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CDMA, why AMPS will hang around.

Discussion in 'alt.cellular.verizon' started by N9WOS, Dec 12, 2003.

  1. N9WOS

    N9WOS Guest

    Some people may say that AMPS will be taken off
    as soon as the FCC allows it.
    My opinion is it probably won't.
    Some say they will take it off to make all
    the space available for CDMA carriers.
    but that won't exactly work.

    The CDMA carriers don't fit the cellular band perfectly.
    There is around 700khz of leftover space when you put all
    the CDMA carriers in the primary cellular bands that it can hold.
    And you have close to 1Mhz of leftover bandwidth
    on the extended B band.

    If they take AMPS off, what will they do with the bandwidth?

    So, as long as the amps channels are getting used enough to
    pay for the operation of the equipment, the AMPS capability
    will stay intact.
     



    › See More: CDMA, why AMPS will hang around.
  2. Blerg

    Blerg Guest

    >From: "N9WOS" x-no-archive:yes n9wos@nobug.worldnet.att.net
    >Date: 12/12/2003 3:11 PM Eastern Standard Time:

    "...If they take AMPS off, what will they do with the bandwidth?.."

    I'm sure they will re-jigger their coding to use the extra bandwith for CDMA.
    Since CDMA is a form of Spread-Spectrum, they don't need specific "discrete
    channels or freqencies" like Analog or GSM does & it should be easy for them to
    "widen" the spread to take advantage of more bandwith & increase cell capacity.
    I think, howver, Analog won't be shut off "as soon as" the FCC allows,
    mainly because of the roaming revenue.
    Unless sonething changes, In many areas, AT& T, Cigular & T-mobile Roam on
    VZW & vice/versa since they don't have a system in the area. GSM/TDMA/CDMA
    phones will revert to analog if the only digital in the area is not the same.
    Once the roaming revenue becomes little or none, you will see analog being
    shut off in stages. 1st in areas where all cross roaming is to a compatible
    digital carrier, then lastly in the former mentioned areas.
     
  3. Larry W4CSC

    Larry W4CSC Guest

    I'm getting OnStar installed in a Kevlar armored car a friend of mine
    uses for a mobile check cashing business on paydays at the gates of
    shipyards around here, as soon as I get the A/C, genset, lights,
    bullhorn/siren and stuff installed. It'll be AMPS.....when it counts.



    On Fri, 12 Dec 2003 20:11:10 GMT, "N9WOS"
    <n9wos@nobug.worldnet.att.net> wrote:

    >Some people may say that AMPS will be taken off
    >as soon as the FCC allows it.
    >My opinion is it probably won't.
    >Some say they will take it off to make all
    >the space available for CDMA carriers.
    >but that won't exactly work.
    >
    >The CDMA carriers don't fit the cellular band perfectly.
    >There is around 700khz of leftover space when you put all
    >the CDMA carriers in the primary cellular bands that it can hold.
    >And you have close to 1Mhz of leftover bandwidth
    >on the extended B band.
    >
    >If they take AMPS off, what will they do with the bandwidth?
    >
    >So, as long as the amps channels are getting used enough to
    >pay for the operation of the equipment, the AMPS capability
    >will stay intact.
    >
    >


    Larry W4CSC

    NNNN
     
  4. N9WOS

    N9WOS Guest


    > I'm sure they will re-jigger their coding to use the extra bandwith for

    CDMA.
    > Since CDMA is a form of Spread-Spectrum, they don't need specific

    "discrete
    > channels or freqencies" like Analog or GSM does & it should be easy for

    them to
    > "widen" the spread to take advantage of more bandwith & increase cell

    capacity.

    Ummmm....... It isn't that easy.
    The coding sequence is hardware based.
    To "re-jigger" the coding, they would have to come out with
    completely new phones that are able to use those "re-jiggered" modes. :)
     
  5. Al Klein

    Al Klein Guest

    On Sat, 13 Dec 2003 00:15:03 GMT, nospam@home.com (Larry W4CSC) posted
    in alt.cellular.verizon:

    >I'm getting OnStar installed in a Kevlar armored car a friend of mine
    >uses for a mobile check cashing business on paydays at the gates of
    >shipyards around here, as soon as I get the A/C, genset, lights,
    >bullhorn/siren and stuff installed. It'll be AMPS.....when it counts.


    Which is why aircraft still use ancient modulation. When you really
    need it ...
     
  6. Blerg

    Blerg Guest

    x-no-archive:yes From: "N9WOS" n9wos@nobug.worldnet.att.net :

    " It isn't that easy. The coding sequence is hardware based. To "re-jigger" the
    coding, they would have to come out with completely new phones that are able to
    use those "re-jiggered" modes. :).."

    According to a VZW Cell site TEch I spoke to, it isn't any problem & doesn't
    involve a "Mode" change. It will still be CDMA mode, & still use the
    frequencies already allocated by the FCC & in the cellphones & cellsites . He
    says that even now, different cellsites have different levels of analog vs
    Digital Bandwith & a frequency that is analog in one cell could be digital in
    another. The phones & systems are "smart" enough to adapt. There are cells
    recently installed that are 100% digital & use all the bandwith for CDMA, &
    there are other cells with varying degrees of the bandwith still analog,
    anywhere from 5 to 50%, depending on location. Years ago, a cell's bandwith
    could have been over 90% analog vs. digital. He is called in all the time to
    remove analog bandwith from an individual cell & replace it with digital.
    He says the coding & bandwith can chage from cell to cell, & their system &
    phones auto adapt as calls are handed off from cell to cell. He foud it
    amusing to think you would need a new phone or mode each time they added or
    deleted CDMA bandwith, & said people would need a different phone monthly, &
    even going from cell to cell using that logic.
    He seemed to know what he was talking about.
     
  7. N9WOS

    N9WOS Guest

    > According to a VZW Cell site TEch I spoke to, it isn't any problem &
    doesn't
    > involve a "Mode" change. It will still be CDMA mode, & still use the
    > frequencies already allocated by the FCC & in the cellphones & cellsites .

    He
    > says that even now, different cellsites have different levels of analog

    vs
    > Digital Bandwith & a frequency that is analog in one cell could be digital

    in
    > another.


    You are not grasping what I am getting at.
    Yes you can fill the band with mixed amounts of digital and analog signals.
    And you can have a chunk of frequencies on one tower being used for analog
    while they are being used for digital on another tower.
    All currently existing phones, and future phones have no problem with that.

    But that isn't what I am talking about.
    You assign spectrum for CDMA carriers in 1.25Mhz chunks.
    A CDMA carrier needs a 1.25Mhz contiguous chunk of spectrum to operate.
    It can't have any major overlap with any other CDMA carrier.
    The 1.25Mhz bandwidth is hardware set.
    When the tower changes it's bandwidth percentage for it's operating modes,
    it must do it in 1.25Mhz chunks, which is the largest aggregate of the
    operating modes.

    If you fill the entire band with 1.25Mhz chunks, you will have space left
    over.
    Same as if you fill a box with sand(AMPS), you will have a very small amount
    of space left in-between the grains.
    But if you fill the box with 3inch diameter rocks(CDMA), you will have a lot
    of open space between the rocks left over.

    In the A band, after you put in the eighth CDMA carrier,
    you will have around 700Khz left over on the top side and
    200Khz left over on the bottom side for the guard band.
    You can't put another CDMA carrier in that space.
    You can't put a 20 pound concrete block in a tea cup.
    It isn't going to fit.

    So why not do the equivalent of pouring sand in around
    the 3inch rocks to fill up the space.
    Because, in that 700Khz +200Khz space, you have enough room for a
    complete control channel system and a moderate number of traffic channels.
     
  8. (Ahem) You're sure the bureaucratic inertia involved with changing
    the FAA's Technical Standards Orders isn't a factor?
    And that's not even mentioning coordinating the same changes
    throughout all the rest of the world. :-(

    I think that the technology isn't even a detectable part of that =
    problem.
    ---JRC---

    "Al Klein" <rukbat@pern.org> wrote in message =
    news:mv5ltvg9dlv4ejvrdshq81mfbj0l53h2b2@Pern.rk...
    >=20
    > Which is why aircraft still use ancient modulation. When you really
    > need it ...
     
  9. "Blerg" <dirtmeat@aol.com.bex> wrote in message
    news:20031212161100.21755.00000480@mb-m26.aol.com...
    > >From: "N9WOS" x-no-archive:yes n9wos@nobug.worldnet.att.net
    > >Date: 12/12/2003 3:11 PM Eastern Standard Time:

    > "...If they take AMPS off, what will they do with the bandwidth?.."
    >
    > I'm sure they will re-jigger their coding to use the extra bandwith for

    CDMA.
    > Since CDMA is a form of Spread-Spectrum, they don't need specific

    "discrete
    > channels or freqencies" like Analog or GSM does & it should be easy for

    them to
    > "widen" the spread to take advantage of more bandwith & increase cell

    capacity.
    > I think, howver, Analog won't be shut off "as soon as" the FCC

    allows,
    > mainly because of the roaming revenue.


    Not just that. The emergency call boxes are AMPS. On-Star is AMPS. It is
    common for governments and businesses to pay to keep a vital product or
    service in production when the producer would otherwise cease providing the
    product or service. The loss of AMPS would make On-Star a joke since it
    would not function in many areas where it is most needed. Similarly, no
    digital technology has the range of AMPS, so replacing call boxes with
    digital versions would not work.
     
  10. Charles

    Charles Guest

    In article <S1ICb.2346$Pg1.1994@newsread1.news.pas.earthlink.net>,
    Steven M. Scharf <scharf.steven@linkearth.net> wrote:

    > Similarly, no digital technology has the range of AMPS, so replacing
    > call boxes with digital versions would not work.


    They may very well leave some AMPS in place for On-Star and the call
    boxes. However they could discontinue selling cell phones or regular
    cell plans with Analog.

    --
    Charles
     
  11. Blerg

    Blerg Guest

    x-no-archive:yes
    .. It was my understanding that new vehicles w/OnStar have been digital for
    over a year now...
     
  12. Larry W4CSC

    Larry W4CSC Guest

    On Sat, 13 Dec 2003 16:10:57 GMT, "N9WOS"
    <n9wos@nobug.worldnet.att.net> wrote:

    >
    >So why not do the equivalent of pouring sand in around
    >the 3inch rocks to fill up the space.
    >Because, in that 700Khz +200Khz space, you have enough room for a
    >complete control channel system and a moderate number of traffic channels.
    >

    "I KNOW! I KNOW", Johnny yelled to the teacher, waving his hand in
    the air.

    "It makes digital look bad if they see someone talking on a bagphone
    in the CDMA toyphone DEAD ZONE....."..............(c;

    Be nice to the screwed customers and let them use your powerful AMPS
    phone if theirs is dead. They just KNOW from all the propagated
    bullshit AMPS is noisy and useless, right?.....(c;

    NOT!

    Larry W4CSC

    NNNN
     
  13. Larry W4CSC

    Larry W4CSC Guest

    On Sat, 13 Dec 2003 17:31:30 GMT, "Steven M. Scharf"
    <scharf.steven@linkearth.net> wrote:

    >
    >Not just that. The emergency call boxes are AMPS. On-Star is AMPS. It is
    >common for governments and businesses to pay to keep a vital product or
    >service in production when the producer would otherwise cease providing the
    >product or service. The loss of AMPS would make On-Star a joke since it
    >would not function in many areas where it is most needed. Similarly, no
    >digital technology has the range of AMPS, so replacing call boxes with
    >digital versions would not work.
    >

    Oh, oh....this is gonna stir up trouble....(c;



    Larry W4CSC

    NNNN
     
  14. Larry W4CSC

    Larry W4CSC Guest

    They already have, Charles. The carriers are doing everything they
    can to kill it.

    On Sat, 13 Dec 2003 13:09:50 -0500, Charles
    <fort@his.com.remove.invalid> wrote:

    >In article <S1ICb.2346$Pg1.1994@newsread1.news.pas.earthlink.net>,
    >Steven M. Scharf <scharf.steven@linkearth.net> wrote:
    >
    >> Similarly, no digital technology has the range of AMPS, so replacing
    >> call boxes with digital versions would not work.

    >
    >They may very well leave some AMPS in place for On-Star and the call
    >boxes. However they could discontinue selling cell phones or regular
    >cell plans with Analog.
    >
    >--
    >Charles


    Larry W4CSC

    NNNN
     
  15. Larry W4CSC

    Larry W4CSC Guest

    On 13 Dec 2003 18:21:12 GMT, dirtmeat@aol.com.bex (Blerg) wrote:

    >x-no-archive:yes
    > .. It was my understanding that new vehicles w/OnStar have been digital for
    >over a year now...


    Maybe that's why their webpage onstar.com has been dead for over a
    week, now.....??


    Larry W4CSC

    NNNN
     
  16. Al Klein

    Al Klein Guest

    On Sat, 13 Dec 2003 16:20:58 GMT, "John R. Copeland"
    <jcopelan@columbus.rRr.com> posted in alt.cellular.verizon:

    >(Ahem) You're sure the bureaucratic inertia involved with changing
    >the FAA's Technical Standards Orders isn't a factor?


    Ever try to separate one AM signal out of another? Know what "capture
    ratio" is?

    If you absolutely, positively have to be able to tell what the pilot
    said, even after the plane crashed, and all you have is a recording of
    a loud heterodyne and 2 voices, you can separate out a clear voice.
    If planes used FM there might only be one voice, and it might be the
    wrong one. And the better the receiver, the less difference between
    the 2 signal strengths for one to eliminate the other - to the point
    that the tower doesn't even know that one pilot is declaring a
    disaster.

    >And that's not even mentioning coordinating the same changes
    >throughout all the rest of the world. :-(


    Many engineering changes are made internationally - if they're needed.
    Changing the aircraft radio system to FM is needed to NOT be done.

    >I think that the technology isn't even a detectable part of that problem.


    Then you don't have much experience working with the technology.
     
  17. "Al Klein" <rukbat@pern.org> wrote in message =
    news:kventvk0aued68kr345d8otukm7312uqln@Pern.rk...
    > On Sat, 13 Dec 2003 16:20:58 GMT, "John R. Copeland"
    > <jcopelan@columbus.rRr.com> posted in alt.cellular.verizon:
    >=20
    >=20
    > >I think that the technology isn't even a detectable part of that =

    problem.
    >=20
    > Then you don't have much experience working with the technology.


    Actually, Al, I have 50 years of experience working both with the =
    technology
    AND with the bureaucracy.

    I greatly prefer the technology.
    ---JRC---
     
  18. Al Klein

    Al Klein Guest

    On Sun, 14 Dec 2003 03:23:15 GMT, "John R. Copeland"
    <jcopelan@columbus.rRr.com> posted in alt.cellular.verizon:

    >"Al Klein" <rukbat@pern.org> wrote in message news:kventvk0aued68kr345d8otukm7312uqln@Pern.rk...
    >> On Sat, 13 Dec 2003 16:20:58 GMT, "John R. Copeland"
    >> <jcopelan@columbus.rRr.com> posted in alt.cellular.verizon:


    >> >I think that the technology isn't even a detectable part of that problem.


    >> Then you don't have much experience working with the technology.


    >Actually, Al, I have 50 years of experience working both with the technology


    So your post was tongue-in-cheek? Made after a week without sleep?
    Changing the aircraft system to FM has been proposed to death and
    consigned to death many times - for purely technical reasons. Since
    it would be so technically disastrous, there's no need to even discuss
    the logistics.
     
  19. Isaiah Beard

    Isaiah Beard Guest

    N9WOS wrote:

    > Some people may say that AMPS will be taken off
    > as soon as the FCC allows it.
    > My opinion is it probably won't.
    > Some say they will take it off to make all
    > the space available for CDMA carriers.
    > but that won't exactly work.
    >
    > The CDMA carriers don't fit the cellular band perfectly.
    > There is around 700khz of leftover space when you put all
    > the CDMA carriers in the primary cellular bands that it can hold.


    Well, I think at this point, the carriers will have to do a cost benefit
    analysis. For their 700kHz, the carrier doing the CDMA overlay will get
    a theoretical 10-fold increase in call capacity. But realistically,
    let's say, a 5 to 7-fold increase.

    So, they can get anywhere between five to seven times the number of
    users than can fit on AMPS, or continue to run AMPS to fully utilize the
    bandwidth assigned to them at a loss of all that capacity.

    I have a feeling that if they feasibly can, they'll do the overlay
    anyway, and perhaps use the remaining 700kHz as holdover AMPS channels.
    At 30kHz per AMPS channel, that leaves room for 23 channels.




    --
    E-mail fudged to thwart spammers.
    Transpose the c's and a's in my e-mail address to reply.
     
  20. Larry W4CSC

    Larry W4CSC Guest

    That would be true if it were the carriers' airwaves.

    But, alas, it's not. They are allowed to use our airwaves, IF they
    follow OUR rules.

    Our rules state they will provide AMPS service at least until Feb 16,
    2008. End of problem.


    On Tue, 16 Dec 2003 15:50:11 -0500, Isaiah Beard
    <sacredpoet@sacredpoet.com> wrote:

    >N9WOS wrote:
    >
    >> Some people may say that AMPS will be taken off
    >> as soon as the FCC allows it.
    >> My opinion is it probably won't.
    >> Some say they will take it off to make all
    >> the space available for CDMA carriers.
    >> but that won't exactly work.
    >>
    >> The CDMA carriers don't fit the cellular band perfectly.
    >> There is around 700khz of leftover space when you put all
    >> the CDMA carriers in the primary cellular bands that it can hold.

    >
    >Well, I think at this point, the carriers will have to do a cost benefit
    >analysis. For their 700kHz, the carrier doing the CDMA overlay will get
    >a theoretical 10-fold increase in call capacity. But realistically,
    >let's say, a 5 to 7-fold increase.
    >
    >So, they can get anywhere between five to seven times the number of
    >users than can fit on AMPS, or continue to run AMPS to fully utilize the
    >bandwidth assigned to them at a loss of all that capacity.
    >
    >I have a feeling that if they feasibly can, they'll do the overlay
    >anyway, and perhaps use the remaining 700kHz as holdover AMPS channels.
    > At 30kHz per AMPS channel, that leaves room for 23 channels.
    >
    >
    >
    >
    >--
    >E-mail fudged to thwart spammers.
    >Transpose the c's and a's in my e-mail address to reply.
    >


    Larry W4CSC

    NNNN
     

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