Report: VOIM Sounds Better Than PSTN

Voice over Instant Messaging (VOIM) is a growing challenge to traditional TDM-based voice, a new Heavy Reading report finds. And one reason is that VOIM just sounds better.

VOIM clients such as Skype Ltd. mix IP voice with messaging, file transfer, and even video. VOIM services also detect "presence," or the availability of a person, device, or application to communicate.

In his report, Voice Over IM (VOIM) and How it is Changing Traditional Telephony, Heavy Reading analyst John Longo writes that those features, taken together, will eventually change the "communications paradigm." And traditional service providers, he suggests, will have to respond.

"Carriers will ultimately need to reconcile traditional telephony with VOIM as they face increasing pressure from their customers to receive the same types of flexible services" that VOIM enables, Longo writes.

The analyst explains that VOIM sounds better than TDM-based voice because it uses better-performing codecs, which convert analog signals into digital and back again.

The codecs used in TDM-based voice systems cover an 8kHz band directly in the middle of the voice frequency range, explains Global IP Sound AB CEO Gary Hermansen. (See GIPS Gets Patents.)

By contrast, Hermansen says, new IP codecs cover a 16kHz swath of the frequency range, which better conveys the highs, lows and texture of a caller's voice. Hermansen says VOIM codecs can also compensate for packet loss, and cancel out echo and background noise.

The end result is that VOIM makes the human voice sound more, well, human than traditional telephony ever did.

Hermansen's company has developed perhaps the most widely-used set of IP voice codecs among VOIM providers. Skype, Google (Nasdaq: GOOG) and Yahoo Inc. (Nasdaq: YHOO).)

But it doesn't have the market to itself, as Russian outfit Spirit Corp. has been making headway in the IP voice processing market. (See Spirit DSP Touts Deal and Trinity Licenses Spirit Tech.)

For more information on the report, click here.

— Mark Sullivan, Reporter, Light Reading

Mark Seery 12/5/2012 | 3:13:59 PM
re: Report: VOIM Sounds Better Than PSTN I'm no expert on this aspect, but something makes me think that the original range of frequencies that were provided for where some how related to the range that was engineered for on the analog access lines. Don't know if that was a limitation of the technology of the day (transformers, handset technology, etc.) or a design choice.....

At any rate, it seems to me the interesting question is as follows: given that skype has been using wideband/high fidelity codecs for many years already, how come U.S. domestic Skype calls often sound like crap (a statement of my personal experience only - though other people have said the same to me) while international calls sound great. I'd love to hear the explanation for that if any one knows it. If I had to guess, I would suspect it has to do with how the routing is being done, but I have no idea, that is just a wild guess. TIA if any one knows.
paolo.franzoi 12/5/2012 | 3:13:59 PM
re: Report: VOIM Sounds Better Than PSTN
CDs sound better than 8 tracks.

If you buy a high performance voice interface, you can get better performance off of the PSTN. Most of these devices are ISDN based and are used for things like remote radio stations.

The PSTN was designed for what it was designed for. It was not designed for the highest quality voice path, but instead one that was acceptable. Digital technology moved that bar and standardized it to the 64 Kb/s DS0. Ever notice how people now don't sound close or far away based on how far the phone call is?

materialgirl 12/5/2012 | 3:13:58 PM
re: Report: VOIM Sounds Better Than PSTN Voice is a feature, not a product. Once it moves to the application layer, you can do all sorts of fun things with it. Presence and follow-me, and better codecs are just starters. These inventions will never come from phone companies, however. They will do their best to stamp them out.

In the meantime, I have two questions:
PBT: Will this form of routing impair the peer-to-peer nature of traffic flows by forcing them over longer routes? I suppose of Skype works internationally, this is not a problem.

What happens to any-to-amy. Now you need to be on a company's list for IM. Our phone system achieved greatness because you could dial anyone. How will these closed IM systems impact an any-to-any world?
Mark Seery 12/5/2012 | 3:13:58 PM
re: Report: VOIM Sounds Better Than PSTN Well perhaps it was a bit of both:

"The bass frequency response is limted because of the limitations in telephone system components: transfromers and capacitors can be smaller if they don't have to deal with lowest frequencies. Other reason to drop out the lowest frequencies is to keep the possibly strong mains frequency (50 or 60 Hz and it's harmonics) hummign away from the audio signal you will hear." source: http://www.tkk.fi/Misc/Electro...

If you decide something is good enough, even if not perfect, and also economical, then it is a marriage of engineering and financials.......but after that marriage, you are stuck with the deal until you upgrade the contract........which has been happening since coax/dsl/fiber/....
Mark Seery 12/5/2012 | 3:13:58 PM
re: Report: VOIM Sounds Better Than PSTN MG,

The routing issue I was referring to was not related to either transport technology or IP relay technology, but to the location and architecture of VoIP processing (the application layer).
paolo.franzoi 12/5/2012 | 3:13:58 PM
re: Report: VOIM Sounds Better Than PSTN
There were studies done at the beginning of digitization of the network in the 50s and 60s about what was acceptable voice quality. Remember DS1s and DS3s went into the voice backbone starting in the early 60s. This led to the invention of the standard codecs including MG all the fancy CODECs. They were ALL invented by phone companies. Of course standards were introduced to make all the phones compatible, which is why you can call other folks.

So, it was a design choice based on what are known as MOS scores. It was done a LONG LONG time ago.

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