1.1 Mbps
Infrastructure	5.8 Mbps	4.35 Mbps

However, the scheme of using multiple radios consumes more power. Each radio is always on, and therefore keeps transmitting and receiving over all the networks. Even when it is not, the radio is in idle mode, and drains a significant amount of power. Figure 8 shows the amount of energy consumed by the MultiNet scheme and the two radio scheme for the above application. Two radios consume around double the power consumed by the single MultiNet radio.

Figure 8: Comparison of total energy usage when using MultiNet versus two radios