Changes In Network Resources Research Articles

A new quantum key distribution resource allocation and routing optimization scheme

Quantum key distribution (QKD) is a technology that can resist the threat of quantum computers to existing conventional cryptographic protocols. However, due to the stringent requirements of the quantum key generation environment, the generated quantum keys are considered valuable, and the slow key generation rate conflicts with the high-speed data transmission in traditional optical networks. In this paper, for the QKD network with a trusted relay, which is mainly based on point-to-point quantum keys and has complex changes in network resources, we aim to allocate resources reasonably for data packet distribution. Firstly, we formulate a linear programming constraint model for the key resource allocation (KRA) problem based on the time-slot scheduling. Secondly, we propose a new scheduling scheme based on the graded key security requirements (GKSR) and a new micro-log key storage algorithm for effective storage and management of key resources. Finally, we propose a key resource consumption (KRC) routing optimization algorithm to properly allocate time slots, routes, and key resources. Simulation results show that the proposed scheme significantly improves the key distribution success rate and key resource utilization rate, among others.

Q-DDCA: Decentralized Dynamic Congestion Avoid Routing in Large-Scale Quantum Networks

The quantum network that allows users to communicate in a quantum way will be available in the foreseeable future. The network capable of distributing Bell state entangled pairs faces many challenges due to entanglement decoherence and limited network performance, especially when the network scale is enormous. Many entanglement distribution protocols have been proposed so far, and most of them are in a centralized and synchronized manner, which may be infeasible in large-scale networks. As such, in this paper, we propose a full spontaneous version of quantum networks in which the quantum nodes autonomously manage multiple entanglement distribution requests. However, one major issue is that quantum nodes have little knowledge about the network, especially the congestion (e.g., some nodes may have no usable quantum memories). We present a routing algorithm to adaptive evaluate the congestion on the neighbor nodes to avoid potential congestion. We use SimQN, the new network layer simulation platform built by our research team, to evaluate our proposed design. The result demonstrates that it can adapt to changes in network resources and reduce the drop rate that eventually leads to a higher entanglement distribution rate but remains fair for multiple requests to use the network resources fairly and achieve a more balanced throughput.

Resource Criticality Analysis of Static Resource Allocations and Its Applications in WDM Network Planning

Various static resource allocation algorithms have been used in WDM networks to allocate resources such as wavelength channels, transmitters, receivers, and wavelength converters to a given set of static lightpath demands. However, although optimized resource allocations can be obtained, it remains an open issue how to determine which resources are the bottlenecks in achieving better performance. Existing static resource allocation algorithms do not explicitly measure the impact of changes of network resources or lightpath demands on the design objective. We propose such a measurement based on the Lagrangian relaxation framework. We use the optimized values of Lagrange multipliers as a direct measurement of the criticality of resources. Such a quantitative measurement can be naturally acquired along with the optimization process to obtain the optimal solution (or a near-optimal solution) to the static routing and wavelength assignment problem. We investigate three practical applications of the resource criticality (RC) analysis in WDM network planning. In the first application, we use our proposed measurement to identify critical resources and thus to decide the best way to add or reallocate resources. In the second application, we estimate the impact of the addition or removal of lightpath demands on the design objective. This kind of estimation helps to set a proper price for lightpath demands. In the third application, the results of the RC analysis are used to speed up the convergence of the optimization process for different network scenarios.

A New QoS Routing Scheme Based on Bandwidth Consumption for MANETs

Quality of Service (QoS) routing in Mobile Ad hoc NETworks (MANETs) is hard to achieve because the network topology tends to change constantly in a dynamic network. In this paper, we propose an effective QoS routing scheme to satisfy the required service demand and adapt to the dynamic changes in network resources. This novel approach of Application-Level QoS Routing Scheme (ALRS) comprises three significant features: (1) Estimation of consumed bandwidth on each node by using 2-hop neighbors' traffic information, (2) Route construction combined with admission control on each application session with (1), and (3) Route maintenance based on (1) and (2). By using our proposed ALRS scheme the availability of bandwidth is greatly improved for high-load communications, such as multimedia applications. By computer simulation we confirmed that ALRS increases the delivery ratio by up to 50% and decreases delay by less than one-fourth of the existing traditional method.

MBMS Handover control: A new approach for efficient handover in MBMS enabled 3G cellular networks

With the introduction of Multimedia Broadcast Multicast Service (MBMS) system in 3rd Generation (3G) mobile cellular networks , the Radio Network Controller (RNC) for radio resource efficiency can use either Point-to-Point (one Dedicated Channel per User Equipment (UE) in the Cell) or Point-to-Multipoint (one Common Channel shared by all the UEs in the Cell) transmission mode, to distribute the same MBMS content in a Cell. Thus, the mobile users that are on the move and receive an MBMS service may have to deal with dynamic changes of network resources when crossing the Cell’s edge, introducing new types of handovers ( MBMS Handovers ); from Point-to-Point to Point-to-Multipoint transmission mode Cell and vice versa. Executing an MBMS Handover using the existing handover control approach, as described in 3GPP TR 25.922 specifications, results in inefficiencies due to the approach used. In this paper, we highlight these inefficiencies and propose and evaluate a new handover control approach to address them. As illustrated in our performance evaluation, compared to the existing approach, the proposed approach improves the overall system capacity and link performance and avoids any QoS degradation (seamless handover) during an MBMS Handover.

Adaptive network QoS in layer-3/layer-2 networks as a middleware service for mission-critical applications

We present adaptive network Quality of Service (QoS) technology that provides delay bounds and capacity guarantees for traffic belonging to mission-critical tasks. Our technology uses a Bandwidth Broker to provide admission control and leverages the differentiated aggregated traffic treatment provided by today’s high-end COTS layer-3/2 switches. The technology adapts to changes in network resources, work load and mission requirements, using two components that are a particular focus of this paper: Fault Monitor and Performance Monitor. Our technology is being developed and applied in a CORBA-based multi-layer resource management framework.

Extending Families: The Social Networks of Parents and their Children.

Foreword U. Bronfenbrenner Preface Part I. Ideas and Themes: 1. Personal networks in the ecology of human development M. Cochran Part II. Settings, Methods and Illustrations: 2. Settings and methods D. Riley et al 3. The social networks interview L. Gunnarsson 4. Descriptive illustrations M. Cochran and C. R. Henderson, Jr. Part III. The Influences of Race, Class and Culture: 5. Social networks, race and ethnicity W. E. Cross, Jr 6. The social networks of married mothers in four cultures M. Cochran et al 7. The social support networks of single parents: Sweden and the United States M. Cochran and L. Gunnarsson Part IV. Impacts on Perceptions and Performance: 8. Network influences upon perception of the child: solo parenting and social support M. Cochran and C. R. Henderson, Jr. 9. Network influences on father involvement in childrearing D. Riley 10. The social networks of six-year-olds: context, content and consequence M. Cochran and D. Riley Part V. Changes in Networks Over Time: 11. Changes in network resources and relationships over time M. Larner 12. Local residential mobility and its effects on social networks: a cross-cultural comparison M. Larner 13. Formal supports and informal social ties: a case study M. Cochran and C. R. Henderson, Jr. Part VI. Social Networks and Human Development: 14. The network as an environment for human development M. Cochran 15. Environmental factors constraining network development M. Cochran 16. Factors influencing personal social initiative M. Cochran 17. Personal networks and public policy M. Cochran Appendix 1. The social network interviews Endnotes References.