The author is vice president of broadcast technology for Harris Broadcast Communications.
There has been much discussion among broadcasters and equipment manufacturers about the benefits of ATSC Mobile DTV for terrestrial broadcast TV stations — yet radio has an opportunity on these new mobile devices as well.
The ATSC M/H (Mobile/Handheld) standard offers the local TV broadcaster the opportunity to leverage a slice of its station’s bandwidth to terrestrially deliver digital mobile TV channels alongside regular DTV and HDTV services. There are also opportunities for the local broadcaster to generate new revenue streams through intuitive software widgets and more traditional business opportunities.
Radio broadcasters have an opportunity to take advantage of the ATSC M/H standard. The standard is proven to support up to 50 mobile radio services on a TV channel in lieu of mobile video service. While it is unlikely a TV station would want to carve out space for 50 radio services, there are opportunities to create a balance of mobile TV and radio services within the same bandwidth allotment.
A typical radio channel occupies between 24 and 48 kilobits per second of bandwidth. This means that a TV station with 900 kbps of available bandwidth for mobile services likely has space for audio-only services. It presents an excellent opportunity for radio and TV broadcasters in the same markets to partner for the benefit of both their stations and the consumers, who would receive both services on the same device.
The ATSC Mobile and Handheld (M/H) standard enables the delivery of IP data to mobile devices. That data could be real-time streams of video with audio, audio only or the delivery of files in non real-time. The data is arranged in ensembles or clusters of data that are coded with the same appropriate error correction.
Depending upon the amount of transmitted bandwidth required for delivering this data, a piece of main transport stream in the ATSC digital television signal is reserved to accommodate both the payload data, as well as the error correction and coding used to harden the data for mobile service.
The resulting IP stream could vary anywhere from several hundred kbps to several Mbps depending upon how much mobile payload the broadcaster wishes to transmit. The audio system employed for this service is HE-AAC version 2.0 — the high-efficiency version of the Dolby Digital Advanced Audio Codec. It is typically encoded somewhere between 24 to 48 kbps for a stereo audio channel, with the option to transmit 5.1 surround sound audio on that same channel.
The ATSC M/H standard allows for a range of audio bitrates to fit the desired quality, provided they are coded with the HE-AAC format. This allows for plenty of content flexibility in what is ultimately transmitted to consumers. A radio broadcaster could also supply still images of an album cover or a host to coincide with the current audio program (similar to Music Choice or another TV audio service or what’s soon to be possible with HD Radio). These images require very low bitrates. Images correlating to advertisements are not out of the question.
The software-defined nature of the ATSC M/H standard has been an attractive lure for local broadcasters. The standard provides room for an Electronic Service Guide to accompany mobile TV channels. Similar to a cable or satellite TV service or to the electronic program guide being developed for HD Radio, the ESG delivers program information, channel changing and other software-driven features for the benefit of the consumer. This same service can also be used for radio programming, providing consumers with in-depth information about the current service and future broadcasts.
At the 2009 NAB Show, Harris announced a partnership with Roundbox for an Electronic Service Guide system that will deliver a variety of software widgets to broadcasters that are delivered as files. Roundbox provides software to broadcasters, mobile operators and device manufacturers to deliver mobile television as well as enable new data services. The widgets essentially are pop-ups that appear in the lower portion of the viewers screen on the mobile device display. Consumers click on the widgets to receive local information that can include sports updates, news bulletins, weather and traffic information or more.
The widgets also present a revenue-generating opportunity for broadcasters in the form of advertisements or interactive services with richer graphics. At any rate, the widgets provide a Web-like, on-demand content experience that is delivered over the terrestrial broadcast model using technology that is being standardized by the ATSC as part of a future NRT (non-real-time) standard. Any content a broadcaster might post to its Web site is an ideal candidate for publishing as a widget over the mobile broadcast network.
Television stations with an existing M/H-capable system will find it easy to accommodate radio services within the same infrastructure.
A typical Harris MPH (Mobile-Pedestrian-Handheld) system for ATSC M/H Mobile DTV includes a Harris NetVX audio/video encoder and SynchronyMNA mobile network adapter to encapsulate and multiplex the IP video, audio and data services together; as well as a Roundbox ESG server that imports guide data and widget information from a station’s Web server.
The services are multiplexed with the main ATSC services and transported to the Harris Apex M2X software-defined exciter. The exciter’s signal is ultimately amplified in the transmitter for terrestrial delivery to both home and mobile consumer devices.
The entire solution adds about $120,000 to the cost of a digital television transmission system. It should be noted that the MPH system can be used with virtually any digital transmitter, Harris or otherwise, and that there are other brands of ATSC M/H-capable solutions on the market.
A simple audio encoder is added to the NetVX to enable radio services. This encoder costs approximately $12,000. The ROI for adding a radio service is easy to envision considering the initial, relatively minor, investment.
It’s clear that to make this happen, a radio broadcaster would likely need to approach a local TV station as a partner. There could be business tradeoffs. One scenario might require that a radio station broadcast promos for the host TV broadcaster. A TV station without HD network commitments may have more bandwidth at its disposal, and may have an easier time providing space for radio broadcasters in its service lineup.
Broadcasters with ownership of TV and radio stations in the same market can clearly play a leadership role. With an abundance of programming to consider, there is an excellent opportunity for these broadcasters to set an example of how TV and radio channels can co-exist on the same mobile service.
The consumer is the winner in the end, with television, radio and perhaps phone and/or high-speed Internet consolidated onto a single device. Harris has demonstrated the ability to transmit multiple services within the ATSC M/H standard at the 2008 and 2009 NAB Shows, as well as CES 2009. We believe this an ideal opportunity for broadcasters to team up and offer a robust, mobile-oriented consumer service that can potentially open new business partnerships and revenue streams for the broadcaster.
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