Vodacom has defended its decision to throttle the download speeds of BlackBerry Internet Service (BIS) users who download more than 100MB/month, saying some users were exceeding 100GB of data in a 30-day period using BlackBerry smartphones.

The company says it will move customers who use more than 100MB/month from its higher-speed 3G network to a far slower 2G service, but emphasises consumers will not be bandwidth capped. It found that “more than 95% of BlackBerry data usage was attributable to less than 5% of users”.

Vodacom chief technology officer Andries Delport says the company has users who exceed 100GB on their BlackBerrys on a monthly basis. “We had a documented case of a user exceeding the 310GB level in a month,” Delport says, adding that fewer than 5% of users consume more than 100MB/month.

The BIS service allows unlimited on-device e-mail and browsing for a fixed monthly fee. This has proved popular among consumers, especially the youth who use their BlackBerrys constantly for instant messaging and Facebook. It’s not meant as a facility for downloading large media files.

Explaining how users have circumvented the system, Delport says “certain Internet sites allow users to download video clips using progressive download mechanisms”.

“Over and above this, there is software that allows the tethering of BlackBerry devices onto computers, which exacerbates the situation,” he says.

He explains that the 100MB/month threshold was reached by considering the average usage of the “vast majority of BlackBerry users on our network”.

“What also has to be borne in mind is the fact that BlackBerry traffic is compressed by a factor between two and four times, depending on the type of traffic,” Delport says. “Thus, the actual data volume allocated to BlackBerry users would vary between at least 200MB and at the most 400MB per user per month, depending on the type of traffic.”

He says Vodacom expects other operators will follow suit with similar throttling measures to prevent abuse. “There is always the danger of losing customers to other operators, but we have taken this decision in order to provide our customers with superior experience and we are certain that the vast majority of them that do not abuse the service will appreciate this.” — Duncan McLeod, TechCentral