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The Wireless Networking Question Roundup...
Which 802.11b-enabled PDA?
Kent Brewster asks: "I've retired my Palm 7 due to sudden lack of all-you-can-eat service and lots of free WiFi in the area. Right now, I'm looking at HP's iPAQ h5455, Toshiba's e750, Palm's Tungsten C, and Sharp's as-yet-to-ship Zaurus 5600. What I'm after is the best possible mobile Web experience first and PDA functions second. Opinions, please?"
802.11b Issues for Apartment Complexes? (Revisited)
johaninroseville asks: "I am in the planning stages to build a wireless network to provide an apartment complex with last mile Internet access. There are about six hundred units, but only one to two hundred interested people. For those curious as to the general layout of the apartments, here is an overhead picture.
My experience with radio frequencies, antennas, and especially how well radio waves can penetrate walls etc is rather limited. My game plan is to get a feed into the POP / MDF, and have a rather strong omni antenna mounted on the roof of that building. The coverage of that omni antenna will provide the links to the seven APs that will probably be needed, mounted on the rooftops around the complex. The seven IDFs, (or APs or what ever you want to call them) will each have a Point-to Point connection to the big omni antenna. Hardware used for the seven IDFs is planned to be: directional antenna (for link to omni in POP) connected to bridge, bridge connected to AP, AP connected to a sectored panel antenna that will provide end-user access (to their PCMCIA/PCI/CF/USB Cards, or to their access point).
My biggest questions are what antennas to use? What strength? How well can the radio waves from an omni antenna and/or a sector antenna penetrate multiple walls, if at all? How far can one of these antennas cover, and then penetrate walls?
I would appreciate any help at all in this matter. Maybe somebody has done something similar, or have some useful links."
Ask Slashdot last covered wireless apartment complexes about a year ago, and it would be interesting to note if any of the new technologies, introduced in the interim, will make this job any easier.
Outdoor Enclosures for 802.11b Equipment?
And finally, this question from ETEQ: "I need to operate a small amount of networking and wireless equipment (Router, Cable Modem, and 802.11 access point) in an outdoor setting, but the problem is that I live in Minnesota, where temperatures can drop far below freezing and stay that way for weeks (not to mention frequent heavy snow)... Are there any outdoor enclosures that can be purchased on a Home or SOHO budget?"
If the fine folks at Tupperware/Rubbermaid can't help, how about Coleman or Igloo coolers?
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A couple of weeks ago, I got a chance to dink around with the Tungsten C at CompUSA and browsed around to a couple of sites, including Slashdot, and the web browser seems to render pages a lot better than Pocket IE included with the Pocket PC OS. Pocket IE is closer to IE3/IE4 than current versions of IE (though IE in CE.NET, which isn't available for Pocket PC hardware, is closer).
Either browsers do not support pop-up windows, which is both good (for pop-up and pop-under ads) and bad (if you are using a webmail system that depends on pop-up windows). Also, trying to read something on a 320x240 screen is a wee bit difficult. The Tungsten C's display (320x320) gives a little more real estate for rendering web pages, though the fonts used my take a little getting used to if you are used to Verdana, Times or Bitstream's Vera.
Speed-wise, the Tungsten C seems a bit faster and more responsive when browsing the web than an iPaq with the same processor, memory and built-in WiFi. For me, the location of the navigation disc is a bit too low for me, but after using it for a couple of minutes, I got used to it.
As far as a previous poster's question on why 802.11b instead of 802.11g? I think there are a couple of reasons right now: 802.11g eats up more power (thus run a bit warmer) and the chips used for it aren't as compact as 802.11b chips... that and I'm not sure how much I/O is provided between the processor and the bus that the WiFi controller would connect to (which could end up being a bottleneck). That and I think almost all of the 802.11g PC Cards available right now are CardBus only, which I don't think any PDA (clamshell or not) supports.
Or am I feeding the trolls again?
Forward, retransmit, or republish anything I say here. Just don't misquote me.
I am running an open node in my apartment with a broadband Net connection. A co-worker in the same building has wireless, but no Net connection and was hoping to use mine, but the signal was too weak. The other day he was checking the signal again and found yet another 802.11B AP that gave him a good signal and had a Net connection.
My point is this: Just encourage as many people as you can to set up open AP's using off-the-shelf AP's and whatever Net connection they have. Don't tell the providers. Don't worry about setting up complex routing or other network stuff (except making sure the AP's are on different frequencies to avoid stepping on each other). Don't sweat the details. Don't worry about who pays for what. Just do it.
The amazing thing about 802.11B is that it will probably work fine.
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Are you an SF Fan? Are you a Tru-Fan?
one of the WISPS here in Iowa throw the equipment into an old cooler, then water proof it with silicone. Not sure if straight Styrofoam or like a Coleman one. I just remember the guy saying it has survived -20 and +100 degrees on op an old grain silo.
My choice is PocketPC for several reasons. First up, lets not beat around the bush. Palm is currently playing catch up when it comes to having multimedia and Internet capabilities on their PDAs.
Browsing has been and continues to be pretty lousy on Palm devices mostly due to the available browsers. Having 802.11 speeds is waisted when your browser can only render text and simple images. PocketPC's all come standard with PocketIE which is basically a light version of IE. It renders pages very accurately (layout wise) considering the available screen real estate. Which leads me to my next point.
Another big plus for PocketPCs is that there is software to increase your screen resolution. So if you wanted, you can rotate the display and bring it up to 800x600 for a better browsing experience. Granted the screen gets pretty blurry at those resolutions but it's still very usable since the tools let you click a button to zoom in and out quickly.
Going beyond web browsing, tools such as SSH clients, FTP applications, network monitors are all much more mature on the PocketPC platform compared to Palm. There's also the added bonus of having native versions of the Windows Media player, the Macromedia Flash 6 player and even the Windows Remote Desktop client for true Mobile computing on a PDA.
Don't get me wrong, I do like the Palm platform. My current PDA is a Handspring Treo 300. But web browsing is definitely sub-par compared to my old iPaq 3600. As far as Linux PDAs are concerned, I'm sure someone else here can comment on those.
The ultimate Wi-FI PDA appears to be the Samsung Nexio S160, with a big, high-resolution screen for Web browsing. It's not officially sold in the USA, it runs WinCE, and it costs as much as a computer, though.
Lurking inside your cellphone is a vastly underused computer. One inventive programmer figured out what to do with it.
by Paul Wallich June 2003
Way back at the dawn of time--say, 30 years ago--when Alan Kay was pioneering windowed displays on a personal computer and Doug Englebart was inventing the mouse, either of them would have killed for a modern cellphone. Not for the instant communication, which would have required another billion dollars' worth of towers, transceivers and switching equipment, but for the computing power. The megabyte or four of memory and the couple of multi-megahertz CPUs that are standard on today's Web-enabled mobiles dwarf what you could find on almost any machine available to the developers of Unix, e-mail or the Internet. Yet most of the time, all that computing power just sits unused.
Therein lies an opportunity.
Most of the current generation of cellphones support Java, a combination of programming language and libraries that lets developers write compact code and run it on many different machines with minimal customization. Obviously, you can't just sit down at the keyboard--so to speak--of your Motorola, Nokia or Samsung and start coding, but building programs for a Java-enabled phone is relatively simple. Download the Java development environment of your choice, snarf a few extra bits of code from the phone manufacturer's Web site, and type away.
When you're done, simply insert a link to the compiled code onto a Web page, download it with your phone's browser and presto! (For hackers who haven't got a new-model cellphone and aren't willing to buy one just to run their code, Motorola, Nokia and others offer emulators you can run on a PC that allow you to see the cramped little images and push illegibly labeled buttons on your screen.)
Since Java-enabled phones became available around the turn of the millennium, thousands of apps have made their way onto the Web, ready for downloading. In addition to retreads of every game that ever graced an 8-bit cartridge system back in the 1980s--from Pong to Space Invaders to Pac-Man--hackers have managed to cram chat clients, low-resolution porn, grocery-list managers, news- headline scanners, webcam viewers and streaming-video clients into people's pockets and onto their belts.
If some of these apps make it seem as if Java-based cellphones aren't fully tapping all that power under the hood, well, that's by design. Victor Brilon, Java applications manager at Nokia, and Charles Chopp, Nokia's media relations manager, laughed when I asked questions about writing Java programs that make full use of a cellphone's computing and communications power. As on PCs, Java apps on cellphones run in a "sandbox" that prevents them from doing damage to their surroundings. So no dialing out, no messing with other programs loaded on the phone, no access to the digital signal processor that encodes and decodes the digits representing your voice, which is by far the more powerful of the phone's two CPUs. There's a legit reason for this good-fences policy: Imagine accidentally downloading a scrap of code that dials 911 every five seconds, or a malicious app that records snippets of your phone conversations to the phone's RAM and then calls random numbers in your address book to play them back.
A revised version of MIDP (Mobile Information Device Profile, the standard for running sandboxed Java apps on handheld gizmos, including cellphones) scheduled to be released this summer allows users to allot more access to their phone's resources to "trusted" apps that have been vetted by the manufacturer or some other industry-approved authority; watch for the first round of train wrecks soon after its release.
So if a hacker can't implement all of Microsoft Office or find the next Mersenne prime on a cellphone, what is it good for? State the question another way: Besides old video games, what really interesting applications accommodate lousy graphics, marginal memory and a user interface consisting of a d
I saw a few posts about cordless phone interference and 802.11 and wanted to add a recent experience. I recently added the MP3 capapbility to my Tivo and was streaming MP3s off my shared drive (linux of course) via 802.11b. Works great. (The Tivo MP3 play functionality sucks but thats a different story). So i'm listening to the music just fine and my wife puts dinner in the microwave. Now we have all heard about microwaves interfering with 802 before but i have never had a problem before. So as soon as she turns on the microwave, the music cuts out. The microwave counts down 3...2...1 and queue the music. While I have run the microwave for years while surfing the web and checking email, I have never noticed the problem. The statelessness of web surfing masks the interference of the microwave. The MP3 streaming highlights the issues of microwave interference. The moral of this story, don't count on 802 for network connectivity.
Older buildings in older areas can have more durable walls and floors.
In the US NJ area, quite a few brick buildings will have very sturdy floors and good, thick walls that happily block all wireless traffic. One almost never earns a noise complaint except in rare occasions or downstairs neighbours with super-human hearing. 225 St Pauls Ave 07306, St 1A : Sacks Realty, go see the demo unit. Now, if only the windows were more sound-proof to block out the sirens.
By contrast, the west coast of the US is riddled with newer (10 yr) buildings with very poor lateral AND vertical soundproofing, and one needs to look VERY hard for a decent unit where any effort has actually been made to prevent intra-building squabbling. From what I've seen on my part of the west coast recently, the rarity of sound-proofing seems to suggest it's considered a 'premium' addition to any building, while what I've seen of apartment complexes on the east coast seems to suggest it's automatic.
Maybe west-coast americans are a bit too apathetic and/or deaf. It took me 24 apartment viewings to actually find something under $2/sq with flooring that felt thicker than one-ply, so YMMV.
With the number of people getting wireless devices for their homes riseing and the people still forgeting to secure their routers and access points to prevent unsigned people from using their connections, an amazing new concept up as popup in my appartment complex. Their is a shared access setup going on. Everyone here has a different type of connection (Cable, T1, DSL, Satelight, and even DialUp) but most of us use a wireless router so we don't have to run 10base-T around our appartments. After booting up and checking for SID broadcasts comming to your card or access point its amazing the number of people who don't secure them. After asking around I found out that they don't secure them for a reason. The arpartment complex is on a shared internet system. Everyone who has a connection opens themselves up to everyone else. It gives us the ablity to go to the pool with our labtops or walk our dogs with our PocketPCs or allow friends to use your connection when your isp is being slow. We respect each others line and know that if we abuse a friends connect that our mac address will get banned. What it has turned is a massive internet shareing community. A wonderful paradise of highspeed access where ever you might go. I wonder if anyone else has done anything like before?
No.
Instead of blasting each building with one big antenna (at a relatively high power) have you thought about running leaky co-ax (AKA radiating cable) in the hallway celings? Depending on the amount of re-bar in the floors, you could probably get away with every 2nd or 3rd floor.
one manufacturer's product
another
and another (PDF)
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"I can't complain, but sometimes still do..." Joe Walsh
I totally agree with the idea of using directional antennas.
The first wireless set up I did, I figured put the antenna up high where everything can see it. Even though I was only using it as a way to connect a one building that was offnet to another that had a T1 coming into it. Trouble is I put it up too high and picked up other traffic that interfered on all the available channels at times. We called in an expert. He placed antennas that were just powerful enough to do the job in out of the way corners so that the antennas could only see each other and nothing else. (Of course still try to make it in a place that you can access and get a cable and power to. Nothing comes easy)
In your case the interfering traffic would be your own AP's. Buildings and trees can block signal. This is NOT a disadvantage. It is an advantage. Put small directional antennas below the roof line to connect one building to the next. Place them as much as possible so that they can only see one antenna on one other building. If you do not have enough shadows try to keep any antenna in view of at most 3 other antennas. One you bridge to is on your channel. The other two would be on the other channels.
Wire each building with ethernet and a switch. Use the wireless to avoid having to wire across the complex, not for client access. Each building becomes a link in the chain. You do not hav to dig trenches or put up phone poles.
If the walls block enough signal the users can still have cordless phones and microwave ovens.
If the walls are brick or use steel studs you may let the user have their own in house AP's plugged into your ethernet jacks.
This is all based on NYC brick, concrete and steel construction. I don't know what effect those suburban, grey-vinyl siding, chipboard and sheet rock apartment complexes I see on the side of the highway while travelling have on 2.4Ghz signals. They may be totally transparent with no attenuation whatsoever. In that case put up a huge omnidirectional antenna and blast as much power through it as the FCC will let you.