Thanks Vince, I am not trying to grind an axe or be a luddite. I am concerned that the battle for spectrum sharing is far from over and the more tangible progress we can make with PAWS the better prepared we are. So I am trying to be pragmatic in suggesting we try to get a PAWS standard completed quickly and one that minimizes the push back from the incumbents. This means we need to be able to get the Regulators to be able to continue to support us. If I understand what you are suggesting, as a US TVWS database, then my band plan would be channels 2-51 and I would return a list of 2-51 channels. If the list of 2-51 was populated by either "off" or a "permitted use" then I have logically addressed the regulator concern. By implication anything outside of that list is outside my band plan. Therefore I have not only told you what channels you can use I have informed you why you can't use anything else (off = no permission, anything else is out of band plan). That seems like a reasonable compromise to me. Peter S.
From: Vincent Chen <[email protected]<mailto:[email protected]>> Date: Wednesday, September 25, 2013 12:09 PM To: Peter Stanforth <[email protected]<mailto:[email protected]>> Cc: Paul Lambert <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [paws] Spectrum encoding discussion Thanks for sharing your insights Peter. This is an opportunity to have the protocol be a bit more forward thinking than what current regulators are thinking. Let's try to focus on Gabor's question again of how to express "unavailability", but phrasing it differently. If we were to take the view that the Database provides responses for frequencies where the device may operate, then - Any frequency ranges missing for the response means the device "is not granted permission" to operate in those frequencies under the rules implemented by the Database Then is it still useful to distinguish why permission is not granted? (off vs outside band plan) If not, then Option a), simply having gaps in the frequency ranges would satisfy this use case. Is this a good compromise? -vince On Wed, Sep 25, 2013 at 5:01 AM, Peter Stanforth <[email protected]<mailto:[email protected]>> wrote: Lowering the power to meet the mask is the easy way you get a radio certified – thus permission to operate. How is that anything to do with the database - which is simply managing Regulator policy? The ruleset is going to tell you what masks and other operating parameters are acceptable within a regulatory domain. I can't imagine a Regulator allowing a database operator to manipulate the unintentional interference in adjacent channels. If it did why stop there? Why couldn't the database manipulate co-channel interference to nearby protected entities? I thought we had a fairly elegant and simple solution. The ruleset defines the box the device can operate in and the database provides a specific set of permitted channels/frequencies within that box based on the location, time, and type of device making the request. All with respect to the specific list of entities the database has been told to protect at that location at that time. One final comment and then I will rest my case. I have had conversations with several Regulators about this recently, and they do not like any notion that the database is "thinking" about the answer. In every case they have said something along the lines of "if the database does not explicitly give a device permission to use a channel the device is not allowed to use it". In every case they have gone somewhat further stating that if the database operation goes beyond this simple approach they think it highly unlikely that they will get cooperation from incumbents. If you don't believe me – go ask them! Which brings me back to my soap box. We want to get PAWS done so we can enable white space. In my humble opinion, the more time we spend pontificating and the more complex we make it we are likely to achieve the opposite. Peter S. From: Paul Lambert <[email protected]<mailto:[email protected]>> Date: Tuesday, September 24, 2013 2:48 PM To: Don Joslyn <[email protected]<mailto:[email protected]>>, Vincent Chen <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [paws] Spectrum encoding discussion In line below … speaking strongly in favor of "b" Gabor, I agree on possible renaming, if we want to specify unavailable channels. Please see comments inline. On Mon, Sep 23, 2013 at 12:56 PM, <[email protected]<mailto:[email protected]>> wrote: Vince, This proposal of yours below could potentially become very confusing. The message itself is named Available Spectrum Request, and you propose the Available Spectrum Response to include a bunch of channels with unspecified power levels, which are btw, not available channels. So far, we have 4 proposed ways to indicate unavailable channels: a) Not listing it, implicit unavailability This has the drawback of not distinguishing between being silent about a channel that is within the database's purview (channel off), and being silent about a channel that is outside the database's purview (out of scope for given ruleset). [DJ – Why should the database care about channels that are outside the scope of the ruleset specified by the radio? For example, if the specified ruleset is FCC-related, then why would I need to include Ofcom-related channels in the response? Am I missing something?] The rules have strict adjacent channel requirements. Meeting the spectral mask for the adjacent channels is one of the hardest parts for fielding real equipment. If the rules allow relative measurement of the adjacent channel energy, you can simply lower your transmit power to the point that you can meet the adjacent requirements. For a general White Spaces solution – it is critical to have knowledge for the full spectrum mask. The full spectrum mask includes adjacent non-allowed channels. RF channel usage are NOT a binary on/off or a simple transmit level. The mask has a specific contour that extends beyond the "allowed" channel. Transmitters will always send energy in more than the allowed channel! Paul b) List unavailable channels and specify the power limit, eg -56dbm Since the protocol should stand on its own, independent of any particular regulatory rule, do we really want to rule this out? In our interpretations of the FCC rules, for example, a Database is not prevented from doing this. [DJ – I’m still in favor of just using the implicit unavailability method described above in a). What value is there in providing a power level for an unavailable channel? If I’m the radio, I can’t use the channel, and I’m not going to intentionally transmit in that channel. This comment also applies to c) and d).] c) List unavailable channels and specify –inf as power limit "-Inf" is not really workable, because JSON does not allow Infinity or NaNs (http://tools.ietf.org/html/rfc4627), hence the d) proposal. d) List unavailable channels and do not specify any power limit So far, we have majority in favour of a), few people who could live or prefer c) and sort of consensus to strike out option b) from the list above. We’ll wait for more input on the list before declaring rough consensus for the question above; then we’ll go back to the original question on whether the encoding of spectrum profile should be option 1 or option 2. p.s. It looks to me, that if we want to specify unavailable channels, we may need to modify the names of the paws messages to ‘Spectrum schedule’ or sg along these lines. - Gabor -- -vince
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