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Christian Nimsky's Weblog

T-Mobile Blackberry Curve

Christian Nimsky


Usually I’m the kind of guy that tracks and buys the latest gadget.  This has been true for celphones for a number of years, but recently I’ve become jaded.  The iPhone came and went and I didn’t bat an eye.  Two weeks ago I found myself replacing my celphone after my trusty T-Mobile Blackberry Pearl suffered from acute gravity-induced shock syndrome, also known as a hard drop onto the sidewalk.  What I found when I went to the T-Mobile store was truly cool.

The Blackberry Curve is one of those “skinny Blackberries” that is roughly modeled after the 8800 series which came out right after the Pearl.  I had preferred the Pearl because the 8800 was well, too long and kind of square-ish.   Yet when I compared my dead Pearl to the Curve the Curve had the same length and was just a smidge wider than the Pearl.   It has a fully QWERTY keyboard which is nice, no glued-on buttons (thank you, RIM!) and most importantly, it has a Wi-Fi chipset and can use T-Mobile’s UMA (Unlicensed Mobile Access) service at any 802.11 broadband connection that supports IPSec pass-through and WMM (wireless multimedia).

What does UMA do?  Well, when the phone finds a Wi-Fi access point it can log into (either an open one, a T-Mobile Hotspot which can be found at many Starbucks, or one that you manually configure) it compares the T-Mobile cellular signal to the Wi-Fi signal and if the Wi-Fi signal is strong, it switches to Wi-Fi.  The phone then uses Wi-Fi for Blackberry data transfer (e.g. email), SMS and, yes, also voice.  And it can switch back and forth between Wi-Fi and T-Mobile’s EDGE cellular service in mid-conversation without you noticing at all, unless you are watching the phone’s screen.  How does this get charged you ask?  When you subscribe to T-Mobile’s Hotspot @Home service for $9/month, you get unlimited calls to US-based numbers.  For people like me that work extensively from their home office with poor T-Mobile EDGE signal strength, this is a pretty neat plan.

Is there a catch?  Well, the service is new and a lot of people are unfamiliar with it, including some technical support people for companies that make Wi-Fi access points (looking at you, Apple).  The two protocols I mentioned above (IPSec and WMM) are key requirements however, as the phone is basically establishing a VPN-like connection to  T-Mobile’s servers and then passing voice packets through the WMM protocol.  If your router / access point doesn’t allow IPSec pass through - though most do - T-Mobile’s UMA won’t work at all.  If your access point doesn’t support WMM (and the power-saving features that go with it), you can use UMA but you will chew through your battery very quickly and you may drop calls.  I’ve confirmed after hours on tech support and various forums, and with my own testing on four different wireless routers.  Most broadband routers can support those two protocols but if yours doesn’t, you’re out of luck.   

My main access point at home didn’t (I will post later on Apple’s Airport Extreme wireless access point/router and why I am quite disappointed with Apple on this front) however you can get a T-Mobile branded D-Link or Linksys router for something like $50 with a rebate equivalent to the purchase price so worst case you can set up a 2nd wireless access point just for your phone.

Setting up a 2nd wireless access point is precisely what I did (an old Linksys WRT-54GS running DD-WRT) and things are working relatively well so far.  Throughout this post I might have sounded like a T-Mobile salesman but I have found one issue: My house isn’t a McMansion by any stretch of the definition but it is large enough to require either a really powerful 802.11n router to cover it all (which is why I bought the Apple Airport Extreme) or multiple 802.11g access points which means - you guessed it - roaming between WiFi access points.  My tests thus far on the Curve show that it can jump WiFi access points sometimes, but not consistently consistently (see update at the bottom of this post) if you get the upgrade to the latest firmware (  A call I put into T-Mobile yielded a 3rd level technical support rep who basically told me that I was working beyond the envelope of technology they can support.  Ummm, what if I were an enterprise customer covering 30,000 square feet of office space?

In fairness to T-Mobile, who has been really nice to me thus far, I can’t jump to a conclusion based on this one technical support rep that they won’t support enterprise customers with big wireless networks spanning dozen of access points, but Wi-Fi access point handover is something I would test extensively if I were thinking about buying a couple hundred Blackberry Curves for my employees.

But for the individual user, it works pretty well.  As I write this, I am at the Starbucks in LAX getting ready to hop on yet-another-business-trip and my Blackberry Curve is receiving calls and e-mails over Wi-Fi through T-Mobile’s Hotspot.  I didn’t have to push so much as one button on the device to get it to do that. 

I’ve noticed a lot of business associates getting “iPhone envy” over the past few weeks - many have bought iPhones by now - and at the risk of not being part of the “cool crowd” I will admit that I  just don’t get it and I’m generally an Apple fan.  I might not be able to zoom pictures with my fingertips or flip album covers while waiting for my flight, but I’d rather have this e-mail machine over an iPhone any day.

Update 10/26/2007: I downloaded the latest firmware ( from T-Mobile’s site and I can say from my brief testing that UMA voice quality has improved, Wi-Fi data access speeds seem a little faster, and the 8820 can now hop between the various access points around my house during a call without a problem.  Note that to achieve the seamless access point hopping my access points share the same SSID and are spread 4 channels apart.  To give the device a single constant the access points are connected to a single DHCP server and firewall.   I still wish the T-Mobile rep could have told me, “hey we have an update coming out in several days that will fix this so hang tight…”