基于公平期的循环服务——一种用于ATM网络的简单公平信元调度机制

Fair-cycle-based round robin service——a simple and fair cell scheduling scheme for ATM networks

为了在ATM网络中简洁及公平地实现信元调度 ,本文提出了一种新的公平服务规则 :基于公平期的循环服务 (简称为FCRR) ,FCRR将理想的公平服务准则与经典循环服务的简单性有机地相结合 ,以接近于经典循环服务的代价实现了在每个“公平期”上对各用户业务的公平服务。在给出了“公平基”和“公平期”的概念后 ,我们证明了FCRR在每个“公平期”上服务的公平性 ,导出了FCRR的最差公平性和信元时延上界 ,与转交式循环服务 (CORR)相比 ,FCRR具有更好的公平服务特性。相应的模拟分析进一步表明 ,FCRR的公平性明显优于CORR ,并对高速业务具有比CORR更好的时延特性。

In order to schedule cells fairly and cost effectively in ATM networks,this paper develops a new type of fair service scheme called the “fair cycle based”round robin service(FCRR for short below) FCRR combines efficiently the fairness of an ideal fair service with the simplicity of a typical“round robin”service so that it can provide real fair service over each“fair allocation cycle”to all connections at low cost very close to that of a simple round robin Also,we analyze the worse case fairness(i e the maximum unfairness),the upper cell delay bound,and the computation complexity of an FCRR server The analysis presented in this paper shows that FCRR compares favorably with the“carry over round robin”(CORR for short)in terms of both fairness and computation complexity The numerical results obtained from a simulation study further support the theoretical analysis,with two main conclusions that FCRR is evidently superior to CORR in terms of fairness and can offer higher rate connections much better delay properties