Connectivity Technologies – Part II PDF

EL Connectivity Technologies – Part II PT Dr. Sudip Misra Associate Professor Department of Computer Science and Engineering IIT KHARAGPUR N Email: [email protected] Website: http://cse.iitk...

EL Connectivity Technologies – 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  EL 6LoWPAN PT N Introduction to Internet of Things 2  Introduction  Low‐power Wireless Personal Area Networks over IPv6. EL  Allows for the smallest devices with limited processing ability to transmit information wirelessly using an Internet protocol.  Allows low‐power devices to connect to the Internet. PT  Created by the Internet Engineering Task Force (IETF) ‐ RFC 5933 and RFC 4919. N Source: T. Winter, P. Thubert, A. Brandt, J. Hui, R. Kelsey, P. Levis, K. Pister, R. Struik , JP. Vasseur, R. Alexander, “RPL: IPv6 Routing Protocol for Low‐Power and Lossy Networks”, IETF, Standards Track, Mar. 2012 Introduction to Internet of Things 3 Features of 6LoWPANs  Allows IEEE 802.15.4 radios to carry 128‐bit addresses of EL Internet Protocol version 6 (IPv6).  Header compression and address translation techniques allow the IEEE 802.15.4 radios to access the Internet. PT  IPv6 packets compressed and reformatted to fit the IEEE 802.15.4 packet format.  Uses include IoT, Smart grid, and M2M applications. N Introduction to Internet of Things 4 Addressing in 6LoWPAN 64‐bit addresses: globally Addressing EL unique 16 bit addresses: PAN specific; 64‐bit assigned by PAN coordinator Extended 16‐bit PT IPv6 multicast not supported by 802.15.4 IPv6 packets carried as link N Short layer broadcast frames Introduction to Internet of Things 6LowPAN Packet Format 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 Length Flags DSN IEEE 802.15.4 EL PAN ID Destination (64 bit) Source (64 bit) Ver PT Traffic Class Payload Length Flow Label Next Header Hop Limit IPv6 Source Address (128 bit) N Destination Length (128 bit) Introduction to Internet of Things  Header Type: Dispatch Header 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 EL 0 1 Dispatch Type Specific Header Dispatch: Initiates communication 0,1: Identifier for Dispatch Type Dispatch: 6 bits PT Identifies the next header type N Type Specific Header: Determined by Dispatch header Introduction to Internet of Things  Header Type: Mesh Addressing Header 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 EL 1 0 V F Hops Left Originator Address Final Address 1,0: ID for Mesh Addressing Header address PT V: ‘0’ if originator is 64‐bit extended address, ‘1’ if 16‐bit F: ‘0’ if destination is 64‐bit addr., ‘1’ if 16‐bit addr. N Hops Left: decremented by each node before sending to next hop Introduction to Internet of Things  Header Type: Fragmentation Header 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 EL 1 1 0 0 Datagram Size Datagram Tag (a) First Fragment 1 2 1 1 0 0 3 4 5 6 Datagram Offset 7 8 PT 1 2 3 4 Datagram Size 5 6 7 8 1 2 3 4 5 6 7 8 1 2 Datagram Tag 3 4 5 6 7 8 N (b) Subsequent Fragment Introduction to Internet of Things 6LoWPAN Routing Considerations  Mesh routing within EL the PAN space.  Routing between IPv6 and the PAN domain use:  LOADng PT  Routing protocols in N  RPL Introduction to Internet of Things 10  LOADng Routing  Derived from AODV and extended for use in IoT. EL  Basic operations of LOADng include:  Generation of Route Requests (RREQs) by a LOADng Router (originator) for discovering a route to a destination,  Forwarding of such RREQs until they reach the destination LOADng Router, PT  Generation of Route Replies (RREPs) upon receipt of an RREQ by the indicated destination, and unicast hop‐by‐hop forwarding of these RREPs towards the originator. N Source: Clausen, T.; Colin de Verdiere, A.; Yi, J.; Niktash, A.; Igarashi, Y.; Satoh, H.; Herberg, U.; Lavenu, C. et al. (January 2016). The Lightweight On‐demand Ad hoc Distance‐vector Routing Protocol ‐ Next Generation (LOADng). IETF. I‐D draft‐clausen‐lln‐loadng‐14 Introduction to Internet of Things 11   If a route is detected to be broken, a Route Error (RERR) message is returned to the originator of that data packet to inform the originator about the route breakage. EL  Optimized flooding is supported, reducing the overhead incurred by RREQ generation and flooding.  Only the destination is permitted to respond to an RREQ.  Intermediate LOADng Routers are explicitly prohibited from sought destination. PT responding to RREQs, even if they may have active routes to the  RREQ/RREP messages generated by a given LOADng Router share a N single unique, monotonically increasing sequence number. Source: Clausen, T.; Colin de Verdiere, A.; Yi, J.; Niktash, A.; Igarashi, Y.; Satoh, H.; Herberg, U.; Lavenu, C. et al. (January 2016). The Lightweight On‐demand Ad hoc Distance‐vector Routing Protocol ‐ Next Generation (LOADng). IETF. I‐D draft‐clausen‐lln‐loadng‐14 Introduction to Internet of Things 12  RPL Routing  Distance Vector IPv6 routing protocol for lossy and low power networks. EL  Maintains routing topology using low rate beaconing.  Beaconing rate increases on detecting inconsistencies (e.g. node/link in a route is down). PT  Routing information included in the datagram itself.  Proactive: Maintaining routing topology. N  Reactive: Resolving routing inconsistencies. Source: T. Winter, P. Thubert, A. Brandt, J. Hui, R. Kelsey, P. Levis, K. Pister, R. Struik , JP. Vasseur, R. Alexander, “RPL: IPv6 Routing Protocol for Low‐Power and Lossy Networks”, IETF, Standards Track, Mar. 2012 Introduction to Internet of Things 13   RPL separates packet processing and forwarding from the routing optimization objective, which helps in Low power Lossy Networks (LLN). EL  RPL supports message confidentiality and integrity.  Supports Data‐Path Validation and Loop Detection  minimizing energy  minimizing latency PT  Routing optimization objectives include N  satisfying constraints (w.r.t node power, bandwidth, etc.) Source: T. Winter, P. Thubert, A. Brandt, J. Hui, R. Kelsey, P. Levis, K. Pister, R. Struik , JP. Vasseur, R. Alexander, “RPL: IPv6 Routing Protocol for Low‐Power and Lossy Networks”, IETF, Standards Track, Mar. 2012 Introduction to Internet of Things 14   RPL operations require bidirectional links.  In some LLN scenarios, those links may exhibit asymmetric properties. EL  It is required that the reachability of a router be verified before the router can be used as a parent. PT N Source: T. Winter, P. Thubert, A. Brandt, J. Hui, R. Kelsey, P. Levis, K. Pister, R. Struik , JP. Vasseur, R. Alexander, “RPL: IPv6 Routing Protocol for Low‐Power and Lossy Networks”, IETF, Standards Track, Mar. 2012 Introduction to Internet of Things 15  EL RFID PT N Introduction to Internet of Things 16  Introduction  RFID is an acronym for “radio‐frequency identification” EL  Data digitally encoded in RFID tags, which can be read by a reader.  Somewhat similar to barcodes. PT  Data read from tags are stored in a database by the reader.  As compared to traditional barcodes and QR codes, RFID tag N data can be read outside the line‐of‐sight. Source: “How does RFID work?” AB&R (Online) Introduction to Internet of Things 17  RFID Features  RFID tag consists of an integrated circuit and an antenna. EL  The tag is covered by a protective material which also acts as a shield against various environmental effects.  Tags may be passive or active. PT  Passive RFID tags are the most widely used.  Passive tags have to be powered by a reader inductively before they can transmit information, whereas active tags N have their own power supply. Source: “How does RFID work?” AB&R (Online) Introduction to Internet of Things 18  Working Principle  Derived from Automatic Identification and Data Capture (AIDC) technology. EL  AIDC performs object identification, object data collection and mapping of the collected data to computer systems with little or no human intervention.  AIDC uses wired communication PT  RFID uses radio waves to perform AIDC functions.  The main components of an RFID system include an RFID tag or smart label, an RFID reader, and an antenna. N Source: “How does RFID work?” AB&R (Online) Introduction to Internet of Things 19  EL PT N Introduction to Internet of Things 20  Applications  Inventory management EL  Asset tracking  Personnel tracking  Controlling access to restricted areas   ID badging Supply chain management PT N  Counterfeit prevention (e.g. in the pharmaceutical industry) Source: “How does RFID work?” AB&R (Online) Introduction to Internet of Things 21  EL PT N Introduction to Internet of Things 22  EL Basics of IoT Networking – 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  Functionality-based IoT Protocol Organization  Connectivity (6LowPAN, RPL) EL  Identification (EPC, uCode, IPv6, URIs)  Communication / Transport (WiFi, Bluetooth, LPWAN)  Discovery (Physical Web, mDNS, DNS‐SD)    PT Data Protocols (MQTT, CoAP, AMQP, Websocket, Node) Device Management (TR‐069, OMA‐DM) Semantic (JSON‐LD, Web Thing Model) N  Multi‐layer Frameworks (Alljoyn, IoTivity, Weave, Homekit) Source: Internet of Things Protocols (Online) Introduction to Internet of Things 2  EL MQTT PT N Introduction to Internet of Things 3  Introduction  Message Queue Telemetry Transport. EL  ISO standard (ISO/IEC PRF 20922).  It is a publish‐subscribe‐based lightweight messaging protocol for use in conjunction with the TCP/IP protocol.  MQTT was introduced by IBM in 1999 and standardized by OASIS in 2013. PT  Designed to provide connectivity (mostly embedded) between applications and middle‐wares on one side and networks and N communications on the other side. Source: “MQTT”, Wikipedia (Online) Introduction to Internet of Things 4   A message broker controls the publish‐subscribe messaging pattern.  A topic to which a client is subscribed is updated in the form EL of messages and distributed by the message broker.  Designed for:  Remote connections  Limited bandwidth  Small‐code footprint PT N Source: “MQTT”, Wikipedia (Online) Introduction to Internet of Things 5  MQTT Components EL Lightweight sensors Publishers Applications interested in sensor data Subscribers PT Brokers Connect publishers and subscribers Classify sensor data into topics N Source: “MQTT”, Wikipedia (Online) Introduction to Internet of Things 6  MQTT Methods Connect EL Disconnect Subscribe Unsubscribe Publish PT N Source: “MQTT”, Wikipedia (Online) Introduction to Internet of Things 7  EL PT N Source: “MQTT 101 – How to Get Started with the lightweight IoT Protocol”, HiveMQ (Online) Introduction to Internet of Things 8  Communication  The protocol uses a publish/subscribe architecture (HTTP uses a EL request/response paradigm).  Publish/subscribe is event‐driven and enables messages to be pushed to clients.  The central communication point is the MQTT broker, which is in rightful receivers. PT charge of dispatching all messages between the senders and the  Each client that publishes a message to the broker, includes a topic into the message. The topic is the routing information for the N broker. Source: “MQTT 101 – How to Get Started with the lightweight IoT Protocol”, HiveMQ (Online) Introduction to Internet of Things 9   Each client that wants to receive messages subscribes to a certain topic and the broker delivers all messages with the matching topic to the client. EL  Therefore the clients don’t have to know each other. They only communicate over the topic. PT  This architecture enables highly scalable solutions without dependencies between the data producers and the data consumers. N Source: “MQTT 101 – How to Get Started with the lightweight IoT Protocol”, HiveMQ (Online) Introduction to Internet of Things 10  MQTT Topics  A topic is a simple string that can have more hierarchy levels, EL which are separated by a slash.  A sample topic for sending temperature data of the living room could be house/living‐room/temperature. PT  On one hand the client (e.g. mobile device) can subscribe to the exact topic or on the other hand, it can use a wildcard. N Source: “MQTT 101 – How to Get Started with the lightweight IoT Protocol”, HiveMQ (Online) Introduction to Internet of Things 11   The subscription to house/+/temperature would result in all messages sent to the previously mentioned topic house/living‐ room/temperature, as well as any topic with an arbitrary value in the place of living room, such as house/kitchen/temperature. EL  The plus sign is a single level wild card and only allows arbitrary values for one hierarchy.  If more than one level needs to be subscribed, such as, the entire PT sub‐tree, there is also a multilevel wildcard (#).  It allows to subscribe to all underlying hierarchy levels.  For example house/# is subscribing to all topics beginning with N house. Source: “MQTT 101 – How to Get Started with the lightweight IoT Protocol”, HiveMQ (Online) Introduction to Internet of Things 12 Applications  Facebook Messenger uses MQTT for online chat. EL  Amazon Web Services use Amazon IoT with MQTT.  Microsoft Azure IoT Hub uses MQTT as its main protocol for telemetry messages. PT  The EVRYTHNG IoT platform uses MQTT as an M2M protocol for millions of connected products.  Adafruit launched a free MQTT cloud service for IoT N experimenters called Adafruit IO. Introduction to Internet of Things 13  SMQTT  Secure MQTT is an extension of MQTT which uses encryption EL based on lightweight attribute based encryption.  The main advantage of using such encryption is the broadcast encryption feature, in which one message is encrypted and delivered to multiple other nodes, which is quite common in IoT applications. PT  In general, the algorithm consists of four main stages: setup, encryption, publish and decryption. N Source: M. Singh, M. Rajan, V. Shivraj, and P. Balamuralidhar, "Secure MQTT for Internet of Things (IoT)," in Fifth International Conference on Communication Systems and Network Technologies (CSNT 2015), April 2015, pp. 746‐751 Introduction to Internet of Things 14   In the setup phase, the subscribers and publishers register themselves to the broker and get a master secret key according to their developer’s choice of key generation algorithm. EL  When the data is published, it is encrypted and published by the broker which sends it to the subscribers, which is finally decrypted at the subscriber end having the same master secret key. PT  The key generation and encryption algorithms are not standardized.  SMQTT is proposed only to enhance MQTT security features. N Source: M. Singh, M. Rajan, V. Shivraj, and P. Balamuralidhar, "Secure MQTT for Internet of Things (IoT)," in Fifth International Conference on Communication Systems and Network Technologies (CSNT 2015), April 2015, pp. 746‐751 Introduction to Internet of Things 15  EL PT N Introduction to Internet of Things 16  EL Basics of IoT Networking – 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 CoAP PT N Introduction to Internet of Things 2  Introduction  CoAP – Constrained Application Protocol.  Web transfer protocol for use with constrained nodes and EL networks.  Designed for Machine to Machine (M2M) applications such PT as smart energy and building automation.  Based on Request‐Response model between end‐points  Client‐Server interaction is asynchronous over a datagram N oriented transport protocol such as UDP Source: Z. Shelby , K. Hartke, C. Bormann, “The Constrained Application Protocol (CoAP)”, Internet Engineering Task Force (IETF), Standards Track, 2014 Introduction to Internet of Things   The Constrained Application Protocol (CoAP) is a session layer protocol designed by IETF Constrained RESTful Environment (CoRE) working group to provide lightweight RESTful (HTTP) EL interface.  Representational State Transfer (REST) is the standard interface between HTTP client and servers. PT  Lightweight applications such as those in IoT, could result in significant overhead and power consumption by REST.  CoAP is designed to enable low‐power sensors to use RESTful N services while meeting their power constraints. Source: Z. Shelby , K. Hartke, C. Bormann, “The Constrained Application Protocol (CoAP)”, Internet Engineering Task Force (IETF), Standards Track, 2014 Introduction to Internet of Things 4   Built over UDP, instead of TCP (which is commonly used with HTTP) and has a light mechanism to provide reliability.  CoAP architecture is divided into two main sub‐layers:  Messaging EL  Request/response.  The messaging sub‐layer is responsible for reliability and duplication of messages, while the request/response sub‐layer is responsible for communication.  CoAP has four messaging modes:    Confirmable Non‐confirmable Piggyback PT N  Separate Source: V. Karagiannis, P. Chatzimisios, F. Vazquez‐Gallego, and J. Alonso‐Zarate, "A survey on application layer protocols for the internet of things," Transaction on IoT and Cloud Computing, vol. 3, no. 1, pp. 11‐17, 2015 Introduction to Internet of Things 5  CoAP Position EL Application Request CoAP PT Messages UDP N Source: Z. Shelby , K. Hartke, C. Bormann, “The Constrained Application Protocol (CoAP)”, Internet Engineering Task Force (IETF), Standards Track, 2014 Introduction to Internet of Things  CoAP Message Types Message Types‐CoAP Confirmable EL Non‐Confirmable PT Piggyback Separate N Source: Z. Shelby , K. Hartke, C. Bormann, “The Constrained Application Protocol (CoAP)”, Internet Engineering Task Force (IETF), Standards Track, 2014 Introduction to Internet of Things  CoAP Request-Response Model EL PT N Source: V. Karagiannis, P. Chatzimisios, F. Vazquez‐Gallego, and J. Alonso‐Zarate, "A survey on application layer protocols for the internet of things," Transaction on IoT and Cloud Computing, vol. 3, no. 1, pp. 11‐17, 2015 Introduction to Internet of Things   Confirmable and non‐confirmable modes represent the reliable and unreliable transmissions, respectively, while the other modes are used for request/response.  Piggyback is used for client/server direct communication where the server EL sends its response directly after receiving the message, i.e., within the acknowledgment message.  On the other hand, the separate mode is used when the server response some time to be sent by the server. PT comes in a message separate from the acknowledgment, and may take  Similar to HTTP, CoAP utilizes GET, PUT, PUSH, DELETE messages requests to retrieve, create, update, and delete, respectively N Source: V. Karagiannis, P. Chatzimisios, F. Vazquez‐Gallego, and J. Alonso‐Zarate, "A survey on application layer protocols for the internet of things," Transaction on IoT and Cloud Computing, vol. 3, no. 1, pp. 11‐17, 2015 Introduction to Internet of Things 9  CoAP Request-Response Model EL PT N Source: V. Karagiannis, P. Chatzimisios, F. Vazquez‐Gallego, and J. Alonso‐Zarate, "A survey on application layer protocols for the internet of things," Transaction on IoT and Cloud Computing, vol. 3, no. 1, pp. 11‐17, 2015 Introduction to Internet of Things  Features  Reduced overheads and parsing complexity. EL  URL and content‐type support.  Support for the discovery of resources provided by known CoAP services. notifications. PT  Simple subscription for a resource, and resulting push  Simple caching based on maximum message age. N Source: ”Constrained Application Protocol”, Wikipedia (Online) Introduction to Internet of Things 11  EL XMPP PT N Introduction to Internet of Things 12  Introduction  XMPP – Extensible Messaging and Presence Protocol. EL  A communication protocol for message‐oriented middleware based on XML (Extensible Markup Language).  Real‐time exchange of structured data. PT  It is an open standard protocol. N Source: “XMPP”, Wikipedia (Online) Introduction to Internet of Things 13   XMPP uses a client‐server architecture.  As the model is decentralized, no central server is required.  XMPP provides for the discovery of services residing locally or EL across a network, and the availability information of these services.  Well‐suited for cloud computing where virtual machines, PT networks, and firewalls would otherwise present obstacles to alternative service discovery and presence‐based solutions.  Open means to support machine‐to‐machine or peer‐to‐peer N communications across a diverse set of networks. Source: “XMPP”, Wikipedia (Online) Introduction to Internet of Things 14  Highlights  Decentralization – No central server; anyone can run their EL own XMPP server.  Open standards – No royalties or granted permissions are required to implement these specifications PT  Security – Authentication, encryption, etc.  Flexibility – Supports interoperability N Source: “XMPP”, Wikipedia (Online) Introduction to Internet of Things 15  EL PT N Source: “JabberNetwork.svg”, Wikimedia Commons (Online) Introduction to Internet of Things 16  Core XMPP Technologies Core information about the core XMPP technologies for XML streaming EL Jingle multimedia signalling for voice, video, file transfer Multi‐user Chat PubSub PT flexible, multi‐party communication alerts and notifications for data syndication BOSH N HTTP binding for XMPP Source: “XMPP: Technology Overview”, XMPP.org (Online) Introduction to Internet of Things 17 Weaknesses  Does not support QoS. EL  Text based communications induces higher network overheads.  Binary data must be first encoded to base64 before transmission. PT N Introduction to Internet of Things 18 Applications  Publish‐subscribe systems EL  Signaling for VoIP  Video  File transfer   Gaming PT Internet of Things applications  Smart grid N  Social networking services Introduction to Internet of Things 19  EL PT N Introduction to Internet of Things 20  EL Basics of IoT Networking – 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 AMQP PT N Introduction to Internet of Things 2  Introduction  Advanced Message Queuing Protocol. EL  Open standard for passing business messages between applications or organizations.  Connects between systems and business processes. PT  It is a binary application layer protocol.  Basic unit of data is a frame.  ISO standard: ISO/IEC 19464 N Source: “Advanced Message Queuing Protocol”, Wikipedia (Online) Introduction to Internet of Things 3  EL PT N Source: “The‐amqp‐model‐for‐wikipedia.svg”, Wikimedia Commons (Online) Introduction to Internet of Things 4 AMQP Features EL Organizations Technologies Time Space PT Connects across N Introduction to Internet of Things 5 Features Security EL Reliability Interoperability PT Routing Queuing Open standard N Introduction to Internet of Things 6  Message Delivery Guarantees  At‐most‐once EL  each message is delivered once or never  At‐least‐once  each message is certain to be delivered, but may do so multiple times  Exactly‐once PT  message will always certainly arrive and do so only once N Reference: "OASIS AMQP version 1.0, sections 2.6.12‐2.6.13". OASIS AMQP Technical Committee Introduction to Internet of Things 7  AMQP Frame Types  Nine AMQP frame types are defined that are used to initiate, control and EL tear down the transfer of messages between two peers:  Open (connection open)  Begin (session open)  Attach (initiate new link)      PT Transfer (for sending actual messages) Flow (controls message flow rate) Disposition (Informs the changes in state of transfer) Detach (terminate the link) End (session close) N  Close (connection close) Source: O.S. Tezer, “An advanced messaging queuing protocol walkthrough ”, DigitalOcean (Online), 2013 Introduction to Internet of Things 8  Components Part of Broker Exchange EL Receives messages and routes them to Queues Separate queues for separate business processes Queue Consumers receive messages from queues Bindings PT Rules for distributing messages (who can access what message, destination of the message) N Source: O.S. Tezer, “An advanced messaging queuing protocol walkthrough ”, DigitalOcean (Online), 2013 Introduction to Internet of Things 9  AMQP Exchanges Direct EL Fan‐out PT Topic Header N Source: O.S. Tezer, “An advanced messaging queuing protocol walkthrough ”, DigitalOcean (Online), 2013 Introduction to Internet of Things 10  AMQP Features  Targeted QoS (Selectively offering QoS to links) EL  Persistence (Message delivery guarantees)  Delivery of messages to multiple consumers    PT Possibility of ensuring multiple consumption Possibility of preventing multiple consumption High speed protocol N Source: O.S. Tezer, “An advanced messaging queuing protocol walkthrough ”, DigitalOcean (Online), 2013 Introduction to Internet of Things 11  Applications  Monitoring and global update sharing. EL  Connecting different systems and processes to talk to each other.  Allowing servers to respond to immediate requests quickly and delegate time consuming tasks for later processing. PT  Distributing a message to multiple recipients for consumption.  Enabling offline clients to fetch data at a later time.  Introducing fully asynchronous functionality for systems. N  Increasing reliability and uptime of application deployments. Source: O.S. Tezer, “An advanced messaging queuing protocol walkthrough ”, DigitalOcean (Online), 2013 Introduction to Internet of Things 12  EL PT N Introduction to Internet of Things 13  EL Connectivity Technologies – 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 Communication Protocols The following communication protocols have immediate importance to consumer and EL industrial IoTs:  IEEE 802.15.4  Zigbee  6LoWPAN  Wireless HART  Z‐Wave  ISA 100  Bluetooth  NFC PT N  RFID Introduction to Internet of Things 2  EL IEEE 802.15.4 PT N Introduction to Internet of Things 3  Features of IEEE 802.15.4  Well‐known standard for low data‐rate WPAN. EL  Developed for low‐data‐rate monitoring and control applications and extended‐life low‐power‐consumption uses.  This standard uses only the first two layers (PHY, MAC) plus PT the logical link control (LLC) and service specific convergence sub‐layer (SSCS) additions to communicate with all upper layers N  Operates in the ISM band. Source: L.Fenzel, “What’s The Difference Between IEEE 802.15.4 And ZigBee Wireless?”, Electronic Design (Online), Mar. 2013 Introduction to Internet of Things 4  EL PT N Introduction to Internet of Things 5   Uses direct sequence spread spectrum (DSSS) modulation.  Highly tolerant of noise and interference and offers link reliability improvement mechanisms. EL  Low‐speed versions use Binary Phase Shift Keying (BPSK).  High data‐rate versions use offset‐quadrature phase‐shift keying (O‐QPSK). (CSMA‐CA) for channel access. PT  Uses carrier sense multiple access with collision avoidance  Multiplexing allows multiple users or nodes interference‐free N access to the same channel at different times. Source: L.Fenzel, “What’s The Difference Between IEEE 802.15.4 And ZigBee Wireless?”, Electronic Design (Online), Mar. 2013 Introduction to Internet of Things 6   Power consumption is minimized due to infrequently occurring very short packet transmissions with low duty cycle (