Date: Sun, 22 Feb 2004 13:11:34 -0800 From: richard childers / kg6hac <fscked@pacbell.net> To: Neil Camara <neil-on-mobile@restricted.dyndns.org> Cc: freebsd-mobile@freebsd.org Subject: Re: weak signal Message-ID: <40391B06.6050509@pacbell.net> In-Reply-To: <20040222062357.20054.qmail@restricted.dyndns.org> References: <20040222062357.20054.qmail@restricted.dyndns.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Neil, Yes, your 2.4 gHz telephone may well interfere with your 2.4 gHz wireless network. I've noticed that using microwave ovens sometimes interrupts the signal, also. Workarounds relate to how you position your antennas in relation to one another, as well as what you do to relocate or shield potential sources of interference. In general, both transmitting and receiving antennae should be adjusted to be parallel to one another. Specifically, in this case, if your WAP is in the basement and your wireless network clients are on the first floor, you would want to orient your antenna elements so that they were horizontal, so that their signal would be directed upwards, towards the clients .... downwards, towards the basement ... and outwards, towards the neighbors' houses, on both sides ... in a circle, radiating outwards, with your antenna at the axis. Because, to the best of my knowledge, most 802.11b client cards - being PCMCIA-based - are inserted into horizontally aligned bays in the sides of laptops which sit on flat surfaces, it can be said sweepingly that most of the client card antennae are horizontally aligned - or, as we say in the radio business, their signals are -horizontally polarized-. However, because there is still some randomness in how the client cards are aligned - north-south, east-west, or some variation thereof - there is still a great deal of potential for signal loss, because these secondary details of antenna alignment also translate into alignment, or lack thereof, of the sending and receiving antennae, and, consequently, polarization, or lack thereof - with associated signal strength loss. A third factor is proximity. A WAP sitting on a table in the basement is five feet farther from its clients than it has to be. If you can perch the WAP atop a rack, or even attach the WAP directly to the ceiling, you are eliminating a few feet of unnecessary loss of what is already a fairly low strength signal. And there is a fourth factor - intervening equipment and materials. Some materials - such as concrete with a web of steel reinforcing ( 'rebar' ) in the center, or concrete with a high iron content, will absorb the signal. So will a file cabinet that is in the line of sight (although the top of the file cabinet would be a good place for the WAP). Having eliminated all of these factors, if your signal is still weak, you may wish to look into add-on antennas for your wireless card. The high-end cards all have antenna jacks which are more or less industry standard and with a little effort, one can locate small Yagi, and other, antennae, which are designed for the 2.4 gHz spectrum. (The notorious Pringles can antenna is only one of many available - see Google for details.) Making sure your antenna is solidly attached and that no leads are loose in the housing would not hurt, before you go replacing or augmenting your existing antenna, of course. Complementarily, everything described above can be used to shield multiple 2.4 gHz sources from one another, where desirable. Microwave ovens can be shoved up next to file cabinets, on a side away from wireless networks, for example, and wireless telephone systems can be similarly located so that their signals are less likely to overlap with your WAP clients - perhaps the telephone transceiver can be put upstairs, or in one corner of the house, on a shelf, as far away from the WAP as possible, for example. Having put all this solid information out for free, let me add that Daemonized Networking Services handles exactly this sort of installation and administration, for both business and residential customers, throughout the San Francisco Bay Area - please don't hesitate to call if we can be of service, professionally. (-; Regards, -- richard -- Richard Childers / Senior Engineer Daemonized Networking Services 945 Taraval Street, #105 San Francisco, CA 94116 USA [011.]1.415.759.5571 http://www.daemonized.com Neil Camara wrote: > Hey guys, > I am using Netgear MA311 PCI card on FreeBSD as my access point. It's > down in my basement. I am only getting 2 bars in my workstation > situated in 1st floor. Is there a way to make the signal much more > stronger? > I also have noticed that my connection gets drop when I using Uniden > PowerMax 2.4 ghz telephone. Are there any issues? Is there a work around? > Thanks. > Neil > _______________________________________________ > freebsd-mobile@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-mobile > To unsubscribe, send any mail to "freebsd-mobile-unsubscribe@freebsd.org" >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?40391B06.6050509>