Thursday, December 27, 2012

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...


Friday, December 14, 2012

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. 

Monday, December 3, 2012

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.

Sunday, December 2, 2012

Disturbing GMRS Trend

Went it Frys to buy some walkie-talkies for the neighborhood kids. My girls often loan theirs out, and since I went high-end for them I wanted something less painful should they get damaged.

Problem is that it seems like most of the radios now don't come with CTCSS/DCS support. You have to go up into the > $50 range to get tone squelch. Midland seems to have more models at the lower range; from what I saw Uniden had almost none. The premium price seems like a lot, given that the code squelch support is likely already in the radio's ASIC. (It would make zero sense for the radio vendors to design more than one radio ASIC.)

I should probably note that I can understand the business motivation behind this. Most people who don't work with radio as amateurs or professionals are likely confused by CTCSS/DCS. The vendors made this problem worse by marketing it as a "privacy code" - customers likely call tech support all the time complaining that people can monitor their "private" transmissions. Eliminate the code, support call rates will go down. That doesn't mean it's a good idea.