IOT technology-standards

Editor's Notes

• #3: Internet of Things is an aggregation of multiple domains that were previously proprietary, stand-alone (isolated), or difficult to exchange data. It is the interconnection of devices and systems using standardized protocols based on TCP/IP that forms the basis for the Internet of Things
• #5: The major related themes when talking about IoT is presented here. Details will be provided in subsequent slides. This is a Venn diagram of the relationships among the various domains which illustrate their relative importance and commonality / overlap among them. For example: Internet Enabled Appliances are a specific class of IoT devices. Machine to Machine (M2M) communications exists both in proprietary implementations (outside of the IoT and CPS space), but forms a large part of the IoT and CPS communications process as well Radio Frequency Identifier (RFID) consists of two types: passive and active. Passive RFID devices are not considered IoT devices as they do not have ‘intelligence,’ whereas Active RFID devices are generally considered a class of IoT devices. Wireless Sensor Networks (WSN) devices were the direct ‘predecessor’ to what is known as IoT today. Nonetheless, WSN devices do not necessary operate using Internet Protocols, so they exist as a domain outside of IoT space as well. IoT Gateways can be used to interlink non-IP based WSN devices to the Internet. WSN devices which support RFID protocols can also be considered a type of Active RFID. There is a close relationship between IoT and Cyber Physical Systems (CPS), though CPS encompasses a larger scope as it includes monitoring and control of production machinery, utilities, and smart cities which are not often thought of as IoT devices, and many often have security requirements that prohibit them from being accessed over the Internet (though CPS devices may be part of a secured Intranet).
• #6: Enumerating the various domains that will be elaborated upon: Internet Enabled Appliances Machine to Machine Communications (M2M) Radio Frequency Identifier (RFID) Wireless Sensor Networks (WSN) Internet of Things (IoT) Cyber Physical Systems (CPS)
• #7: There are 2 classes of devices: Consumer and Industrial Early consumer devices were based on very low speed, wired, basic protocols (Device ID, On, Off, Status) The early consumer wired protocols were often not very reliable due to noisy wiring (in the home), or lack authentication and security, so anyone can ‘hack’ these systems Industrial application devices were mostly proprietary and (naturally) expensive. Their focus is on reliability, and bandwidth was secondary. Industrial applications such as Supervisory Control and Data Acquisition (SCADA) often has to operate over long distances in remote areas Wired connections were replaced by wireless solutions over time to simplify the deployment of such remote systems (e.g., dedicated radio links, and later Cellular system such as GSM) Standardized protocols such as Fieldbus and Industrial Internet were developed to address factory automation issues (production line control, assembly line robots, etc.) Controller Area Networks (CAN bus) are commonly used in automotive applications (in-car diagnostics and control) Generally wired connections are preferred for Industrial applications due to much better reliability compared with wireless solutions
• #8: Despite the general perception that IoT devices are battery operated wireless gizmos (such as Amazon Dash Buttons), the defintion of IoT is more encompassing. The only criteria for IoT devices is that they perform specific functions (i.e., not PCs for general computing) and have Internet connections Smart phones and Tablets are ‘sort-of’ IoT devices, although they are capable of general computing, they are often used to perform specific tasks (phone, messaging, eBook Reader, etc.) and are portable and wirelessly connected using the Internet Low end devices often do not operate using Internet Protocols due to the high overheads of maintaining TCP/IP communications, both in terms of the protocol complexity as well as the bandwidth overheads (IP Headers are sent with each message) WiFi (and Cellular) which is commonly used for Laptops, Smart Phones and Tablets, uses a lot of energy to operate, and are not suitable for low power IoT devices Due to the large number of devices expected to be part of the IoT ecosystem, IPv4 addresses are insufficient, whereas IPv6 headers are 40 bytes (minimum) resulting in high overheads IoT Gateways bridge these non-IP devices to the Internet, so they are considered as IoT devices as users can access them directly The trend is for wireless communications due to ease of deployment, maintenance and mobility
• #9: Consumer appliances that have Internet access (typically Web-based) are now termed ‘Smart’ The use of Internet Protocols in place of proprietary solutions (especially for home security/monitoring) reduced the cost of implementation, and enables new services/access: remote monitoring using smartphones, cloud based services, etc. Although smart consumer devices are widely known due to expansive marketing, it is only represents a niche area in IoT space. A lot of IoT applications are not consumer facing and hence hidden from public perception
• #10: Exchange of data between machines/systems to perform monitoring and control functions Machine to Machine (M2M) communications were typically proprietary systems using proprietary protocols licensed two-way radio systems (e.g., TETRA) cellular based (GSM) Example of consumer facing M2M communications is the Point of Sale terminal handling Credit Card transaction approvals M2M Messages are often very brief, due to large number of devices to be supported, and limited communication link bandwidths High deployment in utilities, weather sensing from remote stations, and industrial applications Often require long range communications, therefore most short range wireless protocols such as WiFi are not suitable Need for reliability also means unlicensed spectrum (802.15.4, WiFi) are less desirable Modern dedicated energy efficient systems (LoRa, Sigfox) replacing two-way radio and GSM solutions (where bandwidth requirements are suitable) Trend is moving towards cellular standards such as energy efficient LTE-M for IoT usage, and 5G
• #11: Passive RFIDs are not specifically IoT devices The explanation provided is to provide an overview of the topic for a more comprehensive overview of the topic Each RFID can be programmed with a unique Tag ID which allows identification of individual items RFID started as a barcode replacement technology but has evolved to support more efficient logistics and micro-transaction systems due to the ability to store and update data in RFID device using RFID Readers Near Field Communications (NFC) is the latest term for RFID technology (as opposed to Active RFID devices)
• #12: Active RFIDs have a lot in common with WSN devices in terms of the hardware platform. The main difference is that Active RFIDs do not focus on data gathering functions. There may be additional hardware requirements in terms of device security and tamper-proof hardware (to support event logging and validated transactions) Active RFID devices are meant to operate with longer range to support higher mobility speeds and large area monitoring While Passive RFID can only respond when queried by Reader (transponder devices), Active RFID devices can initiate transmissions and act as beacons
• #13: Wireless Sensor Network (WSN) devices are designed to be small, low cost, robust, and have extended battery lifetimes, for deployment in outdoor environments Most WSN application involve sensors (data sources) sending information to a Monitoring station (data sink) We’re usually more interested in the aggregate data obtained by WSN devices rather than data from a specific device. This allows for interchangeability and longer system lifetime since specific devices will fail due to battery exhaustion or other factors In small areas, sensors communicate directly with the Monitoring station However, this is not feasible in large coverage areas due to limited transmission range, so multi-hop communications, where data is forwarded from one sensor to another until it reaches the monitoring station, is used Since multiple WSN devices in a given geographical area may return similar or identical data, some form of data aggregation will be necessary to reduce network traffic in multi-hop network configurations Data aggregation also allows the system to achieve redundancy and device rotation to conserve battery life. If more than one sensor is reporting information for a given area, most of them can be put in sleep mode
• #14: The definition of Internet of Things (IoT) keeps evolving. However, the hardware platforms have a lot in common with WSN devices, except that IoT devices are designed to communicate using TCP/IP network protocols Network effects (device volume and market momentum) drives innovation and have largely made proprietary technologies for applications such as SCADA, surveillance and security monitoring non-competitive in terms of cost The danger of IoT deployment currently is that security issues are not addressed adequately – IoT is also referred to as Insecurity of Things Older proprietary technology may not implement security adequately either, but due to the isolated nature of such systems the exposure and risks are relatively lower Processing requirements of IoT devices is higher than non-IP technology due to the need to support IP-based communication protocols. Higher CPU performance is also needed to support web-based services directly on the device The IoT revolution is very much driven by Moore’s law since higher performance 32-bit microcontrollers used for IoT devices today is as power efficient as older 8-bit devices used in the past
• #15: The focus of Cyber Physical Systems is on the “system” rather than specific components or devices The important feature of CPS is in the feedback (monitoring) and control (output) loop for large systems involving many devices working in tandem The cyber part of CPS refers to the algorithms and data representation used to capture the state and operational behavior of the physical system Examples of Cyber Physical Systems include: Smart utilities that balance renewal energy generation by consumers with grid output depending on time of day and fluctuating demand Self-driving vehicles (e.g., Google Car) which operate without human intervention Traffic management system for smart cities that respond to real-time surges in traffic along specific transportation corridors (e.g., sports events, processions, accidents) CPS are migrating towards the use of IoT devices, due to replacement of proprietary systems by Internet-based solutions in many domains
• #16: The details of spetrum allocation can be found in the IEEE standard documents Sub 1 GHz spectrum is scarce as it has been allocated for other uses in the past where bandwidths were much less that the digital transmissions used today The number of channels refer to the channels that can be used concurrently. The TV White Space spectrum (54 – 862 MHz) in North America is allocated to 802.15.4 as secondary users, i.e., if there are existing services on specific channels, they are not available for use (hence variable number of available channels) The only spectrum that can provide interoperability worldwide is the 2.4 GHz ISM Band. The number of available channels was increased in the 2006 version of the standard. Each channel has 2 MHz of spectrum allocation. Nonetheless, the ISM Bands are shared spectrum so interference from other protocols (e.g., WiFi, Bluetooth), may mean that actual number of available channels are much lower Generally 802.15.4-based devices use non-IP communications due to the small frame sizes (127 bytes per frame) for efficiency reasons IP support is provided by the 6LoWPAN Adaptation Layer which maps IPv6 packets into multiple 127-byte 802.15.4 data frames (this is expanded upon in the Module on Internet Gateways) Lower frequency bands (sub 1 GHz) are preferred for longer range applications such as smart utilities (WiSUN) due to RF propagation characteristics Various extensions to the IEEE 802.15.4 standard include different modulation techniques for the same spectrum Devices that use different modulation types cannot communicate with each other (i.e., they must speak the same ‘language’) Different modulation standards operating in the same area will cause interference with each other (similar to issue with WiFi and Bluetoooth in 2.4 GHz ISM Band)
• #17: The name Bluetooth refers to the ancient Viking King Harald Bluetooth Bluetooth was primarily developed as a cable replacement technology operating in the 2.4 GHz spectrum (shared with other technologies such as WiFi) Although the original Bluetooth standard (1.x) was adopted as an IEEE standard 802.15.1, subsequent versions were not submitted to IEEE for standardization (which are often subsequently adopted by other national standard bodies as equivalent national standards), so they are known as Industry standards under the control of the Bluetooth SIG In a Star Topology devices are slaves under the control of the master (PC). There is a link establishment process where slaves and master have to configure identical PIN numbers to generate an encryption key for further communications. Once the key has been set, communications can established without user intervention. The Bluetooth standard cover many optional components. Most of them refer to Profiles, introduced in Bluetooth 2.x, that define the communication protocols used between devices. Since devices are free to implement subsets of protocols, it is often a hassle to ensure that all devices can interoperate The evolution of Bluetooth since the 2.x version is not very orderly. Bluetooth 3.x depends on the presence of WiFi hardware module to transfer large amounts of data, so it is more of a hybrid technology Bluetooth 4.x (Bluetooth Low Energy) implements an incompatible modulation scheme for low power, broadcast type communications. It was originally developed as Wibree and is now known as “Bluetooth Smart”. Masters need to support classic Bluetooth and Bluetooth Smart concurrently if they want to access both types of devices. Bluetooth 5 increases the range and throughput of Bluetooth Low Energy, and supports Mesh configurations The IoT use cases focus mainly on Bluetooth Low Energy since it was designed for low power battery operation
• #18: WiFi (802.11) technology has become one of the most successful data communications technology as it serves as a replacement for Ethernet cabling Two major frequency bands have been allocated to WiFi usage, 2.4 GHz and 5 GHz. The bandwidth allocation in the 5 GHz UNII band is larger, and is less congested The modulation and channel access techniques in the 2.4 GHz and 5 GHz bands are different from each other Commercial success of WiFi technology has helped to ensure that newer standards maintain backward compatibility with previous standards, i.e., devices supporting 802.11ac will also typically support previous 802.11 a,b,g,n standards 802.11 family of standards have the highest throughput among the other wireless standards presented. However, it is not suitable for battery operated IoT devices since the energy consumption to operate WiFi is much higher (battery life measured in hours). 802.11p has been adopted for use by Vehicular Networks, which uses dedicated spectrum in the ITS (Intelligent Traffic System) Band to avoid interference from other WiFi users There is a new standard 802.11ah that is being developed for IoT use but it is not interoperable with existing 802.11 standards
• #19: Although the standard defines 11 or 14 channels for the 2.4 GHz band, the channel frequencies overlap, and only 3 non-interfering channels can coexist (4 for Japan which has Channel 14) Most enterprise WiFi deployment will use Channels 1, 6 and 11 to maximize the network capacity. Nonetheless, enterprise WiFi deployments have generally moved to use 5 GHz spectrum (802.11a,n) with 2.4 GHz spectrum as fallback Since 2.4 GHz spectrum is the ISM Band, many other users such as wireless microphones, vehicle door entry remotes, wireless keyboard and mice, will cause interference with WiFi Since Bluetooth and WiFi tend to be used together on modern PCs, the 802.15.2 standard was defined to reduce the interference between these two technologies. 802.11 is based on Direct Sequence Spread Spectrum (DSSS) while Bluetooth is based on Frequency Hopping Spread Spectrum (FHSS), which operate using different principles By selecting suitable channel hopping sequences for Bluetooth, it is possible to reduce the number of times when both are transmitting on the same frequencies 802.11b support max bandwidth of 11 Mbps, but actual throughput between two stations is less than 5.5 Mbps, due to the need to perform handshaking before transmission and only one station can transmit at a given time (half-duplex communications). Multicast data transmission where one transmitted packet can be received by multiple stations in the same area is implemented using 2 Mbps for better reliability and Signal to Noise Ratio (SNR)
• #20: 802.11g reuses the channel frequency to implement a different modulation techique (Orthogonal Frequency Division Multiplexing – OFDM) OFDM is more efficient compared to DSSS and can achieve 54 Mbps using similar spectrum bandwidths Nonetheless, the initial preamble transmission allows stations to fall back to older modulation types when necessary To achieve even higher link speeds, new technologies such as Multiple Input Multiple Output (MIMO) which uses multiple antennae to send and receive data is necessary This is combined with larger spectrum per channel (achieved via ‘channel bonding’) to give the 150 Mbps to 600 Mbps link speed of 802.11n For North America, only three 20-MHz channels are available. Consequently only one 40-MHz bonded channel can be utilized. Actual available link speeds depend on whether other 802.11 legacy users exist on the spectrum and how much interference they generate. Usage of bonded channels for 802.11n basically deny 802.11 legacy users access to free spectrum and mixing of 802.11n with older equipment in the same area is not recommended
• #21: This diagram illustrates the clash in spectrum usage between WiFi (22 Mhz), Bluetooth Low Energy (1 Mhz) and Zigbee (802.15.4) (2 MHz) technologies. In order to reduce interference, specific channels not overlapping other major spectrum users is used by Bluetooth Low Energy as Advertisement Channels Nonetheless, the key point of this figure is that spectrum sharing among competing services work only if each service transmit low to moderate amounts of data. High data rate services or too many users will render the ISM band unusable. Applications requiring reliable and timely communications should not depend on 2.4 GHz ISM band for their operation
• #22: The 5.8 GHz UNII Band is mostly used by WiFi services, and has much larger spectrum allocation compared to the 2.4 GHz band The drawback of 5.8 GHz is the coverage area is reduced compared to 2.4 GHz due to RF propagation distance being inversely related to frequency. This can also be an advantage in supporting more users, at the expense of requiring more Access Points to cover the same area compared to 2.4 GHz Gigabit speeds are being achieved through the use of MIMO and Channel Bonding techniques
• #23: These are the less common 802.11 standards that have been developed Most of them are used in niche areas that are not consumer oriented
• #24: The 802.11ah standard is still undergoing development and standardization Narrowband channels to support lower data rates in sub GHz ISM Bands Longer range due to lower frequencies Multihop capability using Relay Access Points (RAP) for range extension Scheduled sleep mode (Target-Wake-Time) to extend battery life Larger number of nodes supported since not all will be transmitting concurrently The target usage is for low bandwidth IoT applications
• #25: Competing technologies such as LoRa and Sigfox are meant for long range transmissions Assume required bandwidths are very low and need infrequent updates Only suitable for remote SCADA and long term environmental data collection and monitoring (not for disaster/unexpected event reporting) Minimal public information available due to proprietary technology Cellular based solutions Cellular solutions operate on spectrum assigned by individual countries Existing cellular solutions are based on GSM which provides only about 10 kbps bandwidth GSM has been used primarily for remote SCADA applications or low bandwidth wide-area applications such as fleet and inventory tracking LTE-based solutions were too energy intensive and meant for high bandwidth applications Cat-M1, NB-IoT (Cat-M2? [Name is not standardized yet]) and EC-GSM-IoT are newer standards introduced for IoT applications in 3GPP Release 12 and 13
• #26: Important standard bodies can be categorized into three categories: Non-government (non-profit) organizations International Electrical and Electronics Engineers (IEEE) is a US based professional body that was instrumental in standardizing many of the networking technologies in use. These standards often form the basis for standards adopted by other international bodies. Internet Engineering Task Force (IETF) is a US-based organization currently operating under the Internet Society as a standards setting organization responsible for Internet-related Protocols International body responsible for defining networking standards (among other important standards) is the International Organization for Standardization (ISO) which standardized the Open System Interconnect (OSI) network reference model. Members in ISO consists of national standard bodies of various countries International Society of Automation (ISA) is a professional body focused on instrumentation and automation. The ISA100.11a standard has been promoted for industrial IoT applications. Government related United Nations body responsible for defining telecommunications standards and spectrum allocation is the International Telecommunications Union (ITU). ITU-T is the Telecommunications Standards Sector responsible for standards related to telecommunications and computer communications Industry-based organizations Various industry-based organizations have been set up to promote and regulate IoT related standards, notably for certification of conformance via interoperability testing, without which products cannot carry the respective certification logo. Most industry-based organizations are funded by commercial memberships and some standard documents are only available to paid members.