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Apr 1, 2002 12:00 PM, By Joseph F. D’Angelo

As the conversion to IBOC nears, the benefits of enhanced audio quality for both AM and FM broadcasts are widely known. However, the ability for broadcasters to transmit a wide variety of data services along with their current audio programming promises to unlock entirely new opportunities for broadcasters.

IBOC system capabilities

Ibiquity’s IBOC system has been designed to support the broadcast of data services in all modes of operation: FM hybrid and all-digital, and AM hybrid and all-digital. In the hybrid mode, broadcasters will continue to transmit an analog signal while adding the IBOC signal in the sidebands. Each mode will have different data throughput rates, but in each case a significant amount of data can be delivered representing a substantial upgrade to the existing subcarrier services.

IBOC�s data capability will be able to provide enhanced radio services.

Due to the nature of the FM band, FM broadcasters will have the greatest potential to leverage datacasting opportunities. The FM hybrid mode can deliver up to 150kb/s of throughput. Our current design has the maximum audio rate set at 96kb/s, which would result in 54kb/s being available for data services. This rate, while only a one-way transmission, far exceeds the throughput of other widely available wireless transmission systems at a fraction of the cost. In the all-digital mode, the capacity of the broadcast throughput roughly doubles to approximately 300kb/s, ample capacity to support five-channel surround sound and sophisticated data file transfers.

The AM band is significantly bandwidth limited in comparison, but it will be able to deliver meaningful data services. In the hybrid mode, the AM system will deliver 36kb/s throughput, delivering an FM-like stereo audio signal while supporting text-based message delivery. In the all-digital mode, the capacity of the AM system will increase to 60kb/s with the maximum audio rate set at 56kb/s.

Both AM and FM will be able to selectively utilize channels and carriers while at the same time dynamically controlling the audio data-compression rate. Trade-offs between audio and data throughput can be made in real-time as required or preset to support scheduled daypart requirements, ensuring high audio quality while maximizing the datacasting capabilities.

Radio data applications

Broadcasters will be able to provide basic programming information like station identifiers, artist and CD labels and song titles comparable to what satellite radio is currently delivering. This capability will provide the foundation for other message-based services that will enable broadcasters to generate revenue from their datastream with enhanced advertising and information services.

As IBOC receivers advance and manufacturers take advantage of enhanced displays, storage capacity and in-vehicle applications, the utility of an IBOC data broadcast significantly increases. Broadcasters will be able to brand programming for display on rear-seat entertainment units, stream 800 numbers and URLs of advertisers for easy retrieval from a receiver, deliver valuable information inexpensively to a telematics provider’s customers and update integrated navigation systems with real-time traffic conditions and location-based advertising. Couple these receivers with a return channel and listeners would be able to complete transactions for concert tickets, CDs or additional advertising information.

While these scenarios may seem futuristic, many companies have already made significant steps towards enabling these services and applications, increasing the value of a broadcaster’s data capacity and evolving into a significant revenue stream for stations.

Open applications development platform

To ensure that broadcasters and receiver manufacturers are coordinated in the effort to make IBOC datacasting a reality, Ibiquity launched a formal process in October 2001 to develop an Open Applications Development Platform for IBOC. The goal of the IBOC Wireless Data Working Group is to rapidly develop and disseminate a protocol suite that facilitates application development and ensures interoperability between broadcast and receiver technology. Representatives from all major IBOC constituencies are participating in this process including station owners, receiver and broadcast equipment manufacturers, application developers and automakers. The development process is structured in three phases:

  1. Use case development. Identify core applications and functions;
  2. Device Profile Definition. Support the core applications and functions; and
  3. Data Structures and Rules. Interface to functions and applications.

The first two phases have been completed and the results will be presented on April 6, 2002. Phase 3 is scheduled to be completed in the summer of 2002. This will represent the baseline IBOC application development environment that will be enhanced over time to support new and emerging datacasting applications.

D’Angelo is director, PAC and wireless data business development, for Ibiquity Digital.