Connectivity options for the IoT

-October 31, 2017

The wireless connectivity options for the Internet of Things (IoT) are numerous and varied. That there are so many options is in part a function of the growing number of IoT use-case categories, each having a distinct set of requirements that balance factors including power, connectivity range, network latency, the frequency and size of data exchange, and the location(s) of processing resources.
Designers of IoT devices will have to sort out which connectivity options will make the most sense for the target application. And because most use cases are still developing and there are multiple connectivity options for each of those use cases, designers will occasionally be forced to bet on one option rather than another.

This is a rundown of prominent connectivity options for IoT, along with notes on recent developments, when applicable. The first set of options includes wireless local area network (LAN) and personal area network (PAN) standards. The second set includes wireless wide area network (WAN) standards.

Wireless LANs and PANs based on Wi-Fi, Bluetooth, Z-Wave, and Zigbee have been around for years. The home was one of the first environments to get crammed with connected devices that would ultimately be retrofitted with the IoT label. If the associated applications have anything in common, it’s that the devices being connected have a plug-in power source (usually with battery backup) or incorporate a battery good for hours of operation before requiring a recharge. Anyone designing any IoT product that will operate in environments where these wireless communications technologies are already established will naturally have to consider using them, even as competing connectivity options are proposed.

Wi-Fi: The number of devices being connected in any Wi-Fi-enabled home or office is increasing. In response Wi-Fi is being made more robust, notably with the incorporation of mesh networking. Meanwhile, new and more capable versions of IEEE 802.11 are on the way. Broadcom and Quantenna just announced what they claim is the world’s first full-duplex 802.11ax mesh chipset. SK Telecom recently announced it got an access point based on 802.11ax to transfer data at 4.8 Gbps (the current version, 802.11ac, sustains 1.3 Gbps). Wi-Fi will thrive without additional IoT duties; should IoT applications come to rely widely on Wi-Fi, that will merely amplify Wi-Fi’s growth.

Bluetooth: Traditional Bluetooth tends to be used for very short-range connectivity, but it’s not a particularly low power option, as Zigbee is, so it tends to drain battery-operated devices. Hence the newer version of the standard called Bluetooth Low Energy (BLE), designed for PAN. IoT applications that require PANs tend to be characterized by a limited number of things in close proximity that need to be connected; often one or more of the things being connected is mobile (smartphone and wireless earbuds, for example). At the moment, Bluetooth seems ensconced in these applications. This past summer, Bluetooth developers also introduced Bluetooth Mesh specifically for connecting home products. The first target market is connected light bulbs. Will that be a big enough toehold from which to launch a competition with Zigbee, Z-Wave, and Thread?

Zigbee: One of the first low-power mesh networking technologies, Zigbee is good for supporting connections among multiple devices, which has helped it become ensconced in in-home automation systems. It has also become popular in remote controls, particularly the RF4CE version. Zigbee’s security was compromised in 2015, but developers have been working on that. Zigbee has traditionally been the preference when support for faster data rates is desired.

Z-Wave: Another mesh option, Z-Wave has been around for more than 15 years and is already built into a couple of thousand products. It operates in different frequency bands in different countries, but in all instances it avoids the unlicensed and consequently crowded 2.4 GHz band. Like Zigbee, Z-Wave’s security was compromised in the recent past and, as with Zigbee, advocates have shored it up. Z-Wave tends to get chosen when farther connectivity reach is one of the design criteria.

Thread: Developed only in the last few years, Thread is a protocol that operates on 6LoWPAN, an acronym comprised of its intrinsic characteristics: IPv6, low-power, wireless and PAN. Like Zigbee, Thread conforms to the IEEE 802.15.4 low-rate wireless PAN standard. The organizations behind each decided two years ago to make Zigbee and Thread interoperable. Thread has one of the faster PAN data rates, and it was designed from the ground up with security in mind (as was Bluetooth Mesh), which feels more salient every time yet another connected product is hacked. Thread’s prospects are currently tied to the fortunes of its biggest adherent, Nest, currently one of the leading names in home automation products.

More IoT applications for personal, residential, and office use are coming. The market for home automation is still developing. Connected appliances are apt to become more popular. There has been fitful progress integrating home automation systems and utility monitoring systems for advanced control and smarter device management, but that integration trend is likely to continue.

The last 20 years or so have also seen small, lurching steps in telemedicine; future progress is expected to be steadier and smoother. The industry has seen halting attempts to bridge home automation systems with smart utilities; the goal is to manage home systems more efficiently, ideally saving money for both utilities and their customers.

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