Hello again- the astronauts will hear everyone calling whether its split or simplex operation so why not make it simplex!
pat
On Fri, 11 Aug 2006, Ransom, Kenneth G. (JSC-OC)[BAR] wrote:
It sounds like your issue is not that split frequencies are bad but that multiple uplinks makes it difficult for the crew to listen to one uplink. ITU region regulations for ground station operations are the culprit. Space has no borders but Earth does so have of the problem is getting everyone to agree on a single uplink. Not everyone in the world has the same frequency allocations nor do they use the available spectrum in their region the same way.
The issue is not the 20-30 miles but the number of callers in the 2000 km wide footprint. The station has to listen to all of them. Since you can't hear all of them, it becomes difficult to know when someone is talking or not without guidance from the station operator.
In the MIR days, the crew did not have the luxury of near full time satellite communication that provides voice, email communication and an IP phone that lets them make phone calls. If the MIR crew wanted to talk to someone, they needed to use the ham radio or the Russian VHF space to ground system. The ISS crew has plenty of options to choose from when they want to communicate and it depends on the personality of the crew as to which ones get utilized.
Kenneth - N5VHO
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of McGrane Sent: Thursday, August 10, 2006 6:43 PM To: Manned space BBS Subject: [sarex] further late reply regarding ISS simplex
Greetings from patrick N2OEQ
Despite support of the present frequency scheme for the ISS I still wish to disagree with the policy of split operation with different phone uplinks.
Back when the MIR was up, the russians operated simplex and left the radio on to listen for callers. On several occasions, I called the MIR according to my tracking program and was rewarded several times with a response.
With two different uplink frequencies, the astronauts are less inclined to leave the radio on to listen for callers.
When there were several callers here on simplex responding to a CQ call from the MIR, we acted civilized and took turns and everyone made contacts so I dont buy the absolute need for split operation. Besides, how many callers could there be within 20 or 30 miles up to the horizon.
We've had years of robot like amateur radio on the ISS. How about loosening the ties!
Thanks for the soapbox..... pat
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