[Starlink] Re: Starlink and Iran

Mike Puchol
2026-01-28T04:03:01Z

One clarification, nco = 8 means 8 co-frequency beams overlapping. If you have 8 different channels in Ku band, that’s a total of 64 possible beams per cell. This is a huge upgrade from the original nco = 1 for user/service beams (e.g. max 8 beams per cell).

Best,

Mike
On Jan 27, 2026 at 19:30 -0800, David Lang via Starlink <starlink@lists.bufferbloat.net>, wrote:
> Ulrich Speidel wrote:
>
> > Either way, it's worth noting here that while the relationship between
> > transmit power and and received power is linear, the relationship between
> > received power and achievable bit rate is logarithmic in nature. For those
> > not so mathematically inclined: Starlink is starting off with 64QAM (6 bits
> > per symbol) at current EPFD limits, and each extra bit beyond that requires a
> > doubling of the received power. Turning up the volume is not a game you can
> > stay ahead in for long, regardless of regulatory constraints.
>
> I think that the value in allowing higher radiated power at the receive end
> isn't to increase the bit rate from a single satellite, but to allow multiple
> satellites to cover the same area with the beam steering on the receiver
> differentiating between the satellites.
>
> allowing two satellites with significantly different angles to cover the same
> area allows for (close to) 2x the aggregate bandwidth to spread between all
> receivers in that area.
>
> > Some interesting tidbits from the grant document though:
> >
> > * 4. a. No more than 8 satellite beams "in the same frequency" (I
> > presume there's the word "band" missing here) into the same or
> > overlapping areas at a time. That means at most 8 beams per cell.
>
> if that's a step up from a single beam, that will allow for close to 8x the
> aggregate bandwidth.
>
> And if they can show (over time) that this doesn't cause problems, it will be
> reasonable to expect raising this limit over time
>
> it may be band, or it may be frequency/channel (like wifi has 3 bands, 2.4G, 5G,
> 6G), but 5G has many non-overlapping channels, and operating on multiple
> channels at the same time is quite reasonable for high-end APs
>
> > * 4. b. "SpaceX must maintain a minimum GSO arc exclusion zone of at
> > least four (4) degrees with respect to operational GSO satellites".
> > Finally a clear word?
>
> that geo exclusion has been in place for a while, but I thought it was a lot
> wider than 8 degrees (4 degrees to each side) I seem to remember hearing 25
> degrees being thrown around in discussions (I may very well be misremembering)
>
> David Lang
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