DECODING MEDIA CONTENT

摘要

A wireless receiver (17), in the form of a mobile telephone, comprises a DAB receiver (31) and a GSM/GPRS transceiver (29) which enables bi-directional point-to-point data communications via a service provider (55). The DAB receiver (31) is arranged to receive media data from an over-the-air broadcast channel, the media data primarily representing television and radio streams. In order that the streams can be decoded and decrypted by media playing software (47) on the wireless receiver (17), a provisioning operation is employed to provide NSC header files and DRM licences to users in response to them making content requests. The header files and licenses are sent over a separate data channel and in advance of the broadcast content. The filenames of NSC header files may include information indicative of a time period over which the header files are valid. In response to selection of a particular service, software at the wireless receiver (17) is arranged to identify whether a corresponding NSC file is valid based on the time period encoded within the filename, and where two or more corresponding NSC files are present, to perform memory management to delete redundant NSC files.