I recently moved to an area that is not serviced by DSL (too far from the CO), Cable, or fixed wireless. The only thing available here is satellite with its not so wonderful 400ms+ latency, and dial-up at 26k max. You have to understand that moving to such a place after having 4-6Mbps DSL for years is like a drug addict stopping their habit cold turkey - dial-up users everywhere, I feel your pain!

Welcome to the 21st century, where your local Starbucks is also your ISP. Starbucks began offering wireless internet access to its patrons (and to anyone else within range of its wireless signal) two weeks ago via T-Mobile's hotspot service. Since I live 3,500ft away from a Starbucks and I have line of sight, that means me too.

Thankfully, T-Mobile has good taste in hardware. Even without an external antenna on their building, their 100mw Cisco Aironet access points are powerful enough to send their signal to your nearby home/apartment. They have to be that powerful, really, to enable patrons with junky 802.11b cards to surf while sipping their Espresso Macchiato outdoors on Starbucks' patio.

With a WiFi 802.11b card and an antenna, their service is 1.5Mbps up and down for me, thanks to their full T1 pipe, and costs $30/mo for unlimited hours and unlimited data transfer with a 12 month contract, or $40/mo with no contract.

So, you live within a mile of a Starbucks and want to get up and running? Lets get started:

First, make no mistake about it: nothing in this article advocates breaking the law or hacking into networks. If you want to use T-Mobile's service, get an account and pay their monthly fees. Besides, T-Mobile uses RADIUS authentication, so you can't just hop on board anyway.

I'll assume that you have heard of 802.11b but have never set up an 802.11b network. If that's you, great. If you know how to setup an 802.11b network, that's fine too - you're a step ahead.

To connect to Starbucks' T-Mobile service, you need an 802.11b WiFi card. Here's fair warning: not all cards are created equal, and unless you live on top of a Starbucks, you're going to want to get a card that has both a good receive sensitivity, or signal strength at which it is capable of operating, and a good level of transmission power.

There is a table of receive sensitivities for 802.11b cards at FreeNetworks.org. The Demarc Relia-Wave 180mw (Retail $149) is my favorite, and it's what I use. Its receive sensitivity is the best out there, and it packs 180mw of transmission power, which is pretty much as high as it gets for an 802.11b card. The Lucent Orinoco card would probably be my second choice, though I have not actually tested one for this application. I did try a Zoomair 802.11b card and would not recommend it for this particular application - it is best for indoor 802.11b networks in my opinion.

Once you've chosen an 802.11b card, it's time to do some testing. First I'll assume that you have a laptop to use for this step. If not, don't worry, you can do this testing from home too (though you will more than likely need an external antenna - see below). Install the 802.11b card in your laptop and configure your wireless software to use an ESS ID of "tmobile". Go into your local starbucks and fire up your browser. Starbucks' T-Mobile login page should appear in the browser. Sign up for a free 24 hour account and check it out - it should be very speedy.

Even though your wireless software probably includes a "link quality" and "signal strength" meter, I would recommend downloading a program called Netstumbler to help you with the testing phase. Netstumbler gives you all kinds of cool details such as signal strength, noise level, and signal to noise ratio, and can even identify all 802.11b networks within range (which many people refer to as "wardriving", but which is a bit beyond the scope of this article). Netstumbler only supports certain cards. The Demarc Relia-Wave Card and other Prism 2.5 based 802.11b cards will work, but many cards won't. If it's important to you to be able to use Netstumbler, be sure you buy a card that it supports.

Now with the laptop running Netstumbler, start walking towards your house/apartment and note the signal to noise ratio of your T-Mobile connection in Netstumbler, or your signal strengh and link quality in your 802.11b card's software as compared to those numbers inside Starbucks. As you put distance between yourself and your favorite coffee house, the signal will decrease. If the signal strength decreases below the sensitivity of your card, it will disappear, and if it is too low, you'll have a poor connection. I found that an SNR of about 30+ is optimal, though the connection will work well with an SNR as low as 12-15 (using the Relia-Wave card). Depending upon the type of card you have, chances are, you won't be able to get more than a couple hundred feet away before you lose signal. If you live within range - great, you're connected. If not, you'll need an external antenna.

External antennas come in a variety of shapes and sizes, and the performance of each is rated in "dBi gain", which is a measure of directivity, or the ratio of radiation intensity in a specific direction to the radiation that would be obtained if the antenna radiated the signal in all directions. I can give you a rundown on the different types of antennas, but I can't tell you what's right for your application. If you live within 1000-2000ft and have line of sight, you're going to need a lower dBi rated antenna than if you live over 2500ft away and do not have line of sight. In fact, because Starbucks didn't exactly think to put an external antenna on their buildings, if you live over 2500ft away and do not have line of sight, your chances of receiving the signal are unfortunately slim, but might be worth a shot.

Parabolic Grid Antenna

Yagi Antenna

Patch Antenna (30°)

For my particular application, I chose a 24dBi parabolic grid antenna and a 180mw Demarc Relia-Wave 802.11b card. It worked out to be a perfect combination for me - though barely enough power/reception to achieve a good connection due to a few partial line of sight obstacles and the fact that the signal is having to penetrate through walls and glass.

I'll take this opportunity to mention a limitation of your WiFi system: the FCC sets a limit on your maximum transmission power, which is a factor of the actual milli-watt rating of your radio (802.11b card), and the "dBi" gain rating of your antenna. There is a maximum, and even if there wasn't, you don't want to end up with a higher power output than you need for a quality connection (because you may cause intereference for others, for one thing). If you use a 24dBi directional antenna (which is pretty much as high as you can go without a 6 ft. dish) and a 180mw card, you're likely fine, but consult the rules if you get any ideas about adding external signal amplifiers. For a directional antenna that is pointing at a fixed point, like Starbucks, the FCC requires that you reduce a 1 Watt transmitter by 1dB for every 3dB of signal that your antenna gain exceeds 6 dBi. Whew! In English, in the case of a 24dBi directional antenna, you're allowed a maximum power of about 250mw for this application. Keep in mind though that any cable run will introduce loss into your signal and offset your antenna gain.

Although there is a math calculation that you can do to figure out whether or not the antenna you've chosen and the card you're using are likely to give you a strong enough signal over your specific distance, it's fairly useless in this case since we're not talking about distance between your antenna and their antenna, we're talking about having to receive a signal through who knows what sort of wall materials and/or glass, and to transmit your signal through the same. Trial and error is involved here, unfortunately.

You may need to do some extra research to choose an antenna. I would recommend a highly directional antenna as your goal is to send and receive data from one specific point, not to radiate your signal all over the city. A parabolic grid antenna may be required (and was in my case), but a high-gain Yagi or patch antenna are good choices as well.

To connect your antenna to your 802.11b card, you'll need a "pigtail" adapter. Antennas use an "N-type" connector, and are either N-Male or N-Female, so choose a short pigtail with the appropriate match for your antenna, and make sure that it works with your card.

Now go home, connect your antenna to your card, and fire up Netstumbler. Chances are, you'll pick up several 802.11b networks in your area as you pan your antenna around. You're concerned with the "tmobile" network. Experiment with different antenna positions and angles to achieve the maximum signal strength and signal to noise ratio. Once you know the general position that the antenna needs to be in, SLOWLY sweep side to side, then up and down, to find the best position. Netstumbler can help with that task, as it has a MIDI/audio feature that plays higher/lower pitched tones to help you aim the antenna without having to look at your PC/laptop. I wish I could give you a more scientific approach, but I just spent the better part of a week crawling all over my roof and walking around my back yard trying to find the best angle - it's tough climbing on a roof while holding a parabolic dish and a laptop, let me tell you. I finally found the sweet spot, and the reward is 1.5Mbps up/down, 24/7, though the graph below indicates a slightly slower connection at that particular time.

Speed graph courtesy BroadbandReports.com

So there you have it. Highspeed wireless internet for about $275 startup (802.11b card, antenna, pigtail, and cable) plus $30/month.

If you need to distribute your wireless connection to multiple PC's, you'll either need to use Windows XP / Windows 2000 internet connection sharing, or build a router using Windows 2000 Server or a Linux homebrew. You could also buy a Wireless router/bridge to use in place of a PCMCIA 802.11b card to distribute the connection.

Connect your antenna to your 802.11b card or router (you'll need a PCI bus PCMCIA card adapter if you're not using a laptop with a native PCMCIA slot) using the shortest possible run of appropriate cable, no less than LMR-400 type/rated cable. LMR-400 cable is made for wireless systems and is low-loss, losing 6.8dB of signal per 100 feet. So if you bought a 24dBi antenna and you're running 100ft of LMR-400, you just cut your antenna down to 17.2dBi. Other cable types are available, ranging from LMR-100A to LMR-1700, with dB loss decreasing as the LMR number increases, and with cost increasing as the LMR number increases.

A very important note here: if you care at all about the data that you're sending and receiving, pay close attention. The datastream between you and Starbucks is completely vulnerable to reception. Anyone could drive by your house with an antenna and intercept the datastream. You might as well open up your window and yell your usernames and passwords to your neighbors. Therefore, it is important to adopt new security measures. The exception here is SSL, which is encrypted, but POP based email, HTTP web browsing, telnet, etc, are all 100% vulnerable, so additional security (like SSH tunnels) should be implemented.

It goes without saying that you should be running a firewall like Zonealarm (at least), but 802.11b communication dictates that you go way beyond that. For my systems using this T-Mobile connection, I use SSH to encrypt all data that is sent to and from my system over the internet. My incoming and outgoing email is encrypted, all of my web browsing is encrypted (by first tunneling to a proxy server that I control), and I use Trillian's secure feature for secure instant messaging. If you don't know how to setup SSH tunnels to encrypt your data, and you want to, start a thread in the TechIMO forums for help. Also see Rob Flickenger's article, Using SSH Tunneling.

Some day we'll all be surfing the Net at >1GBps with unlimited bandwidth for $15/mo, but until then, Starbucks' T-Mobile service beats dial-up hands down if you're unlucky enough to not have DSL/Cable and lucky enough to live within range.

Resources:

Hardware/Wireless