1. Introduction
Welcome to the irc.freenode.net/#wireless Frequently Asked Questions page. Look here first for resources and tips on doing your Wifi magic.
Other FreeNode channels with more specific help, please consider them:
#madwifi: MadWifi support channel - http://madwifi.org - Latest stable release: v0.9.3.3
#openwrt: Kamikaze 7.09 is ready - http://kamikaze.openwrt.org | Documentation http://kamikaze.openwrt.org/docs/openwrt.html
#ndiswrapper: "Linux driver for WLAN (802.11[abgn]) [Latest stable: 1.48] Homepage Read Wiki first, especially FAQ, before asking for help. Note that for kernel/module compilation issues, there are other places to look, e.g., #kernelnewbies or internet search."
Other websites you should look at for help are:
http://wireless.kernel.org/ : Information about Wireless Networking (currently only IEEE 802.11) on the Linux operating system.
http://WWW.HPL.HP.com/personal/Jean_Tourrilhes/Linux : The Linux WLAN Driver HowTo page
http://www.seattlewireless.net/index.cgi/HardwareComparison List of cards, chipsets and drivers that support them
http://Prism54.org/supported_cards.php : Linux support for Prism54 based 802.11a/g cards.
http://HostAP.Epitest.FI/ : Linux support for Prism 2.0/2.5 802.11b cards.
http://madwifi.org/ : Linux support for Atheros based 802.11a/g cards.
http://WWW.MattFoster.Clara.co.UK/madwifi-faq.htm : MADwifi FAQ
http://MADWiFiWiki.TheWebHost.DE/wiki/FrontPage : MADwifi wiki. Contains helpful 'user recipes'
http://Linux-LC100020.SourceForge.net/ : linux support for ZyDAS 1201 based 802.11b devices.
http://ACX100.sourceforge.net/ : Linux support for TI ACX100/111 based cards. The ACX111 is not quite there yet.
http://linux.oldcrank.com/tips/wpc11 : Tips for setting up a Linksys WPC11 (or, get a real card).
http://nocat.net/faq.txt : The NoCat Wireless FAQ
http://wifiadmin.sourceforge.net/ : A hotspot management system with user support.
http://getwifi.sourceforge.net/ : A script that joins wireless networks based on precedence.
http://www.wireless.navigator.co.uk : Tools and information.
http://m0n0.ch/wall : An all in one firewall package.
Community Wireless Networks who hang out here.
http://www.manchesterwireless.net : The Manchester Wireless broadband project.
http://www.houstonwireless.org : The Houston Wireless User's group.
http://www.nycwireless.net : New York City Wireless - Hotspots for the pigeons.
http://www.seattlewireless.net : The Seattle Wireless Community Network Project.
http://www.bcwireless.net : The British Columbia Wireless Network Society.
http://www.personaltelco.net : The Personal Telco Project.
http://www.e3.com.au : WAFreeNet.
See also : WirelessCommunities
The Questions!
Contents
- Introduction
-
General IRC Channel Questions
- Who runs the channel
- Is irc.freenode.net the same as irc.freenetworks.org
- Where did irc.freenetworks.org go?
- I asked a question but no one is answering me!!
- I'm a profiteering wisp and I hate you non-profit idiots
- Some asshole named 'jmc' banned or kicked me. Wtf?
- Why am I op'd?
- Who is WifiFred?
- Are there channel archives?
- Community Wireless Issues
- Commercial (for-profit) Wireless Issues
- General Linux Stuff
-
Wireless Network Card Questions
- What is the best 802.11b wireless card?
- Will my D-link DWL-650+, 3Com USR2210 (or other TI chipset 22 Mbps hardware) work in Linux or *BSD?
- What about driverloader / ndiswrapper?
- Will my Broadcom chipset wireless card work in Linux or *BSD? (Linksys wmp11v2.7 and Dell Truemobile 1180 for example)
- Will my Atmel chipset wireless card work in Linux or OS X? (SMC2632W)
- I'd like to try doing ___________ with 802.11b. Will it work?
- Do 802.11a cards work under Linux or *BSD?
- Do 802.11g cards work under Linux?
- I'm trying to use my ________ (prism2 chipset card) under linux, and I can't figure out wlan-ng, help!
- What driver should I use for Linux?
- How do I get my Linksys WPC11 to work under Linux?
- How can I find out what chipset my wireless card uses?
- I want a wireless network scanner under Linux, or help configuring one, please?
- How do I enable monitor mode with this Orinoco?
- Will my USB wireless adapter work under Linux?
- How can I find what version of Firmware my Wireless Network card has?
- I want to install some kind of authentication software for my wireless network, can I do that?
- I'm having trouble with my prism card....
- What's an easy, reliable way to update the firmware of my prism card?
- Antennas and stuff
- Connecting to Networks
- Network Configuration help
- Building A HotSpot or Network
- Security Concerns
2. General IRC Channel Questions
2.1. Who runs the channel
The #wireless channel is maintained by people from various wireless groups and walks of life. The rule of the channel is largely egalitarian in reflection of the openness of unlicensed radio spectrum and the spirit of many community wireless networks.
2.2. Is irc.freenode.net the same as irc.freenetworks.org
No, irc.freenode.net is a seperate IRC network.
2.3. Where did irc.freenetworks.org go?
The irc.freenetworks.org server is offline but the rest of the WirelessIRC network can be reached through one of these servers:
- irc.personaltelco.net (US) Linked to irc.bcwireless.net
- irc.bcwireless.net (CA) Where most CWNs reside.
irc.efnet.net #swn Where you can find SeattleWireless
- irc.sydneywireless.com (AU)
2.4. I asked a question but no one is answering me!!
- Most of us have jobs away from chatting in IRC. If you asked a question but no one answered, it's likely because no one knows, or has the time to answer. Hang around for a while and someone might have an answer for you. Don't repost your question over and over though, it'll only serve to annoy other people in the channel.
2.5. I'm a profiteering wisp and I hate you non-profit idiots
- Maybe you should use #wisp instead.
2.6. Some asshole named 'jmc' banned or kicked me. Wtf?
- As part of a new initiative to return the signal to noise ratio of #wireless to something endurable, jackasses will now be kickbanned whenever 'jmc' notices them. The criteria for jackassery include, but are certainly not limited to: describing your commercial activity with such vigor and repetitiousness it becomes a shill so shrill only dogs can hear it, answering questions pedantically and then immediately transitioning into shilling, asking stuff in the FAQ over and over again like a moron, etc. etc. In general, don't be stupid.
2.7. Why am I op'd?
- Short answer: No particular reason.
Long answer: Some of us (notably matthewa) observes that privilege is more or less irrelevant. Some people think that having "ops" is a symbol for having higher privilege, or stature, but in the real-world of license-exempt wireless networking there is no such thing. Consider being a victim of mass-oping a sign of the times, no one has more obvious privileges than the other.
Some people, like grumpydog, view +o as an issue of . They believe that no one but those few who individuals who contribute in some way (often in the form of monetary investment to the host network, FreeNode) to give them an absolute right at having control over others. Ignore these people, they're full of shit.
If you think it's dumb that everyone has ops, that's fine. If you think everyone having ops is asking for trouble, you could be right, but maybe you should read WhyWikiWorks to get an idea of why it doesn't *really* matter. If you still don't get it, don't fret, no one will bother explaining it to you. The concept may simply be too obvious for you to "get".
2.8. Who is WifiFred?
WifiFred is our IRC Bot, he maintains a database of various Wireless and Internet related things like Cable types and Internet Standards. He also does simple calculations on Fresnel zones and Path Loss. For brief help, use !help .
See WifiFred for a complete command reference and additional information.
2.9. Are there channel archives?
- Nope. At least not that we're going to admit to quite yet.
3. Community Wireless Issues
3.1. Where can I find a Community Wireless Group to hook up with?
The WirelessCommunities page has a list of groups around the world.
The FreeNetworks.org WirelessNetworkingProjects page lists some more.
NodeDB.com lists community wireless nodes around the world.
3.2. Where can I find peering agreements for Community Wireless networks?
The original PicoPeer agreement
FreeNetworks Peering Agreement
Also check out the FreeNetworks community mailing list.
3.3. Where can I find an acceptable use policy for my community wireless hotspot?
4. Commercial (for-profit) Wireless Issues
4.1. How can I make money?
- Q: I have a great idea on how to serve my local starbucks and makes loads of cash. How do I do it?
A: Go here and don't bug us.
4.2. Why are WISPs so hostile to community wireless?
- Not all are, but occasionally we run into the odd WISP who will spew fud about Community|Open Wireless Networks.
Just ignore them, they're nothing more than PissAnts. If you're getting tired of all this WISP-oriented silliness in the channel as of late, try irc.personaltelco.net / irc.bcwireless.net / irc.sydneywireless.com
5. General Linux Stuff
5.1. How do I install <blah> package?
Read this.
5.2. Are there any small linux distros with wireless?
Yes. Pebble Linux has the latest wireless tools plus things like NoCatAuth built right in. It is a FreeNetworks project maintained by Terry Schmidt of NYCWireless. It is designed for single board computers, but can run on a laptop, old PC and other x86 based machines. Pebble is the default OS on the Metrix Kits
Latest: http://pyramid.metrix.net/trac/
LEAF is another small distribution that requires less space and has a menu interface, but has less advanced features.
Other: CQureAP (one floppy, kernel 2.6, hostap), WarLinux (outdated).
6. Wireless Network Card Questions
6.1. What is the best 802.11b wireless card?
- This is a highly subjective question. It all really depends on what you are going to do with it.
Some say the best all around wireless card is an old Lucent/Orinoco Silver or a Gold card. They have good OS support, an internal as well as an external MC-Card antenna jack, and have one of the highest receive sensitivities on the cards in the 30mw-50mw range.
If you are looking for a high powered PCMCIA card, you may want to get a 200mw Senao Card. There are two models of card, one with an Internal Antenna only, or a card with 2 diversity (both listen to the wireless signal, and the antenna with the most signal wins) external MMCX antenna jacks. Senao cards are less flexible since there are two models, but the added power and excellent receive sensitivity make them a good choice for outdoor links as well as wardriving and monitoring applications.
If you are looking to make a machine act as an access point under linux, you really only have two options. HostAP and MadWifi. HostAP has been around longer and is considered stable, but because it is based around the Prism2 chipset, it lacks 802.11g and 802.11a support. Old hermes based chipsets (the old Orinoco cards) cannot act as an AP under linux without HermesAP which may get you in hot water, and also you will miss out on a lot of the new stuff.
If you are going the HostAP route, you might want to look into the Zcomax Prism2Card or the Senao 200mW cards. An unofficial support page for SenaoCards is maintained by SeattleWireless.
MadWifi is a relatively new driver (grab the CVS version), it works with Atheros based cards, allows you to act as an AP, do WDS as well as tap some of the more advanced parts of the wireless card. It seems to be the driver to get if you are into trying new things. You can get Orinoco branded PCMCIA cards as well as MiniPCI Atheros Cards
6.2. Will my D-link DWL-650+, 3Com USR2210 (or other TI chipset 22 Mbps hardware) work in Linux or *BSD?
Yes. There's the ACX100 project available at http://acx100.sourceforge.net , which managed to write an OSS driver despite
- not getting any chipset specs from TI, D-Link or USRobotics. Please tell TI, D-link et al. that real Linux support would be greatly appreciated. Note that similarly named cards usually will NOT work with this driver, due to D-Link's highly idiotic product naming policy.
Note: The '+' in the D-Link model number denotes a TI chipset, therefore you should use this ACX100/ACX111 driver. The 11b cards will use ACX100, 11b/g dual-mode radios use the ACX111 version
6.3. What about driverloader / ndiswrapper?
- When all else fails, there are other methods to getting your radio to work under linux. This should be the last resort as functionality is limited and can cause problems. The following link sums it up quite well...
http://acx100.sourceforge.net/ndis_cludge.html
And as far as getting monitor mode to work using this method, you're SOL. Have fun.
6.4. Will my Broadcom chipset wireless card work in Linux or *BSD? (Linksys wmp11v2.7 and Dell Truemobile 1180 for example)
- Yes.
A Linux driver for the Broadcom bcm43xx wireless chips: http://bcm43xx.berlios.de/
Check here for a Windows driver wrapper. (See above)
6.5. Will my Atmel chipset wireless card work in Linux or OS X? (SMC2632W)
Maybe, look at http://atmelwlandriver.sourceforge.net/news.html
There is an OS-X driver available as well.
Linksys has published Atmel source code, available from ftp.linksys.com, specifically here. If not, you're probably out of luck. Contact the manufacturer, and failing that, return the product. Side Note - The SMC2632W has 3 Revisions the First Revision marked by a fcc id of WL1100 is a Prism2 based card and will work with the prism2 drivers. The rev one will say WL1100-1 also it only has one orange colors light. This is the same unit as the US Robotics 2410 card.
6.6. I'd like to try doing ___________ with 802.11b. Will it work?
- Dunno, maybe. Wireless networking depends on so many different factors that it's impossible to say for sure. Try it and let us know.
6.7. Do 802.11a cards work under Linux or *BSD?
Linux drivers are available from the MadWiFi source forge project.
Note that some hardware combinations (such as the VIA EPIA board) may need IO address reservation, otherwise MadWifi won't find the card. example:
- For Atheros+Pebble+VIA-EPIA, add 'append="reserve=0xd3405fff,0x2000" ' to lilo.conf (This address may vary, so take note of the exact error beforehand..)
An Atheros gifted driver is available in FreeBSD 5-CURRENT (aka: FreeBSD 5.2). See the ath man page for more details.
OpenBSD has support as well. See the manpage. If you have an unsupported chipset, contact the manufacturer, then return the hardware.
6.8. Do 802.11g cards work under Linux?
Yes. There is the prism54 project and the madwifi project.
Here is a mini-howto for getting a linksys dual band card to work using the madwifi driver.
If you are using the MadWiFi drivers and the card won't seem to associate with your Access Point, like my (solarce at fallingsnow.net) Netgear WG311 (a good buy, $60 shipped at newegg.com) was.
- Then just follow these easy step for Linux powered 802.11g bliss.
- 1.) (Assuming you've installed the madwifi drivers from cvs and loaded the 'ath_pci' driver) ifconfig ath0 up 2.) iwconfig ath0 ap xx:xx:xx:xx:xx:xx (this is the mac addy of your ap, you can probably find it with 'iwlist ath0 scan') 3.) iwconfig ath0 channel XX (1-11, whatever your wap is set to) 4.) iwconfig ath0 essid your_essid_here 5.) iwconfig ath0 rate XXMB (your rate here, i.e. 11MB, 54MB) 6.) ifconfig ath0 x.x.x.x OR dhcpcd/dhclient/pump ath0 (for dhcp goodness) 7.) Let Cool and Sprinkle with Powdered Sugar (ok not really)
And now you have 802.11g under Linux, me, I am using the card in my shiny new xp 2700+ powered MythTV machine, (http://www.mythtv.org) Enjoy!
6.9. I'm trying to use my ________ (prism2 chipset card) under linux, and I can't figure out wlan-ng, help!
You might want to try using HostAp ( http://hostap.epitest.fi/ ), it is a driver that supports ad-hoc, infastructure and master modes, and uses the linux wireless extensions, so you can configure it with iwconfig, unlike wlan-ng.
6.10. What driver should I use for Linux?
For lucent/orinoco cards use orinoco_cs. Prism2/2.5/3, HostAp is strongly suggested. Cisco/aironet cards, airo_cs. You can get rpms of kernels including hostap at http://www.cat.pdx.edu/~baera/redhat_hostap/ These are using the redhat patched kernel source, with hostap included.
<coderman> Chalain : choosing wlan-ng over hostap is like a child accepting a ride from
a strange man offering candy with one hand down his pantsSee the links in this section for more information.
6.11. How do I get my Linksys WPC11 to work under Linux?
First, you need to figure out which version of the card you have.
- WPC11 v.4 is based on the rtl8180 chipset.
- WPC11 2.7 is based on ???
- Other versions (at least, 2.0, 2.5, 3.0) are prism2-based.
If you have one of the earlier cards (v 2 or 3) go here:
Or, you can try looking here:
I do not recommend following the latter directions, as the drivers are not totally compatible with the linux wireless extensions, which are a standard all the other drivers follow. If you choose to use wlan-ng, please don't expect any support what so ever from #wireless. Try following directions for other prism2 based cards, orinoco_cs and hostap will also work, and both support the linux wireless extensions. --ForrestEnglish
If you have a v.4 (rtl) card, you should go here:
As of early 2007, they do not have a release, and encourage downloading the svn. However, they also have posted tarballs of previous snapshots, and you should download one of those tarballs. Once you extract the tarball, you will see several directories, which correspond to different development versions of the driver. The one you want for WPC11 v.4 is rtl8180-sa2400-dev. You do not need the ieee80211 replacement stuff.
Note: that driver (and in fact the entire rtl-wifi project) is a fork of an older project: http://rtl8180-sa2400.sourceforge.net/ However, the rtl8180-sa2400 project has been abandoned, and does not work with modern kernels (I think it broke with 2.6.15). There is also a proprietary driver available from RealTek, which is even more out of date and does not work for most people.
6.12. How can I find out what chipset my wireless card uses?
One way is to find the FCCID for the card (usually on the card itself) and search the FCC's database: http://www.fcc.gov/oet/fccid/ Another is to check these lists that others have compiled:
http://seattlewireless.net/index.cgi/HardwareComparison : Covers most client adapters and APs, good notes on connector type, power, drivers and even price.
http://www.linux-wlan.org/docs/wlan_adapters.html.gz : Probably the most extensive out there, but lacks in helpful tips found on the previous list.
http://madwifiwiki.thewebhost.de/wiki/WifiCards : A list pertaining to devices that use the Atheros chipset, check here for some user feedback.
http://www.mattfoster.clara.co.uk/madwifi-hw.htm : Another list of Atheros radios.
6.13. I want a wireless network scanner under Linux, or help configuring one, please?
For linux the best option is definitely Kismet. Kismet supports a very wide range of cards. See the Kismet Readme for more information.
6.14. How do I enable monitor mode with this Orinoco?
Latest information on orinoco radios and enabling rfmon (monitor mode) can be found here. And specific notes on 2.6 kernels here. There is a guide to setting up kismet 2.8 using linux 2.4.20 and an orinoco wireless card here.
6.15. Will my USB wireless adapter work under Linux?
Driver for the ZyDAS ZD1211 802.11b/g: http://zd1211.ath.cx If you are using a prism2 usb adapter, I wish you luck with wlan-ng.
Nowadays a lot of USB-wireless adapters are well supported under linux , have a look on this page wich tells chipset/manufacturer are good and bad. It also provide you with the links to the site's where the driver are available.
6.16. How can I find what version of Firmware my Wireless Network card has?
- You can find out what firmware you are using by checking /var/log/syslog or /var/log/messages (depending on your distro) when you insert the card. This may or may not work I'm afraid, but you should definitly look.
6.17. I want to install some kind of authentication software for my wireless network, can I do that?
Most access points have mac address limiting options, and also you could enable WEP. Mac addresses can be faked however, and WEP can be broken fairly easily. If you just want to keep causual users off your network, WEP would be your easist solution, just check out the manual of your access point for instructions on enabling this. A better solution might be to use real authentication software like NoCatAuth.
You'll probably want to be comfortable with linux to do this, and use a linux machine as the router either using HostAp or with the access point hooked up directly to the machine. Then you'll want to checkout http://nocat.net for authentication gateway software called NoCatAuth.
6.18. I'm having trouble with my prism card....
Make sure you have the most up-to-date firmware! It's 1.8.4 for most prism versions. See next question.
6.19. What's an easy, reliable way to update the firmware of my prism card?
I (DrDT) have updated the firmware of many different kinds of prism cards using this method (on Windows). It requires modified Senao drivers, the winupdate program, and the correct firmware files for your card. You can find the correct firmware types from this table http://linux.junsun.net/intersil-prism/IDtable.html . Match your "Component ID" (see hostap_diag under linux; or winupdate in windows may show you) against the table and you'll find what primary and secondary firmwares you need. Then you can find the latest primary (pL######.hex, where L is the letter for your primary type) and secondary (sL######.hex, where L is the letter for your secondary type) firmwares on sites such as http://linux.junsun.net/intersil-prism/firmware/
Most people will have cards of type 800C or 8013 in my experience; according to that table those types of cards require a "K" Primary and a "F" secondary. the latest versions of these are at http://linux.junsun.net/intersil-prism/firmware/1.8.2/PK010101.HEX (primary "K" version 1.1.1) and http://linux.junsun.net/intersil-prism/firmware/1.8.4/sf010804.hex (secondary "F" version 1.8.4)
Make sure you have the right type of firmware, and no programs running/problems with your computer during the update. Any small error will permanently kill your prism card! Ask me in the channel if you have questions.
Here's my recommended procedure to update your prism card on Windows:
1) get the Senao prism driver http://www.netgate.com/info/miniPCI/Prism/Drivers/DriverSetup802.zip
2) get the winupdate program http://linux.junsun.net/intersil-prism/WinUpdate-0-7-0.exe
3) get the 2 firmware files which match your card, the primary and secondary according to the info above.
4) After removing any old prism drivers (in add/remove programs usually), install the Senao driver. Then go into your windows inf directory (usually C:\windows\inf\ or C:\winnt\inf) and open the wlannic.inf file. In that file there will be lines near the top starting with "ExcludeFromSelect..." put a ";" character in front of those lines, that way you can choose/force the senao driver for your non-senao prism card.
5a) If you have a PCMCIA card: When you insert your prism pcmcia card, it'll ask for a driver. Select "choose from list" in that box and select the "IEEE 802.11b" manufacturer and the "PCMCIA card" or "PC card" device option. (if you don't see "IEEE 802.11b" to the left as a manufacturer, you didn't install the senao driver of modify wlannic.inf correctly).
5b) If you have a PCI/Mini-PCI card: delete the card from the windows device manager (usually right click my computer -> manage -> "devices") and press the "f5" key to re-detect your hardware. If this doesn't work (no box pops up after f5), restart your computer. When windows asks for a driver, Select "choose from list" in that box and select the "IEEE 802.11b" manufacturer and the "PCI" or "Mini-PCI" device option. (if you don't see "IEEE 802.11b" to the left as a manufacturer, you didn't install the senao driver of modify wlannic.inf correctly).
6) After installing the card, go to your prism card's driver's options and disable the "Firmware Download" option. If you don't do this, the Senao driver will put a newer firmware in the card's RAM (it has a few RAM firmwares built-in), but not its flash, and winupdate will show you the wrong firmware version. Restart your computer afterwards to make sure.
mini-PCI bugnote: a user with a Thinkpad x22 laptop and Mini-PCI prism card still had this RAM firmware problem even though he followed step 6 and rebooted. It seems that the thinkpad kept his card powered throughout the reboot, preventing it from clearing out its RAM firmware. If you have a Mini-PCI card and the RAM firmware is not going away, remove all power (cord & battery) from your laptop for a bit.
7) Install and run the winupdate program. Your card should be automatically selected.
8) Add the 2 fimware files above using the "file" menu. Those 2 files should be listed in the main winupdate box, each having a P or an S icon depending on primary/secondary firmware.
9) We'll check your card's current firmware to make sure we're putting the right stuff on. In Winupdate, go to tools menu and then "query firmware version". Make note of the 2 files listed in that box:
- if the first file starts with an A (instead of P) or the second file starts with R (instead of S) (e.g. RF10... instead of SF10...) it means that your card is using as its firmware a temporary RAM firmware uploaded by the driver. This is bad! review step 6 above to prevent this.
- compare the 2 files listed to be the same types (first *2 letters* are same in each) to the firmware files you downloaded. For example, if you're using the "K" primary and "F" secondary, the files you downloaded would be PK.. and SF..., and the files listed in the winupdate info box would be PK... and SF... If they don't match, you have a problem, stop!
10) Now make sure your PC won't be bothered during the flash procedure (no programs running, etc) and...
- Press the "flash" or "update" button... I forget what it is. Anyways, it'll ask for confirmation and then will start flashing your radio for 2 minutes. If all goes well, your prism card will have the newest and greatest firmware. else, you're screwed and your card is dead :-(. But odds are in your favour!
Again, if there are any questions, ask in the channel.
7. Antennas and stuff
7.1. dB, dBm, dBi, mW, W.... What is all this stuff?
- mW stands for miliwatt, W for watt. Sometimes we talk about watts, but usually we talk about dBm, dB and dBi. Simply put, dBm is the amount of power your radio transmits. dBi is usually the amount of gain your antenna has. You can add dBm and dBi together to find out a rough idea of how much "power" the card and antenna will put out.
For an explanation on the dB stuff, check out the DeciBels page.
7.2. How can I calculate the distance my antenna will have?
It depends what you're transmitting through. First you need to know what your FreeSpaceLoss is. Assuming you have perfect LineOfSight, the FSL at 5 miles is 118.36 dB. At ten miles it's 124.38 dB. Then you do this:
( txdB + txdbi ) - fsl + ( rxdbi ) where: txdB is the amount of power your radio transmits at (in dBm) txdBi is the amount of gain your antenna has fsl is the amount of loss in dB between the two sides of the link rxdbi is the amount of gain the ''recieving'' antenna has.
If you do have trees, buildings, bad coax cable or anything else that can impede the radio signal(besides the open air between the antennas), try and figure out what the loss is in dB and add it to the fsl value. This'll come up with a number, probably negative. This number is the amount of radio energy that receiving side will be able to "hear" (under ideal circumstances that is!). The object of the game is to get the receiving side
hearing a signal of at least 10 dB more than what the receiving radio's http://wiki.freenetworks.org/index.cgi/ReceiveSensitivity is.
You can also use the commands !range, !fsl and !rxsl in the IRC channel to do the math for you.
7.3. What is the best antenna?
- There is no right answer to this, please look up the radiation patterns of antennas you are interested in and see if they will fit your needs. Parabolics are good for long distance links, Helicals, Waveguides and Yagis are generally good for medium distance links, Sector antennas are good for medium distance links or large area coverage, and Omni antennas are good for large area coverage.
7.4. How can I hack an antenna onto my wireless card?
- If your card doesn't already have an antenna connector, you should return it and buy one that does (ORiNOCO, Cisco, EnGenius/Senao and a few D-Link's have proper connectors). Seriously.
7.5. I want to build my own antenna, where are instructions to do that?
- The cantenna is really the only antenna that is even worth building yourself anymore as antenna prices drop slowly, and we realize what a PITA and a time sink it is to build a quality antenna yourself. But, we do understand the desire to build your own when you first get into this wireless stuff, hell, we did. The cantenna is a waveguide antenna made from a tin can, with a copper wire and an N connector, it can be built in 20 minutes and $5 worth of parts, and will give between 8 and 16 dB of gain have been reported.
Here are instructions for the cantenna: http://www.turnpoint.net/wireless/cantennahowto.html
More antenna designs: Do-It-Yourself Wireless Antenna Update
A page whith lots of links about DIY antennas Http://www.paramowifix.net
The biquad is also an easily constructed antenna, providing about 11dBi gain. A slightly larger variation, the double biquad, provides about 13dBi gain. The biquad has a wider beamwidth (~40 degrees) than a cantenna, making it very suitable for wireless stumbling.
For detailed information on constructing a biquad, refer to this page: http://martybugs.net/wireless/biquad/
7.6. What's the deal with reverse polarity (RP) connectors?
- "Reverse polarity connectors have the normal "male" and "female" inner connector parts swapped over so that female contacts are used in the plug connector and male contacts in the jack. Their purpose is to prevent the user from inadvertently plugging in equipment (such as a radio antenna) that differs from the type specified by the manufacturer."
8. Connecting to Networks
8.1. How do I find wireless networks around me?
You can use a utility to scan for networks around you. Some popular utilities are ApRadar, NetStumbler, Kismet and many more. Take a look at WarDriving and the CategorySoftware page.
8.2. How do I connect to a wireless network?
This is different in each operating system, see AssociationWithNetworks and find your operating system's instructions. Also, there is a tool that does this Getwifi.
8.3. How do I hack into my neighbors Wireless Network?
- Knock on his door and ask if you can use his network. He'll be able to help you get on.
8.4. How do I crack WEP?
- see above.
8.5. Why won't someone on #wireless help me crack my, ahh, own network ?
Unfortunately, we can't verify if you are cracking your own network, or someone elses. We can't and won't be party to a criminal act, and seriously, none of the community wireless groups can do with the resulting negative publicity. Google can help you instead.
8.6. What system do I need for 902.10 Wireless on my TV
You need what we call a "DMCA Take Down Notice" operating system. Email piracy@mpaa.org with the subject line of "dvd decss movies for free" and give them your full mailing address, as well as a list of what programs and movies you want to get for free over your wireless connection.
9. Network Configuration help
9.1. How do I setup my network to automatically get an IP address?
This is currently covered in NetworkCommands.
9.2. What commands do I need to use?
The NetworkCommands page lists commands used to configure IP address information once you have your radio associated with the access point.
10. Building A HotSpot or Network
10.1. What is a captive portal?
See CaptivePortal
10.2. What captive portal/gateway software is available?
See PortalSoftware
10.3. Where can I find documentation on NoCat?
Check NoCatSoftware for initial help. See also NoCatAuthInstallationGuide NoCatAuth NoCatSplash and for authentication help (if you choose to use this extra feature): AuthService SameMachine
10.4. Some people say that since NoCat isn't maintained anymore that I shouldn't use it??
Clearly they don't understand what NoCat is. At it's basic level, NoCat essentially manipulates IpTables rules to allow or deny access. So unless NoCat can't work with IpTables anymore, then yes, you shouldn't use it. In short, it works perfectly fine and a lot of people still use it. Including 95% of PersonalTelco node builders and members. If you want maps, and other fancy options, then you should look elsewhere. NoCat is a tried-and-true solution that has been working for a long time.
11. Security Concerns
11.1. How broken is WEP, anyway?
- WEP isn't secure, period, if you're interesting enough for someone to devote a lot of time to hack you. if you just want to keep people off your network, it should be fine. But it's not a alternative to using real encryption and authentication software.
11.2. So what could I use, then?
- You could examine the various device level standards supported by your vendor, such as WPA/802.11i and 802.1x. Also, you might want to consider IPSEC, PPTP, or another VPN solution. These would allow you to secure your own traffic from eavesdroppers, while still allowing open access (without using a seperate AP for a secure channel).
You don't really need any device level encryption however. Using GPG for email and https for secure browsing and such would protect you much beter then any device level encryption ever could. It would also offer much more features (like authentication for your email) which are imposible with device level encryption. So don't be fooled in to believing that you are secure and safe with only device level encryption. You're not.
==Which card/driver combination has the best support for WPA?==
Help with windows specific stuff in NetworkCommands and AssociationWithNetworks would be greatly appreciated. I have pictures and commands for the orinoco software under windows that I can take care of, but anything else is fair game. Further wikiizing this page (like the lucent cards), and any further FAQ's would also be welcome --ForrestEnglish