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Instead of sitting at our computer writing this comment in response to your editorial, "Where is the Grandma Phone?" (EDN, June 20, 1996, pg 11), I should be inputting my "valued inventory list" in preparation for our move to France (the packers arrive in less than one week). Thanks to "Grandma," a clipping of your article just arrived, and I think she's trying to tell me something.
Of course there should be a "Grandma Phone"!
Eight years ago, when I was seven months pregnant with our second child, my husband and I moved our family from Florida to Hong Kong. We did not, however, move without bringing our Panasonic WG-R2 Visual Telephone. It was my father who saw the importance of visual communication and its ability to keep our family in touch with each other.
Our visual phone made it possible to send immediate pictures of our new daughter to Grandma and Grandpa; our son was able to send photos of his latest Lego creations; we were able to send people immediate views of our new flat; and I even used it to send photos of my new and drastic haircut. The visual phone was wonderful.
Granted, we did have to get past the difference in electrical current and locate various adapters, but once it was up and running, the visual telephone worked beautifully. We also had to decide if we wanted to talk or send a visual, which were sent via the phone line and took approximately six seconds. This wasn't too bad, though it did add a bit of a lag in the conversation. My folks even hooked up their phone to the television and VCR and were able to record the visuals and conversation for later viewing.
A year ago we left Grandma and Grandpa in Minneapolis and moved to the Boston area. Telephones, faxes and e-mail have sufficed thus far, but we are now preparing to move to Paris. The Panasonic WG-R2, even though it is in black and white and is very slow, is being packed and shipped to France to be put back to use.
It would be great if there was a color version of this wonderful little box, one that operated audio and visual simultaneously and, of course, was priced for the consumer.
I'm with you—waiting for the Grandma Phone.
Nancy Cash
My three beautiful grandchildren live with my son in Oklahoma City. I live in Buffalo, NY. I see my grandchildren twice a year…if I'm lucky. I've tried all sorts of speakerphones that have led to more disappointment. Please add "Grandpa Phone" to your list of names for it. I am with your mother…so where is it already?!
I have talked to quite a few other folks who would jump at a $500 video phone. I have asked, queried, and suggested to AT&T, Sony, Panasonic, JVC, and any other representative I could get to listen to me. No one has responded to me yet.
You are also right about the quality… I would take a frame a second. I would like color and would even use my own TV set as the monitor if it will keep down the cost. I could even live with using my camcorder as the camera if that would encourage sales. So where is it already?
Bill Parker
Electrical Engineering Group Leader
McKenica
Buffalo, NY
I have been involved neck-deep in the design and engineering of sophisticated video communications for more than eight years. My specialty has been blending the worlds of AV with computers and telephones in, shall we say, somewhat sophisticated and occasionally unusual applications for training and communications for various agencies of the government that fall within the spectrum of federal law enforcement. It has been great and I have enjoyed the challenge of some of the complexities.
Despite my level of expertise in this area, and despite the fact that I have video conferencing integrated in my home computer/television/DSS system for the purpose of meeting and conducting training from my living room instead of the office downtown, I have felt that the big gap in video-communications technology was that there was not a telephone that also had video compatibility. You hit it exactly right in your editorial. Not everyone is an Internet/PC/digital audio/telephone freak who wants the ultimate engine of communication and dreams of it being housed inside the face of their wristwatch! Taken from another point of view, Geoffrey Moore said it well when he noted that "most everyday people thoroughly enjoy and use pocket knives, microwave ovens, bicycles, and telephones, but they don't necessarily want them combined into a single device."
The good news is that I recently found the "Grandma Phone" of videoconferencing. It looks like an ordinary phone. It operates like an ordinary phone. It doesn't offer the end user an unfamiliar or graphically cryptic interface. In fact, with the exception of the slimline LCD display, you would have no idea that this wasn't just another modern telephone. The unit I am talking about is the BT Visual Systems Portrait VC9000 Video Telephone. Quite frankly, this is one of the nicest pieces of videoconferencing hardware I have ever seen or used. It has complete interoperability with other systems that are H.320 compliant (I have called systems from CLI, VTel, PictureTel, Intel, ERIS, and BT, and NEC desktop and big-room systems with absolutely no problems). The unit can operate with the normal handset or hands-free, and the audio quality remains high in either mode. There is no noticeable drop-off in clarity or in volume when using the unit in hands-free mode. The unit delivers clean images at 12 to 15 frames per sec, and has the least amount of delay of any product I have worked with. But the real beauty of the unit is that opening the box, assembling the unit, connecting to the network, and dialing and connecting a video call took me less than 90 sec!
I realize this all sounds too good to be true, but I can say that it is true and that you were right on with your editorial. It's about time that a) Someone with profile and authority came forward to define this issue with absolute clarity (that would be you and Grandma) and b) Someone came out with a product that meets the "Grandma Criteria Coefficient Curve" (that would be BT Visual Systems).
Thank you for a great editorial. Your mother must be proud.
Scott Sharer
Savannah, GA
PS. In case this letter sounds like it has a vested interest, I am a design engineer and consultant only. Even I had to pay full price for my BT VC9000.
Re: "Fear and Loading in Las Vegas" (EDN, July 18, 1996, pg 11): You are overstating the problem considerably when you say "Everything I knew and everything you know about ASIC design has just crumbled to dust."
I don't think so.
The problem you describe is the so-called short-path problem, which certainly is well known, especially among GaAs designers. If you have a chain of two (or more) fast flip-flops, then you have a problem meeting hold times. This is worse when the flops are on different clock tree branches, but also applies if they are on the same clock, if the path is real short.
The case you gave is an extreme example of this, a flip-flop connected back to itself. Usually, however, you would need some scan control on the flip-flop, so a multiplexer would be inserted into the path. If this is still too fast, a buffer would be inserted. Existing static timing analysis tools would find these hold-time problems.
Gary Burke
via the Internet
In your editorial, you state that too much delay in sub-0.5-mm processes violates flip-flop hold times. This doesn't make any sense; the only way that too much delay could cause a hold-time violation is if the delay was long enough to cause the input not to change until the next clock cycle. It seems much more likely that too little delay in the circuit (especially in the scenario described where /Q is looped back to the input) is what really causes the hold-time violation. In other words, the circuit is so speedy that /Q changes before the minimum hold time of the circuit. This seems like an easy problem to solve in software if the EDA vendors are aware of it. All that needs to be done is to check for a minimum delay between synchronous flip-flops. A minimum feedback/feedforward (to a synchronous flip-flop such as a shift register) path rule is all that is needed. This is probably new and not yet supported as you have stated. You imply that clock rate would cause this problem to be more evident, but clock rate should not affect this problem (the too short feedback path would exist no matter what the clock rate), although clock edge speed might. I hope you will print a correction so that the rest of your readers are not asking their EDA vendors about the wrong problem.
Warren Watts
via the Internet
I find EDN to generally have excellent articles, but in this case I was so annoyed by the lack of depth in the article, "When the going gets tough…products for harsh environments'' (August 15, 1996, pg 53), that I felt compelled to write this letter.
I have worked in the down hole oil- field industry for seven years, which provides real insight into a "harsh'' environment. I found this article little more than an advertising blurb for products which, for the most part, don't even meet military specs.
If you want to talk about harsh environment, get real. Look at 150°C+ operating temperatures and 100G+ continuous shock and vibration specs. Some vendors are working in the field, Honeywell being a notable example. The applications are onboard jet and combustion engines, rocket motors, helicopters, oil fields, etc.
Daniel Lerner
Schlumberger-Anadrill
Slim MWD Engineering
Sugar Land, TX
EDN apologizes for the inaccuracies.
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