Bell Canada says extra charges are needed to discourage heavy downloaders from causing congestion on its network. (Ryan Remiorz/Canadian Press)

The CRTC is holding off on implementing an order that would allow Bell Canada to charge smaller internet service providers based on how much their customers download each month.

The regulator on Wednesday said it needs more time to consider comments submitted by Bell, MTS Allstream and a group of smaller ISPs on its earlier provisional ruling, made in August. That order was supposed to take effect Nov. 10, but will be delayed until the regulator has had a chance to assess all the comments.

The CRTC did not say when it expects to make a final decision.

Under Bell's proposed usage-based billing system, ISPs that rent portions of its network to provide their own services — which includes smaller companies such as TekSavvy and Acanac — would face additional charges for offering plans above 60 gigabytes a month.

Bell says the system is necessary to discourage heavy downloaders, many of whom are customers of smaller ISPs, from abusing its network and slowing it down for all users.

MTS Allstream and the smaller ISPs say Bell wants to "double-dip," or charge them once for accessing the network and again for using it.

They also say Bell is trying to remove their main ability to differentiate services, particularly on the residential side of the business. Many small ISPs typically offer customers monthly download limits in the hundreds of gigabytes, while Bell's most popular plan allows for only 50 gigabytes. Usage-based billing would make it prohibitively expensive to offer those big download plans, the ISPs say, which will turn them into "mini-Bells."

MTS and Acanac, a small Toronto-based ISP, have also asked the Federal Court of Appeal to overturn the CRTC's decision. That appeal is still before the courts.

The decision comes a week after the CRTC was criticized by a Harvard University study for more than a decade of "half-hearted" enforcement of open-access rules. Canada has long required large companies such as Bell to provide access to their infrastructure to third parties in order to boost broadband competition, but the CRTC has allowed network owners to set high rental rates, which has scared many companies off from taking advantage.

That has resulted in Canada lagging the rest of the developed world in broadband speeds and prices, the study said.

The ruling also comes the same day as the CRTC's findings on a net neutrality hearing held this summer.

The regulator on Wednesday announced that ISPs would only be able to use network management measures such as traffic shaping and slowing if economic measures, such as infrastructure investment and usage limits, failed to curtail congestion.