Wireless Audio Frequently Asked Questions
1. How does Kleer achieve such low power consumption? The answer is in the architecture of our radio.
A conventional direct conversion or low-IF radio receiver requires an RF PLL and two signal paths (I-phase and Q-phase) each with a mixer, filter and ADC to convert the incoming signal to a baseband digital signal for further processing. |
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| Kleer’s sub-sampling radio receiver has only a single signal path and eliminates the RF PLL and mixers, substantially reducing the power consumption of the receiver. |
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2. What is your vision?
As storage capacities increase, Kleer envisions that the portable media player will become the personal media server for all digital content including music, video and images. A key element in the fulfillment of this vision is the ability to wirelessly stream stored content to a variety of associated devices including earbuds, speakers, video displays and photo frames, without having to deal with a mess of cables and connectors, and without significantly reducing the battery life of the player.
3. What is your product?
Kleer Audio LP is a line of wireless modules that combine high quality audio and robust ISM band coexistence with low power consumption to address the full range of audio market segments. The line is based on our patented sub-sampling radio architecture which has been developed from the ground up to communicate lossless CD-quality digital stereo audio over a robust 2.4GHz radio link, while achieving 10 times the battery life of a comparable Bluetooth solution. As a result, Kleer’s technology is the first on the market to enable the manufacture of small form factor battery-powered products, such as wireless earbuds, that can be used with home and automotive audio/video systems, as well as with portable audio/media players.
4. Do you support video as well as audio?
Yes. Kleer’s technology actually supports standard definition video while maintaining robust ISM band coexistence and the same industry-leading low power consumption as our audio applications. Primary video applications include streaming video from a portable media player to a larger display, or to another media player to enable multiple individuals to view the content.
5. Who are your key competitors?
Bluetooth is the key competition in the portable audio market.
6. How does your product compare to Bluetooth?
Bluetooth is a standard for relatively short-range general purpose data communications. Bluetooth has found initial market success in wireless voice headsets for mobile phones and is now trying to address stereo audio for mobile phones and portable audio players. Bluetooth solutions suffer from poor audio quality due to the use of lossy audio compression, poor ISM band coexistence performance, and high power consumption when carrying streaming audio. Kleer’s patented sub-sampling radio architecture combines lossless audio transmission, lowpower consumption, and best-in-class ISM band co-existence to provide far superior audio quality with 10 times the battery life of a comparable Bluetooth solution.
7. What specific Bluetooth applications are you competing against?
Wireless stereo audio.
8. How do you substantiate your claim of 10 times the battery life of a comparable Bluetooth stereo audio solution?
Measurements on Bluetooth 1.2 and 2.0 stereo audio headphones available on the market today show power consumption of approximately 150mW. Kleer’s power consumption is less than 30mW which is a factor of 5 times less. However, this is not an apples-to-apples comparison because Kleer is carrying 3-4 times the data rate. Bluetooth uses lossy compression to reduce the audio data rate to 350Kb/s whereas Kleer carries the full 1.4112Mb/s. This is why Kleer’s audio quality is so much higher. Kleer estimates that a Bluetooth solution carrying 1.4Mb/s streaming audio would consume at least 300-400mW and this is the basis of our claim.
9. How do you guarantee high-fidelity stereo audio?
Our technology uses lossless transmission of 16-bit, 44.1KHz-sampled stereo audio to deliver full CD-quality audio.
10. Why is lossless transmission important when most of the content on portable audio players is compressed using lossy compression such as MP3?
As the cost of digital storage (e.g. Flash memory) goes down, there is a clear trend in digital music towards using less compression in order to get higher quality audio. For example, iTunes is migrating from 128Kb/s AAC to 256Kb/s AAC, and most online MP3 stores like Amazon and Walmart now offer 256Kb/s MP3. Kleer expects this trend to continue to the point where all music is uncompressed and it is critical that wireless audio technologies do not compromise this audio quality.
11. How are you extending battery life over solutions offered by the competition? How have you reduced power consumption?
The basis of Kleer’s ultra-low power consumption is our patented sub-sampling radio architecture. A conventional direct conversion or low-IF radio receiver requires an RF PLL and two signal paths (I-phase and Q-phase) each with a mixer, filter and ADC to convert the incoming signal to a baseband digital signal for further processing. This high frequency analog circuitry consumes a lot of power. Kleer is able to perform the RF to baseband down conversion and analog to digital conversion in one step using a sub-sampling ADC. This architecture has only a single signal path and eliminates the RF PLL and mixers, substantially reducing the power consumption of the receiver.
12. How have you addressed ISM band co-existence to ensure good audio quality?
Kleer transmits packetized audio and uses buffers to allow the re-transmission of corrupted packets. Kleer uses Dynamic Channel Selection to dynamically select one of 16 narrowband channels distributed across the 2.4GHz ISM band. Packets are transmitted on a given channel as long as that channel is performing well. When interference starts causing too many packet re-transmissions, the radio will rapidly switch to another channel, with the fore-knowledge that the new channel is not occupied. Even when there is severe interference, such as that caused by multiple simultaneous wireless LANs, Kleer can select a channel that fits in between the commonly used wireless LAN channels.
13. How many point-to-multipoint end-points does your solution support?
Kleer supports up to 4 simultaneous end-points. Our Listen In™ technology enables users to share the listening experience by having multiple wireless earbuds, headphones or speakers listening simultaneously to the same audio source. This is another major point of differentiation of Kleer vs. Bluetooth, as the standard Bluetooth protocol does not support point-to-multi-point transmissions.
14. How does your technology support the manufacture of small form factor earbuds?
The size of wireless earbuds tends to be driven by the size of the battery required to achieve acceptable battery life. For a given battery life objective, a lower power consumption solution can use smaller batteries. Over-the-ear Bluetooth headphones achieve less than 6 hours from a 300mAHr (or larger) battery, whereas small form factor earbuds based on Kleer’s technology achieve up to 10 hours from an 80mAHr coin cell.
15. What is the impact of your technology on the battery life of a portable media player?
Tests performed by Kleer show that a state-of-the-art player such as the iPod Nano can last up to 27 hours of continuous audio playback when using wired headphones. With embedded Kleer technology, the player would last about 20 hours of continuous use of wireless earbuds. With Bluetooth, it drops to 7 hours.
16. Why will the the PMP world go wireless?
Wires are inconvenient for the consumer. Wireless has replaced wires in virtually every applicable use case over the last 10 – 15 years; cordless phones and television remote controls are virtually 100% wireless, and there are rapidly emerging applications such as wireless keyboards/mice and wireless gaming controls. In the PMP world, earbud wires get tangled during storage, and they get caught on clothing and bounce around during use, sometimes pulling the headphones/earbuds out ofposition. The length of the wire puts limitations on the proximity of the player to the user. In the case of the popular and pricey iPod, the trademark white wire advertises the existence of the iPod to thieves. Manufacturers and users alike are looking for wireless solutions to eliminate these inconveniences.
17. Do you have a wireless earbud reference design?
Yes. Kleer has developed a reference design for earbuds that achieves up to 10 hours of audio playtime when using a small form factor 80mAHr battery. Not only is there no wire to the audio source in this design, there is no wire required to connect the left earbud to the right earbud.
18. What is the KLR3012?
The KLR3012 is the first product in the Kleer Audio/Video LP line. The module integrates our mixed signal RFIC with RF passives such that little RF design expertise is required to implement a product. It also includes embedded software that offers complete and configurable functionality enabling the implementation of products with little or no software development.
19. Have you patented your technology?
Yes. We’ve secured patents in the area of ultra-low power RF and advanced wireless co-existence technology
20. What is the size of the wireless audio market that you’re targeting?
Gartner predicts the PMP market to be in the order of 225M units in 2007, with growth approaching 300M units in 2010. Further, Gartner also predicts an increase in full feature units, including video and wireless capability. Kleer is focused on capturing the lion’s share of the personal wireless segment with a feature set optimized for portable devices. Our latest addition of video streaming for example is designed to track similar developments in the PMP space.
21. How do you plan to mass market a proprietary technology?
At a minimum, we will ensure that any product that is based on our technology will interoperate with other Kleer-based products. We have established an Interoperability Certification Program that requires OEMs to perform certain tests on their products. Compliance will result in a Kleer logo on the product packaging that tells consumers that the product will interoperate with any other Kleer-based product.
22. What is your strategy in capturing a sizable portion of that market?
Our strategy is to focus initially on consumer electronics OEMs that want to introduce wireless audio products and place a high value on audio quality. We have minimized the barrier to integrating our technology by developing a module that integrates our mixed signal RFIC with RF passives such that little RF design expertise is required to implement a product. We have also developed embedded software that offers complete and configurable functionality enabling the implementation of products with little or no software development. And we have developed reference designs to kick start our customers’ developments.
23. What applications/market segments are you targeting?
We’re targeting consumer electronics OEMs that want to develop interoperable wireless audio products for the portable, home and automotive markets. Applications include, but are not limited to, portable audio/media players, iPod® and other player accessories, home audio/theater systems, displays, earbuds, headphones, and speakers.
24. Which OEM’s have announced product using Kleer?
Our first customers hit retail in the fall of 2007. This included RCA, who launched the world’s first MP3 player with wireless headphones, and Cy-Fi, a wireless bicycle speaker. At CES2008, Sennheiser has launched the world’s first True Wireless earbuds, a product which has often been hailed as the ‘holy grail’ of the wireless audio market. This will kick off a series of product announcements throughout 2008.
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