INTRODUCTION
The introduction of the generation 3 digital radio systems broadcast architecture transforms the broadcast system from an audio based broadcast system to a general digital data broadcast system that carries audio content along with advanced application services (AAS). The transition to this architecture necessitates changing traditional audio based studio transmitter links (STLs) to generic IP based data links.
Whereas IP streams are ideal for transferring arbitrary digital information not limited to audio content, many of the challenges inherent to IP based streaming are now imposed on this architecture. The nature of this system places stringent requirements on the STL that can cause significant on air data outages.
The network and bandwidth requirements of carrying the data stream to the exciter has already been well analyzed and published1. However, to deploy a system that is successfully synchronized based on the data stream rather than external GPS based synchronization brings an additional set of challenges which are presented in this article.
An alternate transport protocol to UDP or TCP/IP is presented in this article, that drastically improves data loss across the STL by implementing an automatic repeat request (ARQ) scheme. This protocol considers the impact on studio transmitter synchronization due to re-transmissions.
The protocol operation is detailed and illustrates its capability of addressing multiple exciters with a reliable data stream. The article demonstrates a main/standby configuration, a dual station topology, aswell as, the protocol’s applicability for satellite distribution of the E2X data stream.
