One of the missing pieces out of the HD Communications puzzle is standards — yes, plural. There are plenty of codec standards, mind you, but what defines an HD phone call, really? The telecommunications industry may have to borrow from a page from the TV world at some point down the road.
The lowest common denominator (LCD) for wideband codecs seems to be the almost archaic G.722 — but longevity and a little tweaking over the past couple of years isn’t a bad thing, mind you. Manufacturers have embraced and incorporated the codec into their hardware and it has become a part of the DECT CAT-iq cordless home phone effort — and DECT CAT-iq is the HD/cordless standard for the cable industry.
Companies onboard with G.722 in handsets include VTECH, Siemens Gigaset, ooma in the consumer world and Avaya, Cisco, Polycom, and snom in the business arena.
Going into the wireless world, the standard with the most traction is AMR-WB, also known as G.722.2. Spectral efficiency is the name of the game, so there’s a different manipulation of the media stream to conserve bandwidth and this segways into transcoding.
Can you do better than the two existing LCDs? A number of parties believe they can for various reasons, including bandwidth efficiency, CPU optimization/trade-offs, and the like. Skype’s SILK codec is probably the best/most publicized effort for Yet-A-Better (YAB) wideband codec for speech applications.
What if you want to go beyond the LCD and get the very best experience, period? There’s no definition yet for that in the HD phone call world which puts us slipping towards the Digital TV world to borrow some concepts. Under this to-be-defined-framework (Hello? HD Connect? Hello?), a PSTN call would be “standard definition” and the baseline service when HD wasn’t available. The next step up would be in the G.722 and AMR-WB frameworks — the equal of the 720p in the wireless and wireline worlds.
Finally, at the top of the heap would be a 1080i/1080p standard, for the very very very best in sound quality. Is this something akin to CD quality? Or do you go higher and provoke a fight with audiophiles and embrace DVD Audio or something equally challenging?
Be interesting to see what Jeff Pulver thinks about this framework.