Vodafone makes more out of less with compression technology

By PETER GRIFFIN

Vodafone is seeking to make more out of the less as it becomes the latest communications company to employ compression technology to speed up data downloads.

The mobile operator is using optimisation software from US company Byte Mobile to improve data transfer speeds over its relatively low-speed GPRS network as it launches a new data product aimed at business users.

The Mobile Connect card allows users to slot their Vodafone SIM card into a PC Card adapter and use it as a wireless modem for their computer operating over Vodafone's GPRS network. The cards will sell for $749 with data charges ranging from $5 per megabyte (MB) to $50 for 80MB. Casual usage is charged at 10c per 10 kilobytes of data transfer.

At the same time, Vodafone is activating a server on its network housing Byte mobile's optimisation software, which according to the company serves three purposes - "classification, data reductions and protocol acceleration".

"While server optimization alone can achieve great performance, even more impressive performance is possible through a full client-server implementation," said Byte Mobile.

That involved the user having client software resident on their system - the software is bundled with Mobile Connect and available for the Windows operating systems.

Internet providers Slingshot and Quicksilver recently began using compression software to boost transfer speeds for its dial-up customers. Larger internet providers are understood to be considering implementing similar technology.

Vodafone business mobile specialist Tim Hayward, said the technology would work best for web page browsing, with pages loading 20 - 40 per cent faster. The software delivered webpage images and graphics in low-resolutoin format by default to save time and data. Users could refresh pressing "ctrl + F5" to reload the page at a higher resolution - but face a longer wait and pay more. Graphics in the Flash and Java standards were already heavily compressed and would not be optimised.

"The speed will depend on the content of the webpage. Sites heavy on Flash-type graphics will be slower to come up," said Haywood.

And files downloaded more speedily via a web browser would not experience the same speed increase if sent via e-mail.

"If the same file was sent as an e-mail attachment them it would be MIME encoded so would compress to a different ratio, probably not quite as high as this, but still significant," said Hayward.

In a demonstration for the Herald, Hayward notched up 1.45MB in data transfers.

A speed test of downloading a JPEG picture file showed data throughput of around 150kbps and basic connection speed of 40 - 45kbps, suggesting the file was compressed by a factor of 3-4 times.

Hayward estimated 50 - 75 per cent more data was actually received, leading to equivalent cost savings as less data was being transferred.

The compression ratios are best for general surfing of web pages - text/HTML (75%), Microsoft World files (50%), Microsoft Powerpoint file (60%), animated GIF file (25%), JPEG file (65%), Acrobat PDF (25%).

The optimisation would not work on virtual private networking traffic where encrypted data traffic passes across a company network via the internet.

Hayward said mobile workforces send e-mail and accessing the internet on the move stood to make large savings on their GPRS data bills. But while the optimisation software squeezed faster transfers out of existing technologies, mobile had its inherent weaknesses.

"Latency across mobile networks is a lot higher [than fixed networks], around 400 to 900 milliseconds. And the raw bandwidth is still the same, it hasn't increased".