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How IoT Short-Range Connectivity
Stacks up in Home Automation

Read the full EIT Home Automation eBook:

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By Carolyn Mathas for Mouser Electronics

Home automation is the use of networking technology to connect and communicate with other devices inside and outside of the home. Light switches, surveillance cameras, energy meters, and thermostats are integral parts of the smart home, monitored with home automation.

Behind home automation technology are a myriad of connectivity and communication standards. Since the inception of the Internet of Things (IoT), standards readily compete against each other to perform pretty much the same task. Of course, advantages and disadvantages exist for each. The challenge becomes wading through the seven most available-but-exclusive solutions that connect IoT over short distances, making IoT the subject of confusion and frustration more often than not. For system and device designers building home automation solutions, IoT connectivity can be understood more readily if we break it down into short-range versus longrange. The topic for discussion in this chapter is shortrange technologies such as Wi-Fi, Bluetooth, Zigbee, Z-Wave, Thread, 6LoWPAN, and solutions found under the 802.15.4 standard.

Short-range solutions require:

• IoT devices that communicate with each other over a network, preferably mesh
• The ability to support a large number of networked IoT devices
• Enabling IoT devices to operate on coin cell batteries for years
• Robust security
• The lowest possible complexity and hardware costs
• Internet Protocol Version 6 (IPv6)

Enabling IoT Short-range Solutions

The information gathered by IoT devices must be aggregated, processed, and analyzed locally and over a greater distance to access the cloud. Information gathered via wireless-enabled sensors may be small, and, except for Wi-Fi, all short-range IoT connectivity options incorporate a variety of networking capabilities. Mesh networking is best suited for devices that communicate without data passing through a router or gateway hub.

Power Consumption: A Critical Factor

In home automation systems, power delivery can occur through 120VAC coin cells or small batteries in indoor devices, and potentially solar cells for outdoor devices. The majority of IoT devices must be battery powered, with connectivity solutions designed accordingly. It isn’t just the power source, it’s the product’s expectation for power that is important. Devices themselves consume little power, and the network must use communication techniques based on low data rates and minimal sensor radio-frequency (RF) transmit power. While constant communication is typically not an issue, IoT devices need to be able to receive a command from an external source, such as a long-range communication system, and from the components involved. This is accomplished via sleep mode, whereby functions awake to detect activity from the component the sensor serves or the network. Except for Wi-Fi, each IoT connectivity solution is designed to meet this requirement.

Security

Multiple types of security ranging from Advanced Encryption Standard (AES) encryption to high levels of authentication are in use in IoT devices. The reality is that each type of communication network is, on some level, vulnerable. This will be even more challenging when tens of thousands of sensors define a single network. All participants in IoT development are working toward providing greater end-to-end security.

Simplicity and Low Cost

Hardware is coming down in price, and more resources are available to help designers enable connectivity. Every silicon vendor now provides an impressive array of tools that allows the incorporation of their products into a system with low difficulty. Complete ecosystems also exist, which range from design resources to complete system descriptions, incorporating virtually all major considerations. The cost of IoT devices is rapidly declining as volumes increase.

IPv6 Capability

Internet Protocol Version 4 (IPv4) is the technology that enables devices to connect to the web. Used since 1983, it has now run out of public IPv4 address blocks globally. Europe’s Regional Internet Registries (RIRs) Réseaux IP Européens (RIPE) associated its last block. IPv6 will provide enough global address blocks for a long time, but implementing it rather than IPv4 in each IoT system is not simple. Requiring significant changes to many types of software and exchanging data between these protocols depends upon special gateways. All current connectivity solutions either natively employ IPv6 or can be configured to do so.

Major IoT Connectivity Solutions Compared

The major connectivity solutions available today are shown in Table 1. Wi-Fi, in existence longer than other short-range technologies, is fundamentally different. It was never intended to deal with tiny, power-stripping devices like IoT sensors, as the goal was to provide high-speed data and replace wired networks. Wi-Fi is power hungry and depends on fairly expensive components. However, its throughput ensures its appeal as an adjunct to connect low-power solutions, such as video surveillance to the Internet.

Table 1: Most common short-range IoT connectivity solutions.

Wi-Fi, Zigbee, Z-Wave, and Bluetooth are further along in their development than others, and Zigbee is in use by most IoT applications. Thread is increasing in popularity with nearly 100 members, while ANT+1 is somewhat popular in Europe. However, a complete discussion of IoT connectivity requires mention of competitors that are typically dedicated to specific use cases.

EnOcean

A spin-off from Siemens, EnOcean GmbH is located in Germany and its wireless modules are built and marketed by the company. EnOcean-based modules combine microenergy converters and ultra-low-power electronics, enabling communications between battery-less wireless sensors, switches, controllers, and gateways. It has a range of 300m in free space, data rates below 125kbps, and optimizes the amount of power required to transmit a given amount of data. EnOcean operates at 902, 928.35, 868.3, and 315MHz depending on the country.

Insteon

This solution from Smartlabs allows IoT devices to communicate wirelessly or through power lines in a dualband-type of mesh networking and is compatible with the X10 wired network standard. It has considerable industry support from companies like Apple, Microsoft, Amazon, Logitech, and others. Its maximum sustained data rate is 180bps, free-space range is up to about 45m, and operating frequency is 902 to 924MHz.

Microchip Wireless Networking (MiWi)

This Microchip-proprietary protocol is based on the 802.15.4 standard, operates at 2.4GHz or below 1GHz, is compatible with Zigbee, and can be configured in star, cluster, mesh, and tree network topologies.

Wireless Highway Addressable Remote Transducer (WirelessHART) Protocol

Designed to serve process field device networks in process automation, this open standard that the HART Communication Foundation developed uses a time-synchronized, selforganizing, self-healing mesh architecture. It operates at 2.4GHz using 802.15.4 radios.

Changing the IoT Home Automation Landscape

Given Wi-Fi’s power-hungry nature and low data rates of the popular Z-Wave, Zigbee, and Thread, Bluetooth 5.0 is rapidly stepping up to be a game changer. The latest 4.0 and 4.2 versions of the Bluetooth Low Energy (BLE) standards double the maximum data rate to 2Mbps while increasing distance four times to 120m. It also adds mesh networking capabilities, freeing Bluetooth to become a major player in IoT home automation connectivity.

One specific benefit is that it’s already a widely used, short-range, global solution and is integrated into smart televisions, gaming consoles, speakers, headsets, and smartphones. An important feature is its beaconing capabilities. Extremely small and inexpensive beacons can be deployed virtually anywhere. The short-range transmitters deliver short messages to smartphones with a beaconing app installed. The Bluetooth phone receiver receives messages and notifications are delivered to the user. Any barriers to its use have been removed in Bluetooth 5.0.

In addition to Bluetooth’s short range, beacons can send only very short messages—too short to deliver long URLs—and even though beaconing doesn’t require authentication (as beacons transmit but don’t receive data), without mesh networking large groups of beacons are not configurable. All of this is rectified in Bluetooth 5.0, so it’s likely that beacons will be more widely deployed and promoted, and more applications will make use of them.

ABI Research and IHS Research both predict Bluetooth 5.0 and its IoT-bolstering capabilities will reach five billion by 2021 and three billion by 2017, respectively.

Another highlight is the IPv6 over Low-power Wireless Personal-Area Network (6LoWPAN). Standardized in 2003, 6LoWPAN has demonstrated some significant advantages over Zigbee, Z-Wave, and other options: Notably, it operates with any solution based on 802.15.4 using a very simple bridge or with any devices within an Internet Protocol (IP)-based network such as Bluetooth or Ethernet. To compete, Zigbee and Z-Wave need complex application layer gateways.

With 6LoWPAN, every node in the network has its own IPv6 address, freeing the network to connect to the Internet using open standards. IPv6 and Bluetooth are the new players to watch as IoT evolves in the coming years.

Challenges IoT System Manufacturers Face

Although 6LoWPAN solves the competing standards issue, home automation designers are still faced with a selection challenge: That is, what components and systems will maintain longevity as new solutions come into the marketplace at breakneck speed? Ultimately, all new home automation solutions should address both mains-powered and battery-powered devices, should be manufacturer and product agnostic, and should communicate using narrow and wide bandwidths. Not only should these solutions address concerns regarding constant and consistent updates but also regarding the potentially long line of legacy solutions that will need support.

What’s Happening Now?

Today, and for many years to come, home automation manufacturers will use multiple connectivity solutions in their products. In fact, it’s likely that the number will rise rather than fall in the near future. The winners in this dilemma will be manufacturers of IoT radios, RF front ends, and controllers that support multiple standards. Likewise, smart designers will need to employ a single device or set of devices that support multiple product lines while simultaneously future-proofing their offerings.

With all that said, the fact remains that design and manufacturing will ultimately become more complicated as selection, configuration, and interoperability attempt to address the fragmented IoT landscape.

Carolyn Mathas is a freelance writer/site editor for United Business Media’s EDN and EE Times, IHS 360, and AspenCore, as well as individual companies. Mathas was Director of Marketing for Securealink and Micrium, Inc., and provided public relations, marketing and writing services to Philips, Altera, Boulder Creek Engineering and Lucent Technologies. She holds an MBA from New York Institute of Technology and a BS in Marketing from University of Phoenix.