Yes, that is exactly what it sounds like…formal specifications for delivering wideband voice over traditional FXO/FXS connections.
This is more than just a curiosity, and could be very valuable to the widespread adoption of HDVoice outside of the mobile space.
Let’s consider the case of the Cable Companies. It’s been noted that their “Digital Voice” customers are well positioned to benefit from HDVoice. Cable companies have gained many residential and SMB voice lines in recent years, enough to cast Comcast as the third largest Telco in the US.
A short while back I addressed the question of how DECT & CAT-iq may foster the broad deployment of HDVoice. At that time I described one possible scenario where carriers would deploy customer premises equipment (CPE) with an on-board cordless base station. Although a frontrunner, and the basis of Comcast’s (decidedly non-HD) HomePoint service, this is not the only approach afoot. There’s another possibility arising that involves conveying HDVoice over a plain old analog RJ-11 connection.
At first glance HDVoice and analog lines would certainly seem to be mutually exclusive. The common wisdom is that wideband telephony requires the use of an all-IP call path. This is in fact a generalization, and not absolutely true.
Firstly, it has long been possible to pass wideband audio, in the form of G.722 encoded media, over the PSTN by way of ISDN connections. Also known as BRI interfaces, an ISDN connection supports up to two 64 kbps channels (bearer channels) and one D channel for the purposes of call setup & teardown signaling. High-quality voice using G.722 was one of the selling points of ISDN in the 1980s.
Earlier today Doug Mohney of HDVoice News posted a short item from The Cable Show 2011. He was speaking to Derek Elder, Senior Vice President of Arris, a manufacturer of cable network infrastructure. The company claims that it has 15 million Arris end-points deployed, all of which are potentially capable of HDVoice.
To be more specific, these various end-points would be G.722 capable given a firmware upgrade. But there is a catch…the user-end interface is a standard analog RJ-11. That means that a digital voice subscriber would require correspondingly capable analog phone.
The legacy PSTN standards define how analog phones are built. The frequency response of devices is deliberately constrained in order to protect the network. Thus a wideband capable analog phone is at present a very rare bird.
Nonetheless, the company is able to demonstrate wideband voice using this approach in their Atlanta lab. That means that the firmware truly exists, as does the requisite hardware. So it would appear that there may be an alternative to the integration of SIP/CATiq that has been dominating the cable landscape with respect to HDVoice.
Doug Mohney’s HD Voice News has a good overview of David’s petition. David’s idea was that the merger hearings present an opportunity to point out how the ILECs have utterly failed to advance the issue of call quality. What Doug doesn’t mention is the mechanism of David’s presentation on May 27th.
The company describes the “HD Audio” feature as follows:
“The frequency band has been extended allowing for the signal to be reproduced and tuned for a fuller and clearer sound.”
In addition, they seem to have implemented a kind of tone control with several preset contours.
“The equalizer feature on the handset enables you to change the audio quality of the handset to best suit your hearing. While on a call or intercom call, or listening to a message or announcement, press EQ to select the equalizer setting Treble 1, Treble 2, Bass or Natural (the default setting) for the handset. The current setting is displayed on the handset briefly.”
Since these are DECT 6.0 devices it’s possible that the cordless aspects of the system use G.722 encoded audio to provide higher quality sound for calls between handsets. However, since the device offers only the analog PSTN interface to the world it’s going to be limited to narrowband G.711 for all calls to the PSTN. The intercom function may be improved, but it’ll have limited impact upon most of the things that people do with a telephone.