1. A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol
Presented by : Frédéric CHALLITA-Cedric CHAUVENET-Andreas BRUNSCHWEILER
10/01/2016

2. SUMMARY Introduction and project context
G3 PLC LOADng routing protocol
Theoretical comparison between metrics
nSim G3 simulator
Simulation results
Conclusion and perspectives
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A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

3. 01
Introduction

4. Context of the project
Evolution of the current electrical network into smart grids
Integration of information and telecommunications theory
The client becomes an actor not only a consumer
Linky project : promotes smart metering by using an interesting technology  PLC or Power Line Communications
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

5. Context of the project
Narrowband for Smart Metering applications : CENELEC A : 33 till 90 kHz
Physical layer : OFDM (Orthogonal frequency division Multiplexing )
Channel Access managed in MAC layer by CSMA/CA
Our focus in the Linky project is on the CENELEC A band dedicated to these use cases.
The physical layer is commanded by the OFDM. This technique permits the simultaneaous transmission of different symbols without interference.
Given that many meters want to send messages, the mangement an organisation of the channel access is important. This job is affected to the MAC layer.
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

6. G3 PLC LOADng routing protocol01
G3 PLC LOADng routing protocol

7. G3 PLC LOADng routing
Multitude of possible routes, RREQ, RREP, Route Costs, Route choices.
Route breakage  Route Repair mechanism is triggered, and this operation will generate a flooding in the network
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

8. Importance of routing
Hostile propagation channel : time variable, frequency selective and dependent on the electrical equipment  Impedance variation
Unpredictability of the created links caused by the variation of the channel’s impulse response.
Many possible routes, many criteria to take into account
Routing metrics: quantitative assessment that provides a cost for evaluating the path between communicating nodes
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

9. 01
Routing metrics
To this purpose we need mathematical functions that will help us choose the optimal path. A routing metric is a quantative evalauation of the link based on criterion.

10. Routing metrics
Composite contains many factors to take into account : LQI (adpKq=10)), modulation, number of hops (adpKh=4), number of active tones . 𝑅𝑜𝑢𝑡𝑒𝐶𝑜𝑠𝑡=10∗ 255−𝐿𝑄𝐼
Capacity associates route costs to each couple (modulation/nb. of active tones)
Alternative configuration of the default Composite by setting adpKr=20 (for ROBO mode).
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

11. Evolution of Route Cost
We can see a great dynamic range for route costs in the case of the Capacity metric and we can also see that this metric penalises the ROBO mode sensitive to impulsive noises…
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

12. Aspects of the Composite metric
If 0<LQI<255  4<RC<14 .
LQI limit of ROBO mode=52  RC=12
LQI max observed = 140  RC=9 : perfect link
Small range between ROBO and perfect link
This fact can priviliege routes with ROBO links rather than routes with 2 hops D8PSK links because 2*9 > 12
If we had the whole range of LQI  2*4<12
ROBO modulation is sensitive to impulsive noise and random attenuations affecting the propagation channel
These facts justify the promising use of Capacity metric
It will associate a higher route cost for ROBO mode.
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

13. Dynamic range of SNR for different modulations
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

14. 01
nSim G3 Simulator

15. Presentation Dedicated to the simulation of the G3 specification
User friendly graphical interface with simple configuration of the propagation channel
Configuration of noise, attenuation, sub-carriers, etc.
Possibility to change MAC, ADP, PHY parameters and test their influence
Our goal : test the performances of the different routing metrics
Validation
Comparison with lab results
Comparative study of routing metrics
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

16. 01
Simulation results

17. Topology and results
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

18. Average RTT time
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

19. 01
Conclusion

20. Conclusion and perspectives
Enhanced performances measured with the capacity metric or alternative routing configuration of composite metric in different aspects
Success rate without droprate
Success rate with droprate
Average throughput (≈50% better)
Interdependence between the different layers leads to the optimization of the CSMA/CA ( extension of the contention window)
Testing the new parameter set of the Composite metric in real field conditions
A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol – 11/9/2016

21. A Comparative Study of Routing Metrics in G3-PLC LOADng routing protocol
Presented by : Frédéric CHALLITA-Cedric CHAUVENET-Andreas BRUNSCHWEILER
10/01/2016