Answering A Few Questions About HDVoice

Some time ago over in the VOIP Forum at Broadband Reports there was an interesting thread about wideband telephony and it’s relationship to common ITSPs. The person who started the thread was surprised to find that they could not pass wideband audio between two accounts on the same SIP-based ITSP.

Lifespeed

Holy cow, I just tried to pass G722 and Speex wideband through voip.ms and it choked !! I can’t believe it, I thought they were supposed to be one of the more competent providers.

This person’s presumption was that if the call is between accounts at the same service provider it doesn’t traverse a media gateway, and so should support any desired codec. While the logic was basically sound, clearly this wasn’t the case as the person soon found out.

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IETF’s New Codec To Be Known As Opus

As someone who’s passionately involved spreading the gospel of HDVoice I’ve been following the mailing list of the IETF CODEC Working Group. They’ve been working towards a new IETF RFC on a brand new wideband codec standard.

Starting with four submissions from Broadvoice, SpiritDSP, Skype and Xiph.org I think that they have made startlingly good progress over the past year. The group has actually arrived at a solution that provides for a codec that is a hybrid of SILK and CELT. It was recently announced on the mailing list that this new hybrid codec is to be known as “Opus.”

At IETF78 in Nagasaki, Japan the working group met to further their efforts. There’s a good recording of the session that, amongst other things, gives considerable detail about the hybrid nature of Opus.

There has been close co-operation between developers at Skype and Jean-Marc Valin of Xiph.org, such that they already have sample code running and have conducted some structured listening tests. The results of the listening tests are reported to be excellent.

It’s very interesting how the hybrid codec works. It can leverage both CELT and SILK principles acting on different frequency bands to generate the most optimal audio for a given bit-rate. It supports a wide range of sample rates from 8 KHz (PSTN narrowband) to 48 KHz (production quality audio) and bit-rates from 8 kbps to 128+ kbps per audio channel.

Opus may have a huge role to play in our transition away from the legacy PSTN. It’s very encouraging to hear that the CODEC Working Group is progressing so quickly.

A Curious Pair: Skype & Traditional Broadcasters

As Skype has become more and more popular various other parties have tried to ride on their coat-tails, including old media companies like TV stations & broadcast networks. I know of at least one TV station that was clandestinely using Skype over broadband to “phone in” breaking news events. The station in question even went so far as to promote the fact that they were using Skype. They did so without prior permission from Skype, and were eventually asked to stop doing so by Skype’s lawyers.

TV stations have been doing “Live Remotes” for decades. Most often this involved using a vehicle equipped with microwave relay gear to send the video feed back to the station in real-time. Much effort goes into ensuring that the video signal looks good when it finally hits air. Larger TV stations or more important projects might merit the use of satellite transponder time to get the video feed back to the station via a satellite link, at considerable expense.

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Wired Headset Happiness: The Return Of ETY.COM

Despite the fact that I have a couple of very good wireless headsets I still find that a wired headset can be handy. This is true both in the office and on the road. While lately I’ve been traveling with a Plantronics Voyager Pro UC cordless headset I also keep an Etymotic ETY.COM wired headset in a my laptop bag.

I’ve mentioned the Etymotic ETY.COM wired headset previously. It remains my favorite wired headset for mobile use. It sounds great and has a boom that reaches around to the corner of my mouth, which is ideal for use in a noisy environment.

However, since I changed cell phones back in November 2009 I’ve not been able to use the ETY.COM with my cell phones. Whereas the Blackberry Pearl has a four conductor 2.5mm jack for the wired headset, the newer Blackberry Bold2 (9700) has a larger 3.5 mm headset jack. The ETY.COM doesn’t fit the 9700 without an adapter.

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Rich Tehrani on Cisco’s UMI

I don’t always agree with TMC’s Rich Tehrani, but with respect to Cisco’s UMI I do believe that he has the situation nailed when he posted, “10 Reasons Why Cisco Umi Telepresence Will Fail.” In fact, I think that stopping at ten was a kindness in Cisco’s direction.

There are so many players in this space that simply do consumer electronics better than Cisco that I simply can’t see UMI getting much traction in it’s current form. Starting with Logitech other companies will soon be in the space with better devices…better user experience…better support…better prices…just plain better.

And just in case you’re wondering about Google TV, well Rakesh Agrawal, CEO of Houston based Snapstream, has I think some very insightful thoughts on the matter.

Telepresence In The Home: Who’s On First?

Cisco today introduced umi, it’s effort to bring telepresence from the board room into the living rooms of the world. Umi (pronounced like “you me”) attaches to an existing HDTV via an HDMI connection and is said to support HD video calling.

Depending upon your available bandwidth umi can provide 720p or 1080i video streams. They quote 720p as requiring 1.5 mbps in each direction, while 1080 requires 3.5 mbps. Those numbers suggest the umi is not supporting the H.264 High Profile compression profile that Polycom has used on their systems. H.264 High Profile makes more efficient use of bandwidth, according to Polycom it’s bandwidth requirements are as little as half that of competitive systems.

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