So, you've gotten your shiny new EVDO datacard working under Linux (if not, see High-speed cellular wireless modems (e.g. EVDO, HSPDA) in Ubuntu GNU/Linux 6.10) and you want to now setup the actual Internet connection?

In this article I document how I setup Sprint's Mobile Broadband service with ppp in Ubuntu GNU/Linux 6.10.

Note: If you are running Ubuntu 7.04 or greater, this article is no longer relevant. Your EVDO modem should be detected and run at a higher speed automatically.

I've been raving about cellular wireless modems/data cards for a while now. While they've been available for a long while, they've finally become practical with networks such as EVDO and HSPDA that offer broadband-like speeds. I personally own a Novatel Merlin S720 that I use with Sprint's Mobile Broadband service.

Most of these datacards are easy to get running in Linux--I actually setup mine in Linux faster than I did in Microsoft Windows. However, due to some shortcomings in the kernel used by Ubuntu GNU/Linux 6.10, you cannot take advantage of the speeds that these modern wireless networks offer.

This article talks about some of the problems of the often-used usbserial driver, and how to use the better-performing airprime driver instead.

I'm a T-Mobile Hotspot subscriber, but I cannot say I'm particularly happy with it. Reliability is in general pretty good, but there have been a few times a certain hotspot has been flaky, and these tend to be the times I needed access the most. It's also a pain to have to go somewhere to get Internet access, especially when, for example, I don't like Starbuck's coffee. I rather have the Internet come to me.

Enter EVDO. It's a 3rd generation cellular technology that allows for broadband-like speeds, typically almost everywhere you have a cellular phone signal. There are different speeds depending on what network is available in a particular location:

• 1xRTT, allowing for 144 Kbps/144 Kbps download/upload speeds
• EVDO 1x Rev 0, allowing for 2.45 Mbps/150 Kbps
• EVDO 1x Rev A, allowing for 3.1 Mbps/1.8 Mbps speeds.

All three types of networks are available can be found in the United States, and a typical provider's access plan lets you roam between them anywhere in the country for free.

Access comes through a provider-specific modem (i.e. you cannot use one provider's modem with another provider). These usually are PCMCIA cards, reminiscent of the 802.11b network cards people used before WiFi was built-into notebook computers. Connection to a provider usually is provided through PPP software. Most the modems available on the market today are a little oddball: they expose a USB controller, which then exposes a USB serial interface which controls a virtual modem. Yes, it's strange, especially when these devices aren't actually modems (there is no MOdulation or DEModulation taking place, the devices are more “network bridges”), but thankfully it allows these devices to easily work with alternative operating systems like Linux and MacOS X.

In the USA, there are essentially three major EVDO providers: Sprint, Verizon Wireless, and Alltell, with Sprint and Verizon having the largest networks by far. What differentiates the Sprint and Verizon, I think, is pricing and policies. If you do not want to sign a contract, both providers cost the same. If you want to sign a contract for 2 yrs, you only get a discount rate with Verizon if you've a qualifying voice plan—Sprint has no such limitation to get a discounted rate.

Verizon does a bit of questionable marketing: they advertise their service as “unlimited,” but they pull a trick often used in contract writing and specifically define “unlimited” as 5 GB/month. If you go over this limit, you're breaking Verizon's terms of service. Verizon often cancels subscribers accounts, and assumes you are a criminal, downloading illegal music or software. An article in the Washington Post, Bandwidth Bandit, discusses about one subscriber's woes. Their terms of service disallows many popular Internet applications as well, such as VoIP, video conferencing, or any online gaming. Sprint's terms of service are more vague and do not explicitly disallow these things, but reports from their subscribers say that they don't have unreasonably low bandwidth limits nor have draconian policy enforcement assuming you guilty until proven innocent.

This wouldn't be a good summary without me discussing what new bleeding-edge technology was right around the corner. EVDO Rev B, allowing for at least 4.9 Mbps/1.8 Mbps speeds, has been deployed in a few places in Asia, but given how backward North America tends to be in technology adoption, won't be in the United States anytime soon. WiMAX, a 4th generation cellular technology allowing for speeds of at least 10 Mbps, will probably take the place of EVDO. Sprint is the only major provider dedicated to building a WiMAX network, with plans to begin deployment at the end of 2007.

Some external links with good information:

• EVDOforums.com: Forum dedicated to EVDO. Sponsored by an online store Booster-Antenna.com, which specializes in EVDO technologies, offers much better prices than provider's retail stores. I maintain a thread about EVDO on Linux, with community-provided configurations and vignettes.
• EVDO on Wikipedia
• Comparison of wireless data standards on Wikipedia

Columbia University's Medical Center, like many university campuses, has many WiFi access points. To meet HIPAA privacy regulations all their wireless networks require use of VPNs or sophisticated encryption protocols.

Connecting to their athens wireless network, which uses IEEE-802.1x authentication, is a little non-obvious with Linux, but is possible given your wireless card supports WPA and works with wpa_supplicant.

To save the many weeks I spent fiddling, the magic wpa_supplicant.conf stanza that works for me:

Replace foo with your Columbia University UNI and bar with your password.

T-Mobile's WiFi Hotspot service, thankfully, forgoes a proprietary authentication mechanism for a solution that while cross platform (i.e. it works with Linux), can be extremely annoying. On opening a web browser and attempting to go to any website, you're required to login on an SSL-protected website with your account username and password before you can use the connection. If your web browser automatically tries to open many pages on startup, such as when you're using the Session Saving extension for Firefox, you get T-Mobile's Hotspot login page in every tab--extremely annoying!

I've written a small Python script that can login programatically without use of a web browser.