A fluid approximation gives the main term in the asymptotic expression of the value function for a controllable stochastic network. The policies which have the same asymptotic of their value functions as the value function of the optimal policy, are called asymptotically optimal policies. We consider a problem of finding from this set of asymptotically optimal policies a best one in the sense t...

Computer system models provide detailed answer to system performance. In this paper a two stage tandem network system with Blocking and Feedback is considered and it performance has been analyzed by spectral expansion method. The study state system with balance equations has been discussed.

We analyze the intermediate buffer requirements in a tandem queue where service times of each customer are deterministically correlated between the servers and arbitrarily distributed between customers. The major issue at hand is the determination of intermediate buffer sizes assuring no blocking when the arrivals pattern is arbitrary and unpredictable. The analysis shows that the worst arrival...

(1) In equation (8) on page 430, Cn+l should be replaced by Cn. (2) In lemma 3 on page 431, fqj= 1,3, 4, 5 should be replaced by t3j= 1,3,4, 5. (3) Theorem 2 on page 432 should be stated as: For two systems with a m _ 1 : k i n _ 1 andbm_ 1 = a m = 1, i fX <rh (resp. <~t)Ythen THBA < THBB. (4) Di(x,y) in lemma 6 should be replaced by Ii(x,y) on page 434. (5) Lemma 3 should be theorem 3 on page ...

We analyze the latency or sojourn time L(m,n) for the last customer in a batch of n customers to exit from the m-th queue in a tandem of m queues in the setting where the queues are in equilibrium before the batch of customers arrives at the first queue. We first characterize the distribution of L(m,n) exactly for every m and n, under the assumption that the queues have unlimited buffers and th...

We consider a retrial tandem queueing system with two servers whose service times follow two exponential distributions. There are two types of customers: type one and type two. Customers of type one arrive at the first server according to a Poisson process. An arriving customer of type one that finds the first server busy joins an orbit and retries to enter the server after some time. We assume...

We consider a model for to evaluate performance of streaming media over an unreliable network. Our model consists of a tandem of two fluid queues. The first fluid queue is a Markov Modulated fluid queue that models the network congestion, and the second queue represents the play-out buffer. For this model the distribution of the total amount of fluid in the congestion and play-out buffer corres...

We consider a two-stage tandem queue attended by a moving server, with homogeneous Poisson arrivals and general service times. Two different holding costs for stages 1 and 2 and different switching costs from one stage to the other are considered. We show that the optimal policy in the second stage is greedy; and if the holding cost rate in the second stage is greater or equal to the rate in th...

A systematic method for connection-wise endto-end delay analysis in asynchronous transfer mode (ATM) networks is proposed. This method consists of the followings: (i) per-stream nodal analysis; (ii) output processes characterization; and (iii) moment matching scheme. Following our previous work [1], we employ H-MMPPs/Slotted D/1 to model ATM queues. Each virtual connection (VC) in ATM networks ...

This paper represents linkage network of queues consisting of biserial and parallel servers linked to a common server in series with a flowshop scheduling system consisting of two machines. The significant transportation time of the jobs from one machine to another is also considered. Further, the completion time of jobs/customers (waiting time + service time) in the queue network is the set...