1. Understanding Radio Irregularity in Wireless Networks
Joint work with Patrick Stüdi, Fabian Kuhn and Gustavo Alonso

2. Content
Network Model
Connectivity
Edge Length
Interference

3. Network Model
Connectivity
Edge Length
Interference
Network Model (1)
Wireless network: network of computers (nodes) without a fixed infrastructure, nodes communicate via wireless links

4. Network Model
Connectivity
Edge Length
Interference
Network Model (2)

5. Network Model (3) Log-normal shadowing radio propagation model
Connectivity
Edge Length
Interference
Network Model (3)
Log-normal shadowing radio propagation model

6. Transmission Area - + Connectivity Network Model Edge Length
Interference
Transmission Area - +

7. Connectivity & Node Degree
Network Model
Connectivity
Edge Length
Interference
Connectivity & Node Degree
[Bettstetter, Hartmann 05]
[Stüdi, Chinellato, Alonso 05]

8. Adaptive Power Assignment
Network Model
Connectivity
Edge Length
Interference
Adaptive Power Assignment
Irregular radio propagation improves connectivity.
Similar phenomena known from percolation theory
[Booth, Bruck, Cook, Franceschetti 03] 1
[Jonasson 01], [Roy, Tanemura 02]

9. Distance Distribution
Network Model
Connectivity
Edge Length
Interference
Distance Distribution
[Trott 04]
Edge length distribution Edge power distribution under channel randomness

10. Edge Length Distribution
Network Model
Connectivity
Edge Length
Interference
Edge Length Distribution
Irregular radio propagation increases the average edge length.

11. Network Model
Connectivity
Edge Length
Interference
Interference
Number of interferers: number of nodes that must not send concurrently to a given network link
Studied interference under log-normal shadowing and a power assignment that keeps the expected cumulated noise constant
Log-normal shadowing reduces the number of interferers.
Radio irregularity from log-normal shadowing is beneficial for both connectivity and interference.
A comparable unit disk model is a worst case scenario for connectivity and interference.