VoIP and IM applications experienced 47% growth during the half. The majority of VoIP traffic on mobile networks is generated over IM applications. Undisputed market leader Skype accounted for 77% of the global VoIP bandwidth during H2. Competitors Yahoo Messenger, GoogleTalk and WindowsLive lagged distantly behind, accounting for just 5% each of the bandwidth.
The most popular IM application was Yahoo Messenger. Together with Windows Live, they account for 56% of global IM bandwidth. Chinese-language IM application QQ was third with 16% of the bandwidth.
Another leading cause for growth in bandwidth consumption is the popularity of social networking sites. Facebook traffic, for instance, grew nearly 180% worldwide - and 280% in Asia - during H2. Facebook estimates that over 65 million active users access the site via mobile devices.
"Mobile broadband and social networking seem to be a match made in heaven - people get access to what they want - and who they want - 24-7," Gordon said.
But taking a look at a breakdown of the average cell compared to the top 5% of congested cells, it becomes clear that heavy users are skewing the results.
"The single largest factor leading to cell congestion remains P2P, which accounted for 34% of bandwidth utilization in the top 5% of utilized cells," the report said. "This is nearly three times P2P's bandwidth utilization of 12% in the average cell."
HTTP browsing remains the most popular application on the average cell, consuming 33% of bandwidth compared to just 17% in the most congested cells. Allot said that browsing is much higher in the average cells because it is an internationally popular way to use a mobile broadband network.
Ovum's Burley added that P2P applications can be disastrous for mobile network performance. "P2P applications tend to use up all available bandwidth," he said. "With this potentially leading to congestion, some operators have looked at de-prioritizing P2P.
"Although this may have regulatory and customer implications in some geographies, some operators have implemented solutions with scope to do so in their terms and conditions."
Hong Kong operator CSL, for example, in February decided to throttle high-bandwidth file-sharers on its Next G HSPA+ network. The operator said that 5% of its customers account for more than 50% of the bandwidth consumed on its network.