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The Telecom Digest for May 30, 2010
Volume 29 : Issue 146 : "text" Format
Messages in this Issue:
Re: IEEE article on GSM interference affecting GPS landing systems (tlvp)
Re: White Pages fading out? (Robert Bonomi)
Re: White Pages fading out? (Wesrock)
Re: Best way to get cellular/SMS/MMS from UK to USA? (Joseph Singer)
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Date: Sat, 29 May 2010 02:56:08 -0400
From: tlvp <tPlOvUBpErLeLsEs@hotmail.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: IEEE article on GSM interference affecting GPS landing systems
Message-ID: <htqdq9$fev$1@news.eternal-september.org>
Rob Warnock wrote:
> Michael D. Sullivan <mds@camsul.com> wrote:
> +---------------
> | AT&T uses GSM, which in turn employs TDMA transmissions. These switch
> | your phone's transmitter on and off about 1000 times per second when
> | the handset is communicating with a base station (yes, even when you
> | aren't using it, the handset periodically checks in). The result is
> | that a 1 kHz square wave is emitted. This can be induced into nearby
> | unshielded electronics and heard as an audio buzzing sound. This
> | often happens when a TDMA phone is next to a speakerphone, amplified
> | computer speaker, etc. This emission is very low level, so the phone
> | needs to be very close to the audio device.
> +---------------
>
> The basic GSM TMDA frame rate[1] is ~217 Hz, not 1000 Hz. A "full-rate"
> voice call is allocated only one slot per frame, so the duty cycle of
> the R.F. transmitter is only 1/8; a "half-rate" call [common with recent
> handsets with better codecs] uses only one slot every other frame, so it
> will appear to sound at ~108 Hz, rather than at 217 Hz. In either case,
> this makes the interference sound very rough -- more a "burp" (like a
> chain gun) than a "whistle".
>
> Other than that, most of what you say is correct. All it takes is just
> a bit of nonlinearity in nearby electronics to demodulate the R.F. and
> produce the 217 Hz (or 108 Hz) buzz.
>
>
> -Rob
>
> [1] 8 slots of 577 us or 4.615 ms per frame, thus 216.7 frame/s.
>
> -----
> Rob Warnock <rpw3@rpw3.org>
> 627 26th Avenue <URL:http://rpw3.org/>
> San Mateo, CA 94403 (650)572-2607
Just back from Poland, with two GSM phones always at the ready,
in an apartment with a cheap clock radio, and some observations:
Know how you pronounce the Polish musician Paderewski? -- pa de REF (etc.)?
Every time one of our phones was being sent an SMS (and lots of times between)
that cheap clock radio spewed out a buzzy "REF, pa de REF, pa de REF, ... ".
Perhaps a dozen iterations, before coming to a halt. 217 Hz buzz? Quite possibly.
And about two "pa de REF"s per second.
Cheers, -- tlvp
Date: Sat, 29 May 2010 15:24:51 -0500
From: bonomi@host122.r-bonomi.com (Robert Bonomi)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: White Pages fading out?
Message-ID: <EfqdndubBK2O5ZzRnZ2dnUVZ_tOdnZ2d@posted.nuvoxcommunications>
In article <771751a1-61db-4dfd-ad66-234357434022@b21g2000vbh.googlegroups.com>,
Jeff or Lisa <hancock4@bbs.cpcn.com> wrote:
>On May 27, 2:03 pm, bon...@host122.r-bonomi.com (Robert Bonomi) wrote:
>
>
>> The fact remains that the U.S. Supreme Court =settled= the issue in
>> "Feist V. Rural Telephone", 499 U.S. 340 (1991).
>>
>> Raw 'information' is not copyrightable; but "compilations" are.
>>
>> The SupCt held that the ordering of the data by a 'natural' scheme,
>> such as 'alphabetical' order did NOT meet the creativity standard
>> required for copyright to attach.
>
>When does 'raw information' become a "compilation"?
Never.
In a compilation of facts only the creative effort in making -that-
compilation ITSELF is protected by copyright. The underlying information
contained in the compilation is -not- so protected.
<snip remaining irrelevancies>
Date: Thu, 27 May 2010 10:02:58 EDT
From: Wesrock@aol.com
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: White Pages fading out?
Message-ID: <a3dd4.ca3c1d3.392fd592@aol.com>
In a message dated 5/27/2010 8:04:05 AM Central Daylight Time,
ahk@chinet.com writes:
> John Levine is speaking of a decades old US Supreme Court ruling,
> whose name escapes me right now. Cannot copyright an alphabetical list
> of names of residences or businesses. Categorized listings, however,
> are copyrightable, because assigning subject heading classifications
> is actual creative work.
> I've seen those copyright notices too. I have no idea what they are
> pulling.
The case involved a rural telephone company that served Gove, Kansas,
and some other counties in north central Kansas which successfully
prevailed in a suit against it for using allegedly copyrighted
listings published by one of the major companies, either GTE or
Southwestern Bell, if I remember correctly.
Wes Leatherock
wesrock@aol.com
wleathus@yahoo.com
Date: Sat, 29 May 2010 13:27:44 -0700 (PDT)
From: Joseph Singer <joeofseattle@yahoo.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Best way to get cellular/SMS/MMS from UK to USA?
Message-ID: <91381.79619.qm@web52707.mail.re2.yahoo.com>
Thu, 27 May 2010 17:23:54 -0500 "Gordon S. Hlavenka" writes:
> ... my niece will be spending about a month in England and Ireland
> this summer, possibly with day trips to neighboring countries.
> Her US carrier is Verizon, so no GSM capability on her phone. My
> off-the-cuff suggestion was to wait until she arrives across the pond
> and then get a cheap prepaid phone at Tesco or somesuch. The rates to
> the US would probably be pretty good and by going prepaid she'd avoid
> ugly billing surprises. I'd like to give a more specific
> recommendation if I can.
> In a perfect world, she'd primarily send and receive text messages,
> send a few photos, and occasionally make a voice call. Can this be
> done on the relatively-cheap?
Go into a mobile phone retailer such as CarPhone Warehouse and she'll
have the choice of several carriers and different "pay as you go"
mobile phones. They have different tariffs so go with the one that
has the best rates for calls and texts to the USA.
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End of The Telecom Digest (4 messages)
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