Do RF-based remote controls make "cents"?

(Editor's note: we're all familiar with the ubiquitous and widespread infrared-based (IR) remote-control. But in our world of advancements and innovation, RF-based remote controls--under the umbrella of RF4CE and Zigbee--are starting to provide an alternative with added features, though their cost is higher at this time. This article explores the situation and includes additonal resources at the end.)

RF-based remote controls have been around in the market now for several years. Whether purchased in the universal remote section of Best Buy or obtained as part of a custom home-theatre system to drive your 60" plasma screen and high-end multimedia components, the RF interactive experience has been something only users of top-tier equipment have been able to enjoy.

However, if RF-based remote-control technology takes off in 2010, the benefits of non-line-of-sight operation and two-way communication will become ubiquitous, available to almost anyone purchasing a new TV, set top box, or audio/video (A/V) components. RF provides very different capabilities when compared to IR, so the RF remote-control experience provides an opportunity for consumer electronics companies to differentiate themselves in increasingly competitive markets. First, though, they need to work out the dollars and cents.

Existing Infrared remotes that ship with a new TV, STB, DVD player, or other products cost a vendor approximately $2-$5, with the IR transmitter costing between $0.20 to $0.50 of the bill of material (BOM). No RF-based solution thus far can reach such aggressive pricing.

However, the cost of RF transceivers, often coupled with an MCU (SoCs), have continued to come down in price significantly (Moore's law, again). Despite costs that will not likely reach IR levels for another few years, at best, the question we need to be asking is not: "when will an RF solution achieve IR's cost point?"

Instead, it should be: "when will the value proposition of RF-based remote controls justify the increase in BOM cost?" The recent announcement by the ZigBee® Alliance of the new Radio Frequency for Consumer Electronics (RF4CE) standard (ZigBee RF4CE), originally conceived by founders Philips, Sony, Panasonic and Samsung, with technical contributions by Texas Instruments, Freescale and OKI, make the strong argument that this value proposition has been achieved, and the technology we seek is here today.

Although RF4CE is not the only solution for RF-based remote control technology, the fact that a consortium was formed by key consumer-driven companies to create a new RF remote control standard, and that has since been ratified and handed over to the ZigBee Alliance to manage and promote, provides some strong justification for betting on ZigBee RF4CE to dominate this market. ZigBee RF4CE is built on top of the IEEE 802.15.4 PHY/MAC and, thus, is rooted in a mature RF technology.

The RF4CE standard defines a controller (the remote control) and a target (your TV, STB or other CE device) that pair together in a simple and intuitive way, Figure 1.

Figure 1: ZigBee RF4CE Supported Topology
RF4CE also defines the networking layer and application profile or Consumer Electronics Remote Control (CERC) to ensure interoperability and provide for easy device setup, pairing, power management, and the issuing of simple and secure commands for control of consumer electronics devices, Figure 2.

Figure 1: Network Protocol Stack.
With RF-based remote control technology, there are several initial, fundamental benefits. Obviously, compared to conventional IR, RF operates without line-of-sight communication, over a much longer range, offers two-way communication, and has increased throughput. These technical enhancements map to an extensive number of benefits that the consumer will quickly notice the first time he/she sits down with an RF4CE-driven remote control.

One such enhancement is the ability to change channels or control your entertainment system without pointing your remote at the system, or to do so when your components are hidden behind cabinets or even outside of your TV room. Another is provided through acknowledged communication so that commands are verified and, if necessary, retransmitted to prevent the often frustrating need to re-press buttons when a TV or STB fails to respond. This is especially noticeable in universal remote controls where selecting a "scene" or multi-device configuration requires sending multiple commands to multiple consumer electronics devices. In the case where one or more of these commands is not received, your entire system can get "disoriented" (since IR provides no way of acknowledging the receipt of a command), and the result can be significant user frustration.

ZigBee RF4CE offers power savings on both the controller and target side, resulting in lower average power consumption on the target, something that has become increasingly important in the European market, and longer device lifetime (when compared to IR) on the controller side which means possibly using smaller batteries or increasing the longevity of a remote control. Additionally, RF-based remote controls offers further enhancements including more security, dynamic programming or re-programming of devices, added power-savings opportunities, simple intuitive pairing, robustness and reliability through the simultaneous use of multiple channels, and much more.

Beyond the basic benefits of RF, two-way communication offers the possibility of putting the remote control at the center of everyone's living room. Remote controls will allow enhanced navigation that can make interacting with your television more like browsing the web on your computer. Advanced menus, pointing capabilities (think of the Wii) and the ability to push data from your STB or TV to your remote will open up new possibilities and exciting business models we're only beginning to explore.

Using the bi-directional nature of IEEE 802.15.4, for example, an RF4CE-compliant universal remote control could "learn" commands that are not part of the core CERC profile defined by the ZigBee RF4CE specification. While interacting with a CD or MP3 player, the database of songs and artists can be displayed and navigated locally on the remote, allowing bulky components to be tucked away in a closet potentially far away from your living room. A buzzer feature triggered by a button on the TV or STB could be designed into the remote to allow you to locate the remote when your two-year-old becomes proficient at hide-and-seek.

In addition to the interaction of remote controls and consumer electronics devices, ZigBee RF4CE could become much more. Automated control of your home, although already available through technologies like ZigBee Home Automation, could become an integral part of remote control functionality. Home automation technology is only starting to come down in price and, with RF4CE-compliant devices arriving in tens of millions of homes through the sales of corresponding RF4CE-compliant TVs or STBs, we will see the proliferation of the necessary infrastructure to enable true home automation.

Lighting, temperature control, motor control of fans, windows and curtains, for example, could piggy-back on this new standard. It is not yet clear if RF4CE will be used for home automation, and it is important to note that the single, existing public profile, CERC, does not currently define or focus on home-automation (HA) devices outside of the consumer electronics space. Only time will tell how RF4CE grows and proliferates, so be alert and be ready for the next wave of innovation in your home.

Development kits such as Texas Instrument's CC2530 and associated protocol stack (can simplify project engineering and development. Using the off-the-shelf development kit, free stack software, sample applications, tools and easy-to-understand documentation, you can get started developing an RF4CE product for controller or target side, Figure 3, either directly on the system-on-chip device (e.g., CC2530), or on a microprocessor of choice, using a simple UART or SPI interface to the CC2530 running the ZigBee RF4CE stack. For lower-volume applications, there are quite a few module providers or original equipment manufacturers (OEM) that can get you up and running with a solution in no time as well.

Figure 1: RemoTI-CC2530DK ZigBee-RF4CE Development kit by TI
It is important, of course, that when considering an RF-based remote-control solution such as a ZigBee RF4CE-compliant solution for your product, to compare the cost of IR versus RF. Be sure that that you factor in the technical advantages of RF and RF4CE when making the comparison, as well as the ecosystem that will quickly emerge in this market. Ignoring RF-based remote controls to save money on your BOM might seem like a smart decision at the time. However, it could ultimately result in missed opportunity and growth for your product line.

References

• To learn more about ZigBee RF4CE, click here.
• For more information about the CC2530 and protocol stack, click here and here.

Related articles

• "Beyond-IR: Remote Controls for Home Entertainment", June 17, 2009
• "Wireless rivals vie to replace IR remote controls", April 29, 2009
• Spec-compliant RF remote controls emerge", April 6, 2009
• "RF in Action: Consumer remote controls", March 23, 2009
• "Signal Chain Basics (Part 24): Basic networking using the IEEE 802.15.4 PHY/MAC protocol", December 2, 2008
• "RF4CE vs IR: the next remote-control "battle"?", June 6, 2009

About the Author
Brian M. Blum is a ZigBee Product Marketing Engineer with Texas Instruments, where he is responsible for 802.15.4 and ZigBee Low Power RF product line. He received his Master's of Computer Science w/ focus on Wireless Sensor Networking from University of Virginia. In his spare time he enjoys rock climbing, volleyball, yoga and nature. Brian can be reached at lpw-pme-zigbee@list.ti.com.

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