DocumentCode :
1157679
Title :
Network classless time protocol based on clock offset optimization
Author :
Gurewitz, Omer ; Cidon, Israel ; Sidi, Moshe
Author_Institution :
Dept. of Electr. Eng., Israel Inst. of Technol., Haifa
Volume :
14
Issue :
4
fYear :
2006
Firstpage :
876
Lastpage :
888
Abstract :
Time synchronization is critical in distributed environments. A variety of network protocols, middleware and business applications rely on proper time synchronization across the computational infrastructure and depend on the clock accuracy. The Network Time Protocol (NTP) is the current widely accepted standard for synchronizing clocks over the Internet. NTP uses a hierarchical scheme in order to synchronize the clocks in the network. In this paper we present a novel non-hierarchical peer-to-peer approach for time synchronization termed CTP-Classless Time Protocol. This approach exploits convex optimization theory in order to evaluate the impact of each clock offset on the overall objective function. We define the clock offset problem as an optimization problem and derive its optimal solution. Based on the solution we develop a distributed protocol that can be implemented over a communication network, prove its convergence to the optimal clock offsets and show its properties. For compatibility, CTP may use the packet format and number of measurements used by NTP. We also present methodology and numerical results for evaluating and comparing the accuracy of time synchronization schemes. We show that the CTP outperforms hierarchical schemes such as NTP in the sense of clock accuracy with respect to a universal clock
Keywords :
Internet; clocks; middleware; peer-to-peer computing; protocols; synchronisation; Internet; clock accuracy; clock offset optimization problem; communication network; computational infrastructure; convex optimization theory; distributed protocol; network classless time protocol; nonhierarchical peer-to-peer approach; objective function; packet format; time synchronization; Ad hoc networks; Clocks; Computer networks; Delay estimation; Frequency synchronization; Global Positioning System; Protocols; Sensor phenomena and characterization; Sensor systems; Timing; Classless time protocol (CTP); UTC; estimation; measurements; network management; one-way delay; time synchronization;
fLanguage :
English
Journal_Title :
Networking, IEEE/ACM Transactions on
Publisher :
ieee
ISSN :
1063-6692
Type :
jour
DOI :
10.1109/TNET.2006.880181
Filename :
1677605
Link To Document :
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