Verizon Wireless beefing up backhaul with carrier Ethernet

In preparation for the coming onslaught of 3G and 4G capacity demands, Verizon Wireless is making a major upgrade to its backhaul network that will see fiber pushed to thousands of new cell sites and the replacement of legacy transmission links with carrier Ethernet, allowing Verizon to more effectively scale capacity and better manage the expected data traffic spikes.

VZW is starting its capacity buildout with a close partner: its parent company. Verizon Partner Solutions, Verizon’s wholesale division, has agreed to supply fiber to 90% of the cell sites in its territory within the next 5 years--which roughly follows the timing of VZW’s long-term evolution (LTE) rollout plans--and upgrade all existing links to support carrier Ethernet. Verizon Wireless won’t be the only operator to benefit from the upgrades. Dozens of operators in Verizon’s territory can provision the links also. Verizon Wireless is one of the first to make a major move to carrier Ethernet, but it will be followed soon by its competitors, said Larry O’Neill, Manager of all Ethernet services for Verizon Partner Solutions.

“We’ve pitched these products to wireless carriers for two years,” O’Neill said. “They are now more prepared to move to Ethernet, and they’re prepared to move in mass.”

Business and technology considerations both contributed to the change in mindset, O’Neill said. The increased data traffic on 3G networks and expectations for far greater bandwidth demands on future long-term evolution (LTE) networks are the primary driver, he said, but only recently has the industry worked out some of the kinks that prevented carrier Ethernet from being an attractive backhaul technology. While optimal for data traffic, carrier Ethernet had to be augmented with more precise clocking, timing and synchronization techniques in order to support CDMA and GSM call quality and channel separation. Sometimes the obstacle is as simple as having an Ethernet port available, which only appears on newer base stations, O’Neill said.

By shifting from time division multiplexing (TDM) transport to Ethernet, Verizon will be able to carry both voice and data traffic over the same links. It will be able add capacity more flexibly, without relying on the hierarchy of the TDM. And it will be able to support different quality of service (QoS) tiers, meaning it can prioritize some traffic or applications over others when bottlenecks occur in the backhaul network.