As the rollout and deployment of next-generation services like VoLTE, VoWiFi, and WebRTC accelerates, interoperability between different generations of devices and networks becomes more and more important. When considering how to make legacy and new-generation services play nice with each other, it’s important not to forget the transcoding architecture, which is the topic explored in a new Radisys eBook Evolution of Transcoding Architecture In the Network.
Due to advances in technology, available processing power, and varied networking requirements, the number of unique voice and video codecs continues to proliferate. There’s a codec optimized for just about every scenario: high image resolution, broad spectrum fidelity, lower data bandwidth, simple processing, or accommodation of information loss over wireless networks. And there are still more codec requirements to come, with the increase in IMS-enabled services with SIP endpoints, WebRTC and OTT applications, and a need for high-definition video codecs.
So the process of transcoding is a key enabler of service interoperability. Until all users are on the same kinds of devices and the same standard network, there will be a requirement for transcoding to support useable services. You’ll need a good transcoding architecture if you want to monetize and protect your investment in your service infrastructure.
Transcoding, and especially transcoding with the newer codecs, is extremely processor-intensive. In the past, the transcoding function in the network was tightly tied to signaling and packet processing. Going forward, with the predicted rise of use cases involving processor-hungry services such as VoLTE and VoWiFi, the transcoding architecture needs to evolve.
Adjunct media transcoding deploys media transcoding as an adjunct to signaling, RTP, and security. When a border element such as a Session Border Controller (SBC) or Media Gateway (MGW) detects a media stream requiring complex transcoding, it redirects the stream to an adjunct media processor. The adjunct media processor acts as a distributed Media Resource Function (MRF), with control defined by IMS standards.
The adjunct approach allows a broader range of services, extending the role of the MRF to support next-generation multimedia transcoding with existing, legacy SBC and MGW elements. The result is an approach that delivers a significant ROI due to the ability to leverage existing infrastructure, and optimizes independent scaling of media processing and signaling.
