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 • Encryptionkey
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.
