Skip to main content

Passive Wi-Fi could improve battery life and power the IoT

Researchers at the University of Washington have found a way to lower the power consumption of Wi-Fi significantly. They have dubbed their new form of low power wireless internet 'passive W-F' and it could be harnessed to power IoT devices or to help improve battery life in mobile phones.

Passive Wi-Fi will require just 59 microwatts to transmit data between devices which is 10,000 times less than the power used by traditional Wi-Fi chips in personal computers and mobile phones.

However, there is a catch. Wireless routers and the devices they are sending passive Wi-Fi to will need new chips to make use of the technology which is still quite a number of years away from a consumer release. A spin off company called Jeeva Wireless has been created to help push the commercialisation of this new form of Wi-Fi.

Currently, wireless routers and wireless devices have chips that allow them to send and receive data over Wi-Fi. Passive Wi-Fi works by replacing the wireless chips in our devices with new ones that are able to act like mirrors that can reflect the wireless data back to our routers. This allows the devices to save the energy they would normally send broadcasting their own signal back to the router.

The reflected data is able to reach a speed of 11Mbps or the speed of 802.11b Wi-Fi. The researchers at the University of Washington have been able to transmit data between 30-100 feet using this new technology. Passive Wi-Fi is also able to broadcast using line of sight or even through walls if necessary.

One possible flaw is that since it is a passive signal it is unable to actively alert a router that it is ready to send and receive data. To function, the router will need to give a command to the devices in order to enable them to send data at a certain time or when a certain condition is met.

Wi-Fi has become commonplace in many homes and offices over the past few years and a new passive form of wireless internet may reinvigorate interest in how businesses and consumers can make use of the technology in new ways.

Image Credit: Pior Adamowicz (opens in new tab) / Shutterstock (opens in new tab)

Anthony Spadafora
Anthony Spadafora

After getting his start at ITProPortal and then working with the TechRadar Pro team for the last several years, Anthony is now the security and networking editor at Tom’s Guide where he covers everything from data breaches to how to cover your whole home or business with Wi-Fi. When not writing, you can find him tinkering with PCs and game consoles, managing cables and upgrading his smart home.