AT&T Please fix tower 15932433

We spend a lot of time testing codec performance on real-life 4G networks. We've found several spots in cities that function well as worst-case scenarios, including the vicinity of the White House and Times Square. We've also found a good testing ground closer to home--the Boston Common. It's a wide open spot in the center of the city where you can count on changing cell towers pretty regularly as you walk around.

We had some interesting results yesterday while testing our LiveShot video codec there. We had three modems attached. (for you audio codec users, this capability is coming soon in firmware 4.0) Verizon and Sprint modems were champs, but depending on location our AT&T modem would behave miserably--to the point where it's presence was actually more of a hindrance to the overall stream than a help.

That was actually good news, since we were trying to tweak our algorithms to minimize or quarantine the data from a bad network. But we took it a bit further and started reading the stats on the modem as it entered and exited the "zone of doom". Sure enough, it was a discrete tower switch at the exact moment the channel fell apart.

The above graph illustrates the percentage of packet loss over time in one second intervals. When viewed on the product, this graph moves in real-time from right (most recent) to left (60 seconds ago). It's pretty obvious when you're on the bad tower.

Why is this particular cell so bad?  Is it located in a place where multipath is a problem on the Common? Is there a local transmitter with a spur in the 700MHz region blanking the cell tower receiver? I'm sure bribing an AT&T tech would be the only answer, and none were around.

In case you think this problem is specific to AT&T, we were at this exact location about 10 months ago, and AT&T was flawless throughout the area. But at that time, an identical situation occurred on Verizon, at the opposite end of the test area. Go figure.

Is POTS dead?

No profound insights or innovative solutions to talk about today. Just a bit of navel-gazing.

We're getting more and more war stories of broadcasters unable to find a "real" POTS line at a venue from which they need to broadcast. The phone jacks they used to rely on get terminated in a VoIP switch. POTS codecs rely on a very intricate modem balance on a phone line. And VoIP systems treat modems like a weed on a putting green-- A nuisance to be destroyed.

Of course the answer is "Go IP", but that's a pretty cold response to someone who doesn't have the budget for shiny new hardware. And IP codecs are still hot commodities hard to find on Ebay. POTS codecs are relatively easy and cheap to find there (possibly a testament to their demise?)

It's really hard to gauge how rough things really are-- we don't hear about the successes as often as the failures. But at a minimum it seems those who show up assuming that RJ-11 is connected to the CO by a pair of copper wires will be disappointed in short order.

I turned off my HD Radio today

I have always had an overall love of broadcasting and care a lot about radio, even in the sectors that don't affect Comrex directly. When the industry finally settled on HD Radio after what seemed like endless debate, I was very skeptical it would add the kind of value the proponents said it would. But I was willing to be proven wrong on that.

It was time for a new vehicle last summer. Being a frugal Yankee, I lean toward well reviewed but value-oriented cars. But being a techie I tend to upgrade those with some shiny options. It turns out one of those options this time around was HD Radio.

I wasn't surprised, given the dismal results of the HD Radio marketing campaign, that I had to teach the sales rep what it was and that it wasn't satellite. On this radio, HD is a global on/off setting i.e. you can't enable a couple of HD2 channels but disable HD1 switch-over on others.

Having had the family in the car now enough times, I made the decision to turn it off. I live about 30 miles from most of the Boston market's FM transmitters in Needham MA. It was result of two conversations. The first from my teenage son:

Him: Dad, why does the sound of the music keep changing?
Me; It's called HD radio. It's switching from old fashioned radio to digital. But the station set their sound processing so different on each side that it sounds like a different song whenever it switches..
Him: Can you make it stop?

The second was with my teenage daughter, listening to the local NPR affiliate:
Her: Why does the guy keep stuttering?
Me: It's called HD Radio. It's switching from analog to digital. But the station hasn't aligned the two signals in time correctly.
Her: Can you make it stop?

At no time was any advantage to HD noticed by any of my family. And HD2 channels are unlistenable in the suburbs. So I made it stop today.

What is WebRTC?

We've been discussing WebRTC a lot here over the last year, and sometimes you have to take a step back and make sure you've brought everyone up to speed. So here's a new little primer describing what it is and why it's important. Enjoy!

Microsoft is a little less evil today

Microsoft today has tipped its hand about the direction it intends to take Skype, and it's pretty good news for us. Besides a commitment to integrate WebRTC in Internet Explorer, they're now talking about integrating Skype with WebRTC.

The devil's in the details of course, but this bodes well for those of you missing Skype integration on STAC-VIP, and it means we may be able to eventually support it on codecs.

As a refresher, WebRTC is a real-time video audio codec built into modern web browsers. Using the right SIP carrier, it can make high quality calls to our ACCESS codec and STAC-VIP talkshow system from virtually any computer, using the high-quality Opus algorithm.

Think I'm kidding about changing default passwords?

I've raged before about people leaving their passwords at default.
I'm not kidding. And neither are the hackers.

Verizon obsoletes Pantech USB modems

If you go to the Verizon Wireless website today, you'll find the selection of 4G USB modems (the kind that work well with audio and video codecs) quite reduced. The UML290, and it's newer cousin UML295, have been given the ol' end-of-life treatment. The only remaining option is the Novatel 551L, which does the job but has a very quirky USB connector and doesn't support the new Verizon XLTE service.
USB modems are waning in popularity in general, in favor of Wifi Hotspots, so this isn't a big surprise. We're working on alternative plans but for now, UML295s are available for good prices on eBay. I've bought a bunch and they work very well. Just carry it down to the Verizon store and have them activate it. It gets you out of a 2-year commitment when you bring-your-own anyway. You can even put a prepaid sim into it for a one-time event. And Hotspots (or Jetpacks as Big Red calls them) also work well in conjunction with our codec Wifi adapters.

Edit 10/1/14: The Pantechs appear back on the VZW site today, although my contacts there maintain the ax has fallen on them. So get 'em while you can.