[GreenKeys] For all the telco and ex-telco guys

[Richard Knoppow]

----- Original Message ----- 
From: "Jim Haynes" <jhhaynes at earthlink.net>
To: "Richard Knoppow" <1oldlens1 at ix.netcom.com>
Cc: <greenkeys at mailman.qth.net>; <w8au at sssnet.com>
Sent: Monday, November 10, 2014 11:38 AM
Subject: Re: [GreenKeys] For all the telco and ex-telco guys


> On Mon, 10 Nov 2014, Richard Knoppow wrote:
>>   I wonder what the tall tower in the background is. It 
>> looks like either an AM station or perhaps the support 
>> for a TV or FM antenna. Hard to tell from the photos.
>
> What is a good location for a microwave tower is probably 
> also a good
> location for a broadcasting or cell phone tower
>
>>   I don't know how long the microwave network stayed 
>> alive but wonder if satellites would  not have supplanted 
>> much of it long before optical fiber.
>
> Satellites of the geostationary kind are disadvantageous 
> for voice
> conversations because there is a very noticeable time lag 
> between when
> the speaker stops speaking and the listener hears the last 
> of the
> speech.  And for satellites in low orbits you need either 
> a lot of
> satellites or a complicated tracking antenna system.

    For a single hop its about a third of a second, not too 
disturbing. Transoceanic telephone service was mostly via 
satellite once they were established.  Lots more bandwidth 
and better reliability than the formerly used radio 
circuits.  Voice cable for long links was not established 
until about 1958 and did not have a lot of capacity. The 
problem for satellite communication comes with multiple hops 
where the delay can become quite substantial.
    Of course with the current digital circuits we again 
have time delays because of the delays in encoding and 
decoding. Nothing is in real time any more.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com