The Energy Cost of Control Packets in Hybrid MAC Protocols

1. Chair of Computer Networks, Faculty of Computer Science The Energy Cost of Control Packets in Hybrid MAC Protocols Qian Dong, Waltenegus Dargie, Alexander Schill Technical University of Dresden Dresden, 01062, Germany {qian.dong, waltenegus dargie. alexander schill}@tu-dresden.de

2. Outline • Motivation • Description of hybrid MAC protocol • Overlap neighbor model • Extra energy model with control packets • Energy model for the RTS and CTS packets • Energy model for overhearing the RTS and CTS packets • Energy model for the sleep period • Energy model for switching the radio mode • Extra energy model without control packets • Energy model for 1st fragment retransmission due to collision • Energy model for overhearing 1st fragment and ACK packets • Energy model for idle listening • Energy model for switching the radio mode • Conclusion

3. Motivation • Control packets, can avoid collision and overhearing, however, bring a large amount of energy cost themselves. • Analyze the trade-off between the energy costs introduced when control packets are activated and when they are deactivated, from the perspective of sampling rate.

4. 1. SMAC as an example 1.1 With and without control packets Description of hybrid MAC protocol 1.2 Working principle of SMAC

5. Description of SMAC

6. Energy model in the situation with control packets 2.Overlap neighbor model

7. 1 Energy model for RTS and CTS packets Energy model in the situation with control packets 1.1 Transmission energy model of RTS and CTS packets 1.2 Reception energy model of RTS and CTS packets 1.3 Total average energy model of RTS and CTS packets

8. 2 Energy model for overhearing the RTS and CTS packets Energy model in the situation with control packets 2.1 Energy model of the RTS overhearing 2.2 Energy model of the CTS overhearing 2.3 Total average energy model of overhearing

9. 3 Energy model for the sleep period Energy model in the situation with control packets

10. 3.1 Energy model of the extra sleep by the neighbors of i Energy model in the situation with control packets 3.2 Energy model of the extra sleep by the left neighbors of j 3.3 Total average energy model of the extra sleep

11. 4.Energy model for switching the radio mode Energy model in the situation with control packets

12. Energy model in the situation with control packets

13. Energy model in the situation with control packets 4.1 Energy model for switching the radio mode between i & j 4.2 Total average energy model for switching the radio mode

14. 1. Energy model for 1st fragment retransmission due to collision 1.1 Communication energy model of the first data fragment Energy model in the situation without control packets 1.2 Communication energy model of the first collision-free data fragment 1.3 Energy model for 1st fragment retransmission due to collision

15. 2 Energy model for overhearing 1st fragment and ACK packets Energy model in the situation without control packets 2.1 Energy model for overhearing the 1st fragment 2.2 Energy model for overhearing the first ACK packet 2.3 Total energy model for overhearing 1st fragment and ACK packets

16. Energy model in the situation without control packets 3 Energy model for idle listening

17. Energy model in the situation without control packets

18. Energy model in the situation without control packets 4 Energy model for switching the radio mode

19. Simulation 1. Overall energy costs with and without control packets

20. Conclusion • Sampling rate highly influences the energy consumption of hybrid MAC protocols regardless of control packets. • Two lines representing the energy costs with and without control packets never intersect. • Energy is consumed less in the situation with control packets than that without. • Hybrid MAC protocols perform better when control packets are adopted.

21. Simulation 2. Comparison of energy costs with and without control packets