» HD Voice. The Future of VoIP?

HD Voice. The Future of VoIP?

Since HD Voice was introduced to the VoIP community a little over two years ago, it has been feverishly debated. How will it affect the future VoIP? How much better is it really? Is it worth switching to now? This post helps clarify many of the questions people have and provides a brief over of some the specifics of HD Voice.

What’s the Big Deal?

Everything is better in Hi Def. Right? Well, HD Voice does in fact provide a better experience for the listener. Without getting into too much detail, HD Voice can transmit over twice the range of audio frequencies that traditional lines can. So, if traditional lines transmit from about 300 Hz to 3,400 Hz, HD transmits from about 50 Hz to 7,000 Hz. This means that sounds at much lower frequencies and sounds at much higher frequencies can be heard clearly. Are you beginning to see the benefits? Imagine a world where talking on the phone is like talking to someone in the same room as you. Where having to call back someone for clarification or interrupting a speaker in the middle of a conference call because you couldn’t understand something is no longer common place. Wouldn’t that be wonderful?

What’s the Catch?

Of course, if HD Voice were so great it would have already taken the VoIP world by storm, but like all new technologies there are bugs to work out. First of all, if a call made using HD voice has to travel over traditional land lines or a regular VoIP service the HD call quality will be lost and the listener will not experience HD voice. Additionally, since HD voice transmits more frequencies it takes up more bandwidth. Therefore, offices that have multiple people making phone calls will probably have to increase their bandwidth to avoid problems with queuing, buffering and other complications with WAN or LAN equipment. Also, users may have to invest in HD phones to get their full money’s worth. While HD compatible phones do exist, some argue that they don’t deliver full HD voice quality. Another problem with HD phones has to do with what type of codec is integrated with the particular phone system. Codec stands for coder/decoder, and VoIP systems use them to transmit audio data. Currently, there are a number of different wideband codecs that support HD. They all have different bit rates, sampling rates, and system requirements. The ITU-standard wideband codec is G.722 and this is in fact the most widely used one. Even so, the multiple variations create problems with compatibility when audio data is being transmitted between systems that don’t support similar codecs. As HD voice becomes more prevalent the industry will push toward using a single codec, but until then compatibility problems will still be a major issue. Finally, how much do you really want to hear of what’s going on over the phone? Better yet, how much do you really want the person you‘re on the phone with to hear? All of a sudden that private conversation a cubicle over isn’t so private anymore and every pencil tap is heard loud and clear.

What’s Next?

Online posts from notable VoIP opinion leaders, like Jeff Pulver, claim that HD Voice for VoIP is the wave of the future. It’s true that the technology is there, but for it to truly take hold quickly there will have to be a unified movement toward HD voice. Users will have to be willing to upgrade equipment and infrastructure. Even then HD to HD calls will be worthless if they have to travel over a traditional land line. This doesn’t mean that you should totally write off switching to HD. It’s sensible to make upgrades if the time is right and HD calls made between office branches can be useful for productivity. Overall, HD voice is not something that you should worry about upgrading to right now. However, in order to avoid being behind the curve, it’s sensible to make plans to switch in the next few years as HD calls become more common place.

Uncategorized | fbnewman | June 17, 2009 2:25 pm

4 Comments

By John Lincoln, July 1, 2009 @ 4:41 pm

HD voice with have to be adopted eventually. It is human nature to continually want to improve technology, we will never reach a point where we say “this is good enough.” Also, the companies that invest and offer HD voice will have an inherent added bonus within their product offering. Our product does not offer HD voice at this point, however, we do see the value in it. We have always made it a priority to invest heavily in voice quality, and we feel that ours is an industry leader at this point. I invite you to check out our new VoIP blog http://www.freedomiq.com/blog.
By Michael Graves, July 21, 2009 @ 10:38 pm

I can hardly believe the amount of over-simplification you’ve managed to squeeze into a blog post. It’s so scrammed in there that it squished the paragraph structure out entirely.

On to the bad information…

“HD transmits from about 50 Hz to 7,000 Hz”

That’s the absolute minimum, worst case that anyone would consider a HDVoice call. Tyical of G.722. Some codecs support audio bandwidth > 20 KHz. Yes, music quality.

“Additionally, since HD voice transmits more frequencies it takes up more bandwidth.”

That’s patently false, or at best misleading. Of the many wideband codecs out there only a few use any more bandwidth than plain old G.711 that we call PSTN “toll quality.” G.722, the oldest and most common wideband codec in hardware uses the exact same 64 kbps before packet overhead. Most use much less, some dramatically less.

Want to know more about the specifics of various wideband codecs? Here’s something I posted a few months ago:

http://www.mgraves.org/voip/2009/05/mythbusting-hd-voice-frequency-response-vs-data-rate/

I see the same disinformation spreading in many circles where people have never actually used wideband voice.

“Also, users may have to invest in HD phones to get their full money’s worth.”

What kind of mealy mouthed wish-wash is that? If you want to experience a wideband call using a desktop phone you will need to buy one. That’s just common sense.

If you find a soft phone on your PC an acceptable alternative you might have to buy one of those. There are also open source & freeware options in that area.

“While HD compatible phones do exist, some argue that they don’t deliver full HD voice quality.”

More drivel. You had a point but failed to make it accurately.

Most wideband capable phones deliver real wideband quality calls. A few of the very cheapest might support a wideband codec for marketing purposes. It looks good on a tech sheet. But those same very cheap phones may not have the physical hardware quality to deliver a great sounding call.

The old Grandstream BudgeTone 200 is the classic example of this. While it supports G.722 you only hear an HD call on this phone using a headset. This is a simple case of getting exactly what you pay for.

“Even then HD to HD calls will be worthless if they have to travel over a traditional land line.”

Ahem, if the call path is via the PSTN then by definition it’s NOT an HDVoice call. HD calls require a pure IP media path. IP end-to-end. That usually means dialing by SIP URI.

In my case that means I have the pleasure of wideband calls between my associates desks. Also calls between offices routed via our WAN. Also calls home from a soft phone on my laptop to the Gigaset phones at my home.

We especially appreciate conference calls where its just simply easier to understand what’s being said.

Heck, my dogs even recognize my voice over a wideband call to a cheap little ClearOne Chat 50 speakerphone plugged into my wife’s PC.

I applaud your effort to be informative with this site. To be credible you need to do your homework about topics like HDVoice. If you’re not speaking from personal experience using HD they you’re not well positioned to comment.

This post has very little useful information except to express your personal lack of enthusiasm about HDVoice.
By fbnewman, July 28, 2009 @ 3:22 pm

Michael, in our attempt to make things understandable for the average VoIP consumer, it seems we may have oversimplified things a bit too much for some readers in terms of HDVoice. While it is true that we are still skeptical of the short term feasibility of wide-scale implementation of wideband voice, we did not mean to mislead any readers as to the realities of using the technology. In our attempt to simplify things it seems we’ve over-generalized a couple of issues and I’m glad you could call this to our attention.

The intention of the article was never to promulgate falsehoods about HDVoice, but merely to raise concerns about its current viability. The bottom line is that even if you have an IP phone that is capable or compatible with the technology, there are a large number of instances in which your calls will not in fact be wideband/HD quality. For this reason we feel that it is important consumers weigh the benefits of making the investment now while there are still so many variables to the equation.

I appreciate your further explanation of many of the technical terms of our post. However some of your criticism/consternation is a bit confusing, because despite pointing out what you label as “patently false” or “mealy mouthed wish-wash” you then seem to back-track and concede large parts of the points you’re arguing against. The main thing we wanted to make clear was that HDVoice/Wideband audio is not even remotely close to majority market penetration, and that there are significant changes that need to take place before many necessary elements are implemented on a widescale.