PAT, in order to deter $pam, please do NOT display my email address,
neither in the "from" line, nor in the "reply to" line.
Lisa Hancock wrote:
> Years ago, the Bell System carried network broadcast transmissions
> from first radio and then television. After WW II one of the
> functions of the new coaxial cable and microwave systems was capacity
> to carry TV signals.
> With satellites and competing companies that own their own fibre
> networks, does AT&T still carry broadcast transmissions today? If
> not, when did the transition start? Was this a blow to AT&T
> revenues?
Today, MOST all "long haul" and/or point-to-multi-point (network)
radio and TV is distributed by satellite. But remember that AT&T also
owns or is part-owner of several satellites as well.
"Short haul" (within the same city) distribution, such as "remotes"
seem to be handled half-and-half by the local telco (sometimes even on
a "dial-up" 3-Khz bandwidth basis! but also on a permanent or
temporary "leased line" basis too) as well as by private microwave
equipment owned by the TV or radio station, under FCC license for such
microwave too.
If a local radio or TV station is doing "remotes" on their own from
distant locations (Hurricanes, Iraq, etc), they would more than likely
use satellite equipment.
The first use of satellites for radio/TV pick-ups or distribution
first began in the 1960s when such satellites were new, novel
services, mostly for special events, such as Olympics, Coronations,
Space Shots, etc.
In the mid-1970s, the major radio networks (CBS, NBC, Mutual, ABC, and
even APRadio, UPI Audio, and even the less important radio services)
began to use RCA and Western Union domestic satellites for remote
pickups of sporting events outside of the usual program centers of New
York or Washington, as well as for sending "time-zone-delayed" feeds
to Chicago, Los Angeles, San Francisco (and the major radio networks
usually owned stations in all of the above mentioned major cities as
well), when the program was picked up in Chicago, L.A., or Frisco, it
then was distributed by Bell System landlines throughout the Central,
Mountain and Pacific time zones, sometimes with different programming
in different time-zones, delayed one, two or three hours.
When full landline distribution was in effect for both network radio
and network TV, Chicago would usually be the first point in the
Central Time Zone on a program fed out of New York or Washington
DC. And depending on how the network chose to have AT&T wire-up their
network, either Hollywood or San Francisco would be the first point in
the Mountain Time Zone for a program fed from the East or
Midwest. Chicago, and likewise Hollywood or Frisco, would tape,
transcribe (on wax disc), or "kinescope" the TV or radio program as
fed from the east, for playback one, two, or three hours later,
throughout the remainder of the network.
But with the use of RCA Satcom or WU Westar satellites, all program
delaying could be controlled directly out of New York or Washington
DC.
In the later 1970s, Mutual (which was radio only), NPR, APRadio, and
UPI Audio, and some other "minor" radio and TV networks (and I think
PBS-TV as well) decided to begin converting over to 100% satellite
distribution. In the "long run", use of RCA or Western Union with
satellites would be "cheaper" than using long haul AT&T lines. Of
course, there still might be the use of the local Bell or
"independent" telco on the distant local end, especially if the radio
or TV station couldn't place their dish in the same location as their
studios. Local telco loops would be needed to "backhaul" the program
from where the dish were located, back to the studio.
Also in the later 1970s, emerging national-in-scope Cable-TV services
such as HBO, CSPAN, CBN, CNN, etc. chose to distribute via satellite
directly to local cable franchise operation centers rather than use
Bell System facilities. I also don't know if Bell had enough landline
VIDEO capacity using the technology of the time for all of the new
emerging cable services, on a NATIONAL basis. Afterall, AT&T had
mostly been doing the distribution for ONLY three or four major
national TV networks for some 25+ years by the late 1970s -- CBS-TV,
NBC-TV, ABC-TV, NET/PBS, and the original (early 1950s) DuMont Network
which I understand was re-worked (as far as AT&T circuits were
concerned) into the "ad-hoc" Hughes Television Network of the
1960s/70s.
The three radio networks which also had associated TV networks -- CBS
Radio, NBC Radio, ABC Radio, continued to use satellites only for
backhaul of sports and specials which didn't originate in New York or
Washington DC, and also for "trunking" Central and Pacific programming
to Chicago and Hollywood or Frisco into the 1980s.
And while CBS-TV, NBC-TV, and ABC-TV also were using RCA and Western
Union satellites for the same purposes into the early 1980s, it wasn't
until 1982 or 1983 when the "big three" for *BOTH* their radio and
television networks, decided to migrate over 100% to satellite. On the
RADIO side, CBS, NBC, ABC all chose to go to a "proprietary" *DIGITAL*
system, all integrated so that an affiliate which was going to carry
programming and services from multiple providers could have a single
full-service set of equipment.
CBS Radio, NBC Radio, ABC Radio, and a one-time RKO Radio Network, all
chose to use "DAT" (Digital Audio Terminal) Technology from Scientific
Atlanta and distribution from RCA Americom's SATCOM.
(Mutual, PBS, NPR, APRadio and UPI Audio all went with Western Union
Westar in the late 1970s/early 1980s).
I don't know if CBS-TV and ABC-TV went with RCA, WU or someone else,
but in addition to CBS Radio and ABC Radio along with NBC Radio going
with RCA, so did NBC-TV. Afterall, RCA owned the National Broadcasting
Company.
Later in the 1980s, when General Electric purchased RCA and NBC, the
communication satellite division was renamed GE American
Communications.
Today, the players, movers-and-shakers, etc. have changed a bit in
name or owners, as media and technical entities have merged and
consolidated, but there's no turning back from the use of satellite
for long-haul national/network radio and TV.
Also, note that the remaining radio and TV networks, the "Big three",
made their announcement to migrate to 100% satellite around 1982 or
1983, for full use by 1984 and 1985.
Remember what else happened 20 years ago, on 1/1/84 -- this was the
official beginning of divestiture, the break-up of the Bell System,
where AT&T had to spin-off all its BOCs.
The "big-three" knew that RCA Satcom was relatively stable, but were
probably worried about what the new world of post-divestiture would
bring!
> Likewise, who actually carries long distance telephone calls? I use
> Verizon, do they own their wholly own long distance network
> capability of reaching any US central office? What medium is
> typically used -- ground coax, microwave tower, satellite, fibre.
> Or do all the other carriers simply contract in bulk with the
> established AT&T, Sprint, and MCI?
The "big three" of interexchange are AT&T, MCI, Sprint. But there are
many others out there with regional or national full networks,
including Qwest (the Long Distance side though), Global Crossing,
Vartech, and others. I think that Verizon as well has established
somewhat of a long distance network as well.
Of course, ALL of the common carriers do buy and route traffic over
each other depending on the circumstances.
> With satellites, is there a problem with transmission lag time?
YES!
In the 1970s, when AT&T (Bell) announced and even began to utilize,
Comstar (owned jointly by AT&T and GTE) satellites for long-haul toll
traffic trunking, there was major concern by many large business
customers. Two way voice telephone conversation with such a delay/lag
for the uplink and downlink to a small radio device some 23,000 miles
over the equator was indeed a concern, especially if a corporate
customer was conducting a teleconference! But it was a MAJOR worry for
two-way data transmission.
Radio/TV network broadcasting is different in that a program usually
originates from one point (or maybe a small number of locations) and
is sent to "everyone" across the country. But a two-way telephone (or
data) or full participating mulit-party teleconference needs to be as
"realtime" as possible!
AT&T did establish means for "forced" landline distribution of
switched "telephone" connections, to "avoid" satellites, for large
business customers. There were special routing codes to be used if the
call were really a data call, or a conference, etc.
Also, for telephone calls originating or terminating outside of the
mainland US or Canada, AT&T had to introduce special routing
instructions so that no domestic satellite circuit would be involved,
since the connection to the overseas location (including the
Caribbean, Alaska, Hawaii, and even "far-northern Arctic" Canada)
might involve an international satellite hop! Since one satellite
"hop" involves awkward delays, imagine what two or even three
satellite hops would be like!
There are going to be times when more than one satellite hop,
sometimes even as many as three, are going to be unavoidable, but
those are quite RARE. But where possible, AT&T's policy was to keep
the number of satellite hops when introduced into a 2-way switched
telephone call, to ONE and ONLY one.
> In 1970 AT&T descriptions, long distance routing had a triangle
> design. That is, most calls were sent to a toll center for
> subsequent routing. However, local exchanges had their own links to
> some nearby exchanges. For example, New York City to Newark NJ is
> "long distance" since it crosses states and LATA boundaries, but is
> physically so close calls be carried over plain copper interoffice
> trunks. Are such close LD calls still sent that way? It would seem
> strange to bounce 10 mile call off of a satellite.
Because of the complaints about satellite hops on most domestic (and
even many international calls), and also because of the falling prices
and proliferation of land-based and undersea fiber optic, as well as
digital microwave, about the only times you might encounter a
satellite hop within the North American network on a switched 2-way
(voice) telephone call is if one of the parties is in a remote Arctic
location, such as in remote parts of Alaska, or way up in northern
Canada outside of the landline network. There *ARE* landlines in
Alaska and also northern Canada's territories (Yukon, Northwest
Territories, Nunavut), but the more remote parts of the Arctic parts
of North America only interface with "down south" by satellite. Some
Pacific Ocean and Caribbean points of the North American network might
also still regularly use satellite to connect with each other or the
mainland, but telephone calls within a particular location will still
be landline, whether copper, fiber, microwave, etc.
Anthony Bellanga
Anthony Bellanga (anthonybellanga@withheld)