The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
D Sandhu - One of the best experts on this subject based on the ideXlab platform.
-
Delay analyses of token-passing protocols with limited token holding times
IEEE Transactions on Communications, 1994Co-Authors: K.c. Chang, D SandhuAbstract:The primary concern of this paper is delay analysis of IEEE 802.4 token-bus, IEEE 802.5 token-ring, and Fiber Distributed Data Interface (FDDI) when all the network traffic is of the highest priority class. We model them in an unified manner as a Cyclic-Service system with exhaustive time-limited Service policies. We have specifically pointed out two variants of the time-limited Service policies-nonpreemptive and look-ahead. The former models the token-bus, and the latter models the token-ring and FDDI. The major result of this paper is an iterative algorithm to approximate the mean delays for the nonpreemptive policy. Numerical results show that the algorithm is reasonably accurate for both deterministic and exponential frame sizes. Last, we apply the algorithm to the performance analysis of a token-bus. In the appendix, we also outline a similar approach for the look-ahead policy. >
-
INFOCOM - Delay analyses of token-passing protocols with limited token holding times
[Proceedings] IEEE INFOCOM '92: The Conference on Computer Communications, 1992Co-Authors: K.c. Chang, D SandhuAbstract:The authors consider the IEEE 802.4 token-bus, IEEE 802.5 token-ring, and Fiber Distributed Data Interface (FDDI) network standards. They perform the delay analyses for these token-passing network standards when all the network traffic is of the highest priority class. They model them in an unified manner as a Cyclic-Service system with exhaustive time-limited Service policies. They have specifically considered two variants of the time-limited Service policies-nonpreemptive and look-ahead. The former models the token-bus and the latter models the token-ring and FDDI. The major result is an algorithm to approximate the mean delays for the nonpreemptive policy. Numerical results show that the algorithm is reasonably accurate for deterministic and exponential frame sizes. The algorithm is applied to the performance analysis of a token-bus. A similar approach for the look-ahead policy is outlined. >
-
INFOCOM - Delay analyses of token-passing protocols with limited token holding times
[Proceedings] IEEE INFOCOM '92: The Conference on Computer Communications, 1992Co-Authors: K.c. Chang, D SandhuAbstract:The authors consider the IEEE 802.4 token-bus, IEEE 802.5 token-ring, and Fiber Distributed Data Interface (FDDI) network standards. They perform the delay analyses for these token-passing network standards when all the network traffic is of the highest priority class. They model them in an unified manner as a Cyclic-Service system with exhaustive time-limited Service policies. They have specifically considered two variants of the time-limited Service policies-nonpreemptive and look-ahead. The former models the token-bus and the latter models the token-ring and FDDI. The major result is an algorithm to approximate the mean delays for the nonpreemptive policy. Numerical results show that the algorithm is reasonably accurate for deterministic and exponential frame sizes. The algorithm is applied to the performance analysis of a token-bus. A similar approach for the look-ahead policy is outlined. >
-
Mean waiting time approximations in Cyclic-Service systems with exhaustive limited Service policy
Performance Evaluation, 1992Co-Authors: Kow C. Chang, D SandhuAbstract:Abstract In this paper, we consider a Cyclic-Service system with exhaustive limited Service policy (or k -limited). Under this policy, the server may serve up to a maximum of k customers during his visit at the queue. The major result here is a new approximation procedure to compute the individual mean waiting times. This approximation is based on the pseudo-conservation law and on the concept of conditional cycle times. Extensive numerical examples show that this new approximation is more accurate and robust than the two other heuristic models reported in the literature. Furthermore, its accuracy improves significantly as the number of queues increases and its performance does not seem to be affected by k . The overall performance characteristic, thus, allows this approximation to model token-passing network protocols.
-
mean waiting time approximations in Cyclic Service systems with exhaustive limited Service policy
International Conference on Computer Communications, 1991Co-Authors: Kow C. Chang, D SandhuAbstract:Motivated by token-passing protocols in LANs, a system of multiple queues, attended by a Cyclic server, is considered. The server will switch from the i/sup th/ queue to the next when either K/sub i/ customers are served consecutively or the queue is empty, whichever comes first. Using the pseudoconservation laws, an approximation method is developed to obtain the mean waiting time for each queue. The performance of this approximation is shown to be more robust and accurate then previous heuristic approximations. Further, it is shown to be suitable for modeling token-passing LANs. >
Kin K. Leung - One of the best experts on this subject based on the ideXlab platform.
-
Cyclic-Service systems with nonpreemptive, time-limited Service
IEEE Transactions on Communications, 1994Co-Authors: Kin K. LeungAbstract:We analyze an asymmetric Cyclic-Service system with multiple queues and nonpreemptive, time-limited Service. The time limit for a server visit at each queue is exponentially distributed. Customer Service times and changeover times have general distributions. Using discrete Fourier transforms, the queue-length and delay distributions are solved. >
-
Cyclic-Service systems with probabilistically-limited Service
IEEE Journal on Selected Areas in Communications, 1991Co-Authors: Kin K. LeungAbstract:An asymmetric Cyclic-Service system with a probabilistically limited (PL) Service policy is analyzed. In such a Service policy, the maximum number of customers served at a queue during a server visit is determined by a probability which is independent of system states. Exhaustive, limited-k, and Bernoulli Services are special cases of the PL policy. Customer Service times and changeover times have general distribution. A numerical technique based on discrete Fourier transforms is proposed to solve for the queue-length distributions. Thus, the waiting and response-time distribution are obtained. A set of numerical examples is presented to validate the approach. >
K.c. Chang - One of the best experts on this subject based on the ideXlab platform.
-
Delay analyses of token-passing protocols with limited token holding times
IEEE Transactions on Communications, 1994Co-Authors: K.c. Chang, D SandhuAbstract:The primary concern of this paper is delay analysis of IEEE 802.4 token-bus, IEEE 802.5 token-ring, and Fiber Distributed Data Interface (FDDI) when all the network traffic is of the highest priority class. We model them in an unified manner as a Cyclic-Service system with exhaustive time-limited Service policies. We have specifically pointed out two variants of the time-limited Service policies-nonpreemptive and look-ahead. The former models the token-bus, and the latter models the token-ring and FDDI. The major result of this paper is an iterative algorithm to approximate the mean delays for the nonpreemptive policy. Numerical results show that the algorithm is reasonably accurate for both deterministic and exponential frame sizes. Last, we apply the algorithm to the performance analysis of a token-bus. In the appendix, we also outline a similar approach for the look-ahead policy. >
-
INFOCOM - Delay analyses of token-passing protocols with limited token holding times
[Proceedings] IEEE INFOCOM '92: The Conference on Computer Communications, 1992Co-Authors: K.c. Chang, D SandhuAbstract:The authors consider the IEEE 802.4 token-bus, IEEE 802.5 token-ring, and Fiber Distributed Data Interface (FDDI) network standards. They perform the delay analyses for these token-passing network standards when all the network traffic is of the highest priority class. They model them in an unified manner as a Cyclic-Service system with exhaustive time-limited Service policies. They have specifically considered two variants of the time-limited Service policies-nonpreemptive and look-ahead. The former models the token-bus and the latter models the token-ring and FDDI. The major result is an algorithm to approximate the mean delays for the nonpreemptive policy. Numerical results show that the algorithm is reasonably accurate for deterministic and exponential frame sizes. The algorithm is applied to the performance analysis of a token-bus. A similar approach for the look-ahead policy is outlined. >
-
INFOCOM - Delay analyses of token-passing protocols with limited token holding times
[Proceedings] IEEE INFOCOM '92: The Conference on Computer Communications, 1992Co-Authors: K.c. Chang, D SandhuAbstract:The authors consider the IEEE 802.4 token-bus, IEEE 802.5 token-ring, and Fiber Distributed Data Interface (FDDI) network standards. They perform the delay analyses for these token-passing network standards when all the network traffic is of the highest priority class. They model them in an unified manner as a Cyclic-Service system with exhaustive time-limited Service policies. They have specifically considered two variants of the time-limited Service policies-nonpreemptive and look-ahead. The former models the token-bus and the latter models the token-ring and FDDI. The major result is an algorithm to approximate the mean delays for the nonpreemptive policy. Numerical results show that the algorithm is reasonably accurate for deterministic and exponential frame sizes. The algorithm is applied to the performance analysis of a token-bus. A similar approach for the look-ahead policy is outlined. >
Toshiharu Hasegawa - One of the best experts on this subject based on the ideXlab platform.
-
A Cyclic-Service finite source model with round-robin scheduling
Queueing Systems, 1992Co-Authors: Tetsuya Takine, Toshiharu HasegawaAbstract:A Cyclic-Service finite source model with round-robin scheduling is considered. A single server scans sources in a Cyclic manner whether there is a request or not. Each request consists of multiple tasks and only one task can be served when the server scans. We provide the exact analysis of the average response time in a heterogeneous finite source model, where the Service times of tasks are distributed according to general probability distributions which may be different from one source to another. Further, we derive the Laplace-Stieltjes transform of the probability distribution function of the waiting time.
-
Sojourn times in vacation and polling systems with Bernoulli feedback
Journal of Applied Probability, 1991Co-Authors: Tetsuya Takine, H. Takagi, Toshiharu HasegawaAbstract:We study sojourn times in M/G/1 multiple vacation systems and multiqueue Cyclic-Service (polling) systems with instantaneous Bernoulli feedback. Three Service disciplines, exhaustive, gated, and 1-limited, are considered for both M/G/1 vacation and polling systems. The Laplace-Stieltjes transforms of the sojourn time distributions in the three vacation systems are derived. For polling systems, we provide explicit expressions for the mean sojourn times in symmetric cases. Furthermore a pseudo-conservation law with respect to the mean sojourn times is derived for a polling system with a mixture of the three Service disciplines.
Kow C. Chang - One of the best experts on this subject based on the ideXlab platform.
-
Stability conditions for a pipeline polling scheme in satellite communications
Queueing Systems, 1993Co-Authors: Kow C. ChangAbstract:This paper considers the unknown stability conditions of a pipeline polling scheme proposed for satellite communications. This scheme is modelled as a Cyclic-Service system with limited Service and reservation. The walk times and the maximum number of Services to be performed during each polling are dependent on the queue lengths of the stations. The main result is the derivation of the necessary and sufficient stability conditions of the system. Our approach is to map the multi-dimensional stability problem into many 1-dimensional stability problems through the concept of the least stable queue. The least stable queue is one that will become unstable first when the system load increases in some parameter region. The stability of the least stable queue thus implies stability of the system. The stability region for the whole system is then the union of the queue stability regions of all the least stable queues that are obtained through dominant systems and Loynes' theorem. We also propose a computable sufficient condition that is tighter than the existing result and present some numerical results.
-
Pseudo-conservation laws in Cyclic-Service systems with a class of limited Service policies
Annals of Operations Research, 1992Co-Authors: Kow C. Chang, Deniz SandhuAbstract:This paper considers a Cyclic-Service system with a class of limited Service policies that consists of exhaustive limited, gated limited and general decrementing policies. Under these policies, the number of customers served consecutively during a server visit is limited by a vector of integers. The major results in this paper are derivations of expected amount of work left in the queues at the server departures for these three policies. Exact expressions of weighted sum of mean waiting times, known as pseudo-conservation laws, are subsequently obtained. The conservation laws for this class of policies contain unknown boundary probabilities. We estimate these probabilities using corresponding server vacation models. Numerical results presented for the exhaustive limited policy are noted to be very accurate compared with simulation results. Moreover, we have obtained analytical bounds for the weighted sums. Finally, we present a conservation law with mixed Service policies, and mean waiting times for symmetric systems.
-
Mean waiting time approximations in Cyclic-Service systems with exhaustive limited Service policy
Performance Evaluation, 1992Co-Authors: Kow C. Chang, D SandhuAbstract:Abstract In this paper, we consider a Cyclic-Service system with exhaustive limited Service policy (or k -limited). Under this policy, the server may serve up to a maximum of k customers during his visit at the queue. The major result here is a new approximation procedure to compute the individual mean waiting times. This approximation is based on the pseudo-conservation law and on the concept of conditional cycle times. Extensive numerical examples show that this new approximation is more accurate and robust than the two other heuristic models reported in the literature. Furthermore, its accuracy improves significantly as the number of queues increases and its performance does not seem to be affected by k . The overall performance characteristic, thus, allows this approximation to model token-passing network protocols.
-
mean waiting time approximations in Cyclic Service systems with exhaustive limited Service policy
International Conference on Computer Communications, 1991Co-Authors: Kow C. Chang, D SandhuAbstract:Motivated by token-passing protocols in LANs, a system of multiple queues, attended by a Cyclic server, is considered. The server will switch from the i/sup th/ queue to the next when either K/sub i/ customers are served consecutively or the queue is empty, whichever comes first. Using the pseudoconservation laws, an approximation method is developed to obtain the mean waiting time for each queue. The performance of this approximation is shown to be more robust and accurate then previous heuristic approximations. Further, it is shown to be suitable for modeling token-passing LANs. >
-
INFOCOM - Mean waiting time approximations in Cyclic-Service systems with exhaustive limited Service policy
IEEE INFCOM '91. The conference on Computer Communications. Tenth Annual Joint Comference of the IEEE Computer and Communications Societies Proceeding, 1991Co-Authors: Kow C. Chang, D SandhuAbstract:Motivated by token-passing protocols in LANs, a system of multiple queues, attended by a Cyclic server, is considered. The server will switch from the i/sup th/ queue to the next when either K/sub i/ customers are served consecutively or the queue is empty, whichever comes first. Using the pseudoconservation laws, an approximation method is developed to obtain the mean waiting time for each queue. The performance of this approximation is shown to be more robust and accurate then previous heuristic approximations. Further, it is shown to be suitable for modeling token-passing LANs. >
