Wireless Sensor Networks in Ambient Intelligence - TSB - UPV

Wireless Sensor Networks in Ambient IntelligenceLuis Fernández (luiferlu@itaca.upv.es), José M. Blasco (joblabuc@eln.upv.es), José F. Hernández(johercu1@itaca.upv.es) , Eduardo Montón (edmonsan@itaca.upv.es)Technologies for Health and Well-beingInstituto ITACAUniversidad Politécnica de ValenciaAbstractThe Wireless Sensor Networks (WSN) is anecessary technology for the development of theconcept of Ambient Intelligence where users areprovided of services depending on their context.The WSNs provide the dynamic and flexiblestructure for the transmission of data acquired fromthe environment by the sensors. This data is thebase for the development of ambient intelligentservices adapted with the information acquiredfrom the sensors. In addition, the same WSNmakes possible the communication with actuatorswith possibilities of performing physical changes inthe environment.KeywordsWireless Sensor Networks, Wireless Body AreaNetworks, Zigbee, Ambient Intelligence.1. IntroductionThe concept of Ambient Intelligence (AmI) is thenew paradigm for providing future applications inthe Information Society, hiding the complexity ofthe technology, offering the intelligent servicesdepending on the context of the user and throughnatural interfaces. For the development of thisconcept it is necessary to gather information aboutthe user and the environment in order to be able ofknowing the context of the mentioned user. TheWSN addresses this necessity providing a wirelessand flexible structure for the transmission of thedata acquired by sensors to a system in charge ofprocessing this information. In addition, it is alsopossible to use these type of networks tocommunicate with actuators that make actions inthe environment of the user.2. Features of Wireless Sensor NetworksThe principal feature of a WSN is to transmitwirelessly the data, acquired by sensors in differentenvironments, to the elements (in the same networkor in other) in charge of processing thisinformation.Usually these networks are composed by a greatnumber of nodes. This means that somecharacteristics as small size, low powerconsumption, low complexity and low cost aredesirable goals when designing a WSN.Using a system that needs the batteries to becharged every day can become a quite annoyingtask if the number of devices is quite high. Inaddition if each device in the system is complex asmuch to design as to manufacture, this system isnot going to be cost-effective to the market. Forthis reasons users expect batteries to last months toyears, and designers expect a simple technologywhich implies quick and simple designs in order toget globally standard cheap systems.Every technology, protocol and topology designedfor and related to WSN must take into accountthese characteristics. Protocols must ensure thenodes to realize simple tasks in order to simplifytheir functionality and they must ensure too that thetransmitters and receivers works the minimumpossible time in order to reduce powerconsumption and increase in this way the batterylife, and, of course, everything must be done at aprice that allows an affordable cost for a networkthat integrates a high density of nodes.A. TopologiesIn the wide range of scenarios for WSN, it isimpossible that one network topology could resolveoptimally all the requirements, so there aredifferent topologies [1, 2] for different scenarios.Two are the main topologies used in WSN:• Start Network• Mesh NetworkThe star topology is useful in WSN, especially inthe development of Wireless Body Area Networks,WBAN. In this topology, a central node has the

esponsibility of the coordination with the medicalsensors and the communication outside the BAN.or processing the sensor data. This topology is usedwhen the sensors are located in a wide area.The current developments in WSN are also focusedon mesh network topology because it allows for thecommunication between devices without a centralnode for routing using a mesh of nodes. Thisfeature eliminates the central failure, and providesself-healing and self-organization. The selforganization provides more robustness than a statictopology, and allows having mobile devices. Forproviding this functionality, the current research isworking in new algorithms and optimizingalgorithms, for self-routing and giving intelligenceto the nodes.Star network: in this case the network is formed bya central element, in charge of controlling thenetwork, which receives the information fromwireless sensor end-point nodes. These arephysically similar to the mesh network nodes. Theend-point nodes send data directly to the centralcoordinator. From there, data is relayed to othersystems. Star networks offer the fastest datagathering speed. The star network topology istypically used in Body Area Networks (BAN), alsocalled Body Sensor Network (BSN) [3], wheresensors are located on the body of a person.Figure 2. Mesh WSN topologyIn both cases, it is usual to have a gateway tocommunicate with other local or wide areanetworks. In the case of a mesh network this taskcan be performed by one or several of the nodeswhich would have additional electronics and, in thecase of the star network, the network coordinator isin charge of this task.B. Wireless Technologies & ProtocolsThe development and standardization of new lowpower consumption and short range wirelesstechnologies have enabled the wireless sensornetwork concept. Today, there are several optionsfor the development of WSN. These technologiesspecify the Physical and MAC levels (ex., IEEE802.15.4), the Network levels (ex., Zigbee) or thethree levels in the same specification (ex.,Bluetooth). There is also one special OperativeSystem developed to run in the nodes of a WirelessSensor Network, this Operative System is calledTinyOS [4].Figure 1. Start WSN topologyMesh network: it is formed of several modules,usually consisting of a battery, RF adapter,microcontroller, and sensor board, although not allthe nodes include sensors. Each wireless node actsas a router, sending and receiving data from othersensors or the gateway. Self-organizing networksautomatically determine the best path for data totake from sensor to gateway. Data is automaticallysent around failed sensor routers. Because of thelimitations, due to battery life, nodes are built withpower conservation in mind, and generally spendlarge amounts of time in a low-power "sleep" mode802.15.4The scope of IEEE 802.15.4 task group [5, 6], asdefined in its original Project AuthorizationRequest, is “to define the PHY and MACspecifications for low data rate wirelessconnectivity with fixed, portable and movingdevices with no battery or very limited batteryconsumption requirements”. Furthermore, thepurpose of the specification is “to provide astandard for ultra low complexity, ultra low cost,ultra low power consumption and low data ratewireless connectivity among inexpensive devices”.The characteristics of 802.15.4 make this

technology one of most interesting for thedevelopment of BAN [7].IEEE 802.15.4 is specified to work in threedifferent sub-bands of the ISM band (2.4 GHz, 915MHz in USA and 868 MHz in Europe), withthroughputs of 250 kbps, 40 kbps and 20 kpbsrespectively. Although the higher frequency makesthat for a power transmission given, the range isshorter, this is one of the unlicensed band, moreexpanded in the world.Channel access is contention based, via a carriersense multiple access mechanism with collisionavoidance (CSMA-CA). A “battery life extension”mode is also available the period of transmission toa fixed time of approximately 2 ms.IEEE 802.15.4 specifies the physical layer andportions of the data link layer (DLL). The higherlayerprotocols are left to industry (Zigbee) and theindividual applications.Table 1. IEEE 802.15.4 in the ISO-OSI layerednetwork modelISO-OSI Model IEEE 802 Model7. Application6. Presentation5. Session4. Transport3. Network2. Data link1. PhysicalIEEE 802.2LLC, type ISSCSHigher layersOther LLCIEEE 802.15.4 (MAC)IEEE802.15.4868/915 MHz(PHY)IEEE802.15.4 2.4GHz (PHY)ZigbeeThe Zigbee Alliance [8] is an IndustrialConsortium of chip manufacturers, OEMmanufactures, service providers, and users in thewireless sensor network market. This Consortiumis carrying out the task of association of specifyinghigher-layer standards, based on IEEE 802.15.4.This includes network, security, and applicationprotocols.The Zigbee standard specifies both mesh and starnetwork topologies. There are two physical devicetypes for the lowest system cost to allow vendors tosupply the lowest possible cost devices: fullfunction devices and reduced function devices.• Full function device (FFD):o Can function in any topology.o Capable of being the Networkcoordinator.o Can talk to any other device.• Reduced function device (RFD).o Limited to star topology.o Cannot become a network coordinator.o Talks only to a network coordinator.o Very simple implementation.Zigbee is an incipient standard that covers thenecessities of the network layer in the wirelesssensor networks, supported by importantcompanies like Philips, Samsung, Motorola,Mitsubishi Electric, Cisco Systems, Epson, etc.BluetoothBluetooth (BT) [9] is a radio wave basedtechnology for short-range wireless connectivityamong portable and/or fixed electronic devices,such as cellular phones, headsets, personal digitalassistants and laptops, as well as for theirconnectivity to the Internet. The BT specificationconsists of the core and the profile part: the corepart defines how the BT technology works and theprofile part describes how the BT technology isused in specific scenarios and use cases. Thestandard specifies from the physical to theapplication layer.Radio frequency operation is in the unlicensedIndustrial, Scientific and Medical (ISM) band at2.4 to 2.48 GHz, using a spread spectrum,frequency hopping, full-duplex signal at up to 1600hops/sec. The signal hops among 79 frequencies at1 MHz intervals, to give a high degree ofinterference immunity. RF output is specified forthree different types:• 0 dBm (1 mW) for a communication range ofless than 5 m.• 4 dBm (2.5 mW) for a communication rangeof 10-20 m.• +20 dBm (100 mW) for a communicationrange of around 100 m.The Bluetooth 1.1 specification defines a lowpowerradio link capable of voice or datatransmission to a maximum capacity of 720 kbpsper channel.The IEEE 802.15.1 Group Task [10] provided astandard adaptation of the Bluetooth Specification

v1.1 Foundation MAC (L2CAP, LMP, andBaseband) and PHY (Radio).The use of Bluetooth, although more extended thatZigbee is more focused on the personalcommunications and essential problems, like thepower consumption or the synchronization in theBAN, could not be managed with this technology.UltraWideBandUltra-Wideband (UWB) technology has theobjective of providing the convenience andmobility of wireless communications, to highspeedinterconnect devices throughout the digitalhome and office. Designed for short-range,wireless personal area networks (WPANs), UWBwants to become the leading technology for freeingpeople from wires, enabling wireless connection ofmultiple devices for transmission of video, audioand other high-bandwidth data.UWB, short-range radio technology, complementsother longer range radio technologies, such asWiFi, Wi-Max, and cellular wide areacommunications. It is used to relay data from a hostdevice to other devices in the immediate area (up to10 meters).A traditional UWB transmitter works by sendingbillions of pulses across a very wide spectrum offrequencies, several GHz in bandwidth. Thecorresponding receiver then translates the pulsesinto data by listening for a familiar pulse sequence,sent by the transmitter. Specifically, UWB isdefined as any radio technology having a spectrumthat occupies a bandwidth greater than 20 percentof the centre frequency, or a bandwidth of at least500 MHz.Modern UWB systems use other modulationtechniques, such as Orthogonal Frequency DivisionMultiplexing [11] (OFDM), to occupy theseextremely wide bandwidths. In addition, the use ofmultiple bands in combination with OFDMmodulation, can provide significant advantages totraditional UWB systems.UWB's combination of broader spectrum and lowerpower improves speed and reduces interferencewith other wireless spectra. In the United States,the Federal Communications Commission (FCC)has mandated that UWB radio transmissions canlegally operate in the range from 3.1 GHz up to10.6 GHz, at a limited transmit power of -41dBm/MHz. Consequently, UWB providesdramatic channel capacity at short range, that limitsinterference.In June 2003, the MultiBand OFDM Alliance(MBOA) was formed, with many of the mostinfluential players in the consumer electronics,personal computing, home entertainment,semiconductor, and digital imaging marketsegments. The goal of this organization is todevelop the best technical solution for theemerging UWB (IEEE 802.15.3a Task Group [11])Physical and MAC specification for a diverse set ofapplications. To date, MBOA has more than 60participants that support a single technical proposalfor UWB.UWB is a technology in the physical level of theOSI stack. There are protocols as Bluetooth,Zigbee, USB [12] that are studying to includeUWB in theirs physical layers.This new technology is being studied is severalprojects for the development of WBAN [13, 14,15].Table 2. Wireless Technologies for WSNZigbee Bluetooth UWBRange Up to 100m Up to 100m Up to 10mThroughput 250 kbps 720 kbpsTransmission levelsPHY/MAClevelsNetworkleveldefinitionOEMmodules inthe market0 dBmIEEE802.15.4Yes(Piconet,Scatternettopologies)IncipientpenetrationSoftware, TinyOS0 dBm, 4dBm or 20dBmIEEE802.15.1Yes (Mesh,Startopologies)Highpenetration480 Mbps(10 m.)100 Mbps(3 m.)-41dBm/MHzIEEE802.15.3aNoLowpenetrationTinyOS [4] is an open-source operating system,designed for wireless embedded sensor networks. Itfeatures a component-based architecture, aimed atenabling rapid innovation and implementationwhile minimizing code size, as required by thesevere memory constraints inherent in sensornetworks. TinyOS's component library includesnetwork protocols, distributed services, sensordrivers, and data acquisition tools -all of which canbe used as- is or be further refined for a customapplication. TinyOS's event-driven executionmodel enables fine-grained power management, yet

allows the scheduling flexibility made necessary bythe unpredictable nature of wireless communicationand physical world interfaces.TinyOS has been ported to over a dozen hardwareplatforms and numerous sensor boards. A widecommunity uses it in simulation, to develop andtest various algorithms and protocols. New releasessee over 10,000 downloads. Over 500 researchgroups and companies are using TinyOS on theBerkeley/Crossbow Motes. Numerous groups areactively contributing code to the sourceforge siteand working together to establish standard,interoperable network services, built from a base ofdirect experience and honed through competitiveanalysis in an open environment.3. WSN nodesThe principal device in a WSN is the networknode, also called mote. This device, batterypowered, has the RF communication for thetransmission and the reception of the information,an interface between the module and the sensor anda microcontroller.Normally this microcontroller is a simple 8-bitmicrocontroller. Since, as commented above, oneof the main goals when designing nodes in WSN issimplicity, this kind of processors must be enoughpowerful to manage communications, and their lowclock frequencies reduce power consumption, thusincreasing the battery life.Depending on the size and shape requirements,batteries will be a key factor in the design of thenodes. Normally batteries are the bottleneck of thedesign when referring to size. The higher thecapacity of the battery is needed the bigger the sizeis. A trade off between these two parameters mustbe done. Plenty of commercial batteries areavailable in the market: Lithium-Ion rechargeablebatteries, small coin batteries, high capacity Ni-Cdbatteries, etc…Regarding the transceivers for the RF part of thedevice, normally similar options are available fromdifferent manufacturers. This allows the designersto choose between different prices andcharacteristics depending on the needs of eachdesign.In the tables 4 and 5 a list with the commercialmodules available in the market and theirscharacteristics is included.

Table 4. Commercial Modules for WSNDescriptioniMote2 iMote MicaZ TelosB MICA2DOT(MPR500CA)Intel low power wirelesssensor moduleIntel low powerwireless sensormoduleLow Power WirelessSensor ModuleLow PowerWireless SensorModule withUSBSmall Size Low PowerWireless SensorModule (no 802.15.4)Mica2Low Power Wireless SensorModule (no 802.15.4)Operative System TinyOS TinyOS TinyOS TinyOS TinyOS TinyOSCompany Intel Intel Xbox XBOX XBOX XBOXData Rate 250Kbps 720kbps 250kbps 250 kbps FSK data rate up to76.8 kBaudRF transceiverBluetooth CC2420 CC2420 cc1000 cc1000FSK data rate up to 76.8kBaudChipCon CC2420Frequency 2,4 GHZ 2,4GHz 2,4GHz 2,4 Ghz 868/916MHz, 868/916MHz, 433MHz or433MHz or 315MHz multi-channel315MHz multichannelMicrocontroller Intel® PXA 271 Atmega128L, 8 MHz Atmega128L, 8 TI MSP430 ATmega128L ATmega128LXscale®MHzPowerRequirementsCurrentdeployment stateUltra low voltage at lowspeeds (0.85V up to 104MHz)Deep sleep (0.1mW)Deep sleep 1 uA 8 mA (active);

Table 5. Commercial Modules for WSNTelosA tmoteSky EM250 EM260 CC2430Description Low Power Wireless Low Power Wireless Chip with Chip with ZigBee Chip with ZigBeeSensor Module with Sensor Module with ZigBee System-on-Chip (micro System-on-Chip (microUSB (discontinued), USBSystem-on- and transceiver) - and transceiver) -new version calledChip (micro EmberZNet Stack (mesh ZigBee protocol stacktmoteSkyandNW included) (Z-Stack)transceiver)Operative TinyOS TinyOS Custom Custom Custom (Airbee)SystemCompany Moteiv - Moteiv Ember Ember ChipconData Rate 250kbps 250kbps 250kbps 250kbps 250kbpsRF transceiver CC2420 CC2420 Custom Custom cc2030Frequency 2,4Ghz 2,4Ghz 2,4Ghz 2.4Ghz 2,4GhzMicroControladorTI MSP430 TI MSP430 embedded 16-bit XAP2microcontroller16MHz8051 8-bit single-cyclemicrocontrollerPowerRequirementsCurrentdeploymentstate19 mA (active- radio 19 mA (active- radio 1uA max (deep 1uA max (deep sleep), RX +CPU->27 mA, 0.6on), 2.4 uA (sleep) on), 5 uA (sleep) sleep), 29mA 26mA (RX+CPU) uA sleeping(RX+CPU)Discontinued on sale pre-order pre-order Pre-order

4. Wireless Sensor NetworksApplicationsThe number of potential applications of sensornetwork technology is growing all the time.Applications of WSN technology include:• Remote Control and Monitoring in industrialSystem• Home Automation and Security• Inventory and Logistic• Natural Environment Monitoring• Agriculture• Human Interface Devices• Military Monitoring• Health Monitoring [16] (i.e.BAN)• Etc.The following table includes a table of WirelessSensor Networks projects developed in theEuropean Union (Body Area Networks are notincluded).Table 3. Mesh Networks projectsName Description WebWiSeNts Cooperating EmbeddedSystemsforExploration andControl featuringWireless SensorNetworksEYES self-organizing andcollaborative energyefficientsensornetworksHogthrob Networked on-a-chipnodes for sowmonitoringIntairner Intelligent AirMonitoring Networkfor monitoring thequality of the air.LakeNet Embedded SensorNetwork forEnvironmentalMonitoringRUNES ReconfigurableUbiquitous NetworkedEmbedded Systemswww.embedded-wisents.org/www.eyes.eu.orgwww.hogthrob.dkwww.nd.edu/~lemmon/lakenetproject/lakenet.htmlwww.istrunes.org/SPOTDTS/SNADAOptimaGoodFoodtechniques for securelocalization of wirelessdevices in sensornetworksDelay TolerantNetworks / SensorNetworksAdvanced DistributedNetwork forTelemonitoringServices, Air QualityMonitoringWireless SensorNetwork for thelocalization of patientsin a hospitalenvironment usingBluetoothWSNs for Food Safetyand Quality MonitoringBody Area Networkshttp://imm.dtu.dk/sens/secloc.htmlhttp://www.sics.se/cna/dtnsn/index.htmlwww.ada-ist.org/http://ami.goodfood-project.orgOne special case of WSN is the Body AreaNetwork (BAN). A BAN has compact units whichenable transfer vital signs from the body of the userbetween the user’s location and the clinic or thedoctor. There are a lot of projects that use BAN formonitoring the state of the patients.This section gathers some relevant examples ofprojects related with BAN technologies and acomparison of their characteristics.SensationSENSATION, an European project, researchesmicro and nano sensor technologies with the goalof monitoring, detecting and predicting the humanphysiological state in relation to its alertness,fatigue and stress at anytime, in anyplace and foreveryone.Web Site: http://www.sensation-eu.org/index.htmlMobiHealthThe MobiHealth European project has developed acustomisable monitoring system for vital signals,based on a BAN [17] and an m-health serviceplatform, utilizing UMTS and GPRS networks. The

prototype includes Bluetooth for thecommunication intraBAN and the central device isa PDA.Web Site: http://www.mobihealth.org/VitaSensVitaSens [18] is a wireless Body Area Network,developed by the Fraunhofer Institute forIntegrated Circuits in Germany. The BANdeveloped includes ECG, PSO2, temperature,blood pressure and respiratory sensors. The firstprototype has been developed using Bluetooth forthe communication between sensors and the centralunit, whereas -currently - is being adapted to -Zigbee for this communication.Web Site: http://www.ban.fraunhofer.de/Human++Human++ project of the InteruniversityMicroElectronics Centre of Belgium is developinga WBAN [15]. The objectives of the researchincludes Micro-Power generation (vibrational andthermal scavenger) for increasing the lifetime ofbattery-powered devices, 4ltra low-power radios,using UWB (IEEE 802.15.4a), Biosensors (DNAsensors), MEMS, EEG, etc.Web Site: http://www.imec.be/human/UbimonUbimon [19] is a research project, aimed at thedevelopment of an Ubiquitous MonitoringEnvironment for Wearable and ImplantableSensors. This project has developed a BSN,including ECG, SPO2, accelerometer, temperatureand humidity sensors. In this research, a RFmodulehas been developed, based on IEEE802.15.4 technology (CC2420 RF transceiver), theTinyOS and the transceiver CC2420. A CompactFlash-802.15.4 has been developed for PDAs andalso software for Data Mining.Web Site:http://www.doc.ic.ac.uk/vip/ubimon/home/index.htmlCodeblueThe University of Harvard in USA is carrying outthe Codeblue project [20]. This project is exploringapplications of wireless sensor network technologyto a range of medical applications, including prehospitaland in-hospital emergency care, disasterresponse, and stroke patient rehabilitation, andlocalization with RF (MoteTrack Project). Themain development of this project is a WBAN withbattery-powered "motes” and medical sensors(ECG, SPO2, Motion, EMG). The RF technologyis based on the 802.15.4 standard, TinyOS andMica and Telos modules.Web Site:http://www.eecs.harvard.edu/~mdw/proj/codeblue/PRIMA: Portable Remote Intelligent MedicalAgentsThe PRIMA project of the University of Galway inIreland is focused on the research, design, andevaluation of a prototype intelligent agent basedsystem for portable/remote monitoring andmanagement of at cardiac risk patients. In thisproject a WBAN, with an ECG smart sensor,Neural Networks, and RF localization usingBluetooth, has been developed. At the end of thePRIMA project, a spin-off called Syncrophi hasstarted the project BIOSENSE . In this project aWBAN using Zigbee will be developed.Web Site:http://ecrg.it.nuigalway.ie/projects/prima.htmlWBAN-ETHThis project, of the Swiss Federal Institute ofTechnology of Zurich, is developing a WirelessBody Area Network [14] of non-invasive sensorswith energy efficiency, unobtrusiveness, scalabilityand cost structure. The RF technology is UltraWide Band, from 3 to 6 GHz, and the current workis focused on the effects of body blocking withUWB. The objective of the project is to support ahigh density of heterogeneous nodes (about 50 perbody).Web Site:http://www.nari.ee.ethz.ch/wireless/research/projects/ban.htmlBasuma: Body Area System for UbiquitousMultimedia ApplicationsThis project is funded by the German Government,with the collaboration of universities and PhilipsResearch. They are developing a wireless BAN thatallows for monitoring heart rate, blood pressure,etc. The BAN should be able to make intelligentdecisions about the state of health and send theinformation to the medical services. It is mainlybased upon UWB technology.Web Site: http://www.basuma.deMOTETRACKThis project has been developed in the Universityof Harvard (USA). In this project has beendeveloped a RF-based location tracking system. Itis based on low-power radio transceivers coupledwith a modest amount of computation and storage

capabilities, such as the Berkeley Mica2 sensor“mote.” The source code for the modules isavailable on the web.Web Site:http://www.eecs.harvard.edu/~konrad/projects/motetrack/WBAN-AlabamaA research group in the University of Alabama inHuntsville, USA, has developed a wireless BAN ofintelligent motion sensors for computer assistedphysical rehabilitation, using 802.15.4 modules,Telos, and TinyOS. This group has also developedWBANs, with ECG, SPO2 and breathing sensors.Web Site: http://www.ece.uah.edu/~jovanov/Healthy-AimsHealthy Aims is an IP project, aimed at thedevelopment of intelligent medical implantssensors, functional electrical stimulation, humanbody motion sensors, etc. In this project a bodyarea network has been developed, enablingcommunication from implants on the body devicesto a base unit, which may be up to 3 m. away,using implantable power sources, biomaterials andRF technologies for implantable devices.Web Site: http://www.healthyaims.org/MyHeartThe European IP project MyHeart is developing aBody Area Network using smart-clothes. Itincludes electronic systems and sensors embeddedinto functional clothes. Intelligent clothes are ableto continuously monitor the vital signs of thecitizen, to make diagnosis and trend detection andreact on it. Intelligent clothes have as integratedwireless technology, Bluetooth, to link to userdevices.Web Site: http://www.hitechprojects.com/euprojects/myheart/The following pages include two summary tables(6 and 7) with the main technical characteristics ofthe BAN projects mentioned.

Description WBAN ofnon-invasivesensors TheRFtechnology isUWBNetworktechnology/ProtocolsNetwork andSensor DataRateSynchronizationRF transceiver NAMicrocontroller & OSTable 6. Body Area Networks ProjectsWBAN-ETH MobiHealth PRIMA WBAN-Alabama My Heart Ubimon Basuma Sensationcustomisable BANwith Bluetooth andGPRS/UMTSWBAN forportable/remotemonitoring andmanagement of atcardiac riskpatients (ECG,localization)WBAN ofintelligent motionsensors for computerassisted physicalrehabilitationBAN ofintelligentsensors usingsmart-clothesUWB Bluetooth IEEE 802.15.4 IEEE 802.15.4 wired BAN,BAN->PDA(Bluetooth),PDA->Server(Internet)UbiquitousMonitoringEnvironmentfor WearableandImplantableSensors"Body AreaSystem" for"UbiquitousMultimediaApplications".802.15.4 UWB-Frontendand 802.15.3(High RateWireless PAN)for MACNA 115 Kbps 250kbps 250kbps 56 kbaudps 250 kbps 20 MbpsNA NA NA NA Hardware NA NAMobi Bluetooth RC,and Bluetooth ofmobiles and Iraq(coordinator)NA CC2420 RFtransceiverNA NA NA Telos (MSP430)-TinyOSFrequency 3Ghz - 6Ghz 2,4Ghz 2,4 GHz 2.4 GHz 2.4 GHz(LAN)NANACC2420 RFtransceiverNATI MSP430 Leon2ultra low powerprocessor -TinyOS2,4 GHz UWB

WBAN-ETH MobiHealth PRIMA WBAN-Alabama My Heart Ubimon Basuma SensationPower NA NA NA NA NA Active Mode: NARequirements280uA at1MHz 2.2V ,Standby Mode:1.6uA , OffMode: 0.1uABatteries NA NA NA 2 AA batteries Ion-Lithium NA NABattery-lifetimeBatteryNA less than 2 hours NA NA 2 hours Low currentconsumption(RX:19.7mATX:17.4mA)NALAN/WANtechnologiesNA GPRS/UMTS NA GPRS Bluetooth,GPRSWi-Fi, GPRS NACurrentdeploymentstateCurrent workis focused inthe effects ofbody blockingwith UWB(1stpublication,2003)(2002-2003*)Prototypeavailable- * DelayedPrima project isclosed. The spinoffcontinues withthe R&DProject: 2004-2007PrototypingPrototypeavailable: leadsECG, 2-leadsECG strip, andSpO2---Future:ambientsensors, datamining2004-2006,Developing

6. Wireless Sensor Networks and AmIThe Ambient Intelligence paradigm is going tochange the way that the information societyservices are offered to the users. This newparadigm is based on:• The technology is peripheral and itscomplexity is hiding, in comparison, forexample, with the current access to Internetservices where the user is in the periphery andaccess to the services through computerdevices.• Services have not only to be requested by theuser but the intelligence of the system willallow the automatic provision of servicesdepending of the profile and the context of theuser.• The interaction between the services and thefinal user will be through natural interfaces,adapting to the characteristics of the finaluser.Therefore, in order to achieve services that followthis paradigm, it is necessary:• To know the context of the user. For thisreason, it is obvious the need of sensors in theenvironment and the body of the person thatacquire data dealing with the user’senvironment and state.• Distributed intelligence that allows to processthe context and user’s profile information inorder to know the conditions of the user andits environment in real time, used by the AmIservices in order to offer the appropriatedservice through the natural interfaces.• There is not limit for the AmI services, but ina great number of cases it will be necessary touse actuators that make possible to performactions in the physical environment of a user(ex., an engine that allows for opening adoor).Therefore, there is a need of transmission of datafrom sensors to the system elements where theintelligence is. The use of a mesh WSN that allowsthe transmission of data from sensors to thoseelements is, therefore, key part of an AmI system[21]. The WSN allows the easy dispersion ofsensors in the large environments in order tomonitor what happens.The same can be said about a BAN that allows themonitoring of vital sign parameters of a user.A combination of both networks is also possibleincluding mobile nodes in the body of a person thatcan be directly connected with the fixed meshnetwork in the environment.BluetoothAd-HocPersonal/HomeNetworksRFIDZigbeeWireless SensorNetworks/BANUWBAccessnetworkApplicationServerInternetMoreover, it is necessary the integration and theinteroperability of these networks with thePersonal, Local, Metropolitan and Wide arenetworks used in the “classic” applications.On another hand, AAL services need to performactions in the physical environment. The sameWSN used in the connection of sensors, allow thetransmission of commands and data to actuators inthe environment (engines, lights, etc.) and userbody (vibrator, leds, etc.)7. ConclusionsThe development of new technologies such aswireless technologies, mobile devices andembedded software is opening the doors to newapplications with the development of WirelessSensor Networks within AmI paradigm. The WSNcould collect data from the environment and thisdata could be used for the development ofintelligent systems adapted automatically to thecontext, within the paradigm of the AmbientIntelligence. The enormous potential of wirelesssensor networks opens the door to entirely newapplications.10. References[1] F.L. Lewis. “Wireless Sensor Networks”. SmartEnvironments: Technologies, Protocols, andApplications ed. D.J. Cook and S.K. Das, John Wiley,New York, 2004.[2] Edgar H. Callaway. “Wireless Sensor Networks.Architectures and Protocols”, Auebach publications,2004.[3] Benny P L Lo and Guang-Zhong Yang. “KeyTechnical Challenges and Current Implementations ofBody Sensor Networks”. 2nd International Workshop onBody Sensor Networks (BSN 2005), April 2005[4] TinyOS web site, http://www.tinyos.net/ (Last Visit:January 31st, 2005)

[5] “IEEE 802.15.4-2003”. IEEE Standard forInformation technology.http://standards.ieee.org/catalog/olis/lanman.html. (LastVisit: January 31st, 2005)[6] IEEE 802.15.4 Task Group Web Site,http://www.ieee802.org/15/pub/TG4.html. (Last Visit:January 31st, 2006)[7] L. Fernández.”Utilización de Zigbee para lamonitorización y sensorización en la salud”. Inforsalud05 (Spanish National Congress of Medical Informatics).Madrid, 2005.[8] Zigbee Alliance Web Site, http://www.zigbee.org.(Last Visit: January 31st, 2006)[9] Charles Sturman et al. “Bluetooth: Connect WithoutCables”, Prentice Hall PTR. ISBN: 0130898406.[10] “IEEE 802.15.1(tm)-2002”. IEEE Standard forInformation technology.http://standards.ieee.org/catalog/olis/lanman.html. (LastVisit: January 31st, 2005)[11] “Multi-band OFDM Physical Layer Proposal forIEEE 802.15 Task Group 3a”. IEEE P802.15 WorkingGroup for Wireless Personal Area Networks (WPANs),http://grouper.ieee.org/groups/802/15/pub/2003/Jul03/03268r2P802-15_TG3a-Multi-band-CFP-Document.pdf(Last Visit: January 31st, 2005)[12] “Wireless USB Specification 1.0”. USBImplementers Forum, May 12, 2005.[13] Julien Ryckaert, Claude Desset, Andrew Fort,Mustafa Badaroglu, et. al. “Transmitter for Low-PowerWireless Body Area Networks: Design and Evaluation”,[14] T. Zasowski, F. Althaus, M. Stäger, A. Wittneben,and G. Tröster. “UWB for Noninvasive Wireless BodyArea Networks: Channel Measurements and Results”.IEEE Conference on Ultra Wideband Systems andTechnologies, Reston, Virginia, USA, 16.-19. November2003[15] Julien Ryckaert, Claude Desset, Andrew Fort,Mustafa Badaroglu, et. al. “Ultra-Wideband Transmitterfor Low-Power Wireless Body Area Networks: Designand Evaluation”. IMEC- Belgium[16] Korhonen, I; J Parkka, and M van Gils. "Healthmonitoring in the home of the future". IEEE Eng. inMedicine and Biology Magazine. Vol 22 Nº 3 May June2003pp 66-73[17] v. Jones, R. Bults, D. Konstantas, P. AM.“Healthcare PANs: Personal Area Networks for traumacare and home care”. Fourth International Symposiumon Wireless Personal Multimedia Communications (pp.1396-1374, Denmark)[18] Thomas Norgall, Fraunhofer IIS. “Body AreaNetwork BAN - a Key Infrastructure Element for Patient-Centric Health Services”. ISO TC215/WG7/IEEE 1073Meeting, Berlin. May 2005[19] Benny P.L. Lo, Surapa Thiemjarus, Rachel Kingand Guang-Zhong Yang. “Body Sensor Network – AWireless Sensor Platform for Pervasive HealthcareMonitoring”. Department of Computing, ImperialCollege of Science, Technology and Medicine, UnitedKingdom.[20] D. Malan, T. Fulford-Jones, M. Welsh, S. Moulton.“CodeBlue: An Ad Hoc Sensor Network Infrastructurefor Emergency Medical Care”. University of Harvard,(U.S.A., 2004)[21] Monteagudo Peña, José Luis, Oscar Moreno Gil,Jorge García Pérez and Juan Reig Redondo. “Redesinalámbricas para los nuevos servicios personales de e-salud basados en tecnologías de inteligencia ambiental”.I+S nº44 (Spanish Journal of Medical Informatics).February 2004