At yesterday’s HD Communications Summit, most equipment manufacturers said they would like to see fewer HD codecs and an “HD voice” logo to slap on to their boxes and gear. Discussion also took place on the relative virtues of a “free” codec and the intellectual property issues associated with free codecs.
Handset manufacturers Polycom and Snom expressed a belief that more is less with fewer codecs. Existing HD codecs are “good enough,” said Polycom’s Chalan Aras, but there needs to be “convergence” with fewer selections “Fax has one standard and look where it’s gone,” Aras stated.
Despite advances in more memory and faster processing speed, every codec added to the stack of must-support features adds cost, even if it is “free.” Each codec consumes memory and therefore requires more resources and more resources bump up the expense of the parts put into a desktop handset.
More codecs also increase the complexity of support in having to transcode between one codec to another one and having to transcode between different codecs can introduces various artifacts and degrade voice quality, noted Polycom CTO Jeff Rodman — not something you want to do with HD voice. In an ideal world, the same codec would be used from end-to-end, negating the overhead and potential issues with transcoding. Rodman would like to see the industry downselect to two or three HD codecs.
Finally, so-called “free” codecs still require verification testing and support, not to mention the cloud of potential intellectual property liabilities for developers; GIPS made sure to underscore the latter point. Ryan Heidari, Director Technical and Product Marketing for Qualcomm, said carriers tend to shy away from proprietary but free offerings; they want to open source, fully published C code to verify what is under the hood and to enable the codec to be adopted by multiple manufacturers.
Summit sponsor AudioCodes was more prosaic about transcoding, believing that as long different industries picked different HD codecs, there would always be a need for an appliance in the middle of the communications stream to conduct transcoding between different carrier “islands.”
One of the challenges the HD Voice world faces is the divergent needs of wireless and wireline carriers. Qualcomm’s Heidari stated wireless carriers want spectral efficiency due to their relative limitations in bandwidth relative to other service providers.
Snom founder and CEO Christian Stredicke found plenty of support in a call for a standard “HD Voice” logo that could be put on the side of a box. Another speaker noted that a standardized “HD voice” certification or logo would provide a differentator in the marketplace.