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Ladies Night Day


Monday, January 03, 2005

Half Duplex Mode

According to Webopedia, 'Full Duplex Mode' is a useful phrase that describes the simultaneous transfer of data in two directions.

An example of something that operates only in 'Half Duplex Mode' would be a typical 'walkie talkie'.  You push the button to transmit, and your voice is broadcast far and wide.  Release the transmit button, and you can listen to someone else's transmission.  But because it is only a 'Half Duplex' system, you cannot send and receive information at the same time.

So far so good?

Telephones, on the other hand, were designed to operate in 'Full Duplex Mode'.  The theory being that you are supposed to be able to talk and listen simultaneously... providing a close approximation of having a live, in-person conversation.

That's the theory anyway.

So why is it that nearly everywhere I look these days I see people (OK, it's mostly men) holding their cell phones directly in front of their mouths (with the earpiece nowhere near their ear), carrying on an uninterrupted monologue?  Doesn't this sort of defeat the magic of the 'Full Duplex' feature?

I mean, in theory I understand what these Neanderthals are doing.  They are using their phones as if they were 'walkie talkies'... holding down an imaginary transmit button until they are good and ready to hear what the other person has to say. Then (and only then) do they hold the phone against their ear and allow the other person to join the conversation.  However, the moment the cretin decides he wants to interrupt, the phone moves away from his ear and takes up its position directly in front of his mouth!

It's really an amazing thing to watch in action, and I know I'm not doing it justice here... but I need to ask a couple of questions:

Has anyone else noticed this 'Half Duplex' behavior? 

Also, Is this phenomenon only an Israeli thing???


Posted by David Bogner on January 3, 2005 | Permalink


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With us older married guys it is reversed. We listen and then maybe re are allowed to respnd

Posted by: dave | Jan 3, 2005 6:51:05 PM

yup...here too.
sometimes I just wanna toss mine out the window, just so I am not part of this whole phenomemon. (I do so dislike being part of a phenomemon)

Posted by: lisa | Jan 3, 2005 7:20:34 PM

Oy! Are you including MY David in that "us older married guys"?! We operate in full-duplex-mode, thank-you-very-much....

Posted by: zahava | Jan 3, 2005 7:27:59 PM

Maybe they all have that push-to-talk feature a la Nextel?

Posted by: Geoff | Jan 3, 2005 7:35:48 PM

I see that everywhere go. People don't want to listen until they are good and ready to do so.

Posted by: Jack | Jan 3, 2005 7:43:54 PM

Typically Israeli [Middle Eastern]. Okay, at least not observed around here but only when in Israel. Here, teenagers and 'important' people preferred ear knobs to give this bodyguard-intelligence-CIA-FBI-MI5-mehavebrainsgruntgrunt presentation. Bluetooth is quite hip, too. You get my point - I suppose it just serves some to appear really, really important.

Posted by: mademoiselle a. | Jan 3, 2005 8:22:20 PM

Dave... hold on... [muffled talking in the background], um yeah, I agree 100% with what Zahava said.

Lisa... Don't throw yours away... that will skew the statistics in their favor! :-)

Zahava... Yes dear.

Geoff... If that were the case I would be able to hear the other half of the conversation when I'm standing near them... but nice try. (By the way... welcome back... long time no 'see')

Jack... oh, so your hypothesis is that this behavior is not limited to phones? :-)

Mademoiselle a. ... Hey, I have a bluetooth earpiece and I don't indulge in that kind of behavior! And for the record I don't use it to look important (it actually looks a little dorky), but rather so I don't have the dangling wire between the phone and my ear.

Posted by: David | Jan 3, 2005 9:00:36 PM

I've actually never noticed it, but will keep an eye out for it. Are you positive they're talking to someone and not using their phone to swat at bees?

Posted by: Doctor Bean | Jan 3, 2005 9:28:37 PM

Doctor Bean... Quite sure, but now that you mention it they could have been taking a swing at some smug physician. :-)

Posted by: David | Jan 3, 2005 10:21:53 PM

Jack... oh, so your hypothesis is that this behavior is not limited to phones? :-)

Correct. I posted a dispatch from Danny Gordis that covers this, at least somewhat tangentially.

Posted by: Jack | Jan 4, 2005 1:28:07 AM

what's a cell phone?

Posted by: shabtai | Jan 4, 2005 1:59:49 AM


You SOOOOOOO look like you're suffering, too!

Posted by: zahava | Jan 4, 2005 10:58:27 AM


Posted by: SHIMMY | Jan 4, 2005 11:07:32 PM

Did anybody notice that this half duplex mode thing seems to apply to weblogs and comments too?

Posted by: Mark W. | Jan 6, 2005 8:19:05 PM

Not just an Isreali thing, I fear. This one of my biggest pet peeves, so much so I'd written a blog entry about it. In L.A. it seems to be prevalent among young men and women trying to appear cool. IMNSHO, they fail miserably. It's all I can do not to snatch the offending gizmo and throw it out the bus window.

Yes, I have to hear this BS on freaking mass transit. Damn idiots.

Posted by: Carol | Jan 7, 2005 6:16:43 AM

Hypothesis #1: They're afraid of radiation and don't want to hold it to their heads, where what's left of their brains could get fried.

Hypothesis #2: It's a camera phone, and they don't want to broadcast a picture of their inner ears.

Posted by: Zman Biur | Jan 10, 2005 4:02:31 PM

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