Iot module2
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This document discusses various Internet of Things (IoT) access technologies for connecting smart objects, including their range, frequency bands, topology, and power consumption considerations. It provides details on IEEE 802.15.4, IEEE 802.15.4g/e, IEEE 1901.2a, IEEE 802.11ah, and LoRaWAN protocols, outlining their physical layers, MAC layers, topologies, and security features. The document is intended to educate about key technologies enabling connectivity of battery-powered IoT devices over both wireless and power line communication mediums.
Iot module2
- 1. INTERNET OF THINGS MODULE-2 By Dr. Mallikarjunaswamy N J Dr Mallikarjunaswamy N J 1
- 2. Connecting smart objects Connecting smart objects by using 1) Range 2) Frequency bands 3) Topology 4) Power consumption Dr Mallikarjunaswamy N J 2
- 3. Range Dr Mallikarjunaswamy N J 3
- 5. Power consumption Battery-powered nodes bring much more flexibility to IoT devices. These nodes are often classified by the required lifetimes of their batteries. A powered node has a direct connection to a power source, and communications are usually not limited by power consumption criteria. IoT wireless access technologies must address the needs of low power consumption and connectivity for battery-powered nodes. This has led to the evolution of a new wireless environment known as Low-Power Wide-Area (LPWA). Dr Mallikarjunaswamy N J 5
- 6. IoT Access Technologies IEEE 802.15.4: IEEE 802.15.4g and 802.15.4e: IEEE 1901.2a: IEEE 802.11ah: LoRaWAN: Dr Mallikarjunaswamy N J 6
- 7. IEEE 802.15.4: IEEE 802.15.4 is a wireless access technology for low-cost and low-data- rate devices that are powered or run on batteries. This access technology enables easy installation using a compact protocol stack while remaining both simple and flexible. IEEE 802.15.4 is commonly found in the following types of deployments: Home and building automation Automotive networks Industrial wireless sensor networks Interactive toys and remote controls Dr Mallikarjunaswamy N J 7
- 8. ZigBee: It is an IoT solution for interconnecting smart objects. ZigBee solutions are aimed at smart objects and sensors that have low bandwidth and low power needs. The main areas where ZigBee is the most well-known include automation for commercial, retail, and home applications and smart energy. In the industrial and commercial automation space, ZigBee-based devices can handle various functions, from measuring temperature and humidity to tracking assets. Dr Mallikarjunaswamy N J 8
- 9. High-Level ZigBee Protocol Stack Dr Mallikarjunaswamy N J 9
- 10. ZigBee IP Dr Mallikarjunaswamy N J 10
- 11. 802.15.4 Physical and MAC Layer: The 802.15.4 standard supports an extensive number of PHY options that range from 2.4 GHz to sub-GHz frequencies in ISM bands. The original IEEE 802.15.4-2003 standard specified only three PHY options based on direct sequence spread spectrum (DSSS) modulation. DSSS is a modulation technique in which a signal is intentionally spread in the frequency domain, resulting in greater bandwidth. The original physical layer transmission options were as follows: 2.4 GHz, 16 channels, with a data rate of 250 kbps 915 MHz, 10 channels, with a data rate of 40 kbps 868 MHz, 1 channel, with a data rate of 20 kbps Dr Mallikarjunaswamy N J 11
- 12. Dr Mallikarjunaswamy N J 12 802.15.4 Physical and MAC Layer:
- 14. Security The IEEE 802.15.4 specification uses Advanced Encryption Standard (AES) with a 128-bit key length as the base encryption algorithm for securing its data. In addition to encrypting the data, AES in 802.15.4 also validates the data that is sent. This is accomplished by a message integrity code (MIC), which is calculated for the entire frame using the same AES key that is used for encryption. 14
- 15. IEEE 802.15.4g and 802.15.4e Distribution automation and industrial supervisory control and data acquisition (SCADA) environments for remote monitoring and control Public lighting Environmental wireless sensors in smart cities Electrical vehicle charging stations Smart parking meters Microgrids Renewable energy. Dr Mallikarjunaswamy N J 15
- 16. Physical Layer: IEEE 802.15.4g In IEEE 802.15.4g-2012, the original IEEE 802.15.4 maximum PSDU or payload size of 127 bytes was increased for the SUN PHY to 2047 bytes. This provides a better match for the greater packet sizes found in many upper-layer protocols. For example, the default IPv6 MTU setting is 1280 bytes. Fragmentation is no longer necessary at Layer 2 when IPv6 packets are transmitted over IEEE 802.15.4g MAC frames. Also, the error protection was improved in IEEE 802.15.4g by evolving the CRC from 16 to 32 bits. Dr Mallikarjunaswamy N J 16
- 17. 802.15.4e Dr Mallikarjunaswamy N J 17
- 18. 802.15.4e Time-Slotted Channel Hopping (TSCH): Channel hopping, also known as frequency hopping, utilizes different channels for transmission at different times. TSCH divides time into fixed time periods, or “time slots,” which offer guaranteed bandwidth and predictable latency. In a time, slot, one packet and its acknowledgement can be transmitted, increasing network capacity because multiple nodes can communicate in the same time slot, using different channels. A number of time slots are defined as a “slot frame,” which is regularly repeated to provide “guaranteed access.” Dr Mallikarjunaswamy N J 18
- 19. Topology:802.15.4 Deployments of IEEE 802.15.4g-2012 are mostly based on a mesh topology. A mesh topology allows deployments to be done in urban or rural areas, expanding the distance between nodes that can relay the traffic of other nodes. Support for battery-powered nodes with a long lifecycle requires optimized Layer 2 forwarding or Layer 3 routing protocol implementations. This provides an extra level of complexity but is necessary in order to cope with sleeping battery-powered nodes. Dr Mallikarjunaswamy N J 19
- 20. Security:802.15.4 Dr Mallikarjunaswamy N J 20 IEEE 802.15.4g/e MAC Layer Security
- 21. IEEE 1901.2a IEEE 1901.2a-2013 is a wired technology. This is a standard for Narrowband Power Line Communication (NB-PLC). NB-PLC leverages a narrowband spectrum for low power, long range, and resistance to interference over the same wires that carry electric power. Dr Mallikarjunaswamy N J 21
- 22. Physical Layer: IEEE 1901.2a Dr Mallikarjunaswamy N J 22
- 23. MAC Layer: IEEE 1901.2a Dr Mallikarjunaswamy N J 23 Figure 2.14: General MAC Frame Format for IEEE 1901.2
- 24. Topology: IEEE 1901.2a Use cases and deployment topologies for IEEE 1901.2a are tied to the physical power lines. As with wireless technologies, signal propagation is limited by factors such as noise, interference, distortion, and attenuation. These factors become more prevalent with distance, so most NB-PLC deployments use some sort of mesh topology. Mesh networks offer the advantage of devices relaying the traffic of other devices so longer distances can be segmented. 24
- 25. Security: IEEE 1901.2a IEEE 1901.2a security offers similar features to IEEE 802.15.4g. Encryption and authentication are performed using AES. I In addition, IEEE 1901.2a aligns with 802.15.4g in its ability to support the IEEE 802.15.9 Key Management Protocol. Dr Mallikarjunaswamy N J 25
- 26. IEEE 802.11ah In unconstrained networks, IEEE 802.11 Wi-Fi is certainly the most successfully deployed wireless technology. Wi-Fi lacks sub-GHz support for better signal penetration, low power for battery-powered nodes, and the ability to support a large number of devices. Hence the IEEE 802.11 working group launched a task group named IEEE 802.11ah to specify a sub-GHz version of Wi-Fi. Dr Mallikarjunaswamy N J 26
- 27. physical layer: IEEE 802.11ah IEEE 802.11ah essentially provides an additional 802.11 physical layer operating in unlicensed sub-GHz bands. Various countries and regions use the following bands for IEEE 802.11ah: 868–868.6 MHz for EMEAR, 902–928 MHz and associated subsets for North America and Asia-Pacific regions, and 314–316 MHz, 430–434 MHz, 470–510 MHz, and 779–787 MHz for China. Based on OFDM modulation, IEEE 802.11ah uses channels of 2, 4, 8, or 16 MHz. Ex: At a data rate of 100 kbps, the outdoor transmission range for IEEE 802.11ah is expected to be 0.62 mile. Dr Mallikarjunaswamy N J 27
- 28. MAC Layer: IEEE 802.11ah The IEEE 802.11ah MAC layer is optimized to support the new sub-GHz Wi-Fi PHY while providing low power consumption and the ability to support a larger number of endpoints. Enhancements and features specified by IEEE 802.11ah for the MAC layer include the following: Number of devices: Has been scaled up to 8192 per access point. MAC header: Has been shortened to allow more efficient communication. Dr Mallikarjunaswamy N J 28
- 29. Topology: IEEE 802.11ah While IEEE 802.11ah is deployed as a star topology, it includes a simple hops relay operation to extend its range. This relay operation can be combined with a higher transmission rate or modulation and coding scheme (MCS). This means that a higher transmit rate is used by relay devices talking directly to the access point. The transmit rate reduces as you move further from the access point via relay clients. Sectorization is a technique that involves partitioning the coverage area into several sectors to get reduced contention within a certain sector. This technique is useful for limiting collisions in cells that have many clients. Dr Mallikarjunaswamy N J 29
- 30. IEEE 802.11ah Sectorization Dr Mallikarjunaswamy N J 30 •Security •Similar to IEEE 802.11 specifications •Competitive Technologies •Competitive technologies to IEEE 802.11ah are IEEE 802.15.4 and IEEE 802.15.4e
- 31. Security: IEEE 802.11ah Similar to IEEE 802.11 specifications Competitive Technologies Competitive technologies to IEEE 802.11ah are IEEE 802.15.4 and IEEE 802.15.4e Dr Mallikarjunaswamy N J 31