DIGITAL HARMONY NON-1394 TECHNOLOGIES

Digital Harmony's intellectual property portfolio contains four complementary non-1394 technologies that are valuable to manufacturers and home network installers: BiDAT, WireFree, PAWS, and REALM.

BiDAT Transceivers

Digital Harmony's BiDAT (U.S. and foreign patents pending) transceivers allow data and audio to share existing speaker wires or line-level interconnect cables. This allows simple devices (such as a speaker) to communicate with an intelligent device (such as a decoder/amplifier) without incurring the expense of a sophisticated communications interface. BiDAT is a very inexpensive alternative to IEEE 1394, giving speakers the same bidirectional communications capabilities as any other Digital Harmony audio device. For example, a BiDAT speaker with an IR window could be placed in a bedroom, allowing the consumer to use an IR remote control to manipulate a stereo system in the living room.

The essential features of Digital Harmony's BiDAT transceivers are:

• Transparent—data signal does not interfere with audio signal

• Full duplex—bidirectional signal up to 56 Kbps

• Low cost—transceiver component costs are less than $5 (U.S.)

• Small—modest space requirements

• Line-powered—option eliminates power supply in existing installations

• Compatible—supported by Digital Harmony Protocol Suite

A block diagram of a typical Digital Harmony BiDAT amplifier is shown in Figure 12.4.

WireFree Transmitters and Receivers

Digital Harmony's wireless audio transmitters, developed in partnership with Music Sciences Inc., use a revolutionary digital transmission technology—WireFree (U.S. and foreign patents pending). The WireFree digital wireless system brings eight independent CD-quality digital audio signals to home theaters. WireFree is a feature-rich alternative to hard-wired IEEE1394-powered speakers, providing transmission links of up to 20 meters—standard IEEE 1394 copper cables can only be used at lengths up to 4.5 meters. WireFree technology is compatible with the Digital Harmony protocol suite.

PAWS Watermarking Codecs

The PAWS audio watermarking system (including U.S. Patents 5,473,631 and 5,404,377; foreign patents pending) is a watermarking method based on perceptual coding, allowing data (PAWprints) to be hidden in an audio signal. This technology is used by software companies to mark a recording with a unique code, allowing each copy to be tracked after it is sold.

The essential features of Digital Harmony's PAWS system are:

• Discreet—does not perceptibly interfere with audio signal

• Robust—data integrity and extractability survives "low-fi" conditions

• Secure—PAWprints can not be removed or altered

• Accepted—approved for use by multiple television broadcast networks

• Proven—currently in use by a major media research company

• Compatible—supported by Digital Harmony protocol suite

REALM Codecs

REALM (U.S. Patent 5,612,943; foreign patents pending) Codecs allow the recording of data along with audio, using standard Red Book audio recording methods. The encoded data can be retrieved from the analog outputs of any audio player such as a portable CD player. The essential features of Digital Harmony's REALM Codecs are:

• Easy—REALM encoding tools used to create content

• Simple—data easily retrieved from analog outputs of any audio player

• Low-Cost—low decoder component cost, less than $5 (U.S.)

• Consumer-Friendly—works with any portable CD player

• Transparent—data signal does not interfere with audio signal

• Synchronous—allows data delivery to be synchronized with audio

• Compatible—supported by Digital Harmony protocol suite