Browsing by Author "Lin, LF"

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A QoS-provisioning neural fuzzy connection admission controller for multimedia high-speed networks
(1999-02-01)
Cheng, RG
;
Chang, CJ
;
Lin, LF
;
電信工程研究所
;
電信研究中心
This paper proposes a neural fuzzy approach for connection admission control (CAC) with QoS guarantee in multimedia high-speed networks. Fuzzy logic systems have been successfully applied to deal with traffic-control-related problems and have provided a robust mathematical framework for dealing with real-world imprecision. However, there is no clear and general technique to map domain knowledge on traffic control onto the parameters of a fuzzy logic system. Neural networks have learning and adaptive capabilities that can be used to construct intelligent computational algorithms for traffic control. However, the knowledge embodied in conventional methods is difficult to incorporate into the design of neural networks. The proposed neural fuzzy connection admission control (NFCAC) scheme is an integrated method that combines the linguistic control capabilities of a fuzzy logic controller and the learning abilities of a neural network. It is an intelligent implementation so that it can provide a robust framework to mimic experts' knowledge embodied in existing traffic control techniques and can construct efficient computational algorithms for traffic control. We properly choose input variables and design the rule structure for the NFCAC controller so that it can have robust operation even under dynamic environments. Simulation results show that compared with a conventional effective-bandwidth-based CAC, a fuzzy-logic-based CAC, and a neural-net-based CAC, the proposed NFCAC can achieve superior system utilization, high learning speed, and simple design procedure, while keeping the QoS contract.
An enhanced traffic marker for DiffServ networks
(2005)
Lin, LF
;
Yan, NY
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Chang, CJ
;
Cheng, RG
;
電信工程研究所
In this paper, we propose an enhanced traffic marker (ETM) to amend the inappropriate marking in DiffServ networks. The ETM is based on the Two-Rate-Three-Color-Marker (TRTCM) scheme and introduces the feature of aggressive promotion and fair share marking. Simulation results show that the ETM fairly allocates bandwidth among micro-flows and achieves a higher throughput than TRTCM does.
Intelligent leaky bucket algorithms for sustainable-cell-rate usage parameter control in ATM networks
(2004-10-01)
Chang, CJ
;
Yu, CH
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Chang, CS
;
Lin, LF
;
電信工程研究所
In this paper, we propose two intelligent leaky bucket algorithms for sustainable-cell-rate usage parameter control of multimedia transmission in asynchronous transfer mode networks. One is the fuzzy leaky bucket algorithm, in which a fuzzy increment controller (FIC) is incorporated with the conventional leaky bucket algorithm; the other is the neural fuzzy leaky bucket algorithm, where a neural fuzzy increment controller (NFIC) is added with the conventional leaky bucket algorithm. Both the FIC and the NFIC properly choose the long-term mean cell rate and the short-term mean cell rate as input variables to intelligently determine the increment value. Simulation results show that both intelligent leaky bucket algorithms have significantly outperformed the conventional leaky bucket algorithm, by responding about 160% faster when taking control actions against a nonconforming connection while reducing as much as 50% of the queueing delay experienced by a conforming connection. In addition, the neural fuzzy leaky bucket algorithm outperforms the fuzzy leaky bucket algorithm, in aspects of three performance measures such as selectivity, responsiveness, and queueing delay, especially when the traffic flow is bursty, dynamic, and nonstationary.
Intelligent leaky bucket algorithms for sustainable-cell-rate usage parameter control in ATM networks
(2001)
Chang, CJ
;
Chang, CS
;
Eul, Z
;
Lin, LF
;
電信工程研究所
In this paper, we propose two intelligent leaky bucket algorithms for sustainable-cell-rate usage parameter control in ATM networks. One is the fuzzy leaky bucket algorithm, where a fuzzy increment controller is incorporated with the conventional leaky bucket algorithm; the other is the neural fuzzy leaky bucket algorithm, where a neural fuzzy increment controller is added with the conventional leaky bucket algorithm. The fuzzy and neural fuzzy increment controllers properly choose the long-term mean cell rate and the short-term mean cell rate as input variables and intelligently compute to determine the increment value. Three performance measures such as selectivity, responsiveness, and queueing delay are investigated. The intelligent fuzzy leaky bucket algorithms cart have performance better than the conventional leaky bucket algorithm. And the neural fuzzy leaky bucket algorithm outperforms the fuzzy leary bucket algorithm.
Power-spectrum-based neural-net connection admission control for multimedia networks
(2002-04-01)
Chang, CJ
;
Lin, LF
;
Lin, SY
;
Cheng, RG
;
電信工程研究所
Multimedia networks need sophisticated and real-time connection admission control (CAC) not only to guarantee the required quality of service (QoS) for existing calls but also to enhance utilisation of systems. The power spectral density (PSD) of the input process contains correlation and burstiness characteristics of input traffic and possesses the additive property. Neural networks have been widely employed to deal with the traffic control problems in high-speed networks because of their self-learning capability. The authors propose a power-spectrum-based neural-net connection admission control (PNCAC) for multimedia networks. A decision hyperplane is constructed for the CAC using power spectrum parameters of traffic sources of connections, tinder the constraint of the QoS requirement. Simulation results show that the PNCAC method provides system utilisation and robustness superior to the conventional equivalent capacity CAC scheme and Hiramatsu's neural network CAC scheme, while meeting the QoS requirement.
The traffic conditioner with promotion and fairness guarantee schemes for DiffServ networks
(2003)
Chang, CJ
;
Cheng, YH
;
Lin, LF
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, we propose a traffic conditioner with promotion and fairness guarantee (TC_PFG) schemes to amend the inappropriate marking by conventional traffic conditioners. The TC_PFG is based on the Two Rate Three Color Marker (TRTCM) scheme. It can allocate appropriate bandwidth to micro-flows to reduce the unfair distribution among micro-flows and improve the utilization by allowing promotion of packets when there is available bandwidth. Simulation results show that TC_PFG outperforms TRTCM; the former achieve higher fairness among micro-flows and better throughput than the latter.