Advanced receivers - hearing aids for data cards

There’s a hot topic in the world of HSDPA at the moment – advanced receivers. We’re going to hear more about these technologies in 2007 – they’re enhancements that data card manufactures are going to be making to their devices to squeeze out as much speed as possible. Here’s the two to watch this year:

Equalisers – listen carefully, I'll say this only once
An equaliser is an extra bit of software that runs on the device and helps to cancel out interference from other devices and cells in the network. The result in an increase in your data throughput. You’ll get the majority of the benefit from an equaliser when you’re in good coverage – so it makes a good service even better. As you move into poorer coverage, an equaliser offers very little benefit.

Receive diversity – twice the fun
This is where you see the much of the benefit from advanced receivers. This is a difference in hardware – it means your device has got two antennas and receivers, which improves performance across all coverage conditions, including in poorer coverage areas.

To put it into context, here’s an idea of the speeds you can expect with HSDPA:

1.8Mbps device
1.4Mbps in good conditions
1.0Mbps in typical conditions
400Kbps in poor conditions
These are the fastest speeds you’ll get in the UK at the moment

3.6Mbps device + equaliser
3.4Mbps in good conditions
2.1Mbps in typical conditions
400Kbps in poor conditions
Here you see an increase in speed in good/typical conditions, but nothing in poorer areas.

7.2Mbps device + equaliser, no receive diversity
4.0Mbps in good conditions
2.1Mbps in typical conditions
400Kbps in poor conditions
As you can see, there’s very little point in having a 7.2Mbps device unless you’ve got receive diversity.

7.2Mbps device + equaliser and receive diversity
7.1Mbps in good conditions
3.5Mbps in typical conditions
800Kbps in poor conditions
And here’s the difference with receive diversity – all round improvements in all coverage types.

So it’s a no-brainer – if you want to hit those higher data rates you’re gonna need the right kit for the job. If you’re thinking of buying a 7.2Mbps capable device, make sure it’s got receive diversity otherwise you won’t have much chance of getting above 2Mbps. Oh, plus you'll need to find a fast network - everyone here in the UK is running at 1.8Mbps max...