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EL Connectivity Technologies – Part III PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cs...
EL Connectivity Technologies – Part III PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cse.iitkgp.ac.in/~smisra/ Introduction to Internet of Things 1 EL HART & Wireless HART PT N Introduction to Internet of Things 2 Introduction WirelessHART is the latest release of Highway Addressable EL Remote Transducer (HART) Protocol. HART standard was developed for networked smart field devices. cheaper and easier. PT The wireless protocol makes the implementation of HART HART encompasses the most number of field devices N incorporated in any field network. Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 3 Wireless HART enables device placements more accessible and Physical cheaper– such as the top of a reaction EL tank, inside a pipe, or at widely Data Link separated warehouses. HART Network Main difference between wired and PT unwired versions is in the physical, data link and network layers. Transport Application Wired HART lacks a network layer. N Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 4 HART Physical Layer Derived from IEEE 802.15.4 protocol. EL It operates only in the 2.4 GHz ISM band. Employs and exploits 15 channels of the band to increase reliability. PT N Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 5 HART Data Link Layer Collision free and deterministic communication achieved by means of super‐frames and TDMA. EL Super‐frames consist of grouped 10ms wide timeslots. Super‐frames control the timing of transmission to ensure collision free and reliable communication. PT This layer incorporates channel hopping and channel blacklisting to increase reliability and security. Channel blacklisting identifies channels consistently affected by N interference and removes them from use. Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 6 HART Network & Transport Layers Cooperatively handle various types of traffic, routing, session EL creation, and security. WirelessHART relies on Mesh networking for its communication, and each device is primed to forward packets from every other devices. PT Each device is armed with an updated network graph (i.e., updated topology) to handle routing. Network layer (HART)=Network + Transport + Session layers (OSI) N Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 7 HART Application Layer Handles communication between gateways and devices via a EL series of command and response messages. Responsible for extracting commands from a message, executing it and generating responses. PT This layer is seamless and does not differentiate between wireless and wired versions of HART. N Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 8 HART Congestion Control Restricted to 2.4Ghz ISM band with channel 26 removed, due to its restricted usage in certain areas. EL Interference‐prone channels avoided by using channel switching post every transmission. Transmissions synchronized using 10ms slots. PT During each slot, all available channels can be utilized by the various nodes in the network allowing for the propagation of 15 packets through the network at a time, which also minimizes the risk of N collisions. Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 9 WirelessHART Network Manager The network manager supervises each node in the network and EL guides them on when and where to send packets. Allows for collision‐free and timely delivery of packets between a source and destination. The network manager updates information about neighbors, signal PT strength, and information needing delivery or receipt. Decides who will send, who will listen, and at what frequency is each time‐slot. Handles code‐based network security and prevents unauthorized N nodes from joining the network. Introduction to Internet of Things 10 WirelessHART vs. ZigBee A WirelessHART node hops after every message, changing EL channels every time it sends a packet. ZigBee does not feature hopping at all, and only hops when the entire network hops. At the MAC layer, WirelessHART utilizes time division multiple with collision detection PT access (TDMA), allotting individual time slots for each transmission. ZigBee applies carrier sense multiple access avoidance (CSMA/CD). CSMA/CA N Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 11 WirelessHART represents a true mesh network, where each node is capable of serving as a router so that, if one node goes down, another can replace it, ensuring packet delivery. EL ZigBee utilizes a tree topology, which makes nodes along the trunk critical. WirelessHART devices are all back compatible, allowing for PT the integration of legacy devices as well as new ones. ZigBee devices share the same basis for their physical layers, but ZigBee, ZigBee Pro, ZigBee RF4CE, and ZigBee IP are otherwise incompatible with each other N Source: A. Feng, “WirelessHART‐ Made Easy”, AwiaTech Blog (Online), Nov. 2011 Introduction to Internet of Things 12 EL NFC PT N Introduction to Internet of Things 13 Introduction Near field communication, or NFC for EL short, is an offshoot of radio‐frequency Type B identification (RFID). NFC is designed for use by devices within Type A FeliCa close proximity to each other. All NFC types are similar but PT communicate in slightly different ways. NFC N FeliCa is commonly found in Japan. Source: “How NFC Works”, NFC (Online) Introduction to Internet of Things 14 NFC Types Passive devices contain information EL which is readable by other devices, Smartphone however it cannot read information itself. NFC tags found in supermarket products Active Passive are examples of passive NFC. PT Active devices are able to collect as well NFC Tags as transmit information. Smartphones are a good example of N active devices. Source: “How NFC Works”, NFC (Online) Introduction to Internet of Things 15 Working Principle Works on the principle of magnetic induction. EL A reader emits a small electric current which creates a magnetic field that in turn bridges the physical space between the devices. The generated field is received by a similar coil in the client device where it is turned back into electrical impulses to communicate information. PT data such as identification number status information or any other ‘Passive’ NFC tags use the energy from the reader to encode their response while ‘active’ or ‘peer‐to‐peer’ tags have their own power N source. Source: “Inside NFC: how near field communication works”, APC (Online), Aug. 2011 Introduction to Internet of Things 16 EL PT N Introduction to Internet of Things 17 NFC Specifications NFC's data‐transmission frequency is 13.56MHz. EL NFC can transmit data at a rate of either 106, 212 or 424 Kbps (kilobits per second). Tags typically store between 96 and 512 bytes of data. PT Communication range is less than 20cms. N Source: “Inside NFC: how near field communication works”, APC (Online), Aug. 2011 Introduction to Internet of Things 18 Modes of Operation Peer‐to‐peer EL Lets two smartphones swap data One active device picks up info from a Read/Write Card emulation PT passive one NFC device can be used like a N contactless credit card Source: M. Egan, “What is NFC? Uses of NFC | How to use NFC on your smartphone”, TechAdvisor (Online), May 2015 Introduction to Internet of Things 19 NFC Applications Smartphone based payments. EL Parcel tracking. Information tags in posters and advertisements. PT Computer game synchronized toys. Low‐power home automation systems. N Introduction to Internet of Things 20 EL PT N Introduction to Internet of Things 21 EL Connectivity Technologies – Part IV PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cse.iitkgp.ac.in/~smisra/ Introduction to Internet of Things 1 EL Bluetooth PT N Introduction to Internet of Things 2 Introduction Bluetooth wireless technology is a short range EL communications technology. Intended for replacing cables connecting portable units Maintains high levels of security. PT Bluetooth technology is based on Ad‐hoc technology also known as Ad‐hoc Piconets. N Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 3 Features Bluetooth technology operates in the unlicensed industrial, EL scientific and medical (ISM) band at 2.4 to 2.485 GHZ. Uses spread spectrum hopping, full‐duplex signal at a nominal rate of 1600 hops/sec. PT Bluetooth supports 1Mbps data rate for version 1.2 and 3Mbps data rate for Version 2.0 combined with Error Data Rate. N Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 4 Features Bluetooth operating range depends on the device: EL Class 3 radios have a range of up to 1 meter or 3 feet Class 2 radios are most commonly found in mobile devices have a range of 10 meters or 30 feet PT Class 1 radios are used primarily in industrial use cases have a range of 100 meters or 300 feet. N Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 5 Connection Establishment EL Inquiry Inquiry run by one Bluetooth device to try to discover other devices near it. Paging Process of forming a connection between two PT Connection Bluetooth devices. A device either actively participates in the network or enters a low‐power sleep mode. N Source: “Bluetooth Basics”, Tutorials, Sparkfun.com (Online) Introduction to Internet of Things 6 Modes Active Sniff Hold Park EL Actively transmitting or PT Sleeps and only listens for transmissions at a Power‐saving mode where a device sleeps for a Slave will become inactive until the master tells it to N receiving data. set interval. defined period and wake back up. then returns back Source: “Bluetooth Basics”, Tutorials, Sparkfun.com (Online) to active mode. Introduction to Internet of Things 7 Protocol Stack EL PT N Introduction to Internet of Things 8 Baseband Physical layer of the Bluetooth. EL Manages physical channels and links. Other services include: Error correction Data whitening Hop selection Bluetooth security PT Manages asynchronous and synchronous links. N Handles packets, paging and inquiry. Source: “Bluetooth”, Wikipedia (Online) Introduction to Internet of Things 9 L2CAP The Logical Link Control and Adaptation Protocol (L2CAP). EL Layered over the Baseband Protocol and resides in the data link layer. Used to multiplex multiple logical connections between two devices. Provides connection‐oriented and connectionless data services to upper layer protocols. Provides: PT Protocol multiplexing capability Segmentation and reassembly operation N Group abstractions Source: “Bluetooth”, Wikipedia (Online) Introduction to Internet of Things 10 RFComm Radio Frequency Communications (RFCOMM). It is a cable replacement protocol used for generating a virtual serial EL data stream. RFCOMM provides for binary data transport. Emulates EIA‐232 (formerly RS‐232) control signals over the PT Bluetooth baseband layer, i.e. it is a serial port emulation. RFCOMM provides a simple reliable data stream to the user, similar to TCP. Supports up to 60 simultaneous connections between two BT N devices. Source: “Bluetooth”, Wikipedia (Online) Introduction to Internet of Things 11 Service Discovery Protocol (SDP) Enables applications to discover available services and their EL features. Addresses the unique characteristics of the Bluetooth environment such as, dynamic changes in the quality of PT services in RF proximity of devices in motion. Can function over a reliable packet transfer protocol. Uses a request/response model. N Source: “Bluetooth”, Wikipedia (Online) Introduction to Internet of Things 12 Piconets Bluetooth enabled electronic devices connect and communicate wirelessly through short range networks known EL as Piconets. Bluetooth devices exist in small ad‐hoc configurations with the ability to act either as master or slave. to switch their roles. PT Provisions are in place, which allow for a master and a slave The simplest configuration is a point to point configuration N with one master and one slave. Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 13 When more than two Bluetooth devices communicate with one another, it is called a PICONET. A Piconet can contain up to seven slaves clustered around a EL single master. The device that initializes establishment of the Piconet becomes the master. PT The master is responsible for transmission control by dividing the network into a series of time slots amongst the network N members, as a part of time division multiplexing scheme. Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 14 EL PT N Introduction to Internet of Things 15 Features of Piconet Within a Piconet, the clock and unique 48‐bit address of master EL determines the timing of various devices and the frequency hopping sequence of individual devices. Each Piconet device supports 7 simultaneous connections to other devices. PT Each device can communicate with several piconets simultaneously. Piconets are established dynamically and automatically as N Bluetooth enabled devices enter and leave piconets. Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 16 There is no direct connection between the slaves. All connections are either master‐to‐slave or slave‐to‐master. EL Slaves are allowed to transmit once these have been polled by the master. Transmission starts in the slave‐to‐master time slot PT immediately following a polling packet from the master. A device can be a member of two or more Piconets. N Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 17 A device can be a slave in one Piconet and master in another. It however cannot be a master in more than once Piconets. Devices in adjacent Piconets provide a bridge to support EL inner‐Piconet connections, allowing assemblies of linked Piconets to form a physically extensible communication infrastructure known as Scatternet. PT N Source: “Wireless Communication ‐ Bluetooth”, Tutorials Point (Online) Introduction to Internet of Things 18 Applications Audio players EL Home automation Smartphones Toys PT Hands free headphones Sensor networks N Introduction to Internet of Things 19 EL PT N Introduction to Internet of Things 20 EL Connectivity Technologies – Part V PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cse.iitkgp.ac.in/~smisra/ Introduction to Internet of Things 1 EL Z Wave PT N Introduction to Internet of Things 2 Introduction Zwave (or Z wave or Z‐wave) is a protocol for communication EL among devices used for home automation. It uses RF for signaling and control. Operating frequency is 908.42 MHz in the US & 868.42 MHz in Europe. PT Mesh network topology is the main mode of operation, and N can support 232 nodes in a network. Source: “What is Z‐Wave?”, Smart Home (Online) Introduction to Internet of Things 3 Zwave Global Operating Frequency Frequency in MHz Used in EL 865.2 India 868.1 Malaysia 868.42 ; 869.85 Europe 868.4 China, Korea 869.0 PT 908.4 ; 916.0 915.0 ‐ 926.0 919.8 921.4 ; 919.8 Russia USA Israel Hong Kong Australia, New Zealand N 922.0 ‐ 926.0 Japan Source: “Z‐Wave”, Wikipedia (Online) Introduction to Internet of Things 4 Zwave utilizes GFSK modulation and Manchester channel encoding. A central network controller device sets‐up and manages a EL Zwave network. Each logical Zwave network has 1 Home (Network) ID and multiple node IDs for the devices in it. PT Nodes with different Home IDs cannot communicate with each other. Network ID length=4 Bytes, Node ID length=1 Byte. N Source: “What is Z‐Wave?”, Smart Home (Online) Introduction to Internet of Things 5 GFSK Gaussian Frequency Shift Keying. EL Baseband pulses are passed through a Gaussian filter prior to modulation. Filtering operation smoothens the pulses consisting of PT streams of ‐1 and 1, and is known as Pulse shaping. Pulse shaping limits the modulated spectrum width. N Introduction to Internet of Things 6 EL PT N Introduction to Internet of Things 7 Uses source routed network mesh topology using 1 primary controller. Devices communicate with one another when in range. EL When devices are not in range, messages are routed though different nodes to bypass obstructions created by household appliances or layout. called Healing. PT This process of bypassing radio dead‐spots is done using a message As Zwave uses a source routed static network, mobile devices are N excluded from the network and only static devices are considered. Source: “What is Z‐Wave?”, Smart Home (Online) Introduction to Internet of Things 8 EL PT N Introduction to Internet of Things 9 Zwave vs. Zigbee Zwave Zigbee EL User friendly and provides a Requires so little power that simple system that users can set devices can last up to seven years up themselves. on one set of batteries. Ideal for someone with a basic understanding of technology who wants to keep their home automation secure, efficient, PT Ideal for technology experts who want a system they can customize with their preferences and install themselves. N simple to use, and easy to maintain. Source: Sarah Brown, “ZigBee vs. Z‐Wave Review: What’s the Best Option for You?”, The SafeWise Report (Online), Mar 2016 Introduction to Internet of Things 10 Zwave vs. Zigbee Zwave Zigbee EL Expensive. Cheaper than Zwave. Nine out of ten leading ZigBee Alliance consists of security and communication companies in the U.S. use Z‐ Wave in their smart home solutions PT nearly 400 member organizations that use, develop, and improve ZigBee’s open‐standard N wireless connection Source: Sarah Brown, “ZigBee vs. Z‐Wave Review: What’s the Best Option for You?”, The SafeWise Report (Online), Mar 2016 Introduction to Internet of Things 11 EL ISA 100.11A PT N Introduction to Internet of Things 12 Introduction International Society of Automation. EL Designed mainly for large scale industrial complexes and plants. More than 1 billion devices use ISA 100.11A application layers. PT ISA 100.11A is designed to support native and tunneled Various transport services, including ‘reliable,’ ‘best effort,’ N ‘real‐time’ are offered. Source: “The ISA 100 Standards : Overview and Status” ISA, 2008 Introduction to Internet of Things 13 Network and transport layers are based on TCP or UDP / IPv6. Data link layer supports mesh routing and Frequency hopping. Physical and MAC layers are based on IEEE 802.15.4 EL Topologies allowed are: Star/tree Mesh Permitted networks include: Radio link ISA over Ethernet PT N Field buses Source: Cambridge Whitepaper, http://portal.etsi.org/docbox/Workshop/2008/200812_WIRELESSFACTORY/CAMBRIDGE_WHITTAKER.pdf Introduction to Internet of Things 14 Application Support Layer delivers communications services to user and management processes. It can pass objects (methods, attributes) natively within the EL ISA 100.11A protocol. A tunneling mode is available to allow legacy data through the ISA100.11A network. PT N Source: Tim Whittaker , “What do we expect from Wireless in the Factory?”Cambridge Whitepaper, Cambridge Consultants, 2008 Introduction to Internet of Things 15 RD=routing device NRD=Non‐ EL routing device H=Handheld device B=backbone device PT N Source: Tim Whittaker , “What do we expect from Wireless in the Factory?”Cambridge Whitepaper, Cambridge Consultants, 2008 Introduction to Internet of Things 16 Features Flexibility EL Support for multiple protocols Use of open standards PT Support for multiple applications Reliability (error detection, channel hopping) Determinism (TDMA, QoS support) N Security Introduction to Internet of Things 17 Security Security is fully built‐in to the standard. EL Authentication and confidentiality services are independently available. A network security manager manages and distributes keys. PT Twin data security steps in each node: Data link layer encrypts each hop. N Transport layer secures peer‐to‐peer communications. Source: Tim Whittaker , “What do we expect from Wireless in the Factory?”Cambridge Whitepaper, Cambridge Consultants, 2008 Introduction to Internet of Things 18 ISA100.11A Usage Classes Category Class Application Description EL Safety 0 Emergency action Always critical 1 Closed loop regulatory Often critical control Control 2 Closed loop Usually non‐critical Monitoring 3 4 PT supervisory control Open loop control Alerting Human‐in‐the‐loop Short term operational consequence N 5 Logging/ Downloading No immediate operational consequence Introduction to Internet of Things 19 EL PT N Introduction to Internet of Things 20 EL Sensor Networks – Part I PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cse.iitkgp.ac.in/~smisra/ Introduction to Internet of Things 1 Wireless Sensor Networks (WSNs) Consists of a large number of sensor nodes, densely deployed over an area. EL Sensor nodes are capable of collaborating with one another and measuring the condition of their surrounding environments (i.e. Light, temperature, sound, vibration). PT The sensed measurements are then transformed into digital signals and processed to reveal some properties of the phenomena around sensors. Due to the fact that the sensor nodes in WSNs have short radio transmission range, intermediate nodes act as relay nodes to transmit data towards the sink N node using a multi‐hop path. Introduction to Internet of Things 2 Multi-hop Path in WSNs EL PT N Introduction to Internet of Things 3 Basic Components of a Sensor Node EL PT N Introduction to Internet of Things 4 Sensor Nodes Multifunctional EL The number of sensor nodes used depends on the application type. Short transmission ranges PT Have OS (e.g., TinyOS). Battery Powered – Have limited life. N Image source: Wikimedia Commons Introduction to Internet of Things 5 Constraints on Sensor Nodes Small size, typically less than a cubic cm. EL Must consume extremely low power Operate in an unattended manner in a highly dense area. PT Should have low production cost and be dispensable Be autonomous N Be adaptive to the environment Introduction to Internet of Things 6 Applications Temperature measurement EL Humidity level Lighting condition Air pressure Soil makeup Noise level PT N a) Soil sensor node b) Temperature Flux sensor node c) Weather sensor node Vibration Image source: Wikimedia Commons Introduction to Internet of Things 7 Single Source Single Object Detection H 17 11 EL Source Obj 18 5 17 4 12 H 13 Source PT 2 3 7 6 8 10 15 16 N Sink 9 14 H Human User 1 Introduction to Internet of Things 8 Single Source Multiple Object Detection B H 11 Source Obj EL 17 H 17 17 V V 18 17 B 5 4 12 13 Source Sink H Human PT 2 3 7 6 8 10 15 16 N 9 14 V Vehicle B Building User 1 Introduction to Internet of Things 9 Multiple Source Single Object Detection 2 Source Obj EL 1 1 V 2 V 17 11 4 V V 15 V 4 15 17 V 18 5 12 Source PT 6 3 13 7 8 10 16 N Sink V Vehicle 9 14 User Introduction to Internet of Things 10 Multiple Source Multiple Object Detection 1 9 Source Obj EL H 1 H B 1 B 4 11 4 B 17 9 H 6 18 17 V 5 H 12 4 Source Sink H Human 2 PT 3 13 7 8 10 15 16 2 V V N V Vehicle B Building 14 User Introduction to Internet of Things 11 H 6 B 2 15 EL 9 17 11 Source Obj 6 H 1 V 18 2 B 5 4 12 Source Sink H Human V 1 PT 3 13 7 8 10 16 N V Vehicle B Building 14 User Introduction to Internet of Things 12 Challenges Scalability Providing acceptable levels of service in the presence of large number EL of nodes. 1 Typically, throughput decreases at a rate of N , N = number of nodes. Quality of service PT Offering guarantees in terms of bandwidth, delay, jitter, packet loss probability. N Limited bandwidth, unpredictable changes in RF channel characteristics. Introduction to Internet of Things 13 Challenges (contd.) Energy efficiency EL Nodes have limited battery power Nodes need to cooperate with other nodes for relaying their information. Security Open medium. PT Nodes prone to malicious attacks, infiltration, eavesdropping, interference. N Introduction to Internet of Things 14 Sensor Web EL PT N Source: X. Chu and R. Buyya, “Service Oriented Sensor Web”, Sensor Networks and Configuration, Springer, 2007, pp. 51‐74. Introduction to Internet of Things 15 Sensor Web WNS: Web Notification Services EL SCS: Sensor Collection Services SPS: Sensor Planning Services PT SensorML: Sensor Modeling language N Source: X. Chu and R. Buyya, “Service Oriented Sensor Web”, Sensor Networks and Configuration, Springer, 2007, pp. 51‐74. Introduction to Internet of Things 16 Sensor Web Entanglement Observations & measurements (O&M) EL Sensor model language (sensorml) Transducer model language (transducerml or TML) PT Sensor observations service (SOS) Sensor planning service (SPS) Sensor alert service (SAS) N Web notification services (WNS) Introduction to Internet of Things 17 Cooperation in Wireless Ad Hoc and Sensor Networks Nodes communicate with other nodes with the help of EL intermediate nodes. The intermediate nodes act as relays. Wireless nodes are energy‐constrained. PT Nodes may or may not cooperate. N Introduction to Internet of Things 18 Cooperation in Wireless Ad Hoc and Sensor Networks Two extremities: EL Total cooperation: if all relay requests are accepted, nodes will quickly exhaust limited energy. Total non‐cooperation: if no relay requests are accepted, the network throughput will go down rapidly. Issues: PT Selfishness, self‐interests, etc. Symbiotic dependence N Tradeoff: individual node’s lifetime vs. Throughput. Introduction to Internet of Things 19 Security Challenges in Cooperation Open, shared radio medium by the nodes, which dynamically EL change positions. No centralized network management or certification authority. Existence of malicious nodes. Nodes prone to attacks, infiltration, eavesdropping, interference. PT Nodes can be captured, compromised, false routing information can be sent – paralyzing the whole network. The cooperating node or the node being cooperated might be N victimized. Introduction to Internet of Things 20 EL PT N Introduction to Internet of Things 21 EL Sensor Networks – Part II PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cse.iitkgp.ac.in/~smisra/ Introduction to Internet of Things 1 Node Behavior in WSNs Node EL Normal Misbehaving PT Unintentional Intentional N Failed Badly Failed Selfish Malicious Introduction to Internet of Things 2 Node Behavior in WSNs (contd.) Normal nodes work perfectly in ideal environmental EL conditions Failed nodes are simply those that are unable to perform an operation; this could be because of power failure and PT environmental events. Badly failed nodes exhibit features of failed nodes but they can also send false routing messages which are a threat to the N integrity of the network. Introduction to Internet of Things 3 Node Behavior in WSNs (contd.) Selfish nodes are typified by their unwillingness to cooperate, EL as the protocol requires whenever there is a personal cost involved. Packet dropping is the main attack by selfish nodes. Malicious nodes aim to deliberately disrupt the correct PT operation of the routing protocol, denying network service if possible. N Introduction to Internet of Things 4 Dynamic Misbehavior: Dumb Behavior Detection of such temporary misbehavior in order to preserve normal EL functioning of the network – coinage and discovery of dumb behavior In the presence of adverse environmental conditions (high temperature, rainfall, and fog) the communication range shrinks A sensor node can sense its surroundings but is unable to transmit the sensed data PT With the resumption of favorable environmental conditions, dumb nodes work normally Dumb behavior is temporal in nature (as it is dependent on the effects of N environmental conditions) Introduction to Internet of Things 5 Detection and Connectivity Re-establishment The presence of dumb nodes impedes the overall network performance EL Detection, and, subsequently, the re‐establishment of network connectivity is crucial The sensed information can only be utilized if the connectivity between each dumb node with other nodes in the network could be re‐established PT Before restoration of network connectivity, it is essential to detect the dumb nodes in the network. CoRD and CoRAD are two popular schemes that re‐establish the N connectivity between dumb nodes with others. Introduction to Internet of Things 6 Event-Aware Topology Management in Wireless Sensor Networks Timely detection of an event of interest EL Monitoring the event Disseminating event‐data to the sink PT Adapting with the changes of event state Event location Event area N Event duration Source: S. N. Das, S. Misra, M. S. Obaidat, "Event‐Aware Topology Management in Wireless Sensor Networks", Proceedings of Ubiquitous Information Technologies and Applications (CUTE 2013), Springer Lecture Notes in Electrical Engineering, Vol. 214, 2013, pp. 679‐687 Introduction to Internet of Things 7 Information Theoretic Self-Management of Wireless Sensor Networks A WSN is deployed with the intention of acquiring information EL The sensed information are transmitted in the form of packets Information theoretic self‐management (INTSEM) controls the transmission rate of a node by adjusting a node’s sleep time Benefits PT Reduce consumption of transmission energy of transmitters N Reduce consumption of receiving energy of relay nodes S. N. Das and S. Misra, "Information theoretic self‐management of Wireless Sensor Networks", Proceedings of NCC 2013. Introduction to Internet of Things 8 General Framework of InTSeM EL PT N Introduction to Internet of Things 9 Social Sensing in WSNs Social Sensing‐based Duty Cycle Management for Monitoring EL Rare Events in Wireless Sensor Networks WSNs are energy‐constrained Scenario: PT Event monitoring using WSNs WSNs suffer from ineffective sensing for rare events Event monitoring or sensing, even if there is no event to monitor or sense N Example: Submarine monitoring in underwater surveillance Introduction to Internet of Things 10 Social Sensing in WSNs (contd.) Possible Solution Approach: Duty‐cycle management EL Limitations: SMAC [Ye et al., INFOCOM, 2002] Do not distinguish the 11rare DutyCon [Wang et al., ACM TSN, 2013] events from regular events PW‐MAC [Tang et al., INFOCOM, 2011] PT Ineffective wakeup and sensing under rare event monitoring scenario N Source: S. Misra, S. Mishra, M. Khatua, "Social Sensing‐based Duty Cycle Management for Monitoring Rare Events in Wireless Sensor Networks", IET Wireless Sensor Systems Introduction to Internet of Things Social Sensing in WSNs (contd.) Challenges: EL Distinguish rare events and regular events Adapt the duty‐cycle with the event occurrence probability. Contribution: PT Probabilistic duty cycle (PDC) in WSNs Accumulates information from the social media to identify the occurrence possibility of rare events N Adjusts the duty cycles of sensor nodes using weak estimation learning automata Introduction to Internet of Things 12 EL PT N Introduction to Internet of Things 13 Applications of WSNs: Mines Fire Monitoring and Alarm System for Underground Coal EL Mines Bord‐and‐Pillar Panel Using Wireless Sensor Networks WSN‐based simulation model for building a fire monitoring and alarm (FMA) system for Bord & Pillar coal mine. PT The fire monitoring system has been designed specifically for Bord & Pillar based mines N Source: S. Bhattacharjee, P. Roy, S. Ghosh, S. Misra, M. S. Obaidat, "Fire Monitoring and Alarm System for Underground Coal Mines Bord‐and‐Pillar Panel Using Wireless Sensor Networks", Journal of Systems and Software (Elsevier), Vol. 85, No. 3, March 2012, pp. 571‐581. Introduction to Internet of Things 14 Applications of WSNs: Mines (contd.) It is not only capable of providing EL real‐time monitoring and alarm in case of a fire, but also capable of providing the exact fire location and spreading direction by continuously gathering, analysing, and storing real time information PT N Source: S. Bhattacharjee, P. Roy, S. Ghosh, S. Misra, M. S. Obaidat, "Fire Monitoring and Alarm System for Underground Coal Mines Bord‐and‐Pillar Panel Using Wireless Sensor Networks", Journal of Systems and Software (Elsevier), Vol. 85, No. 3, March 2012, pp. 571‐581. Introduction to Internet of Things 15 Applications of WSNs: Healthcare Wireless Body Area Networks EL Wireless body area networks (WBANs) have recently gained popularity due to their ability in providing innovative, cost‐effective, and user‐friendly solution for continuous monitoring of vital physiological PT parameters of patients. Monitoring chronic and serious diseases such as cardiovascular diseases and diabetes. Could be deployed in elderly persons for monitoring N their daily activities. Introduction to Internet of Things 16 Applications of WSNs: Healthcare (contd.) Social Choice Considerations in Cloud‐Assisted WBAN Architecture EL A proper aggregation function necessarily needs to be “fair", so that none of the eligible elements are ignored unjustly. In a post‐disaster environment, it is required to monitor patients' health conditions remotely. PT This includes ambulatory healthcare services where the health status of a patient is examined continuously over time, while the patient is being moved to the emergency healthcare center. N Source: S. Misra, S. Chatterjee, "Social Choice Considerations in Cloud‐Assisted WBAN Architecture for Post‐Disaster Healthcare: Data Aggregation and Channelization",Information Sciences (Elsevier), 2016 Introduction to Internet of Things 17 Applications of WSNs: Healthcare (contd.) The work focuses on the formation of pseudo‐clusters so that EL the aggregation is not biased towards the leader nodes. Data aggregation among the LDPUs is done in a “fair" manner following the Theory of Social Choice. PT Aggregation is performed at mobile aggregation centers, thereby increasing the scalability of the system. After the aggregation of data, the gateways are allocated dynamically. N Source: S. Misra, S. Chatterjee, "Social Choice Considerations in Cloud‐Assisted WBAN Architecture for Post‐Disaster Healthcare: Data Aggregation and Channelization",Information Sciences (Elsevier), 2016 Introduction to Internet of Things 18 Applications of WSNs: Healthcare (contd.) Payload tuning mechanism for WBANs EL In addition to the actual health condition, there exists indirect influence of external parameters such as – age, height, weight, and sex on health parameters. In crisp set theory, we are unable to interpret how much ‘low’, ‘moderate’, PT or ‘high’, a particular health parameter is. Exclusion of the important external parameters while assessing health and the usage of traditional crisp set theory may result into inefficient decision N making. Source: S. Moulik, S. Misra, C. Chakraborty, M. S. Obaidat, "Prioritized Payload Tuning Mechanism for Wireless Body Area Network‐Based Healthcare Systems", Proceedings of IEEE GLOBECOM, 2014 Introduction to Internet of Things 19 Applications of WSNs: Healthcare (contd.) Challenge is to design a dynamic decision making model that EL can optimize the energy consumption of each physiological sensor Fuzzy inference system (FIS) and markov decision process PT (MDP) are used to optimize energy consumption N Source: S. Moulik, S. Misra, C. Chakraborty, M. S. Obaidat, "Prioritized Payload Tuning Mechanism for Wireless Body Area Network‐Based Healthcare Systems", Proceedings of IEEE GLOBECOM, 2014 Introduction to Internet of Things 20 Applications of WSNs: Healthcare (contd.) Priority‐Based Time‐Slot Allocation in WBANs EL In medical emergency situations, it is important to discriminate the WBANs transmitting critical heath data from the ones transmitting data of regular importance. PT Existing frequency division‐based transmission in a multisource‐ single‐sink network results in flooding of the sink’s receiver buffer. This leads to packet loss and consequent retransmission of the N regenerated packets. Source: S. Misra, S. Sarkar, "Priority‐Based Time‐Slot Allocation in Wireless Body Area Networks During Medical Emergency Situations: An Evolutionary Game Theoretic Perspective", IEEE Journal of Biomedical and Health Informatics, 2014 Introduction to Internet of Things 21 Applications of WSNs: Healthcare (contd.) Transmission priority of an local data processing unit (LDPU) is indifferent to the criticality of the health data that is being transmitted by the LDPU. EL Based on LDPU‐properties, such as the criticality of health data, energy dissipation factor, and time elapsed since last successful transmission, a fitness parameter is formulated which is a relative measure of node‐ importance. PT The priority‐based allocation of time slots (PATS) algorithm allows the LDPUs to choose their strategies based on their fitness. LDPUs with higher fitness are given higher preference, while ensuring N minimum waiting time between successive transmission of data‐packets. Source: S. Misra, S. Sarkar, "Priority‐Based Time‐Slot Allocation in Wireless Body Area Networks During Medical Emergency Situations: An Evolutionary Game Theoretic Perspective", IEEE Journal of Biomedical and Health Informatics, 2014 Introduction to Internet of Things 22 EL PT N Introduction to Internet of Things 23
