Jason’s .plan

Some folks hate to be offline, and some folks can't afford to be. I suppose I fit somewhere in between. About a month ago, I realized I was going to be doing some significant traveling…probably nowhere near a decent WiFi access point. Thus arose the question…how do you connect back to the office regardless of where your derrière happens to be? There were only a couple of minor requirements:

• (Good) National 3G (U.S.A.) coverage
• Minimum top end throughput around 1Mb/s
• ExpressCard form factor (nothing sexier than a wrist-sized dongle cantilevered off your USB port)
• Support for Mac OS X

Folks that know me probably are stunned at the last one. As of April 29th I kicked the Dell habit. My regular target of abuse is now a MacBook Pro. But that's a whole other story…

Anywho, those req's really narrowed it down to two players: AT&T and Verizon. Both offer national 3G access at speeds of 1Mb/s or greater. But they take two different approaches to it…

HSPA (High Speed Packet Access)

High Speed Packet Access is really the joining of two different 3G GSM protocols: HSDPA and HSUPA (the D and the U are “downlink” and “uplink” respectively). On AT&T's network, HSPA should give you average speeds around 1.8 Mb/s down and 800 Kb/s up. My experience has been that this is true across their network…as long as you can get a 3G signal. In fact, in some areas (LA and San Antonio) it wasn't uncommon for me to get around 2.2-2.5 Mb/s down. With tower upgrades coming early next year, the downlink speed should boost further to about 7.2 Mb/s. Overall, pretty darn good for no leash. Factor in the fact that HSPA is a 3G GSM standard widely deployed across Europe/Japan and suddenly you've got a great data solution worldwide (an issue given some upcoming trips). Oh, I forgot to mention…some places in Europe have already deployed 14.4Mb/s HSDPA (HSUPA deployment is somewhat spottier).

Compared to EV-DO, HSPA also has some design advantages. For example, both EV-DO and HSPA time slice transmission to connected clients, but HSPA can transmit to 10 clients in single time slice, whereas EV-DO can only transmit to one client per time slice. Also, HSPA towers possess the capability to figure out which clients have the best signal quality and will transfer bandwidth capacity from clients who can't use it (bad signal) to clients that can (excellent signal). Of course, even with all of its advantages, the HSPA network is being run by AT&T…and they could screw up implementation of a PB&J sandwich…

EV-DO (EVolution – Data Optimized)

Like HSPA, EV-DO is a CDMA-based 3G protocol. Unlike HSPA however, it is not a GSM body standard and is instead the successor to CDMA2000. So, outside of the U.S.A, Korea, areas of Japan and piroshki stands in the former Soviet-bloc you're pretty much out of luck for access. However, it does provide 1Mb/s speeds regularly. Upload speeds are in the 200-500 Kb/s range.

With that brief understanding, I motored down to the Verizon and AT&T stores and picked up service with both companies (AT&T and Verizon have 30-day refund and new service cancellation policies).

Behind door number 1…

For a couple of years now, I've heard phenomenal things about Verizon's BroadbandAccess (EV-DO) service. People seemed to rave about it's coverage and reliability…and they're right. Verizon's biggest plus is it's consistency. It may not be as fast or have as low latency when AT&T is on the ball, but they'll deliver the same service levels every time you power up. I don't care if I was in Boise, LA, or San Antonio, Verizon delivered 800-1000 Kb/s throughput and 230ms latency like clockwork. Sometimes it was a bit better or a bit worse, but only by about 10% (exception was the trip up the coast to Malibu where Verizon dropped down to 2.5G service and AT&T was nowhere to be seen).

The other nice thing about Verizon is the Novatel V740 ExpressCard. It has excellent support in OS X. Pop it in and OS X's built-in WWAN manager configures the card, activates it with Verizon and away you go. No special software to install. You even get a nice little signal strength meter on the task bar (yeah…yeah…taskbar…Windows habits die hard ).

The gal you really wanna take home to Mom…

I wanted AT&T to be the best…honest. I'm a current AT&T Wireless voice customer and love the phones, the stores and the service. However, 3G service with AT&T lacks Verizon's consistency. Initially, 3G coverage could be hit and miss when I started 4 weeks ago. However, their big push for blanket 3G coverage in advance of the 3G iPhone launch has improved the 3G network dramatically in the last week. Although the coverage is spot on now, the service level is not in terms of latency. Throughput however is phenomenal. 1500-1800 Kb/s downlink speeds over 90% of the time, with solid 2200-2500 Kb/s in areas with the latest tower gear. So for the majority of applications, AT&T LaptopConnect is a superior solution to Verizon. But…not for me.

Quite a bit of the remote work I do involves either SSH or Windows Remote Desktop over VPN. There's few things more annoying than mistyping a command and waiting for the refresh to catch up so you can go correct it. As a result, better latency means a happier camper 'round these parts. That's not to say that AT&T's latency is awful. In fact, it's better than Verizon about 80% of the time when you measure it. So why am I complaining about it? Well, 150ms latency is only good if it stays at 150ms. AT&T's deployment of HSPA causes latency spikes regularly, particularly under load. As a result, I started doing an combo test on both services…load a YouTube video and concurrently check the ping over a VPN tunnel. If you try it, you'll see both Verizon and AT&T's latency spike dramatically. Hmm..you're probably thinking, “so AT&T is better than Verizon both with and without heavy load…why won't you say its better?”. Because, it doesn't feel faster. It was really hard to put a metric on this, because while the measurements were better on AT&T, the lag while typing on an SSH connection always felt a little (to a lot) bit slower. In fact, I kept reminding myself that this had to be in my head, because the ping measurements were better than Verizon. Then while in San Antonio I tried using Skype.

San Antonio expectedly has the best coverage of any AT&T area I've been in. Consistent throughput above 2200 Kb/s and latency below 150ms. So imagine my surprise when my SSH sessions seemed laggy, and the Skype calls would start great and then break down within about 3-4 minutes. You could hear the person on the other end of the call fine, but they started having issues hearing me and my video would lock up for them. If you turn the video off it'd buy you another 4-5 minutes before the call went haywire. So back in went the Verizon card. Bang. Perfect SSH sessions. Crystal clear call quality on Skype…and the folks on the other end said not only was the video smooth but the quality of the picture was better (Skype must adjust video quality based on connection quality). A 45-minute Skype call completed with no audio or video issues on Verizon.

I tried the Skype exercise about 3-4 times over a 48-hour period with the same results. Every time I'd give AT&T a shot, and every time I'd have to drop in the Verizon card to complete a decent conversation. This bodes not well for the rumor that the 3G iPhone will take advantage of HSUPA for video conferencing. On the positive side, those consistent 2200 Kb/s AT&T downlink speeds meant I was able to suck down the OS X 10.5.3 system update (420MB) in about 30 minutes (~1500 Kb/s sustained average).

The other major issue with AT&T is the Option GT Ultra Express card. On the positive side, it supports HSUPA so you can take advantage of fast uplink speeds. Unfortunately, it isn't supported natively by the OS X WWAN subsystem (unlike it's unavailable predecessor, the Option GT 3.6 Express which is natively supported). So you have to install Option's GlobeTrotter software, which isn't a slick as the native support and frankly feels poorly built. A lot of folks on the Apple and AT&T forums have also complained about GlobeTrotter frequently crashing for them. To some degree I suspect the inconsistent performance I get from AT&T (despite the metrics) might be due to GlobeTrotter. There's also Launch2Net by NovaMedia, which provides 3rd party drivers for the GT Ultra Express. Still not native, and amazingly Launch2Net axes the native WWAN utilities that the Verizon card leverages (Launch2Net got uninstalled faster than Vista on a 286). Supposedly, OS X 10.5.3 was going to include native support for the GT Ultra Express, but as of 10.5.3's release yesterday…no dice.

Lastly, there's price. Both AT&T and Verizon charge $60/month. However, AT&T's service is unlimited where Verizon's service is 5GB/month (and $0.49/MB over that).

End of the road…

So where does that leave us? If you need reliable latency and pretty darn good speed, Verizon is your best bet in my opinion. On the other hand, if the majority of your remote work involves the web, e-mail or anything else that's not latency sensitive, AT&T is far superior and will allow global roaming. Frankly, I'm kind of anxious to hear from someone who has the GT Ultra Express on a Windows machine to find out if the inconsistent performance I experienced was specific to GlobeTrotter for Mac. Personally, I'm going to keep both services. There were a handful of times that Verizon's latency was abysmal, but AT&T's was great. Enough that I realized in an emergency I'd really need to have the option of either service.

Here's hoping AT&T's 3G latency improves…and that Apple gets with the program and includes native support for the Option GT Ultra Express…the 3G ExpressCard of choice for Apple's carrier of choice. Sorry that this post blathered on a bit long. I hope this saves other folks from having to do this much evaluation legwork.

(Here is the XLS sheet with observed metrics for both services: AT&T vs. Verizon Benchmarks )