There are many types of wireless technologies suitable for IoT applications. This blog article outlines them and explains which applications are suitable for which technologies. It also looks at the issue of standards and how these affect the roll out and reliability of the technologies. You will also find out information about the wireless technology chosen for the 8power harvesting sensors.
Low Power Wide Area Networks (LPWANs) are the recent development specifically designed for the requirements for IoT. Generally these wireless systems provide long-range communication. They use low cost, low power radios and, inexpensive batteries that aim to last for years. This type of technology can support large-scale IoT networks sprawling over vast industrial and commercial campuses.
However, like all things in life, not all LPWANs are created equal. The main difference to consider is operating in either the licensed spectrum (Cellular, NB-IoT, LTE-M) or unlicensed spectrum (LoRa, Sigfox, Ingenu etc.). There are pros and cons for each approach and offer varying degrees of performance in key network factors. For instance, power consumption is a significant issue for cellular-based, licensed LPWANs. Quality-of-Service, coverage and scalability are main considerations when adopting unlicensed technologies.
Security is an important consideration for use of this technology. Both NB-IoT and LTE-M derive from the LTE authentication and encryption security features making them more secure than many WLAN systems.
Unlicensed LPWANs are restricted in how often the radios can transmit as the spectrum is shared. These systems are suitable for supporting a wide range of applications. These include remote monitoring, smart metering and worker safety to building controls and facility management. However, as LPWANs can only send small blocks of data at a low rate, they are therefore better suited for use cases that don’t require high bandwidth and are not time-sensitive.
Standardization is another important factor to think of if you want to ensure reliability, security, and interoperability in the long run. Selecting the best wireless technology for your IoT applications, requires an accurate assessment of bandwidth, QoS, security, power consumption and network management.
2. Cellular (4G and 5G)
In the consumer mobile markets, cellular networks operating over 4G offer broadband communication supporting voice calls and video streaming applications. However, they are quite costly. They have significant power requirements and indoor coverage partially in industrial environments can be challenging. They do however make an excellent choice as back haul from an LPWAN system. Ultimately IoT data needs to be delivered over the Internet with 4G being the best choice for bandwidth, scalability and interoperability globally.
5G has received both good and not so good press coverage recently. The technology promises high-speed mobility support and ultra-low latency. It is positioned to be the future of autonomous vehicles and augmented reality. Latency or round-trip time for communications in 5G should be ten times less than in 4G, making it the obvious choice for time critical applications such as public safety, connected health and some industrial deployments.
The industry standards group 3GPP chose the 5G NR (New Radio) standard together with LTE as their proposal for submission to the IMT-2020 standard and offers significant increase gigabit per second in both upload & download speeds.
3. Zigbee and Other Mesh Protocols
Zigbee is a short-range, low-power, wireless standard (based on IEEE 802.15.4), commonly used to extend coverage by relaying sensor data over multiple sensor nodes. Compared to LPWAN, Zigbee provides higher data rates, but at the same time, much less power-efficiency due to mesh configuration.
Because of their physical short-range (< 100m), Zigbee is best-suited for medium-range IoT applications with an even distribution of nodes in close proximity. Typically, Zigbee is a complement to Wi-Fi for various home automation use cases like smart lighting, HVAC controls, security and energy management, etc. – leveraging home sensor networks.
4. Bluetooth and BLE
In the area of Wireless Personal Area Networks, Bluetooth is a short-range communication technology used commonly in the consumer marketplace. Bluetooth Classic was originally intended for point-to-point or point-to-multipoint (up to seven slave nodes) data exchange among consumer devices. The original target application was cable replacement for PC peripherals such as printer, mice & keyboards.
Bluetooth Low-Energy or BLE is widely integrated into fitness and medical wearables (e.g. smartwatches, glucose meters, pulse oximeters, etc.) as well as Smart Home devices (e.g. door locks) – whereby data is conveniently communicated to and visualized on smartphones. The inherent low power design of BLE makes it an ideal choice for these kinds of consumer applications as it also allows interoperability with mobile devices and gateways.
The latest versions Bluetooth and BLE are suitable for many industrial IoT applications as they have lower power consumption and extended range mode. Bluetooth™ 5/Bluetooth Low Energy works very well in situations where sensors are deployed for extended period and battery changes are to be avoided. The big advantage is vastly improved power consumption and reduced communication requirements done by simplifying the protocol and allowing the devices to skip connection intervals to conserve battery when not needed. It is also one of the least expensive IoT technologies to use.
Wi-Fi, given its critical role in providing high-throughput data transfer for both enterprise and home environments is widely available. However, for IoT applications, its major limitations in coverage, scalability and power consumption make the technology much less prevalent.
Wi-Fi is energy intensive so therefore often not a feasible solution for large networks of battery-operated IoT sensors, especially in industrial IoT and smart building scenarios. Instead, it is more suitable for connecting devices that can be conveniently connected to power outlets like smart home gadgets and appliances.
Wi-Fi 6, the newest Wi-Fi generation brings in greatly enhanced network bandwidth (i.e. <9.6 Gbps) to improve data throughput per user in congested environments. The new standard is poised to improve customer experience with new digital mobile services in retail and mass entertainment sectors. Also, in-car networks for infotainment and on-board diagnostics are expected to benefit from the use of Wi-Fi 6. Roll out will likely take time as infrastructure is not replaced regularly.
Radio Frequency Identification (RFID) uses radio waves to transmit small amounts of data from an RFID tag to a reader within a very short distance. The technology has been used in retail and logistics sectors.
By attaching an RFID tag to all sorts of products and equipment, businesses can track their inventory and assets in real-time, allowing for better stock and production planning as well as optimized supply chain management. Alongside increasing IoT adoption, RFID continues to be entrenched in the retail sector, enabling new IoT applications like smart shelves, self-checkout, and smart mirrors.
8power Harvesting Technology
The one remaining challenge in all IoT deployments is that of power. Even the most frugal of sensors will still be limited by the onboard battery capacity. In most cases adding more bigger batteries will not solve the problem as batteries degrade over time even when not used and temperature has a massive impact of cell capacity & system leakage.
To address this problem in the industrial IoT space 8power sensors can use energy harvesting to generate their own power from the vibration found in rotating machinery. This power is stored locally in a small rechargeable cell and is used to drive the sensors, processor and is wireless. The benefit of this approach is that these high performance sensors can be considered as “Fit & Forget” for up to 10 years.
Many of 8power customer sites are remote so coverage is key too. We typically will have many sensors on a single site so using a gateway to aggregate traffic is more efficient because we can put more intelligence into the gateway. Edge processing the data also allows the system to reduce the cellular data sent to the cloud reducing costs and only needing one SIM and contract to manage.
For more information about 8power harvesting sensors, please contact us.