Title of article :
Statistical real-time communication over Ethernet
Author/Authors :
Kweon، Seok-Kyu نويسنده , , K.G.، Shin, نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2003
Pages :
-321
From page :
322
To page :
0
Abstract :
In order to realize real-time communication over Ethernet or fast Ethernet, one must be able to bound the medium access time within an acceptable limit. The multiple access nature of Ethernet makes it impossible to guarantee a deterministic medium access time (hence, packet-delivery deadlines) to individual stations. However, one can bound the medium access time statistically by limiting the packet-arrival rate at the medium access control (MAC) layer. While considering automated manufacturing systems as the main target application, this paper addresses the connection admission control (CAC) problem for statistically bounding the medium access time of Ethernet. Specifically, a packet is guaranteed to have a medium access time smaller than a predefined bound with a certain probability if the instantaneous packet-arrival rate is kept below a certain threshold. Through a mathematical analysis, we first derived such a threshold. In order to keep the packetarrival rate under the given threshold, we developed and installed middleware which 1) resides between the transport layer and the Ethernet datalink layer, and 2) smooths packet streams between them. The implementation of this middleware requires only a minimal change in the OS kernel without modification to the current standard of Ethernet MAC protocol or TCP or UDP/IP stack. In order to solve the CAC problem, we derived the probability of transmitting a packet successfully upon each trial by modeling the MAC protocol, 1persistent CSMA/CD, and the collision resolution protocol inary exponential backoff - of Ethernet. Our in-depth simulation results have shown this analytic model to provide a reasonably accurate estimate of packet-loss (or deadline-miss) ratio over fast Ethernet. Finally, we implemented the middleware on the Linux OS, experimentally demonstrating the effectiveness of our approach in providing real-time communication over Ethernet.
Keywords :
self-efficacy , motivational climate , perceived difficulty , goal involvement
Journal title :
IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS
Serial Year :
2003
Journal title :
IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS
Record number :
92234
Link To Document :
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