Hi Gerald, At least according to the FCC, a slave (Mode I) device may utilize channels that the master (fixed device) cannot use, see §15.707 and 15.712. Thus there are potential situations where the master cannot be assumed to know what channel the slave is using. Although this is a bit esoteric as the FCC is silent about what the slave might do on those channels, it is nonetheless included in the FCC regulations.
So I suggest we have no reason to overrule Ofcom requirements for channel usage information. Also Andy's choice of words does ensure that this information is not required to be used in every operational scenario. Kind Regards, Scott From: ext Chouinard <[email protected]<mailto:[email protected]>> Date: Tue, 6 Mar 2012 11:44:07 -0500 To: ext com <[email protected]<mailto:[email protected]>> Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [paws] WGLC for draft-ietf-paws-problem-stmt-usecases-rqmts-03: channel reporting Andy, Looking at your suggestions below, it seems that there is a need to define more precisely what a “slave” device is relative to its “master”. In my view, a slave can only use the same transmission channel as that used by the master to which it is associated (otherwise, master and slaves would not be able to talk to each other). As a consequence, the slave does not have to indicate to the master the channel on which it is operating since the master knows it and can provided it to the database e. Similarly, modern bidirectional communication systems between a master and a slave device assumes that there will be a transmit power control (TPC) loop between the two devices to minimize the required transmit power in various propagation environments. The driving device in this closed-loop process will be the master and as a result, the EIRP transmitted by the slave device will be known to the master as long as there is a known factor linking the power specification sent by the master to the slave and the actual EIRP transmitted by the slave. Such factor which is a constant for each device can be provided from the slave to the master once at association. As a result, the slave does not need to inform the master of its current (and provably continuously varying) EIRP since the master will havethis information from its TPC process and can provide it to the database onbehalf of the slave device. Gerald ________________________________ From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of [email protected]<mailto:[email protected]> Sent: Tuesday, 06 March, 2012 10:42 To: [email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]> Subject: Re: [paws] WGLC for draft-ietf-paws-problem-stmt-usecases-rqmts-03: channel reporting All Comparing the draft with the Ofcom requirements at http://www.cept.org/Documents/se-43/4161/SE43(12)Info03_Draft-UK-regulatory-requirements-for-white-space-devices-in-the-UHF-TV-band, I believe the WG draft is deficient in the area of reporting frequencies and powers actually used by masters and slaves (Ofcom requirements 3.18 and 3.19.8). Ofcom intends to collect this data to assesses the impact of aggregate interference into other services. It would also provide usage information (frequency in use) that would inform the operation of a kill switch capability. I suggest this deficiency can be remedied with the following changes: New P requirements (probably best placed following P.12): P.12bis: The protocol MUST support a channel usage message from the slave device to the master device. The channel usage message MUST include parameters as required by local regulatory requirement. These parameters MAY include device ID, manufacturer's serial number, channel usage and power level information. P.12ter: The protocol MUST support a channel usage message from the master device to the database. The channel usage message MUST include parameters as required by local regulatory requirement for the master and its associated slaves. These parameters MAY include device ID, manufacturer's serial number, channel usage and power level information. P.12qua: The protocol MUST support a channel usage message acknowledgement. New O requirements (probably best placed following O13): O.13bis: According to local regulatory policy, after connecting to a master device'sradio network a slave device MAY inform the master device of the actual channel usage. The slave MUST include parameters required by local regulatory policy, e.g. device ID, manufacturer's serial number, channel usage and power levelinformation. O.13ter: According to local regulatory policy, a master device MAY inform the database of the actual channel usage of the master and its slaves. The master MUST include parameters required by local regulatory policy, e.g. device ID, manufacturer's serial number, channel usage and power level information of the master and its slaves. New steps could be introduced into one or more use cases to cover these Ofcom requirements, e.g. new steps 6bis and 9bis in the hotspot use case at 4.2.1: 6bis. Prior to initiating transmission, if required by local regulation, the master/AP informs the database of the channel and power level it has chosen. This is repeated for each slave that associated with the master. 9bis. Prior to initiating transmission, if required by local regulation, the slave informs the master/AP of the channel and power level it has chosen, and themaster/AP relays this information to the database. - end of new text - For information, for those not accessing the url in the first paragraph of this email, the full Ofcom requirements leading to this new PAWS text are as follows: 3.18 After receiving instructions from a WSDB in relation to the maximum permitted EIRPs over the DTT channels, and prior to initiating transmissions within the UHF TV band, a master WSD mustcommunicate to the WSDB the following information: 3.18.1 The lower and upper frequency boundaries13 of the in-block emissions of the master WSD, and those of the in-block emissions of its associated slaves. A lower frequency will be specified as (470 + 8k + 0.2n) MHz, with the corresponding upper frequency specified as (470 + 8k + 0.2m) MHz, where 0 ≤ k ≤ 39, 0 ≤ n ≤ 39, 1 ≤ m ≤ 40, and n < m. 3.18.2 The maximum in-block EIRP spectral densities (in dBm/(0.2 MHz)) that the masterWSD, and its associated slaves, actually radiate between each reported lower frequency boundary and its corresponding upper frequency boundary. Footnote 13 states: The use of upper and lower frequency boundaries (defined over a 200 kHz raster) allows a WSDB to collect more granular information with regards to the usage of the frequency resource bynarrowband WSD technologies. The upper and lower frequencies of a boundary pair do not straddle a DTT channel boundary. Note that a WSD may transmit over multiple, non-contiguous, whole DTT channels or fractions of DTT channels. 3.19 A master WSD must be able to receive the following information14 from a WSDB: <snip> 3.19.8 [An acknowledgement from the WSDB, in the context of 3.18, that the reported information on the DTT channels and EIRP spectral densities actually used by the master and slave WSDs were received successfully by the WSDB18]. Footnote 14 states: 14 While the communication of some of this information from a WSDB to a master WSD is optional, master WSDs must be able to receive and interpret these. Footnote 18 states: 18 This forms part of a handshake protocol and may be an area where industry could harmonise without the need for an explicit requirement in the regulations. Regards Andy From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of [email protected]<mailto:[email protected]> Sent: 05 March 2012 19:46 To: [email protected]<mailto:[email protected]> Subject: [paws] WGLC for draft-ietf-paws-problem-stmt-usecases-rqmts-03 The authors of the use cases and requirements draft have just posted a new version of the draft and indicated that there are no unresolved comments/issues they are aware of. Therefore, I'd like to initiate a WG Last Call for comments on http://www.ietf.org/internet-drafts/draft-ietf-paws-problem-stmt-usecases-rqmts-03.txt Please review the draft and send yourcomments to the list by March 20th, 2012. If you review the draft and have no comments, send a note to the list that the draft is good as it is, we need these notes as much as we need the actual comments. Thanks, Gabor _______________________________________________ paws mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/paws
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