The connection conundrum: 3G or Wi-Fi?

The need for speed
Ok, so what about the all important speed? Vodafone's 3G network promises a maximum down-speed connection of 384 kilobits per second (Kbps), or 48 kilobytes of data per second (KB/s). In testing, we regularly achieved speeds of around 264Kbps (33KB/s, or around 2MB a minute), with top speeds of 360Kbps (45KB/s).

On paper, Wi-Fi can leave 3G in the dust. An 802.11b (the slowest Wi-Fi protocol and the one most commonly used by Wi-Fi operators today) network offers a theoretical maximum speed of 11 Megabits per second (Mbps), although only about 5 Mbps is actually possible. In practice, however, the top speed at a hot spot depends on the speed of the backhaul broadband connection, which could be anything from 512Kbps to 2Mbps.

None of these figures tell the whole story, though. Both 3G and Wi-Fi are contended services, so everyone within a hot spot or a cell has to share the available bandwidth, says Niall Murphy, chief technical officer for Wi-Fi operator The Cloud.

"If there are ten people in one 3G cell, all trying to download a 5MB MP3 file, then they'll see their maximum speed drop to something like 60 kilobits per second," he explains

The same theory applies to a Wi-Fi hot spot but in practice, when ZDNet UK tested a series of commercial Wi-Fi sites around London, we encountered very few other users and usually enjoyed the maximum bandwidth.

The speed issue isn't black and white but what is clear is that Vodafone do give the option of dropping down to GPRS if 3G isn't available, so employees who are entrusted with a Mobile Connect card can always connect in some shape or form anywhere in the UK. Wi-Fi users meanwhile may find the local Starbucks has lost its connectivity, and that the staff don't know how to get it back

The price is right?
Rock and hard place best describes the pricing alternatives at the moment for IT professionals weighing up the options for both technologies. Wi-Fi pricing has been too high, say analysts, pointing to £6 for an hour's access, or £85 per month for unlimited access to BT Openzone, for example.

The Cloud's Murphy, whose company resells access to its network to other operators, such as Openzone, believes Wi-Fi pricing needs to be reformed and that 3G could be the catalyst. He thinks 3G will put pressure on operators to move to a post-pay environment, in which customers are charged for actual usage, rather than today's pre-pay model, where payment is made up front for a fixed period of access that is often more than required.

"When people have to pay for access time that they may not use, there's a perception that they don't get value. Frankly, I'm amazed that people put up with it. It must be an early-adopter issue," says Murphy.

Vodafone is expected to launch a Wi-Fi component to its 3G service later this year. Stonadge says this will help Vodafone to offer a "complete suite of core solutions" to its customers. It's not yet clear how this will be priced, but customers will probably be charged using the same pre-pay system that Murphy says needs reform.

Per-minute Wi-Fi charging could be introduced if the market demanded it, says Stonadge. "We've yet to fix the pricing. It's more likely that we'll charge by the session, which could be 30 minutes or an hour, because that's what is in existence today."

Vodafone's 3G pricing, based on the amount of data that the user sends and receives, has also caused some concern. The top tariff for power users offers 500MB of traffic for £85 plus VAT per month, which works out at more than a grand per year per user. "The feeling we've had is that the ability to have true mobile broadband provides enormous value," says Stonadge.

But the UK pricing isn't the whole story. The massive cost of roaming onto one of Vodafone's 3G networks in continental Europe could deter a lot of potential users, says analyst Bubley.