Browsing by Author "Lin, MH"

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A dynamic incentive pricing scheme for relaying services in multi-hop cellular networks
(2004)
Lin, MH
;
Lo, CC
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Applying peer-to-peer communications in cellular networks to improve performance has been an active research area in recent years. Cooperation among nodes is an important prerequisite for the success of the multi-hop cellular networks. Cost savings and service availability are the primary concerns that the network provider adopts multi-hop cellular networking technology. In this paper, we present a dynamic incentive pricing scheme to maximize the revenue of the network provider. The proposed scheme adjusts the price of the feedback incentives based on the network conditions to influence the relaying capability of the network and therefore increases the revenue of the network provider. The simulation results demonstrate that the revenue can be increased by dynamically adjusting the price of the incentives for relaying services. Moreover, the proposed pricing scheme results in more revenue but does not cause higher new call blocking probability in multi-hop cellular networks.
A prepaid service-based charging and billing protocol for Internet services
(2002)
Lo, CC
;
Lin, MH
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
The explosive growth of Internet services makes ISPs necessitate a flexible and practical service-based charging model to promote various services in an increasingly competitive market. Much research has focused on transport-based charging that meters traffic volume or time duration as usage parameters. However, charging only for the transport negates the perceived value of the content and neglects the atomic nature of some services. In this paper, we present a prepaid service-based charging and billing protocol extended from the Remote Access Dial-In User Service (RADIUS) protocol because of its extensibility and deployments by a wide range of existing vendors. The proposed charging model classifies services into atomic service and divisible service. The atomic service is charged all or nothing based on the transmission status; the divisible service is charged in proportion to the service duration. This research also suggests charging Internet services by prepaid business model. The prepaid model attracts both the operators and the customers. The operators have the ability to monitor subscribers spending and prevent subscribers from using services they cannot afford real-time. The customers have the opportunity to control their own spending and take a limited amount of risk.
A quality of relay-based incentive pricing scheme for relaying services in multi-hop cellular networks
(2005)
Lin, MH
;
Lo, CC
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Cooperation among nodes is a critical prerequisite for the success of the relaying ad-hoe networks. Providing incentives for mobile nodes to forward data packets for others has received increasing attention. In this paper, we propose a Quality of Relay (QoR)-based pricing scheme to determine the price of the feedback incentives for intermediate nodes based on the individual importance of each mobile node contributing to successful hop-by-hop connections. Simulation results indicate that the QoR-based pricing scheme results in higher service availability than the fixed-rate pricing scheme under different relationships between price of feedback and willingness of forwarding packets. Moreover, the proposed pricing scheme shifts incentives from the nodes of low importance to the nodes of high importance in the networks so that it enhances service availability with only a slight increase in relaying costs.
Barrier capability of HfN films with various nitrogen concentrations against copper diffusion in CuHf-N/n(+)-p junction diodes
(2005)
Ou, KL
;
Chiou, SY
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Lin, MH
;
Hsu, RQ
;
機械工程學系
Hafnium-based (Hf-N) films were prepared by reactive radio frequency (rf)-magnetron sputtering on blank silicon wafers. Nitrogen incorporation and phase transformation of hafnium-based thin film were analyzed by cross-sectional transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The as-deposited Hf film has a hexagonal close-packed structure and a low resistivity of 48.29 muOmega cm. With increasing nitrogen concentration of Hf-N film, phase transformations are identified as alpha-Hf --> HfN0.4 --> epsilon-Hf3N2 --> fcc-HfN. The thermal stability of the Cu/Hf-N/Si contact system is evaluated by thermal stressing at various annealing temperatures. For the Cu/Hf/Si contact system, the inter-facial reaction between the Hf barrier layer and the Cu layer is observed after annealing at 550degreesC for 30 min, and copper-hafnium compounds form. Highly resistive copper silicide forms after annealing at 600degreesC for 30 min. The Elf barrier fails due to the reaction of Cu and the Hf barrier, in which Cu atoms penetrate into the Si substrate after annealing at high temperature. However, no copper-hafnium and copper silicide compounds are found for the Cu/HfN0.47/Si contact system even after annealing at 650degreesC for 30 min. A hafnium diffusion barrier incorporated with nitrogen can suppress the formation of copper-hafnium compounds and copper penetration, and thus enhance the thermal stability of the barrier layer. (C) 2005 The Electrochemical Society.
Comparative study of polycrystalline Ti, amorphous Ti, and multiamoIrphous Ti as a barrier film for Cu interconnect
(2005-01-01)
Ou, KL
;
Yu, MS
;
Hsu, RQ
;
Lin, MH
;
機械工程學系
Ultrathin (10 nm) Ti films with various structures were deposited by physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes. CVD-Ti films with low-temperature (<500degreesC) plasma-enhanced chemical vapor deposition Using TiCl4 and H-2 as reactants is an amorphous structure. This result is different from PVD-Ti films. deposited by magnetron sputtering, which have a columnar structure. Ammonia plasma was further employed to post-treat the CVD-Ti barrier layer to improve barrier properties. An amorphous Ti(N,H) layer was formed on the surface of the CVD-Ti layer after ammonia plasma post-treatment. The resultant films had a bilayered amorphous Ti(N,H)/Ti structure. Furthermore, the effective resistivity of the resultant Ti(N, H) /Ti film decreased to 122 muOmega cm. The thermal stability of Cu/PVD-Ti/Si and Cu/CVD-Ti/Si contact systems was evaluated by thermal stressing at various annealing temperatures. For the Cu/PVD-Ti/Si, the highly copper titanium compound was formed after 450degreesC annealing. The PVD Ti barrier failed initially due to the reaction of Cu and the Ti barrier, in which Cu atoms penetrated into the Si substrate after annealing at high temperature. However, no copper-titanium and copper-silicide compounds were found for amorphous Ti and plasma-treated Ti[Ti(N,H)/Ti] barriers, even after annealing at 500 and 600degreesC, respectively. Improved barrier capability against Cu diffusion was found for the Ti(N,H)/Ti barrier layer because the Cu/Ti(N,H)/Ti/n(+)-p junction diodes retained low leakage current densities even, after annealing at 500degreesC for 1 h., Ti(N,H)/Ti barrier layers present lengthened grain structures to effectively impede Cu diffusion, thus acting as much more effective barriers than conventional Ti and TiN films. (C) 2005 American Vacuum Society.
Copper interconnect electromigration behavior in various structures and precise bimodal fitting
(2006-02-01)
Lin, MH
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Lin, YL
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Chang, KP
;
Sul, KC
;
Wang, TH
Copper interconnect electromigration (EM) was examined in various structures and three low-k materials (k = 2.65-3.6) using advanced back-end-of-line (BEOL) technology. Various structures for testing were designed to identify the EM failure modes, and extensive failure analysis was carried out to reveal failure in the test structures. A strong current dependence of the electromigration lifetime in three-level via-terminated metal lines was shown. Moreover, different processing approaches lead to different EM behaviors and related failure modes. The weak links of the interconnect system were identified by evaluating various test structures. Multimodality in the electromigration behavior of Cu dual-damascene interconnects was studied. Both superposition and weak-link models were used for the statistical determination of lifetimes of each failure model (statistical method). Results correlated to the lifetimes of the respective failure models physically identified according to resistance time evolution behavior (physical method). A good agreement was achieved. The activation energies of failure modes were calculated. Results of this study suggest that the interface of Cu interconnects is the key factor in EM performance.
Electromigration lifetime improvement of copper interconnect by cap/dielectric interface treatment and geometrical design
(2005-12-01)
Lin, MH
;
Lin, YL
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Chen, JM
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Yeh, MS
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Chang, KP
A significant improvement of electromigration (EM) lifetime is achieved by modification of the preclean step before cap-layer deposition and by changing Cu cap/dielectric materials. A possible mechanism for EM lifetime enhancement was proposed. Cu-silicide formation prior to cap-layer deposition and adhesion of Cu/cap interface were found to be the critical factors in controlling Cu electromigration reliability. The adhesion of the Cu/cap interface can be directly correlated to electromigration median-time-to-failure and activation energy. Effects of layout geometrical variation and stress current direction were also investigated.
QoS provisioning in handoff algorithms for wireless LAN
(1998)
Lo, CC
;
Lin, MH
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
The performance of the handoff algorithm is the primary concern for supporting mobile devices with roaming capability in wireless communications. The IEEE 802.11 standard for wireless local area networks(LANs) recommends carrier sense multiple access with collision avoidance(CSMA/CA) as the medium access control(MAC) protocol. The contention-based CSMA/CA access mechanism is sensitive to the traffic load whereas the assignment-based access mechanism used by wireless telephone networks is not. Heavy traffic load in wireless LANs causes significant degradation of network performance. Thus conventional handoff algorithms employed in wireless telephone networks are not applicable to wireless LANs. In this paper, after examining existing handoff algorithms for wireless communications, we propose a handoff algorithm for wireless LANs. This algorithm considers traffic load as an important factor for initiating handoff. In normal traffic load, signal strength measurements from various access points are used the same as conventional handoff algorithms. However, in heavy traffic load, the hysteresis margin and the absolute threshold of traffic load are taken into account A simulation model is developed to study the performance of the proposed algorithm. Simulation results indicate that the proposed algorithm significantly reduces the call dropping probability. Moreover, the relationship between QoS parameters and handoff initiation criteria is analyzed. Analytical results show how handoff initiation criteria might be set in accordance with the quality of services requested by users.