3.1 Hotspots

It would be pretty much impossible for any notebook user not to have heard the term hotspot . Wireless hotspots are popping up in many locations; coffee shops , airports, hotels, conferences, restaurants , city parks, and libraries are just a few places where you might find a hotspot.

You can easily build your own hotspot, and we cover this in detail in Chapter 6. A hotspot requires at least one access point, a good antenna that covers the needed area, a broadband Internet connection, and some form of access control (if you want to restrict access).

Most hotspots are built around these four basic pieces. Some use DSL as their broadband Internet connection, while many of the commercial hotspots use a T1 line or other dedicated circuit. However, many hotspots are simply in a house or apartment, particularly in dense urban areas, and these connections are DSL, cable, or even simply dial-up.

Before you leave for a trip, research online to find hotspots along the way to your destination. To find both fee-based and free hotspots, consult the following web sites:

WiFinder

http://www.wifinder.com/search.php

HotSpotList

http://www.hotspotlist.com

T-Mobile Hotspots

http://www.t-mobile.com/hotspot

Wi-Fi Zone Finder

http://www.wi-fizone.org/zoneLocator.asp

JiWire

http://www.jiwire.com

3.1.1 Wireless Hotspot Providers

There are an increasing number of commercial hotspot providers, ranging from large companies, such as T-Mobile and WayPort, to small operations in local coffee shops, and wireless aggregators that allow you to access multiple networks from different hotspot providers.

Nearly all of these providers restrict access to their hotspots through a captive portal . This form of access control intercepts all TCP/IP traffic. To gain access through a captive portal, simply open a web browser and attempt to navigate to any web page, such as http://www.oreilly.com . Your browser traffic is intercepted and redirected to the login screen of the hotspot's portal software. Figure 3-1 shows a typical hotspot login screen.

Figure 3-1. Typical hotspot login to a captive portal

With commercial hotspot providers, you have a number of payment choices for access. The large operators all offer monthly subscriptions in addition to pay-as-you-go pricing. This is convenient if you don't want to sign up with a specific provider or if you don't travel enough to justify the $20-40 per month that most monthly subscriptions cost.

If you travel frequently, you may want to sign up with one of the wireless hotspot providers. Deciding which one to use is tricky. It really depends on where you think you may spend the most time. T-Mobile provides access in nearly all Starbucks coffee shops, as well as Borders bookstores, Kinko's copy centers, and many airports. Surf and Sip has neatly taken up many of the non-Starbucks coffee shops in major cities. WayPort is a good choice if you need hotel or airport access.

Associating with a hotspot provider is easy. They all have easy-to-identify SSIDs. You can also locate their hotspots ahead of time using their web pages. Table 3-1 lists some major hotspot providers, their SSIDs, and their web pages for locating their hotspots.

Table 3-1. Hotspot providers, SSIDs, and location finders

Hotspot provider	SSID	Web location finder
Cometa	Cometa-Hotspot	http://www.cometa-hotspot.com/locations/
STSN	STSN	http://www.stsn.com/hotel_locator.php
Surf and Sip	SurfandSip	http://www.surfandsip.com
T-Mobile	tmobile	http://locations.hotspot.t-mobile.com/
Verizon Wireless	Verizon	http://www.verizonwireless.com/wifi/hot_spot/
WayPort	wayport	http://www.wayport.com/locations

3.1.2 Wireless Aggregators

With the rise in availability of commercial hotspot providers comes a conundrum : which hotspot provider do you sign up with? As you've seen, there are many providers, and each of them has different coverage. If you're a real road warrior , using several different hotspots could cost quite a bit.

Wireless aggregators have come into the market to address this problem. You sign up for an account with the aggregator, and through its revenue-sharing agreements with different hotspot providers, you are able to use many different hotspots while maintaining a single account with one company.

That's the theory. In practice, roaming is still very difficult, especially for non-Windows users. Boingo (http://www.boingo.com), the largest aggregator, requires the use of proprietary software on your notebook, and as of this writing, that software is Windows-only. There are reports of adventurous people running the Boingo software using a Windows emulator like Wine, but we're not going to attempt to cover that here. Unless the web-based captive portal offers a roaming option, roaming with Boingo and Linux isn't possible at this time.

Two other aggregators fall into the same category: Trustive (http://www.trustive.com/) provides only a Windows client software package, and iPass (http://www.ipass.com), while providing clients for Windows, Windows CE/Pocket PC, Mac OS X, and Mac OS, does not provide a Linux software client.

Fortunately, there is at least one roaming company that has gotten it right: FatPort. FatPort's roaming customers don't need any special software. Its locations and partner locations all use captive portal software that requires only a web browser.

Although FatPort is based primarily in Canada, it has a wide range of partner agreements with Surf and Sip, Boingo, and iPass. While not a complete coverage of all roaming sites, this is an excellent option for the Linux user who is constantly on the road. FatPort accounts range from hourly rates to yearly subscriptions. Check out http://www.fatport.com for more details.

3.1.3 Open Hotspots

Just as the software world is split into proprietary and open source, the hotspot world is populated with commercial hotspots (which we've covered) and open hotspots. These open wireless networks span a wide range of locations and philosophies:

• Businesses providing free wireless access as an incentive to customers. Hotels, coffee shops, restaurants, bookstores, and other businesses are all using free wireless access as a way to bring in customers and entice them to stay.

• Public places serving up hotspots as a public service. Libraries, city parks, town squares, city halls, and other publicly owned spaces view free wireless access as a way of promoting their city, county, or other locations, and attracting visitors .

• Community wireless groups working with businesses, governments , and private citizens placing hotspots in all sorts of locations, including apartment buildings , parks, downtown areas, and any place that would benefit from free wireless access. Many community groups view this as a way to better their neighborhoods.

Open hotspots are a mixed bag. You may simply be associating with a wireless router in someone's apartment, connected to his DSL line. On the other hand, it may be a custom-built Linux-based access point in a New York City park, installed by NYCWireless (http://www.nycwireless.net), with a T1 or DSL backhaul.

Access control is also going to vary. If you connect to someone's home network with an SSID of "default" or "linksys," chances are you won't find a captive portal or any other form of access control in place. Many community and business that open hotspots have some sort of access control in place, such as a web page that asks you to agree to a Terms of Service (ToS) agreement before you are allowed to use the network.

A good place to locate open hotspots is the Personal Telco Project in Portland, Oregon. Visit its Wireless Communities site at http://www.personaltelco.net/index.cgi/WirelessCommunities. A second place to look for hotspots is WiFiMaps at http://www.wifimaps.com. This site, while still in development, shows you hotspots all over the world.

3.1.4 Associating with Hotspots

To associate your Linux notebook with an open or commercial hotspot, you have a couple of options. If you know the SSID of the hotspot, simply set the SSID using iwconfig :

 $  iwconfig eth1 ESSID SurfandSip  

Once you've done this, fire up your favorite web browser, attempt to navigate to any web page, and you will be redirected to the hotspot captive portal login, as shown in Figure 3-1.

If you've settled in a coffee shop that has an unknown hotspot provider, the first thing you can try is:

 $  iwconfig eth1 ESSID any  

If there is a hotspot in range, your card should find and associate with it. This can be tricky, especially if you're in a densely populated urban area. For example, sitting in a coffee shop in San Francisco, we were able to associate with four different SSIDs. The signal strength from the coffee shop hotspot was not as strong as a neighboring open hotspot located in someone's apartment.

In these cases, you want to identify all of the access points in your immediate area before you decide which one to associate with. There are several methods of finding access points with Linux, and we cover each one in turn .