Topology Creation On the ORBIT Testbed

As an initial approach towards full scale arbitrary topology mapping onto the ORBIT testbed using a combination of transmit power control, noise injection as well as adjusting the carrier sensing thresholds, we plan to start with a few simple topologies that reflect a few realistic wireless scenarios commonly observed

Note that all the above topologies will be using the 802.11a radios and the associated PHY rates. Users may use the steps as guidelines for 802.11b/g benchmarking results if required in their experiment.

• Topology1: Simple point to point link with configurable PER
• Topology2: Simple Hotspot AP scenario with a distribution of clients (at different PHY rates)
• Topology3: Near-far communication pairs (Capture effect)

Topology 2: Simple Hotspot AP scenario with a distribution of clients (at different PHY rates)

This represents the simplest basic topology comprising a point to point link (either infrastructure AP to client or peer to peer) with a configurable packet error rate for certain packet sizes

Topology 2: Simple Hotspot AP scenario with a distribution of clients (at different PHY rates)

This represents a typical hotspot AP scenario with a distribution of users (both near the AP, on the edge of the AP coverage and some in the middle. Users will experience links with different sustainable PHY rates in this scenario.

An example script with 1 hotspot AP and 10 clients with different PHY rates to the AP is attached below.

Topology 3: Near-far communication pairs (Capture effect)

This represents an interesting real life phenomenon observed in hardware devices which is the capture effect.