Straightforward out-of-the-box solution for extending WiFi range

Discussion in 'Wireless Internet' started by Danny D'Amico, Dec 13, 2013.

  1. Danny D'Amico

    miso Guest

    Most good notebooks have at least two antennas. As far as I know, Apple
    uses one on the back where the logo is show. My Dell is metal cased, but
    has plastic on the side, so I guess that is where they hid the antennas.

    Lenovo makes good stuff, but then again, Dell has that refurb store. ;-)
     
    miso, Dec 23, 2013
    #81
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  2. Danny D'Amico

    miso Guest

    If you mean Netstumber, that is an active wifi sniffer. Not particularly
    useful in my opinion.

    Most of the Alfa usb dongles work with kismet I have a AWUS051NH. It is
    a bit deaf being dual band and all. The 2.4G Tube-u really works well
    with kismet.

    You need a wifi chipset/driver that has monitor mode.
     
    miso, Dec 23, 2013
    #82
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  3. Danny D'Amico

    DevilsPGD Guest

    If the underlying networks are bridged, this is a supported
    configuration and it allows client machines to move between the access
    points seamlessly.

    If the networks are not bridged, this will cause IP conflicts and other
    problems.
     
    DevilsPGD, Dec 24, 2013
    #83
  4. I call it dueling routers. ^_^

    TDD
     
    The Daring Dufas, Dec 24, 2013
    #84
  5. Danny D'Amico

    krw Guest

    I have five but they just make sawdust.
     
    krw, Dec 24, 2013
    #85
  6. Or the dualism of routers. ^_^

    TDD
     
    The Daring Dufas, Dec 24, 2013
    #86
  7. I think, if it's 802.11n, it must have (at least) two antennas.
    Right?
     
    Danny D'Amico, Dec 24, 2013
    #87
  8. Actually, all the Ubiquiti radios I have (bullet, nanobridge, rocket)
    are radios and routers at the same time.

    While they all have only one Ethernet port, they can all serve DHCP,
    for example, over that one wire. They can do NAT. They can bet set
    for static IP addresses. They can be set into Bridge mode, or
    Router mode, or Access Point mode, etc. They all have a web
    interface for easy setup, etc.

    Just like your common home broadband router.

    Of course, most home broadband routers also have at least a 4 port
    switch on the back, which these routers do not have. So, I do agree
    that you don't generally use these radios as routers, per se.
    You have a point there, in that everyone should use the weakest
    signal possible to accomplish the intended goal.

    A house is only so big, so, that's why most home broadband routers
    are limited to around 15 to 18dBm with a 3 to 6 dBi antenna.

    The more I look at the Ubiquiti access points, the more I like
    *them* though, in favor of seting up another router. To your point,
    these UniFy access points are *not* routers! I agree. They are
    just access points that you connect to the switch at the back of
    the home broadband router.
    I understand. It's common courtesy to use the minimum power you need.
    Just like international diplomacy. :)
     
    Danny D'Amico, Dec 24, 2013
    #88
  9. I am always confused if it's raw "monitor" or "promiscuous" mode that
    is required, but, I do realize that you need a chipset which allows you
    to show packets which aren't meant for you.

    In the past, on the PC, I had used NetStumbler and NetCrumbler, the
    difference being NetCrumbler allowed you to actually connect, while
    NetStumbler expressly denied that capability.

    On Android, when I search for NetStumbler, I only see "Meraki
    WiFi Stumbler", which I don't think is the same thing.

    I don't know if the Ubuiquiti Bullet M2, Nanobridge M2, or Rocket
    M2 that I have will allow "monitor" mode, but, I would suspect
    they do.

    That means I only need to find a Netstumbler/crumbler equivalent
    for Linux to test it out on my Lenovo W510 laptop. I think that
    might be kismet, wifi-radar or iwscanner ...
     
    Danny D'Amico, Dec 24, 2013
    #89
  10. I haven't tried that yet. :)

    I'm still just practicing by logging into my own home broadband
    router.

    As noted, the antenna and receiver sensitivity are the limiting
    factors; not the transmit power.
    Oh oh... I have those cheap 70W ones. What's the problem if
    they're not a pure sine wave?
     
    Danny D'Amico, Dec 24, 2013
    #90
  11. Danny D'Amico, Dec 24, 2013
    #91
  12. 1. The "modified sine wave" variety tend to generate high power RFI
    (both conducted and radiated) which your receiver will not appreciate.

    2. The power that its NOT part of the fundamental sine wave, has to
    go somewhere. For example, the worst case is if the inverter belches
    a square wave, where 1/3 of the power is in harmonics of the
    fundamental sine wave. That power has to go somewhere. It can be
    radiated, which is unlikely at 60 Hz. Since the radio power supply
    usually has a low pass filter at the input, it can be dissipated in
    the filter, or it can be reflected back to the inverter, which usually
    fails to appreciate the added voltage or current (depending on phase).

    3. Inverters tend to have switching spikes on the output. They
    create RFI, but if large enough, can blow up downstream electronics.

    How close to a sine wave does the output need to be? Difficult to
    tell. It depends on the load. Some wall-wart style switchers
    tolerate almost anything, while others blow up with little or no
    provocation.

    Personally, I like to run everything on 12V DC (actually 11-15VDC).
    While that has its own collection of horrors, such as voltage spike on
    the vehicle battery line when starting the engine, having a built in
    UPS makes it worthwhile.
     
    Jeff Liebermann, Dec 25, 2013
    #92
  13. Everyone seems to have different definitions of what constitutes
    "carrier class" or "professional" wireless hardware. For me, it's
    quite simple. Will it do SNMP and can it be monitored and managed
    with 3rd party tools?
    <http://wiki.ubnt.com/SNMP_and_MRTG_Monitoring>
    I think you'll find that SNMP support will make a good dividing line
    between consumer and pro. The average home user doesn't need SNMP
    even if it's provided. I need it to keep a mess of access points and
    routers alive and provide reports and pretty graphs to keep the
    customer happy. ISP's need SNMP to allow a diverse collection of
    dissimilar hardware to be monitored and managed with a single software
    tool:
    <http://www.techrepublic.com/blog/five-apps/five-free-network-monitoring-tools/>
     
    Jeff Liebermann, Dec 25, 2013
    #93
  14. There's nothing wrong with using the same SSID on multiple access
    points. It's a good idea to have put each AP on a different RF
    channel, so that they don't interfere with each other.

    The problem is that most users expect seamless roaming between access
    points, and that's not going to happen. Instead, the wireless client
    initially picks the strongest/best signal, and connects to that access
    point. If the signal level changes, like you're walking around the
    house, the wireless client continues to use the first access point,
    even though a strong/better signal is available. You have to manually
    disconnect from the first access point, before the client radio will
    try to find a better connection. By using different SSID's, you can
    manually select which of your access points to use. However, if you
    have a large system, with dozens of access points, individual SSID's
    is not particularly user friendly.

    If you really want seamless roaming between access points, you'll need
    a device that supports 802.11r and layer 3 (IP) roaming, which
    maintain the same IP address and connection as you switch between
    AP's:
    <https://meraki.cisco.com/technologies/seamless-mobility>
    For Ubiquity, you'll need a Zero Handoff Roaming (UniFi 3.0) device:
    <http://windowspbx.blogspot.com/2013/04/ubiquiti-unifi-now-supports-zero.html>
    <http://dl.ubnt.com/datasheets/unifi/UBNT_DS_Zero_Handoff_Roaming.pdf>
    <http://community.ubnt.com/t5/UniFi-...tions/UniFi-What-is-Zero-Handoff/ta-p/412719>
     
    Jeff Liebermann, Dec 25, 2013
    #94
  15. Everything I write is interesting. Sometimes, it's even accurate.
    <http://www.intel.com/support/wireless/wlan/sb/cs-015906.htm>
    Fat chance. That's the way it should work. Instead, what happens is
    that the client will remain connected to the initial access point, no
    matter how weak or disgusting a signal it offers. Even if turn off
    the client device, it will try to reconnect to the same initial access
    point, even if there's a stronger/better signal with the same SSID
    evailable. Even if you intentionally disconnect, the client will
    retain the MAC address of the initial access point. When you try to
    reconnect, it will try that MAC address first.

    Intel seems to have gotten the clue and offers a setting as to how
    "aggressive" the client will act in retaining a connection:
    <http://www.intel.com/support/wireless/wlan/sb/CS-030101.htm>
    It's not a total solution, but does work rather well on my various
    laptops.
     
    Jeff Liebermann, Dec 25, 2013
    #95
  16. It was added in UniFi 3.x. I'm too lazy to lookup the current
    version.

    If you want to see what can be done with seamless roaming, try the
    EduRoam system.
    <https://www.eduroam.us/introduction>
    <http://its.ucsc.edu/wireless-secure/using-eduroam.html>
    I can login and authenticate at UCSC, put my laptop in standby, go for
    a long drive around Monterey Bay, and reconnect at CSUMB, retaining
    both the local DHCP IP address and any remote connections (if their
    servers don't time out). It's really impressive.
     
    Jeff Liebermann, Dec 25, 2013
    #96
  17. Well, it's time you tried it. Something like this, for your link to
    your WISP, is what you should eventually get:
    <http://community.ubnt.com/t5/airMax-General-Discussion/Signal-Noise-history/td-p/48143>

    Basic Ubiquiti instructions:
    <http://wiki.ubnt.com/SNMP_and_MRTG_Monitoring>
    Do the first step to enable SNMP. Also, download ALL the MIB files
    listed at the bottom of the page. You'll need them later.

    SNMP "Community" is a lousy name for password. Depending on your
    product, there are usually two community names. One for read-only
    access. The other for write access. Use the read-only for now.

    There's also PRTG if you want graphs:
    <http://www.ireasoning.com/mibbrowser.shtml>
    <http://www.paessler.com/prtg/screenshots>
    <http://www.paessler.com/manuals/prtg/quick_start_guide.htm>
    There are also Android and iPhone versions of the software.

    There are others, but I think PRTG is the easiest MIB browser to get
    started.
    Yep. The limiting factor is that to do SNMP properly, one needs a
    dedicated "management workstation" also known as a server or data
    dumpster. SNMP can potentially generate plenty of data and traffic.
    Most home users don't want to deal with a dedicated data collector,
    even though it can be done on a Raspberry Pi, a media server, or some
    NAS boxes.
    <http://www.supagusti.tk/computer/raspberrypi/160-installing-mrtg-on-your-pi>
    <http://n00blab.com/cacti-pi/>
    However, such servers are mandatory for running a WISP.
     
    Jeff Liebermann, Dec 25, 2013
    #97
  18. Danny D'Amico

    Char Jackson Guest

    If they aren't bridged, they're probably routed. Then, if each segment has a
    unique IP address space, it should just work. But if each segment has the
    same IP address space, the main problem won't be IP conflicts but rather IP
    routing issues. The IP stack will treat it as Layer 2 but it needs to be
    treated as Layer 3. I assume that's the "other problems" mentioned above.
     
    Char Jackson, Dec 26, 2013
    #98
  19. Danny D'Amico

    krw Guest

    Nah, it's too hard to clean the routers after. The brains and guts
    are too small to be a problem but the blood gets everywhere.
     
    krw, Dec 26, 2013
    #99
  20. Ummm, not exactly. +36 dBm (4 watts) EIRP is the limit with an omni
    directional antenna. For point to point, the FCC allows more tx
    power. For point to point, for every 1 dB of directional antenna gain
    over +6 dBi, the transmit power need only be reduced 1/3 dB. Rather
    than do the math, I just remember that for a 24 dBi antenna, the
    maximum tx power is 24 dBm (0.25 watts) with an EIRP of:
    24 dBm + 24 dBi = 48 dBm (63 watts).

    More:
    <http://www.lns.com/papers/part15/Regulations_Affecting_802_11.pdf>
     
    Jeff Liebermann, Dec 26, 2013
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