Lisa Hancock <hancock4@bbs.cpcn.com> wrote:
> 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?
Anthony Bellanga <anthonybellanga@withheld> responded:
> 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.
The "new emerging cable services" didn't emerge until satellite
distribution made them economically feasible. Before satellites came
along, cable television systems relied almost exclusively on broadcast
stations for their programming.
Given enough money, the cable industry could have built a microwave
network with sufficient capacity to distribute non-broadcast
cable-only programming nationally. But the industry never considered
it: the cost would have been astronomical. By the early 70s, the
industry had been around for 25 years, and there were far more cable
headends than broadcast stations in the country. A ground-based
microwave network for cable TV would have had to reach many more
end-points than the network AT&T was operating for the broadcast
networks. Headends in remote places like mountaintops or barrier
islands might never have been reached.
The first nationally-distributed satellite-delivered non-broadcast
programming service was Time Inc's HBO, launched in December 1975 on
Satcom 3R. Prior to its satellite launch, Time had been using
non-AT&T microwave to distribute HBO to its own cable systems in the
northeast. Time wanted to extend HBO's coverage nationwide, and
satellite was the only economically-feasible way to do it.
Once HBO broke the ice, other non-broadcast services soon followed.
By 1979, programming was available from Turner Communications Group
(WTCG, now TBS Superstation), Christian Broadcasting Network (CBN),
Southern Satellite Systems (Satellite Programming Network, or SPN),
USA Network, C-SPAN (sharing transponder time with USA), ESPN, and
Nickelodeon. A year later, Turner launched CNN, the first in a string
of non-broadcast services that now includes Cartoon Network, CNNSI,
CNNFN, Headline News, TCM, and TNT.
Of course, not all of these new services survived. CBN became ABC
Family; SPN morphed into CNBC. Others flashed across the horizon and
disappeared: Reuters "Newsview"; FNN (Financial News Network); TEC
(The Entertainment Channel); HTN (Home Theater Network); MSN (Modern
Satellite Network); Cinemerica.
But the basic financial model worked: operating a non-broadcast
satellite-delivered programming service proved to be a viable
business. These services now make up the bulk of the programming
offered by cable television systems on their basic and extended-basic
tiers.
Lisa continued:
> With satellites, is there a problem with transmission
> lag time?
Anthony continued:
> Radio/TV network broadcasting is different [from
> telephone conversations] in that a program usually
> originates from one point (or maybe a small number of
> locations) and is sent to "everyone" across the
> country...
Programming production studios sometimes have a trio of video monitors
sitting side-by-side:
- The first displays the program signal directly from
the studio.
- The second displays the downlink from the programmer's
own uplink, after a delay of about 0.24 seconds (one
round trip to/from a geostationary satellite).
- The third displays the downlink from the DirecTV or
Dish Network, after a delay of about 0.48 seconds (two
round trips).
It's fascinating to watch the same image signal jump from monitor to
monitor. But a home viewer would never be aware of it.
But two-way phone conversations make the round-trip delay obvious. I
often notice this on CNN when the studio anchor asks a question of a
field reporter who is using a videophone. After the anchor finishes
the question, we watch the reporter just standing there (trying not to
look stupid) for a half second before answering.
Neal McLain
Neal McLain (nmclain@annsgarden.com)