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Implementing WiFi in the Real World
John Jorsett writes "Seduced by the siren song of wireless access throughout the home, many a user has experienced the discrepancy between the manufacturer's advertised claims (150 feet indoors, 300 outside) and real-world implementation (the living room and upstairs bedroom may as well be on different continents). In steely-eyed determination to exercise his inalienable right to network access anywhere on his property, MSN author Paul Boutin hired a Wi-Fi engineer to help him bathe his property in 802.11 waves, using only mass-market consumer hardware."
Why? Because they can't act as a bridge AND an access point at the same time.
There are very few products that do this, and Apple's is one of them.
ÕÕ
I've got an extreme near the front of the house and an old graphite in the bedroom.
The nice option about the airport is it will let more than one airport act as the same network - so when I walk from the back to the front of my house, I'm not switching from network 1 to network 2. I know it says it in the article but it's nice to see in action.
FWIW, bathroom tiles are bad for range and for some reason, I have trouble connecting one room away with my tibook unless it is turned just right.
- Zav - Imagine a Beowulf cluster of insensitive clods...
The author thinks the only way to configure the Airport is with a Mac. I have been configuring my Airport from Linux with the Airport Configurator (http://edge.mcs.drexel.edu/GICL/people/sevy/airpo rt).
"Most important, it's the only home consumer base that flaunts its support for the Wireless Distribution System, which knits multiple access points together to act as a single network. An AirPort base plugged into the DSL or cable modem can bridge to up to four additional AirPorts, nearly doubling the network's wireless reach in four directions at once. Even better, the method lets you put an AirPort right in the room with you, rather than trying to beam the connection through a wall. This approach vastly reduces the amount of squirming in your seat required before your laptop will pick up enough signal from the other room."
Total BS. If this guy was a real expert, he'd know you could also buy the Intel 2011 access point (and I'm sure there's others out there with the same feature set). It can also act as a repeater (scroll down on that link a little). I know because I have two in my house, and one repeats the signal to the back half of the house. They work phenomenally.
The Intel may be more expensive (~$500), but I can guarantee it covers more area. The antennas are about 8 inches each (diversity!), and I can actually get my whole house on one of them (why'd I get two? optimal coverage for multiple people...plus it's cool!).
It's true. You need Mac's Airpot Setup Assistant, which is not HTTP based. Maybe one these /. geeks will tell us what protocol it does use and if some incipent OSS project will soon allow non-Mac machines to manage Aiport base stations.
All the nodes on my WiFi network talk in ad-hoc mode, using Mobile Mesh for routing (including the Zaurus). Traffic is then encrypted with IPSec and authenticated against my LDAP server.
As a result as long as I am in range of any one of my nodes (not a difficult thing in this house) I get a good signal - the cloud covers most of the garden too. And all without dropping a bundle on network engineers, antennas, amplifers or anything else.
But then again what do you expect of someone who works for MSN? Routing? Isn't that the thing you do with some kind of workmans tool?
Beep beep.
Maybe one these /. geeks will tell us...if some incipent OSS project will soon allow non-Mac machines to manage Aiport base stations.
Ask and ye shall receive:
FreeBase
There are more links on this page to other packages which do the same thing too.
Mordor...a magical, mythical land where women are more rare than dragons--but where every man would rather find a dragon
D-Link makes the WAP-900+ access point. Cool thing about it is that it can be used as a wireless repeater. I bought one on sale for 69 bucks a few weeks ago. Two of these and a D-Link DI-614+ wireless router ($49 bucks after rebate). would have done the same thing he did for less then the cost of one Airport. Plus you don't need an Apple computer to configure it (any web browser will do).
I first set up my home wireless network with a SMC2632W PC Card adapter. It quickly became obvious that one access point (SMC2655W) wasn't going to cover my 2100 square foot house, so I set up one access point in my study at the front of the house and another in the laundry room at the rear.
Flash forward a year or so, and my employer issued me a spiffy new ThinkPad T30 with an integrated (MiniPCI actually) Cisco Aironet 350 adapter. This adapter uses an antenna that's actually built into the laptop, and what a difference!
There's no question that I could get by with a single access point now. I see 67% signal strength when the adapter is associated with the access point at the other end of the house -- 70 feet away, through four or five walls. In fact, I had a terrible time getting Windows XP to associate with my secured network; it kept associating the adapter with my neighbors unsecured network. (I've promised myself that I'll tell them about this if they ever kill the dandelions in their yard.)
This really isn't surprising when you consider that the PCMCIA adapter has to cram its antenna into the small portion of the card that sticks out of the laptop, while the integrated adapter gets to use an antenna that runs throughout the laptop.
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."
Here's a Java-based configurator for the Apple AirPort Base Station and Lucent RG-1000 wireless access points. It should run on any platform with a Java 1.2-compliant runtime environment installed, permitting the configuration of a base station from any host. The download for Unix/Windows consists of a zip file containing the software and HTML help file. The runnable is supplied as a "jar" file; run this in the usual way (double-clickable in Windows if using Sun's JRE 1.2 or higher runtime environment ; from command line in Unix). The download for the Macintosh expands into a folder containing a double-clickable application plus the help file; a download containing two necessary Java libraries from Sun is also available (see notes below).
The 'duck' antennas that come on Linksys APs are 2.2dBi - they pretty much radiate in a flattened bubble shape.
... think of its pattern as more of a fluffy pancake shape rather than the slightly flattened ball pattern you get with a low gain duck.
If you replace the 2.2 dBi duck with an external 8.2dB omnidirectional antenna you'll have something roughly twice as tall that will put four times as much energy where you need it
I live in an old house with solid wood doors. My desktop provides an adhoc network for my laptop in my room. If either my bedroom door or the office door is open it works with a duck, if they're both closed I get no signal. I had a 17dB panel and the appropriate cable - using this put 32x the energy where I needed it and I get solid connections with both doors closed.
I previously lived in a newer split level. The AP was at one end of the house in the basement, my room was all the way at the other end on the second floor. A 30mw Linksys with a duck was just useless, but adding a 12dB Cushcraft 90 degree sector gave excellent service all over the house.
I am very easy to get along with, but I don't have time to waste being nice to people who are being stupid. -Theo
Does this help?
Now, antennas of various design can give you different shapes. If you are trying to fill an area that is all roughly on the same elevation, use a Higher gain (aroung 8-10db) omnidirectional antenna. If you are setting an access point up in one corner of the property, buy a directional antenna to fill in only the areas you are trying to cover.
In this way you are effectively boosting the output of the equipment without introducing extra noise, or bringing the FCC to your door.
The hard part is interfacing the access point to the external antennas. The back of my linksys's have a reverse-TNC connector. Most aftermarket antennas use the ham-radio style N-type connectors. After a bit of scouring I found an outfit that actually sells the pigtail I needed.
The antennas were from an outfit in Canada called "Superpass". They have a great website with the radiation patterns, but their market is someone buying a messload at a time. I forget where I got the pigtail, but I could probably find it again if asked.
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
Nope, 1/(r^2)
It's called the inverse square law for a reason.
Signal strength vs. distance is proportional to the surface area of a sphere. As you go away from the source, the surface area goes up by the square of the radius.
1984 was supposed to be a warning, not an instruction manual.
Cheap APs have 100 mW or less, and very bad antennas (less de 1 dBi). Nevertheless, a 100 mW card plus a short 2 dBi omni antenna is enough to cover a medium-to-big flat, assuming that the stations' antennas are still internal.
By the way, the Apple Base Station Antena is crap, it only gives good coverage if you have all the stations' antennas at the same level/height, otherwise better to turn the base station on its side or hang it in the wall.
sgis ddo ekil t'nod i
See Tom's Hardware for an article on D-Link's Repeating WAP.
802.11b/g:
;)
:)
If you have a Linksys 802.11 b/g router (WRT54G), then you have boughten a piece of crap. No seriously, that router has terrible range. I should know, I used to have one. I verified on the net, that is was the case. I exchanged it for a Netgear WGR614, which uses an Intersil PrismGT chipset, and my coworker bought the DLink variety, which also uses the Intersil PrismGT chipset. It gets MUCH MUCH better range.
With an Intel 802.11b gateway that I used to have, I would get -65db signal in my master bedroom, and XP would report VeryGood connection. With the Linksys G router, I got -77db, and XP reported Poor signal connection. When I connected the Netgear G router, I got -57db and XP reported Excellent signal strength. I borrowed a friends signal booster, and connected it to the linksys, and found it to be useless.
I ran NetIQ and did some through-put tests. With the Linksys, I got 17mbit/sec when I was in mixed mode, and 20mbit/sec in G only. On the netgear, I always got 21mbit/sec. With the 802.11b, I got 4.5mbit/sec...
802.11a:
With an AP based on the Atheros 5000 chipset, I got crappy signal at our work. Thanks to Tomshardware, I bought a Netgear WAB102, which is the ONLY A/B dualband AP that uses the second generation A, (Atheros 5001) chipset. This thing is awesome. At our work, its coverage actually exceeds that of B.
At home, I get -59 to -65db in the master bedroom on A. However, the cool thing is the throughput. In non-turbo mode, I get a constant 24mbit/sec in the master bedroom. On the G router, it seemed to be more sensitive to the signal strength, as it would always connect at 36mbit/sec or 48mbit/sec, consequently, I only get 21mbit/sec throughput if I was in the computer room. In my bedroom I got between 14-18mbit/sec.
With A however, I got 24. And I enabled Turbo mode, and it connected at 108mbit/sec, and I measured a constant 35-40mbit/sec everywhere in the house! and thats a two story house, with the AP upstairs.
Keep in mind the "b" radio in the Netgear WAB102 is a piece of crap Atmel chipset. Everytime I "accidently" rest my arm on my card, I lose connectivity. I found my Prism2/Prism3 cards would go into 1mbit/sec mode, and never recover, unless I unplug the card, and plug it back in. The A radio in it on the otherhand is truly awesome.
In the end, I returned my G router, and kept the Netgear WAB102 dual band A/B, and reconnected my Intel gateway for the B, and use Netgear for A.
Atheros has an white paper they posted talking about range and such of A and B, and testing results in an actual home environment and corp environment. Its rather interesting. I verified it myself at our office here with my own testing with various A and B equipment along with Netstumbler and NetIQ, and it is truly suprising.
So anyways, most range problems can be attributed to a shoddy AP, not the "technology". I mean, I've tested the Netgear WAB102, Netgear WGR614, Linksys WRT54G, Linksys WAP54G, Intel ProWireless 5000AP, Intel Gateway, DLink DI-624, and the Linksys BEFW11S4. I tested with Orinoco Silver, Linksys WPC11V3, Linksys WPC54G, Linksys WPC55AG(my fav card), Cisco Aironet 350, Linksys WUSB11 v2.6, and assorted generic Prism2 cards, so I can safely say I know what I'm talking about
(I work in a lab and have lots of wireless toys, if you guys can't tell
I sucessfully downloaded and installed the alternate firmware for the Linksys WAP11 and boosted the wattage on all channels. I can now sit across the street and get online, just make sure you don't forget to enable WEP.
We tried it, but it doesn't support the WDS parameters yet.
Paul Boutin | writer for Slate, Wired, etc
Unfortunately, none of the apps we tried including Freebase include support at this time for the WDS parameters introduced with AirPort Extreme. In the case of Freebase, we couldn't even get it to connect to our Airport Extreme bases. If you have better luck, email me.
Paul Boutin | writer for Slate, Wired, etc
They're talking about the Airport *Extreme* basestation. The Java Configurator works great with the older airport basestations, but I question whether it works with the newer Airport Extreme basestations.
Crimony, how many times does it have to be said! Microwaves (and other RADIO freqs) do NOT cause cancer, sterilization, mutation, etc. Those are caused by IONIZING radiation, such as ultraviolet, gamma, and X-rays. Ionizing radiation lives at the OTHER END of the radiation band from radio/microwaves. Yes, microwaves can cause injury, but that injury is limited to THERMAL effects (i.e. cooking), and maybe burns from inductive electrical effects causing arcs from metal objects. Again, let it be said: radio towers don't cause cancer! RF from power lines doesn't cause leukemia! Microwaves won't make you sterile! Your cell phone did not give you brain cancer! It's radio for gods sake! It's not a "nookular bomb"!
If a job's not worth doing, it's not worth doing right.