Android's UTC vs GPS Clock Error

Official Blog: Time, technology and leaping seconds

Google's Site Reliability Team blogged back in 2011 that "Having accurate time is critical to everything we do at Google."  This is an interesting statement, in light of the known issue with Android (i.e. Google) having a known clock error which equates to the difference between GPS Time and UTC Time. 

First reported back in 2009, the Android clock error is the result of the device's date/time being locked to the GPS time signals, but as I discovered and reported in 2010 the GPS driver fails to apply the time correction.  As of this writing the error is on the order of 15 seconds, and will increase over time.  The reason that GPS and UTC time differ is due to various factors, but the largest is that the two time systems are increasingly divergent due to "leap seconds" which are small corrections applied every couple of years to UTC time which attempt to keep the UTC year aligned with the "Solar year". 

You might argue that 15 seconds is not an issue, and for the majority of users this is true.  However for scientists, some professionals, and even amateur radio operators the error can cause huge problems.  In the amateur radio world we use smartphones to track the location of satellites and the International Space Station.  Depending on their orbit, most sats are visible in the sky for at most 15 minutes.  So the error in time means that an antenna pointed at the satellite will be incorrect by at least 3 degrees, possibly more. 

The thread on Android Google Code about this issue has grown quite long over the years.  I asked for users to report if their devices had the bug; over the years every post has been a "yes" with the one exception being a Nexus 4 running Android 4.2.1.  A response from the Android team has never been posted.  It would seem that "Having accurate time is critical to everything we do at Google" is a bit of a stretch - because clearly it's not even worth talking about when the inaccuracy is on Android.

Update: I picked up a Nexus 7 running Android 4.2.2 and find that the time issue is resolved!  So to be fair, the issue existed for a long time but "Jelly Bean" seems to have resolved the issue. 

Spectrum Analysis of a Smart Meter

We got our smart meter installed this past week, so of course I had to take a look at the RF signals coming from it. The results were very interesting!  I used the spectrum analyzer on an Anritsu S412E LMR Master™, which is fast enough to capture the 20 - 200 millisecond pulses in the 902 - 928 MHz ISM band coming from the PG&E electric smart meter (the meter itself was actually made by GE).

Summary of my findings?  As I expected, there's far more RF energy in the air from the TV and FM broadcast bands and cellular signals than from the smart meter's short-duration pulses.  You have to really hunt for the smart meter signals, which are buried underneath a lot of other stronger signals. 

The Un-Club: Validation

At ARRL Pacificon 2012 I presented "Club is a Four Letter Word" - during which I set forth the idea that most amateur radio clubs are hurting more than helping our hobby.  The thesis of my presentation was that, in the modern world where membership can be obtained by simply clicking the Like button on a Facebook page, and information on innumerable subjects can be obtained from YouTube and other sources, a traditional club structure is often not needed.  A recent article on the ARRL website entitled "The Un-Club" talked about many of these same ideas, and gave examples of how their group has rejected the traditional club model and the positive benefits from that approach. 

Consider Bay-Net in the San Francisco Bay Area.  It's increasingly one of the more popular amateur radio groups in the region, with a popular linked analog repeater system and D-Star node.  Bay-Net has no members; if you're on the email list, you're in the group.  Bay-Net doesn't hold regular meetings, except for a once-per-year gathering at which goals for the coming year are set forth for consideration and an informal expo is held where members bring in projects to share and discuss.  There are three "board members" (required to maintain the Bay-Net vanity callsign WW6BAY) but they're not treated any differently than anyone else and most of them group doesn't even know who they are.  We host a Field Day site every year and usually come in last place because we spend all of our time playing around with radios and gadgets instead of making contacts, but we always learn something. There are no dues; if we need to buy something we ask for donations and people step up. 

One of the great things about Bay-Net has been that it's attracted a lot of younger operators, which I credit in part to the "not a club" approach.  I encourage you to consider whether your club might be more efficient, more effective, and more inviting if it wasn't a club at all.

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Update: As if to yet again validate this idea, I received an email from a local club that allows non-members to monitor their mailing list:

We are having an election to make a change in the By-Laws. The proposed change is shown in RED LINE in the attached petition and adds the words "more than once" to the end of Article IV, Section 1 of the By-Laws. In essence the proposal is that the By-Laws be amended in order to allow officers to serve up to two one year terms in a row rather than only one term as presently provided. It would not extend officer terms and all officers would still stand for election each year at the April meeting.

Gaaahhhhh.....

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Update, Part II: I keep getting comments (here and on my G+ post) about the importance of f2f interaction and why clubs provide that.  Let me clarify: I'm not saying that Bay-Net never interacts f2f.  We meet up all the time, for a variety of reasons.  We just don't do it *formally*.  If we need or want to meet, we do.  What we don't do is waste time with minutes, financial reports, committee reports, voting, etc.

Narrowbanding: A Retrospective

The FCC-mandated deadline for narrowbanding is less than 100 hours away, and as was predicted many license holders will not make the deadline.  (e.g. New York City, Philadelphia, and Chicago)

Starting with a Notice of Inquiry in 1991, and ordered in 2004 (yes, it really took over 13 years for the gears of governmental progress to get from "should we do this?" to "we're going to do this") narrowbanding refers to the conversion of land mobile radio systems from 25 kHz channel spacing to 12.5 kHz spacing.  It was first formally considered in the 1991 NOI because, before cellular phones became affordable and widely available, land mobile radio spectrum in some areas was very scarce.  In many major cities during the 1980's and 1990's it was often impossible to add new channels. 

Dissolve (as they say in the movies) to late 2012.  Many commercial land mobile radio users have switched over to cellular, cellular push-to-talk, or even smartphone push-to-talk apps.  It doesn't make sense to pay an LMR repeater provider for something that has limited coverage, limited flexibility, and requires professional installation in a vehicle.  Yes, LMR works when disaster strikes, which is one of the reasons why amateur radio has kept non-cellular radio in its arsenal of disaster communication solutions.  For the average commercial user, cellular makes more sense operationally and financially.  So there's a lot more LMR spectrum to be had, and yet the narrowbanding mandate continues; a 2013 solution to a 1986 problem.

Why are we even bothering to continue?  There are a wide variety of possible reasons, the sum of which probably answers the question.  The government doesn't like to admit it made a mistake, or that its thinking is two decades behind the technology curve.  It wouldn't be fair to let some people off the hook, when others have already made the change.  (Although this doesn't hold up, because obviously big cities mentioned above ARE being let off the hook.)  And of course there's big money to be made in narrowbanding; the government charges a fee to modify a license, and the radio manufacturers charge taxes on sales of new radio equipment.

All of the above reasons would be perhaps excusable if the end result were something desirable like interoperability, but we're farther away from interoperability than we were 20 years ago.  (Ref: "Meeting the Interoperability Challenge", Witkowski, CMU DMI Workshop 2012)  At the same time the FCC has been beating the narrowbanding drum, it's also allowed proliferation of incompatible radio technologies into public safety communications.  So where before we had everyone on analog FM but at different frequencies, we now have FM, P25, NXDN, DMR, etc and the frequencies are still not aligned.  God forbid these people get hold of our healthcare system.  Oh wait...

Dynamic Spectrum Sharing & Amateur Radio

FierceWireless reported yesterday that the US FCC has issued a Notice of Proposed Rulemaking (FCC 12-148) that if enacted into law would allocate the 3550-3650 MHz band for use by small-cells.  Heralded by industry groups such as Wireless Internet Service Providers Association (WISPA) and the High Tech Spectrum Coalition (whose members include Apple, Alcatel-Lucent, Cisco, Ericsson, Intel, Nokia, Qualcomm, Research in Motion, and Samsung) the rulemaking will implement a dynamic spectrum-sharing architecture similar to that proposed for TV white space users.

Not discussed, but likely to become relevant over time, is the fact that the 3550-3650 MHz band sits right next to the Amateur Radio Service's 3300-3500 MHz allocation.  I've been saying for years that amateur radio is very likely to lose this band because it's almost never used.  Even here in the Silicon Valley, where hams tend to push the technology envelope, the band lies dormant.  I think we're seeing the beginnings of the end for amateur's "ownership" of the 3300 GHz band.  If FCC 12-148 moves to law, and the dynamic spectrum sharing model proves to be successful, it's not unlikely that the FCC will move to expand the allocation.

On the other hand this could wind up being a windfall to amateur radio, because dynamic spectrum sharing works both ways.  It could be that the amateur radio of the future will leverage spectrum sharing and allow operators to use frequencies currently unavailable.  This is more likely to be true in data networks than voice networks, but of course digital voice could also make use of dynamic spectrum sharing. 

Apple won't enable LTE until system is vetted - by Apple

Last week Telecoms.com reported that Apple is not releasing the iPhone 5 for sale by mobile operators until they've confirmed the system's performance.  Originally rumored back in October, and now confirmed by Swisscom; it puts Apple into a unique and unprecedented position of essentially holding an operator hostage until their network is up to Apple standards.

In a way this is understandable.  The days when you bought a phone from a carrier and then got support from that carrier are long gone.  If you're operating an iPhone 5 on Verizon and encounter problems, you're more likely to call Apple than Verizon for support.  So Apple, wanting to reduce support calls, needs to insist that the network perform adequately before approving products.  The operators may not like this (maybe even for ego reasons) but it makes sense.

The Daily shuts down - not unexpected - more to follow?

It was announced today that The Daily - an innovative electronic newspaper intended for tablets and web-enabled TVs - will be shutting down.  This was to be expected.  In an era where the consumer can essentially create for free their own newspaper from websites, search agents, RSS feeds, etc etc etc - why did News Corp think that they could charge so much for an electronic newspaper?  It's the classic "Old Think" problem of not understanding how to monetize online content.  You can't create a newspaper app (however well done it might be) and apply printed media concepts - the two are not the same.

While I have great affection for CQ Magazine (having written several articles for them in the past) I have been dismayed at how they've approached digital content.  Instead of creating an app that extends and amplifies the CQ reader experience, they've essentially scanned their print magazine and are trying to sell subscriptions to that which require a 3rd party "reader" app.  The problem is that the Zinio app only runs on Windows & Mac!  Want to kick back in your chair and read CQ on an iPad?  You can't do it.  Other content publishers do similarly silly things.  The IEEE for example has been diverting their readers away from printed magazines in favor of PDF downloads.  Which is actually better than Zinio, because at least Adobe Reader is available for some (but not all) tablet OSes. 

The broadcast TV industry is a good example of a better way.  Many of the Big Three affiliates (e.g. KGO ABC-7 in the SF Bay area) have created apps for both iOS and Android.  They're highly interactive and work very well.  Hopefully the print media folks will follow suit, or they're likely to end up in the recycling bin.

Update: Thanks to the folks who let me know via comments that Zinio does in fact have readers for iOS and Android tablets.  I should have checked the Zinio website directly, instead of relying on the CQ Magazine "Digital Edition FAQ" which lists only Windows and Mac OS.