Z-Wave is a wireless communications protocol used primarily for residential and commercial building automation.

[3][5] Z-Wave provides the application layer interoperability between home control systems of different manufacturers that are a part of its alliance.

[16] The technology began to catch on in North America around 2005, when five companies, including Danfoss, Ingersoll-Rand and Leviton Manufacturing, adopted Z-Wave.

[12][18] As part of the changes, the trademark interests in Z-Wave were retained in the United States by Sigma Designs and acquired by a subsidiary of Aeotec Group in Europe.

[19][20] On January 23, 2018, Sigma announced it planned to sell the Z-Wave technology and business assets to Silicon Labs for $240 million,[21] and the sale was completed on April 18, 2018.

[24] The open-source availability allows software developers to integrate Z-Wave into devices with fewer restrictions.

Z-Wave Alliance is a consortium of over 300 companies in the residential and commercial connected technology market.

[5][11][26][27] In October 2013, a new protocol and interoperability certification program called Z-Wave Plus was announced, based upon new features and higher interoperability standards bundled together and required for the 500 series system on a chip (SoC), and including some features that had been available since 2012 for the 300/400 series SoCs.

Instead of being a single-source specification, it will become a multi-source, wireless smart home standard developed by collective working group members of the Z-Wave Alliance.

[35] The Z-Wave Alliance would become a standards development organization (SDO), while continuing to manage the certification program.

[36] In August 2020, the Z-Wave Alliance officially became incorporated as an independent nonprofit standards development organization, with seven founding members under its new SDO structure: Alarm.com, Assa Abloy, Leedarson, Ring, Silicon Labs, StratIS, and Qolsys.

[41] Z-Wave uses the Part 15 unlicensed industrial, scientific, and medical (ISM) band,[42] operating on varying frequencies globally.

In 2012, the International Telecommunication Union (ITU) included the Z-Wave PHY and MAC layers as an option in its G.9959 standard for wireless devices under 1 GHz.

[45] Z-Wave LR devices operate on a star network topology that features the hub at a central point and then establishes a direct connection to each device, rather than sending signals from node to node until the intended destination is met, as in a mesh network.

Devices can communicate to one another by using intermediate nodes to actively route around and circumvent household obstacles or radio dead spots that might occur in the multipath environment of a house.

Therefore, a Z-Wave network can span much farther than the radio range of a single unit; however, with several of these hops a slight delay may be introduced between the control command and the desired result.

The controller learns the signal strength between the devices during the inclusion process and will utilize this information when calculating routes.

In the event that devices have been moved and the previously stored signal strength is wrong, the controller may issue a new route resolution through one or more explore frames.

[47] The Z-Wave chip is optimized for battery-powered devices, and most of the time remains in a power saving mode to consume less energy, waking up only to perform its function.

The vulnerability was not due to a flaw in the Z-Wave protocol specification but was an implementation error by the door-lock manufacturer.

The new layer of authentication is intended to prevent hackers from taking control of unsecured or poorly-secured devices.

In 2022, researchers published several vulnerabilities in the Z-Wave chipsets up to the 700 series,[54] based on an open-source protocol-specific fuzzer.

[57] The chip for Z-Wave nodes is the ZW0500, built around an Intel MCS-51 microcontroller with an internal system clock of 32 MHz.

[8] It enables a new class of smart home devices that can be used outdoors, with a range of up to 300 feet, and that can operate on a coin-cell battery for up to a decade.

[8] The specification supports a maximum output power of 30 dBm, which can be used to bolster transmission range by up to several miles.

In testing, Z-Wave LR had a transmission distance of 1-mile (1.6 km) direct line of sight utilizing +14-dBm output power.

[60] Z-Wave LR operates on low power so that sensors can last for 10 years on a single coin cell.

It is described as secure, ultra-low powered, and wireless, for Internet of Things devices, with an improved battery life as compared to the 700 series.

[62] OpenZWave is a library, written in C++ and wrappers and supporting projects, to interface different languages and protocol(s) allowing anyone to create applications to control devices on a Z-Wave network, without requiring in-depth knowledge of the Z-Wave protocol.