nanog mailing list archives

Re: 60ms cross continent


From: Denys Fedoryshchenko <nuclearcat () nuclearcat com>
Date: Tue, 07 Jul 2020 07:40:10 +0300

On 2020-07-07 06:48, Eric Kuhnke wrote:
This is why adaptive coding and modulation systems exist. Also dynamic
channel size changes and advanced computationally intensive FECs.

You don't think people working on microwave band projects above 10GHz
with dollar figures in the hundreds of millions are unaware of basic
rain fade and link budget methodology, do you?

On Mon, Jul 6, 2020, 8:44 PM Denys Fedoryshchenko
<nuclearcat () nuclearcat com> wrote:

On 2020-07-07 05:04, joe mcguckin wrote:
Theoretically, Starlink should be faster cross country than
terrestrial
fiber.


Joe McGuckin
ViaNet Communications

joe () via net
650-207-0372 cell
650-213-1302 office
650-969-2124 fax

When there is no clouds.

In my experience, all that ACM has achieved is that when link becomes "slow" and if it rains outside, it means that it will be down completely after few seconds. Previously with CCM or DVB-S without 2, it simply disappear without warning.
And yes, I have and cheap and expensive Microwaves >10Ghz too.
ACM/VCM really helps if you want to live on the edge, milking each db, (edge of link budget, e.g. small antenna size, interference), and this is actually very important to increase profitability, especially in case of multipoint VSAT, but it is near useless against rain fade.


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