Why do I not get 11Mbps from my WiFi network?

The 802.11b standard specifies an 11Mbps network. You'll notice however, that you won't get close to that. Especially on your Axim. Want to know why?

1. The throughput that we see on PPCs tend to be lower than 1.5Mbps.
2. 11Mbps refers to the available bandwidth in the air. However if more than one device is transmitting at once. their signals get scrambled together. For this reason they each run a protocol (called CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)) to ensure that collisions are minimised. But there is significant overhead.
3. Most network traffic is bi-directional. So even when simply downloading a file from the Internet there is a steady stream of traffic from the Server to the PC/PDA and then there is a steady stream of acknowledgements from the PC/PDA back to the server. so traffic is moving in both directions, both nodes transmitting and as mentioned in Point 2, they have to take care not to conflict with each other. So as more nodes are added, there is more potential for collisions. More collisions means more overhead.
4. Slow memory, low bus speeds, and narrow data paths also contribute to the lower speeds.