Internal vs external 802.11g adapter

Discussion in 'Wireless Internet' started by Grumble, Nov 14, 2004.

  1. Grumble

    Grumble Guest

    Hello all,

    (I am new to Mac and wireless newsgroups. If there are other, more
    appropriate newsgroups, please mention them.)

    I've just bought an 802.11g wireless access point (Linksys WRT54G) to
    share my DSL connection between several computers. I (unscientifically)
    tested the signal quality in every room with a laptop equipped with a
    PCMCIA 802.11g adapter.

    In a specific room, the driver utility claims that link quality hovers
    between 35% and 50% (whatever that means) depending on the orientation
    of the laptop. In that room, I plan to use an Imac G4 (flat panel, round
    base) which came with an "Airport Extreme" slot.

    Customer-Installable Parts Instructions

    What format did Apple use for the Airport Extreme network adapters? It's
    not PCMCIA/Cardbus, is it?

    Is it standard? In other words, if I want to insert an adapter in that
    slot, are there third-party, non-Apple, available adapters out there?

    Do the Airport Extreme adapters have the same range as PCMCIA or PCI
    wireless adapters? PCI adapters have an antenna, most PCMCIA/Cardbus
    adapters have a flat "bulge" which I imagine serves as an antenna. If
    the Airport Extreme is buried deep within the iMac, where is the
    antenna? How can it be effective "inside" the computer?

    I started looking for USB wireless adapters, because they usually have a
    large antenna. Are there third-party USB wireless adapters with Mac OS X
    drivers out there? Are they better or worse than an Airport Extreme
    adapter in terms of range and driver support?

    I plan to use WPA, or 802.11i if it ever becomes available to my
    hardware. I've read that some USB wireless adapters do not support it?
    Is it a hardware or software (driver) limitation?

    I apologize for so many questions, but I must admit I am somewhat
    confused when it comes to Apple hardware.

    I'd be very grateful for any guidance and insight.
    Grumble, Nov 14, 2004
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  2. Grumble

    Bob Harris Guest

    As far as I know, the Apple Airport Extreme card is the only device that
    will plug into the iMac Airport socket. It is most definitely NOT PCMCIA
    The iMac runs the antenna round the edge of the screen. When the
    Airport Extreme card is plugged in, there is a little antenna wire that
    is then plugged into the back of the card.
    You could read about some stuff at the Apple web site

    There is also a book on the market called "Mac OS X Unwired" by Tom
    Negrino and Dori Smith, which should explain some more of your questions.

    However, a few of your questions can only be answered by people that
    have first hand experience, and I did set up my Mom's 17" iMac, I do not
    have experience with 802.11 WiFi running on PCs.

    Bob Harris
    Bob Harris, Nov 14, 2004
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  3. Grumble

    Don W. Guest

    If your Macs have Ethernet connections, use a game adapter (sometimes known
    as a wireless Ethernet bridge.)

    Don W.
    Don W., Nov 15, 2004
  4. Grumble

    Grumble Guest

    As far as I understand, WPA cannot be used when a wireless bridge
    is involved. Am I mistaken?

    Dynamically assigned and rotated encryption keys are not supported
    in a WDS connection. This means that Wi-Fi Protected Access (WPA)
    and other dynamic key assignment technology may not be used. Static
    WEP keys only may be used in a WDS connection, including any STAs
    that associate to a WDS repeating AP.

    Static WEP is unacceptable :-(

    I'm confused, because e.g. D-Link claims both the DWL-G810 and the
    DWL-G820 support some form of WPA (the wording is rather strange).

    (Can anybody tell the difference between the two devices?)

    Perhaps what D-Link calls a bridge is an 802.11-802.3 bridge, whereas
    what Tom calls a bridge is an 802.11-802.11 bridge?

    I think that would make sense.

    Thanks for the suggestion!
    Grumble, Nov 15, 2004
  5. Technically, a bridge is any device that connects one physical network
    to another. In wireless parlance, it usually refers to an access point
    (AP) that connects a wireless network to an Ethernet network (as well as
    functioning as the hub for its wireless network). But "bridge" can also
    refer to a technique of linking two or more wireless access points
    together so that the radio connection substitutes for an Ethernet cable
    between the two devices.

    This technique was often referred to as "wireless bridging" but is now
    generally called WDS, for Wireless Distribution System. It can be used
    to connect wired-only devices to a wireless network. The wireless (WDS)
    segment of the network is invisible to the wired devices, which only
    "see" an Ethernet LAN. The catches: WDS is not yet standardized, so it
    doesn't usually work between APs of different manufacture; and you can't
    use WPA in WDS mode.

    Without WDS-compatible APs, the only way to connect a device --
    computer, printer, game box, etc -- to an existing wireless network is
    with an adapter that functions in client mode. Yet another catch: while
    many APs can now do WDS, very few can operate in client mode. (The way
    an AP or base station usually operates is referred to as "infrastructure
    mode".) Apple's new AirPort Express base station can operate in client
    mode, but only for the purposes of audio streaming and USB printer
    sharing, not for a Mac connected to it via Ethernet.

    There are devices that function as wireless adapters/clients and connect
    to their computer (or game box, etc) by Ethernet rather than through USB
    or a card slot. Their advantage is that they work with any Ethernet
    device and don't require installation of any additional software. Again,
    the computer "sees" only a standard Ethernet LAN: the wireless link is
    transparent. And while "Ethernet-to-wireless external adapter" might be
    a more precise description, these devices are frequently called . . .
    "bridges". D-Link's DWL-G810 is such a device.
    Neill Massello, Nov 16, 2004
  6. The latest firmware release for Apple's AirPort Express and Extreme base
    stations has added support for WPA when using WDS. AFAIK, other brands
    of wireless APs can't do this yet.

    x.html> or
    Neill Massello, Nov 16, 2004
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