The Military Applications- The military application of sensor nodes include battle field surveillances and monitoring, guiding system of intelligent missile and detection of attack by weapons of mass destruction.
The Medical Applications sensor are extremely useful in patient diagnosis and monitoring . Patient can wear small sensor devices that monitor the physiological data like heart rate blood pressure. Environmental Monitoring – This include traffic ,habitat , wild life Target tracking Industrial Application- it include industrial sensing and diagnostic Infrastructure and protection application- it is use for power grid monitoring and water distribution monitoring.
Wireless Sensor network is built up of several nodes interconnected with each other. They may vary in size from a shoebox to a size of tiny grain. These small size sensor nodes are equipped with embedded microprocessor and radio transceiver and capable of sensing, communication and data processing. The sensor Network consists of base stations and many wireless sensor nodes.
Structure of Sensor Node- Sensor Node is composed of Sensing unit, a processing unit, Communication unit and power unit. Sensing unit basically consists of Analog to Digital convertor. These sensor nodes have the capability of sensing, computation and wireless communication. Sensor nodes observe the physical phenomenon and generate analog signal based upon that. Processing unit consists of either a microcontroller or microprocessor that provides intelligence control to sensor nodes. Communication unit consists of short-range radio for data transmission purpose.
This approach avoids longhop relaying and reduces energy consumption at sensor nodes near the base station, prolonging the network lifetime.
Notes- Routing is fundamental for wireless sensor network because there is no infrastructure that manages information between nodes so each network node act as router . It is difficult for ensure best suitable routing protocol for such type of network .To specify a significant protocol we followed some strategy. Routing protocol has two class flat and hierarchical. Flat routing is further classified in two category Proactive and reactive . Flat-based All nodes are typically assigned equal roles or functionality.
Hierarchical-based Nodes will play different roles in the network.
Proactive Routing Protocols (Table-driven) Nodes exchange routing information periodically in order to maintain consistent and accurate information. To transmit data to a destination, path can be computed rapidly based on the updated information available in the routing table. The disadvantage of using a proactive protocol is high overhead needed to dynamic topology that might require a large number of routing updates. Each node maintains a routing table, with an entry for each possible destination address, next hop on the shortest path to that destination, shortest known distance to this destination, and a destination sequence number that is created by the destination itself.
Reactive Routing Protocols (On-demand) Route discovery mechanism is initiated only when a node does not know the path to a destination it wants to communicate with. In case of mobile ad hoc network, reactive routing protocols have been demonstrated to perform better with significantly lower changes that may occur in node connectivity, and yet are able to reduce/eliminate routing overhead in periods or areas of the network in which changes are less frequent. A reactive routing has two main operations- Route discovery Route maintenance. Various reactive protocols have been proposed such as Ad Hoc On-demand vector (AODV), Dynamic source routing (DSR), Temporary Ordered Routing Algorithm (TORA), etc.
Sequence number indicate route age.
Sensor Node Deployment-The sensor nodes have predefined data collection region. This data collection region is represented with topography coordinates X and Y. In our project, terrain range (X and Y coordinates) is 1070, 1070. Clustering- These sensor nodes (53) form a group together known as a cluster. Every cluster has a cluster head (CH). Each remaining node in a cluster except the ‘Cluster Head’ is called a ‘Cluster Candidate’. Cluster Size- Position of base station with respect to cluster head is a key parameter to decide cluster size for example if cluster head is far away from the base station the size of cluster reduces and when it come closer to the base station the cluster size increases. Clusters with their cluster heads near the mobile sink trajectory are small because of the heavy relay traffic coming from other parts of the network. This way, the cluster heads do not have to perform inter-cluster processing and communication tasks. Rendezvous node/polling point selection- The rendezvous nodes guarantee connectivity of ‘Sensor Island’ with ‘Mobile Sink’. The selection of these nodes has a huge impact on network lifetime. After that, Rendezvous node is to be selected which is the “back up” node. After collecting the data from ‘cluster candidates’, the ‘Cluster Head’ sends the data to rendezvous node. ‘Mobile sink’ is a device, which is similar to vehicle. It moves to the ‘Rendezvous node’s’ coverage area and collects the data from all rendezvous nodes.
Project Implementation has two types of models- Mobility generation model – It is used to study the effect of mobility of nodes on overall performance of the network. Traffic generation model- it is used to study the effect of traffic load on the the network .
Layered Architecture of NS2 has shown below it has three layers last layer includes Implementation part that require C++ programing. In the middle layer, Network Scheduler and other components are implemented with C++ programing language. Tcl /OTcl is a scripting Interpreter that help to setup and run simulation. Upper layer contain Simulation scenario.
An event in NS is a packet ID that is unique for a packet with scheduled time and the pointer to an object that handles even . Event scheduler keep track of simulation time and fires all event in the event queue.
Graduate Project Presentation
Presented By – Braj Raj Singh
Telecommunication Engineering Technology
Efficient Data Aggregation from polling points
in Wireless Sensor Network
A number of approaches exploiting sink mobility for data collection in wireless sensor
networks have been proposed in recent years.
• In single hop communication, we can minimize energy consumption, however, at the
expense of high data delivery delay.
• In the second solution, this delay is low but the energy consumption due to multi hop
communication is rather high.
Our proposed protocol aims at minimizing the overall network overhead and energy
expenditure associated with the multi hop data retrieval process while also ensuring
balanced energy consumption among sensor nodes and prolonged network lifetime. This is
achieved through building cluster structures consisted of member nodes that route their
measured data to their assigned cluster head (CH).
Clustering has proven to be an effective approach for organizing the network in the above
context. Besides achieving energy efficiency, clustering also reduces channel contention and
packet collisions, resulting in improved network throughput under high load.
Wireless Sensor Network
A Collection of Spatially Distributed Organized autonomous sensor nodes that
collects data from its surrounding.
The Wireless sensor network is a combination of wireless sensing and data
networking that consists of protocols and algorithms with self-organizing
capabilities and can be used in safety-critical or highly reliable applications
• Scalability and Reliability
• Flexible Topology Changes
• No wired infrastructure
• Potential multi-hop routes
• Ability to withstand in harsh environmental conditional
Applications of WSN-
Topology of Wireless Sensor Network
• Point to point (Peer to Peer) topology- In this type of network
topology nodes are involved in direct node-to-node communication
without going through centralized communication hub. Each peer is
able to work as either client or server.
• Star topology- In star topology, each node must communicate
through a centralized connected hub. Information cannot be directly
routed through node-to-node .The centralized hub works as server
and connecting nodes works as clients.
• Tree based topology- In a tree based topology, the centralized node
functions as root node. A root node has a central hub that is one step
down in hierarchy. This lower level then forms a star based network,
which is why a tree network is also called hybrid network.
• Meshed Network topology- Mesh networks have a self-healing
property because it allows data to hop from node to node. This type
of network is very complex as compared to other topologies and is
more cost effective.
Architecture of Wireless Sensor Network
Wireless sensor network composed of two distinct layers
• Sensor and Networking layers
• Distributed Service layer
Key component of Sensor Network-
1. Sensor Nodes (SN)
2. Cluster Head (CH)
3. Mobile Collector (MS)
4. Rendezvous Nodes /Polling Points
5. Base Station
Sensing Unit (A/D convertor)
Power supply (battery)
Communication Unit (radio trans-receiver)
2. Cluster Head ( CH)
In wireless sensor network, small group of sensor node formed a cluster and each cluster has
a coordinator referred Cluster head (CH). Cluster head selection has impact on network
lifetime. Cluster Head should be reachable in a single hop from their cluster members.
Primary function of Cluster head –
Aggregate data from respective sensor
node and transferred to remote
Localization of network traffic.
CH implement network management
strategy to enhance network operation
and prolong the battery life.
Reduce the rate of energy
consumption by schedule activity
activities in the cluster so sensor node
can switch to low power sleep mode
3. Mobile collector
Data Collector (Sink) can be classified in two category-
Static Collector- Network sink nodes are on fixed
position; either close or inside the sensing region that
makes network simpler to control.
Mobile Collector-The Mobile Collector (MC) moving
through the network deployment region can collect
data from the static sensor nodes over a single hop
radio link when approaching within the radio range of
the sensor nodes or with limited hop transfers if the
sensor nodes are located further.
Mobility pattern of Data collector-
b) Predictable (their movement pattern is known before hand)
c) Controlled (their movement is actively controlled in real time)
4. Polling Points /Rendezvous Nodes-
• Polling points guarantee connectivity of sensor clusters with Mobile collector. Their
selection largely determines network lifetime.
• Polling points are selected among candidate Sensor node typically located in the
periphery of the sensor island and lie within the range of mobile collector.
• Suitable polling points are those that remain within the Mobile collector range for
• relatively long time, in relatively short distance from the sink's trajectory and have
sufficient energy supplies.
5. Base Station
The base stations are one or more components of the WSN with more computational
energy and communication resources. They act as a gateway between sensor nodes
and the end user as they typically forward data from the wireless sensor network on
to a server.
Clustering is a process of logical grouping of similar sensors to achieve load balancing and
network scalability . Clustering is an effective approach for organizing the network that
reduces channel contention, packet collision and improved network throughput under high
Data Aggrega on
Cluster Head Elec on
Cluster Forma on
Cluster forma on and Data Collec on approach by Mobile Sink from Sensor Nodes
Support Network Scalability
Decrease energy consumption through data aggregation
Limits data transmission (load balancing)
Facilitate the reusability of the resources
Conserve communication bandwidth
Cluster Head and gateway nodes can form a virtual backbone for inter-
Cluster structure gives the impression of a smaller and more stable
Improve network lifetime
Reduce network traffic and the contention for the channel
Data aggregation and updates take place in CHs
Clustering support network scalability and reduces energy consumption through efficient
data aggregation. It can localize the route setup with in the cluster and thus reduce the size of
routing table that help to stabilize network topology.
Cluster communication can be classified as-
Base Sta on
Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding without clustering –Single hop Mechanism
Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding without clustering –Mul -hop Mechanism
Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding with clustering –Single hop Mechanism
Cluster Forma on
Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding with clustering –Mul -hop Mechanism
Cluster Forma on
Routing has two main function- Route Discovery and Packet forwarding .
The major requirements of a routing protocol-
• Minimum route acquisition delay
• Quick route reconfiguration in the case of path breaks.
• Loop-free routing
• Distributed routing protocol
• Low control over-head
• Scalability with network size
• QoS support as demanded by the application
• Support of time-sensitive traffic and
• Security and privacy
Types of Routing -
Rou ng Protocol
Proac ve Reac ve
Proactive Vs. Reactive-
Proactive (Table Driven) Reactive (On- Demand)
Route from each node to every other node in
Routes from Source to Destination only
Routes are ready to use instantaneously Routes constructed when needed, higher
connection setup delay
Periodic route-update packets Route update when necessary
Changes to network topology immediately
Changes to network topology not propagated
Large routing tables Small or No routing tables
AODV Routing Protocol
Reactive or on Demand
Uses bi-directional links
Route discovery cycle used for route based on
Sequence numbers used for loop prevention and as route
Provides unicast and multicast communication
Maintain Active routes.
Whenever routes are not used -> get expired->Discarded
– Reduces stale routes
– Reduces need for route maintenance
AODV Routing Table
In AODV each node maintain a routing table this routing table contains information about
reaching destination nodes .The routing table field includes- Destination IP address,
destination sequence number, valid destination sequence number flag, Network interface,
hop count, next hop, precursor list and life time which is normally route expiration or
AODV Route Discovery Mechanism
In AODV protocol when a node willing to send a packet to some Destination .It checks its
routing table to determine if it has a current route to the destination-
• If Yes, forwards the packet to next hop node
• If No, it initiates a route discovery process
❒ Route discovery process begins with the creation of a Route Request (RREQ) packet ->
RREQ- route request-
RREQ contain most recent sequence number of the destination. RREQ is broadcasted when
a node needs to discover a route to its destination. As this message propagate through a
network intermediate nodes use it to update their routing table.
❒ Packet also contains broadcast ID number, Broadcast ID gets incremented each time a
source node uses RREQ
• Broadcast ID and source IP address form a unique identifier for the RREQ
❒ Broadcasting is done via Flooding
Propagation of Route Reply (RREP) message-
When a RREQ reaches a destination node the destination route is made available by Unicast a
RREP back to the source route. A node generate RREP if it has an active route to destination.
As RREP propagate back to the source node, intermediate nodes update their routing table.
Route Error Message ( RERR)-
RERR is initiated by the node upstream (closer to the source) of the break
• Its propagated to all the affected destinations
• RERR lists all the nodes affected by the link failure -> Nodes that were using the link to
route messages (precursor nodes)
• When a node receives an RERR, it marks its route to the destination as invalid -> Setting
distance to the destination as infinity in the route table
❒ When a source node receives an RRER, it can reinitiate the route discovery
1. Link between C and D breaks
2. Node C invalidates route to D in
3. Node C creates Route Error
• Lists all destinations that are now
• Sends to upstream neighbors
Route Maintenance Mechanism-
Node A receives RERR
• Checks whether C is its next hop on
route to D
• Deletes route to D (makes distance -
• Forwards RERR to S
Node S receives RERR
• Checks whether A is its next hop
on route to D
• Deletes route to D
• Rediscovers route if still needed
Importance of Sequence Number -
Sequence numbers used for route freshness and loop prevention
To prevent formation of loops
• A had a route to D initially
• Assume that A does not know about failure of
because RERR sent by C is lost
Now C performs a route discovery for D. Node A
receives the RREQ (say, via path C-E-A)
• Node A will reply since A knows a route to D
via node B
• Results in a loop (for instance, C-E-A-B-C )
Because of usage of sequence number, A
will not use the route A-B-C, because the
sequence numbers will be lower than what A
receives from A
DSDV Routing Protocol
The DSDV routing protocol is an enhanced version of the distributed Bellman-Ford
algorithm where each node maintain a table that contain the shortest distance and
the first node on the shortest path to every other node in the network.
Routing table updates are periodically transmitted.
To minimize the routing updates, variable sized update packets are used depending
on the number of topological changes.
Each entry in the table is marked by a sequence number which helps to distinguish
stale routes from new ones, and thereby avoiding loops.
When a route update with higher sequence number is received, the old route is
replaced. And when there are two different routes exist with same sequence number
the route with better matrix is used.
DSDV adds two things to distance vector routing –
a) Sequence number that avoid loops
b) Damping- hold advertisement for changes of short duration
Each node periodically transmits update that includes own sequence number and
routing table update.
Node also send routing table update for important link changes.
When two to a destination received from two different neighbors –
a) Chose the one with greatest destination sequence number
b) If equal chose the smaller metric (hop count)
DSDV Table structure
Sequence Number- sequence number originated from destination number and it
ensures loop freeness.
Install time –when entry was made (Used to delete stale entry from the table)
Stable Data -Pointer to a table holding information on how stable a route is. Used
to damp fluctuations in network.
The main advantage of DSDV protocol is this is loop free through destination
sequence number and there is no latency caused by route discovery. But it has
overhead issue because most routing information is never used.
Destination Next Metric Seq. Nr Install Time Stable Data
A A 0 A-550 001000 Ptr_A
B B 1 B-102 001200 Ptr_B
C B 3 C-588 001200 Ptr_C
D B 4 D-312 001200 Ptr_D
Proposed System-Mobi Cluster
Base Sta on 1 Base Sta on 2
Mobile Collector 1 Mobile Collector 2
Polling Point/Rendezvous Node
• Mobi-cluster protocol helps to ensures delivery of data even through multi-hop transfers from source
sensor nodes located far from the mobile sink trajectories.
• Building hierarchical cluster structures comprising neighbor sensor node to increase the performance
of intra-cluster data filtering and minimize the data relaying overhead.
• Emphasis is given on selecting the appropriate polling points among Sensor nodes located in the
periphery of the sensor islands
(so that they remain within the range of MSs for sufficient time and they buffer data from balanced-
sized groups of source SNs)
Five stages of Mobi-Cluster Protocol-
1.Cluster Head Selection
2. Polling point selection
3. Cluster Head attachment to Polling points
4. Data Aggregation and forwarding to Polling points
5. Communication between Poling point and Mobile collector(data)
2 3 4 51
Ini al 3 Phase are-Set up Phase Last two phases are steady phase
In Setup phase mobile sink complete a single trip
while broadcas ng beacon message periodically .
Sensor in the Network used this ‘Beacon’ message to
determine number of important parameter for
protocol opera on
In steady Phase sensor data rou nely gathered
and sent to mobile sink. This phase includes
reselec on of Rendezvous nodes and local re-
clustering . Local Re-Clustering performed when
some important nodes suffer from energy
exhaus on condi on
Implementation is the stage of the project when the theoretical
design is turned out into a working system. Thus it can be
considered to be the most critical stage in achieving a successful
new system and in giving the user, confidence that the new
system will work and be effective.
The implementation stage involves careful planning,
investigation of the existing system and it’s constraints on
implementation, designing of methods to achieve changeover
and evaluation of changeover methods. The process of putting
the developed system in actual use is called system
Implementation is the final phase. It involves user training,
system testing and successful running of developed system.
It is a discrete event simulator that is object oriented
C++ event scheduler is implemented in the back end
OTCL is implemented in front end
NS-2 can be used on UNIX as well Windows operating system(
Layered Architecture of NS-2
Scenario 1 2
Set ns_ [new Simulator]
Set node_(0) [$ns_node]
Set node_(1) [$ns_node]
Class MobileNode :public Node
Friend class posi on handler;
implemented by c++
Layered Architecture of NS2 ( Network Simulator)
Future Approach- Enhance Data Aggregation strategy (Using Remote Agent)
COMPARISON BASED ANALYSIS5
PDR ( Packet Delivery Ratio)-
PDR= No of packet received by destination / No of packet sent by content based source
Total Energy Consumption
Total Energy Consumption (Kbps)
Throughput calculation provides information about successful data delivery from a
receiver to a sender over communication stream; this communication steam can be either
logical or physical link .The data transmission calculated in bits per second or kilobits per
second. For efficient network a routing protocol with higher throughput is desirable
Rendezvous Planning In Wireless Sensor Networks With Mobile Elements
Guoliang Xing, Member, IEEE, Tian Wang, Student Member, IEEE, Zhihui Xie, and
Weijia Jia, Senior Member, IEEE
Sencar: An Energy-Efficient Data Gathering Mechanism For Large-Scale Multi-Hop Sensor Networks
Ming Ma, Student Member, IEEE, and Yuanyuan Yang, Senior Member, IEEE
Energy-Efficient Mobile Data Collection In Wireless Sensor Networks With Delay Reduction Using Wireless
Arun K. Kumar and Krishna M. Sivalingam Dept. of Computer Science and Engineering,
Mobile Element Scheduling with Dynamic Deadlines
Arun A. Somasundara, Aditya Ramamoorthy, Member, IEEE, and
Mani B. Srivastava, Senior Member, IEEE
Adaptive Sink Mobility in Event-Driven Densely Deployed Wireless Sensor Networks
Zoltán Vincze1, Dorottya Vass1, Rolland Vida1, Attila Vidács1 and András Telcs2
Optimal Speed Control of Mobile Node for Data Collection in Sensor Networks
Ryo Sugihara, Student Member, IEEE, and Rajesh K. Gupta, Fellow, IEEE
Joint Mobility and Routing for Lifetime Elongation in Wireless Sensor Networks
Jun Luo Jean-Pierre Hubaux
Clustering in Wireless Sensor Networks
Basilis Mamalis, Damianos Gavalas, Charalampos Konstantopoulos, and Grammati Pantziou
Prolonging the Lifetime of Wireless Sensor Networks via Unequal Clustering
Stanislava Soro and Wendi B. Heinzelman