LR Live: Verizon Going All Ethernet for LTE

NEW YORK -- Backhaul & Core Strategies -- Verizon Wireless is in the midst of rolling out its 4G Long Term Evolution (LTE) network in the U.S. and is plotting an entirely Ethernet-based backhaul system to support the data onslaught.

Craig Frost, Verizon's executive director of network, told Light Reading Live attendees Tuesday that Ethernet over fiber is the carrier's preferred backhaul strategy wherever possible. Verizon had already begun migrating to fiber to its cell sites to deal with explosive 3G growth. On its CDMA network, Frost said fiber has improved reliability and scalability, as well as driven down cost per megabyte as the carrier grappled with increasing bandwidth demands. (See At Last: Ethernet Backhaul Booms for Carriers.)

"Even before the decision [to use Ethernet for LTE], we were wrestling with data demands that overwhelmed TDM [Time-division multiplexing]," Frost said.

Verizon is exploring both Ethernet over Sonet and native Ethernet, but in either case wants to migrate all its traffic from TDM to Ethernet in a 30-day period. That means no TDM for any purpose at all. Not voice nor data -- Verizon is moving it all.

And, so far, it hasn't dealt with Ethernet shortages in LTE. The number of providers has exceeded Verizon's expectations, Frost said.

"The marketplace has proven to be very strong," he said. Even so, Ethernet is far less standardized than TDM, Frost added, and vendors need to commit to certain service level agreements (SLAs) to make up for the variance.

Even though Ethernet over fiber is the clear winner for Verizon, Frost said that in some locations the economies of microwave are going to be the most beneficial. In these spots, primarily in rural America, Verizon is reviewing adaptive modulation techniques to extend its footprint, alongside picocells, distributed RAN architectures and other non-line-of-site wireless backhaul opportunities. (See LTE Backhaul? It's Complicated.)

Verizon currently has 73 markets and 60 airports covered with LTE and is planning to blanket 200 million people by the end of 2012. To help it achieve this goal, Frost called on the vendor community to commit to standards, compliance with SLAs and technical requirements, and clear processes for hitless bandwidth upgrades. (See Verizon Adds 19 New 4G LTE Markets.)

"As we continue to work through and measure the quality of our network, we're still looking for tools to measure what's going on in the network," Frost said. "We do need to be able to measure how it's performing, and we will need to continue this focus on reliability and optimization."

— Sarah Reedy, Senior Reporter, Light Reading Mobile