1. Adaptation of TDMA Parameters Based on Network Conditions Bora KARAOGLU

2. Agenda  PHY Layer Abstraction  Protocol Overview  Analytical Analysis  Dropped Packets  Collisions  Proof of Concept  Optimization of TDMA parameters

3. Agenda  PHY Layer Abstraction  Protocol Overview  Analytical Analysis  Dropped Packets  Collisions  Proof of Concept  Optimization of TDMA parameters

4. PHY Layer Abstraction  BW  Each tx occupies some part of the BW  Transmissions should overcome any noise present in the space of the BW  Divide  Spatial reuse

5. PHY Layer Abstraction  TDMA:  Divide BW along time axis  Clustering:  Distribute parts of BW spatially among clusters

6. Agenda  PHY Layer Abstraction  Protocol Overview  Analytical Analysis  Dropped Packets  Collisions  Proof of Concept  Optimization of TDMA parameters

7. Protocol Overview  TDMA  Soft Clustering  CHs responsible for channel access only  Inter cluster communication is allowed  TDMA  Soft Clustering  CHs responsible for channel access only  Inter cluster communication is allowed

8. Agenda  PHY Layer Abstraction  Protocol Overview  Analytical Analysis  Dropped Packets  Collisions  Proof of Concept  Optimization of TDMA parameters

9. Analytical Analysis  Shortcomings of Simulations  Substantial Processing Power and Time  Repetitions for statistical accuracy  Valid only for the parameters set used  Scalability of Simulation Area  Edge Effects  Shortcomings of Simulations  Substantial Processing Power and Time  Repetitions for statistical accuracy  Valid only for the parameters set used  Scalability of Simulation Area  Edge Effects

10. Analytical Analysis  Factors limiting performance:  Dropped Packets  Real-time communication  Limited Local Capacity  Clustering  Uneven distribution of Load  Node Distributions  Mobility  Collisions  Spatial Reuse  Limited BW Divisions

11. Dropped Packets  Probability of Dropping a Packet  Capacity per Cluster:  Number of Data Slot per Frame  Nonlinear relation between Load and P dp  Detailed probability distribution of Load is needed

12. Dropped Packets  p s : Probability of a node to be in spurt duration  p A : Probability of a node to be in the communication range of a CH  p d : Probability of a node that is in the communication range of a CH to choose that CH as its channel access provider  Independent of Node Density  assumed constant

13. Dropped Packets  p s : Probability of a node to be in spurt duration  p A : Probability of a node to be in the communication range of a CH  p d : Probability of a node that is in the communication range of a CH to choose that CH as its channel access provider p dn = p s p A p d

14. Collisions  Number of frames (N f ) vs. co-frame CH separation(d ch )  Labeling structure used in cellular systems

15. Collisions  co-frame CH separation (d ch ) vs. number of collisions ( f coll )

16. Collisions  co-frame CH separation (d ch ) vs. number of collisions ( f coll )  N nCH : Expected number of nodes in the cluster  N n : Total number of nodes  N C : Number of cluster in 2*r comm range  V : Region bounded by the circle with radius 2*r comm around origin  fcoll : number of packets lost per SF due to collision

17. Agenda  Soft Clustering Approaches  Protocol Overview  Analytical Analysis  Dropped Packets  Collisions  Proof of Concept  Optimization of TDMA parameters

18. Proof of Concept  Total Number of Packets Lost per Superframe

19. Proof of Concept  RX Throughput per Superframe

20. Agenda  Soft Clustering Approaches  Protocol Overview  Analytical Analysis  Dropped Packets  Collisions  Proof of Concept  Optimization of TDMA parameters

21. Optimization of TDMA parameters

22. Other Uses of the Model  Instantaneous Analysis Results for changing  Transmission Power  Propagation Model  PHY Specs: Freq, Threshold values …  Asymptotic Behavior  Energy Consumption  Average node sleep/awake durations  Average energy consumption per node  Node and CH comparison wrt energy consumption  Optimization of Nf wrt energy consumption

23. Throughput Per Node

24. Energy Consumption per Node

25. Thanks! Questions&Comments? Thanks! Questions&Comments?