FAQ

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Q1.
 What is digital audio broadcasting (DAB)?
A1:
 Digital audio broadcasting (DAB) is a robust form of broadcasting using digital compression technology to deliver audio, text, pictures and data in a binary bit stream. As DAB system serves an area by using one single frequency network (SFN), more radio services are available alongside with data and pictures transmissions. This significantly expands the number of channels and allows for a more efficient use of the available spectrum as well as more interactions with audience.

Q2.
 When did RTHK begin the DAB trial? When will it end?
A2:
 RTHK launched its first DAB trial in 1998 to test the reception of DAB L Band. Earlier this year, RTHK conducted another test on the DRM Medium Wave technology, which aimed at improving AM reception. Another trial on DAB Band III took place in September this year and will continue until early 2005.

Q3.
 Why should Hong Kong test the DAB technology?
A3:
 Comparing with the existing analogue broadcasting system, DAB has the following advantages:
(1) Using single frequency network that enhances mobile reception and no fine-tune of frequency is required;
(2) Rooted out the problem of ¡§multi-channel interference¡¨ in FM broadcast;
(3) Provides crystal clear sound that is comparable to near CD quality or even to the surround sound effect;
(4) Data transmission alongside with audio broadcast providing text-based information such as instant report on finance, weather and traffic news etc;
(5) More channels are available in the same frequency spectrum when compared with FM transmissions. Each 1.5MHz frequency spectrum of DAB can transmit six sets of CD quality programmes.

Q4.
 What are the technical details of the current DAB Band III trial?
A4:
 The trial adopts Europe's Eureka 147 system, with the frequency 218.64 MHz. The maximum transmission power is 400W. This system is widely adopted in Europe.

Q5.
 Is the whole Hong Kong being covered in the current DAB trial?
A5:
 No. The trial covers 40% of the population in Hong Kong. Two transmitters have been set up at Mount Gough in Hong Kong and Beacon Hill in Kowloon, covering areas in Hong Kong, Kowloon Peninsula and Shatin.

Q6.
 How can I receive the DAB trial signals?
A6:
 Digital audio broadcasting requires a purpose-built receiver incompatible with the existing analogue model.

We are planning to set up trial points at different locations in Hong Kong Island, Kowloon Peninsula and Shatin in early 2005 to let public experience the high sound quality of this new technology.

Q7.
 Where can one buy a digital radio receiver?
A7:
 Since DAB has not been introduced to Hong Kong, shops do not sell digital radio receivers. However, they are available at shops in Europe, Americas and Asia.

Q8.
 Why my DAB receiver sometimes fails to receive any DAB signal?
A8:
 There are several possible reasons:
(1) The receiver is outside the service area of DAB trial.
(2) The receiver is placed far away from window.
(3) The antenna has not been fully extended or properly adjusted.
(4) There may be problems with the computer programming for some of the DAB receivers. Cutting off and reconnecting the power may solve this problem.

Q9.
 Is DAB widely adopted in other countries?
A9:
 DAB has been developed for some time. Currently, as many as 300 million people in 25 countries are served by DAB. In Asia, DAB is being tested or available in Mainland China, Australia, Singapore, South Korea and Taiwan.

Q10.
 What about the adoption of DRM, which was tested in Hong Kong earlier this year, around the world?
A10:
 Currently, over 50 regional, national and international public and private broadcasters are providing DRM service, including BBC and radio stations in Russia, Berlin, Germany and New Zealand. Most of these stations are adopting DRM for short wave services.

Q11.
 RTHK has tested different DAB technologies. Which is the most suitable one for Hong Kong?
A11:
 RTHK has tested DAB L Band and Medium Wave DRM. Although DRM can significantly improve AM sound quality, it can only be used with short wave and medium wave channels.

DAB, however, provides better sound quality, data transmission and serves with single frequency network. RTHK tested DAB in L band in 1998. Since then, DAB technologies have undergone improvements; RTHK¡¦s current test of DAB VHF Band III is expected to offer a better indoor and outdoor performance. Moreover, the price of the receivers has gone down substantially.

RTHK will study data collected in the tests and make a proposal to the government in due course.

Q12.
 When will Hong Kong launch its DAB service?
A12:
 RTHK has been keen at providing DAB service. Since 1998, we have conducted three trials on the technology and held seminar on the topic.

RTHK will look into the issue with an aim of providing better service to the public. We will make arrangements as soon as the government announces the issue of a DAB licence.