I wrote about my experiences with 3.5G - or HSPA, mobile broadband a couple of days ago. I have been using it for almost a year in Singapore.
The last time round, I wrote on my general experiences with its suitability under various usage scenarios. Today, I want to share some of the downsides I experienced that your provider probably won't tell you about.
HSPA is fast. OK, make that very fast. No doubt about it, the blazing speed of this technology actually makes downloading multi-megabyte files on the move practical -- assuming that your provider offers an unlimited data plan that is.
However, as fast as HSPA is, don't expect to get anything near the maximum theoretical speed. Ever.
It's a bit like wireless LAN actually. Remember all those advertising illustrations about 802.11g and its various "enhanced" variants? I personally have problems maintaining my laptop's wireless connect to my router in the afternoons, where an average of five other neighbors - and their WLANs pop up. The mind-boggling clincher here is that my wireless network point is just 10 meters down the hall!
I mean, do you seriously believe you can get 7.2 Mbps? Sorry mate, that's the theoretical maximum speed, so dream on.
The reliability of data transfer is definitely lower than that of a dedicated wired Internet connection. There are occasions where web pages simply freeze halfway through loading as some of the requests time out.
I had the chance to speak to a senior engineer from a local Telco in Singapore. According to him, the data and voice portions of the network are separate entities from a technical perspective. Hence it's entirely possible for the data part of the network to be down while the voice portion - where the Telco is likely to be bound legally to maintain a minimum uptime - remains fully operational.
As you can see, the reliability of the HSPA data network doesn't equal the reliability of voice over either a 2G or 3G network.
I guess that's another spanner in the works for those of you intending to use the VoIP functionality incorporated in Windows Mobile 6.
All 3G phones are able to switch to 2G should the 3G network be unavailable. As such, unless mandated, providers with a 2G infrastructure already in place have little incentive to ensure that all coverage areas are 3G enabled.
From experience, the underground subway stations in Singapore only offer 2G signals - at least for the Telco that I subscribe to. It's probably not a problem to most folks, but blind spots do exist in the 3G coverage. In the context of 3.5G, that means that the HSPA experience will inevitably be poorer than that of GPRS.
Transmitting on a 3G-network consumes power at an astounding rate. Ditto to 3.5G. If you intend to download the latest Ubuntu ISO over your HSPA data modem, be sure to plug it into an AC socket.
And oh yes, the data modem will get rather warm quite quickly too.