Energy-aware Self-stabilizing Multicasting for MANETs

1
Energy-aware Self-stabilizing Multicasting for
MANETs

• Tridib Mukherjee
• IMPACT Lab
• Arizona State University
• impact.asu.edu

2
Mobile Ad hoc Networks (MANETs)

• Network Model
• mobile nodes (PDAs, laptops etc.)
• multi-hop routes between nodes
• no fixed infrastructure

• Applications
• Battlefield operations
• Disaster Relief
• Personal area networking

Multi-hop routes generated among nodes
B

• Network Characteristics
• Dynamic Topology
• Constrained resources
• battery power

C
A
C
A
B
D
D
Links formed and broken with mobility
3
Motivation
MANETs
Dynamic Topology
Energy Constraints
No Fixed Infrastructure
Network Characteristics
Adaptability
Energy- efficiency
Localized Actions
Routing Requirements

• Traditional Routing Protocols
• No action localization
• Routing information exchange across the network.
• Scalability is an issue.

• Two basic types
• Proactive DSDV, TBRPF, IAR, FSR, etc.
• Adaptive but NOT energy-efficient

• Reactive AODV, ODMRP, etc.
• Adaptive Energy-efficient but high latency.

4
Localized Algorithms

• Designed for Sensor Networks
• Data dissemination from sensors in the vicinity
  of actions.
• Does not address mobile nodes
• Can not guarantee adaptability.
• Fixed infra-structure (base station / sink).
• Not Applicable for MANETs.

Activity Sources
Sink
Algorithms for MANETs are not Action Localized
and develop routes to locations where destination
is located.
5
Self-stabilization in Distributed Computing
Topological Changes and Node Failures for MANETs.

• Self-stabilizing distributed systems
• Guarantee convergence to valid state through
  local actions in distributed nodes.
• Ensure closure to remain in valid state until any
  fault occurs.
• Can adapt to topological changes
• Can it be used for routing in MANETs?

Fault
Closure
Invalid State
Valid State
Convergence
Local actions in distributed nodes.
Applied to Multicasting in MANETs
6
Self-stabilizing Multicast for MANETs
Multicast source
Topological Change

• Maintains source-based multi-cast tree.
• Actions based on local information in the nodes
  and neighbors.
• Best effort model.
• Pro-active neighbor monitoring through periodic
  beacon messages.
• Neighbor check at each round (with at least one
  beacon reception from all the neighbors)
• Trigger actions only in case of changes in the
  neighborhood.

Convergence Based on Local actions
How applicable is self-stabilization for MANETs?
Self-Stabilizing Shortest Path Spanning Tree
(SS-SPST)
7
Problems

• Energy-awareness

• Fault diffusion
• improper sequence of node execution
• leads to high stabilization latency
• Fault-containment can reduce latency

Level k - 1
A
B
Level k
C
Level k 1
E
D
G
F
Goal Solve these problems
Level becomes k 2
8
Outline

• Energy Consumption Model
• Protocol Specification
• Fault-containment
• Simulation Study

9
Energy Consumption Model
Ci Ti Ni x R
Cost metric for node i
Transmission energy of node i
Reception cost at all the neighbors

• Variable through Power Control
• One transmission reaches all in range

• Reception energy at intended neighbors.
• Overhearing energy at non-intended neighbors.

intended neighbor
No communication schedule during broadcast in
random access MAC (e.g. 802.11).
Overhearing at j, k, and l
Ci Ti 7R
What is the additional cost if a node selects a
parent?
10
Energy Aware Self-Stabilizing Protocol (SS-SPST-E)

• Actions at each node
• (parent selection)
• Identify potential parents.
• Estimate additional cost after joining potential
  parent.
• Select parent with minimum additional cost.
• Change distance to root.

Loop Detected
E
Not in tree
F
A
B
D
C
X
AdditionalCost (B ? X) TB R
Potential Parents of X
AdditionalCost (A ? X) TA 2R

• Action Triggers
• Parent disconnection.
• Parent additional cost not minimum.
• Change in distance of parent to root.

Select Parent with minimum Additional Cost
Minimum overall cost when parent is locally
selected
Execute action when any action trigger is on
Tree validity Tree will remain connected
with no loops.
11
SS-SPST-E Execution
Multicast source

• No multicast tree
• parent of each node NULL.
• hop distance from root of each node infinity.
• cost of each node is Emax.

2
2
S
A
B
1
2
2
G
3
1
No potential parents for any node.

• First Round source (root) stabilizes
• hop distance of root from itself is 0.
• no additional cost.

1
D
C
H
2
2

• Second Round neighbors of root stabilizes
• hop distance of roots neighbors is 1.
• parent of roots neighbors is root.

Potential parent for A, B, C, D, F S.
E
F
2
AdditionalCost (S ? A, B, C, D) Ts 4R
AdditionalCost (F ? E) TF 2R AdditionalCost
(D ? E) TD 3R
AdditionalCost (D ? E) TD 3R

• And so on

Potential parent for E D, F.
AdditionalCost (S ? F) TS R AdditionalCost (C
? F) TC 3R
AdditionalCost (S ? F) Ts 5R
Potential parent for F S, C.

• Tolerance to topological changes.

Convergence - From any invalid state the total
energy cost of the graph reduces after every
round till all the nodes in the system are
stabilized. Proof - through induction on round .
Closure Once all the nodes are stabilized it
stays there until further faults occur.
12
Stabilization Latency

• Stabilization Latency for SS-SPST-E is O(N).
• Prove by induction on the height of the tree.
• Base Case height is 1
• Only one node (Root Node).
• Stabilization latency O(1).
• Induction Hypothesis height is m
• Total nodes M ?i 1 to m c(i 1).
• Stabilization latency O(M).
• Induction Step height is m 1
• Worst case time to receive beacons from nodes at
  level m is O(cm).
• Stabilization latency is O(?i 1 to m c(i 1)
  cm) O(?i 1 to (m 1) c(i 1) ) O(N).

Number of nodes c1-1 1
height 1
Number of nodes cm - 1
height m
Number of nodes cm
height m 1
13
Fault-containment over SS-SPST-E (SS-SPST-FC)
Select Parent with minimum Additional Cost only
if local action is required

• Local actions are not taken for every action
  trigger.
• Enforce proper sequence of node execution.
• Contains effect of fault
• No fault diffusion.
• Additional information in beacons.
• increases energy consumption.
• Can reduce stabilization latency considerably
• O(N) for SS-SPST-E.
• O(1) for SS-SPST-FC.

Check if local actions in the neighbors can
remove the trigger
Action trigger is on
Level k - 1
A
B
Level k
C
Level k 1
D
E
G
F
14
Simulation Model

• Goals
• performance analysis with beacon reduction.
• study reliability energy-efficiency trade-off.
• scalability study with number of receivers.
• comparative analysis with
• SS-SPST non-energy efficient self-stabilizing
  multicast
• MAODV tree-based multicast
• ODMRP mesh-based multicast
• NS-2 used for simulating 50 nodes placed at
  random positions
• Random way-point mobility model.
• Omni-directional antenna with power control.
• CBR packets _at_ 64Kbps.
• Performance Measures
• Packet Delivery Ratio (PDR) - for reliability
• Energy Consumed / Packet Delivered - for energy
  efficiency

15
Simulation Results Varying Beacon Interval
PDR decreases with less beaconing
16
Simulation Results Varying Beacon Interval
Energy consumption per packet delivered increases
due to decrease in number of packets delivered.
17
Simulation Results Varying Node Mobility
Low packet delivery with high dynamicity
ODMRP has high PDR due to redundant routes
18
Simulation Results Varying Node Mobility
SS-SPST-E leads to energy-efficiency
SS-SPST-FC has higher energy-consumption than
SS-SPST-E
ODMRP has high overhead to generate redundant
routes
19
Simulation Results - Varying Multicast Group Size
Self-stabilizing protocols scale better.
MAODV has highest delay due to reactive tree
construction
20
Simulation Results - Varying Multicast Group Size
ODMRP leads to high control overhead and less PDR.
21
Conclusions Future Work

• SS-SPST-E provides energy-efficiency and action
  localization.
• High adaptability to topological changes.
• SS-SPST-FC further increases packet delivery.
• Decreases stabilization latency.
• SS-SPST-E and SS-SPST-FC lead to
  group-scalability.
• Energy wastage in beaconing if less or no
  multicast traffic.
• Future Work
• Optimizing periodic beacon transmission.
• Applying adaptive localization to other
  energy-efficient multicast (BIP/MIP etc.).

22
References

• Internet Engineering Task Force (IETF) Mobile Ad
  Hoc Networks (MANET) Working Group Charter.
  http//www.ietf.org/html.charters/manet-charter.ht
  ml.
• Q. Zhao, L. Tong. Energy Efficiency of
  Large-Scale Wireless Networks Proactive Versus
  Reactive Networking. IEEE Journal on Selected
  Areas in Communications, Vol. 23, No. 5, May,
  2005.
• E. W. Dijkstra, Self Stabilizing systems in
  spite of distributed control, In Proc.
  Communications of the ACM, November 1974.
• S. K. S. Gupta and P. K. Srimani.
  Self-Stabilizing Multicast Protocols for Ad Hoc
  Networks. Journal of Parallel and Distributed
  Computing, 2003.
• E. Royer and C. E. Perkins. Multicast operation
  of the ad-hoc on-demand distance vector routing
  protocol. In Proc. Of the 5th ACM/IEEE Annual
  Conf. On Mobile Computing and Networking, August
  1999.
• S. Meguerdichian, S. Slijepcevic, V. Karayan, M.
  Potkonjak. Localized Algorithms In Wireless
  Ad-Hoc Networks Location Discovery And Sensor
  Exposure. In 2nd ACM International Symposium on
  Mobile Ad Hoc Networking Computing. 2001
• M. Gerla, S. J. Lee and C. C. Chang. On-Demand
  multicast routing protocol (ODMRP) for ad hoc
  networks. In Proc. Of IEEE Wireless
  Communications and Networking Conference 1999,
  LA, September 1999.
• S. Vaudevan, C. Zhang, D. Goeckel, D. Towsley.
  Optimal Power Allocation in Wireless Networks
  with Transmitter-Receiver Power Tradeoff Proc.
  INFOCOM06, 2006.

23
Questions ???