Mobile operators will have to upgrade the backhaul capacities of their networks to provide high-bandwidth 3G services, comms experts warned today.

"In order for mobile operators to deliver the expected bandwidth of 3G and newer technologies, backhaul is critical," said ABI Research senior analyst Nadine Manjaro.

"Backhaul is a major contributor to network performance and cost, and operators should design their networks to meet peak traffic demand, not just average usage levels."

ABI Research cited service provider testing showing that end user data rates and the number of active subscribers served per sector vary greatly based on the backhaul technology employed.

For example, as T1 reaches near capacity, the network performance degrades by over 40 per cent.

In a recent study, ABI Research forecasts global capital expenditure for backhaul to increase from $14bn in 2007 to $23bn in 2012.

Operating expenditure is also expected to rise from $1bn to $6bn during the same period.

"As a result, operators should be focused on solutions that will meet their performance requirements with the minimum capital and operating expenditure," Manjaro added.

ABI Research recommends that operators focus more on Ethernet-based solutions, including Ethernet over fibre and Ethernet over copper, to optimise costs.

"In 2012, there will be a more distributed mix of backhaul technologies across the various options," said Manjaro.

"However, microwave is expected to be the primary backhaul solution in all the regions studied, except Latin America and North America.

"Ethernet over fibre will be a very popular choice for upgrades between now and 2012, primarily due to its lower cost per megabit and high data rate compared with other backhaul options."

As operators upgrade networks to meet growing bandwidth demand, they are upgrading to Ethernet-based solutions in both wired and wireless backhaul.

The location of cell sites in existing service provider infrastructure, bandwidth requirements, alternative carriers, interface requirements and other factors all play a role.