4G backhaul--an opportunity and a dilemma

There are no easy answers to the hard questions bandwidth-intensive 3G and 4G backhaul pose for wireless carriers. There are, however, enough possibilities--from packetized bonded copper to cable-proffered fiber links--that mobile carriers should be able to determine an economically and structurally efficient way to move ahead before data traffic congestion causes gridlock.

"There are no absolute statements you could can make about mobile backhaul because every operator has built the network differently, had a different migration strategy, different requirements," said Taylor Salman, director of solutions market for Ciena. "There's no consistency across it."

Keeping costs in check

There may not be network consistency, but there is a common message: Backhaul must be upgraded even though this is a lousy time to spend money.

"If you want to offer a fairly high-bandwidth pipe and you want to be able to make some money on it, the only way to do that and be cost-effective is to have a very efficient infrastructure," said Glenn Hunt, principal analyst at Current Analysis.

"All the newer systems are all-IP, so there are no circuit-switched voice or SMS applications," said Salman. "That being said, there's a lot invested in the current infrastructure, which is TDM-based, and they'll use that equipment until it falls apart."

Legacy backhaul has generally consisted of leased TDM T1 lines that work fine for low bandwidth voice traffic but are too narrow to handle wideband video and other Internet-type applications now running over cell networks.

"It needs to be packets," said Steve Dyck, director of mobile backhaul solutions for Alcatel-Lucent. "The mobile operator has to be able to manage growth on the network while staying on a TDM-based infrastructure. Packet can be over fiber, it can be over copper for some short distances, and it can be over microwave."

Pseudowire, which blends legacy TDM while moving to a cellular Ethernet architecture, also has potential...Continue

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