Professional Web Applications Themes

Hee-hee-hee Airport Range of 16 Miles! - Mac Networking

Mark Conrad wrote: > If I read the table at this website correctly, under some cirstances > the range can be as much as 16 miles. With one-watt transmitters and directional antennae, the maximum is about 4 km. But you have to be a spook to buy and operate such equipment....

  1. #1

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    Mark Conrad wrote:
    > If I read the table at this website correctly, under some cirstances
    > the range can be as much as 16 miles.
    With one-watt transmitters and directional antennae, the maximum
    is about 4 km. But you have to be a spook to buy and operate
    such equipment.
    George Williams Guest

  2. #2

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <140720031235057085%nospamiam.invalid>,
    Mark Conrad <nospamiam.invalid> wrote:
    > Surfing the web, I stumbled across this site:
    >
    > [url]www.proxim.com/products/all/tsunami_mp11/accessories/ranges.html[/url]
    >
    > They sell systems plus antennas that claim to extend the range of
    > Airport-like systems.
    >
    > If I read the table at this website correctly, under some cirstances
    > the range can be as much as 16 miles.
    >
    > Check it out, see what you can make of it.
    >
    > Also, if you don't mind voiding your Airport base-station's warranty,
    > look at page 56 of the present August 2003 Macworld magazine:
    >
    > "Extend Your Airport's Range"
    >
    > Betcha lotsa 'gotchas' for anyone planning this approach.
    >
    > ...still, a modest conservative approach to extending Airport's range
    > might work, after a fashion.
    Most likely it'd be much easier to just get a range-extender from
    <http://www.hyperlinktech.com/>. They've got models that work with even
    the original "graphite" base stations. Not 16 miles by any stretch, but
    a good deal more than the stock hardware provides.

    --
    Tom "Tom" Harrington
    Macaroni, Automated System Maintenance for Mac OS X.
    Version 1.4: Best cleanup yet, gets files other tools miss.
    See [url]http://www.atomicbird.com/[/url]
    Tom Harrington Guest

  3. #3

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <3F133C8B.6DB0AF31mac.com>,
    George Williams <nyar1ath0tepmac.com> wrote:
    >Mark Conrad wrote:
    >
    >> If I read the table at this website correctly, under some cirstances
    >> the range can be as much as 16 miles.
    >
    >With one-watt transmitters and directional antennae, the maximum
    >is about 4 km. But you have to be a spook to buy and operate
    >such equipment.
    No, you don't. 1W is the FCC limit for transmissions in the 2.4Ghz
    unlicensed band. Directional antennas are not restricted for purchase
    either, though you can only use an antenna with 6dBi gain if you
    transmit with the full 1W power.

    --
    Matthew T. Russotto [email]mrussottospeakeasy.net[/email]
    "Extremism in defense of liberty is no vice, and moderation in pursuit
    of justice is no virtue." But extreme restriction of liberty in pursuit of
    a modi of security is a very expensive vice.
    Matthew Russotto Guest

  4. #4

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <user-F5298E.17070915072003scream.auckland.ac.nz>, Peter
    KERR <userhost.domain> wrote:
    > [url]www.pbs.org/cringely/pulpit/pulpit20020207.html[/url]
    Fantastic article.

    Mark-
    Mark Conrad Guest

  5. #5

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <160720030818431933%nospamiam.invalid>, Mark Conrad
    <nospamiam.invalid> wrote:
    > I can think of a legal way around that. (perhaps)<g>
    >
    > Let's assume we have two networks of computers, a modest 5 miles away
    > from each other, out in the country.
    >
    > Nothing (legally) to stop each network from using a high-gain parabolic
    > antenna for _receive-only_ , to receive the small "cloud" of Airport
    > from the other network five miles away.
    >
    > Each high-gain parabolic antenna is receive-only, which makes it legal.
    >
    > ...but the net effect is that you still have two-way communication
    > between the two networks of computers 5 miles apart, via Airport.
    The only flaw in your plan is that 802.11 access points typically don't
    have separate antennas for sending and receiving. I've never seen one
    that does, in fact.

    --
    Jerry Kindall, Seattle, WA <http://www.jerrykindall.com/>

    When replying by e-mail, use plain text ONLY to make sure I read it.
    Due to spam and viruses, I filter all mail with HTML or attachments.
    Jerry Kindall Guest

  6. #6

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <160720030818431933%nospamiam.invalid>,
    Mark Conrad <nospamiam.invalid> wrote:
    >In article <tgadnX0fRukDvYmiXTWc-wspeakeasy.net>, Matthew Russotto
    ><russottograce.speakeasy.net> wrote:
    >
    >I can think of a legal way around that. (perhaps)<g>
    >
    >Let's assume we have two networks of computers, a modest 5 miles away
    >from each other, out in the country.
    >
    >Nothing (legally) to stop each network from using a high-gain parabolic
    >antenna for _receive-only_ , to receive the small "cloud" of Airport
    >from the other network five miles away.
    >
    >Each high-gain parabolic antenna is receive-only, which makes it legal.
    Sure, you could use a lower-gain antenna for transmit and a big
    honking dish for receive. But with only 5 miles, no need for tricks.
    You can do it with a pair of ordinary 100mw transmitters and 16dBi
    antennas. (which is that same 36dBm). There's also a "3 for 1" rule
    in a point-to-point application -- for each dB you reduce transmit
    power below 1W (30dBm), you can increase antenna gain 3 dB. So with
    those 100mw (20 dBm) transmitters you can use up to a 46dBi directional
    antenna, which is plenty of gain for a long network.
    --
    Matthew T. Russotto [email]mrussottospeakeasy.net[/email]
    "Extremism in defense of liberty is no vice, and moderation in pursuit
    of justice is no virtue." But extreme restriction of liberty in pursuit of
    a modi of security is a very expensive vice.
    Matthew Russotto Guest

  7. #7

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <160720030858386987%jerrykindallnospam.invalid> , Jerry
    Kindall <jerrykindallnospam.invalid> wrote:
    > The only flaw in your plan is that 802.11 access points typically don't
    > have separate antennas for sending and receiving. I've never seen one
    > that does, in fact.

    Lemme see if I have this correct.

    Does this mean that one Airport computer can't be listen-only?

    In other words, just in order to "listen" there has to be some sort of
    periodic two-way traffic? (assume no passwords)

    Mark-
    Mark Conrad Guest

  8. #8

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <160720031155233357%nospamiam.invalid>,
    Mark Conrad <nospamiam.invalid> wrote:
    >
    >Does this mean that one Airport computer can't be listen-only?
    Yes. 802.11b is inherently bi-directional.



    --
    Matthew T. Russotto [email]mrussottospeakeasy.net[/email]
    "Extremism in defense of liberty is no vice, and moderation in pursuit
    of justice is no virtue." But extreme restriction of liberty in pursuit of
    a modi of security is a very expensive vice.
    Matthew Russotto Guest

  9. #9

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <_mGdnfX8Id2bP4iiXTWc-wspeakeasy.net>, Matthew Russotto
    <russottograce.speakeasy.net> wrote:
    > In article <160720031155233357%nospamiam.invalid>,
    > Mark Conrad <nospamiam.invalid> wrote:
    > >
    > >Does this mean that one Airport computer can't be listen-only?
    >
    > Yes. 802.11b is inherently bi-directional.
    And it needs to be, because TCP/IP needs to send back an ack for each
    packet.

    --
    Jerry Kindall, Seattle, WA <http://www.jerrykindall.com/>

    When replying by e-mail, use plain text ONLY to make sure I read it.
    Due to spam and viruses, I filter all mail with HTML or attachments.
    Jerry Kindall Guest

  10. #10

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <160720031744308308%nospamiam.invalid>, Mark Conrad
    <nospamiam.invalid> wrote:
    > If I was doing somewhat the same "bank-shot", I think I would have
    > installed one of those big discarded TV satellite dishes for the
    > reflector instead of the yagi approach.
    Er, I forgot to mention the old feed horn would have to be yanked off,
    and replaced with a corner reflector or something to re-direct the
    energy back out of the old dish at the new 'banked' angle.

    ....because those old TV satellite dishes are not designed to be used as
    reflectors.

    Mark-
    Mark Conrad Guest

  11. #11

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <bf48ag$avr6s$1ID-134476.news.uni-berlin.de>,
    <davehinzspamcop.net> wrote:
    > Someone who looks an awful lot like Matthew Russotto
    > <russottograce.speakeasy.net> wrote:
    >
    > > Sure, you could use a lower-gain antenna for transmit and a big
    > > honking dish for receive. But with only 5 miles, no need for tricks.
    > > You can do it with a pair of ordinary 100mw transmitters and 16dBi
    > > antennas. (which is that same 36dBm).
    >
    > OK, so what is the power output of a Linksys WAP11, I wonder? Linksys
    > claims 100mW, the FCC says it's 38mW - which figure should I use to make
    > sure my design won't exceed legal limits? I don't have the gear
    > to measure it, so I have to use someone's numbers...but whose?
    >
    > Dave Hinz
    >
    Dunno, sounds to me like Linksys might have been measuring the 100mW
    _input_ to the final amplifier, which is easy enough to do.

    Because of normal losses within the 2.4 Ghz amplifier, the FCC figure
    of 38mW might well have been the _output_ RF from the amplifier, which
    is always difficult for normal mortals to measure accurately - - -
    dunno.

    I always thought the FCC reg's pertained to input power, like they do
    with ham radio. That is very easy to measure, i.e. voltage times amps
    at the final amplifier.

    Mark-
    Mark Conrad Guest

  12. #12

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <bf48ag$avr6s$1ID-134476.news.uni-berlin.de>,
    <davehinzspamcop.net> wrote:
    >Someone who looks an awful lot like Matthew Russotto <russottograce.speakeasy.net> wrote:
    >
    >> Sure, you could use a lower-gain antenna for transmit and a big
    >> honking dish for receive. But with only 5 miles, no need for tricks.
    >> You can do it with a pair of ordinary 100mw transmitters and 16dBi
    >> antennas. (which is that same 36dBm).
    >
    >OK, so what is the power output of a Linksys WAP11, I wonder? Linksys
    >claims 100mW, the FCC says it's 38mW - which figure should I use to make
    >sure my design won't exceed legal limits?
    There are several versions of the Linksys WAP11. Probably if you look
    up the FCC ID on the back at the FCC site, you can get the numbers
    Linksys provided to the FCC for that particular version.
    --
    Matthew T. Russotto [email]mrussottospeakeasy.net[/email]
    "Extremism in defense of liberty is no vice, and moderation in pursuit
    of justice is no virtue." But extreme restriction of liberty in pursuit of
    a modi of security is a very expensive vice.
    Matthew Russotto Guest

  13. #13

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <160720031744308308%nospamiam.invalid>,
    Mark Conrad <nospamiam.invalid> wrote:
    >In article <F9ednUyd-Ob2A4iiXTWc-gspeakeasy.net>, Matthew Russotto
    ><russottograce.speakeasy.net> wrote:
    >
    >> But with only 5 miles, no need for tricks.
    >
    >I was wondering about that, reducing the power to 100 milliwatts and
    >then more than making up for the reduced power with a (legal) high-gain
    >yagi or parabolic antenna.
    >
    >The exotic antennas would be legal becaused of the reduced power.
    Yep. Check out the wireless forum at broadbandreports.com, there's a
    few first-hand reports of working long links, though you do have to
    wade through the many "waaa, my wireless doesn't work with XP" threads.
    --
    Matthew T. Russotto [email]mrussottospeakeasy.net[/email]
    "Extremism in defense of liberty is no vice, and moderation in pursuit
    of justice is no virtue." But extreme restriction of liberty in pursuit of
    a modi of security is a very expensive vice.
    Matthew Russotto Guest

  14. #14

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <170720030311195528%nospamiam.invalid>,
    Mark Conrad <nospamiam.invalid> wrote:
    >...because those old TV satellite dishes are not designed to be used as
    >reflectors.
    Why use a parabola at all? If you're doing a bank shot, a simple
    sheet (or grid) of metal should do it, if you can figure out how to
    mount it.

    --
    Matthew T. Russotto [email]mrussottospeakeasy.net[/email]
    "Extremism in defense of liberty is no vice, and moderation in pursuit
    of justice is no virtue." But extreme restriction of liberty in pursuit of
    a modi of security is a very expensive vice.
    Matthew Russotto Guest

  15. #15

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <jcmcndV7uMf7YouiXTWc-wspeakeasy.net>, Matthew Russotto
    <russottograce.speakeasy.net> wrote:
    > >...because those old TV satellite dishes are not designed to be used as
    > >reflectors.
    >
    > Why use a parabola at all? If you're doing a bank shot, a simple
    > sheet (or grid) of metal should do it, if you can figure out how to
    > mount it.
    Well yes, that would work, especially if you could curve the sheet of
    metal a bit to kinda counter the tendency of the energy to keep
    spreading after it was reflected ;-)

    Assume the source yagi had a beam spread of about 15 degrees on its
    main lobe, it would keep spreading at 15 degrees after the reflection
    from a flat sheet.

    To see the effect of a parabola reflector, get one of those big 6v
    Coleman lanterns, out the bulb and replace the bulb with a tiny
    flat dental mirror, to which you tape a 'diopter' lens that has a
    smallish convex curve to it.

    That dental-mirror/lens combination will kick any light back into the
    Coleman's parabola, while at the same time taking much of the 'spread'
    out of the reflected light.

    Now illuminate the Coleman's parabola from a distance with an ordinary
    flashlight, and note the reflection from the Coleman's parabola, which
    should be more intense than the reflection from a flat mirror, due to
    "killing" some spread at the reflector.

    The same effect should be obtainable at 2.4 Ghz by placing a small
    custom shallow concave reflector-sheet at the focal point of the big
    parabola, to kick back the RF energy into the big dish, while at the
    same time removing some "spread" from the energy.

    Should be able to adjust the thing with a jury-rigged
    "RF-Field-Strength-Meter".

    (a Mac powerbook with its ordinary indicator of the strength of the
    Airport signal)

    With any luck, the RF energy should arive at the big parabola with a
    spread of 15 degrees, and leave with a reduced spread of 5 degrees.

    What will probably shoot this scheme down is that 2.4 Ghz might be too
    low a frequency for the custom reflector-sheet to handle.

    Somehow, we gotta get Airport's legal range up to 20 miles, ya know.

    This kinda reminds me of my ham radio days, when I successfully
    contacted another ham in Florida (from California) - using 100-mW on
    the 20-meter band.

    Mark-
    Mark Conrad Guest

  16. #16

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    >
    > > Have you done the wattage/gain/spread calculations?
    >
    > Naw, that is too cold blooded, it would take all the fun out of it ;-)
    Hey, it's sometimes fun doing the math ;-) I once calculated path loss
    on a 160 mhz mountain ridge difraction link using tables NASA had
    published for propagation on the moon. Practical result was within a few
    dB.
    > > Does a high enough gain antenna exist, with a narrow enough
    > > beam, that could take the legal output of the airport
    > > and still be within FCC regs?
    >
    > Cushcraft makes a 2.4 Ghz 21 dB parabolic mesh dish antenna which that
    > guy was using to make the bank-shot off 1,887 foot Bennett Mountain --
    > and straight into downtown Santa Rosa. He was using 100mW.
    >
    > Supposedly any kind of antenna is legal at that power.
    >
    > According to his article, Bennett Mountain is 1.5 miles away from his
    > house, and from the mountain into downtown Santa Rosa is approximately
    > 5 miles, for a total path length of 6.5 miles.
    He was lucky his two pair of back-back yagis had good geometry. It's
    easy to get one antenna cancelling the other...
    > Someone here, earlier in this thread, posted the link to his article.
    >
    > It scrolled off my newsreader. I think his name is David Cringely.
    [url]http://www.pbs.org/cringely/oldhat.html[/url]

    has all his articles, this particular was at 07 Feb 2002.
    He promised a followup, but a quick flick thru the headers
    was too distracting...
    Peter KERR Guest

  17. #17

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    Jerry Kindall <jerrykindallnospam.invalid> wrote:
    > Robert X. Cringely, but that's a pen name...
    I thought Bic and Paper*Mate were pen names...

    --
    Mike Rosenberg

    <http://www.macconsult.com>
    <http://bogart-tribute.net>
    Mike Rosenberg Guest

  18. #18

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <user-8BF8E6.19231920072003scream.auckland.ac.nz>, Peter
    KERR <userhost.domain> wrote:
    > Hey, it's sometimes fun doing the math ;-) I once calculated path loss
    > on a 160 mhz mountain ridge difraction link using tables NASA had
    > published for propagation on the moon. Practical result was within a few
    > dB.
    That brings up a topic that has been bothering me for years.

    When Einstein announced his 1.94 seconds-of-arc that the gravity of the
    sun would bend light from a distant star, and they verified Einstein's
    calculation during a solar eclipse, then someone _must_ have known
    exactly how much ordinary diffraction was also influencing the result,
    and made allowance for diffraction.

    Seems to me that the bend of electromagnetic energy due to diffraction
    is not all that easy to calculate exactly, but I guess I am wrong.

    Amazing things that are done with math', wish I knew more about it, but
    it is very intimidating to me. I have never been able to find a gentle
    learning ramp for math'.

    Mark-
    Mark Conrad Guest

  19. #19

    Default Re: Hee-hee-hee Airport Range of 16 Miles!

    In article <200720030856490526%nospamiam.invalid>,
    Mark Conrad <nospamiam.invalid> wrote:
    >
    > Seems to me that the bend of electromagnetic energy due to diffraction
    > is not all that easy to calculate exactly, but I guess I am wrong.
    >
    You can do anything with Bessel functions,
    even control thread drift ;-)
    Peter KERR Guest

  20. #20

    Default Woz: wOzNet to cover 100 square miles?

    Mark Conrad wrote:
    >
    > In article <user-B61296.14473021072003scream.auckland.ac.nz>, Peter
    > KERR <userhost.domain> wrote:
    >
    > > You can do anything with Bessel functions,
    > > even control thread drift ;-)
    > Thread drift has a definite bearing on the subject at hand.
    Not to mention that Woz and his new company (Wheels of Zeus)
    have come forward with the concept of 900 MHz networks for private
    citizens covering a range of 100 sq. miles. Why 900 MHz instead
    of 2.4 GHz or 5.6 GHz, you ask? Because it's for keeping track of
    garage doors and stray dogs, not for downloading "Matrix 3" or
    cruising the alt.binaries.... hierarchy.
    George Williams Guest

Page 1 of 2 12 LastLast

Similar Threads

  1. Replies: 1
    Last Post: August 2nd, 08:17 PM
  2. Replies: 1
    Last Post: August 2nd, 08:00 PM
  3. #24909 [NEW]: rand function with range always returns low value of range
    By a0 at hush dot com in forum PHP Development
    Replies: 0
    Last Post: August 1st, 07:37 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139