UMA Revisited

My new BlackBerry Curve 8900 arrived surprisingly last Tuesday. I had been told by the Orange sales representative before, it could have taken a week, but in this case the week was only two days. First impressions - the best phone ever, surely the Bold 9000 beater. Yes it does not have 3G, but who cares :) ???.

At the time I write this (Wednesday morning, as Sunday is planned for joyful snowboarding in Austrian Alps) the BlackBerry services are not yet fully functional, so I cannot comment if The Switch from T-Mobile to Orange has been successful, but one thing I tried was UMA.

I posted on UMA before, as I has been one of technologies / services I consider very smart. In short: it allows to talk via Wi-Fi. Elaborating a little more on the subject, UMA is a solution implemented by a MNO (Mobile Network Operator), that allows certain (UMA compliant) mobile phones to log on to the MNO's network over Wi-Fi. So instead of connecting to the MNO's base station, the phone uses Wi-Fi access point and fixed Internet broadband connection to create a secure tunnel to the MNO's network. It is very different at the physical level, compared to traditional GSM or 3G/UMTS, but is virtually indistinguishable at the logical level. UMA-capable phone logged via local Wi-Fi access point to the home network works as usual. It rings, receives calls, allows you to dial and connect the same way as it was using GSM/3G radio. Even data services work in the same fashion, mimicking packet data sessions to MNO's APNs, you normally use.

On lightly loaded local networks UMA does not require any setup. Just let the phone connect to the local access point (give it a password and that is it). On networks that are more utilized, you may experience some degradation in call quality. This is where QOS (Quality Of Service) policy may be needed. Imagine you are at home, and your home's Wi-Fi connects to a router than to a DSL modem and to your local ISP (Internet Service Provider). Your DSL is likely 1Mb/s or faster. As this probably is A-DSL (asymmetric), your uplink is slower than the downlink, so may be in the range of 512Kb/s or better. This is still plenty of bandwidth. Voice call plus all signaling around it should never exceed 100Kb/s, so the pipe is fat enough. But once you start downloading something from the Internet, or - better (or worse) - uploading some pretty heavy files, like your recent digital photo session from a camera up to the Flickr, you may have difficulties having a conversation over UMA. This is because large Internet packets flood the pipe and the tiny voice packets are stuck in this traffic jam. To resolve this problem you will need a router capable of prioritizing your voice traffic. This may not be an issue at home, as high traffic bursts are not that frequent, but consider one for business environment.

Apart from the above mentioned potential QOS issue, UMA is a fantastic solution. It frees the MNOs from taking an extra load on their network. It connects to the home network all those terminals usually wandering into the costly areas of national roaming partners. It gives coverage in all those places coverage is missing - as is the case in my home, where I could talk leaning out of my window, catching the stray GSM signals, but yesterday I could walk anywhere inside my house and have an uninterrupted conversation, thanks to UMA.

The problem with UMA has been the classic chicken - and - egg problem. Not many MNOs decided to implement this technology (T-Mobile USA pioneered it in the US while Orange seems to be the leader on the Old Continent). At the same time just a few dull handsets supported UMA. Last December, when I decided to go for BlackBerry, I was not aware BlackBerries supported UMA. And today this has been one of the key factors behind my decision to switch to Orange. UMA now gives me now true in-house mobility (something only a few people living on the edge of cellular coverage can understand). UMA calls are less expensive too. And when roaming abroad, if I succeed connecting my phone to the local hotel's Wi-Fi, I am not roaming any more... All calls even in Russia or Peru are local over UMA, so this is an advantage for frequent travelers watching their phone bills...

With more and more handsets supporting UMA (iPhone should have it, don't you think?), this technology can really fly. It should also be a huge cost saver for new challenger MNO's, who live on national roaming.