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Re: Digest Number 150

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  • Beehappy120@xxx.xxx
    In a message dated 11/1/99 1:31:24 AM Pacific Standard Time, coldwarcomms@onelist.com writes:
    Message 1 of 7 , Nov 1, 1999
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      In a message dated 11/1/99 1:31:24 AM Pacific Standard Time,
      coldwarcomms@onelist.com writes:

      << You can't listen to telephone calls transmitted via microwaves
      using a scanner or cellphone. >>
      I'm glad you pulled us up on this . Another apparent Urban Legend de-bunked.
      We had never done it, but had heard that it was being done by others. There
      is a microwave tower in Commack, but what goes on there..is a mystery. Never
      been there, done that. So, now we have learned the lesson of never passing on
      second-hand info about things that have not been personally vetted. Mea
      Culpa. Did you work with Radar or Microwave tech stuff at all, btw? Techies
      can do amazing things jerry-rigging devices when they want something! Se Ya.
    • Dave Emery
      ... Years ago (before about 1990) some telephone calls were transmatti ... -- Dave Emery N1PRE, die@die.com DIE Consulting, Weston, Mass. PGP fingerprint =
      Message 2 of 7 , Nov 1, 1999
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        On Mon, Nov 01, 1999 at 01:45:13PM -0500, Beehappy120@... wrote:
        > From: Beehappy120@...
        >
        > In a message dated 11/1/99 1:31:24 AM Pacific Standard Time,
        > coldwarcomms@onelist.com writes:
        >
        > << You can't listen to telephone calls transmitted via microwaves
        > using a scanner or cellphone. >>
        > I'm glad you pulled us up on this . Another apparent Urban Legend de-bunked.
        > We had never done it, but had heard that it was being done by others. There
        > is a microwave tower in Commack, but what goes on there..is a mystery. Never
        > been there, done that. So, now we have learned the lesson of never passing on
        > second-hand info about things that have not been personally vetted. Mea
        > Culpa. Did you work with Radar or Microwave tech stuff at all, btw? Techies
        > can do amazing things jerry-rigging devices when they want something! Se Ya.

        Years ago (before about 1990) some telephone calls were transmatti



        >
        >
        --
        Dave Emery N1PRE, die@... DIE Consulting, Weston, Mass.
        PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2 5D 27 BD B0 24 88 C3 18
      • Dave Emery
        ... Years ago (before about 1990 in the USA), many long distance and some local telephone calls were transmitted via analog microwave links that used
        Message 3 of 7 , Nov 1, 1999
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          On Mon, Nov 01, 1999 at 01:45:13PM -0500, Beehappy120@... wrote:
          > From: Beehappy120@...
          >
          > In a message dated 11/1/99 1:31:24 AM Pacific Standard Time,
          > coldwarcomms@onelist.com writes:
          >
          > << You can't listen to telephone calls transmitted via microwaves
          > using a scanner or cellphone. >>
          > I'm glad you pulled us up on this . Another apparent Urban Legend de-bunked.
          > We had never done it, but had heard that it was being done by others. There
          > is a microwave tower in Commack, but what goes on there..is a mystery. Never
          > been there, done that. So, now we have learned the lesson of never passing on
          > second-hand info about things that have not been personally vetted. Mea
          > Culpa. Did you work with Radar or Microwave tech stuff at all, btw? Techies
          > can do amazing things jerry-rigging devices when they want something! Se Ya.
          >
          Years ago (before about 1990 in the USA), many long distance and
          some local telephone calls were transmitted via analog microwave links
          that used FM-FDM-SSB modulation. Many of these links operated in the
          same band that big dish satellite TV systems use (C band 3700-4200 mhz),
          and it was readily possible to use a standard TVRO receiver and dish,
          LNA or LNB and feed to pick up long distance telephone calls being
          relayed in the C band frequency range (using the TD-n telco radios).
          Demodulating the calls required a tunable 0-15 mhz SSB receiver. All
          of this gear was widely available to the public, and whilst not a
          "scanner or cellphone" was hobby class equipment rather than highly
          specialized gear meant for telco or NSA use.

          And for techie type rf hackers with access to microwave test
          equipment and military or commercial surplus microwave components
          and subassemblies or systems it was readily possible to put together
          receiver and demodulator systems for the other bands (6 ghz, and 11 ghz
          particularly) used by telco analog microwave links. Not as easy
          as using a prebuilt TVRO setup, but very possible.

          Two things have changed since 1990 to make this much more
          difficult. First, while in 1977 68% of long distance calls went via
          these analog microwave circuits somewhere in the path, at the present
          time most long distance and local trunking is via buried optical fiber
          (Sonet rings) and relatively few telephone calls go out over radio
          links. Fiber has much greater capacity than radio (one single fiber
          can transmit as many bits per second of traffic as all the allocated telco
          microwave radio bands taken together), and has largely replaced microwave
          for carrying long distance and local calls and data. So there simply
          isn't much traffic on microwave radio links any more, and the chance
          of any given call going on a radio path is small.

          And second, the digital revolution has completely eliminated
          analog frequency division multiplex transmission from telco plants. What
          telco microwave radio links are still in service use digital modulation
          exclusively. The kind of digital modulation typically used is 256-QAM
          which is not currently used in any consumer electronic gear and the
          multiple levels of digital multiplexing used require quite sophisticated
          gear to demultiplex (not just a HF SSB receiver). Building a working
          receiving setup for these signals is a serious professional grade large
          scale engineering project and beyond most techie hackers.

          What of course is true is that whilst long distance telco
          trunking has become much harder to intercept, the wireless revolution
          means that the last mile of more and more telephone traffic flows over
          wireless links - cordless, cell and PCS which are often quite readily
          intercepted. Many of these can indeed be intercepted by a scanner or
          modified cellphone. Even the digital modulations now becoming more
          standard are usually not sent encrypted (shame on the US government for
          forcing this on us) and can often be decoded by using a standard phone
          of the same type with modified firmware and an external PC such as a
          laptop. This is typically widely available consumer gear, and whilst
          the software (which is the heart of this sort of hack) is not widely
          publicaly available, it is not impossible to write and has been written
          for lots of systems.


          And in fact many "microwave" towers (don't know about the one
          you mention) are now primarily cell and PCS base sites (and paging and
          other links too) with the former telco microwave links long since turned
          off - it costs less to leave the microwave antennas abandoned in place
          than remove them in many cases so the big horns are left up there to
          rust. And more modern microwave towers covered with dishes are often
          used to link remote cell sites back to the mobile switching office
          or link together sites used for trunked radio systems and the like.



          >
          --
          Dave Emery N1PRE, die@... DIE Consulting, Weston, Mass.
          PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2 5D 27 BD B0 24 88 C3 18
        • Ryan C Blake
          Mr. Emery, If you don t mind my asking, what is your professional background? From your command of the language and the DIE Consulting note at the end of
          Message 4 of 7 , Nov 2, 1999
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            Mr. Emery,

            If you don't mind my asking, what is your professional background?
            From your command of the language and the "DIE Consulting" note
            at the end of your message, you sound like a retiree (I do not mean
            to offend you in any way... I wish I was retired!)

            Your technical knowledge of both past and present technique sounds
            quite extensive.



            73,

            Ryan Blake, KD4RIX
            ___________________________________________________________________
            Get the Internet just the way you want it.
            Free software, free e-mail, and free Internet access for a month!
            Try Juno Web: http://dl.www.juno.com/dynoget/tagj.
          • Scott Peterson
            Hello from El Paso Texas!
            Message 5 of 7 , Nov 2, 1999
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              Hello from El Paso Texas!
            • Dave Emery
              ... I m an EE who has done both hardware and software development in the computer OS, digital hardware architecture and WAN and LAN networking areas. I worked
              Message 6 of 7 , Nov 2, 1999
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                On Tue, Nov 02, 1999 at 03:36:36PM -0600, Ryan C Blake wrote:
                > From: Ryan C Blake <ema432@...>
                >
                > Mr. Emery,
                >
                > If you don't mind my asking, what is your professional background?

                I'm an EE who has done both hardware and software development in
                the computer OS, digital hardware architecture and WAN and LAN
                networking areas. I worked as one of the software acolytes of an
                independantly designed and coded Unix kernel in the 80s's, architected
                and designed a couple of cpu boards on which the kernel ran, and then
                served as the digital architect of a pioneering AMD-29K risc based
                wire speed bridge/router for the LAN/WAN world - I also did some
                firmware work on the bridge/router and led a hardware team that
                produced a couple of new versions. My title during much of
                this was Senior Technical Consultant.

                RF and satellite communications has been a long term hobby
                interest of mine - I'm a ham and very long term radio listener, but
                aside from some occasional consulting I've not been professionally
                employed in the wireless industry.


                > >From your command of the language and the "DIE Consulting" note
                > at the end of your message, you sound like a retiree (I do not mean
                > to offend you in any way... I wish I was retired!)
                >
                I'm rather intrigued that my command of language (or lack
                thereof) makes me seem old enough to be retired. Granted, modern
                education is pretty mediocre, but still...

                Your guess that I might be retired is semi-accurate. I am
                married to a physician who is in quite lucrative (at least as
                far as such goes in the age of HMOs) practice as a pathologist
                in Beverely Mass and we have two children, one almost 5 and one
                15. I have chosen to stay home and be a daddy/nanny for my 5 year
                old son since he was born. This has made it much easier for my
                wife, and free of economic necessity it hasn't be a requirement
                that I work the usual 50-60 hour and weekends pace that I did
                while she was in medical school and residency.

                I am only 50, however, and am not convinced that I want
                to stay inactive for the rest of my life. So if I found the right
                R&D or even pure R niche in which to resume my career I probably
                am ready to do so as my son is now in pre-school and the intensity
                of the commitment less.


                > Your technical knowledge of both past and present technique sounds
                > quite extensive.
                >
                I'm a student of communications technology, and as a result
                of my listening over the years have had quite an activist interest
                in communications security and privacy issues, especially the
                encryption debate. This interest in security has led to examination
                and research of rf security over the years and is a strong
                professional interest at the moment.




                --
                Dave Emery N1PRE, die@... DIE Consulting, Weston, Mass.
                PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2 5D 27 BD B0 24 88 C3 18
              • Dave Emery
                ... Oh dear... My sincere apologies to the list... I carelessly replied to what I thought was a personally addressed off-list private email question and
                Message 7 of 7 , Nov 2, 1999
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                  On Tue, Nov 02, 1999 at 05:31:36PM -0500, Dave Emery wrote:
                  > From: Dave Emery <die@...>
                  >
                  > On Tue, Nov 02, 1999 at 03:36:36PM -0600, Ryan C Blake wrote:
                  > > From: Ryan C Blake <ema432@...>
                  > >
                  > > Mr. Emery,
                  > >
                  > > If you don't mind my asking, what is your professional background?
                  >
                  > I'm an EE who has done both hardware and software development in
                  > the computer OS, digital hardware architecture and WAN and LAN
                  > networking areas.

                  Oh dear...

                  My sincere apologies to the list... I carelessly replied to
                  what I thought was a personally addressed off-list private email
                  question and hastily sent out the answer without checking who
                  it was going to. I am most embarrassed to have my little bit
                  of puffery go out to who knows who on coldwarcomms... I guess
                  everyone on the list now knows more about me than they wanted to
                  or ever thought they would...
                  --
                  Dave Emery N1PRE, die@... DIE Consulting, Weston, Mass.
                  PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2 5D 27 BD B0 24 88 C3 18
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