linc@tongue1.berkeley.edu (Linc Madison) (01/17/91)
I, like most of the country, spent much of the last twelve hours glued to my television set. My local NBC affiliate, KRON-TV, is also affiliated with CNN, so they were switching back and forth between the two. I noticed several differences in the coverage from Baghdad. Of course, no video was going out live from Baghdad, but these two networks were giving audio coverage. NBC's audio was clearly just a plain telephone connection, with all the bandwidth limitations that implies. CNN's audio, though, sounded much clearer. Further, at one point NBC lost the phone connection and didn't regain it for some time, but CNN maintained its hookup and even piped it to NBC (at a cost that Tom Brokaw had to effusively speak of how wonderful CNN is). Brokaw, in fact, asked CNN how they did it, and the reporter was quite secretive. So how did they do it? My initial guess was some sort of multiplexed multiple phone lines, but it seems that all regular phone lines from Baghdad were disrupted. Any ideas? Of course, I hope that this experiment in telecommunications in crisis situations is as short-lived as possible. Linc Madison = linc@tongue1.berkeley.edu P.S. Plea to other contributors: *please* include your e-mail address in your signature line. My system doesn't reply well to moderated groups.
jet@karazm.math.uh.edu ("J. Eric Townsend") (01/19/91)
In article <16147@accuvax.nwu.edu> linc@tongue1.berkeley.edu (Linc Madison) writes: >Brokaw, in fact, asked CNN how they did it, >and the reporter was quite secretive. >So how did they do it? My initial guess was some sort of multiplexed >multiple phone lines, but it seems that all regular phone lines from >Baghdad were disrupted. Any ideas? Something called a "four-line" or "four-wire", according to CNN. It seems that only CNN was (pre-war) allowed to "lease" one of these from the Iraqi government. Best I can tell, they used it to transmit to Jordan, at which point they were patched into a phone network. I'm not a telephony guru, so I dunno... J. Eric Townsend Internet: jet@uh.edu Bitnet: jet@UHOU Systems Mangler - UH Dept. of Mathematics - (713) 749-2120 [Moderator's Note: I believe the link outbound from Jordan was via satellite to the United States, then into a wire-line once it got here. Hopefully we can have a couple of detailed responses on this over the weekend. PAT]
bsherman@mthvax.cs.miami.edu (Bob Sherman) (01/19/91)
In <16147@accuvax.nwu.edu> linc@tongue1.berkeley.edu (Linc Madison) writes: [ stuff deleted] >NBC's audio was clearly just a plain telephone connection, with all >the bandwidth limitations that implies. CNN's audio, though, sounded >much clearer. Further, at one point NBC lost the phone connection and >didn't regain it for some time, but CNN maintained its hookup and even >piped it to NBC (at a cost that Tom Brokaw had to effusively speak of >how wonderful CNN is). Brokaw, in fact, asked CNN how they did it, >and the reporter was quite secretive. Bernie Shaw is no dummy. The CNN boys outdid the competition, and he was not going to tell them at this time, although he did promise to tell Brokaw over dinner sometime after he returns to the States. >So how did they do it? My initial guess was some sort of multiplexed >multiple phone lines, but it seems that all regular phone lines from >Baghdad were disrupted. Any ideas? Yes, without giving away their trade secrets before they wish to make them public, let me just say it was a device that is mainly used on large ocean vessels, oil rig towers in the middle of nowhere, etc and was rigged to operate off of either commercial voltage with a drop down device or battery power in the event that commercial power failed (which it did.) I am glad that I do not have to pay their bill, which costs several dollars per minute ... for all of the hours they were using it. They also had with them, a portable electric generator which they purchased in the Washington DC area before they went over there, along with tons of Tuna fish, etc. bsherman@mthvax.cs.miami.edu MCI MAIL:BSHERMAN
clear@cavebbs.gen.nz (01/21/91)
In article <16147@accuvax.nwu.edu> linc@tongue1.berkeley.edu writes: >how wonderful CNN is). Brokaw, in fact, asked CNN how they did it, >and the reporter was quite secretive. >So how did they do it? My initial guess was some sort of multiplexed >multiple phone lines, but it seems that all regular phone lines from >Baghdad were disrupted. Any ideas? VSAT, or Very Small Aperture Terminal. Typically a 1.8m satellite dish, with associated electronics will sit happily on a single-axle trailer and be towed behind a car. They are used worldwide, with the highest concentration in Alaska, Yukon and North-West Territories. They are used by mining, timber, oil and exploration teams for semi-portable comms links between the camps and the outside world. Basically, the VSAT system provides one or more digital voice channels compressed and sent via FM to the satellite and back to any other earth station within the satellite's shadow. A typical scenario has a camp PABX, modem and fax all running into the VSAT terminal. Because the system does not interface with the PSTN until it leaves the earth station, miners in the Arctic can get local dialtone for Vancouver, Calgary, Seattle and anywhere else there is a compatible receiving system. Hence crystal clear voice communications when landlines are either nonexistent or very unreliable. I'd bet bucks that CNN used a VSAT to bypass the entire Iraqi PSTN and was getting Saudi or Israeli dialtone - maybe even further afield. One manufacturer / service provider is Infosat Telecommunications of Burnaby, Vancouver, BC. They are a subsidiary of Nexus and have supplied VSATs to a number of companies operating in the wilderness. Disclaimer: only association with Infosat was meeting with their people and looking over the factory as part of the Intercomm '90 conference. The technology impressed the hell out of me! Charlie "The Bear" Lear | clear@cavebbs.gen.nz | Kawasaki Z750GT DoD#0221 The Cave MegaBBS +64 4 643429 V32 | PO Box 2009, Wellington, New Zealand
piet@cs.ruu.nl (Piet van Oostrum) (01/21/91)
This weekend I saw an interesting note in a newspaper about telecommunications used by some journalists. I don't know if it applies to CNN but it surely was interesting. They have two briefcases, one containing a portable satellite antenna (lloks like an upside down umbrella), and one with a computer. They rent a hotelroom with a window on the south side (or north on the southern hemisphere), and when they want to make a phone call, they direct the antenna to the satellite, type in their user number and password, and make the phone call. No dependency on local telephone companies, state censors, etc. The satellite used is Inmarsat (if I remember the name correctly), that is mainly used for maritime telephone traffic. They must have arranged a subscription on the satellite, of course. Piet* van Oostrum, Dept of Computer Science, Utrecht University, Padualaan 14, P.O. Box 80.089, 3508 TB Utrecht, The Netherlands. Telephone: +31 30 531806 Uucp: uunet!mcsun!ruuinf!piet Telefax: +31 30 513791 Internet: iet@cs.ruu.nl (*`Pete')