A tropical paradise both beautiful and smart

Stunning coastlines and verdant mountain scenery make the Cook Islands a popular tourist destination. This tourism industry has contributed to a decade of economic growth, and in 2021 the government of this nation in the South Pacific introduced the SMART Economy Initiative to create ‘smart’ island networks.

Around the world, the Internet of Things (IoT) is used for energy metering, road traffic management, street lighting operation and environmental controls. Not all IoT nodes need the fast data transfer of a 5G network, and in the Cook Islands, the tropical and mountainous terrain means installation is not practical.

LoRaWAN (long-range wide area network) technology was selected for the Cook Islands’ Smart Island project. The low-power protocol uses the unlicensed industrial, scientific, and medical (ISM) frequency band for bi-directional communication. It has a range of 5-7km in rural areas and transmission speeds are up to 27kbit/s. This is less quick than 5G but sufficient for transmitting non-​mission-critical data such as water tank levels, or air quality, for example. The technology is suitable for handling small packages of data, such as light levels, temperature, humidity or soil moisture levels in agriculture and its low-power operation means that batteries in networked devices can last for 10 years.

The islands have different landscapes. The largest, Rarotonga, has central mountains with valleys while others are coral atolls. “We installed Yagi antennas [directional antennas, like TV aerials, connected to a radio transmitter and/or receiver through a transmission line] to provide coverage for more remote areas,” says Michael Welzel, CTO of IQnexus.

“Vegetation and large trees are another challenge,” he continues. “In some cases, they are worse than large buildings, because a tree is not reflecting radio waves.”  

The Cook Islands’ government awarded a grant to ICTnexus, the Rarotonga-based ICT and IoT network provider, to set up a LoRaWAN in the two largest islands. The company was set up in 2019 as part of the Smart Economy Grant to improve the islands’ infrastructure.

“The Cook Islands became a testbench for the Smart Island concept,” explains Welzel. New Zealand-based IQnexus, a partner for ICTnexus, has supplied sensors equipped with LoRa technology and transceivers based on the ModBus data communications protocol for the project.

One of the challenges for the Smart Island is that devices have to operate in direct sunlight at temperatures that can reach up to 60°C or in up to 100 per cent relative air humidity. They also have to withstand heavy tropical rain and wind. Some are subjected to corrosive coastal sea water content in the air or submersed in pits of sea water or grey water (household recycling water).

Other hazards are posed by spiders, ants and termites building nests in inconvenient places, or birds or insects covering small solar cells with their homes or debris, causing them to fail as a power source. Shelters, sun covers or IP67/IP68 plastic enclosures and junction boxes were installed to protect many of the sensors and transceivers.

To date, LoRaWAN has been introduced in the largest, most populous island, Rarotonga (population 10,000) and the second largest, Aitutaki (population 2,000). In addition, all the gateways have been installed in the smaller islands of Rakahanga and Manihiki, and Rarotonga and Aitutaki have 70 per cent and 50 per cent coverage respectively. Rarotonga houses 10 main outdoor gateways, supported by femto and pico gateways, with additional gateways on hillside sites. Aitutaki was more straightforward, says Welzel, with three gateways covering 9km line of sight. Installation across all islands is expected to be completed by the end of 2023.

ICTnexus and IQnexus will also work with semiconductor company Semtech, whose LoRa technology provides the physical radio layer for the long-range communication link in the LoRaWAN specification. Together they will develop purpose-built LoRa networks for the archipelago of outer islands.

“Implementing LoRa allows for many use cases throughout the islands,” says Marc Pegulu, vice president and general manager for Semtech’s Wireless and Sensing Products group. The low-power, long-range capability of LoRa technology connects all IoT-enabled devices for applications across the islands’ power grid, utility meters as well as a variety of sensors for the water treatment plant and wastewater monitoring. A management platform will let operators view live data.

Specific applications are smart metering, water infrastructure and network, power-grid monitoring, streetlights, energy management, wastewater monitoring, air quality (indoor and outdoor), temperature monitoring, air-conditioning and HVAC monitoring and control, solar and renewable monitoring, like EV charging, environmental warning systems and tracking and tracing.

The IoT Smart Island services will provide real-time actionable data, adds Pegulu, and will free the islands from “nearly non-existing cellular M2M communication”.

The Smart Island project will provide citizens with clean water and reliable energy, but also fight climate change and protect the environment, says Pegulu. “Air quality and temperature/humidity measurements and LoRaWAN-connected power/energy meters are the fundament for successful energy management on the islands,” he says. In addition to ensuring clean water and reliable energy, it will help prevent ecological spillage of wastewater to protect the environment.

Commenting on the Smart Economy Initiative, Tai Kauraka Tangaroa, ICTnexus’ CEO, says “Our ultimate goal is to create a smart and sustainable island and help preserve our natural environment for our children.”

“LoRa will play a large role for energy and demand management and in the journey for sustainable, diesel-free generation of power and the monitoring and management of resources like electricity and water,” Pegulu believes.