EA Peer Reviewed: Delivery of Timing and Circuit Services using Packet-based Synchronization
Delivery of Timing and Circuit Services using Packet-based Synchronization
Written by Nir Halachmi
Abstract
As mobile operators migrate to 4G and LTE networks to support the ever increasing bandwidth demands of smartphones and tablets, they are faced with the challenge of supporting legacy 2G and 3G technologies. This migration to packet-based mobile backhaul across 2G and 3G cell sites needs to address the diverse synchronization requirements needed to ensure delivery of both packet-based and circuit services. This paper provides examples of specific synchronization deployments for 2G, 3G and 4G mobile backhaul architectures using appropriate timing mechanisms to support converged voice, video, data and mobile services over Ethernet.
This paper assumes some understanding of the various technologies discussed, i.e. Synchronous Ethernet (SyncE), IEEE-1588-2008 Precision Time Protocol (PTPv2) and Circuit Emulation. E1s and SDH STM circuits are illustrated in the figures, but all discussions are relevant to North American T1 and SONET deployments as well.
Introduction
As broadband Ethernet services are becoming a commodity, mobile network providers, business owners and service providers are examining ways to take advantage of these services for delivery of their packet based communications and legacy circuit services.
Mobile operators in particular are upgrading their mobile backhaul networks to support the rapidly growing mobile data traffic volume, and are turning to Ethernet to gain substantial network efficiency and minimize operational and capital expenses. To maximize the return on investment, the Ethernet backhaul is required to converge voice, video, data and mobile services and provide tight frequency and phase synchronization to cell sites using Sync-E, IEEE-1588 v2 and/or GPS technologies.
This paper addresses the deployment of mobile backhaul as well as Ethernet and Legacy services to business and residential customers and the important role that the emerging use of packet-based synchronization methods play in the delivery of these services.
Specifically, the paper discusses:
- The appropriate combinations of clock recovery methods for the delivery of circuit and timing services for co-located 2G, 3G and 4G deployments, including the combination of Synchronous Ethernet and IEEE-1588 Precision Time Protocol network synchronization methods with Circuit Emulation’s Adaptive and Differential clock recovery methods.
- A synchronized metro-access network that offers Ethernet, timing and circuit services to customers.
- The implication of the availability of synchronous clock at the edge of the network on the deployment of mobile backhaul and business connectivity services over such packet switched networks.
- Emerging transparent timing services and its potential implication on the backhaul network.
