Transcript Wireless sensor network

LOCATION BASED ROUTING
IN AD HOC NETWORK
The 11th Meeting
ROUTING IN AD HOC NETWORK
 Routing protocols in communication networks obtain route
information between pairs of nodes wishing to communicate.
 Proactive protocols: the protocol maintains routing tables at each
node that is updated as changes in the network topology are
detected.
 Reactive protocols: routes are constructed on demand. No global
routing table is maintained.
– Ad hoc on demand distance vector routing (AODV)
– Dynamic source routing (DSR)
 However, both depend on flooding for route discovery.
GEOGRAPHICAL ROUTING
 Geographical routing uses a node’s location to discover path to
that route.
 Assumptions:
– Nodes know their geographical location
– Nodes know their 1-hop neighbors
– Routing destinations are specified geographically (a location, or
a geographical region)
– The connectivity graph is modeled as a unit disk graph.
unit disk graph is the intersection graph of a family of unit disks in the Euclidean plane
GEOGRAPHICAL ROUTING (2)
 The information that the source node has
– The location of the destination node;
– The location of itself and its 1-hop neighbors.
 Geographical forwarding: send the packet to the 1-hop neighbor
that makes most progress towards the destination.
– No flooding is involved.
 Many ways to measure “progress”.
– The one closest to the destination in Euclidean distance.
– The one with smallest angle towards the destination: “compass
routing”. Etc.
GEOGRAPHICAL ROUTING (3)
 Geographic routing requires that each node can determine its own
location and that the source is aware of the location of the
destination.
 With this information a message can be routed to the destination
without knowledge of the network topology or a prior route
discovery.
 There are various approaches, such as single-path, multi-path
and flooding-based strategies.
 Most single-path strategies rely on two techniques: greedy
forwarding and face routing.
GREEDY FORWARDING
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Greedy forwarding tries to bring the message closer to the destination in each step
using only local information.
Each node forwards the message to the neighbor that is most suitable from a local
point of view
The most suitable neighbor can be the one who minimizes the distance to the
destination in each step (Greedy)
Greedy forwarding can lead into a dead end, where there is no neighbor closer to the
destination
Face routing helps to recover from that situation and find a path to another node,
where greedy forwarding can be resumed.
A recovery strategy such as face routing is necessary to assure that a message can be
delivered to the destination. The combination of greedy forwarding and face routing
was first proposed in 1999 under the name GFG (Greedy-Face-Greedy).
GREEDY FORWARDING (2)
GREEDY FORWARDING (3)
HOW TO GET AROUND LOCAL MINIMA?
Use a planar subgraph: a straight line graph with no crossing edges. It
subdivides the plane (bidang/sector) into connected regions called faces.
FACE ROUTING
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Keep left hand on the wall, walk until hit the straight line connecting source to
destination.
Then switch to the next face.
FACE ROUTING (2)
FACE ROUTING (3)
FACE ROUTING (4)
FACE ROUTING (5)
FACE ROUTING (6)
FACE ROUTING (7)
FACE ROUTING PROPERTIES
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All necessary information is stored in the message
– Source and destination positions
– The node when it enters the perimeter mode.
– The first edge on the current face.
Completely local:
– Knowledge about direct neighbors’ positions is sufficient
– Faces are implicit. Only local neighbor ordering around each node is needed
WHAT IF THE DESTINATION IS DISCONNECTED?
 The perimeter routing
will get back to where it
enters the perimeter
mode.
 Failed – no way to the
destination.
 Guaranteed delivery of a
message if there is a
path.
WIRELESS SENSOR NETWORK
WIRELESS SENSOR NETWORK (1)
“A wireless sensor network (WSN) is a wireless network
consisting of spatially distributed autonomous devices
using sensors to cooperatively monitor physical or
environmental conditions, such as temperature, sound,
vibration, pressure, motion or pollutants, at different
locations.”
WIRELESS SENSOR NETWORK (2)
 A network that connects to devices such as sensor nodes, routers and
sink nodes.
 The devices are connected in an ad-hoc and support to multi-hop
communications.
 The term ad-hoc refers to the ability of the device to communicate with
each other directly without the need for network infrastructure such as
a router or access point.
 While multi-hop is a term that refers to some communication among
devices that involve the intermediate (perantara), multi-hop involves
devices such a router to forward packets from one node to another
node in the network.
WIRELESS SENSOR NETWORK (3)
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Wireless Sensor Network (WSN) is a new class of computer
network consisting of several sensor nodes that communicate and
work together to collect data from the surrounding environment,
such as temperature, air pressure, humidity and other
environmental parameters.
WIRELESS SENSOR NETWORK (4)
 A sensor node has two components, namely mote and sensor.
 Sensors are always attached to the mote.
 Mote is responsible for the storage, computing and
communications.
 Sensors are responsible for sensing physical phenomena such as
temperature, light, sound, vibration, and so forth.
 Sensor nodes collect data and can perform processing in the
network on data collected at the intermediate node before
proceeding to the collection center (sink or base station) for
further analysis or processing.
Links to Other networks or
Similar Super Nodes
Super Node
 Formed by hundreds or
thousands of motes that
communicate with each
other and pass data along
from one to another
 Research done in this area
focus mostly on energy
aware computing and
distributed computing
Motes
MOTE (1)
 A very low cost low power computer
 Monitors one or more sensors
 A Radio Link to the outside world
 Are the building blocks of Wireless
Sensor Networks (WSN)
MOTE (2)
MOTE (3)
Functions and capabilities of mote are different:
Sensor nodes: the node that serves to read data or object being monitored environment,
this node is equipped with one or more sensor devices. These nodes can be divided into two
types. First, Node with standard capabilities and second, node that has been equipped with
a richer such as CCD camera, wireless LAN, logger, Webserver, etc.
Router: the node that serves to forward data packets from a node to another node. This
node is useful for multi-hop communication purposes. In a real application, we can program
a sensor node acts as a router.
Sink Node: the node that serves to collect sensing data from the sensor nodes, then
forward it to a device or another system, such as the database server for storage. Sink also
serves as a spreader package of device or another system to WSN, for example, for the
purposes of programming or reconfiguration of sensor nodes remotely
MOTE (4)
WSN Components
1. Transceiver, Serves to receive / send data using the IEEE 802.15.4 protocol to
other devices such as concentrator, Wifi modem, and RF modem.
2. Microcontroller, Serves to perform the function of calculation, and process
control peripheral devices connected to the microcontroller.
3. Power Source, Serves as a source of energy for WSN system as a whole.
4. External Memory, Serves as an additional memory for WSN system, basically a
microcontroller unit has its own memory unit.
5. Sensor, Serves to sensing physical quantities to be measured. Sensor is a
device that is able to convert a form of energy into another form of energy, in
this case the change of the measured amount of energy into electrical energy
which is then converted by the ADC into a row of quantized pulses that can
then be read by the microcontroller.
THE BASIC ARCHITECTURE OF WSN
 WSN consists of three sensor node and a Sink that
connect and communicate via radio waves.
 Sensor node 2 and sensor node 3 can communicate
directly (ad-hoc).
 Meanwhile, if you want to communicate with Sink
node, both of the nodes can send data packets via
the Sensor Node 1, Sensor Node 1 will forward the
packet to the Sink Node.
 Sensor Node 1 also acts as an intermediary (router)
to provide multi-hop communication.
 A WSN applications often involve lots of nodes
(hundreds to thousands).
WSN ARCHITECTURE IN GENERAL
A LANDSCAPE OF WSN
Illustration of the WSN usage Scenarios
THE SOFTWARE ON THE MOTE
WSN operating system that is widely used in the current time
1.
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5.
TinyOS
Contiki
Nano-RK
LiteOS
RTOS
• Operating system used on the sensor node network is not very
complex when compared with the operating system in general.
This OS is more similar to embedded systems because of two
reasons.
• First, WSN is applied to the function - specific functions.
• Secondly, WSN require inexpensive design and use of small
energy, so it is encouraging node - the node should use a low
power microcontroller.
• Microcontroller will not be running mechanism - a mechanism
that is not too important, for example, virtual memory, because it
was too hard to follow.
Hardware
• One of the challenges in the field
of WSN manufacture of the sensor
node is energy efficient and as
small as possible.
• Sensor nodes likened to a small
computer, with a basic capability
as part of the display and other
components in it.
WSN Implementation
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Monitoring Area
Monitoring keadaan lingkungan / alam
Agriculture/ Peratanian
Smart Home
Wearable Healthcare Devices
Driverless Vehicles / Automobiles
Monitoring Area
Monitoring the area is the most common application of WSN. In the area of
monitoring, WSN is placed in an area where there is a phenomenon that will
be monitored. The military uses to detect attacks or intruders, while civil use,
for example to enclose the pipe - gas or oil pipelines.
Monitoring the environment conditions or nature
Agriculture
Smart Home
 Sensors in WSN is capable of measuring a wide range of environmental data,
such as temperature, high-level / low noise, light intensity, and so forth, so that
the device or human can make decisions based on changes in the environment
around the house.
 For example: changes in the outdoor air temperature can we know the color
change lights in the room. Another example is the product Tado can set the
heating system based on the presence of people in the room, or based on the
weather.
Wearable Healthcare Devices
The development of our body's health can be monitored using
sensors embedded in clothing, for example: smart sensing by
Citizen sciences, or in a device that can be used, for example:
iHealth, PULSE or bracelet.
Driverless Vehicles / Automobiles
 Sensors installed on several parts of a car provides useful information
for the data processing center in the vehicle to prevent collisions.
 In addition, with the help of data from the processing of images from
the camera mounted on a car or assistance data from the GPS makes
the car can walk or park to their destination automatically.
 Several automotive companies like BMW, Chevrolet and Audi has
applied this technology into the flagship car.