Z-Wave’s interoperability layer ensures that devices can share information and allows all Z-Wave hardware and software to work together. Its wireless mesh networking technology enables any node to talk to adjacent nodes directly or indirectly, controlling any additional nodes. Nodes that are within range communicate directly with one another. If they aren’t within range, they can link with another node that is within range of both to access and exchange information.
In September 2016, certain parts of the Z-Wave technology were made publicly available, when Sigma Designs released a public version of Z-Wave’s interoperability layer, with the software added to Z-Wave’s open-source library. The open source availability allows software developers to integrate Z-Wave into devices with fewer restrictions. IP for transporting Z-Wave signals over IP networks, and Z-Ware middleware are all open source as of 2016. The Z-Wave Alliance was established in 2005 as a consortium of companies that make connected appliances controlled through apps on smartphones, tablets or computers using Z-Wave wireless mesh networking technology. The alliance is a formal association focussed on both the expansion of Z-Wave and the continued interoperability of any device that utilises Z-Wave. In February 2014, the first product was certified by Z-Wave Plus.
The alliance aims to create for the smart home a secure mesh network that works across different platforms. Z-Wave is designed to achieve reliable communication and operation between devices and sensor-enabled objects from various manufacturers in the Z-Wave Alliance, which consists of over 450 members. 42 MHz in Europe, at 908. 42 MHz in the North America and uses other frequencies in other countries depending on their regulations. 9959 and fully backwards compatible. Z-Wave PHY and MAC layers as an option in its G. 9959 standard for wireless devices under 1 GHz.
In such networks, devices use the wireless channel to send control messages which are then relayed by neighboring devices in a wave-like fashion. The source device wanting to transmit is therefore known as the initiator. Hence, the name source-initiated mesh ad hoc routing. There were several source-initiated mesh routing protocols proposed in the period early 1990s. A message from node A to node C can be successfully delivered even if the two nodes are not within range, providing that a third node B can communicate with nodes A and C. If the preferred route is unavailable, the message originator will attempt other routes until a path is found to the C node. The simplest network is a single controllable device and a primary controller.
Additional devices can be added at any time, as can secondary controllers, including traditional hand-held controllers, key-fob controllers, wall-switch controllers and PC applications designed for management and control of a Z-Wave network. A device must be «included» to the Z-Wave network before it can be controlled via Z-Wave. This sequence only needs to be performed once, after which the device is always recognized by the controller. Devices can be removed from the Z-Wave network by a similar process. The controller learns the signal strength between the devices during the inclusion process, thus the architecture expects the devices to be in their intended final location before they are added to the system. The controller is then returned to its normal location and reconnected. Each Z-Wave network is identified by a Network ID, and each device is further identified by a Node ID.
Nodes with different Network IDs cannot communicate with each other. The Node ID is the address of a single node in the network. 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. With Z-Wave mesh networks, each device in the house bounces wireless signals around the house, which results in low power consumption, allowing devices work for years without needing to replace batteries. For Z-Wave units to be able to route unsolicited messages, they cannot be in sleep mode. Therefore, battery-operated devices are not designed as repeater units. Mobile devices, such as remote controls, are also excluded since Z-Wave assumes that all devices in the network remain in their original detected position.
Z-Wave is based on a proprietary design, with Sigma Designs as its primary chip vendor. In 2014, Mitsumi became a licensed second source for Z-Wave 500 series chips. Z-Wave protocol stack layers, requiring the design of a radio packet capture device and related software to intercept Z-Wave communications. An early vulnerability was uncovered in AES-encrypted Z-Wave door locks that could be remotely exploited to unlock doors without the knowledge of the encryption keys, and due to the changed keys, subsequent network messages, as in «door is open», would be ignored by the established controller of the network. The vulnerability was not due to a flaw in the Z-Wave protocol specification but was an implementation error by the door lock manufacturer. On November 17, 2016, the Z-Wave Alliance announced stronger security standards for devices receiving Z-Wave Certification as of April 2, 2017. The new layer of authentication is intended to prevent hackers from taking control of unsecured or poorly secured devices. According to the Z-Wave Alliance, the new security standard is the most advanced security available on the market for smart home devices and controllers, gateways and hubs. With a power supply of 2. 6 volts, it consumes 23mA in transmit mode. Its features include AES-128 encryption, a 100kbps wireless channel, concurrent listening on multiple channels, and USB VCP support. For smart-home wireless networking, there are numerous technologies competing to become the standard of choice. Insteon has the largest number of maximum devices capability at 17.