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Evaluation of Novel Synchronization Algorithms for Circuit Emulation Adapters (2006)
BibTeX
@MISC{Und06evaluationof,
author = {Technische Informatik Und and Olga Bondareva and Ulrich Fiedler},
title = {Evaluation of Novel Synchronization Algorithms for Circuit Emulation Adapters},
year = {2006}
}
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Abstract
Packet switching technologies such as Gigabit Ethernet or IP over WDM are gradually replacing the traditional telephony (PDH/SDH) networks due to their ability to transport data traffic at very high rates. Connecting UMTS/GSM base stations over Metropolitan Gigabit Ethernets has a great potential of cost savings. In our scenario telephony base stations are connected to the core PDH network through a Metropolitan Gigabit Ethernet. This requires an emulation of E1/T1 telephone circuits over Gigabit Ethernets, i.e. E1/T1 PDH/SDH signals from base stations need to be packetized and encapsulated in a circuit emulation adapter (CEA) before being send over the Ethernet. After receiving the signals have to be reassembled. In contrast to VoIP, these emulated connections stay up for weeks. Thus, the on going frequency synchronization between the sender and the receiver clock is required. Much research has been conducted on the problem of clock synchronization. However, known algorithms such as the NTP and the Linear Regression do not meet stringent requirements of ITU-T G.823. In this report we present and evaluate open source implementations of synchronization algorithms: Convex Hull and Linear Adaptive Approximation. These algorithms are based on the concept of estimating the minimal end-to-end delay from sender and receiver time stamps. We show that such implementations meet the ITU-T G.823 requirements for synchronization and generally outperform the synchronization algorithms employed in commercially available circuit emulation adapters. 1
Keyphrases
circuit emulation adapter novel synchronization algorithm metropolitan gigabit ethernet gigabit ethernet stringent requirement high rate linear adaptive approximation available circuit emulation adapter evaluate open source implementation e1 t1 pdh sdh signal much research minimal end-to-end delay core pdh network umts gsm base station clock synchronization pdh sdh base station convex hull receiver time stamp frequency synchronization cost saving synchronization algorithm great potential linear regression traditional telephony data traffic scenario telephony base station e1 t1 telephone circuit receiver clock
