Computerworld Australia ci racconta come una nazione seria si sta organizzando per l'inizio delle trasmissioni di radio digitale previsto per il primo gennaio 2009. Mentre SBS (Special Broadcasting Service) punta su una codifica HE-AAC, ABC (Australiana Broadcasting Corporation) parla ancora di MPEG 1 layer II, ma a parte questa apparente contraddizione (dovranno convivere trasmissioni DAB e DAB+? Non si capisce bene) spicca l'uso di una infrastruttura comune e di un sistema di distribuzione satellitare-terrestre basato su protocollo IP. Obiettivo: offrire una copertura perlomeno equivalente all'attuale infrastruttura AM/FM, se non superiore, nelle aree metropolitane nelle quali è pianificato lo startup.
ABC, SBS prep new digital radio service
IP the preferred distribution technology
Rodney Gedda (Computerworld) 03 September, 2007 12:32:36
The Australian Broadcasting Corporation (ABC) and the Special Broadcasting Service (SBS) corporation have started sourcing equipment and support for its new digital radio services for all state capital cities due to begin broadcasting in January 2009. Both organizations have jointly called for proposals for providing equipment, distribution, and transmission services for the new digital radio broadcasts. The technical requirements are divided into data servers, encoding, multiplexing, and time zone delay systems; distribution; transmission; and monitoring and logging.
The new services follow a federal government policy announcement for the introduction of digital radio services. A request by the Department of Communications, Information Technology and the Arts (DCITA) was made to national broadcasters to identify costs for a shared digital radio infrastructure. The first stage involves the implementation of six metro city transmission services, which has already been approved by the government. Regional expansion for national coverage of the new service is planned but is yet to be endorsed by the government. The ABC and SBS have agreed to share digital radio infrastructure which will minimize distribution costs, and common services and infrastructure are required where possible for the carriage of the combined ABC and SBS digital streams on land and via satellite.
The digital radio services will be encoded in digital audio broadcast (DAB) format like MPEG4 and HE-AAC v2, and, according to tender documents, the system must be designed so that no single equipment failure can put the whole service off-air. "Internet protocol (IP) connection is preferred for data input and output on the data servers [and] the system shall support and facilitate acquisition of program associated data such as slide show, photos, and text and its subsequent play out along with the audio program," according to the joint proposal. SBS has nine studios in Sydney and in Melbourne and uses Netia servers for broadcasting via Klotz digital mixers. "It is essential that the encoding system integrates with the existing program playout system in SBS given that at least two radio channels will be simulcast in AM and FM using this equipment," according to the proposal.
The ABC expects to produce 20 digital programs in Sydney to broadcast nationally, and up to 10 programs will be generated in each state, encoded in MPEG-1 layer II format. For distribution, both the SBS and ABC are looking for a fully managed solution with an availability of at least 99.985 percent, preferably via IP. The IP networking equipment to distribute the digital radio content will need to be procured as part of the project. Logging recorders are also required by both broadcasters in each capital city and there is a requirement to access the program loggers in any of the six capital cities remotely via IP to replay the audio and view the broadcast of any channel.
The broadcasters use Optus satellite services and the network requires geographically diverse and redundant paths to the satellite uplink. The Australian Communications and Media Authority is responsible for frequency allocations for broadcasting services and although planning for the transmission services is yet to be completed, both broadcasters expect the new transmission services to provide coverage equal to or greater than the existing FM radio services in each capital city.
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