Download WSN

WSN
Wireless Sensors Network
Done By:
3bdulRa7man Al7arthi
Mo7mad AlHudaib
Moh7amad Ba7emed
Outline of WSN




Definition.
Applications of WSN.
How does WSN work?
Characteristics of WSN.
1.Definition
Definition:
Wireless sensor network (WSN) is a
computer network consisting of large
number of small devices distributed in
different places
Sensor Nodes:
What it does:
sense, process data , communicate
to each other
Consist of:
radio transceiver ,a small controller
,an energy source
Size and Cost:
ranging (shoebox- sized and a grain
dust).Varying (hundreds of dollars
and few cents(depend on complixcity and size))
2.Applications of
WSN
Common task
monitoring physical and environmental
conditions such as (temperature, sound,
vibration or pressure) at different locations
Many fields:
- Civilian applications
- Healthcare applications
- Environmental monitoring
- home automation
Typical applications:

monitoring, tracking and controlling

Example (monitor area)
3.How does WSN
work?
WSN Parts




Nodes sensor.
WSN Gateway.
Server.
Local Terminal.
Nodes Sensor:

Consist of :




Radio Transceiver or any other wireless
communications.
Data memory.
Small microcontroller. and
Energy source ”usually a battery”.
Nodes Sensors


When these nodes sense any movement or any
change, they should report it as a message to
the server through WSN Gateway. This is
called Upstream.
The server sends orders to nodes and ask them
to do appropriate response. This is called
Downstream.
WSN Gateway


Gateway is important because it is a device
where we can connect these nodes sensor to
the internet.
Gateway is the only component between these
nodes which has an IP address.
Server

There are two way to connect the server to
these nodes through gateway:



Ethernet.
Wi-Fi.
Data that is collected from nodes sensors are
saved into the server and can be access them
either as a web-page or as a database.
Local Terminals



Desktops.
PDAs.
Mobiles.
Big Picture of WSN
Big Picture of WSN
4.Characteristics.
4. Characteristics:




Power
Security
MAC
ROUTING








Reliability
Integration with wake/sleep schedules
Unicast, multicast and anycast semantics
Real-Time
Mobility
Voids
Security
Congestion
Power





Long Time Life.
Pair of AA Battery
Mobile phones live for few days without
charging……..power consumption in
milliamps range
While it is in micro amps range
HOW?

Hardware
-Software
Power

Hardware Level

Solar cell

Mechanical Energy (motion, wind)

More batteries, if size and form are not problems

Multiple states of power (ON-OFF-IDLE)
Power

Software Level:

Minimizing communications


well implemented protocols and algorithms
Schedule sleep/wake-up patterns


Some nodes are active in a period of time
Rotation
Security

Encryption and Authentication

Encryption key
MAC



Media Access Control
MAC protocols control the actions over the
shared media of connectivity.
In case the channel:



is busy.
There is collision
Doze Mode
ROUTING


Discover the neighborhood
Build a table consist of:






ID
Geographic location
remaining energy,
quality of the link and
delay via that node
In the next few slides some key issues
Routing

Reliability


Quality index
-delivery ratio
Integration with wake/sleep schedules:


doze mode
no transmitting to a sleep node.
Routing

Unicast, multicast and anycast semantics:




massage may include an ID with a specific unicast
node or the nearest one to the geographic destination
area multicast (around destination)
Any node in the destination area
Real-Time::


Hard to guarantee
The main factor is velocity
Routing

Mobility :



Complicated
Keep tracking
Voids:


No forwarding node
Path around it
Routing

Security:


????
Congestion :



Nowadays, not critical
Maybe in base station
Solution (decrease data rate, ignore less important
messages)
Thank for paying attention.
Please ask if there is something not
clear.