It's a curious fact that the Internet of Things (IoT) movement – one that relies on pervasive connectivity – suffers from an overload of available communications. Particularly when surveying the wireless Machine-to-Machine (M2M) landscape, developers of edge nodes and gateway platforms alike are faced with excessive connectivity options that make selecting the right form of communication challenging, which often results in trade-offs between highly optimized proprietary protocols and the interoperability benefits of widely used wireless standards.

Because proprietary technology lends well to specific applications, to date it has dominated most short-range IoT connectivity. However, improved standardized options such as Bluetooth, ZigBee, and Z-Wave are beginning to offset those advantages according to analysts at IHS (ihs.com), and although the breadth of IoT applications will still require a heterogeneous mix of connectivity, communications standards are making inroads thanks to smartphone adoption and increased use in home automation.

“There wasn't a lot of thought given to this broader, IoT utopia viewpoint where you want to have all of these devices interconnected and talking to each other and sharing data – that has been much more prevalent over the last few years,” says Bill Morelli, Associate Director, Internet of Things & M2M, Digital ID & Security, IHS. “Consequently, you've got a lot of very optimized technologies being used for a very specific purpose. Now the cost balance is starting to tip a little bit on those, and folks are starting to see where the open standard technologies and things like Bluetooth Smart can work at a comparable power level and are more widely supported. As you start getting into issues like consumerization of industry and consumerization of enterprise where you have more consumer devices there, folks are starting to realize, ‘Wait, maybe I want this device to talk to more than just the equipment in my factory, so whether it's through a software abstraction layer or because I'm using a common protocol, I need to start thinking about that.' It's going to happen slowly but we do expect to see that start to transition.”

Consumerization drives short-range standards

Morelli points out that “consumerization of industry” will be a driving factor in short-range connectivity, reflecting how IoT rollouts are blurring lines between “commercial” and “embedded.” For standards-based communications that emphasize low power this crossover into embedded determinism should continue, says Les Santiago, Research Director, Wireless Semiconductors, IDC (idc.com).

“Note that short range wireless connectivity is the ‘plumbing' that the IoT/M2M space needs to really move forward to deliver on its promise of real time and Big Data analytics,” Santiago says. “We think ZigBee, Bluetooth Low Energy (BLE), and Wi-Fi will be contenders for the top spots for connectivity. ZigBee has certain advantages that the others do not have such as the life of the battery exceeding the life of the device. With the billions of end nodes including sensors, changing batteries every few months is not going to be an option. So low power will be a key differentiator for these connectivity technologies.”

”The current big leg for ZigBee volume is in RF remote controls, which actually led to its position in service provider Set Top Boxes (STBs) and home automation,” says Lee Ratliff, Principal Analyst, Broadband & Digital Home, IHS. “Z-Wave missed the smart meter, but found earlier success in home automation through service providers and also with a significant retail channel. Still, Z-Wave has a fraction of ZigBee volume due to the missing meter and remote market segments. Bluetooth Smart growth is exploding in wearables and is making inroads in PC peripherals, health, and home automation. Bluetooth Smart unit volume grew 5x in 2013 due to native iOS implementation starting with the iPhone 4S and continuing with all subsequent iPhones. Bluetooth Smart is also natively included in Android.”

From 2013 to 2018 IHS projects Compound Annual Growth Rates (CAGRs) of 65 percent, 22 percent, and 39 percent for Bluetooth Smart, ZigBee, and Z-Wave, respectively, with growth in proprietary wireless flattening by the end of the sample period.

Shrinking connectivity and software abstraction

As IDC's Santiago notes, IoT connectivity will remain fragmented with specific vertical strongholds, especially as technologies like 6LoWPAN begin competing in sensor grid applications. Morelli of IHS mirrors this, stating that abstraction layers may be the next technology iteration that impacts the IoT connectivity quandary.

“Particularly in the next two-to-five years, I think a lot of the technologies are going to shake out and we'll see it get down to a smaller number than it is today. It won't go down to one or even five, but it's not going to be dozens either,” Morelli says. “The other thing we're going to start to see is an increasing focus on software layers that can interact with multiple types of radios so you can have a factory or an industrial environment with several different types of systems that are able to talk to each other through this software layer. That may be something like 6LoWPAN or another flavor of that.”