Sensors Everywhere—The New Smart, Connected HomeApril 26, 2013 By: Cees Links, GreenPeak
The new smart connected home is finally becoming a reality. For many years pundits have been announcing the arrival of the smart home that can sense movement, temperature, location, and health emergencies and respond to the stimulus. What has taken so long? Two challenges have held back the connected home. The first was the lack of a standardized communication protocol and the second was the marketing muscle to make the connected home happen.
Although numerous sensing devices and systems have been developed for the home, they have been limited in their scope. Many of them couldn't communicate with each other, with a central control box, or be controlled via the Web in a unified and efficient manner. They were either hard-wired to the device they controlled or were monitored by a local wireless remote.
The emergence of ZigBee (IEEE 802.15.4) wireless for the home has provided device manufacturers and application developers a standardized, open protocol to design and market connected home devices that will all talk to each other over the ZigBee protocol. Millions of radio chips based on this wireless standard, from a dozen or more chip makers, are now being sold every week into the marketplace.
ZigBee is very similar to Wi-Fi (802.11x) in regards to how it works, its range, its security protocols, and its frequency bands. The big difference lies in the two protocols' data rates and power consumption. Because Wi-Fi is designed to transmit at high data rates—many megabits per second—it is ideal for transmitting content such as movies, music, games, and even voice throughout a home. However, Wi-Fi is notorious for using a lot of (battery) power. In contrast, because ZigBee was designed as a low data-rate protocol, it only needs to send a few bits every few seconds. Its limited bandwidth means that its power demands can be a tiny fraction of the power needed for Wi-Fi.
In many home sensor applications, a tiny watch battery can power the ZigBee radio for over ten years before it needs to be replaced or recharged, a time-span that is much longer than the life of most sensor devices! In some cases, certain types of sensors can use the newly announced ZigBee Green Power profile to operate using energy harvesting rather than batteries. For example, light switches (a type of sensor) can generate enough power from the movement of the switch itself to transmit a signal across the room to turn on a light.
Because ZigBee is an open and universal standard and many different chip makers are making the basic ZigBee wireless radios, device developers can now create a plethora of smart home sensors and devices with the confidence that all of the sensor nodes are both compatible and interoperable.
Several years ago, the leading ZigBee manufacturers thought that the prime mover for broader ZigBee use would be the consumer electronics industry. In fact, Panasonic, Phillips, Samsung, and Sony initially banded together and established ZigBee RF4CE, the de-facto standard for most of today's connected home sensors. However, now the cable companies and internet service providers are the ones primarily promoting the ZigBee smart connected home.
These operators are adding connected home services to their existing four plays of service: 1. TV & movies; 2. broadband connectivity; 3. VoIP; and 4. selling cellular phone service. Now we have the Fifth Play; the world of connected home services. The set top box makers—the suppliers for the cable industry, are gobbling up millions of ZigBee chips to put into their new generations of set-top boxes, rebranded as Home Control Boxes.
The cable companies and service providers visualize the smart, connected home as a network of sensors, switches, and actuators, all of which are connected to, and talking to each other via, the set-top box. This smart connected network can be controlled locally via wireless remotes, or (because the set top box is connected to the Web) can be controlled by any Web-connected device such as a smartphone or tablet.
The operators can increase their revenues and reduce the loss of their subscribers by providing new reasons and services for their customers to stay connected. In the United States, many cable companies are already actively marketing home services such as home security, health care management, and energy monitoring.
Once the consumer has the basic ZigBee connected home set-top box in their home, they can go out and purchase additional ZigBee sensor devices and systems at the their local home improvement or warehouse stores, bring them home, and install them wherever needed. If you enjoy Wi-Fi today: wait until you see ZigBee!
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