So Where’s It Going?
The first DSP-based voice-processing board supported a single port of voice. And, in an indication of things to come, it also provided a V.22bis (2400 bps) data modem on the same chip. In 1988 we had the first DSP-based multi-line voice boards, providing improved performance (especially in call-progress analysis) and flexibility over earlier multi-line voice-processing boards. Of course, the DSP vendors didn’t stand still. Just as in any other sector of the semiconductor industry, developers of DSPs have provided stunning improvements in price-performance. Falling prices and increasing performance have, in the mid-’90s, giving rise to the “high-density” multi-line board. Today, high-density boards simultaneously process four or more PCM streams per DSP, yielding densities of up to 60 ports of voice and fax on one board.
Further improvements in DSP price/performance will usher in the high-density “integrated-media” board which will dominate the last third of the decade. In 1998 the industry will see 60 voice streams, 48 faxes, and 10-15 high-speed data modems–all one DS. Integrated-media boards can offer higher densities, reliability, and performance, while offering lower cost and development time. However, a few problems have to be solved before this happens on a wide scale.
One problem has to do with board-level resource management. There is a wide range of DSP and RAM resources required, for example, to implement typical voice-processing functions and those needed to implement a V.34 data modem or speech recognition. It’s possible to optimize a board for voice and eliminate any capability to process other, more resource-demanding, media. So if one DSP can handle 60 voice streams and 15 high-speed data streams the board must include flexible resource management of MIPS, RAM, and media streams.
Another problem has to do with industry efficiency. Since no “voice board” vendor has the resources or competencies to internally develop all media-processing technologies, we have the possibility of all of them developing their own proprietary closed-architecture boards, and then going to the various media-processing technology vendors to port their code to the board vendor’s platform. So the technology vendors will have their developers work on porting (technology shuffling) rather than developing newer and better technology. That’s not as efficient as our industry should be. It’s certainly a lot less efficient than the PC industry.
An elegant solution for the computer telephony industry would be to define a board-level environment that would allow the technology vendors (yes, including voice technology) to do it just once. They would then offer their technology as a board-level “application” which would run on any board which provided the industry-standard environment. Just as host-level application developers access system resources through APIs, the technology vendors would do the same, only at the board level. These APIs would be for the media stream, the external system interface (host), DSPs, and so on. And just as good host-level APIs hide the operating system (for portability) from the application developer, good board-level APIs would hide the board’s operating system from the developer.
Maybe we will see shrink-wrapped media-processing technology in the not-too-distant future.