World's First Radio Devices to Support Wi-SUN Profile for HAN

February 13, 2015

Abstract

NICT has developed the world's first radio devices that support the Wi-SUN profile for HAN (Home Area Network). The Wi-SUN Alliance has recently finalized the Wi-SUN certification specification for HAN that provides radio connectivity between a HEMS (Home Energy Management System) controller and home appliances by deploying the 920 MHz radio links compliant with the IEEE 802.15.4g standard.

NICT has developed the radio devices that implement the specifications and successfully conducted the proof test of multiple appliance authentications by a HEMS controller with assumed relay transmission among those appliances.

Achievements

Figure 1: Outline of HEMS including HAN

NICT has developed the world’s first radio devices with a relay transmission feature that are compliant with the Wi-SUN profile for HAN.

Figure 1 shows an outline of HEMS. ECHONET Lite is dominantly deployed for the higher layer communication protocol among HEMS devices, such as a HEMS controller, a smart meter, home appliances and so on. Accordingly, the Wi-SUN Alliance has finalized the “Wi-SUN profile for ECHONET Lite” that defines the lower layer communication protocol using IEEE 802.15.4g compliant with 920 MHz radio.

While the previous version of the Wi-SUN profile defined only specifications for Route B: the radio link between the smart meter and the HEMS controller, the Wi-SUN Alliance has expanded the profile so that it defines specifications for HAN constructed by a HEMS controller and home appliances. The expanded profile suitably copes with the HEMS controller connections to the multiple home appliances that possibly require relay transmissions via relay devices.

Future prospects

NICT is continuously promoting research and development of Wi-SUN compliant devices, so that we could contribute to the realization of safe and secure society by ICT. NICT is also seeking an opportunity of technology transfer of the developed devices.

Appendix

Figure 1: Outline of HEMS including HAN

Figure 1 shows an outline of HEMS that includes HAN. In this figure, three home appliances are connected to the HEMS controller. And, one of those appliances cannot connect to the HEMS controller by the direct link owing to path loss, for example.

Figure 2: Wi-SUN profile for HAN

Figure 2 shows the Wi-SUN profile for HAN that is implemented this time. Compared with the profile for Route B, security mechanism and MAC function are enhanced in order to cope with the authentication of the multiple devices and to cope with relay transmission, respectively.

Figure 3: Proof test setup for Wi-SUN profile for HAN

Figure 3 shows the proof test setup for the Wi-SUN profile for HAN. HEMS controller is implemented by a laptop PC and a SUN device. As for the implementations of the two home appliances, a hair dryer with a smart tap (a tap with SUN radio capability) and an LED light with a SUN device are deployed as in Figure 3. Moreover, relay transmission by a relay device is assumed for the HAN radio link between the HEMS controller and the LED light, differently from the direct link between the HEMS controller and the hair dryer. By using the setup in Figure 3, it is confirmed that the amount of consumed power is periodically reported to the HEMS controller from the smart tap and that the HEMS controller can operate the LED light via the relayed radio link.

Glossary

Wi-SUN Alliance/ Wi-SUN profile

The Wi-SUN Alliance, established on January 24, 2012, is an organization that supports certification and promotion for radio devices for SUN (Smart Utility Networks) by assuming IEEE 802.15.4g standards adoption for low-power smart meter radio systems. NICT is one of the promoter members of the Wi-SUN Alliance.

The certifications by the Wi-SUN Alliance are revealed by the definition of the protocol stacks with PHY, MAC and higher layer specifications according to the assumed applications. Each of such stacks is called as the Wi-SUN profile for the application.

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HEMS (Home Energy Management System)

HEMS is a system concept that realizes power monitoring and required management of power usage based on the monitored results. HEMS is constructed by a smart meter, a HEMS controller, home appliances and so on, where the HEMS controller conducts a centralized control by connecting to other devices.

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IEEE 802.15.4g

IEEE 802.15.4g is a standard that defines the necessary PHY amendments in the existing IEEE 802.15.4 standard that are required in order to realize SUN. The latest version of the draft defines additional modulation schemes and frequency bands, and expanded data payload.

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ECHONET Lite

ECHONET Lite is a standard for the higher layer communication protocol for HEMS that is finalized by the ECHONET CONSORTIUM. It is also globally standardized as an ISO standard and an IEC standard and recommended as the domestic standard protocol for radio connections among the smart meter, the HEMS controller and home appliances by the Ministry of Economy, Trade and Industry (METI). Since the ECHONET Lite is defined as the protocol stacks consisting of 5^th, 6^th and 7^th layers as in OSI models, the Wi-SUN profile for that consists of 1^st to 4^th layers.

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