Practical Aspects of CTI WSN Testbed

Transcription

1 Practical Aspects of CTI WSN Testbed Dpt. of Computer Engineering and Informatics, University of Patras, Greece Research Academic Computer Technology Institute (CTI), Patras, Greece 2nd PROSENSE Meeting September 27 - October 1, 2008, Santorini

2 CTI s Sensor Testbed Current hardware 20 Mica2 nodes 19 TelosB nodes (with humidity, temperature and light sensors embedded) 12 MTS310 sensor boards (light, temp, mic, 2-axis accelerometer, magnetometer) 2 MTS420 (humidity, barometric pressure, temp, light, 2-axis accelerometer, GPS) 2 MTS400 (same without GPS) 3 MIB520 USB programming boards 3 MIB600 Ethernet programming boards 2 Stargate Netbridges

3 CTI s Sensor Testbed Current hardware (cont d) 45 Sun SPOTs (15 gateways, 30 sensor nodes) 32-bit CPU, 180MHz, 512KB RAM, 4MB Flash radio 3-axis accelerometer, temperature, light Java Squawk (fully Java ME capable) 5 PC Engines Alix base stations

4 CTI s Sensor Testbed Expected Early October 60 isense nodes 32-bit CPU, 16 MHz, 96KB RAM, 128KB Flash accelerometer, magnetometer, temperature, light, camera, IR, vehicle detection C++ 1-wire (IEEE 1451) sensors for weather data outdoors

5 Testbed Target Application Intelligent Building CTI s building is only a few years old (2005) but... Existing Building Management System (BMS) is not sufficient: BMS is restricted only to building sectors scope Finer monitoring and control needed... What about energy savings? Monitor building and control HVAC to some extent Possible energy savings in CTI s data center

6 Mica2 + TinyOS The greats: Mica2 s good battery life TinyOS 2.x better than 1.x in general - more services provided Better multihop, energy savings Good range

7 Mica2 + TinyOS (cont d) The not-so-greats: MTS4xx sensor boards not supported in TinyOS 2.x yet! Over-the-air reprogramming (Deluge) also not working on Mica2 s! Custom power connector (eventually solved)

8 TelosB + TinyOS The greats: Better support in TinyOS 2.x than TinyOS 1.x Very good battery life USB data + power connector really useful The not-so-greats: Additional sensor boards

9 SUN SPOTs The greats: Great software Java Great packaging no power wires cut by mistake, etc. Growing user base + available software USB connectivity Embedded breadboard good for prototyping 3-axis accelerometer (Relatively) Cheap!

10 SUN SPOTs (cont d) The not-so-greats: Battery life not that great Transmission range not that great either (10 15m maximum) Integrated light and temp sensors not very impressive

11 ALIX Base Stations AMD 256MB RAM, 4GB Compact Flash, 2 or 4 USB, LAN, WLAN Really small factor (Mini-ITX) 4W Consumption Xubuntu Cheap :)

12 ALIX Base Stations (cont d)

13 isense platform

14 isense The hardware is arranged around a core module with an IEEE compliant radio 32-bit microcontroller running at 16MHz, 96kbytes of memory quite powerful compared to MICAs and TelosB A set of sensor boards, which are stackable (i.e., they can be combined): Measurement Module (prototyping) Vehicle Detection Module (magnetometer) Security Sensor Modules (PIR camera + accelerometer) Environmental Sensor Module (temp + light) GPS Module

15 isense (cont d) Offers a comprehensive software system Free, but not open source :( C++ Set of libraries to use within your applications (working) Application code is directly used in the Shawn simulator

16 CTI Building Layout 5 levels - 2 or 3 sectors in each level BMS (Honeywell) can control HVAC of sectors, i.e., not specific to rooms No documentation available, uses PLCs no interfacing to the system possible in polynomial time Mostly security-wise functions + control power for each building sector

17 Testbed Application - Scope CTI electricity bill: could be better :) Main contributions to this: Air-conditioning in the spring-summer Lights Data center power consumption Could be done in other ways, but it won t be easily controllable

18 Testbed Application - CTI Data center Free cooling Large part of energy spent on data centers is due to cooling BMS not really smart on this subject Idea: use external (cold) air to cool the data center Problem: humidity Solution: use WSN to monitor extensively the data center and use cool air whenever possible

19 Testbed Application - CTI Data center (2)

20 Testbed Architecture First step setup testbed on Research Unit 1 level Second step setup testbed on CTI s data center Primary goals: monitor & control to save energy Problems: connectivity, steel doors, thick walls, etc. Control not yet implemented

21 Testbed Architecture (2) Third step setup testbed on CEID buildings (2) Only monitoring on CEID no control available Maybe use some mobile nodes as well

22 Testbed Architecture (3) Use a number of dedicated base stations to interface to the sensor network level (connectivity problems) Use USB or AC adapters to power most of the nodes (not really wireless but 100% on ) Use a number of SW peers in each part of the testbed to unify the whole testbed

23 Testbed Architecture

24 Testbed Architecture (5)

25 WebDust s Goals Overview Unify multiple WSNs Offer services such as WSN monitoring and administration Co-operate with and work on top of various HW and SW Provide an easy to use and open API

26 SW Overview

27 Overview of Architecture P2P architecture Layers: Core, Control and Sensor The sensor layer includes sensor devices and the respective software The control layer includes sensor network gateways and software The core layer provides WebDust services based on the functionalities the other two provide P2P and Web Interfaces available

28 Persistence Layer Hibernate Object/Relational Mapping is the automated persistence of objects in a Java application to the tables in a database Use metadata to describe the mapping between the objects and the database An API e.g., for performing basic CRUD(Create, Read, Update, Delete) operations on objects of persistent classes

29 Hibernate High performance object/relational persistence and query service Lets you develop persistent classes following object-oriented idiom Great programming ease!

30 ER Diagram

31 Topology of separate testbeds

32 Technologies Used Java JXTA Hibernate (persistence layer) Currently MySQL, maybe HSQL in the future TinyOS 2.x (Mica2, TelosB) and SPOTS on the sensor level

33 Current Status Services Discover other peers Monitored sensors share their readings Web interface Basic sensor-level functionality implemented for SPOTs and TinyOS

34 Current Status Interface Simple web interface provide basic administration stuff Google Maps used in the web interface Google Earth Browser Plugin 3D visualization inside your web browser Going from 2D to 3D is easy Patras University Campus in 3D 90% (Google 3D warehouse)

35 Examples of the Web interface

36 Examples of the Web interface

37 Future Work - Univ. of Patras

38 Interfacing your SW with WebDust A driver is needed so that readings from your system can be read from WebDust Simple porting interpret messages coming from sensor gateways Basic functionality only monitoring supported as of now

39 Driver Example Driver must be able to return device network ID and device type In general, the driver must register a listener for messages coming from the network Observable entities, other listeners, peers, applications are notified of new messages by the driver

40 Driver Example SPOT SPOTs sample their temp and light sensors periodically If there is a route to a base station, reading messages are sent, otherwise nodes store them and transmit them whenever a route to any ase station has been established Nodes create events when they are in the range of a base station

41 Driver Example TinyOS For TinyOS 2.x we used Octopus as a start, added some tweaks, further development needed The driver essentially connects to the Serial Forwarder Reads and interprets incoming reading messages Informs other listeners of the incoming reading messages

42 Future Work isense installation and integration with the system Further sensor-level extensions for control and monitoring Web interface Documentation! Up and running Mid November

43 Related Testbed - Microsoft SenseWeb SenseWeb is a peer-produced sensor network that consists of sensors deployed by contributors across the globe It allows developing sensing applications that use the shared sensing resources and our sensor querying and tasking mechanisms SensorMap mashes up sensor data from SenseWeb on a map interface Provides interactive tools to selectively query sensors and visualize data Authenticated access to manage sensors

44 Related Testbed - SensorMap

45 Related Testbed - Swiss Experiment A number of existing WSN testbeds - mainly environmental monitoring Unification of interface created to provide a platform for large scale sensor network deployment and information retrieval and exploitation Uses SensorMap and Google Maps to export data Good example of testbed unification

46 And now something completely different...

47 Fun in Numbers (FinN) FinN is a platform for developing mobile, locative and collaborative distributed games The platform is implemented using a combination of JAVA Standard and Mobile editions, targeting also mobile phones that have some kind of sensors installed Players interact with each other and their surrounding environment by moving, running and gesturing as a means to perform game related actions

48 During gameplay Each player carries a wireless sensing device that executes a software component (player peer) Player peers communicate with a collection of stations that form a wireless backbone infrastructure (alix) Stations are used to monitor the evolution of the game and interact with nearby players Users can use the sensors and buttons to explicitly trigger actions for interaction

49 Architecture

50 Architecture Game engine During the initialization of the system one station peer becomes the game engine, responsible for coordination of the infrastructure The stations communicate with the users devices either through local ad-hoc networks or via personal area non-ip networks They provide location-aware and context-aware services to the player peers

51 Architecture World Peer The game engine communicates with the world peer, a central peer that is accessible via the Web and offers high level services (maintains the player records, gathers statistics, game history) The world peer is updated asynchronously to avoid computational and communication overhead

52 Cool How does that relate to the testbed? Mobile node extensions Monitor activity inside the building Control extensions gestures Many possible scenarios

53 Cool How does that relate to the testbed? (2) SW by Sun provides AODV routing We implemented DSR routing for SPOTs Communication primitives

54 Cool How does that relate to the testbed? (3) Gesture recognition Some simple gestures recognized for now Gestures and pressing buttons generate events Presence inside base station range generates events