According to strategy analytics, an average of 2.4 devices per household were networked in 2008 - by 2015 this figure had already risen to 8.6. Gartner forecasts over 500 smart devices per household by 2022. Germany is one of the most important markets: As the Smart Home Monitor 2016 issued by the Dr. Grieger & Cie. market research institute and the SmartHome Initiative Deutschland e.V. found out, that around 30% of the 1017 households in the survey are already using smart home applications, especially in the areas of energy management, entertainment and communication, as well as for security solutions. But Smart Home and Ambient Assisted Living (AAL) technologies are not only making progress in the context of private ownership. Property management companies and housing associations are increasingly using solutions for consumption monitoring and invoicing, as well as heating control systems that regulate the interior climate and help to prevent the formation of mold. Various wireless standards and platforms have been developed to provide for application networking.
Proprietary alternative from the USA: Z-Wave
In the USA, one occasionally comes across the Z-Wave meshed network protocol provided by the US-American company Sigma Designs. As no other semiconductor suppliers use this protocol, many device manufacturers are wary of finding themselves in a dead end. In America, Z-Wave uses the license-free frequency of 915MHz. As this frequency is not available in Europe, suppliers of Z-Wave compatible end devices must resort to using 868MHz transceivers. Other disadvantages of Z-Wave are the low data transfer rates and lack of compatibility with smartphones. This represents a decisive factor, for most users want to be able to operate the Smart Home functions remotely, and preferably via smartphone. This was established by the Deloitte Smart Home Survey 2015.
Flexible frequency selection: ZigBee
ZigBee is another meshed network protocol that, up to now, has mainly been used in the USA. It is based on IEEE 802.15.4. ZigBee uses the 2.4GHz frequency, also license-free, and sub-GHz frequencies. This means that users can select the best frequency for each Smart Home application, especially if they implement a sub-GHz / 2.4GHz combo-transceiver such as Atmel's AT86RF215. However, ZigBee cannot be recommended at present: In 2015 a serious security loophole was discovered, and to date it has not been possible to rectify this by means of firmware updates. However, this will change in the near future: The ZigBee consortium is already testing the 3.0 specification that closes the loophole.
Versatile and safe: Thread
Also based on the IEEE 1802.15.4 protocol for sub-GHz and 2.4GHz is the Thread network. It has the reputation of being very robust, self-healing and energy-saving, and with IPv6 support it is the 6LowPAN alternative to Bluetooth and WiFi. The AES encryption ensures security. As Thread is license-free, it is already being used by a large group of 220 supporters, including ARM, Samsung, Atmel, Procter &Gamble, and Osram. The popular modules supplied by Redpine Signals that are based on the current RS9113 M2M Combo chipset also support the Thread protocol, in addition to dual band WiFi (2.4/5GHz), Bluetooth classic, Bluetooth Low Energy and ZigBee.
High-profile throughout the world: Bluetooth Smart
Bluetooth Smart (also Bluetooth Low Energy (BLE)), that also uses the 2.4GHz band, is used a great deal across the globe. BLE, too, has the decisive advantage of IPv6 support that allows end devices to be addressed directly via an IPv6 address. Nordic Semiconductor is already supplying software stacks for this in its nRF51 SoC (Cortex M0 + 2.4GHz transceiver) and nRF52 SoC (Cortex M4 + 2.4GHz transceiver + NFC). Also, BLE is a step ahead of the competition thanks to its widespread use in smartphones. Practically all models have a BLE interface that allows them to communicate directly with BLE Smart Home products. In addition, the BLE standard 5.0 has brought improvements in range, data transfer rates and broadcasting capability. The latter feature makes apps superfluous when it comes to connecting with end devices and sending data to the cloud, which results in a connection independent Internet of Things. Furthermore, for 2017 experts are expecting a Bluetooth Smart meshed network protocol for which Nordic will certainly have a suitable software stack available for its nRF51 and nRF52.
From the gym into the smart home: ANT
Another protocol that should not be left out of account is ANT. ANT was developed by the Garmin subsidiary Dynastream, and so far it is generally known for its use in connection with sports equipment. However, ANT has now found its way into the areas of home automation, indoor locating and telemedicine. Like Z-Wave, ANT is a proprietary protocol, but it has the advantage of being supported by several semiconductor manufacturers providing more reliability to customers. Thanks to its low energy consumption, high degree of flexibility in respect of network topology and the increasing number of smartphones with ANT support, it is definitely emerging as an alternative to the other standards that should be taken seriously. Nordic also provides an ANT software stack for its nRF51 and nRF52 SoCs.
At home (nearly) everywhere: WLAN
WLAN is of great significance for the smart home. It is already present in many houses and apartments, allowing for high data transfer rates that are especially important for surveillance cameras and multimedia applications. However, Smart Home applications from the areas of energy management and Ambient Assisted Living also use WLAN as their wireless standard, whether for direct communication with a smartphone or to send data into the cloud via the local network. WLAN and BLE are often used in combination, especially for sending sensor data via BLE to a central unit and then into the cloud via WLAN. In such cases, combination modules such as the RS9113 from Redpine Signals are most suitable. The latest sub-GHz WLAN standard 802.11ah also ensures that WLAN will remain state-of-the-art for the Smart Home in the foreseeable future.
At present, it is not possible to predict which wireless standard will come out on top. There are good reasons to expect that no single standard will emerge to the exclusion of all others, but that several will coexist. In this case, centralized connectivity units will provide for compatibility, or individual suppliers will develop proprietary, clearly demarcated Smart Home systems.
At all events, the decisive criteria that will drive success are IPv6 support, smartphone compatibility and flexibility in order to be able to quickly respond to new requirements. The ANT protocol fulfills all of these demands, so it will certainly be able to acquire a larger share of the market. But the heavyweights Bluetooth Low Energy and WiFi are also excellently placed to defend their positions on the market for a long time to come.