It’s only been a couple of weeks since we last looked at mobile broadband deals, but a few providers have already changed their tariffs in the meantime. O2 has finally introduced two consumer-friendly deals (more details in the original feature), and both Vodafone and T-Mobile have rolled out new modems in readiness for their 7.2Mbit/s HSDPA services. So, we’ve taken a look at both.

The tariffs may differ, but both Vodafone and T-Mobile use the same Huawei HSDPA USB Stick modem, albeit in different liveries. It’s a little chunkier than a typical USB flash drive, but still highly pocketable.

Both the Vodafone Mobile Connect and T-Mobile Web ‘n’ Walk Stick III put the SIM card in a slot just above the USB plug. It clips securely in place, but its placement also means that it can’t pop out when the cap is on, or the modem plugged into a USB port. The Vodafone modem’s cap is also tethered to the modem by a short length of string – a neat touch that should stop the cap from getting lost.

Installation of both modems is both quick and easy – the drivers are stored in on-board flash memory and installation begins as soon as the modem is plugged in. MacOS X 10.3.X drivers are included for both modems too, and both even come with a USB extender cable so that they can be plugged into the Apple MacBook Air’s fiddly USB port.

Software installed, both modems then automatically trigger the mobile connection application when they’re plugged in. Vodafone's application, Mobile Connect Lite, is pretty lightweight and it just provides a thumbnail view of key bits of inforamtion.

The main window shows only data use for that particular online session, but there is a separate usage screen that shows a cumulative total. Vodafone’s mobile broadband tariff’s all have a 3Gb monthly limit, but you’ll need to manually configure the Vodafone Mobile Connect Lite application to reflect this.

Unfortunately, the cumulative data figure is reset when the application exits (which happens whenever the modem is disconnected), so there’s no easy to monitor data usage. This is a particular problem with Vodafone as not only is its excess use charge is £15 per gigabyte, but it also bills by the byte – so you’ll pay £15 even if you download just one extra byte at 23:59:59 on the last day of the month.

T-Mobile’s Web ‘n’ Walk Stick Manager is rather more comprehensive in its data monitoring and while it lacks an option to warn when you approach a certain download amount (not much of an issue, since T-Mobile doesn’t charge for excess data), it does remember figures between sessions.

In theory, HSDPA networks are capable of delivering download speeds of anything up to 7.2Mbit/s, but it should come as no surprise to learn that all manner of factors can adversely affect this theoretical maximum. In fact, a better way of thinking about mobile broadband speeds is that the higher the figure quoted by the provider in their marketing materials, the less likely you are to achieve it.

T-Mobile wisely sticks to “high speed internet” for the USB Stick III and makes no mention of an actual download speed – though you might be led to expect 7.2Mbit/s by its use of “HSDPA” on the modem’s information page. In reality, T-Mobile’s 7.2Mbit/s network won’t be up and running until June at the earliest and when pressed, it stated that 3.6Mbit/s would be the best users could expect until then – though this figure isn’t  mentioned anywhere online.

Vodafone, on the other hand, boldly states that its mobile broadband network offers “up to 7.2Mbit/s" download speeds – as long as you’re in one of the few areas the network currently covers. Otherwise, you’re stuck with 1.8Mbit/s.