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. 


WiMAX Pro said...

David, the general rule of the road for access to spectrum in the heated environment of today is 'use it or lose it'. Incumbent areas where spectrum has been allocated but has seen a history of sporadic, low duty-cycle, or use only in specific geographic areas or such as in-building use (hospitals for example) can be subject to relinquishing or sharing access.

Its also possible to use the more advanced wireless technologies including LTE/LTE-Advanced based on the QoS, quality of service, priority access capabilities incorporated into the 4G technologies combined with improved signal sensing and control. This can allow an 'preferred sharing' of the spectrum that makes use of the same or very similar wireless ICs/SoCs, RFICS, etc. that help drive costs to consumer price levels. That helps to benefit the specialty classes of uses such as medical, public safety, military.

There is no reason why "Old Ham Radio" cannot now join the modern world to make broader use of the wireless spectrum. However, this obviously would require re-thinking the highly-powered personal use wide-band frequency use scenario. Instead, Ham would need to make use of less spectrum, perhaps 40-60MHz in ways that the current technology, including vast improvements in signal filtering, relaying, and multiple modes of operation, to provide an alternative mode of operation to Ham users. Ham use is to a large degree been overtaken by the Internet... your 'signal' travels across "whatever network to whomever user or device". Ham users might well consider advocating that their spectrum be made into a new common access band similar to Wi-Fi but designed for wider area coverage.. higher power and use of multiple tiers to provide local, middle-mile and wide area coverage.

If not, then prepare for the commercial industry to lay claim to the unused spaces of HAM radio.. the "BORG industry .. resistance is futile... you will be assimilated".

Richard Womersley said...

Changes in the way that Ham Radio is licensed should be discussed more widely as it's almost a given that some of the higher frequency bands (420 MHz to, say, 10 GHz) will come under intense pressure from commercial users. Indeed the 2.3, 3.4 and 5.6 GHz bands are in the process of being licensed for other services in many countries and in some cases (eg Australia) some bands have already been lost.

One of the good things about Ham usage is that at present it is often shared with other users (eg defence). It is the reticence of these users to move that permits Hams to remain in the bands. If these users move, Ham usage will not have sufficient economic value against wider wireless broadband use. The value of the spectrum that Hams are sitting on is also quite large (see the Wireless Waffle article on spectrum pricing for Hams for an example).

What would seem more sensible in today's increasingly pressured spectrum environment would be to allow Hams 'cognitive access' to spectrum using exactly the kind of sense-and-avoid tactics that Hams use anyway. Why not allow Hams to access any spectrum, anywhere subject to rules on interference restriction. This would open up new avenues of experimentation and would allow amateurs to provide useful data on sharing that could feed other applications.

The few remaining bands (eg 144 MHz) could be used to co-ordinate the cognitive access.

Just my 2 cent's worth.