Any EE experts out there?

Discussion in 'Wireless Networking' started by hermes, Nov 16, 2005.

  1. hermes

    hermes Guest

    (xposted due to small group sizes)

    Question, what are the probabilities of getting a reliable signal with
    the following circumstances:

    Main Wifi transmission point is approx. 2/3 km from house. Signal points
    downward toward nearby plaza with a 60 degree spread.

    One building between line of sight and signal that I think is a couple
    of stories short of the building where the wifi signal point emanates
    (from roof-not positive on this-how critical is line of sight)

    using primestar or similar dish antennae-home made-can put on roof of
    house pointing to same direction of signal

    using good wifi card with good reception range

    users near plaza give various reports from flaky reception to reception
    beyond plaza. one guy tells me he gets it from his house, even further
    than I am, but do not know if this is reliable report.

    Finally and most importantly, is there any way to determine if signal
    can be had using signal strength meter or other equipment, without
    setting up the dish to test it?
     
    hermes, Nov 16, 2005
    #1
    1. Advertising

  2. hermes

    hermes Guest

    Variables importance in range of signal was: Any EE experts out there

    Change of Subject for the netcops out there :)

    hermes <> wrote in news:dlft5s$7f3$1
    @odin.weihenstephan.org:

    > (xposted due to small group sizes)
    >
    > Question, what are the probabilities of getting a reliable signal with
    > the following circumstances:
    >
    > Main Wifi transmission point is approx. 2/3 km from house. Signal

    points
    > downward toward nearby plaza with a 60 degree spread.
    >
    > One building between line of sight and signal that I think is a couple
    > of stories short of the building where the wifi signal point emanates
    > (from roof-not positive on this-how critical is line of sight)
    >
    > using primestar or similar dish antennae-home made-can put on roof of
    > house pointing to same direction of signal
    >
    > using good wifi card with good reception range
    >
    > users near plaza give various reports from flaky reception to

    reception
    > beyond plaza. one guy tells me he gets it from his house, even further
    > than I am, but do not know if this is reliable report.
    >
    > Finally and most importantly, is there any way to determine if signal
    > can be had using signal strength meter or other equipment, without
    > setting up the dish to test it?
    >
     
    hermes, Nov 16, 2005
    #2
    1. Advertising

  3. On Wed, 16 Nov 2005 18:18:37 +0000 (UTC), hermes <>
    wrote:

    I got me a BSEE and I are an expert. Whatcha want?

    >(xposted due to small group sizes)


    Lousy reason. Maybe with a little effort, you can also work on an
    appropriate subject line. I decide which questions are worth
    answering by the subject line.

    >Question, what are the probabilities of getting a reliable signal with
    >the following circumstances:


    Probability? Most of the time, wireless either works or it doesn't. A
    flakey connection, that drifts in and out is not considered working. A
    good rule of thumb is a minimum 20dB fade margin for the link which
    will give about 99% reliability. (Notice I said minimum). 99% isn't
    that great as it suggests roughly 3.6 full days of outage every year.

    Reliability Fade Margin
    90% 8 dB
    99% 18 dB
    99.9% 28 dB
    99.99% 38 dB
    99.999% 48 dB

    >Main Wifi transmission point is approx. 2/3 km from house. Signal points
    >downward toward nearby plaza with a 60 degree spread.


    Lovely. Any particular reason you don't bother disclosing the details
    of your "main wi-fi transmission point"? Little details like the make
    and model, the type of coax, and the type of antenna are necessary to
    calculate the path. 60 degree spread probably means 60dB -3dB
    beamwidth. Vertical or Horizontal beamwidth? Without numbers, I
    don't wanna bother doing the calcs.

    Incidentally, if your "main wi-fi transmission point" antenna is a
    high gain omnidirectional antenna, you're in trouble. The vertical
    beamwidth of high gain omnis is quite narrow. You won't get anything
    at -30 degrees down. All the RF is going over everyone's head.

    >One building between line of sight and signal that I think is a couple
    >of stories short of the building where the wifi signal point emanates
    >(from roof-not positive on this-how critical is line of sight)


    Line of sight is critical. NLOS is science fiction. You actually
    need more than just line of sight. You need Fresnel Zone clearance at
    the midpoint of the path.

    >using primestar or similar dish antennae-home made-can put on roof of
    >house pointing to same direction of signal


    Yeah, you can use a Primstar or similar dish. Any clue what you're
    going to use for a dish feed? You can't just hang a tin can or USB
    radio at the focus and expect exemplary performance.

    >using good wifi card with good reception range


    Define "good"? Note that you can always trade reliability (fade
    margin), range, and speed. How fast do you wanna go?

    >users near plaza give various reports from flaky reception to reception
    >beyond plaza. one guy tells me he gets it from his house, even further
    >than I am, but do not know if this is reliable report.


    Any reason not to supply numbers (distances)?

    >Finally and most importantly, is there any way to determine if signal
    >can be had using signal strength meter or other equipment, without
    >setting up the dish to test it?


    Netstumbler for Windoze.
    Kismet for Linux.
    Built in diagnostics or SNMP on your unspecified access point.


    --
    Jeff Liebermann -cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558
     
    Jeff Liebermann, Nov 17, 2005
    #3
  4. hermes

    Guest

    on Wed 16 Nov 2005 10:47:15p, Jeff Liebermann
    <-cruz.ca.us> wrote in
    news::

    > On Wed, 16 Nov 2005 18:18:37 +0000 (UTC), hermes
    > <> wrote:
    >
    > I got me a BSEE and I are an expert. Whatcha want?


    How about a reply I can understand? If I could understand the
    stuff you gave me, thanks, I wouldn't need to ask you,-I'd be in
    Engynring skul myself.
    >
    >>(xposted due to small group sizes)

    >
    > Lousy reason. Maybe with a little effort, you can also work on
    > an appropriate subject line. I decide which questions are worth
    > answering by the subject line.


    Yeah, I goofed on the subject line, I admit it.
    >
    >>Question, what are the probabilities of getting a reliable
    >>signal with the following circumstances:

    >
    > Probability? Most of the time, wireless either works or it
    > doesn't. A flakey connection, that drifts in and out is not
    > considered working. A good rule of thumb is a minimum 20dB fade
    > margin for the link which will give about 99% reliability.
    > (Notice I said minimum). 99% isn't that great as it suggests
    > roughly 3.6 full days of outage every year.
    >
    > Reliability Fade Margin
    > 90% 8 dB
    > 99% 18 dB
    > 99.9% 28 dB
    > 99.99% 38 dB
    > 99.999% 48 dB
    >
    >>Main Wifi transmission point is approx. 2/3 km from house.
    >>Signal points downward toward nearby plaza with a 60 degree
    >>spread.

    >
    > Lovely. Any particular reason you don't bother disclosing the
    > details of your "main wi-fi transmission point"? Little details
    > like the make and model, the type of coax, and the type of
    > antenna are necessary to calculate the path. 60 degree spread
    > probably means 60dB -3dB beamwidth. Vertical or Horizontal
    > beamwidth? Without numbers, I don't wanna bother doing the
    > calcs.


    Cuz I don't know them and the one guy who is an exec for the
    project didn't seem too technically inclined either. I checked
    again and yipee I DO have a line of sight to the antenna, I THINK.
    There are about 5 antennas on the building, any idea what shape
    this one might be? This is a municipal wifi transmission tower
    meant for the city plaza yuppies to use their laptops. I just
    happen to have a line of sight about .6 km from the building.

    >
    > Incidentally, if your "main wi-fi transmission point" antenna is
    > a high gain omnidirectional antenna, you're in trouble. The
    > vertical beamwidth of high gain omnis is quite narrow. You
    > won't get anything at -30 degrees down. All the RF is going
    > over everyone's head.


    Two small dish antennas on roof, one tower about 6 feet high and a
    foot in oval diameter, one rather smallish rectangle antenna about
    3 feet high with a rectangular element about 2 feet by two feet.
    This is from binocular observations as the people who run this
    aren't too accessible.
    >
    >>One building between line of sight and signal that I think is a
    >>couple of stories short of the building where the wifi signal
    >>point emanates (from roof-not positive on this-how critical is
    >>line of sight)

    >
    > Line of sight is critical. NLOS is science fiction. You
    > actually need more than just line of sight. You need Fresnel
    > Zone clearance at the midpoint of the path.


    What the hell is Fresnel Zone clearance Dr. Spock? I have line of
    sight, so my guess is a good antennae will boost the signal
    enoughto get it reliably, but I am a novice, if it wasn't already
    obvious, with a very small understanding of electronics and a
    worse understanding of radio frequency stuff.
    >
    >>using primestar or similar dish antennae-home made-can put on
    >>roof of house pointing to same direction of signal

    >
    > Yeah, you can use a Primstar or similar dish. Any clue what
    > you're going to use for a dish feed? You can't just hang a tin
    > can or USB radio at the focus and expect exemplary performance.


    Yep, have instructions for building with tin can. Question, where
    can I buy a used dish for cheap?

    >
    >>using good wifi card with good reception range

    >
    > Define "good"? Note that you can always trade reliability (fade
    > margin), range, and speed. How fast do you wanna go?


    Would be happy with even 1 MB /sec as I am on dialup now.
    >
    >>users near plaza give various reports from flaky reception to
    >>reception beyond plaza. one guy tells me he gets it from his
    >>house, even further than I am, but do not know if this is
    >>reliable report.

    >
    > Any reason not to supply numbers (distances)?


    Well these reports are not really judged reliable, but most users
    are using standard laptops from about 100 yards, estimate.
    >
    >>Finally and most importantly, is there any way to determine if
    >>signal can be had using signal strength meter or other
    >>equipment, without setting up the dish to test it?

    >
    > Netstumbler for Windoze.
    > Kismet for Linux.
    > Built in diagnostics or SNMP on your unspecified access point.


    I meant without buying wifi pci cards ahead of time. What
    questions should I ask the tech people on this IF I can get to
    talk to them? Thanks for your reply.

    >
    >
     
    , Nov 18, 2005
    #4
  5. On Fri, 18 Nov 2005 03:10:07 +0000 (UTC), ""
    <> wrote:

    >on Wed 16 Nov 2005 10:47:15p, Jeff Liebermann
    ><-cruz.ca.us> wrote in
    >news::
    >
    >> On Wed, 16 Nov 2005 18:18:37 +0000 (UTC), hermes
    >> <> wrote:
    >>
    >> I got me a BSEE and I are an expert. Whatcha want?

    >
    >How about a reply I can understand? If I could understand the
    >stuff you gave me, thanks, I wouldn't need to ask you,-I'd be in
    >Engynring skul myself.


    I charge extra for intelligible answers. If there's something you
    don't understand, just ask and I'll either explain, or point you at an
    appropriate online tutorial. Kindly disclose your educational level
    and experience so I can package the responses accordingly. If you ask
    for an EE to respond, you'll get an answer at the level of an EE.

    >Cuz I don't know them and the one guy who is an exec for the
    >project didn't seem too technically inclined either.


    Guess. You'll be amazed at how close you can get. For example, the
    list of hardware you currently have can easily be guessed by looking
    at the serial number tag and disclosing the make and model. If you
    don't know the coax cable type, just read the label on the coax. The
    antenna can be roughly described by type and size.

    >I checked
    >again and yipee I DO have a line of sight to the antenna, I THINK.


    Too much smog in the way? What's the problem? Moving obstructions?

    >There are about 5 antennas on the building, any idea what shape
    >this one might be? This is a municipal wifi transmission tower
    >meant for the city plaza yuppies to use their laptops. I just
    >happen to have a line of sight about .6 km from the building.


    Post a photograph of the installation on some public web server. 5
    antennas implies sector antennas. Usually there are only 3 or 4. Five
    antennas is too much so there may be more than one service on the
    tower. Hard to tell from here. How tall are the antennas? Are they
    omnis (round tubular vertical) or panels? Just the antennas pointed
    in your direction.

    Gotta run. More later.
    (chop...)
     
    Jeff Liebermann, Nov 18, 2005
    #5
  6. On Fri, 18 Nov 2005 03:10:07 +0000 (UTC), ""
    <> wrote:

    (Blundering onward...)

    >Two small dish antennas on roof,


    Those are for the backhaul back to the ISP. Two dishes implies two
    different service providers on the tower which explains the large
    number (5) of antennas. Try to figure out which antenna is the one
    your connection is using.

    >one tower about 6 feet high and a
    >foot in oval diameter, one rather smallish rectangle antenna about
    >3 feet high with a rectangular element about 2 feet by two feet.


    2ft by 2ft sounds like a panel antenna. However, at 2.4Ghz, an
    antenna that size would have about 15dBi gain and be rather
    directional. If it's pointed downward, it's intended to "illuminate"
    a rather small area. You will have difficulties connecting to this
    panel antenna as it offers very little to the sides and none from
    behind.

    >This is from binocular observations as the people who run this
    >aren't too accessible.


    Leave a note for them taped to the door or to the equipment asking for
    them to call you. I've done this a few times and it's worked quite
    well.

    >What the hell is Fresnel Zone clearance Dr. Spock?


    You're learning, Grasshopper. Fresnel Zone clearance is the radius
    from the center line that you need in addition to line of sight to
    insure that any objects inside the Fresnel Zone do not create edge
    diffraction effects and trash the signel. At 0.6km and 2.4Ghz, it's
    about 4 meters at midpoint. Mentally draw and 8 meter diameter circle
    at the midpoint of your link. Do you have that much clearance?
    http://terabeam.com/support/calculations/fresnel-zone.php

    >I have line of
    >sight, so my guess is a good antennae will boost the signal
    >enoughto get it reliably, but I am a novice, if it wasn't already
    >obvious, with a very small understanding of electronics and a
    >worse understanding of radio frequency stuff.


    Assumption, the mother of all screwups. Yes, a good antenna will
    probably get a good connection at 0.6km if the following criteria are
    met.
    1. The central access point antenna has some RF pointed in your
    direction. This is rather dubious and the reason I want to see a
    photo of the access point antennas.
    2. There is no technology in place that restricts the distance one
    can connect.
    3. There is nothing in the Fresnel Zone to create problems.
    4. The central access point has sufficient transmit power and receive
    sensitivity. Some WISP providers intentionally reduce their tx power
    and reduce their sensitivity so that they do not overlap the coverage
    from adjacent radio systems.
    5. There is no interference from other users on the same channels.
    6. Your end has a sufficiently high gain antenna to yield a useable
    signal level.

    In this case, it's highly likely that it will work if #1 is met. At
    0.6km, I like to run the numbers first to insure that it will work on
    paper before you make the attempt. See below.

    >Yep, have instructions for building with tin can. Question, where
    >can I buy a used dish for cheap?


    I'm partial to the Pacific Wireless dish antennas. They're the ones
    that look like a wire barbeque grill. Solid dish antennas are better,
    but far more expensive.
    http://www.pacwireless.com/products/directional.shtml
    $40 to $70 each depending on gain (15dBi, 19dBi, and 24dBi).

    >Would be happy with even 1 MB /sec as I am on dialup now.


    Nobody is happy with 1Mbit/sec. However, if this is a public
    municipal hot spot, they probably limit the connection rate to either
    5.5Mbits/sec or 11Mbits/sec for maximum compatibility with commodity
    802.11b hardware. Assuming you're the only user, that will give you
    perhaps 2Mbits/sec or 5Mbits/sec thruput. If the signal is weak, some
    hot spots do not allow 1 and 2 mbit/sec connections because it hogs
    too much air time.

    >>>Finally and most importantly, is there any way to determine if
    >>>signal can be had using signal strength meter or other
    >>>equipment, without setting up the dish to test it?

    >>
    >> Netstumbler for Windoze.
    >> Kismet for Linux.
    >> Built in diagnostics or SNMP on your unspecified access point.

    >
    >I meant without buying wifi pci cards ahead of time.


    Don't buy a wireless PCI card. Unless you can see the central access
    point from wherever you plant your computah and can attach an antenna
    fairly close to the computah, the coaxial cable losses will be
    excessive. If the dish, panel, or tin can antenna is going on the
    roof, your wireless client will need to be nearby to reduce the coax
    losses. You may need to do some waterproofing and cabling. You can
    also possibly use a USB radio if your total cable lengths are less
    than 3 meters or your purchase overpriced USB line extenders.

    I don't wanna recommend any hardware until I determine how much do it
    thyself you are willing (and able) to do. If none, I suggest an
    integrated wireless client such as:
    | http://tranzeo.com/index.php?section_id=40&sub_section_id=41&sub_sub_section_id=92
    The bottom of the line 15dBi may not be enough antenna gain to do the
    job. It really depends on how much of the central access point signal
    is pointed your direction.

    Ummm... what country are you in? Regulatory differences have a big
    effect on specs such as maximum allowed xmit power.

    >What
    >questions should I ask the tech people on this IF I can get to
    >talk to them? Thanks for your reply.


    That's a good question. Ask them:
    1. Which antenna on the tower is the one pointed in your direction?
    2. How much gain does the antenna have? How much downtilt in
    degrees? Make an model of antenna would be nice.
    3. How much coax cable loss is between the antenna and the radio.
    4. What type of radio and approximately how much transmit power
    (milliwatts or dBm is fine). Make and model would be nice. I can
    guess the receiver sensitivity.
    5. Do they support 802.11g speeds? If not, what are the allowed
    connection speeds?

    I'll do a dry run on the calcs to show you what I mean. The number
    are guesses based on what you've already supplied. The central
    antenna is apparently pointed downward rather than at the horizon
    which means you won't have much gain in your direction. That will be
    the major headache. I'll assume clear line of sight including the
    Fresnel Zone. I'll also assume a 5.5Mbit/sec connection. The goal of
    this exercise is to get more than 20dB fade margin.

    Pluging the quesswork into:
    http://www.terabeam.com/support/calculations/som.php
    TX power = +15dBm
    TX coax loss = 4dB (3ft LMR-240 plus a mess of connectors)
    TX ant gain = 3dB (due to being off the side of the main pattern)
    Distance = 0.6km (0.37 miles)
    RX ant gain = +24dBi (biggest dish available)
    RX coax loss = 4dB (assumes radio on roof)
    RX sens = -85dBm (at 5.5Mbits/sec CCK)
    This yields fade margin of 23.4dB which is fine. A smaller 19dBi dish
    will also work with 20.4dB fade margin. However, a 15dBi dish or
    panel will NOT work.

    The obvious limiting factor on the above calculations is the antenna
    gain and directionality of the access point panel antenna. My guesses
    are totally arbitrary and are probably wrong. It may be better or it
    may be much worse depending on which direction the antenna is pointed.

    Incidentally, the Primestar dish idea will work, but you will need to
    do some rather complex calculations, modeling, and testing to get
    anything useful. Low gain (<10dBi) antennas are fairly easy. High
    gain antennas are not.



    --
    Jeff Liebermann -cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558
     
    Jeff Liebermann, Nov 18, 2005
    #6
  7. hermes

    John Navas Guest

    [POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

    In <dljgmb$38t$> on Fri, 18 Nov 2005 03:10:07 +0000
    (UTC), "" <> wrote:

    >What the hell is Fresnel Zone clearance Dr. Spock?


    As always, "Google is your friend!"
    <http://www.google.com/search?q=Fresnel%20Zone%20clearance>

    >... Question, where
    >can I buy a used dish for cheap?


    Housewares dept.

    --
    Best regards, FAQ FOR CINGULAR WIRELESS
    John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>
    MY HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
    <http://navasgrp.home.att.net/#Cingular>
     
    John Navas, Nov 18, 2005
    #7
  8. hermes

    John Navas Guest

    [POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

    In <> on Fri, 18 Nov 2005 03:55:39
    GMT, Jeff Liebermann <-cruz.ca.us> wrote:

    >Post a photograph of the installation on some public web server. ...


    e.g., <http://commons.wikimedia.org/>

    --
    Best regards, FAQ FOR CINGULAR WIRELESS
    John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>
    MY HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
    <http://navasgrp.home.att.net/#Cingular>
     
    John Navas, Nov 18, 2005
    #8
  9. hermes

    hermes Guest

    Jeff Liebermann <-cruz.ca.us> wrote in
    news:eek::

    >



    Thank you very much Dr. Spock. I have some homework to do, so please
    give me a few days; hope you are around then. At least I have an idea of
    what I am up against now. Main thing is to find which antenna and
    whether I can grab a slice of the signal or not (degree of tilt?).

    Will report back when/if I can get some better information (can tell you
    are indeed and expert-unlike so many pseudo experts out there).
     
    hermes, Nov 18, 2005
    #9
  10. hermes

    hermes Guest

    Dr. Spoke, today I found out the connections are limited to 512KB/second
    and that they have NO wep key-no security, so I would have to set up a
    VPN, whatever the hell that is (have a rough idea). So, sounds like it
    is not worth the effort; wish I had found this out sooner. :-( Thanks
    again for the tutorial on wifi transmission/reception.

    Jeff Liebermann <-cruz.ca.us> wrote in
    news:eek::

    > On Fri, 18 Nov 2005 03:10:07 +0000 (UTC), ""
    > <> wrote:
    >
    > (Blundering onward...)
    >
    >>Two small dish antennas on roof,

    >
    > Those are for the backhaul back to the ISP. Two dishes implies two
    > different service providers on the tower which explains the large
    > number (5) of antennas. Try to figure out which antenna is the one
    > your connection is using.
    >

    <snip>
     
    hermes, Nov 22, 2005
    #10
  11. On Tue, 22 Nov 2005 00:40:56 +0000 (UTC), hermes <>
    wrote:

    >Dr. Spoke,


    Spoke? I think you mean Spock.

    >today I found out the connections are limited to 512KB/second


    Well, that's the transfer speed limit as established by bandwidth
    managment or throttling. It has nothing to do with the maximum
    connection speed. However, at that low a speed, my guess is that they
    allow any of the 802.11b speeds, but none of the 802.11g speed.

    >and that they have NO wep key-no security, so I would have to set up a
    >VPN, whatever the hell that is (have a rough idea).


    VPN's are a good thing so evil people like me don't sniff your
    traffic, extract your logins and passwords, and provide you with
    excessive entertainment while pillaging your bank account and
    borrowing your identity. If I can't get your logins and passwords,
    I'll settle for a few juicy email messages which can later be used for
    blackmail.

    >So, sounds like it
    >is not worth the effort; wish I had found this out sooner. :-( Thanks
    >again for the tutorial on wifi transmission/reception.


    What do you mean not worth the effort? 512Kbytes per second is not
    the fastest broadband available, but is still 15 times faster than a
    dialup modem. With a VPN, you don't need WEP or WPA to secure your
    connection. The VPN will provide the necessary encryption,
    authentication, and security.


    --
    Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
    831.336.2558 voice
    http://www.LearnByDestroying.com AE6KS
    http://802.11junk.com Skype: JeffLiebermann
    -cruz.ca.us
     
    Jeff Liebermann, Nov 22, 2005
    #11
  12. hermes wrote:

    > Dr. Spoke,


    "Dr" Spock is the baby doctor... :)

    > today I found out the connections are limited to 512KB/second
    > and that they have NO wep key-no security, so I would have to set up a
    > VPN, whatever the hell that is (have a rough idea). So, sounds like it
    > is not worth the effort; wish I had found this out sooner. :-( Thanks
    > again for the tutorial on wifi transmission/reception.


    I'd sell body or soul (whichever's worth less) for a 512KB/second link.
    Really, is that KB? That's about 5Mb/s which is nothing to cry about. I'd
    only sell my firstborn for 512Kb/s (except I don't have a firstborn). It's
    not that difficult to set up a VPN - googling for "commercial vpn service"
    shows plenty of providers. iPIG is even free (haven't tried it).
    --
    derek
     
    Derek Broughton, Nov 22, 2005
    #12
  13. hermes

    John Navas Guest

    [POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

    In <dltpek$k08$> on Tue, 22 Nov 2005 00:40:56 +0000
    (UTC), hermes <> wrote:

    >... they have NO wep key-no security, so I would have to set up a
    >VPN, whatever the hell that is (have a rough idea). ...


    http://www.hotspotvpn.com/ (commercial)
    http://www.iopus.com/ (free)

    --
    Best regards, FAQ FOR CINGULAR WIRELESS
    John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>
     
    John Navas, Nov 22, 2005
    #13
  14. hermes

    hermes Guest

    Jeff Liebermann <-cruz.ca.us> wrote in
    news::

    > On Tue, 22 Nov 2005 00:40:56 +0000 (UTC), hermes <>
    > wrote:
    >
    >>Dr. Spoke,

    >
    > Spoke? I think you mean Spock.


    Sorry, oh zen master, my typing skills need improvement.

    >
    >>today I found out the connections are limited to 512KB/second

    >
    > Well, that's the transfer speed limit as established by bandwidth
    > managment or throttling. It has nothing to do with the maximum
    > connection speed. However, at that low a speed, my guess is that they
    > allow any of the 802.11b speeds, but none of the 802.11g speed.


    Sounded like throttling. "connection limited to 512KB/sec per user"
    (from memory) Can you tell I am ignorant in this subject yet? :). They
    specifically say they support 802.11g but the connections are throttled
    to that 512KB/s limit per user or is it kb/s? I took that to mean point
    5 megabytes per second, or am I wrong? Still as you point out MUCH
    faster than dialup and it's FREE.

    >
    >>and that they have NO wep key-no security, so I would have to set up a
    >>VPN, whatever the hell that is (have a rough idea).

    >
    > VPN's are a good thing so evil people like me don't sniff your
    > traffic, extract your logins and passwords, and provide you with
    > excessive entertainment while pillaging your bank account and
    > borrowing your identity. If I can't get your logins and passwords,
    > I'll settle for a few juicy email messages which can later be used for
    > blackmail.


    I am using TOR now which I have rightly or wrongly been told can offer a
    degree of protection against sniffing, but not sure on what degree yet.

    >
    >>So, sounds like it
    >>is not worth the effort; wish I had found this out sooner. :-( Thanks
    >>again for the tutorial on wifi transmission/reception.

    >
    > What do you mean not worth the effort? 512Kbytes per second is not
    > the fastest broadband available, but is still 15 times faster than a
    > dialup modem. With a VPN, you don't need WEP or WPA to secure your
    > connection. The VPN will provide the necessary encryption,
    > authentication, and security.


    Thanks for the encouragement oh zen master, I am looking at making my
    own wifi antenna now, but per your earlier admonitions, I still do not
    have the data yet on the degree of tilt, nor which antenna it is.
    Hopefully I will be able to get this information soon. I do not have a
    good enough camera to post a picture, best I could do is post a diagram
    after I sketch it out. Assuming it is the panel antenna you said it
    might be, the only information I have is that the sweep is 60 degrees
    and I am having to guess from long distances if I can catch enough
    signal from where I am. 60 degrees but relative to what? And can I catch
    much signal from the side?

    I am going to buy a pcmcia wifi card for my win95 soon to be win98
    presario laptop (P150MHZ). I looked at your recommendation from another
    of your posts for the SMC2532W-B card, but it requires win98SE, was
    only planning for win98. I took a look at your recommendation for the
    hardware comparison tests at seattle wireless. Can you recommend a 200mw
    card that will work well with win98, that I might be able to pick up at
    a reasonable price? Something that will work on more current platforms
    as well, so when I get a new laptop I can use it also.
    Then I will build my own antenna and just test it on
    the laptop with pcmcia card connected directly to antenna.

    Thinking of trying the coffee can home made approach, do not want to
    invest too much just to see if I can get it working. Checking on finding
    prices/sources for a dish antenna, but that might be harder to setup?

    Thanks very much for your kind assistance.

    >
    >
     
    hermes, Nov 22, 2005
    #14
  15. hermes

    hermes Guest

    Derek Broughton <> wrote in
    news::

    > hermes wrote:
    >
    >> Dr. Spoke,

    >
    > "Dr" Spock is the baby doctor... :)


    Thanks to you AND Dr. Spock for the replies.
    >
    >> today I found out the connections are limited to 512KB/second
    >> and that they have NO wep key-no security, so I would have to set up
    >> a VPN, whatever the hell that is (have a rough idea). So, sounds like
    >> it is not worth the effort; wish I had found this out sooner. :-(
    >> Thanks again for the tutorial on wifi transmission/reception.

    >
    > I'd sell body or soul (whichever's worth less) for a 512KB/second
    > link. Really, is that KB? That's about 5Mb/s which is nothing to cry
    > about. I'd only sell my firstborn for 512Kb/s (except I don't have a
    > firstborn). It's not that difficult to set up a VPN - googling for
    > "commercial vpn service" shows plenty of providers. iPIG is even free
    > (haven't tried it).


    ok, most I KNOW is bits are smaller than bytes. I thought 512KB
    translated to point 5MB/sec which is slow by high speed connections but
    still much faster than what I've got?

    Trying to figure out if I can get the damn thing working FIRST. Will
    worry about security after it is up. Using Tor now which I guess offers
    some amount of encryption security. I find it impossible to keep up with
    all this stuff, so VPN will have to wait for now.
     
    hermes, Nov 22, 2005
    #15
  16. hermes

    Ryan Case Guest

    hermes wrote:

    > Derek Broughton <> wrote in
    > news::
    >
    >
    >>hermes wrote:
    >>
    >>
    >>>Dr. Spoke,

    >>
    >>"Dr" Spock is the baby doctor... :)

    >
    >
    > Thanks to you AND Dr. Spock for the replies.
    >
    >>>today I found out the connections are limited to 512KB/second
    >>>and that they have NO wep key-no security, so I would have to set up
    >>>a VPN, whatever the hell that is (have a rough idea). So, sounds like
    >>>it is not worth the effort; wish I had found this out sooner. :-(
    >>>Thanks again for the tutorial on wifi transmission/reception.

    >>
    >>I'd sell body or soul (whichever's worth less) for a 512KB/second
    >>link. Really, is that KB? That's about 5Mb/s which is nothing to cry
    >>about. I'd only sell my firstborn for 512Kb/s (except I don't have a
    >>firstborn). It's not that difficult to set up a VPN - googling for
    >>"commercial vpn service" shows plenty of providers. iPIG is even free
    >>(haven't tried it).

    >
    >
    > ok, most I KNOW is bits are smaller than bytes. I thought 512KB
    > translated to point 5MB/sec which is slow by high speed connections but
    > still much faster than what I've got?
    >
    > Trying to figure out if I can get the damn thing working FIRST. Will
    > worry about security after it is up. Using Tor now which I guess offers
    > some amount of encryption security. I find it impossible to keep up with
    > all this stuff, so VPN will have to wait for now.
    >
    >


    I think what is throwing you off is the abbreviations. Kb is Kilobit, or
    roughly 1k bits. KB is Kilobyte or roughly 1k bytes. A byte is made up
    of 8 bits. Mb is Megabit or roughly 1 million bits, and MB is Megabyte
    or roughly 1 million bytes. Big Big difference between 500KB/s and 500Kb/s.
     
    Ryan Case, Nov 22, 2005
    #16
  17. On Tue, 22 Nov 2005 21:51:29 +0000 (UTC), hermes <>
    wrote:

    >Sorry, oh zen master, my typing skills need improvement.


    I forgive you but Leonard Nemoy might not. I are not Spoke.

    >Sounded like throttling. "connection limited to 512KB/sec per user"
    >(from memory)


    It's probably throttling down to 512Kbits/sec.

    >Can you tell I am ignorant in this subject yet? :).


    Yeah, but you're learning, slowly. You only have about 200 buzzwords
    and acronyms to memorize. Then you'll be a master of technobabble
    (like me).

    >They
    >specifically say they support 802.11g but the connections are throttled
    >to that 512KB/s limit per user or is it kb/s?


    It's probably 512Kbits/sec per user. The convention is to us the
    lower case "b" to mean bits, while the upper case "B" means Bytes. Do
    you recall if they said bits or bytes? They MIGHT give each user
    5Mbits/sec which would require about a 12Mbit/sec 802.11g connection.
    If they support 802.11g and not just 802.11b, that might just be the
    case. Either way, it's worth the effort. Even 512Kbits/sec is 15
    times faster than dialup.

    >I took that to mean point
    >5 megabytes per second, or am I wrong? Still as you point out MUCH
    >faster than dialup and it's FREE.


    I can't tell from her. Drop some names and locations and I'll see
    what I can excavate with Google. Also, there's no such thing as a
    free lunch. You'll have to do some construction, buy some hardware,
    and lots of tinkering to make this work. The limiting factor is the
    central access point type, antenna system, and line of sight. Without
    knowing anything about those, I can only guess.

    >I am using TOR now which I have rightly or wrongly been told can offer a
    >degree of protection against sniffing, but not sure on what degree yet.


    TOR is good stuff:
    http://tor.eff.org
    I haven't tried it myself but I have customers and friends that use it
    to prevent sniffing. It creates an anonymous encrypted VPN tunnel to
    their servers. It also shuffles the data around making traffic
    analysis difficult. The catch is that it uses other TOR users to
    route the traffic. That means your bandwidth is limited by what the
    other users can handle. Often, there are bottlenecks. It works great
    for dialup, mediocre for low speed DSL, and absolutely sucks for
    higher speed DSL and cable modems.

    >Thanks for the encouragement oh zen master,


    One must suffer before enlightenment. Such is the way of wireless.

    >I am looking at making my
    >own wifi antenna now, but per your earlier admonitions, I still do not
    >have the data yet on the degree of tilt, nor which antenna it is.


    Take a photo and post it somewhere (not to the newsgroup). Low gain
    (<10dBi) antennas are easily built. A coffee can, biquad, or panel
    (patch) antenna can be easily built. Higher gain antennas are more
    difficult and critical without proper test equipment. I'm partial to
    biquads. Links if you want them.

    >Hopefully I will be able to get this information soon. I do not have a
    >good enough camera to post a picture, best I could do is post a diagram
    >after I sketch it out. Assuming it is the panel antenna you said it
    >might be, the only information I have is that the sweep is 60 degrees
    >and I am having to guess from long distances if I can catch enough
    >signal from where I am. 60 degrees but relative to what? And can I catch
    >much signal from the side?


    Also, is the 60 degrees the horizontal or vertical beamwidth? A
    picture is worth a 1000 guesses. In general, you will be able to get
    some signal somewhat off the side of the 60 degree beamwidth. That 60
    degrees is plus or minus 30 degress from the center axis at the -3dB
    (half power) points. Signal levels start to drop rapidly past the
    -3dB points but do not disappear completely. If you're close enough,
    and have a high enough gain antenna, it will probably work.

    >I am going to buy a pcmcia wifi card for my win95 soon to be win98
    >presario laptop (P150MHZ).


    Good enough. My previous laptop was a P133 junker (Compaq 1620?)
    which I suspect is similar. You won't find any PCMCIA drivers that
    work reliably on Windoze 95. Go to Win98SE or WinME and the selection
    improves.

    >I looked at your recommendation from another
    >of your posts for the SMC2532W-B card, but it requires win98SE, was
    >only planning for win98.


    Get Win98 second edition. The original Win98 is worthless. I prefer
    WinME but that requires considerable tweaking to disarm some stupid
    features and get it to work reliably. I got stuck with a Win98 first
    edition laptop and tried to run Netstumbler on it using an Orinoco
    silver card. It would hang constantly. Upgraded the laptop to WinME
    and everything is just fine.

    >I took a look at your recommendation for the
    >hardware comparison tests at seattle wireless. Can you recommend a 200mw
    >card that will work well with win98, that I might be able to pick up at
    >a reasonable price?


    You'll notice that I don't make hardware recommendations for stuff
    that I haven't played with. I get far too many suprises. The Senao
    based 802.11b cards seem to work well for me:
    http://www.seattlewireless.net/index.cgi/SenaoCard
    I know little about the SMC card.

    >Something that will work on more current platforms
    >as well, so when I get a new laptop I can use it also.
    > Then I will build my own antenna and just test it on
    >the laptop with pcmcia card connected directly to antenna.


    In that case, you'll need something that has an external antenna
    connector.

    >Thinking of trying the coffee can home made approach, do not want to
    >invest too much just to see if I can get it working. Checking on finding
    >prices/sources for a dish antenna, but that might be harder to setup?


    Dish antennas are tricky to aim. However, at 600 meters range, dish
    alignment is trivial. Build the coffee can or just hang the laptop
    out the window for initial testing. If it sorta works, a bigger
    antenna will only work better.

    >Thanks very much for your kind assistance.


    I only give one kind of assistance.

    --
    Jeff Liebermann -cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558
     
    Jeff Liebermann, Nov 23, 2005
    #17
  18. hermes wrote:

    > ok, most I KNOW is bits are smaller than bytes. I thought 512KB
    > translated to point 5MB/sec which is slow by high speed connections but
    > still much faster than what I've got?


    Exactly, but there are still people out there getting 1 or 2Mbps on a DSL
    line - much less than your number. otoh, on my satellite link, I
    sometimes only get 500Kbps (bits), so your speed - with the lower latency
    of a terrestrial connection - would be an improvement for me.

    Network speeds are usually (but definitely not always) given in bits per
    second, so 1/2 Mbps is on the slow end for a broadband connection - but 1/2
    MBps (Byte) is about 5Mbps, which is not as fast as some cable modems but
    definitely not too shabby.
    --
    derek
     
    Derek Broughton, Nov 23, 2005
    #18
  19. hermes

    hermes Guest

    Thanks for the clarification. One reason I am so slow in these
    areas is math was not exactly my best subject, haha. Will post to
    group later on success/failure of this whole dubious venture.

    on Wed 23 Nov 2005 08:17:57a, Derek Broughton
    <> wrote in
    news::

    > hermes wrote:
    >
    >> ok, most I KNOW is bits are smaller than bytes. I thought 512KB
    >> translated to point 5MB/sec which is slow by high speed
    >> connections but still much faster than what I've got?

    >
    > Exactly, but there are still people out there getting 1 or 2Mbps
    > on a DSL line - much less than your number. otoh, on my
    > satellite link, I sometimes only get 500Kbps (bits), so your
    > speed - with the lower latency of a terrestrial connection -
    > would be an improvement for me.
    >
    > Network speeds are usually (but definitely not always) given in
    > bits per second, so 1/2 Mbps is on the slow end for a broadband
    > connection - but 1/2 MBps (Byte) is about 5Mbps, which is not as
    > fast as some cable modems but definitely not too shabby.
     
    hermes, Nov 23, 2005
    #19
  20. Wireless network is always difficult, and is not reliable. But if you dont
    have specially programs to use over there, I would have made it, with two
    accesspoints and external antennas. I have done that before , and it was 5
    km.

    "hermes" <> skrev i melding
    news:dlft5s$7f3$...
    > (xposted due to small group sizes)
    >
    > Question, what are the probabilities of getting a reliable signal with
    > the following circumstances:
    >
    > Main Wifi transmission point is approx. 2/3 km from house. Signal points
    > downward toward nearby plaza with a 60 degree spread.
    >
    > One building between line of sight and signal that I think is a couple
    > of stories short of the building where the wifi signal point emanates
    > (from roof-not positive on this-how critical is line of sight)
    >
    > using primestar or similar dish antennae-home made-can put on roof of
    > house pointing to same direction of signal
    >
    > using good wifi card with good reception range
    >
    > users near plaza give various reports from flaky reception to reception
    > beyond plaza. one guy tells me he gets it from his house, even further
    > than I am, but do not know if this is reliable report.
    >
    > Finally and most importantly, is there any way to determine if signal
    > can be had using signal strength meter or other equipment, without
    > setting up the dish to test it?
     
    Tom Eirik Jensen, Nov 25, 2005
    #20
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Denise

    Any HP experts out there?

    Denise, Jan 24, 2004, in forum: Computer Support
    Replies:
    14
    Views:
    924
    Jan Ras
    Jan 27, 2004
  2. Sens Fan Happy In Ohio

    Any DOS Experts Out There??

    Sens Fan Happy In Ohio, May 2, 2004, in forum: Computer Support
    Replies:
    11
    Views:
    774
    Toolman Tim
    May 3, 2004
  3. CSB

    Any AOL AIM experts out there?

    CSB, Jan 5, 2005, in forum: Computer Support
    Replies:
    5
    Views:
    448
    Alexander Rogge
    Jan 5, 2005
  4. Toolman Tim

    Another screwup--any Dell experts out there??

    Toolman Tim, Sep 15, 2005, in forum: Computer Support
    Replies:
    3
    Views:
    1,915
    Toolman Tim
    Sep 16, 2005
  5. Replies:
    7
    Views:
    362
    Paul Repacholi
    Feb 9, 2007
Loading...

Share This Page