Connectivity is the Lifeblood of Edge Computing
April 05, 2022
The IoT ecosystem encompasses many devices that enable the emergence of diverse and innovative applications in wearables, home automation, smart buildings, industrial automation, medical devices, and many more. The reliability of these applications depends on the ability of IoT devices to communicate with each other, and wireless networks are fundamental to this connectivity.
Different Applications Need Different Protocols
Applications vary significantly in their networking requirements, with various wireless communication standards gaining market prominence. These standards ensure the secure interoperability of devices, and each one provides different networking characteristics, targeting the needs of different applications. Many nodes may be powered by a battery or from alternative energy sources, for example, making low power consumption essential so that the device can operate for extended periods on a single charge. On the other hand, the focus may be on data transfer rates and range for devices connected to the power grid.
Network topologies also vary according to the application (See Figure 1). Some sensor arrays may be arranged with the edge device as the hub in a star configuration, while mesh networks are increasingly used to support applications in the home, such as intelligent lighting.
Figure 1: IoT devices can use several different network topologies.
Along with the factors discussed above, selecting the optimal wireless protocol also depends upon the application’s security requirements and the availability of development environments that support cloud access and multi-protocol development. Seven main wireless protocols within the IoT ecosystem are currently prominent (See Figure 2).
Fig 2: Most commonly used wireless protocols in the IoT ecosystem. (Source: Fig 5.3 in Essentials of Edge Computing by NXP)
The current generation of Wi-Fi, Wi-Fi 6, has evolved to support higher bandwidth, speed, lower latency, and a large number of reliable connections. Based on the IEEE 802.11ax standard, Wi-Fi 6 operates in the 2.4, 5, and 6GHz bands. Wi-Fi access points operate as gateways, enabling multiple client devices to access the internet and connect with each other. Access points support concurrent, multi-band operation with high bandwidth, latency-sensitive applications using 5/6GHz band, and devices with low data rates and longer-range requirements using 2.4GHz. Wi-Fi Direct enables a direct connection between two client devices.
Zigbee, Thread, and Bluetooth LE
Zigbee, Thread, and Bluetooth Low Energy (Bluetooth LE) are short-range networking protocols that support low power requirements and enable mesh networking. Each protocol has its own characteristics, such as maximum network size, throughput, and latency. However, all three support the creation of low-power, low-data networks, making them ideal for home and building automation applications. Both Zigbee and Thread are based upon the IEEE 802.15.4 PHY and MAC layers and operate in the 2.4GHz band. As each protocol evolves, the performance differences between them continue to decrease. When choosing one over another, one of the most important decision-making factors may become the maturity of their respective ecosystems.
Designed originally for high-rate data communications, ultra-wideband (UWB) has evolved into a uniquely secure, fine-ranging technology based on the IEEE 802.14.4a standard. UWB radios can be embedded in devices such as smartphones, wearables, and smart keys and use techniques known as “ranging” and “time-of-flight” (ToF) to accurately measure the distance to another UWB device when it moves into range. Typical use cases for UWB include hands-free payments, indoor navigation, secure hands-free access, and item tracking.
Near Field Communication
Near Field Communication (NFC) operates within the High Frequency (HF) range of the RFID spectrum to store and transmit data. As a proximity technology, NFC only works when two devices are near each other, enabling low-power operation. A well-established technology for access control and contactless mobile payments, NFC-enabled devices can function as temporary touchscreens, enabling operator configuration of other products, such as industrial machinery and automobiles.
With its increased data speeds, larger network capacities, and reduced latencies, 5G is increasingly being adopted for long-range connectivity. Its capabilities promise to bring the power of machine learning and artificial intelligence (AI) to the edge, and its low latencies will enable a range of real-time applications such as vehicle-to-everything (V2X) connectivity, virtual reality applications, and smart manufacturing.
Time to Market is Critical in the IoT Ecosystem
In today’s innovative IoT market, a growing number of IoT devices are being designed with multi-protocol functionality, offering increased flexibility to application developers (Figure 3). Bluetooth LE, for example, can connect devices to an existing home automation network with Thread or Zigbee interacting with other devices on the same network.
Fig 3: Multi-protocol devices enable flexible but complex applications. (Source: Fig 5.25 in Essentials of Edge Computing by NXP)
At the same time, cloud connectivity is becoming a default requirement for IoT applications, bringing benefits such as remote diagnostics, over-the-air (OTA) upgrades, remote device management, and enhanced compute capability at the Edge.
However, for the designer faced with ever-shrinking development cycles, harnessing the additional flexibilities of multi-protocol devices while grappling with the complexities of cloud connectivity threatens to add both cost and time to already stretched projects.
Fortunately, in parallel with these hardware and software developments, a growing range of toolsets are available to ease the development task. Matter, for example, is a unifying, IP-based connectivity protocol that simplifies the development of multi-protocol systems. An open-source standard, Matter enables developers to connect and build dependable, secure IoT ecosystems and increase compatibility among smart home devices.
In parallel, many cloud providers, including Amazon Web Services (AWS), Microsoft® Azure®, and Google Cloud, provide IoT software development kits (SDKs), making it easier to connect to the cloud from an IoT device.
Edge Computing Depends Upon Connectivity
Effective and secure edge computing relies on all devices in the IoT ecosystem communicating with each other. As the range of applications expands, their communications needs become more complex. Devices and protocols have evolved to support these needs and, to harness the power of the flexibility on offer, developers increasingly rely on comprehensive hardware and software toolkits.