TELSTAR satellite experiment
hanc...@bbs.cpcn.com
multiple articles on the pioneer satellite. They explain the
background of the satellite and ground systems used and the results to
date of publication. Things such as power, bandwidth, antenna gain,
radio path loss, stability, beam focus, Van Allen belts, and orbit
parameters are covered in technical detial.
http://www.alcatel-lucent.com/bstj/vol42-1963/bstj-vol42-issue04.html
Tim Shoppa
Interestingly, QST (the ham radio magazine) was running non-amateur
articles on satellite communication and tracking in 1956, a year
before Sputnik. They like using the singular for "the satellite" (not
yet launched) which seems quaint in retrospect :-)
JUL 1956 - QST (PG. 38)
Radio Tracking of the Earth Satellite
Author: Easton, Roger L.
OCT 1956 - QST (PG. 46)
Receiver Bandwidth for Satellite Tracking
(Technical Correspondence)
Author: Wilkins, Paul E., W4SBA
OCT 1956 - QST (PG. 48)
Earth Satellite equipment - photo
Report a problem with this entry
NOV 1956 - QST (PG. 10)
Low-noise converter by Naval Research Lab for satellite-tracking
program
(Strays)
DEC 1956 - QST (PG. 42)
Low-Noise Preamplifier for Satellite Tracking, A
Author: Simas, V.R.
Quadibloc
> The July 1963 issue of the Bell Labs Technical Journal contains
> multiple articles on the pioneer satellite.
It gives one a sense of perspective to realize how far we have come
since then.
Today, communications satellites (almost all of which are in
geostationary orbit, unlike Telstar) are taken completely for granted.
At the time, on the other hand, Telstar captivated the imagination of
the world - even if somewhat less so than, say, John Glenn's orbital
flight.
There was even a hit instrumental tune which celebrated the satellite:
http://www.youtube.com/watch?v=YuA-fqKCiAE
and this particular guitar instrumental is historic, since, as I see
from the notes on this video, it was performed by a British group, The
Tornados, and yet achieved a #1 position on the Billboard hot 100...
in 1962, which was, of course, *prior* to the famous "British
invasion" which began in 1964.
John Savard
hanc...@bbs.cpcn.com
> Today, communications satellites (almost all of which are in
> geostationary orbit, unlike Telstar) are taken completely for granted.
> At the time, on the other hand, Telstar captivated the imagination of
> the world - even if somewhat less so than, say, John Glenn's orbital
> flight.
Would anyone know why Telstar was not in a geostationary orbit? That
would seem better for a communications satellite. One of the BSTJ
articles said it was in range of a tracking station only for about 20
minutes. Unless they shifted from one station to another, how could
that be used to TV programs and phone calls? (Or was a stationary
orbit too advanced for rockets of that day?)
When the early satellites were launched the newspaper would publish
the time and spot to see them pass by in the night, and people would
go outside to look for the moving dot.
When a _model_ of Telstar appeared in our local science museum, it was
a very popular exhibit.
From the point of view of someone who barely passed college physics,
the enormous calculations to get Telstar up there are utterly
amazing. We had a lab experiment where we shot a metal ball out of a
spring gun. It went across a grid screen lit by a blinking strobe
light, so it's path could be seen. Some of us had trouble with the
calculations (actually coming up with the integrals) to plot the
place. The physics for an orbiter were far more complex.
(As an aside, we had a mini computer and timeshared BASIC to do the
number crunching, but the hard part was establishing the formula.)
Patrick Scheible
> On May 18, 12:18=A0pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
>
> > Today, communications satellites (almost all of which are in
> > geostationary orbit, unlike Telstar) are taken completely for granted.
> > At the time, on the other hand, Telstar captivated the imagination of
> > the world - even if somewhat less so than, say, John Glenn's orbital
> > flight.
>
> Would anyone know why Telstar was not in a geostationary orbit? That
> would seem better for a communications satellite.
I read some hostile speculation about that as a monopoly with profits
guaranteed at a percentage of costs it was to AT&T's advantage to
adopt the most expensive technology possible.
-- Patrick
Paul
news:db18fda5-be78-4021...@c41g2000yqm.googlegroups.co
m:
> On May 12, 10:35 am, hanco...@bbs.cpcn.com wrote:
>> The July 1963 issue of the Bell Labs Technical Journal contains
>> multiple articles on the pioneer satellite.
>
> It gives one a sense of perspective to realize how far we have
> come since then.
>
> Today, communications satellites (almost all of which are in
> geostationary orbit, unlike Telstar) are taken completely for
> granted. At the time, on the other hand, Telstar captivated the
> imagination of the world - even if somewhat less so than, say,
> John Glenn's orbital flight.
As I was just getting to high school, Telstar seemed impressive to
me. You could watch it go by most any night, if you knew when and
where to look. Scince my father was an electrical engineer, we were
able to tour the Andover, Maine tracking station. It was in a rural
area, and had a huge tracking dish inside a dome. It is gone now,
there may be a little historical site sign.
--
Paul
Roland Hutchinson
> Would anyone know why Telstar was not in a geostationary orbit?
At a guess, you'd have to get it up six times higher to reach
geostationary orbit.
You need a bigger rocket booster (but that would have been manageable;
the first geosynchronous satellites went up shortly after TELSTAR), by
also, and you also (more likely the determining factor) need to have a
stronger radio signal (remember the inverse square law?) to achieve the
same bandwidth. Not so much of a problem for the ground stations, but
not so easy to get a bigger transmitter up into orbit and power it.
I wonder if the question is addressed in one of the BSTJ articles (which
I haven't yet read).
--
Roland Hutchinson
He calls himself "the Garden State's leading violist da gamba,"
... comparable to being ruler of an exceptionally small duchy.
--Newark (NJ) Star Ledger ( http://tinyurl.com/RolandIsNJ )
des...@verizon.net
> On May 18, 12:18 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
>
>> Today, communications satellites (almost all of which are in
>> geostationary orbit, unlike Telstar) are taken completely for granted.
>> At the time, on the other hand, Telstar captivated the imagination of
>> the world - even if somewhat less so than, say, John Glenn's orbital
>> flight.
>
> Would anyone know why Telstar was not in a geostationary orbit? That
> would seem better for a communications satellite.
If the satellite is being used for telephone,
geostationary is a big problem.
Unless you consider quarter second delays between sender and receiver
to not be a problem.
You can see it on nightly news when the talking head is talking to
someone in a foreign country when one sides asks a question and there
is a perceptible delay between question and answer.
Take the orbit height (22K miles) and divide by the speed of light
and magically, you get a significant number.
We even had satellite delays mess up our communications between
NJ and Houston. Our System 34s were running BI-SYNC and when the
call got routed to a satellite link the alternate ACK0/ACK1's would
get lost in the ether. IBM came in and adjusted something to make
the problem go away.
--
Dan Espen
D.J.
My parents and I went there. There was a small partial loop walkway
inside the dome. No tours or anything.
You could see the antenna and some of the equipment in another room. I
think there were a couple of plaques showing how often it came by,
orbit height, stuff like that.
JimP.
--
Brushing aside the thorns so I can see the stars.
http://www.linuxgazette.net/ Linux Gazette
http://www.drivein-jim.net/ Drive-In movie theaters
http://story.drivein-jim.net/ A story Feb, 2011
Anne & Lynn Wheeler
des...@verizon.net writes:
> If the satellite is being used for telephone,
> geostationary is a big problem.
>
> Unless you consider quarter second delays between sender and receiver
> to not be a problem.
>
> You can see it on nightly news when the talking head is talking to
> someone in a foreign country when one sides asks a question and there
> is a perceptible delay between question and answer.
>
> Take the orbit height (22K miles) and divide by the speed of light
> and magically, you get a significant number.
>
> We even had satellite delays mess up our communications between
> NJ and Houston. Our System 34s were running BI-SYNC and when the
> call got routed to a satellite link the alternate ACK0/ACK1's would
> get lost in the ether. IBM came in and adjusted something to make
> the problem go away.
early 80s, STL & Hursley were looking at off-shift load balancing
(i.e. 8hr difference) between the two locations. They setup to have
"hi-speed" (56kbit) over double-hop satellite (west coast up to
satellite, down to east coast, up to satellite over atlantic and down to
england) with VNET for initial tests. Everything worked fine ... so
pro-SNA forces insisted that the link be switched to JES2<->JES2
(instead of VNET<->VNET) ... resulting in absolutely nothing getting
through. Switched back to VNET<->VNET, and all files went through fine
with no problems.
The pro-SNA forces would then claim that there actually wasn't valid
signal getting through and VNET was "too dumb" to realize that there was
no signal.
I started doing HSDT project (high-speed data transport) starting
with T1, both terrestrial and satellite. misc. past posts
http://www.garlic.com/~lynn/subnetwork.html#hsdt
one of the issues for the internal network was all links had to be
encrypted ... in the mid-80s there was claim that internal network
had more than half of all link encryptors in the world
http://www.garlic.com/~lynn/subnetwork.html#internalnet
early on there were lots of issues with various gov. entities around the
world when internal network links cross national boundaries.
in the early 80s, hardware link encryptors were just about mandatory for
HSDT ... since simple software DES of T1 stream took full 3081K
processor ... and full-duplex T1 sustained transmission would take both
3081K processors. I had number of issues, T1 link encryptors were really
expensive, faster than T1 had to do custom hardware (wasn't any
off-the-shelf products) and any synch'ing link encryptors took
noticeable elapsed time ... even single bit error ... which was
significantly aggrevated by satellite propogations delay.
As a result, I got involved in designing encryption hardware that would
run significantly faster than T1, was significantly less expensive than
off-the-shelf products, and eliminated much of the resynch delay. Misc.
past references discovering there was 3-kinds of crypto:
http://www.garlic.com/~lynn/2008h.html#87 New test attempt
http://www.garlic.com/~lynn/2008i.html#86 Own a piece of the crypto wars
http://www.garlic.com/~lynn/2008j.html#43 What is "timesharing" (Re: OS X Finder windows vs terminal window weirdness)
http://www.garlic.com/~lynn/2009p.html#32 Getting Out Hard Drive in Real Old Computer
http://www.garlic.com/~lynn/2010i.html#27 Favourite computer history books?
http://www.garlic.com/~lynn/2010o.html#43 Internet Evolution - Part I: Encryption basics
another thing done for HSDT ... in part, motivated by satellite
propogation delay ... was developing support for rate-based pacing &
congestion control (as alternative to window-based pacing)
HSDT got a transponder on SBS4 ... and also invite to SBS4 launch that
went up on 41-d ... misc. past posts mentioning 41-d:
http://www.garlic.com/~lynn/2000b.html#27 Tysons Corner, Virginia
http://www.garlic.com/~lynn/2003k.html#14 Ping: Anne & Lynn Wheeler
http://www.garlic.com/~lynn/2004b.html#23 Health care and lies
http://www.garlic.com/~lynn/2005h.html#21 Thou shalt have no other gods before the ANSI C standard
http://www.garlic.com/~lynn/2006m.html#11 An Out-of-the-Main Activity
http://www.garlic.com/~lynn/2006m.html#16 Why I use a Mac, anno 2006
http://www.garlic.com/~lynn/2006p.html#31 "25th Anniversary of the Personal Computer"
http://www.garlic.com/~lynn/2006v.html#41 Year-end computer bug could ground Shuttle
http://www.garlic.com/~lynn/2007p.html#61 Damn
http://www.garlic.com/~lynn/2008m.html#19 IBM-MAIN longevity
http://www.garlic.com/~lynn/2008m.html#20 IBM-MAIN longevity
http://www.garlic.com/~lynn/2008m.html#44 IBM-MAIN longevity
http://www.garlic.com/~lynn/2009i.html#27 My Vintage Dream PC
http://www.garlic.com/~lynn/2009k.html#76 And, 40 years of IBM midrange
http://www.garlic.com/~lynn/2009o.html#36 U.S. students behind in math, science, analysis says
http://www.garlic.com/~lynn/2010c.html#57 watches
http://www.garlic.com/~lynn/2010i.html#69 Favourite computer history books?
http://www.garlic.com/~lynn/2011c.html#76 Other early NSFNET backbone
http://www.garlic.com/~lynn/2011d.html#61 End of an era
http://www.garlic.com/~lynn/2011d.html#77 End of an era
--
virtualization experience starting Jan1968, online at home since Mar1970
Roland Hutchinson
> hanc...@bbs.cpcn.com writes:
>
>> On May 18, 12:18 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
>>
>>> Today, communications satellites (almost all of which are in
>>> geostationary orbit, unlike Telstar) are taken completely for granted.
>>> At the time, on the other hand, Telstar captivated the imagination of
>>> the world - even if somewhat less so than, say, John Glenn's orbital
>>> flight.
>>
>> Would anyone know why Telstar was not in a geostationary orbit? That
>> would seem better for a communications satellite.
>
> If the satellite is being used for telephone, geostationary is a big
> problem.
>
> Unless you consider quarter second delays between sender and receiver to
> not be a problem.
Oh, yeah -- that, too.
But I seem to remember that we did put up with it when we made overseas
calls that went via satellite in, say, the 1970s. Do I remember right?
Tim Shoppa
> Would anyone know why Telstar was not in a geostationary orbit?
I'm falling off my chair laughing.
Would anyone know why I don't have a Hover Car, Jet Pants, and a
Teleportation Ray?
Tim.
Quadibloc
> Would anyone know why Telstar was not in a geostationary orbit? That
> would seem better for a communications satellite.
It certainly would be, in general.
Geostationary orbits are used for television broadcasting. As noted,
there are sufficiently long time delays in sending signals to and from
them that they are distracting in telephone conversations. (That
hasn't stopped them from being used that way, but now increased
transatlantic cable capacity has pretty well eliminated that.)
The orbit of Telstar was elliptical, so that it was farthest from the
Earth when over the Atlantic; this increased the proportion of the
time when it was usable for its intended purpose; and it was intended
to be part of a group of several satellites, providing continuous
availability. However, those plans didn't come to fruition, and the
satellite only functioned for a couple of years.
The booster used was able to launch a 180 pound satellite into LEO,
and Telstar weighed 171 pounds, so a geostationary orbit was not an
option - which is not surprising; Telstar was launched in 1962, and
thus was one of the very earliest satellites. The first geostationary
satellites came next year, however, with the launch of Syncom 2 in
1963.
John Savard
Nick Spalding
<cb2a9797-d96d-481e...@r35g2000prj.googlegroups.com>
on Thu, 19 May 2011 07:11:21 -0700 (PDT):
> On May 18, 10:48 am, hanco...@bbs.cpcn.com wrote:
>
> > Would anyone know why Telstar was not in a geostationary orbit? That
> > would seem better for a communications satellite.
>
> It certainly would be, in general.
>
> Geostationary orbits are used for television broadcasting. As noted,
> there are sufficiently long time delays in sending signals to and from
> them that they are distracting in telephone conversations. (That
> hasn't stopped them from being used that way, but now increased
> transatlantic cable capacity has pretty well eliminated that.)
I have recently talked on Skype, with video, with my two eldest
grandsons in Brazil and Australia respectively without any noticeable
delays so there is no way there is any satellite involved in data
transmission to either of those.
As one who was in the telegraph business in the days of the old single
wire, earth return, gutta-percha clad, copper submarine cables I am
delighted in the progress that has been made since I left that trade in
1954.
> The orbit of Telstar was elliptical, so that it was farthest from the
> Earth when over the Atlantic; this increased the proportion of the
> time when it was usable for its intended purpose; and it was intended
> to be part of a group of several satellites, providing continuous
> availability. However, those plans didn't come to fruition, and the
> satellite only functioned for a couple of years.
>
> The booster used was able to launch a 180 pound satellite into LEO,
> and Telstar weighed 171 pounds, so a geostationary orbit was not an
> option - which is not surprising; Telstar was launched in 1962, and
> thus was one of the very earliest satellites. The first geostationary
> satellites came next year, however, with the launch of Syncom 2 in
> 1963.
>
> John Savard
--
Nick Spalding
des...@verizon.net
> On Wed, 18 May 2011 16:31:10 -0400, despen wrote:
>
>> hanc...@bbs.cpcn.com writes:
>>
>>> On May 18, 12:18 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
>>>
>>>> Today, communications satellites (almost all of which are in
>>>> geostationary orbit, unlike Telstar) are taken completely for granted.
>>>> At the time, on the other hand, Telstar captivated the imagination of
>>>> the world - even if somewhat less so than, say, John Glenn's orbital
>>>> flight.
>>>
>>> Would anyone know why Telstar was not in a geostationary orbit? That
>>> would seem better for a communications satellite.
>>
>> If the satellite is being used for telephone, geostationary is a big
>> problem.
>>
>> Unless you consider quarter second delays between sender and receiver to
>> not be a problem.
>
> Oh, yeah -- that, too.
>
> But I seem to remember that we did put up with it when we made overseas
> calls that went via satellite in, say, the 1970s. Do I remember right?
Can't remember ever making an international call.
But I'd guess so.
--
Dan Espen
hanc...@bbs.cpcn.com
> > Would anyone know why Telstar was not in a geostationary orbit?
> the first geosynchronous satellites went up shortly after TELSTAR), by
> also, and you also (more likely the determining factor) need to have a
> stronger radio signal (remember the inverse square law?) to achieve the
> same bandwidth. Not so much of a problem for the ground stations, but
> not so easy to get a bigger transmitter up into orbit and power it.
>
> I wonder if the question is addressed in one of the BSTJ articles (which
> I haven't yet read).
The rocket power was certainly a limiting factor--they said the
satellite's size and weight was limited by the rocket.
I sense that Telstar pushed the start of the art in radio signal
strength and other factors as well.
But now I see why they did what they did.
Ahem A Rivet's Shot
Tim Shoppa <sho...@trailing-edge.com> wrote:
> On May 18, 12:48 pm, hanco...@bbs.cpcn.com wrote:
> > Would anyone know why Telstar was not in a geostationary orbit?
>
> I'm falling off my chair laughing.
>
> Would anyone know why I don't have a Hover Car,
Energy is too expensive and too hard to store.
> Jet Pants, and a
Jet packs have been built (as long ago as the 1960s), they turned
out to be horribly dangerous.
> Teleportation Ray?
Need new physics.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
hanc...@bbs.cpcn.com
> But I seem to remember that we did put up with it when we made overseas
> calls that went via satellite in, say, the 1970s. Do I remember right?
Delay time (and unwanted echo) was an issue Bell Labs experimented
with. A slight delay time was considered tolerable in the earliest
days since otherwise the new channel being offered was still superior
to what existed. There was a huge demand for capacity. They lowered
the voice bandwidth on the trans-Atlantic cable to squeeze in more
voice channels (as they did in WW II on the domestic toll line
network).
hanc...@bbs.cpcn.com
> I have recently talked on Skype, with video, with my two eldest
> grandsons in Brazil and Australia respectively without any noticeable
> delays so there is no way there is any satellite involved in data
> transmission to either of those.
The BSTJ is loaded with articles on Bell's Picturephone service,
including at least one special issue. An extensive amount of research
into the subscriber set (camera and screen), transmission, switching,
etc But Picturephone never developed into a market. I wonder if any
of that research paid off in other areas. (Bell offered conference
picturephone service which I think had some market in the business
community, though the customers had to go to a Bell facility.)
Is the Skype image jittery? From what I've seen on TV, such images
are rather jittery, and I myself would prefer to steady plain b&w
image than a color bouncy one.
Stephen Wolstenholme
<my.sp...@verizon.net> wrote:
>On Wed, 18 May 2011 16:31:10 -0400, despen wrote:
>
>> hanc...@bbs.cpcn.com writes:
>>
>>> On May 18, 12:18 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
>>>
>>>> Today, communications satellites (almost all of which are in
>>>> geostationary orbit, unlike Telstar) are taken completely for granted.
>>>> At the time, on the other hand, Telstar captivated the imagination of
>>>> the world - even if somewhat less so than, say, John Glenn's orbital
>>>> flight.
>>>
>>> Would anyone know why Telstar was not in a geostationary orbit? That
>>> would seem better for a communications satellite.
>>
>> If the satellite is being used for telephone, geostationary is a big
>> problem.
>>
>> Unless you consider quarter second delays between sender and receiver to
>> not be a problem.
>
>Oh, yeah -- that, too.
>
>But I seem to remember that we did put up with it when we made overseas
>calls that went via satellite in, say, the 1970s. Do I remember right?
I remember making a call to my Aunt in America from here in England
and it being as clear as a local call. Being a youngster at the time I
got quite excited about being able to watch US TV programs in England
but they were very disappointing due to the choice of programs. The
BBC programs made available in the USA was probably just as
disappointing to the vast majority of Americans. Things have improved
since and it's not just the technology.
Steve
--
Neural network applications, help and support.
Neural Network Software. www.npsl1.com
EasyNN-plus. Neural Networks plus. www.easynn.com
SwingNN. Forecast with Neural Networks. www.swingnn.com
JustNN. Just Neural Networks. www.justnn.com
Nick Spalding
<5bcb7470-3c9b-4012...@v31g2000vbs.googlegroups.com>
on Thu, 19 May 2011 09:27:27 -0700 (PDT):
No, it is steady. It is particularly good when talking to my son in
France who has a very good quality webcam. Both of the grandsons are
using whatever nastiness is built into their laptops. I only have a
cheap webcam myself but I have never asked how well they are all seeing
me.
--
Nick Spalding
hanc...@bbs.cpcn.com
wrote:
> I remember making a call to my Aunt in America from here in England
> and it being as clear as a local call. Being a youngster at the time I
> got quite excited about being able to watch US TV programs in England
> but they were very disappointing due to the choice of programs. The
> BBC programs made available in the USA was probably just as
> disappointing to the vast majority of Americans. Things have improved
> since and it's not just the technology.
Some cultural things do not travel well.
The US MTV took a popular British show, "Skins", and made it for the
US. Aside from getting nasty false publicity (it was accused of being
obscene which it was not), it had terrible ratings.
Many British shows find favor on public television stations. I'm a
big fan of Keeping Up Appearances, I love Hyacinth (happend to catch
"If It's Tuesday it must be Belgiem) and saw a much younger image in
that, but still the same character.)
Quadibloc
> I have recently talked on Skype, with video, with my two eldest
> grandsons in Brazil and Australia respectively without any noticeable
> delays so there is no way there is any satellite involved in data
> transmission to either of those.
There wouldn't be. In theory, a satellite link would be good enough
for web surfing, but the protocol would have to be converted - the TCP/
IP protocol is not very good for links with long delays, I had read
when searching for information on this topic.
And, of course, there have been news items about how fiber optic
undersea cables being disturbed have cut off Internet service to some
places. Satellites are being used as a cheap way to move television
programming around, but undersea cables, a Victorian-era technology,
has turned out to be a higher-quality data link.
Even if we don't use gutta-percha any longer.
John Savard
Patrick Scheible
> I remember making a call to my Aunt in America from here in England
> and it being as clear as a local call. Being a youngster at the time I
> got quite excited about being able to watch US TV programs in England
> but they were very disappointing due to the choice of programs. The
> BBC programs made available in the USA was probably just as
> disappointing to the vast majority of Americans.
I think we Americans got the better end of the deal.
-- Patrick
hanc...@bbs.cpcn.com
> And, of course, there have been news items about how fiber optic
> undersea cables being disturbed have cut off Internet service to some
> places. Satellites are being used as a cheap way to move television
> programming around, but undersea cables, a Victorian-era technology,
> has turned out to be a higher-quality data link.
FWIW, the BSTJ has many articles on undersea cables, including at
least one whole issue devoted to the first one. There's even a
detailed article on how they designed the cable ship Long Lines (if
you like ships read that one.) Also lots of articles on fibre optic
early development.
Do modern fibre cables have repeaters? If so, are they still built
under extremely high standards for long life?
Quadibloc
> Do modern fibre cables have repeaters? If so, are they still built
> under extremely high standards for long life?
I don't know for sure, but I would suspect so, because the cost of
dragging a cable off the floor of the sea hasn't exactly declined in
accordance with Moore's Law.
And they would need repeaters - losses in optical fibre do exist, and
it's a long way across the Atlantic.
What I recall, though, is that there were problems with the earliest
optical fibre cables because sharks attacked them, while they were
warned away by the electrical fields of old-style telegraph and
telephone cables with wires. I don't know if they solved it the
obvious way, by putting in some wire channels in the same cable with
fibre, or if they did something else about the problem.
John Savard
Quadibloc
http://en.wikipedia.org/wiki/Submarine_communications_cable
They use a single conductor down the center of the cable to power the
repeaters - so they're all in series - instead of two conductors with
them all in parallel. Well, I suppose if one fails, the cable goes
dark anyways, but that seems awfully confident.
They use very clear optical fibre, so the repeaters are spaced at
intervals like 100 km; erbium-doped optical amplifiers are noted as
being used. And the reason for using very expensive optical fibre of
high clarity is that the repeaters introduce distortion.
Which means they're linears, instead of actually taking the signal
going down a fibre, fully demodulating it into all its components,
sharpening up the pulses and synchronizing their clocks, and then
putting the signal back together again. Cuts the component count a
great deal - and, thus, increases the reliability (as does having
fewer of them).
John Savard
Roland Hutchinson
> On May 19, 1:07 pm, Stephen Wolstenholme <st...@tropheus.demon.co.uk>
> wrote:
>
>> I remember making a call to my Aunt in America from here in England and
>> it being as clear as a local call. Being a youngster at the time I got
>> quite excited about being able to watch US TV programs in England but
>> they were very disappointing due to the choice of programs. The BBC
>> programs made available in the USA was probably just as disappointing
>> to the vast majority of Americans. Things have improved since and it's
>> not just the technology.
>
> Some cultural things do not travel well.
>
> The US MTV took a popular British show, "Skins", and made it for the US.
> Aside from getting nasty false publicity (it was accused of being
> obscene which it was not), it had terrible ratings.
Was it as bad as the US remake of "Coupling"?
On the other hand, "All in the Family" and "Sanford and Son" did very
well--and more recently, of course, "The Office".
Quadibloc
> The US MTV took a popular British show, "Skins", and made it for the
> US. Aside from getting nasty false publicity (it was accused of being
> obscene which it was not), it had terrible ratings.
No doubt because, like the U.S. version of Big Brother, there was no
nudity.
John Savard
Charles Richmond
Because you are *trailing* edge technology, *not* leading edge
technology... ;-)
--
+----------------------------------------+
| Charles and Francis Richmond |
| |
| plano dot net at aquaporin4 dot com |
+----------------------------------------+
Stephen Wolstenholme
Many year ago I worked on a range of multi node computer systems that
use fibre cables to couple individual nodes together. The length of a
cable was limited before a repeater was used. I can't remember the
actual max length but it was over 1km.
Nick Spalding
on Thu, 19 May 2011 23:45:08 +0200:
> In article <b5526de5-ba83-405f...@j23g2000yqc.googlegroups.com>,
> Quadibloc <jsa...@ecn.ab.ca> wrote:
> >On May 19, 8:38 am, Nick Spalding <spald...@iol.ie> wrote:
>
> >There wouldn't be. In theory, a satellite link would be good enough
> >for web surfing, but the protocol would have to be converted - the TCP/
> >IP protocol is not very good for links with long delays, I had read
> >when searching for information on this topic.
>
> Actually, TCP works just fine; it just needs a bigger window, and
> the _WINDOWS_ implementation needs a registry setting to allow that.
>
> Many routers on such long delay lines use tcp spoofing to fix this.
>
> Or, they use insane tricks like sending payload and acks on
> different paths, where there is some terrestrial capacity
> available, and a much faster, but delay-prone satellite link.
>
> >And, of course, there have been news items about how fiber optic
> >undersea cables being disturbed have cut off Internet service to some
> >places. Satellites are being used as a cheap way to move television
> >programming around, but undersea cables, a Victorian-era technology,
> >has turned out to be a higher-quality data link.
>
> Well, the fiber optics is one of the really impressive applications
> of quantum mechanics. In single mode fiber the photon is kept
> confined in it's own wave; so it just moves straight on. Dispersion
> is reduced by around three orders of magnitude by this.
>
> In addution we multiplex from 8 to 160 different colours into
> the fiber. At the densest, each bit uses only around 3 hz worth
> of light. This aggregate speed is way beyond what any electronic
> driver can acheive.
>
> We amplify the signals every 40-70 kilometers, but we use doped
> fibers excited by lasers (google "erbium doped fiber", even if
> erbium is soooo 90's). We don't demultiplex the colours just
> because we need a simple amplification. We only need to
> regenerate the bits once every 1000 km or so.
The old C&W system regenerated the bits each time a message passed from
one cable to the next which would often be of that order of distance but
sometimes much longer. At one station I worked on in the Cocos Keeling
islands we had a cable to Rodriguez which is a distance of 3660 km
according to Google Earth. There were also a cable to what we still
called Batavia, now Jakarta, (1300 km) and two, one of them a fast
continuously loaded cable, to Cottesloe near Perth, West Australa (2950
km).
The Rodriguez cable was laid in 1902 and when I was in Cocos in 1952/3
it had had three repairs in its lifetime, one on the beach at Rodriguez
and two inside the lagoon at Cocos, the deep water section had never
been touched.
> We do with light what the Victorians never quite acheived
> with copper (the first properly working FM-muxed cables
> were post WW1 installations, a good two decades later).
>
> >Even if we don't use gutta-percha any longer.
>
> But we do. It is a material to keep the sharks from gnawing
> on the cables. (this is actually a problem. They sense the
> electric field)
>
> .. satellites are actually a LOT more expensive per bit for
> most locations. They are useful where no other infrastructure
> is in place, though.
>
> -- mrr
>
--
Nick Spalding
hanc...@bbs.cpcn.com
> What I recall, though, is that there were problems with the earliest
> optical fibre cables because sharks attacked them, while they were
> warned away by the electrical fields of old-style telegraph and
> telephone cables with wires. I don't know if they solved it the
> obvious way, by putting in some wire channels in the same cable with
> fibre, or if they did something else about the problem.
Would you know who owns and builds the overseas cables today? Today's
"at&t" is a much smaller company and not the same "Ma Bell".
Stan Barr
>
> Skype uses an offshoot of H.264, very similar to MPEG 4, and adapts
> to the available bandwidth. At around 230 kilobit you get viewable
> images, at 450 kilobit you get decent 15 fps 320x240, at 800 kilobits
> you get 25 fps.
>
> So, with a decent broadband line you should get reasonably good video.
>
> TV companies should investigate this.
They have. My mothers new tv has an ethernet connection, optionally
wireless, and BBC iPlayer etc. available.
--
Cheers,
Stan Barr plan.b .at. dsl .dot. pipex .dot. com
The future was never like this!
grey...@mail.com
> On May 18, 12:48 pm, hanco...@bbs.cpcn.com wrote:
>> Would anyone know why Telstar was not in a geostationary orbit?
>
> I'm falling off my chair laughing.
>
> Would anyone know why I don't have a Hover Car, Jet Pants, and a
> Teleportation Ray?
>
> Tim.
Well, the jet pants are doable. Eat lots of beans, face in direction
required, hold naked flame behind bum, and fart.
(May require removal of trousers, as in one happy occasion, the
demonstrators trousers went on fire)
--
greymaus
.
.
...
Charlie Gibbs
(Roland Hutchinson) writes:
> On Wed, 18 May 2011 16:31:10 -0400, despen wrote:
>
>> If the satellite is being used for telephone, geostationary is a big
>> problem.
>>
>> Unless you consider quarter second delays between sender and receiver
>> to not be a problem.
>
> Oh, yeah -- that, too.
>
> But I seem to remember that we did put up with it when we made
> overseas calls that went via satellite in, say, the 1970s. Do
> I remember right?
You still see it in news broadcasts involving overseas correspondents.
--
/~\ cgi...@kltpzyxm.invalid (Charlie Gibbs)
\ / I'm really at ac.dekanfrus if you read it the right way.
X Top-posted messages will probably be ignored. See RFC1855.
/ \ HTML will DEFINITELY be ignored. Join the ASCII ribbon campaign!
Charlie Gibbs
(Roland Hutchinson) writes:
> On Thu, 19 May 2011 10:52:12 -0700, hancock4 wrote:
>
>> Some cultural things do not travel well.
>>
>> The US MTV took a popular British show, "Skins", and made it for
>> the US. Aside from getting nasty false publicity (it was accused
>> of being obscene which it was not), it had terrible ratings.
>
> Was it as bad as the US remake of "Coupling"?
They did that? I don't want to think about it.
> On the other hand, "All in the Family" and "Sanford and Son" did
> very well--and more recently, of course, "The Office".
I haven't watch "The Office" much, but what I've seen seems to
have a British feel.
Charlie Gibbs
(greymausg) writes:
> On 2011-05-19, Tim Shoppa <sho...@trailing-edge.com> wrote:
>
>> On May 18, 12:48 pm, hanco...@bbs.cpcn.com wrote:
>>
>>> Would anyone know why Telstar was not in a geostationary orbit?
>>
>> I'm falling off my chair laughing.
>>
>> Would anyone know why I don't have a Hover Car, Jet Pants, and a
>> Teleportation Ray?
>
> Well, the jet pants are doable. Eat lots of beans, face in direction
> required, hold naked flame behind bum, and fart.
>
> (May require removal of trousers, as in one happy occasion, the
> demonstrators trousers went on fire)
Were you in that bar too? No, wait, that was beer farts...
Michael Wojcik
>
> Some cultural things do not travel well.
>
> The US MTV took a popular British show, "Skins", and made it for the
> US. Aside from getting nasty false publicity (it was accused of being
> obscene which it was not), it had terrible ratings.
Well, this is MTV we're talking about. It's not like "Skins" was being
remade under the auspices of, say, Showtime or HBO. Even Nickelodeon
has higher standards than MTV.
I'm generally pleased, thus far, with SyFy's remake of "Being Human".
But I've seen only a few bits and pieces of the original.
--
Michael Wojcik
Micro Focus
Rhetoric & Writing, Michigan State University
Michael Wojcik
> In article <ir4p5q$jqg$2...@dont-email.me>, my.sp...@verizon.net
> (Roland Hutchinson) writes:
>
>> Was it as bad as the US remake of "Coupling"?
>
> They did that? I don't want to think about it.
They did, and it was interesting, even if it was an utter failure as
entertainment - because the US episodes were changed very little from
their UK counterparts. But while the UK versions were generally quite
funny (even for US viewers who saw them on BBC America or the like),
the US ones fell flat.
As I recall, it was hard to pin down precisely what was wrong with the
US versions - I don't remember particularly bad acting or direction or
anything. It was more a case that the scripts were written with
conventions of UK television genres in mind, and those didn't match
the generic expectations for US television genres.
Michael Wojcik
> In article <b5526de5-ba83-405f...@j23g2000yqc.googlegroups.com>,
> Quadibloc <jsa...@ecn.ab.ca> wrote:
>
>> There wouldn't be. In theory, a satellite link would be good enough
>> for web surfing, but the protocol would have to be converted - the TCP/
>> IP protocol is not very good for links with long delays, I had read
>> when searching for information on this topic.
>
> Actually, TCP works just fine; it just needs a bigger window, and
> the _WINDOWS_ implementation needs a registry setting to allow that.
According to MSDN, as of Windows 2003, Window Scaling, RFC 1323
timestamps, SACK, and PAWS are all enabled by default. That should be
enough to handle long fat pipes.
But I haven't checked whether those options actually are enabled.
Which registry setting are you referring to?
Rod Speed
> Charlie Gibbs wrote
>> Morten Reistad wrote
>>> So, with a decent broadband line you should get reasonably good video.
>>> TV companies should investigate this.
> IME, TV companies are not in the business of delivering good video.
> Nor are broadcasters, networks, cable companies, etc. They're in the
> business of delivering the least-expensive product that they can
> convince people to pay for.
Not with FTA TV, particularly the public broadcasters.
> And, of course, a lot of people *are* delivering TV-grade (as opposed
> to, say, YouTube-grade) video over the Internet now: Netflix, Hulu, etc.
>> Why? They've worked so hard to convince people that 6 fps is sexy
>> that it'd be a waste to give them any more.
> Indeed.
> Personally, I'd be satisfied with 6 fps if they were 6 full frames,
> with no dropped blocks, and if the damn audio didn't keep cutting out.
> (Stupid oversubscribing cable companies...) Dropped audio bugs me
> about a zillion times more than dropped video, since audio's usually
> far more important to the narrative, in the shows I watch.
Quadibloc
> Would you know who owns and builds the overseas cables today? Today's
> "at&t" is a much smaller company and not the same "Ma Bell".
Not really. There's a British company, Cable and Wireless, which owns
a few of them, that I've heard of...
John Savard
Quadibloc
> > Quadibloc <jsav...@ecn.ab.ca> wrote:
>
> >> There wouldn't be. In theory, a satellite link would be good enough
> >> for web surfing, but the protocol would have to be converted - the TCP/
> >> IP protocol is not very good for links with long delays, I had read
> >> when searching for information on this topic.
>
> > Actually, TCP works just fine; it just needs a bigger window, and
> > the _WINDOWS_ implementation needs a registry setting to allow that.
>
> According to MSDN, as of Windows 2003, Window Scaling, RFC 1323
> timestamps, SACK, and PAWS are all enabled by default. That should be
> enough to handle long fat pipes.
>
> But I haven't checked whether those options actually are enabled.
>
> Which registry setting are you referring to?
In any case, the issue has to do with the "slow-start" way in which
TCP/IP responds to lost packets - treating them as due to congestion.
The protocol is not designed for a high-latency environment. Giving it
a bigger window may help, but the appropriate thing to do to obtain
efficient use of a link with a long delay, such as through a
geosynchronous satellite, _is_ to use a different protocol.
John Savard
Anne & Lynn Wheeler
Quadibloc <jsa...@ecn.ab.ca> writes:
> In any case, the issue has to do with the "slow-start" way in which
> TCP/IP responds to lost packets - treating them as due to congestion.
> The protocol is not designed for a high-latency environment. Giving it
> a bigger window may help, but the appropriate thing to do to obtain
> efficient use of a link with a long delay, such as through a
> geosynchronous satellite, _is_ to use a different protocol.
re:
http://www.garlic.com/~lynn/2011g.html#20 TELSTAR satellite experiment
or much of any latency enviornment. The same month that slow-start was
presented at ietf meeting ... acm sigcomm had paper on why slow-start
was non-stable in bursty enviornment. increasing bandwidth tends to
aggrevate bursty activity.
same ietf meeting there was presentation on number of bits outstanding
in gbit coast-to-coast terrestrial fiber link was about the same as
number of bits outstanding in T1 satellite link.
as previously mentioned that was one of the reasons for doing rate-based
pacing.
one of the congestion problems is multiple back-to-back packets arriving
at intermediate node. one of the issues in non-stable slow-start with
windowing paradigm ... was that returning ACKs can have a tendency to
"bunch" at intermediate node ... arriving at origin all at one time
... opening large window ... resulting in multiple back-to-back packets
being sent. slow-start doesn't actually directly space-out back-to-back
packets (just hoping that happens as side-effect of the slow-start
... which then is defeated by the vagaries of returning ACKs).
One of the trivial ways of doing rate-based pacing is dynamically
adjusting delay interval between packet transmissions (directly
controlling packet interval transmission). I periodically conjectured
one of the reasons for slow-start was the poor timing facilities of many
of the platforms of the period. Note that several newer protocols have
done various kinds of rate-based pacing &/or controlling inter-packet
transmission delay.
some past discussions on the subject:
http://www.garlic.com/~lynn/2003g.html#44 Rewrite TCP/IP
http://www.garlic.com/~lynn/2003g.html#45 Rewrite TCP/IP
http://www.garlic.com/~lynn/2003g.html#54 Rewrite TCP/IP
http://www.garlic.com/~lynn/2003j.html#1 FAST - Shame On You Caltech!!!
http://www.garlic.com/~lynn/2003j.html#46 Fast TCP
http://www.garlic.com/~lynn/2004k.html#19 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#8 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#9 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#12 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#13 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#16 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#17 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2004k.html#18 FAST TCP makes dialup faster than broadband?
http://www.garlic.com/~lynn/2007n.html#37 FastTCP Commercialized Into An FTP Appliance
--
virtualization experience starting Jan1968, online at home since Mar1970
hanc...@bbs.cpcn.com
> Not really. There's a British company, Cable and Wireless, which owns
> a few of them, that I've heard of...
Gee, C&W dates way back to telegraph days. They used to own isolated
islands (maybe still do) as repeater stations.
Nick Spalding
<fd6a098b-df04-4c3c...@e13g2000vbo.googlegroups.com>
on Fri, 20 May 2011 19:18:28 -0700 (PDT):
I don't think they owned many of them but they certainly leased space on
them. I mentioned a couple of them elsewhere in this thread. Most of
the C&W cables were inherited from the Eastern Telegraph Company and its
associated companies. At the time I worked for them there were a
considerable number of cables laid in the 1800s still in use.
--
Nick Spalding
Ahem A Rivet's Shot
"Rod Speed" <rod.sp...@gmail.com> wrote:
> Rod Speed wrote
> > Ahem A Rivet's Shot wrote
> >> My point is that while this is indeed difficult it is not as difficult
> >> as making something that flies and runs at better than 30mpg.
>
> > Thats just plain wrong. There are plenty of cars that do better than
> > 30mpg buyable right now.
>
> I obvious meant
>
> Thats just plain wrong. There are plenty of planes that do better than
> 30mpg buyable right now.
I confess to considerable surprise, can you point me at examples ?
> >> I *am * in Europe and we certainly have gone the route of *not* flying.
>
> No you havent, there is more flying going on in europe than there has
> ever been.
I was obviously referring to flying in cars not airliners.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
grey...@mail.com
Newspaper article on C&W a while back reported them as being
still very busy installing lines, but their research (C&Ws)
was showing that they expected the maarket to be oversupplied.
Walter Bushell
Ahem A Rivet's Shot <ste...@eircom.net> wrote:
>
> One aspect of suitable is very likely that the thing won't fly
> under manual control at all.
And in science fiction autocontrol is done, especially in congested
areas. Approaching a town one turns over control.
Maybe over the badlands one can fly manually, with a special license.
--
The Chinese pretend their goods are good and we pretend our money
is good, or is it the reverse?
Dave Garland
> Michael Wojcik wrote:
>>
>> Personally, I'd be satisfied with 6 fps if they were 6 full frames,
>> with no dropped blocks, and if the damn audio didn't keep cutting out.
>> (Stupid oversubscribing cable companies...) Dropped audio bugs me
>> about a zillion times more than dropped video, since audio's usually
>> far more important to the narrative, in the shows I watch.
>>
> all the time...at least with the few stations I can get. I still
> can't get the digital channels I used to before the switch.
> My mother can off-hours. Last month, reception is "no signal"
> from 7:00-17:00. Can digital TV signals be [can't think of the
> word now] interferred with?
>
It sure can. (Also can be too weak.) And the quality does not
degrade gracefully, as with analog. It's a very short step from
"perfect" to "nothing at all".
FWIW, if you don't have a rooftop antenna (and perhaps a rotator, if
the stations aren't all in the same direction), you might find that
would help a lot. Even here (in the middle of a sizeable metro area,
so we're a lot closer to the stations than you are) set-top antennas
don't work anywhere near as well for digital as they did for analog.
Dave
Ahem A Rivet's Shot
Walter Bushell <pr...@panix.com> wrote:
> In article <20110521090833....@eircom.net>,
> Ahem A Rivet's Shot <ste...@eircom.net> wrote:
>
> >
> > One aspect of suitable is very likely that the thing won't fly
> > under manual control at all.
>
> And in science fiction autocontrol is done, especially in congested
> areas. Approaching a town one turns over control.
Yes - noting carefully that in this context "Star Wars" and "Fifth
Element" do not qualify as Science Fiction
Stan Barr
Cobble & Witless still run cables all over the world. Still basically
the same routes as in Victorian times - and still the same undersea
choke points vulnerable to dredging :-)
--
Cheers,
Stan Barr plan.b .at. dsl .dot. pipex .dot. com
The future was never like this!
Quadibloc
> Still basically
> the same routes as in Victorian times -
Well, basically the same countries are rich and powerful, and ocean
topography hasn't changed much in the last 200 years either.
John Savard
Rod Speed
> Rod Speed <rod.sp...@gmail.com> wrote
>> Rod Speed wrote
>>> Ahem A Rivet's Shot wrote
>>>> My point is that while this is indeed difficult it is not as difficult
>>>> as making something that flies and runs at better than 30mpg.
>> Thats just plain wrong. There are plenty of planes that do better
>> than 30mpg buyable right now.
> I confess to considerable surprise, can you point me at examples ?
All the ultralights.
>>>> I *am * in Europe and we certainly have gone the route of *not* flying.
>> No you havent, there is more flying going on in europe than there has ever been.
> I was obviously referring to flying in cars not airliners.
I wasnt talking about airliners, just GA flying. That hasnt stopped in europe.
Rod Speed
> Michael Wojcik wrote
>>> (Morten Reistad) wrote
>>>> So, with a decent broadband line you should get reasonably good video.
>>>> TV companies should investigate this.
>> IME, TV companies are not in the business of delivering good video.
>> Nor are broadcasters, networks, cable companies, etc. They're in the
>> business of delivering the least-expensive product that they can
>> convince people to pay for.
>> And, of course, a lot of people *are* delivering TV-grade (as opposed
>> to, say, YouTube-grade) video over the Internet now: Netflix, Hulu, etc.
>>> Why? They've worked so hard to convince people that 6 fps is sexy
>>> that it'd be a waste to give them any more.
>> Indeed.
>> Personally, I'd be satisfied with 6 fps if they were 6 full frames,
>> with no dropped blocks, and if the damn audio didn't keep cutting
>> out. (Stupid oversubscribing cable companies...) Dropped audio bugs
>> me about a zillion times more than dropped video, since audio's usually
>> far more important to the narrative, in the shows I watch.
> Perhaps I won't buy cable if that happens. Over-the-air does that
> all the time...at least with the few stations I can get. I still
> can't get the digital channels I used to before the switch.
> My mother can off-hours. Last month, reception is "no signal"
> from 7:00-17:00. Can digital TV signals be [can't think of the
> word now] interferred with?
Yes, but its much less of a problem than with analog TV.
If those times are reasonably reliable, its much more likely
they are turning it off during those times for some reason.
Rod Speed
We get the exact opposite effect, set top antennas that arent viable
for analog TV work fine with digital TV.
Rod Speed
> Stan Barr <pla...@dsl.pipex.com> wrote
>> Still basically the same routes as in Victorian times -
Thats just plain wrong, particularly in asia.
> Well, basically the same countries are rich and powerful,
No they arent, most obviously with china and taiwan etc.
> and ocean topography hasn't changed much in the last 200 years either.
Yes, but where its possible to do an undersea cable has.
Rod Speed
> Rod Speed <rod.sp...@gmail.com> wrote
>>>> Still basically the same routes as in Victorian times -
>> Thats just plain wrong, particularly in asia.
> Well, the most important Internet exchange point
> for the Spanish speaking world is in Miami.
And there was nothing like that there in Victorian times.
> In Asia everything used to center on japan, Hong Kong and
> Singapore, plus outlying lines to Australia and New Zealand.
That last isnt correct with Australia.
> That is in principle the current layout,
No it isnt, most obviously with the trans pacific cables with Australia.
> except Hong Kong and Singapore now have some competition
> from Mainland China, mostly Shanghai, and Singapore has acted
> up so much that telcos now choose Malaysia or even Riau in
> Indonesia as core locations. And South Korea has followed Japan.
And that is nothing like the situation in Victorian times.
> But otherwise the pattern is very unchanged.
Thats just plain wrong, particularly with the trans pacific cables.
> The area from India to Israel is a huge cable void. But this has
> been so since Churchill lamented about this around 1920 simetime.
Sure, SOME areas arent very different from Victorian times.
>>> Well, basically the same countries are rich and powerful,
>> No they arent, most obviously with china and taiwan etc.
>>> and ocean topography hasn't changed much in the last 200 years either.
>> Yes, but where its possible to do an undersea cable has.
> Possible, yes. We have high-capital, hugely expensive
> long fibers across the atlantic and across the pacific.
And the pacific particularly is quite different to what was possible in victorian times.
> But the bulk of the commercial cables does not look much different.
Looks very different in fact with the pacific.
> Africa has decent capacities only with coast-hopping sea cables.
> South America is connected to a huge Caribbean ring system,
> and through half a dozen transatlantic lines to Spain, half of
> which try to island-hop at least part of the way.
And thats nothing like what was there in Victorian times.
> The Trans-Siberian railway carries a lot of fiber alongside,
> but that route had telegraph conenctions before 1901 too.
Yes, but that isnt Victorian times.
> So, there has been a huge technology shift,
And some routes like the pacific that werent practical in Victorian times are now.
> but the geography is pretty much the same.
Yes, but what can be dont isnt, most obviousy with the pacific.
> Even SeaMeWe is tightly controlled by France.
That isnt the case with the pacific.
Dave Garland
> Dave Garland wrote:
>> FWIW, if you don't have a rooftop antenna (and perhaps a rotator, if
>> the stations aren't all in the same direction), you might find that
>> would help a lot. Even here (in the middle of a sizeable metro area,
>> so we're a lot closer to the stations than you are) set-top antennas
>> don't work anywhere near as well for digital as they did for analog.
>
> We get the exact opposite effect, set top antennas that arent viable
> for analog TV work fine with digital TV.
>
Interesting. There are a lot of variables (frequency band,
transmitter power and antenna patterns, number of subchannels, and
indeed the television system itself) that are probably different
between our areas. Here, stations that were marginal (some snow)
before become "NO SIGNAL", and stations that were slightly better get
video that freezes, jitters, bands in a cubist sort of way, drops
audio. I get fewer usable stations, but more channels (because each
station has 2-4 subchannels).
But in the US about 60% of households get their TV by cable, and
satellite is also common (just judging from the presence of antennae,
I'd guess 10% or more). The government wanted to sell off the analog
spectrum, the hardware makers wanted to sell more new kit, the
stations wanted to have the subchannels, and I suspect that nobody
gave a damn about the households that get it over the air. In the
metro, a number of people have told me that they had to install
rooftop antennae, or get cable, when we switched over to digital. In
my case, of the 5 primary (network) channels I got, I've lost 2 of
them (one totally, and one due to artifacts), though the ones that are
left have multiple subchannels, and I've picked up a few new
(non-big-network) ones including 5 subchannels of "All Catholic, All
The Time".
But I don't watch TV often, so it's not a big deal.
Dave
Rod Speed
> Rod Speed wrote
>> Dave Garland wrote
>>> FWIW, if you don't have a rooftop antenna (and perhaps a rotator,
>>> if the stations aren't all in the same direction), you might find that
>>> would help a lot. Even here (in the middle of a sizeable metro
>>> area, so we're a lot closer to the stations than you are) set-top
>>> antennas don't work anywhere near as well for digital as they did
>>> for analog.
>> We get the exact opposite effect, set top antennas that arent viable
>> for analog TV work fine with digital TV.
> Interesting. There are a lot of variables (frequency band, transmitter
> power and antenna patterns, number of subchannels, and indeed the
> television system itself) that are probably different between our areas.
I dont believe that anything except the band and power are relevant.
Ours are all UHF and the same transmitter power as the anlog channels
which are mostly VHF. I gather that many of the US digital transmitters
are well down power wise compared with the analog channels, ours arent.
> Here, stations that were marginal (some snow) before become
> "NO SIGNAL", and stations that were slightly better get video
> that freezes, jitters, bands in a cubist sort of way, drops audio.
We get the opposite effect, what wasnt usable with analog is perfect with
digital, presumably because of the different transmitter powers we use.
> I get fewer usable stations, but more channels
> (because each station has 2-4 subchannels).
We went for a lot more channels as we went to digital, and our
system is much more govt controlled than the american system.
> But in the US about 60% of households get their TV by cable,
Its nothing like that here, some controvery about whether the cable passes
anything like 30% of households, and nothing like that takeup rate.
We are supposed to be having FTTP to 93% of households, at a cost
of something like $50B, govt monopoly until it gets sold off, but it looks
almost certain that the govt stupid enough to go that route cant last
more than 2 years, its currently a minority govt, and when the voters
pull the plug on that govt the alternative govt plans to pull the plug on
the NBN. That will operate as a cable service as well as 1Gb net if it
ever does get built, because the current govt locks in the contracts etc.
> and satellite is also common
Yeah, thats pretty common here too.
> (just judging from the presence of antennae, I'd guess 10% or more).
Ours would be higher than that, but there arent that
many that use if for FTA TV except in remote areas.
> The government wanted to sell off the analog spectrum, the hardware
> makers wanted to sell more new kit, the stations wanted to have the
> subchannels, and I suspect that nobody gave a damn about the
> households that get it over the air.
They do here, with the federal govt with a hare brained scheme to
give govt pensioners, the equivalent of your SS people, getting a
$300 free set top box and new antenna if needed and 1 year warranty.
Completely insane when a brand new digital TV doesnt cost that.
> In the metro, a number of people have told me that they had to install
> rooftop antennae, or get cable, when we switched over to digital. In
> my case, of the 5 primary (network) channels I got, I've lost 2 of them
> (one totally, and one due to artifacts),
I didnt lose any. I still use the analog antenna but could use and indoor
antenna fine. Just didnt bother because I had the rooftop antenna.
> though the ones that are left have multiple subchannels, and I've picked up a few
> new (non-big-network) ones including 5 subchannels of "All Catholic, All The Time".
We dont have anything like that here, just the 5 main FTA channels,
two of them govt channels, each with their own subchannels, mostly
4 each. Thats Australia for those that dont know where I am.
> But I don't watch TV often, so it's not a big deal.
I do watch docos and news, very rarely ever watch any fiction or movies at all.
Roland Hutchinson
> Charlie Gibbs wrote:
>> In article <ir4p5q$jqg$2...@dont-email.me>, my.sp...@verizon.net
>> (Roland Hutchinson) writes:
>>
>>> Was it as bad as the US remake of "Coupling"?
>>
>> They did that? I don't want to think about it.
>
> They did, and it was interesting, even if it was an utter failure as
> entertainment - because the US episodes were changed very little from
> their UK counterparts. But while the UK versions were generally quite
> funny (even for US viewers who saw them on BBC America or the like), the
> US ones fell flat.
Flatwise, it was like Pancakeville, USA.
Absolute lead balloons, from beginning to end.
> As I recall, it was hard to pin down precisely what was wrong with the
> US versions - I don't remember particularly bad acting or direction or
> anything. It was more a case that the scripts were written with
> conventions of UK television genres in mind, and those didn't match the
> generic expectations for US television genres.
I think that's about it. It may also be that the show (somehow due to
direction, [re-]writing, acting) was not doing full justice to the
characters -- they came over perhaps a bit flat and American-sitcom-y as
I recall. Tricky problem: maybe we wouldn't have accepted quirky and
strongly drawn characters as Americans if they were as quirky and
strongly drawn as in the British version.
Anyway, the British ensemble cast was a marvel, had great chemistry
together on screen, and is the sort of thing you don't really expect to
see twice with the same scripts. And we didn't.
--
Roland Hutchinson
He calls himself "the Garden State's leading violist da gamba,"
... comparable to being ruler of an exceptionally small duchy.
--Newark (NJ) Star Ledger ( http://tinyurl.com/RolandIsNJ )
Roland Hutchinson
> On Sat, 21 May 2011 19:08:34 +1000
> "Rod Speed" <rod.sp...@gmail.com> wrote:
>
>> Rod Speed wrote
>> > Ahem A Rivet's Shot wrote
>
>> >> My point is that while this is indeed difficult it is not as
>> >> difficult as making something that flies and runs at better than
>> >> 30mpg.
>>
>> > Thats just plain wrong. There are plenty of cars that do better than
>> > 30mpg buyable right now.
>>
>> I obvious meant
>>
>> Thats just plain wrong. There are plenty of planes that do better than
>> 30mpg buyable right now.
>
> I confess to considerable surprise, can you point me at examples ?
>
>> >> I *am * in Europe and we certainly have gone the route of *not*
>> >> flying.
>>
>> No you havent, there is more flying going on in europe than there has
>> ever been.
>
> I was obviously referring to flying in cars not airliners.
And the trains are pretty decent in most European countries. (Not
necessarily the English-speaking ones.)
Nick Spalding
on Sat, 21 May 2011 22:37:29 +0200:
> In article <ldret69fgcn8tgp50...@4ax.com>,
> Nick Spalding <spal...@iol.ie> wrote:
> >hanc...@bbs.cpcn.com wrote, in
> ><fd6a098b-df04-4c3c...@e13g2000vbo.googlegroups.com>
> > on Fri, 20 May 2011 19:18:28 -0700 (PDT):
> >
> >> On May 20, 7:27 pm, Quadibloc <jsav...@ecn.ab.ca> wrote:
> >>
> >> > Not really. There's a British company, Cable and Wireless, which owns
> >> > a few of them, that I've heard of...
> >>
> >> Gee, C&W dates way back to telegraph days. They used to own isolated
> >> islands (maybe still do) as repeater stations.
> >
> C&W is still going strong. Still handles oodles of traffic to
> every bit of the planet that once carried a red map colour.
> (That includes the Yankees, too.)
>
> >I don't think they owned many of them but they certainly leased space on
> >them. I mentioned a couple of them elsewhere in this thread. Most of
> >the C&W cables were inherited from the Eastern Telegraph Company and its
> >associated companies. At the time I worked for them there were a
> >considerable number of cables laid in the 1800s still in use.
>
> They have a huge outfit at Brean, out in Cornwall where lots of sea
> cables leave for other continents. They lease half of Ascencion Island;
> and significant bits of Cocos and other similar islands.
I think you may mean Treen. The actual cable landing is at Porthcurno.
I spent 1951 there when it was the training school for C&W. The old
cables are still there, the cable house on the beach is a tourist
attraction these days and the old relay station, moved into tunnels in
the valley side at the beginning of WWII, is a museum of the old cable
technology.
The tunnel entrances can be seen on GE at 50° 2.828'N 5° 39.299'W. The
building beside them is the pre-war station, empty when I was there.
Treen was the nearest place with a pub, about 1km away.
> Even Iceland. Iceland covers a big enough stretch to have a full repeater
> station in each end. So does Greenland. So the CANTAT route goes
> Scotland-Faroes-Iceland-Iceland-Greenland-Greenland-Labrador-Mainland,
> avoiding any need for a full repeater station in the sea.
>
> And providing Iceland and Greenland with excellent connectivity in the
> process.
>
> A similar one is planned Norway-Spitsbergen-Spitsbergen-Greenland-Baffin-
> (TBD islands in the far northern bits of Canada)-Alaska-Aleutes-Kamchatka-
> Japan, making the far east to europe route 40 milliseconds shorter.
>
>
> -- mrr
--
Nick Spalding
jmfbahciv
> On 5/21/2011 7:31 AM, jmfbahciv wrote:
>> Michael Wojcik wrote:
>>>
>>> Personally, I'd be satisfied with 6 fps if they were 6 full frames,
>>> with no dropped blocks, and if the damn audio didn't keep cutting out.
>>> (Stupid oversubscribing cable companies...) Dropped audio bugs me
>>> about a zillion times more than dropped video, since audio's usually
>>> far more important to the narrative, in the shows I watch.
>>>
>> Perhaps I won't buy cable if that happens. Over-the-air does that
>> all the time...at least with the few stations I can get. I still
>> can't get the digital channels I used to before the switch.
>> My mother can off-hours. Last month, reception is "no signal"
>> from 7:00-17:00. Can digital TV signals be [can't think of the
>> word now] interferred with?
>>
>
> It sure can. (Also can be too weak.) And the quality does not
> degrade gracefully, as with analog. It's a very short step from
> "perfect" to "nothing at all".
>
> FWIW, if you don't have a rooftop antenna (and perhaps a rotator, if
> the stations aren't all in the same direction), you might find that
> would help a lot.
My mother has that kind of antenna. The dropped signals which begin
at 7:00 just started two weeks ago. Before that, her reception was as
fine as one can get with the digital broadcasting. Is it possible to
speculate what might be causing the interference of her reception?
Where is the fucking FCC when you need it?
I remember DEC going to great expense, including building an anechoic
chamber, when the FCC rules declared that no hardware could interfere
with things such as TVs. Do those rules apply to the digital signals?
> Even here (in the middle of a sizeable metro area,
> so we're a lot closer to the stations than you are) set-top antennas
> don't work anywhere near as well for digital as they did for analog.
>
I use a set top. I was getting all the digital channels before the
switch. The day the switch happened, I stopped receiving Fox, ABC
NBC, and CBS's 3 digital channels. The only show I missed was
_The Big Bang_ ...and the 3 horse races.
/BAH
Peter Flass
snip .... US remake of "Coupling"]
>
> I think that's about it. It may also be that the show (somehow due to
> direction, [re-]writing, acting) was not doing full justice to the
> characters -- they came over perhaps a bit flat and American-sitcom-y as
> I recall. Tricky problem: maybe we wouldn't have accepted quirky and
> strongly drawn characters as Americans if they were as quirky and
> strongly drawn as in the British version.
It's an interesting question. Is this what we want, or is this what the
networks _think_ we want? I guess we're never going to get a chance to
find out. Producing a TV series is jut too expensive for the networks
to want to take many chances.
Andrew Swallow
on the US channels this behaviour may change.
Andrew Swallow
Dave Garland
> Dave Garland wrote:
>> FWIW, if you don't have a rooftop antenna (and perhaps a rotator, if
>> the stations aren't all in the same direction), you might find that
>> would help a lot.
>
> My mother has that kind of antenna. The dropped signals which begin
> at 7:00 just started two weeks ago. Before that, her reception was as
> fine as one can get with the digital broadcasting.
It would be instructive to know if her neighbors experience the same
dropped signals. If not, look close to home. If they do, then you
stop looking around the house for the problem and look further afield.
E.g., didn't the military have some high-power communications stuff
based in NoMi? Could they be running tests? Or a local ham radio
operator might be able to figure out what the problem was, many of
them are pretty knowledgable about finding sources of interference.
Is it possible to
> speculate what might be causing the interference of her reception?
Half the electronic gadgets we have are potential candidates, if
they're malfunctioning. Computers. And industrial equipment, motors
and fluorescent lights and stuff like that. But if it always happens
at exactly the same time, that's a big clue.
> Where is the fucking FCC when you need it?
Chasing down networks where people experience "wardrobe malfunctions"
or say naughty words.
> I remember DEC going to great expense, including building an anechoic
> chamber, when the FCC rules declared that no hardware could interfere
> with things such as TVs. Do those rules apply to the digital signals?
Not sure. Probably, but the onus is on you to find the source of
interference.
>
>
>> Even here (in the middle of a sizeable metro area,
>> so we're a lot closer to the stations than you are) set-top antennas
>> don't work anywhere near as well for digital as they did for analog.
>>
> I use a set top. I was getting all the digital channels before the
> switch. The day the switch happened, I stopped receiving Fox, ABC
> NBC, and CBS's 3 digital channels. The only show I missed was
> _The Big Bang_ ...and the 3 horse races.
When the switch happened, a lot of stations (even those who were
already broadcasting in digital) changed frequencies and power.
Channel number used to correlate to frequency, I don't think it does
any more.
Dave
Rod Speed
> jmfbahciv wrote
>> Dave Garland wrote
>>> FWIW, if you don't have a rooftop antenna (and perhaps a rotator, if the
>>> stations aren't all in the same direction), you might find that would help a lot.
>> My mother has that kind of antenna. The dropped signals which begin
>> at 7:00 just started two weeks ago. Before that, her reception was
>> as fine as one can get with the digital broadcasting.
> It would be instructive to know if her neighbors experience the same
> dropped signals. If not, look close to home. If they do, then you
> stop looking around the house for the problem and look further afield.
I dont believe it is interference, both because digital TV is very interference
robust, and because interference doesnt start and stop so regularly.
> E.g., didn't the military have some high-power communications
> stuff based in NoMi? Could they be running tests?
Test arent likely to be that regular either unless the story
on the purported regularity has got completely mangled.
And I cant see the military actually being stupid enough to
wipe out something as widely used at digital TV anyway.
> Or a local ham radio operator might be able to figure out what the problem was,
> many of them are pretty knowledgable about finding sources of interference.
I bet its not interference. Its much more likely to be something like those operations
are required to reduce power in those times for some regulatory reason etc.
The ham may well know that and can certainly check if thats whats
happening and would presumably be affected himself if its not very local.
>> Is it possible to> speculate what might be causing the interference of her reception?
> Half the electronic gadgets we have are potential candidates, if
> they're malfunctioning. Computers. And industrial equipment, motors
> and fluorescent lights and stuff like that. But if it always happens
> at exactly the same time, that's a big clue.
Digital TV is VERY immune to interference. Thats part of the point of it.
>> Where is the fucking FCC when you need it?
> Chasing down networks where people experience
> "wardrobe malfunctions" or say naughty words.
>> I remember DEC going to great expense, including building an anechoic
>> chamber, when the FCC rules declared that no hardware could interfere
>> with things such as TVs. Do those rules apply to the digital signals?
> Not sure. Probably, but the onus is on you to find the source of interference.
I dont believe it is interference.
Rod Speed
Its unlikely to be interference. Whats the location ?
Anne & Lynn Wheeler
Anne & Lynn Wheeler <ly...@garlic.com> writes:
> same ietf meeting there was presentation on number of bits outstanding
> in gbit coast-to-coast terrestrial fiber link was about the same as
> number of bits outstanding in T1 satellite link.
re:
http://www.garlic.com/~lynn/2011g.html#20 TELSTAR satellite experiment
http://www.garlic.com/~lynn/2011g.html#27 TELSTAR satellite experiment
round-trip satellite is almost 90,000 ... while coast-to-coast
terrestrial is around 7,000 ... making it a little over order of
magnitude. similar bit-in-transit product for t1 satellite would be
around twice ENET ... less than half T3, well less than FDDI or
gbit.
big congestion problem was burst of back-to-back packets at intermediate
and/or destination. windowing and slow-start only indirectly addressed
back-to-back packets. real-life multi-hop network would periodically
bunch returning ACKs resulting in burst of back-to-back packets being
transmitted ... exactly what was trying to be prevented.
changing the paradigm from window to rate-based ... would directly
address the back-to-back packet transmission issue.
this had been done in HSDT in the early to mid-80s ... misc. past
posts mentioning HSDT
http://www.garlic.com/~lynn/subnetwork.html#hsdt
then in the late 80s, I was on the XTP technical advisory board (despite
strong objections from the corporate communication group) and wrote it
up for XTP protocol. misc. past posts mentioning XTP (and/or trying
to get XTP standardized in ISO/ansi x3s3.3
http://www.garlic.com/~lynn/subnetwork.html#xtphsp
--
virtualization experience starting Jan1968, online at home since Mar1970
jmfbahciv
> On 5/22/2011 7:35 AM, jmfbahciv wrote:
>> Dave Garland wrote:
>
>>> FWIW, if you don't have a rooftop antenna (and perhaps a rotator, if
>>> the stations aren't all in the same direction), you might find that
>>> would help a lot.
>>
>> My mother has that kind of antenna. The dropped signals which begin
>> at 7:00 just started two weeks ago. Before that, her reception was as
>> fine as one can get with the digital broadcasting.
>
> It would be instructive to know if her neighbors experience the same
> dropped signals.
There are none.
> If not, look close to home. If they do, then you
> stop looking around the house for the problem and look further afield.
I don't think she started using anything "new".
> E.g., didn't the military have some high-power communications stuff
> based in NoMi? Could they be running tests? Or a local ham radio
> operator might be able to figure out what the problem was, many of
> them are pretty knowledgable about finding sources of interference.
>
> Is it possible to
>> speculate what might be causing the interference of her reception?
>
> Half the electronic gadgets we have are potential candidates,
I was afraid of that.
>if
> they're malfunctioning. Computers. And industrial equipment, motors
> and fluorescent lights and stuff like that. But if it always happens
> at exactly the same time, that's a big clue.
Right. 07:00 is when somebody starts working. I'm going to have to
collect more data from her before doing any more thinking about it.
>
>> Where is the fucking FCC when you need it?
>
> Chasing down networks where people experience "wardrobe malfunctions"
> or say naughty words.
Ah, non-useful work.
>
>> I remember DEC going to great expense, including building an anechoic
>> chamber, when the FCC rules declared that no hardware could interfere
>> with things such as TVs. Do those rules apply to the digital signals?
>
> Not sure. Probably, but the onus is on you to find the source of
> interference.
Actually, my thinking morphed back to real computing life and started
wondering about what kinds of work is involved to FCC-itize digital
signals, or if the regs even exist.
>>
>>
>>> Even here (in the middle of a sizeable metro area,
>>> so we're a lot closer to the stations than you are) set-top antennas
>>> don't work anywhere near as well for digital as they did for analog.
>>>
>> I use a set top. I was getting all the digital channels before the
>> switch. The day the switch happened, I stopped receiving Fox, ABC
>> NBC, and CBS's 3 digital channels. The only show I missed was
>> _The Big Bang_ ...and the 3 horse races.
>
> When the switch happened, a lot of stations (even those who were
> already broadcasting in digital) changed frequencies and power.
> Channel number used to correlate to frequency, I don't think it does
> any more.
I had thought that the experiments were broadcast at half-power
when the stations were shipping both types of signals. I had
assumed that, by turning off analog, they could supply full
power to the digital signal. One would also assume that the
frequencies of the digital signals didn't change from one day
to the next. Those are still uniquely assigned to stations...
aren't they?
/BAH
Roland Hutchinson
The more interesting question is how would we know what we want if the
networks didn't constantly tell us what to want.
Dave Garland
> I had thought that the experiments were broadcast at half-power
> when the stations were shipping both types of signals. I had
> assumed that, by turning off analog, they could supply full
> power to the digital signal. One would also assume that the
> frequencies of the digital signals didn't change from one day
> to the next. Those are still uniquely assigned to stations...
> aren't they?
Don't know the answer re power, but that might not be a safe
assumption. However, it's likely that any changes would have been in
effect long before your mom started experiencing the problem.
Frequencies may have changed on change-over day, but they should be
constant from day to day otherwise.
Dave
Patrick Scheible
> On Sun, 22 May 2011 08:42:55 -0400, Peter Flass wrote:
>
> > On 5/22/2011 1:55 AM, Roland Hutchinson wrote: snip .... US remake of
> > "Coupling"]
> >>
> >> I think that's about it. It may also be that the show (somehow due to
> >> direction, [re-]writing, acting) was not doing full justice to the
> >> characters -- they came over perhaps a bit flat and American-sitcom-y
> >> as I recall. Tricky problem: maybe we wouldn't have accepted quirky
> >> and strongly drawn characters as Americans if they were as quirky and
> >> strongly drawn as in the British version.
> >
> > It's an interesting question. Is this what we want, or is this what the
> > networks _think_ we want? I guess we're never going to get a chance to
> > find out. Producing a TV series is jut too expensive for the networks
> > to want to take many chances.
>
> The more interesting question is how would we know what we want if the
> networks didn't constantly tell us what to want.
The networks are only one source of advertising. I haven't watched
broadcast TV since, hm, about 2002, yet there are still some things I
want. Even things that aren't a fixed version of a thing I already
have.
-- Patrick
Roland Hutchinson
Yes, but I'm sure the networks would think that you don't want enough
things.