Technology and Performance of TUTWSN Wireless Sensor Network 1
TUTWSN technology 2
Wireless Mesh Sensor Network Sink Samples own data and sends to router Sink Receives data from other nodes Samples own data and routes other nodes data Sink 3
Mesh network node types and roles without routing can only sample and send its own data Routing node receives data from other nodes and forwards it towards sink(s) Sink requests data from other nodes. It can be normal routing node but consumes the data and does not forward it to other WSN nodes. Controller (one per network) is an entity that coordinates node addressing, routing, joining network... (no router) (router) Sink Controller Namings: Subnode (TUTWSN) End device (ZigBee) Leave node Namings: Headnode (TUTWSN) Router (ZigBee) Namings: Gateway (TUTWSN) ( that forwards data to other networks) Namings: PAN Coordinator (ZigBee) (Note: TUTWSN does not have central controller) 4
ZigBee Network End Device Router End Device End Device Router Router PAN Sink coordinator Coordinator acts also as gateway to transfer data between WSN and other networks Only one coordinator/gateway per network New node must ask permission from coordinator to join network (might take much time) Max 65k nodes in one network Failure of coordinator is critical to whole network 5
TUTWSN Subnode Subnode Gateway Headnode Headnode Headnode Subnode Gateway No coordinator, distributed control in all nodes Arbitrary number of gateways to other networks Gateways do not control the network since they are normal headnodes New nodes can join network quickly by synchronizing to nearest neigbours s can move with respect to others re-routing takes place all the time s make routing decisions by themselves No single point of failure 6
TUTWSN meets all the requirements Large network TUTWSN Low-power Mobile 7
What is TUTWSN technology? TUTWSN application and tools back-office TUTWSN mesh technology Gate way Gate way 2.4 GHz and 433 MHz platforms 8
TUTWSN key features Autonomous adhoc multihop networking No single point of failure Multiple routes through network Multiple gateway points Supports movement and rapid changes in surroundings Adding and removing of nodes Low power consumption Years of operation with AA batteries Energy efficiency also in router nodes Large network sizes (density and number of nodes) Network is programmable and firmware can be updated on-the-field Used in real application deployments Gate way Gate way 9
SensorOS Luminanne Temperature M2M Self Diagnostics Asset tracking Sensors and actuators TUTWSN platform lux T PC CO2 G is an embedded real-time system running protocols and sensor tasks Different types and number of physical sensors are attached according to customer requirements e.g. PIR, acceleration sensor, humidity, temperature, luminance, CO2, magnetic, power consumption Interfaces for RS232, digital I/O, Ethernet (TCP/IP), GPRS, wireless 2.4GHz Off-the-shelf components Platform components are replaceable Mesh technology implemented in TUTWSN firmware Applications SensorAPI TUTWNS Transfer TUTWSN Routing TUTWSN MAC Hardware abstraction layer Processors Radios 10
TUTWSN Hardware platforms 11
TUTWSN (2.4GHz) Printed Circuit Board Loop antenna Casing Battery holder Pushbutton 2xLed Lux sensor Extension area for add-on sensors 3D vibration sensor (shock detection) On-board temp sensor Casing holder 12
Casing PCB TUTWSN (433MHz) PCB antenna Pushbutton 2xLed Lux sensor Extension area for add-on sensors 3D vibration sensor (shock detection) On-board temp sensor Battery holder Extended battery Solar panel option External sensor cord 13
Extended TUTWSN s External sensors on expansion cable External temperature Sensor (without protective enclosure) External humidity Sensor (without protective enclosure) 14
TUTWSN Gateway (2.4GHz) Printed Circuit Board Casing Loop Antenna Processor Expansion area for add-on sensors Serial port connector (UART, RS-232) Ethernet module DC-connector Supports Power over Ethernet DC levels 15 Ethernet connector
TUTWSN Gateway (Serial Port to GPRS modem) TUTWSN Gateway serial port version (Ethernet module not assembled on PCB board) GSM and GPS antenna cable connectors GPRS modem GPS receiver RS-232 Cable 16
Extended TUTWSN s CO2 sensor Indoors motion detection sensor Humidity sensor 17
TUTWSN Performance 18
WSN Design Space Lifetime (energy efficiency) Intelligence (data processing in WSN Sampling interval Autonomy (install, use, modify network) Transmission delay 5 4 3 2 1 Throughput Transmission reliability Network size (number of nodes) density 19 Robustness (node mobility, self-healing) Range (hop distance)
Most important requirements for WSN operation Scalability Large networks, thousands of nodes Dense networks, hundreds of nodes in a range Constantly changing environment new nodes join, some leave the network RF wave propagation conditions are varying some nodes may be mobile Robustness, availability, reliability 20
Performance TUTWSN Low-energy monitoring 21
TUTWSN 10-hop testing configuration 2175 2179 2240 2172 2313 2256 2323 500m 2273 2341 2184 2235 2223 2250 2261 2255 Gateway 2313 2341 22
Samples received This was requested interval TUTWSN low-energy version 10-hop reliability report 100.00 % 95.00 % 90.00 % 85.00 % 80.00 % 75.00 % 70.00 % The 10-hop TUTWSN network reaches 98% reliability for 60 sec 100% of requested packets arrive in 500 sec Lives ~2 years with AA batteries 65.00 % Best node 60.00 % Average Worst node 55.00 % 23 50.00 % 0 60 120 180 240 300 360 420 480 540 600 Period: 27.11.2008 19:00-28.11.2008 19:00 Reception intervals (s)
TUT Tietotalo deployment All four floors in TUT Tietotalo for indoors deployment Two outdoor areas Tietotalo included Outdoor area 2 nodes included Outdoor area 1 nodes included 24
Samples received TUT Tietotalo TITWSN low-energy reliability 20.10.2008 25.1.2009 Total 1.5 Gb of plain data samples 100 % 95 % 90 % 85 % 80 % 75 % 70 % 65 % 60 % 55 % 50 % Requested intervals have been changed during operation between 30s, 60s, 120s, For all intervals reliability is over 97% Note max hop count 10, average 5 160 nodes in network Router node lifetime about two years 2xAA lithium Best node Average Worst node 0 60 120 180 240 300 360 420 480 540 600 Reception intervals (s) 25
Performance TUTWSN Low-latency monitoring 26
TUTWSN Low-latency monitoring G R M Gateway node Ethernet connection Power supply Sensors Router node Power supply Sensors Moving node Battery optimised Sensors Alarm button G R M 27
TUTWSN Low-latency set-up 1 Gateway, 8 Router nodes All nodes were transmitting data packets Typical office environment 28
hop count TUTWSN Low-latency monitoring End-to-end delays at different hop counts 29
TUTWSN Low-latency monitoring 30
TUTWSN Low-latency monitoring Despite the hop count 99% of packets were received below 2.11 s 99,5% 2.53 s 99,9% 3.63 s 100% 4.43 s Average delay / hop 99%: 0.346894 ± 0.045416 s 99,5%: 0.403129 ± 0.051503 s 99,9%: 0.536735 ± 0.053239 s 100%: 0.684876 ± 0.049331 s No packet loss, no duplicates 31