Imagine having the power to create the perfect lighting ambience at home with just one click of a button; picture having the power to adjust your window shades with only one touch to your iPhone. Such conveniences, without a doubt, sound appealing - but numerous home owners are wondering about the same questions: What do I need? Where do I begin? The answer to their concerns can be found within the open wireless standard.
“Home automation” (aka “home control”) is the use of intelligent devices that are interconnected to one another enabling remote control and monitoring of said devices. Such systems include but are not limited to: lighting, heating, entertainment, and safety. In establishments such as apartments, homes, or corporate buildings, plenty of leeway exists for possible improvements in both comfort and safety. Energy resources such as gas, oil, and electricity can find feasible means of better efficiency.
Driven by spiraling energy costs, demographic changes, and the increasing need for support and convenience in today's home environment, home automation has made its way amongst today's growing markets. With this breakthrough, planners, engineers, in addition to downstream users must maintain an overview on the wide array of providers and solutions available in the market as there are various forms of home networking used to create an automated or “intelligent” home.
Fig. 1: Many electrical functions in the home are are subject for central control logic.
The quest for an international standard
A fact that is frequently ignored is that communication networks only function if all the equipment in the network complies with the predefined rules or standards. There are two different approaches to this issue: Either all the equipment comes from a single manufacturer who ensures that their products are interoperable - otherwise known as the “closed standard," or all the equipment manufacturers are obliged to comply with these special rules - otherwise known as the “open standard."
From a consumer's perspective, the open standard is most advantageous because the market usually provides a greater selection of products at better prices. Looking at a company perspective, an open standard is indeed beneficial because it encourages market growth. Companies themselves can also exploit synergies by focusing on the products in which they specialize- while understanding that others supply complimentary and interoperable products.
The lack of an affordable, internationally recognized standard for home equipment communication has been one of the major problems for the home control sector. In Germany, the wired system KNX standard (formerly installation bus) has established itself. It certainly works very well and very reliably, but it is also very expensive.
Moreover, as this standard is a wired solution, KNX can only be effectively implemented in new build properties because precise planning is required in order to be able to arrange all the necessary lines and cables in the walls of a building during the construction period. Therefore, this solution is rarely used for renovations or leased apartments.
On the flip side, there are a range of closed standard wireless connection protocols; however, the decision is in favor of the traditional electrical installation method because it is less costly. In order to promote the large market for modernization and conversion, there is a need for affordable wireless-based products in which both professional installation engineers and informed end-users can install with ease and without major expense.
Open to everything
Accordingly, a general and internationally recognized open standard is needed for wireless communication. This is where the previously described conceptual approaches- closed versus open- conflict again. As mentioned before, the open standard has crucial benefits. Using open Z-Wave technology as a concrete example, we can show how a stable network can be produced under the conditions of an 868 MHz frequency band.
Z-Wave was developed by the Danish company Zensys, which was then acquired in 2008 by the USA-based semiconductor manufacturer Sigma Designs. The goal was simple: define a sound protocol, open it to the public, and place it in the hands of an industry alliance for further development. The result: Z-Wave's basic physical and media access control layers (PHY/MAC) have become a certified international standard by the International Telecommunications Union as ITU-T G.9959.
The Z-Wave Alliance and its member companies maintain the upper layers of the communications standard, its development, application, and final product certification requirements. Sigma Designs and Mitsumi Corporation supply the communication modules with the complete protocol stack to various partners (OEMs), who then integrate the technology into their own products and launches these to the market.
Fig. 2: Z-Wave communications modules are implementations of the complete protocol stack.
Independent test laboratories certify product adherence to the standard ensuring interoperability. Only certified equipment can be sold as Z-Wave equipment.