Alcatel-Lucent taps Symmetricom for Ethernet synch

As mobile operators look to Ethernet as a solution to meet their exploding data requirements, they open up new needs for technology to synch up voice traffic over their increasingly data-focused mobile backhaul networks.

Today, Alcatel-Lucent said it will resell Ethernet synch solutions from vendor Symmetricom, in particular its implementations of IEEE 1588 Precision Time Protocol (PTP) synchronization technology. The move of 1588-based synch solutions into the telecom arena is relatively new, as is the reliance by service providers on their vendors to vet and provide voice timing technology. Synchronization of base stations is a critical component in ensuring quality of service in Ethernet-based networks.

In traditional voice networks, synch and timing was provided at the transport layers as part of Sonet/SDH-based networks. That’s changing in tomorrow’s more data-centric 4G mobile networks. In many cases, mobile operators will move only their data traffic onto Ethernet-based backhaul links, retaining T-1s/E-1s to carry voice. But the ultimate goal is to converge both voice and data onto Ethernet, said Eric Colard, director of business development-telcom solutions for Symmetricom.

“Ethernet breaks the synchronization chain,” Colard said. “[Operators] have to find another way to define synchronization” in the backhaul network.

Several factors determine the synching requirements, Colard said, starting with the base station approach: a femtocell approach allows for more relaxed synchronization; micro base stations have more strict requirements. Meanwhile, some radio technologies require just frequency synchronization; others like LTE-TDD also require time and phase synchronization, he said.

One solution for operators and backhaul providers is to deploy synchronous Ethernet technology. However, that requires upgrading every switch and router on the network, which can be expensive (or impossible if the operator is leasing backhaul capacity from another provider).

IEEE 1588-based synch represents another alternative, a synch/timing protocol that began in the industry automation sector but in its second version was adopted for telecom, including Ethernet synchronization.

Symmetricom has implemented its 1588 solution in a variety of flavors, including as a blade running on its core synch products – the SSU 2000 and TimeHub – as well as a stand-alone product, the TimeProvider 5000 IEEE 1588 Grandmaster Clock. In addition to those implementations, Symmetricom also offers  software version of its 1588 solution, which lets other vendors embed the protocol in their own platforms, Colard said.

Alcatel-Lucent has been working with Symmetricom on timing issues for some time, Colard said. The most recent move involves the network equipment provider reselling Symmetricom 1588 solutions in order to provide its mobile operators with complete end-to-end 4G/Ethernet solutions, he said.

Symmetricom has a similar relationship with Nokia Siemens Networks to provide that vendor with Ethernet timing solutions.

While in the past Symmetricom would often sell timing solutions directly to service providers, that’s changing, as network equipment providers increasingly serve as systems integrators for telco network deployments, Colard said.

“Telecom operators used to have synch experts that were dedicated to evaluating and buying synch technologies; today those people are retiring or close to retiring,” Colard said. “The trend today is that carriers outsource that evaluation to network equipment providers.”