Hi Ray, For example, in channels 37 and 39, OFCOM require Class 5 devices to > transmit at 11 dBm max, Class 4 at 21 dBm and Class 3 at 31 dBm, with no > constraints on Class 1 or 2.
This actually shows that Ofcom has picked a power threshold on channel 38 of -33 dBm. If you look at the ACLR numbers for class 3, 4, and 5 devices, you'll see they are 10 dB apart from each other and that they all work out to be -33 dBm on channel 38. The reason there are no limits for class 1 and 2 devices is because the in-band power on channels 37 and 39 cannot exceed +36 dBm/8MHz, and therefore the power on channel 38 will naturally be less than -33 dBm. Andy Lee | Google Inc. | [email protected] | 408-230-0522 On Thu, Sep 19, 2013 at 7:55 AM, Ray Bellis <[email protected]>wrote: > > On 19 Sep 2013, at 15:30, Vincent Chen <[email protected]> > wrote: > > > Perhaps this is a terminology issue. > > Perhaps :) > > > There must be some specification for emissions (intended or not) that > the device must meet during certification / testing. > > Indeed. The OFCOM / ETSI WSDB device<->DB interface only specifies > intended in-block emissions. > > All "Unintentional" out-of-block emissions are constrained by the ETSI > draft specification. > > > I believe you're focusing on intentional emissions, and Andy is speaking > to any emissions. > > That's my understanding. > > > I don't think it's reasonable to state that a device it must have 0W > -Inf dBm emissions at channel 38, if it intends to use any channels nearby? > > I disagree - OFCOM are stating 0W -Inf dBm *intentional* in-block > emissions at channel 38. > > They are not requiring that there be absolutely no emissions into channel > 38. Leakage from adjacent channels will be managed through a combination > of the device's emission class and OFCOM's rules on maximum permitted power > levels in those nearby channels. > > For example, in channels 37 and 39, OFCOM require Class 5 devices to > transmit at 11 dBm max, Class 4 at 21 dBm and Class 3 at 31 dBm, with no > constraints on Class 1 or 2. > > OFCOM have proposed that this is sufficient to ensure that the > unintentional leakage into channel 38 is not harmful to the PMSE devices > operating in that channel. > > kind regards, > > Ray > > _______________________________________________ > paws mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/paws >
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