Comments on: I have a cunning plan… https://tmfassociates.com/blog/2012/02/15/i-have-a-cunning-plan/ Satellites, spectrum and other stuff Tue, 03 Feb 2026 21:36:32 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: timfarrar https://tmfassociates.com/blog/2012/02/15/i-have-a-cunning-plan/comment-page-1/#comment-827 timfarrar Sun, 19 Feb 2012 14:31:55 +0000 http://tmfassociates.com/blog/?p=3114#comment-827 The NTIA test reports do show some concerns about interference from simulated handsets in the uplink bands. These would of course be magnified greatly by downlink operations at ~1500W compared to handsets at ~1W. In any case downlink operations in the uplink band are not permitted by current FCC rules and more importantly would not be allowed by Inmarsat because if the downlink signal happened to illuminate one of their satellites (which is looking for a much weaker signal from a satellite phone), it could overload and damage the satellite. As a result TD-LTE operations in the uplink band are simply not feasible The NTIA test reports do show some concerns about interference from simulated handsets in the uplink bands. These would of course be magnified greatly by downlink operations at ~1500W compared to handsets at ~1W.

In any case downlink operations in the uplink band are not permitted by current FCC rules and more importantly would not be allowed by Inmarsat because if the downlink signal happened to illuminate one of their satellites (which is looking for a much weaker signal from a satellite phone), it could overload and damage the satellite.

As a result TD-LTE operations in the uplink band are simply not feasible

]]> By: Serena https://tmfassociates.com/blog/2012/02/15/i-have-a-cunning-plan/comment-page-1/#comment-826 Serena Sun, 19 Feb 2012 10:02:33 +0000 http://tmfassociates.com/blog/?p=3114#comment-826 I wholly agree with your posts on this subject: It seems LS principals got themselves in something they hadn't really figured out (experienced radio engineers are a very rare breed nowadays) and then resorted to tactics that couldn't succeed. But I have read elsewhere that Tim Farrar has said that the value of LS spectrum is now about Zero. It's possible, but IMO not certain: It's the case if LS sticks to deployment of standard (FDD) LTE. But what about LS using the upper 20 MHz it has, which is not impacting GPS, to deploy a TD-LTE network (such as the one planned now by Clearwire?) It may have less capacity than an FDD network, but still, the spectrum would be then valued at possibly up to 4 Billion USD, wouldn't it? I wholly agree with your posts on this subject: It seems LS principals got themselves in something they hadn’t really figured out (experienced radio engineers are a very rare breed nowadays) and then resorted to tactics that couldn’t succeed.
But I have read elsewhere that Tim Farrar has said that the value of LS spectrum is now about Zero. It’s possible, but IMO not certain:
It’s the case if LS sticks to deployment of standard (FDD) LTE.
But what about LS using the upper 20 MHz it has, which is not impacting GPS, to deploy a TD-LTE network (such as the one planned now by Clearwire?)
It may have less capacity than an FDD network, but still, the spectrum would be then valued at possibly up to 4 Billion USD, wouldn’t it?

]]>