Sogang University ICC Lab A Survey on Sensor Networks.

Sogang University ICC Lab Sogang University ICC Lab

A Survey on Sensor NetworksA Survey on Sensor Networks

Sogang University ICC Lab.2

Reading MaterialsReading Materials

Reference book and papers :

무선센서네트워크기술 : 저자 : 이상학 , 정태충 경희대학교출판국 ( 구 ) 경희서적센터

Related papers sensor-survey.pdf

Reference book and papers :

무선센서네트워크기술 : 저자 : 이상학 , 정태충 경희대학교출판국 ( 구 ) 경희서적센터

Related papers sensor-survey.pdf


AgendaAgenda

Introduction to Sensor Networks

Sensor Network Vs Fixed and Ad-Hoc Networks

Routing Protocols for Sensor Networks

Proposed Routing Protocol

Performance Metrics

Introduction to Sensor Networks

Sensor Network Vs Fixed and Ad-Hoc Networks

Routing Protocols for Sensor Networks

Proposed Routing Protocol

Performance Metrics


Introduction to Sensor NetworksIntroduction to Sensor Networks

What is a Sensor? A sensor is a device the produces a measurable

response to a change in physical condition such as temperature or chemical condition such as concentration

Types of Sensors - Temperature, Pressure, Humidity, Image etc

What is a Sensor? A sensor is a device the produces a measurable

response to a change in physical condition such as temperature or chemical condition such as concentration

Types of Sensors - Temperature, Pressure, Humidity, Image etc


Sensor Network ArchitectureSensor Network Architecture

Sensor Nodes

Sink

Internet/Satellite

Task Manager User


SensorsSensors

Berkeley Mote EmbedSense - Wireless Sensor and Data

Acquisition System


A sensor network is composed of a large number of sensor nodes,

- which are densely deployed either inside the phenomenon or very close to it.

A large number of low-cost, low-power, multifunctional, and small sensor nodes

Sensor node consists of sensing, data processing, and communicating components

The position of sensor nodes need not be engineered or pre-determined.

- sensor network protocols and algorithms must possess self-organizing capabilities.

A sensor network is composed of a large number of sensor nodes,

- which are densely deployed either inside the phenomenon or very close to it.

A large number of low-cost, low-power, multifunctional, and small sensor nodes

Sensor node consists of sensing, data processing, and communicating components

The position of sensor nodes need not be engineered or pre-determined.

- sensor network protocols and algorithms must possess self-organizing capabilities.

SensorsSensors


Applications of Sensor NetworksApplications of Sensor Networks

Monitoring Applications Military Security Intrusion Detection Habitat Monitoring

Environment Observation and Forecasting

Monitoring Applications Military Security Intrusion Detection Habitat Monitoring

Environment Observation and Forecasting


Sensor Vs Ad-Hoc NetworksSensor Vs Ad-Hoc Networks

Network topology is not fixed Power is an expensive resource in these

networks Nodes are connected by wireless links

The number of sensor nodes in a sensor network is much more than the nodes in an ad hoc network.

Sensor nodes are densely deployed. Sensor nodes are prone to failures. The topology of a sensor network changes very

frequently.

Network topology is not fixed Power is an expensive resource in these

networks Nodes are connected by wireless links

The number of sensor nodes in a sensor network is much more than the nodes in an ad hoc network.

Sensor nodes are densely deployed. Sensor nodes are prone to failures. The topology of a sensor network changes very

frequently.


Sensor Vs Ad-Hoc NetworksSensor Vs Ad-Hoc Networks

Large number of sensors

Addressing scheme for sensor nodes

Sensor network used for data gathering

Ad - Hoc network used for distributed computing

Data flows from multiple sources to a single

destination

Redundancy in data traffic

Large number of sensors

Addressing scheme for sensor nodes

Sensor network used for data gathering

Ad - Hoc network used for distributed computing

Data flows from multiple sources to a single

destination

Redundancy in data traffic


Sensor Vs Ad - Hoc Networks Sensor Vs Ad - Hoc Networks

Sensor nodes are prone to failure Sensor nodes mainly use broadcast communication

paradigm whereas most ad hoc networks are based on

point-to-point communications.

Sensor nodes are limited in power, computational

capacities, and memory.

Sensor nodes may not have global ID because of the

large amount of overhead and large number of sensors.

Sensor nodes are prone to failure Sensor nodes mainly use broadcast communication

paradigm whereas most ad hoc networks are based on

point-to-point communications.

Sensor nodes are limited in power, computational

capacities, and memory.

Sensor nodes may not have global ID because of the

large amount of overhead and large number of sensors.


Sensor networks communicationSensor networks communication

The sensor nodes are usually scattered in a sensor field

Each of these scattered sensor nodes has the capabilities to collect data and route data back to the sink

The sink may communicate with the task manager node via Internet or Satellite.


Hardware constraintsHardware constraints

A sensor node is made up of four basic components a sensing unit

usually composed of two subunits: sensors and analog to digital converters (ADCs).

processing unit, Manages the procedures that make the sensor node

collaborate with the other nodes to carry out the assigned sensing tasks.

A transceiver unit Connects the node to the network.

Power units (the most important unit)

A sensor node is made up of four basic components a sensing unit

usually composed of two subunits: sensors and analog to digital converters (ADCs).

processing unit, Manages the procedures that make the sensor node

collaborate with the other nodes to carry out the assigned sensing tasks.

A transceiver unit Connects the node to the network.

Power units (the most important unit)


Hardware constraintsHardware constraints


Sensor network topologySensor network topology

Pre-deployment and deployment phase Sensor nodes can be either thrown in mass or placed

one by one in the sensor field.

Post-deployment phase Sensor network topologies are prone to frequent

changes after deployment.

Re-deployment of additional nodes phase Addition of new nodes poses a need to re-organize the

network.

Pre-deployment and deployment phase Sensor nodes can be either thrown in mass or placed

one by one in the sensor field.

Post-deployment phase Sensor network topologies are prone to frequent

changes after deployment.

Re-deployment of additional nodes phase Addition of new nodes poses a need to re-organize the

network.


Power consumptionPower consumption

Only be equipped with limited power source(<0.5 Ah 1.2V)

Node lifetime strong dependent on battery lifetime

Power consumption can be divided into three domains: sensing, communication, and data processing.

Only be equipped with limited power source(<0.5 Ah 1.2V)

Node lifetime strong dependent on battery lifetime

Power consumption can be divided into three domains: sensing, communication, and data processing.


Sensor networks communicationSensor networks communication


Management PlanesManagement Planes

These management planes make sensor nodes work together in a power efficient way, route data in a mobile sensor network, and share resources between sensor nodes.

Power management plane manages how a sensor node uses its power. For example, the sensor node may turn off its receiver

after receiving a message. When the power level of the sensor node is low, the

sensor node broadcasts to its neighbors that it is low in power and cannot participate in routing messages.

These management planes make sensor nodes work together in a power efficient way, route data in a mobile sensor network, and share resources between sensor nodes.

Power management plane manages how a sensor node uses its power. For example, the sensor node may turn off its receiver

after receiving a message. When the power level of the sensor node is low, the

sensor node broadcasts to its neighbors that it is low in power and cannot participate in routing messages.


Management PlanesManagement Planes

Mobility management plane detects and registers the movement of sensor nodes So a route back to the user is always maintained the sensor nodes can keep track of who are their

neighbor sensor nodes.

Task management plane Balances and schedules the sensing tasks given to a

specific region. Not all sensor nodes in that region are required to

perform the sensing task at the same time.

Mobility management plane detects and registers the movement of sensor nodes So a route back to the user is always maintained the sensor nodes can keep track of who are their

neighbor sensor nodes.

Task management plane Balances and schedules the sensing tasks given to a

specific region. Not all sensor nodes in that region are required to

perform the sensing task at the same time.


Physical LayerPhysical Layer

Frequency selection, carrier frequency generation, signal detection, modulation, and data encryption.

915 MHz ISM band has been widely suggested for sensor networks.

Open research issues Modulation schemes Strategies to overcome signal propagation effects Hardware design

Frequency selection, carrier frequency generation, signal detection, modulation, and data encryption.

915 MHz ISM band has been widely suggested for sensor networks.

Open research issues Modulation schemes Strategies to overcome signal propagation effects Hardware design


Data link layerData link layer

The data link layer is responsible for the multiplexing of data stream, data frame detection, medium access and error control

MAC protocol for sensor network must have built-in power conservation, mobility management and failure recovery strategies

The data link layer is responsible for the multiplexing of data stream, data frame detection, medium access and error control

MAC protocol for sensor network must have built-in power conservation, mobility management and failure recovery strategies


Power saving modes of operationPower saving modes of operation

turn the transceiver off when it is not required.

Not exactly

There can be a number of such useful modes of

operation for the wireless sensor node

depending on the number of states of the micro-

processor, memory, A/D convertor and the transceiver.

turn the transceiver off when it is not required.

Not exactly

There can be a number of such useful modes of

operation for the wireless sensor node

depending on the number of states of the micro-

processor, memory, A/D convertor and the transceiver.


Network layerNetwork layer

The networking layer of sensor networks is usually designed according to the following principles: Power efficiency is always an important consideration.

Sensor networks are mostly data centric.

Data aggregation is useful only when it does not hinder the collaborative effort of the sensor nodes.

An ideal sensor network has attribute-based addressing and location awareness.

The networking layer of sensor networks is usually designed according to the following principles: Power efficiency is always an important consideration.

Sensor networks are mostly data centric.

Data aggregation is useful only when it does not hinder the collaborative effort of the sensor nodes.

An ideal sensor network has attribute-based addressing and location awareness.


Transport layerTransport layer

The transport layer is needed when the system is planned to be accessed through Internet or other external networks.

Not any scheme related to the transport layer of a sensor network has been proposed in literature.




Data-centric RoutingData-centric Routing

Interest dissemination is performed to assign the sensing tasks to the sensor nodes.

Two approaches used for interest dissemination: Sinks broadcast the interest Sensor nodes broadcast an advertisement for the

available data and wait for a request from the interested sinks.

Interest dissemination is performed to assign the sensing tasks to the sensor nodes.

Two approaches used for interest dissemination: Sinks broadcast the interest Sensor nodes broadcast an advertisement for the

available data and wait for a request from the interested sinks.


Data-centric RoutingData-centric Routing

Requires attribute-based naming Querying an attribute of the phenomenon, rather than

querying an individual node.

Ex: “the areas where the temperature is over 70°F” is a more common query than “the temperature read by a certain node”

Requires attribute-based naming Querying an attribute of the phenomenon, rather than

querying an individual node.

Ex: “the areas where the temperature is over 70°F” is a more common query than “the temperature read by a certain node”


Data aggregationData aggregation

A technique used to solve the implosion and overlap problems in data-centric routing

Data coming from multiple sensor nodes with the same attribute of phenomenon are aggregated

A technique used to solve the implosion and overlap problems in data-centric routing

Data coming from multiple sensor nodes with the same attribute of phenomenon are aggregated


Data aggregation - continueData aggregation - continue

•Sensor network is usually perceived as a reverse multicast tree.


Data aggregation - continueData aggregation - continue

can be perceived as a set of automated methods of combining the data the comes from many sensor nodes into a set of meaningful information

With this respect, data aggregation is known as data fusion

can be perceived as a set of automated methods of combining the data the comes from many sensor nodes into a set of meaningful information

With this respect, data aggregation is known as data fusion


InternetworkingInternetworking

Sink nodes can be used as a gateway to other network

Create a backbone by connecting sink nodes together and make it access other network via a gateway

Sink nodes can be used as a gateway to other network

Create a backbone by connecting sink nodes together and make it access other network via a gateway


Network layerNetwork layer

Open research issues

Improved or new protocols to address higher topology

changes and higher scalability.

Open research issues

Improved or new protocols to address higher topology

changes and higher scalability.



An approach such as TCP splitting may be needed to make sensor networks interact with other networks such as Internet.

An approach such as TCP splitting may be needed to make sensor networks interact with other networks such as Internet.

TCP/UDP

?



Open research issues Hardware constraints such as limited power and

memory. Each sensor node cannot store large amounts of data like a server in the internet.

Acknowledgments are too costly.

may be needed where UDP-type protocols are used in the sensor network and TCP/UDP protocols in the internet or satellite network.

Open research issues Hardware constraints such as limited power and

memory. Each sensor node cannot store large amounts of data like a server in the internet.

Acknowledgments are too costly.

may be needed where UDP-type protocols are used in the sensor network and TCP/UDP protocols in the internet or satellite network.


Application layerApplication layer

Potential application layer protocols for sensor networks remains a largely unexplored region.

Potential application layer protocols for sensor networks remains a largely unexplored region.


Routing issuesRouting issues

Node deployment Manual deployment

Sensors are manually deployed Data is routed through predetermined path

Random deployment Optimal clustering is necessary to allow connectivity &

energy-efficiency Multi-hop routing

Node deployment Manual deployment

Sensors are manually deployed Data is routed through predetermined path

Random deployment Optimal clustering is necessary to allow connectivity &

energy-efficiency Multi-hop routing



Data routing methods Application-specific Time-driven: Periodic monitoring Event-driven: Respond to sudden changes Query-driven: Respond to queries Hybrid

Data routing methods Application-specific Time-driven: Periodic monitoring Event-driven: Respond to sudden changes Query-driven: Respond to queries Hybrid



Node/link heterogeneity Homogeneous sensors Heterogeneous nodes with different roles & capabilities

Diverse modalities If cluster heads may have more energy & computational

capability, they take care of transmissions to the base station (BS)

Node/link heterogeneity Homogeneous sensors Heterogeneous nodes with different roles & capabilities

Diverse modalities If cluster heads may have more energy & computational

capability, they take care of transmissions to the base station (BS)



Fault tolerance Some sensors may fail due to lack of power, physical

damage, or environmental interference Adjust transmission power, change sensing rate,

reroute packets through regions with more power

Fault tolerance Some sensors may fail due to lack of power, physical

damage, or environmental interference Adjust transmission power, change sensing rate,

reroute packets through regions with more power



Network dynamics Mobile nodes Mobile events, e.g., target tracking If WSN is to sense a fixed event, networks can work in

a reactive manner A lot of applications require periodic reporting

Network dynamics Mobile nodes Mobile events, e.g., target tracking If WSN is to sense a fixed event, networks can work in

a reactive manner A lot of applications require periodic reporting



Transmission media Wireless channel Limited bandwidth: 1 – 100Kbps MAC

Contention-free, e.g., TDMA or CDMA Contention-based, e.g., CSMA, MACA, or 802.11

Transmission media Wireless channel Limited bandwidth: 1 – 100Kbps MAC

Contention-free, e.g., TDMA or CDMA Contention-based, e.g., CSMA, MACA, or 802.11



Connectivity High density high connectivity Some sensors may die after consuming their battery

power Connectivity depends on possibly random deployment

Connectivity High density high connectivity Some sensors may die after consuming their battery

power Connectivity depends on possibly random deployment



Coverage An individual sensor’s view is limited Area coverage is an important design factor

Data aggregation Quality of Service

Bounded delay Energy efficiency for longer network lifetime

Coverage An individual sensor’s view is limited Area coverage is an important design factor

Data aggregation Quality of Service

Bounded delay Energy efficiency for longer network lifetime


Classification of Routing ProtocolsClassification of Routing Protocols

Data-centric protocols naming 과 query-based 로 중복된 전송제거

Hierarchical protocols data 를 집적하고 축소 하기 위해 클러스터링을 이용

Location-based protocols 전체 네트워크 보다는 요구된지역에 data 를 전달하기

위하여 위치 정보를 이용

Data-centric protocols naming 과 query-based 로 중복된 전송제거

Hierarchical protocols data 를 집적하고 축소 하기 위해 클러스터링을 이용

Location-based protocols 전체 네트워크 보다는 요구된지역에 data 를 전달하기

위하여 위치 정보를 이용


Data Centric RoutingData Centric Routing

Address Centric Routing Finding short routes between pairs of addressable end

nodes

Data Centric Routing Perform in-network consolidation of redundant data

while routing from source to the sink

Address Centric Routing Finding short routes between pairs of addressable end

nodes

Data Centric Routing Perform in-network consolidation of redundant data

while routing from source to the sink


Flooding Each node receiving a data or management packet repeats it by

broadcasting Does not require costly topology maintenance and complex route

discovery algorithms. Implosion: a situation where duplicated messages are sent to the

same node. Overlap: If two nodes share the same obserying region, both of

them may sense the same stimuli at the same time. As a result, neighbor nodes receive duplicated messages.

Resource blindness: flooding does not take into account the available energy resources.

Flooding Each node receiving a data or management packet repeats it by

broadcasting Does not require costly topology maintenance and complex route

discovery algorithms. Implosion: a situation where duplicated messages are sent to the

same node. Overlap: If two nodes share the same obserying region, both of

them may sense the same stimuli at the same time. As a result, neighbor nodes receive duplicated messages.

Resource blindness: flooding does not take into account the available energy resources.

FloodingFlooding


Gossiping

A derivation of flooding

Nodes send the incoming packets to a randomly selected

neighbor.

Avoids the implosion problem

It takes a long time to propagate the message to all sensor

nodes.

Gossiping

A derivation of flooding

Nodes send the incoming packets to a randomly selected

neighbor.

Avoids the implosion problem

It takes a long time to propagate the message to all sensor

nodes.

GossipingGossiping


Sensor protocols for information via negotiation (SPIN): Designed to address the deficiencies of classic flooding

by negotiation and resource adaptation.

sending data that describe the sensor data instead of sending the whole data

As a result, the sensor nodes in the entire sensor network that are interested in the data will get a copy. Note that SPIN is based on data-centric routing.

Sensor protocols for information via negotiation (SPIN): Designed to address the deficiencies of classic flooding

by negotiation and resource adaptation.

sending data that describe the sensor data instead of sending the whole data

As a result, the sensor nodes in the entire sensor network that are interested in the data will get a copy. Note that SPIN is based on data-centric routing.

The SPIN protocolThe SPIN protocol


Sequential assignment routing (SAR) A set of algorithms, which perform organization, management

and mobility management operations in sensor networks

Creates multiple trees where the root of each tree is one hop neighbor from the sink

Most nodes belong to multiple trees, allows a sensor node to choose a tree to relay its information back to the sink.

select a tree for data to be routed back to the sink according to the energy resources and additive QoS metric

Sequential assignment routing (SAR) A set of algorithms, which perform organization, management

and mobility management operations in sensor networks

Creates multiple trees where the root of each tree is one hop neighbor from the sink

Most nodes belong to multiple trees, allows a sensor node to choose a tree to relay its information back to the sink.

select a tree for data to be routed back to the sink according to the energy resources and additive QoS metric

sink

SAR(Sequential assignment routing)SAR(Sequential assignment routing)


Hierarchical ProtocolsHierarchical Protocols

When sensor density increases single tier networks cause Gateway overloading Increased latency Large energy consumption Clustered Network allow coverage of large area of

interest and additional load without degrading the performance

When sensor density increases single tier networks cause Gateway overloading Increased latency Large energy consumption Clustered Network allow coverage of large area of

interest and additional load without degrading the performance


Hierarchical ProtocolsHierarchical Protocols

Hierarchical routing Uses Multi - hop communication within a cluster

Performs data aggregation and fusion on data to reduce number of transmitted messages to the sink

Maintain the energy reserves of nodes efficiently

Example - LEACH, PEGASIS

Hierarchical routing Uses Multi - hop communication within a cluster

Performs data aggregation and fusion on data to reduce number of transmitted messages to the sink

Maintain the energy reserves of nodes efficiently

Example - LEACH, PEGASIS


Low-energy adaptive clustering hierarchy (LEACH) Randomly select sensor nodes as cluster-heads, so the high

energy dissipation in communicating with the base station is spread to all sensor nodes in the sensor network.

Set-up phase each sensor node chooses a random number between 0 and 1 If this random number is less than the threshold T(n), the

sensor node is a cluster-head.

Low-energy adaptive clustering hierarchy (LEACH) Randomly select sensor nodes as cluster-heads, so the high

energy dissipation in communicating with the base station is spread to all sensor nodes in the sensor network.

Set-up phase each sensor node chooses a random number between 0 and 1 If this random number is less than the threshold T(n), the

sensor node is a cluster-head.P,the desired percentage to become a cluster-head;

r,the current round

G , the set of nodes that have not being selected as a cluster-head in the last 1/P rounds.

LEACHLEACH


Set-up phase (cont’d) The cluster-heads advertise to all sensor nodes in the

network

The sensor nodes inform the appropriate cluster-heads that they will be a member of the cluster. (base on signal strength)

Afterwards, the cluster-heads assign the time on which the sensor nodes can send data to the cluster-heads based on a

TDMA approach.

Set-up phase (cont’d) The cluster-heads advertise to all sensor nodes in the

network

The sensor nodes inform the appropriate cluster-heads that they will be a member of the cluster. (base on signal strength)

Afterwards, the cluster-heads assign the time on which the sensor nodes can send data to the cluster-heads based on a

TDMA approach.

LEACHLEACH


steady phase (cont’d) the sensor nodes can begin sensing and transmitting data to

the cluster-heads. The cluster-heads also aggregate data from the nodes in

their cluster before sending these data to the base station.

After a certain period of time spent on the steady phase, the network goes into the set-up phase again and enters into another round of selecting the cluster-heads.

steady phase (cont’d) the sensor nodes can begin sensing and transmitting data to

the cluster-heads. The cluster-heads also aggregate data from the nodes in

their cluster before sending these data to the base station.

After a certain period of time spent on the steady phase, the network goes into the set-up phase again and enters into another round of selecting the cluster-heads.

LEACHLEACH


Directed DiffusionDirected Diffusion

the sink sends out interest to sensors

As the interest is propagated throughout the sensor network, the gradients from the source back to the sink are set up

When the source has data for the interest, the source sends the data along the interest’s gradient path


Location Based ProtocolsLocation Based Protocols

Location information can be used to Find shortest path to the sink Form a virtual grid and keep only few nodes active at a

time

Example GAF GEAR

Location information can be used to Find shortest path to the sink Form a virtual grid and keep only few nodes active at a

time

Example GAF GEAR


Determining LocationDetermining Location

Location of a node can be determined using Global Positioning System Ultrasonic Systems Beacons

Location based protocols assume that each node knows its location in the network

Location of a node can be determined using Global Positioning System Ultrasonic Systems Beacons

Location based protocols assume that each node knows its location in the network


GAF(Geographic Adaptive Fidelity)GAF(Geographic Adaptive Fidelity)

Forms a virtual grid of the covered area

Each node associates itself with a point in the grid based on its location

Nodes associated with same point in grid are considered equivalent

Some nodes in an area are kept sleeping to conserve energy

Nodes change state from sleeping to active for load balancing

Forms a virtual grid of the covered area

Each node associates itself with a point in the grid based on its location

Nodes associated with same point in grid are considered equivalent

Some nodes in an area are kept sleeping to conserve energy

Nodes change state from sleeping to active for load balancing


GAFGAF

A node remains active for time Ta

Ta of a node in the grid is broadcasted to other equivalent nodes

The sleeping time of a node is adjusted depending on Ta

In the discovery state each node broadcasts discovery messages periodically (Td)

A node remains active for time Ta

Ta of a node in the grid is broadcasted to other equivalent nodes

The sleeping time of a node is adjusted depending on Ta

In the discovery state each node broadcasts discovery messages periodically (Td)


Sleeping

Discovery Active

After Ts

After Ts

After Td

State Transition for GAF State Transition for GAF


Routing in GAFRouting in GAF

Base Station


GAFGAF

Not very scalable. As the network size increases distance to the base station increases

Only the active nodes sense and report data. Hence data accuracy is not very high.

Not very scalable. As the network size increases distance to the base station increases

Only the active nodes sense and report data. Hence data accuracy is not very high.


GEAR (Geographically and Energy Aware

Routing)GEAR (Geographically and Energy Aware

Routing) Queries

Contain location information Disseminated to only the specified region of the

network

Neighbors are selected probabilistically to forward the query to the target location

Query is flooded only in the target region

Queries Contain location information Disseminated to only the specified region of the

network

Neighbors are selected probabilistically to forward the query to the target location

Query is flooded only in the target region


GEAR GEAR

Each node maintains a neighbor table Energy levels and locations of each neighbor Cost to transmit to each neighbor

Packet is forwarded to neighbor with smallest cost

Each node maintains a neighbor table Energy levels and locations of each neighbor Cost to transmit to each neighbor

Packet is forwarded to neighbor with smallest cost


Base Station

Region of Interest

GEAR GEAR


GEARGEAR

Not Scalable

All nodes are active even though only a part of the network is queried

Not Scalable

All nodes are active even though only a part of the network is queried


Performance MetricsPerformance Metrics

Average Energy Consumption

Impact of localization errors

Energy and time expended for cluster formation

Network lifetime

Average Energy Consumption

Impact of localization errors

Energy and time expended for cluster formation

Network lifetime


ConclusionConclusion

In the future, this wide range of application areas will make sensor networks an integral part of our lives.

However, realization of sensor networks needs to satisfy the constraints introduced by factors such as fault tolerance, scalability, hardware, topology change, environment and power consumption.

Many researchers are currently engaged in developing the technologies needed for different layers of the sensor networks protocol stack

In the future, this wide range of application areas will make sensor networks an integral part of our lives.

However, realization of sensor networks needs to satisfy the constraints introduced by factors such as fault tolerance, scalability, hardware, topology change, environment and power consumption.

Many researchers are currently engaged in developing the technologies needed for different layers of the sensor networks protocol stack

Sogang University ICC Lab A Survey on Sensor Networks.

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Transcript of Sogang University ICC Lab A Survey on Sensor Networks.