High Definition VoIP
On February 1st, 2007, Iristel introduced high-definition (HD) VoIP service in Canada, comparing the improvement in voice quality over most VoIP to CD-quality sound vs. AM radio.
Iristel’s announcement kicked off a debate in the telecom blogosphere: What exactly is HD VoIP, and do you need it? Is there no hope anywhere but Skype?
Ahh… Skype. Any discussion of HD VoIP quickly turns to Skype, and the question of why Skype-to-Skype calls sound so good. It’s because Skype uses a translation algorithm (a “codec”) called ISAC that captures 16 kHz of voice frequency, rather than the 8 kHz that regular publicly switched telephone network (PSTN) calls and most VoIP calls do. By capturing and transmitting this much wider range of voice frequencies, Skype’s voice quality is much more realistic.
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Its encouraging to see Skype using a unique codec such as ISAC. They are raising the bar on this VoIP standard and hopefully others will follow. Additionally, open source projects like Speex reinforced these innovations even more and will help businesses of all size.