Internet of Things (IoT) - Physical and Logical Design - PDF

Istanbul Beykent University INTERNET OF THINGS DEPARTMENT OF COMPUTER ENGINEERING 1 Physical Design Of IoT 1. Things in IoT 2. Protocols 2 Things in IoT The things in IoT...

Istanbul Beykent University INTERNET OF THINGS DEPARTMENT OF COMPUTER ENGINEERING 1 Physical Design Of IoT 1. Things in IoT 2. Protocols 2 Things in IoT The things in IoT refers to IoT devices which have unique identities and perform remote sensing, actuating and monitoring capabilities. IoT devices can exchange data with other connected devices applications. It collects data from other devices and process data either locally or remotely. An IoT device may consist of several interfaces for communication to other devices both wired and wireless. These includes I/O interfaces for sensors, (ii) Interfaces for internet connectivity (iii) Memory and storage interfaces and (iv) audio/video interfaces. 3 Things in IoT 4 IoT Protoc ols 5  Link Layer Link Layer : Protocols determine how data is physically sent over the network‘s physical layer or medium. Local network connect to which host is attached. Hosts on the same link exchange data packets over the link layer using link layer protocols. Link layer determines how packets are coded and signaled by the h/w device over the medium to which the host is attached. 6 Link Layer Protocols 802.3-Ethernet: IEEE802.3 is collection of wired Ethernet standards for the link layer. Eg: 802.3 (10BASE5)uses co- axial cable; 802.3i (10BASE-T)uses copper twisted pair connection; 802.3j (10BASE-F)uses fiber optic connection; 802.3ae uses 10Gbit/s Ethernet over fiber. These standards provide data rates from 10Mb/s to 40Gb/s. 802.11-WiFi: IEEE802.11 is a collection of wireless LAN(WLAN) communication standards including extensive description of link layer. Eg: 802.11a operates in 5GHz band, 802.11b and 802.11g operates in 2.4GHz band, 802.11n operates in 2.4/5GHz band, 802.11ac operates in 5GHz band, 802.11ad operates in 60Ghzband. 7 Link Layer Protocols 802.16 - WiMax: IEEE802.16 is a collection of wireless broadband standards including exclusive description of link layer. WiMax provide data rates from 1.5 Mb/s to 1Gb/s. 802.15.4-LR-WPAN: IEEE802.15.4 is a collection of standards for low rate wireless personal area network(LR-WPAN). Basis for high level communication protocols such as ZigBee. Provides data rate from 40kb/s to250kb/s. 2G/3G/4G-Mobile Communication: Data rates from 9.6kb/s(2G) to up to100Mb/s(4G). 8 Network/Internet Layer Network/Internet Layer: Responsible for sending IP datagrams from source n/w to destination n/w. Performs the host addressing and packet routing. Datagrams contains source and destination address. Protocols: IPv4: Internet Protocol version4 is used to identify the devices on a n/w using a hierarchical addressing scheme. 32 bit address. Allows total of 2^32addresses. IPv6: Internet Protocol version6 uses 128 bit address scheme and allows 2^128 addresses. 6LOWPAN: (IPv6overLowpowerWirelessPersonalAreaNetwork)operates in 2.4 GHz frequency range and data transfer 250 kb/s. 9 Transport Layer Protocols Transport Layer: Provides end-to-end message transfer capability independent of the underlying n/w. Set up on connection with ACK as in TCP and without ACK as in UDP. Provides functions such as error control, segmentation, flow control and congestion control. Protocols: TCP: Transmission Control Protocol used by web browsers(along with HTTP and HTTPS), email(along with SMTP, FTP). Connection oriented and stateless protocol. IP Protocol deals with sending packets, TCP ensures reliable transmission of protocols in order. Avoids n/w congestion and congestion collapse. UDP: User Datagram Protocol is connectionless protocol. Useful in time sensitive applications, very small data units to exchange. Transaction oriented and stateless protocol. Does not provide guaranteed delivery. 10 Application Layer protocols Application Layer: Defines how the applications interface with lower layer protocols to send data over the n/w. Enables process-to- process communication using ports. Protocols: HTTP: Hyper Text Transfer Protocol that forms foundation of WWW. Follow request- response model Statelessp rotocol. CoAP: Constrained Application Protocol for machine-to- machine(M2M) applications with constrained devices, constrained environment and constrained n/w. Uses client- server architecture. WebSocket: allows full duplex communication over a single socket connection. 11 Application Layer protocols MQTT: Message Queue Telemetry Transport is light weight messaging protocol based on publish- subscribe model. Uses client server architecture. Well suited for constrained environment. XMPP: Extensible Message and Presence Protocol for real time communication and streaming XML data between network entities. Support client-server and server-server communication. DDS: Data Distribution Service is data centric middleware standards for device-to-device or machine-to-machine communication. Uses publish-subscribe model. AMQP: Advanced Message Queuing Protocol is open application layer protocol for business messaging. Supports both point-to-point and publish-subscribe model. 12 IoT Functional Blocks 13 LOGICAL DESIGN of IoT Refers to an abstract represent of entities and processes without going into the low level specifies of implementation. 1) IoT Functional Blocks 2) IoT Communication Models 3) IoT Communication APIs 14 LOGICAL DESIGN of IoT IoT Functional Blocks: Provide the system capabilities for identification, sensing, actuation, communication and management. 15 IoT Functional Blocks  Device: An IoT system comprises of devices that provide sensing, actuation, monitoring and control functions.  Communication: handles the communication for IoT system.  Services: for device monitoring, device control services, data publishing services and services for device discovery.  Management: Provides various functions to govern the IoT system.  Security: Secures IoT system and priority functions such as authentication, authorization, message and context integrity and data security.  Application: IoT application provide an interface that the users can use to control and monitor various aspects of IoT system. 16 Stateless Vs Stateful Protocol A stateless protocol does not require the server to retain session information or status about each communicating partner for the duration of multiple requests. In contrast, a protocol that requires keeping of the internal state on the server is known as a stateful protocol. 17 IoT Communicatio n Models 1) Request-Response 2) Publish-Subscribe 3) Push-Pull 4) Exclusive Pair 18 Request- Response In which the client sends request to the server and the server replies to requests. Is a stateless communication model and each request-response pair is independent of others. 19 Request-Response 20 Publish-Subscribe Involves publishers, brokers and consumers. Publishers are source of data. Publishers send data to the topics which are managed by the broker. Publishers are not aware of the consumers. Consumers subscribe to the topics which are managed by the broker. When the broker receives data for a topic from the publisher, it sends the data to all the subscribed consumers. 21 Publish-Subscribe 22 Push-Pull In which data producers push data to queues and consumers pull data from the queues. Producers do not need to aware of the consumers. Queues help in decoupling the message between the producers and consumers. 23 Push-Pull 24 Exclusive Pair It is bi-directional, fully duplex communication model that uses a persistent connection between the client and server. Once connection is set up it remains open until the client send a request to close the connection. Is a stateful communication model and server is aware of all the open connections. 25 Exclusive Pair 26