Apart from TV programme services, DTT also supports interactive and datacasting services that may or may not be related to the TV programme service being aired. Such services are either one-way or two-way.

Enhanced (one-way) Services

One-way services provide additional information or viewing options offered by the broadcaster without actual communication with the broadcaster via a "return path". With just a press of button, additional information already embedded in the programme being transmitted will pop up on the screen, such as subtitling for a programme, recipe or ingredients of cuisine in a cooking programme, information about leading characters in a drama, multi-angle presentation of a football match, multi-ending options for a drama series, etc. Information unrelated to TV programmes may also be transmitted, such as financial data, weather updates and traffic news, etc.

Electronic programme guide (EPG) is another example of one-way service. It is an information service which can include visual images relating to the promotion, listing or selection of TV programmes or services. It allows a broadcaster to provide information about its programmes or additional services and to market and package them in a manner which is convenient and attractive to viewers.

There are a number of levels an EPG service may take, ranging from a simple TV listing guide to a sophisticated electronic magazine allowing programme previews and featuring linkages with conditional access and subscriber management systems.

Interactive (two-way) Services

Unlike the one-way services, two-way services enable viewers to send their response back to the broadcaster via various means, such as telephone lines or mobile networks. With such capabilities, viewers can participate in electronic games, home shopping, home banking, TV competitions, commercial transactions, etc.

The Government has not imposed any requirements on such enhanced services because we believe that the commercial broadcasters should be given the flexibility of devising their business models on the digital platform.