• I have mine...I have run the CAT5E and I'll punch it..

    let's see where do those Green and Orange wires go again..??

  • can any one send me the basics concept of 802.11e

  • Compughter Escribi?3:

    I have rooms that are hard to penetrate in hotels at times, and am only using 5dbi gain omni directional antennas. Can't use amplifiers with APs if they are not certified together per FCC part 15 to boost the signals?

    Here's my thinking on this:

    Extra antenna gain is unlikely to help. My experience is that 8" to 12" thick poured cement walls absorb about 15 dB of signal strength. Let's say for sake of argument that the signal is hitting the wall exactly at the point where FSPL causes it to hit the receive sensitivity threshold of the client. In other words, client on one side of the wall just barely gets a connection, client on the other side of the wall gets nothing.

    How much antenna gain would you need to get the signal through the wall? Answer: 15 more dB. You would have to go from a 2 dBi antenna to a 17 dBi antenna JUST to get the signal to the other side of the wall, and even then, it wouldn't actually propagate into the room.

    Okay, so that's a hypothetical, but the point I'm trying to make is that concrete walls are SO absorptive that you need a ridiculous amount of antenna gain just to get through ONE extra wall. It's hardly worth it, in my opinion. Who's going to install a 17 dBi omni antenna indoors?

    Exception: If you've got just one concrete wall that you need to go through, antenna gain can be effective. Like if you were going from outside a cement-walled warehouse to inside. But if you've got a bunch of cement construction, like all the interior walls are cement, good luck.

    Amplifiers? Make sure you get one that works on both the transmit and the receive side. Since the client devices probably won't have amplifiers, boosting the AP's transmit power won't actually increase the effective range of the link, since the clients won't be able to talk back. For this reason and others, I haven't found amplifiers to be a particularly effective solution either.

    When I have experienced buildings with lots of concrete construction, my answer is usually just to increase the number of access points. It stinks for the guy who has to buy the access points, but it seems like the most effective solution. Typically, I see about three times as many APs being required, compared to drywall construction.

  • Motorola's Broadband over Powerline (BPL) Solution

    An innovative solution, Powerline MU enables service providers, building owners and businesses to transform a building?¡é?€??s internal electrical system into a powerful communications network. Powerline MU uses Canopy Access Points and Subscriber Modules to send signals to a Powerline MU Gateway. The Gateway then injects the signal directly into the electrical lines. For broadband access, subscribers simply plug their computer or router into the Powerline Modem. Since the Gateway is located in the building?¡é?€??s electrical distribution area, coordination with the electric utility is not typically needed. A licensed electrician is required for gateway installation.

  • Joshua,
    From personal experience I can confirm that you are correct about the high gain antennas. I have come upon many hotel installations that have a one Watt amplifier with a 14-19 dBi antenna connected. Do the math on that one. The previous installers are trying their best to save a buck.
    Now, they do penetrate walls ok, but still in one direction. Keep in mind, most old hotel concrete is only about 3" thick between interior walls.

    On a different note, I have a secret sauce that I use for hotels without increasing the number of AP's. In many buildings doubling the number of AP's will more than triple the cost. The reason? Wiring those darn AP's.

    What I have found that is contrary to what I always read is that a laptop's transmitter can penetrate 2 floors of concrete and still get a signal back to the AP. As you know, antenna gain goes both directions.

    Using the logic that I always read, given that a laptop card (PC Card, Mini PCI, USB) has the same receive sensitivity as an AP, then why should the AP ever have a higher transmit power than the STA? My AP's are over 10dB more powerful than most STA's cards but that is the only way it will work. I guess the only explanation would be that the receive sensitivity of the AP is much better than the STA's. Thoughts?

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