The GreenStriking a Balance between QoS and
Energy SavingEnergy Saving
Aruna Prem Bianzino1, Claude Chodet
The Green-Game: Striking a Balance between QoS and
Energy Saving
08.09.2011
Energy Saving
, Claude Chodet1, Stefano Moretti2, Dario Rossi1, Jean-Louis Rougier1
1. Telecom ParisTech, 2. Université Paris-Dauphine
Introduction: ICT for Green
• Information and Communication Technologies (ICT) offer big opportunities to reduce the human footprint:
- Videoconferences, telepresence, email, etc.
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Introduction: ICT for Green
Information and Communication Technologies (ICT) offer big opportunities to reduce the human footprint:
Videoconferences, telepresence, email, etc.
08.09.2011
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Introduction: Green for ICT
• ICT itself represents a strong contributionenvironmental impact of human activities, and with a very high increasing rate:
- Same footprint of the airplane transports,
… but with higher growing rate.… but with higher growing rate.
Remark: our work focusses on “energy aware
Gas emission is complex to quantify (type of energy, …)
Economical arguments (reduce energy cost)
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Introduction: Green for ICT
strong contribution to the environmental impact of human activities, and with a very
Same footprint of the airplane transports,
… but with higher growing rate.
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… but with higher growing rate.
energy aware” ICT
Gas emission is complex to quantify (type of energy, …)
Economical arguments (reduce energy cost)
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Green for ICT: A Hot Topic
Many works have been initiated in the last years:In Data Centers, in Peripherals
• In wireless networks, not completely a subject:
- Battery constraints in wireless mesh/sensor networks- Interferences (power control)- Important savings
• In wired networks:- Still some interesting opportunities - Depend on topologies
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Green for ICT: A Hot Topic
Many works have been initiated in the last years:Peripherals, and in Networks:
, not completely a “new”
Battery constraints in wireless mesh/sensor
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Interferences (power control)
Still some interesting opportunities Depend on topologies
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Energy Saving Opportunities
Facts:- Network systems and devices are - Predicable traffic fluctuations
- Today: energy agnostic equipments- How to reach proportionality (energy/utilization)
Utilisation
Pow
er c
onsu
mpt
ion
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Energy Saving Opportunities
Network systems and devices are over-provisionedfluctuations
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Today: energy agnostic equipmentsHow to reach proportionality (energy/utilization)
WorstIntermediateIdeal
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Resource Consolidation
- Already a popular practice in other domains(e.g., Data Centers)
Traffic
- Traffic aggregation through a proper
Time
Traffic
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Resource Consolidation
Already a popular practice in other domains
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Traffic aggregation through a proper weight optimization.
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Resource Consolidation: Open Points
- A solution purely optimizing the energy consumption does not take into account the
- There is no control on which network elements are switched off
- Definition of a criticality index - Definition of a criticality index devices to drive the resource consolidation process
Definition of a trade off between
Energy-saving
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Resource Consolidation: Open Points
A solution purely optimizing the energy consumption does not take into account the system robustness
There is no control on which network elements are
criticality index for the network
08.09.2011
criticality index for the network devices to drive the resource consolidation process
Definition of a trade off between
saving and robustness
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A Game-Theoretical Approach
- The basic idea:
• Modeling the communication network as a cooperative TU-game
• Each node is a player
• Every coalition is a network configuration:
- Nodes in the coalition
- Other nodes -> OFF (or failures)
• The amount of delivered traffic is the revenue of the coalition
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Theoretical Approach
Modeling the communication network as a
08.09.2011
Every coalition is a network configuration:
Nodes in the coalition -> ON
OFF (or failures)
The amount of delivered traffic is the revenue of
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A Game-Theoretical Approach (2)
- The final game is the composition of two games:
• A Traffic Game (A-Priori) over a full(allows all coalitions, accounts only for the Traffic Requests)
• A Topology Game (A-Posteriori), which is the • A Topology Game (A-Posteriori), which is the restriction of the first over the network graph, and accounts for the Topology
• The two games may be decomposed into several unanimity games
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Theoretical Approach (2)
The final game is the composition of two games:
Priori) over a full-mash network (allows all coalitions, accounts only for the Traffic
Posteriori), which is the
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Posteriori), which is the restriction of the first over the network graph, and accounts for the Topology
The two games may be decomposed into several
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The Shapley Ranking
- The Shapley value defines a rank among players (on the basis of the amount of traffic that nodes contribute to carry, and of their criticality while composing the coalition)
- Nodes are progressively switched off (if the all traffic - Nodes are progressively switched off (if the all traffic requests are still satisfied, with eventual maximum load constraints)
- When to stop?
CF A
Lower Shapley
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
The Shapley Ranking
defines a rank among players (on the basis of the amount of traffic that nodes contribute to carry, and of their criticality while composing the
Nodes are progressively switched off (if the all traffic
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Nodes are progressively switched off (if the all traffic requests are still satisfied, with eventual maximum load
B D E
Higher Shapley
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The Shapley Ranking: Toy Cases
1)
2) D
B
A
3)
C
DA
B
CE
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The Shapley Ranking: Toy Cases
Every node has the same Shapley value
A, D -> 5/12
C, B -> 1/12
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->
A, D -> 23/60
B -> 8/60
C, E -> 3/60
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Other Possible Rankings
- Other criticality indexes are present in the literature, but all of them only account for the network topology
- The G-Game considering an uniform TM matches quite well these indexes, but there is low correlation when taking into account the Trafficwhen taking into account the Traffic
G-Game (U-TM) Betweenness Degree
G-Game (U-TM) 1
Betweenness 0.9688 1
Degree 0.4594 0.5321 1
Closeness 0.8729 0.9057 0.6216
Eigen -0.0073 0.0792 0.7335
G-Game 0.4085 0.4286 0.2527
Traffic Load 0.4251 0.4868 0.4762
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Other Possible Rankings
Other criticality indexes are present in the literature, but all of them only account for the network topology
Game considering an uniform TM matches quite well these indexes, but there is low correlation when taking into account the Traffic
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when taking into account the TrafficCloseness Eigen G-Game Traffic
Load
1
0.1787 1
0.5132 -0.0220 1
0.6046 0.1911 0.5583 1
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A Real Case Study: The Network Scenario
- TIGER2 Network (typical access/metro network)
- Access nodes (traffic Sources - Access nodes (traffic Sources and Destinations)
- Core nodes (only traffic transport)
i
j
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
A Real Case Study: The Network Scenario
TIGER2 Network (typical
nodes (traffic Sources
1 6
78
9
1 0 1 8
1 9 2 02 1
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nodes (traffic Sources
2
3
1 3
4
51 6
1 1
1 2
1 4 1 5
1 7T
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A Real Case Study: Different Rankings
1 6
78
9
1 0
1 1 1 7
1 8
1 9 2 02 1
T
2
3
1 3
4
51 6
1 1
1 2
1 4 1 5
1 7T
Only Topology
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
A Real Case Study: Different Rankings
T1 1
1 8
1 91 6
78
9
1 0
1 7
2 02 1
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T1 1
1 2
2
3
1 3
4
51 6
1 4 1 5
1 7
G-Game
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A Real Case Study: Results
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
A Real Case Study: Results S U L
9 5 9
15 9 15
13 14 8
14 20 7
16 21 5
21 15 4
11 13 21
10 11 20
20 10 2
19 4 3
17 16 1
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17 16 1
18 19 6
12 6 14
8 1 11
5 12 10
7 17 19
4 8 16
3 T 13
6 7 12
1 3 17
2 18 18
T 2 T
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A Real Case Study: Results (2)
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Per
cent
age
of li
nk
Order Shapley
Energy saving (%) 17.05
Weighted avg path length 2.99
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
0
5
10
[0-10)[10-20)[20-30)[30-40)[40-50)[50-60)
Per
cent
age
of li
nk
Link load (%)
A Real Case Study: Results (2) S U L
9 5 9
15 9 15
13 14 8
14 20 7
16 21 5
21 15 4
11 13 21
10 11 20
20 10 2
19 4 3
17 16 1
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U-TMLoad
ShapleyReference
17 16 1
18 19 6
12 6 14
8 1 11
5 12 10
7 17 19
4 8 16
3 T 13
6 7 12
1 3 17
2 18 18
T 2 T
U-TM Load
13.43 16.27
3.40 3.25
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[50-60)[60-70)[70-80)[80-90)[90-100]
Link load (%)
G-Game: Future Work
- Evaluation of the impact of:
• different scenarios (topology and TM), to highlight dependences
• different energy models (e.g. optical transmission, with periodical signal regeneration)with periodical signal regeneration)
- Evaluation of the effects on the inter(hot potato)
- Integration with dynamic routing protocols (IGP Weight Optimization)
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Game: Future Work
Evaluation of the impact of:
different scenarios (topology and TM), to highlight
different energy models (e.g. optical transmission, with periodical signal regeneration)
08.09.2011
with periodical signal regeneration)
Evaluation of the effects on the inter-domain routing
Integration with dynamic routing protocols (IGP
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Thank you!
Further details at:perso.telecom
Thank you!
Further details at: [email protected]/~bianzino
The G-Game: An Example
1)
2)
D
C
B
A
B2)
3)
D
C
B
A
D
C
B
A
The 23rd International Teletraffic Congress - ITC 2011 - San Francisco, USA
Game: An Example
Traffic Request
A -> D: 50Mbps
Traffic Game:
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Traffic Game:
v = u(A, D)
Topology Game:
Minimal connected components containing A, D:
vΓ = u(A,B,D)+u(A,C,D)-u(A,B,C,D)
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Energy Saving Opportunities
Politecnico di Torino, Italy 29/06/2010
Energy Saving Opportunities
6/27Politecnico di Torino, Italy 29/06/2010
EAR: An Optimization Approach
-Modeling the device energy consumption as a function of the utilization level
- ILP formulation for a - ILP formulation for a minimum-energy routing
Politecnico di Torino, Italy 29/06/2010
- Evaluation over different network scenarios (i.e., topologies and traffic matrixes)
- Accounting for QoS: maximum imposable link load
EAR: An Optimization Approach
the device energy consumption as a function of
9/27Politecnico di Torino, Italy 29/06/2010
Evaluation over different network scenarios (i.e., topologies and traffic matrixes)
Accounting for QoS: maximum imposable link load
EAR: Results
- The solution has been tested over the GEANT2 network with real traffic matrixes
- All nodes generate/receive traffic (unfriendly scenario)traffic (unfriendly scenario)
Politecnico di Torino, Italy 29/06/2010
The solution has been tested over the GEANT2 network
All nodes generate/receive traffic (unfriendly scenario)traffic (unfriendly scenario)
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EAR: Results (3)
Politecnico di Torino, Italy 29/06/2010
• The work has been finalized in:
- A.P. Bianzino, C. Chaudet, F. Larrocca, D. Rossi, J.submitted to GreenComm3 (GLOBECOM), Florida, USA,
- A.P. Bianzino, C. Chaudet, D. Rossi, J.-L. Rougier, Charge Network Flow Formulation”, in ACM SIGCOMM e2010.
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IGP-WOGreen (α=0.75)
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0
5
10[0]
(0-10](10-20](20-30](30-40](40-50](50-60](60-70](70-80](80-90](90-100]
Per
cent
age
of li
nk
Link load (%)
A.P. Bianzino, C. Chaudet, F. Larrocca, D. Rossi, J.-L. Rougier, “Energy-Aware Routing: a Reality Check”, Florida, USA, Dec. 2010.
L. Rougier, “Energy-Awareness in Network Dimensioning: a Fixed ACM SIGCOMM e-Energy'10, Extended Abstract, Passau, Germany, April
EAR: What is next?
• Formulation:
- Use of approximate solutions
- Comparison with existing heuristics
• Refinement of the model:
- Evaluation of the robustness of the solution
Politecnico di Torino, Italy 29/06/2010
- Evaluation of the robustness of the solution
- Considering optical transmission: periodical signal regeneration, thus length dependent energy consumption
• Result Analysis:- Impact of Topology: Considering a broader set of scenarios (topologies, and TMs)
- Evaluation of the effects on the inter
Use of approximate solutions
Comparison with existing heuristics
Refinement of the model:
Evaluation of the robustness of the solution
13/27Politecnico di Torino, Italy 29/06/2010
Evaluation of the robustness of the solution
Considering optical transmission: periodical signal regeneration, thus length dependent energy consumption
Impact of Topology: Considering a broader set of scenarios (topologies, and TMs)
Evaluation of the effects on the inter-domain routing
Other Interesting Solutions: ALR
- Automatic adaptation of the link rate to its real utilization
- Different possible algorithms, different possible states/rates
S
states/rates
- A comparison is missing
- Evaluation of the interactions with the TCP congestion control
- Evaluation of the effects on the QoS
Politecnico di Torino, Italy 29/06/2010
Other Interesting Solutions: ALR
Automatic adaptation of the link rate to its real
Different possible algorithms, different possible
DL
Evaluation of the interactions with the TCP
Evaluation of the effects on the QoS
24/27Politecnico di Torino, Italy 29/06/2010
Other Interesting Solutions: Proxying
- AEx: ARP, BitTorent, …
- Allows terminals to enter into sleep mode
Politecnico di Torino, Italy 29/06/2010
Other Interesting Solutions: Proxying
Allows terminals to enter into sleep mode
A1Politecnico di Torino, Italy 29/06/2010