Title: Reducing Energy Consumption in Human-centric Wireless Sensor Networks
1Reducing Energy Consumption in Human-centric
Wireless Sensor Networks
The 2012 IEEE International Conference on
Systems, Man, and Cybernetics October 14-17,
2012, COEX, Seoul, Korea
Roc Meseguer1, Carlos Molina2, Sergio F. Ochoa3,
Rodrigo Santos4 1Universitat Politècnica de
Catalunya, Barcelona, Spain 2Universitat Rovira i
Virgili, Tarragona, Spain 3Universidad de Chile,
Santiago, Chile 4Universidad Nacional del Sur,
Bahia Blanca, Argentina
2OLSR
Outline
- Motivation
- Potentiality
- OLSRp
- Conclusions Future Work
3Motivation
4Motivation
- Human-Centric Wireless Sensor Networks (HWSN)
- oppnet that uses mobile devices to build a mesh
5Motivation
- Human-centric Sensor Wireless Networks
- Need for maintaining network topology
- Control messages consume network resources
- Proactive link state routing protocols
- Each node has a topology map
- Periodically broadcast routing information to
neighbors
but when the number of nodes is high
6 can overload the network!!!
7OLSR
OLSR Control Traffic and Energy
- OLSR is one of the
- most intensive
- energy-consumers
Traffic and energy do NOT scale !!!
8 can we increase scalability of routing
protocols for Human-centric Wireless Sensor
Networks?
9OLSR
DQ principle
- Data per query Queries per second ?constant
- For routing protocols
- D Size of packets
- Q Number of packets per second sent to the
network - We focus on Q
- Reducing transmitted packets
- Without adding complexity to network management
- HOW?
PREDICTING MESSAGES !!!!
10We propose a mechanism for increasing
scalability of HWSN based on link state
proactive routing protocols
- Called OLSRp
- Predicts duplicated topology-update messages
- Reduce messages transmitted through the network
- Saves computational processing and energy
- Independent of the OLSR configuration
- Self-adapts to network changes.
11Potentiality
12OLSR
Experimental Setup
- NS-2 NS-3
- Grid topology, D 100, 200, 500 m
- 802.11b Wi-Fi cards, Tx rate 1Mbps
- Node mobility
- Static, 0.1, 1, 5, 10 m/s
- Friis Prop. Model
- ICMP traffic
- OLSR control messages
13OLSR
OLSR Messages distribution
Ratio of TC messages is significant for low
density of nodes
14OLSR
Control Information Repetition
Number of nodes does not affect repetition
15OLSR
Control Information Repetition
Density of nodes slightly affects repetition
16OLSR
Control Information Repetition
Repetition is mainly affected by mobility
17OLSR
Control Information Repetition
Repetition still being significant for high node
speeds
18OLSRp
19OLSR
OLSRp Basis
- Prevent MPRs from transmitting duplicated TC
throughout the network
- Last-value predictor placed in every node of the
network - MPRs predicts when they have a new TC to transmit
- The other network nodes predict and reuse the
same TC - 100 accuracy
- If predicted TC ? new TC ? MPR sends the new TC
- HELLO messages for validation
- The topology have changed and the new TC must be
sent - The MPR is inactive and we must deactivate the
predictor
20OLSR
OLSRp Layers
TCWifi ? TCOLSR
if MPR TCOLSR ? TCWifi
if (TCnTCn-1) TCOLSRp ? TCOLSR else TCWifi
?TCOLSR
if MPR? if(TCnTCn-1) TCOLSRp else TCOLSR ?
TCWifi
21OLSR
OLSRp Basis
- Each node keeps a table whose dimensions depends
on the number of nodes - Each entry records info about a specific node
- The nodes _at_IP
- The list of _at_IP of the MPRs (O.A.) that announce
the node in their TCs and the current state of
the node (A or I). (HELLO messages received). - A predictor state indicator for MPR nodes (On or
Off) - On when at least one of the TC that contains
information about the MPR is active - Off when the node is inactive in all the
announcing TC messages (new TC message will be
sent)
22OLSR
Experimental Setup
- NS-2
- Physical area of 200m X 200m
- 25 stationary nodes 275 mobile nodes
- Nodes are randomly deployed (11 simulations)
- All nodes assume IPhone 4 features
- Mobile nodes assume
- random mobility and
- walking speed (0.7m/s)
- Wifi Channel assumes Friis Propagation loss model
- OLSR control messages HELLO2s TC5s
- Data traffic assumes UDP packets transmitted
every second
23OLSR
OLSRp Benefits
- Reduction in energy consumption
24OLSR
OLSRp Benefits
- Reduction in control traffic CPU processing
25Conclusions Future Work
26OLSR
Conclusions Future Work
- Conclusions
- OLSRp has similar performance than standard OLSR
- Can dynamically self-adapt to topology changes
- Reduces network congestion
- Saves computer processing and energy consumption
- Future Work
- Further evaluation of OLSRp performance
- Assessment in real-world testbeds
- Application in other routing protocols
27Questions?
The 2012 IEEE International Conference on
Systems, Man, and Cybernetics October 14-17,
2012, COEX, Seoul, Korea
Thanks for Your Attention
28 The 2012 IEEE International Conference on
Systems, Man, and Cybernetics October 14-17,
2012, COEX, Seoul, Korea
Questions?
29ANEXOS
30OLSR
OLSRp Example
B
B
31OLSR
OLSRp Example
B
B
NODE D TABLE
32OLSR
OLSRp Example
X
B
B
NODE D TABLE
33OLSR
OLSRp Example
X
B
B
NODE D TABLE
34OLSR
OLSRp Example
X
B
B
NODE D TABLE
35OLSR
OLSRp Other Results
36OLSR
OLSRp Other Results
37OLSR
OLSRp Other Results