A survey on Wireless Sensor Networks

(WSNs)

Ciro Sirignano

PRESENTATION OUTLINE

A SURVEY ON WSNs :

STEP 1 - IMPORTANT WSN ISSUE STEP 2 - ENERGY EFFICIENT TECHNIQUESSTEP 3 - CLASSIFICATION OF ENERGY

AWARE MAC PROTOCOL

MOBILITY MODEL :

STEP 1: ENTITY – GROUP STEP 2: BEST CHOICE IN EACH SCENARIO

STEP 1

A SURVEY ON WSNs

IMPORTANT WSN ISSUE PLANNING KEY

APPLICATION FIELDPERSONAL (HOME)COMMUNUTY (AGRICOLTURE, POLLUTION, HEALTH)INDUSTRIAL (MILITARY, FOOD PROCESSING)

ENVIRONMET

SERVICE FEATURES:NETWORK LIFETIMEENERGY EFFICIENCYCONNECTIVITY AND COVERAGELINK QUALITY COMMUNICATIONRELIABILITY AND AVAILABILITY

STEP 1

THESE FACTORS ARE IMPORTANT, THEY SERVE AS A GUIDELINE TO DESIGN A PROTOCOL OR AN

ALGORITHM FOR SENSOR NETWORKS.

A SURVEY ON WSNs

APPLICATION FIELDS

ENVIRONMENTSERVICE FEATURES

WSN DESIGN

WE TAKE ACCOUNT THE FACTORS:

FAULT TOLLERANCESCALABILITYPRODUCTION COSTS OPERATING ENVIRONMENT SENSOR NETWORK TOPOLOGYHARDWARE CONSTRAINTS TRANSMISSION MEDIAPOWER CONSUMPTION

STEP 1

A SURVEY ON WSNs

EXAMPLE : ZigBeeBUILDS UPON IEEE 802.15.4 STANDARDHIERARCHICAL ORGANISATIONCLUSTER TREE TOPOLOGY/MESH TOPOLOGYMULTI-HOP TRANSMISSION

STEP 1

A SURVEY ON WSNs

ENERGY EFFICIENCYPROBABLY MOST IMPORTANT WSN ISSUE

SOURCES OF ENERGY CONSUMPTION ARE:WIRELESS INTERFACE CPU PROCESSING

SOURCE ENERGY WASTE:IDLE LISTENINGCOLLISIONSOVERHEARINGPROTOCOL OVERHEADTRAFFIC FLUCTUATION

STEP 2

A SURVEY ON WSNs

APPROACHES TO ENERGY SAVING: TAXONOMY OF APPROACHES TO ENERGY SAVING

STEP 2

A SURVEY ON WSNs

THREE MAIN TECHNIQUES:DUTY-CYCLINGDATA-DRIVENMOBILITY-BASED

LEAVING OUT DATA-DRIVEN AND MOBILITY SCHEMES DETAILS

APPROACHES TO ENERGY SAVING:

STEP 2

A SURVEY ON WSNs

DETAILED TAXONOMY OF DUTY CYCLING SCHEMES

STEP 2

A SURVEY ON WSNs

ENERGY CONSERVATION SCHEMES

TOPOLOGY CONTROLLOCATION-DRIVE

GAF (Geographical Adaptive Fidelity)GERAF (Geographic Random Forwarding)

CONNECTIVITY-DRIVEN SPANASCENT

TOPOLOGY CONTROL SHOULD BE COUPLED WITH OTHER KINDS OF ENERGY

CONSERVATION TECHNIQUES.

STEP 2

A SURVEY ON WSNs

ENERGY CONSERVATION SCHEMES

POWER MANAGEMENTSLEEP/WAKEUP PROTOCOLS

ON-DEMAND SCHEMES STEM (Sparse Topology and Energy MGMT)

PTW (Pipelined Tone Wakeup)SCHEDULED RENDEZVOUS SCHEMESASYNCHRONOUS SCHEMES

TRADE-OFF: THE APPROACH ON DEMAND PROTOCOLSIS THE IDEAL ONE BUT ALWAYS IMPRACTICALANOTHER (RENDEZVOUS AND ASYNC. SCHEMES)SOLUTION INCREASED LATENCY OR REQUIRE NODE SYNCHRONIZED

STEP 3

A SURVEY ON WSNs

MAC PROTOCOL WITH LOW DUTY-CYLETDMA-BASED

TRAMAFRAMALMAC

CONTENTION-BASED MAC PROTOCOLB-MAC AND LPLS-MACT-MAC

HYBRID MAC PROTOCOLSPROBABILISTIC TDMAZMAC

CLASSIFICATION ENERGY AWARE MACPROTOCOL

STEP 3

A SURVEY ON WSNs

CLASSIFICATION ENERGY AWARE MACPROTOCOL

2002

2003

2004

2005

2001

2000

TDMA-BASEDCONTENTIONHYBRID

TRAMA

LMAC

FRAMA

SMAC

TMAC

DMAC B-MAC

PTDMA ZMAC

STEP 3

A SURVEY ON WSNs

CLASSIFICATION ENERGY AWARE MACPROTOCOL

TDMA-BASED ADVANTGES: COLLISION-FREE PROTOCOL NO IDLE LISTENING OR OVERHEARING WEAKNESSES: LOW SCALABILITYCOMPLEX TO MANAGE IN VERY POPULATED NETWORKBECAUSE TIME SYNCHRONIZATION IS NEEDED

CONTENTION-BASEDADVANTAGES: SCALABLE, NO COMPLEX SETUPNO SYNCHRONIZATION NEEDEDWEAKNESSES: COLLISION PROBABILITY, ENERGY WASTAGE COLLISIONS, IDLE LISTENING

HYBRIDADVANTAGES: ADAPT TO TRAFFIC FLUCTUATIONWEAKNESSES: THE USE OF SLOTTING CONCETRATE MOST OF CONNECTION ATTEMPTS TO THE BEGINNINGOF SLOTS

STEP 3

A SURVEY ON WSNs

COMPARISON BETWEEN ENERGY AWARE MAC PROTOCOL

COMPARISON: LOW POWER LISTENINGS-MACT-MACLMAC

EXPERIMENTS TIPOLOGY :NODES ISOLATION (EMPTY WORKLOAD)ALL NODES IN NETWORK

STEP 3

A SURVEY ON WSNs

COMPARISON BETWEEN ENERGY AWARE MAC PROTOCOL

NODES ISOLATION EXPERIMENT:ORGANIZATIONAL ENERGY CONSUMPTIONMULTI-HOP LATENCY (EMPTY NETWORK)

STEP 3

A SURVEY ON WSNs

COMPARISON BETWEEN ENERGY AWARE MAC PROTOCOL

NODES ISOLATION EXPERIMENT:MAX THROUGHPUT THAT SINGLE NODE CAN HANDLE

STEP 3

A SURVEY ON WSNs

COMPARISON BETWEEN ENERGY AWARE MAC PROTOCOL

NETWORK PERFORMANCE UNDER:HOMOGENEOUS UNICAST TRAFFICHOMOGENEOUS BROADCAST TRAFFICLOCAL GOSSIPCONVERGECAST

INTENSITY WAS CONTROLLED BY ADJUSTING THE SENDIG RATE OF THE NODES (PAYLOAD)

THE GRAPHES SHOW DELIVERY RATIO / PAYLOADENERGY CONSUMPTION / PAYLOADENERGY PER BIT / PAYLOAD

STEP 3

A SURVEY ON WSNs

COMPARISON BETWEEN ENERGY AWARE MAC PROTOCOL

COMPARISON REVEALED THAT THERE IS NO SINGLE BEST MAC PROTOCOL THAT OUTPERFORMS ALL OTHERS.

ADAPTIVITY IS MANDATORY TO HANDLE THE LOCAL GOSSIP AND CONVERGECAST COMMUNUCATION PATTERNS :

T-MAC AND LPL ARE NOT THE FINAL ANSWER, THEY SUFFER FROM CONTENTION COLLAPSE

COLLISION AVOIDANCE CONSIDERED PROHIBITIVE:THE RTS/CTS REDUCE THE EFFECTIVE CHANNEL CAPACITY WITH COMMUNICATION GROUPING

COMMUNICATION GROUPING CONSIDERED HARMFULLMAC IS RATHER ROBUST AND PERFORMANCE DEGRADES GRAFULLY UNDER HIGHER LOADS

MOBILITY MODEL

TYPE OF MOBILITY MODEL:

Traces modelSynthetic model

SYNTHETIC MODEL:Random Walk Random Waypoint Random Direction A Boundless Simulation Area Gauss- Markov A Probabilistic Version of the Random Walk

MOBILITY MODEL

IMPORTANCE OF CHOOSING AN APPROPRIATE M.M.

PERFORMANCE RESULTS SIGNIFICANTLY CHANGE WHEN THE M.M. IS CHANGED

MOBILITY MODEL

RANDOM WALK

MN Moves from-to

Choose a direction [0, 2π] and speed [speedmin,speedmax]. Each step with costant interval t or in costant distance d.

Memoryless mobility pattern ~ Unrealistic movements

Sudden stops and sharp turns

MOBILITY MODEL

RANDOM WAYPOINT

Is similar to the Random Walk M.M. But there is the time-break interval between two MN travels.

The initial distribuited randomly around the simulation area is not rappresentative of the manner in which nodes distribuite themselves when moving

A multicast protocol in ad hoc network

MOBILITY MODEL

RANDOM DIRECTION

Is similar to Random Walk Mobility Model

MN choose a random direction in which to travel similar to the Random Walk M.M.

When the border is reached a MN pauses for a specified time, choose another angular direction and continues the process

MOBILITY MODEL

A BOUNDLESS SIMULATION AREA

In this model Exists a relationship between previous and current direction.A velocity vector v=.(v,θ)

The MN that reach one side of simulation area reappear on the opposite side of simulation area.

MOBILITY MODEL

GUASS-MARKOV

Initially each MS is assigned a current speed and direction. The value of speed and direction at the n_th is calculate based upon the value of spedd and direction at the (n-1)_th,

Where s and d are velocity and direction. The parameter with upperscrore are the mean value.

Alfa[0,1]is the parameter used to vary the randomness.

MOBILITY MODEL

A PROBABILISTIC VERSION OF RANDOM WALK

Utilizes a probability matrix to determine the position of a particular MN in the next time step.

Choosing a appropiate values of P(a,b) may prove diffult.

GROUP MOBILITY MODEL

GROUP MOBILITY MODEL:

It necessary to model the behavior of Mns as they move togheter

EXPONENTIAL CORRELATED RANDOM M.M.COLUMN M.M.NOMADIC COMMUNITY M.M.PURSUE M.M.REFERENCE POINT GROUP M.M-

GROUP MOBILITY MODEL

- COLUMN

- NOMADIC COMMUNITY

GROUP MOBILITY MODEL

- PURSUE

- REFERENCE POINT GROUP

REFERENCES

[1] G. Anastasi, M. Conti, M. Di Francesco and A. Passarella, “Energy Conservation in Wireless Sensor Network,” Elsevier, Ad Hoc Netoworks, Vol 7, Issue 6, May 2009, pp. 537-568.

[2] I. Demirkol, C.Ersoy and F.Alagöz, “MAC Protocol for Wireless Sensor Networks: A Survey”, IEEE Communications Magazine, Vol. 44, Issue 4, April 2006, pp. 115-121.

[3] I.F. Akyildiz, W. Su, Y. Sankarasubramaniam and E. Cayirci, “Wireless sensor networks: a survey”, Elsevier, Computer Network, Vol 38, Number 4, 15 March 2002, pp. 393-422.

[4] T Camp, J Boleng, V Davies – “A Survey of Mobility Models for Ad Hoc Network Research”, Wiley Interscience, Wireless Communication & Mobile Computing (WCMC): Special issue on Mobile Ad Hoc Networking: Research, Trends and Applications, . 2, Issue 5, August 2002, pp. 483-502.