[mod.telecom] EA problems

RONNIE@DEEP-THOUGHT.MIT.EDU (Ron S Schnell) (01/11/86)

It seems that whenever I (or anyone) uses SPRINT to dial ANY NUMBER in
NPA 305, there is a half second delay.  I have verified this by
counting into the phone and having the other person attempt to count
at thesame time.  This is really annoying and I have called SPRINT 
Customer Service several times but they just keep giving me credit for
the calls and it continues.  Does anyone have any idea why this happens?

Another (more serious) problem I have experienced, is that when I use
many of the LD svcs other than AT&T and a couple of others, after being
connected for a few seconds, the other person will dissapear for a
fraction of a second.  This makes it impossible for me to use my modem
because carrier gets lost after being connected.  This doesn't seem
to happen to all areas...617 is one of them.  The pitch of the static
seems to change after that happens too, and often a lot of the static
goes away.  

I would appreciate it if anyone could fill me in on what is happenning in
either or both of these cases.


				#Ron
				(ronnie%sutcase.bitnet@wiscvm)
				(ronnie%mit-eddie.arpa)
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GRUPP@MIT-MC.ARPA ("Paul R. Grupp") (01/12/86)

The half second delay you refer to is the time it takes to bounce a
signal off a 44Kmile orbit satelite. (186,000 Miles_per_Sec/(2*44,000
that's 1/4 sec up plus 1/4 sec back).

-Paul

telecom@ucbvax.UUCP (01/14/86)

Not that it matters, but I think it is 22,000 miles to
geosynchronous orbit. The delay is 1/4 second one way, but
the round trip ( which is important in echo situations )
is 1/2 seconds. I have heard that most long distance voice is
done by satellite in one direction and by microwave in the
other, this reduces the echo time to ~1/4 second and makes the
echo less annoying.

Mike