Multiplexing audio programs for IP transport over satellite


RCF, a French private radio station that broadcasts nationwide, needs to replace and upgrade its multiplex generation solution for several reasons. Built on obsolete devices, the current solution is cumbersome in a limited bay space, and is also reaching its technical limits in terms of program density multiplexing. Ultimately, broadcast should be uninterrupted as continuity of programs is critical in the radio industry.


RCF crew has a full list of requirements when it comes to selecting a new solution. The new system should:

  • Generate a MPEG-TS MPTS stream from 23 regional IP streams
  • Gradually integrate additional regional programs, scaling up to a capacity of 64 programs
  • Replace on-the-fly contents of any program in the multiplex by any input program, without audio discontinuity
  • Switchover to a backup input source in the event of loss or silence detected on each input regional flow
  • Migrate from MPEG Layer 2 audio format to AAC format
  • Be able to upgrade to stereo programs (programs are currently in mono).
  • Provide easy management of alarms and configuration
  • Provide 1 + 1 hot redundancy to ensure program continuity
  • Integrate the renewal of codecs in regional studios, with support for analog audio sources, AES / EBU, and Livewire (AoIP)
  • Be as compact as possible to save space in technical bays


Digigram has built a solution based on redundant IQOYA X/LINK-LE encoders and an IQOYA SERV/LINK transcoders.Two network ports with the possibility of declaring multiple VLANs allow physical and logical separation of the various IP traffics (input flow, output flow, control and supervision), and a level of network quality of service (QoS) can be affected for each stream sent. Finally, different FEC schemes, as well as the redundant streaming mode on two networks, are proposed in encoding and decoding of flows to compensate for the possible loss of packets during transport over IP. Digigram suggests a solution based on the use of the IQOYA SERV/LINK multichannel audio gateway on IP in its version dedicated to transcoding streams, associated with the IQOYA LINK / LE gateway in regional studios.