Conventional FM radio broadcasts used analog signals to reach receivers. The FCC had approved a new system which allowed radio stations to broadcast using digital signals that seamlessly integrated with the existing broadcasting spectrum and infrastructure. This became known as “HD” (High Definition) Radio because of its near-CD quality audio that was broadcast in 5.1 channels. Other benefits included the ability to transmit subcarrier data, reduced fading and multipath effects, enhanced immunity to weather, noise, and other interference, and expansion of the listener base by increasing the number of stations that could broadcast within a given frequency band. Digital radio broadcasts in the US and Europe were currently offered without subscription charges, which was likely to open the market to a greater audience than that of XM and Sirius. In fact, some views were that HD Radio would replace the market created by satellite radio, bringing high quality radio broadcasts to an architecture based an local transmitting towers.
In order to transition to HD Radio, broadcasters simply added new digital transmission equipment, while consumers transitioned to digital through the use of newly-introduced HD Radio receivers. Since 1995, the United Kingdom and other European countries have operated digitally broadcasting radio stations, which led to the development of a wide range of digital radio receivers for both vehicle and home/office use. These included a digital display, capable of presenting the user with up-to-the-minute news, sports, and weather headlines or bulletins in a scrolled text format. Currently 723 stations in the US were digitally broadcasting, including 12 in Iowa , 35 in Minnesota , 18 in Washington , and 31 in Michigan .
The Vision:
Digital radio offered similar data transfers to that of Satellite Radio, with the added benefit of localization and free service to end users. Large amounts of custom traffic information could be sent to vehicles from the nearby station, without being broadcast nationwide. This data could come directly from the state’s automated Condition Reporting System.
In its early stages, in-vehicle digital radio receivers presented information on the radio display (similar to how some radios now display the title and artist’s name of the current song). In the future, it was possible that data could be extracted from digital radio broadcasts by in-car navigation systems to provide a more interactive experience, including up-to-date maps of traffic information ranging from incidents to tourist events.
Project Summary
Research was carried out into digital radio and its potential applications towards traveler information dissemination. This included researching and understanding the bandwidth available, amount of data lost, distance of broadcast, potential for interference, and cost of commercial digital broadcasting equipment. Secondly, the study examined the extent of consumer radios currently available with the capability of receiving digital signals, established their prices and any compatibility problems. The displays were researched to find standards for the number of available pixels, characters, and lines. This allowed for the final part of the study – research into a potential partnering radio station in an ENTERPRISE member state that may have agreed to be part of a trial deployment as a later project.
Project Activities
The work to be completed as part of this project is as follows:
Task 1: Understanding Digital Radio
Efforts in Task 1 researched digital radio to establish its suitability for disseminating traveler information. This included examining the digital system and all of its required components. Efforts in Task 1 also researched the market for HD radio receivers to understand the anticipated penetration of such receivers in American vehicles over coming years, and to understand the capability for traffic reports to be displayed on standard HD radio receivers.
Task 2: Identifying a Partner for a Trial Deployment
Efforts in Task 2 took the findings of Task 1 and worked in an ENTERPRISE member state to educate and build a relationship with a radio station that may have agreed to serve as a partnering agency in a later field trial. Candidate radio stations were either current HD radio broadcast stations, or stations that may convert to HD broadcasts. Public owned radio stations (ie. KBEM in Minnesota) were candidate stations, as well as more traditional private stations. Efforts in this task supported outreach, education and partnership building with candidate radio stations, and also gave ENTERPRISE members insight into the willingness of radio stations to work with State DOTs to eventually broadcast travel information
Task 3: Final Report
Using the findings from Tasks 1 and 2, a report was created outlining potential applications for digital radio for traveler information dissemination. This included its advantages and disadvantages when compared to existing systems, and the feasibility for traveler information, considering both technical issues as well as the radio stations’ willingness to collaborate with State DOTs. The Final Report also outlined a potential Phase 2 project to serve as a field trial of HD radio in one or more ENTERPRISE member states.