With the expected prevalence of 11P-based wireless mobile communicationnetworks, the provision of adequate mobility solutions becomes a key issue. The concept of network-based mobility management is currently being d...
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ISBN:
(纸本)9789531841108
With the expected prevalence of 11P-based wireless mobile communicationnetworks, the provision of adequate mobility solutions becomes a key issue. The concept of network-based mobility management is currently being debated on by the Internet Engineering Task Force as a novel approach enabling mobility for user terminals which lack built-in mobility extensions. Such a concept provides an alternative to the conventional host-based solutions. In this paper, we investigate the corresponding requirements, and analyze three proposed schemes for network-based IP mobility management. The operational mechanisms defined in the Proxy Mobile IPv4, Proxy Mobile IPv6, and the Network-Based Localized Mobility Management Protocol (NBLM) schemes are qualitatively compared based on performance, security and deployment aspects in order to provide a better understanding of the bene its an shortcomings of the network-based mobility concept. The resulting evaluation is aimed at determining the possibilities for an optimized architecture model and feasible performance improvements.
Vis-a-vis the State-of-the-Art we illustrate how our approach to opportunistic communications tackles the major challenges in next-generation Internet architecture.
ISBN:
(纸本)9781424408269
Vis-a-vis the State-of-the-Art we illustrate how our approach to opportunistic communications tackles the major challenges in next-generation Internet architecture.
In this paper we propose novel optimization models for the planning of Wireless Mesh networks whose objective is to minimize the network installation cost, while providing full coverage to wireless mesh clients. Our m...
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ISBN:
(纸本)97830540726050
In this paper we propose novel optimization models for the planning of Wireless Mesh networks whose objective is to minimize the network installation cost, while providing full coverage to wireless mesh clients. Our mixed integer linear programming models aim at selecting the number and positions of mesh routers and access points, while taking into account in an accurate way traffic routing, interference, rate adaptation, and channel assignment. We provide the optimal solutions of the proposed problem formulations on a set of realistic-size instances and discuss the effect of different parameters on the characteristics of the planned networks.
This paper focuses on the design of IBGP networks, which are very important to the reliability and stability of Internet. Although several metrics have been presented to measure the robustness of IBGP networks, they o...
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ISBN:
(纸本)97830540726050
This paper focuses on the design of IBGP networks, which are very important to the reliability and stability of Internet. Although several metrics have been presented to measure the robustness of IBGP networks, they only considered the impact of route reflection networks on the control plane. A robust network should have low sensitivity to traffic load variations. So we propose a new metric to characterize the impact of route reflection networks on the data plane, which is called TDR (Traffic Diversion Rate). Simulation results show that adopting the optimal route reflection topology that minimizes TDR will make the network lose or shift Much less traffic, compared with adopting the optimal route reflection topologies found according to other metrics.
The increased deployment of wireless mesh networks (WMNs) should be complemented by a robust resource management scheme that can provide performance guarantees to mission-critical applications. Several admission contr...
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ISBN:
(纸本)9781424414543
The increased deployment of wireless mesh networks (WMNs) should be complemented by a robust resource management scheme that can provide performance guarantees to mission-critical applications. Several admission control schemes have been presented for wireless LANs and wireless ad-hoc networks. However, wireless mesh networks, with static wireless back-bone and multihop communication, pose new design challenges. Evaluation of existing admission control schemes has been done primarily via simulations, which often do not have accurate models for capturing interference between adjacent wireless links and nodes. In this paper, we develop light-weight monitoring modules to measure current network/traffic conditions and estimate end-to-end path delay, which is then incorporated in our admission control decision. We Utilize a novel layer-2 packet forwarding mechanism, based on the Wireless Distribution System (WDS) for WMNs. We evaluate our scheme via experiments conducted on a testbed consisting of IEEE 802.11a-based nodes that form a wireless mesh. Results show that our proposed scheme can provide performance assurance without incurring too much control overhead.
Expected benefits of smart home telecare services do still depend on the capability to develop and validate systems which may foresee or react in an intelligent way to situations demanding specific support to patients...
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ISBN:
(纸本)0769530486
Expected benefits of smart home telecare services do still depend on the capability to develop and validate systems which may foresee or react in an intelligent way to situations demanding specific support to patients, informal carers or authorized staff. Together with wireless sensornetworks or broadband communication infrastructures at home, it is needed to create models and methods to solve how a smart home might think and act in identified home care contexts. This research work provides and implementation framework, supported by knowledge based techniques, that permits to design, develop and validate the description logic of a smart home telecare service. The framework includes an adapted methodology to sustain the knowledge acquisition process from users and experts as well as the creation and integration of ontologies in order to facilitate reasoning logic at ad hoc scenarios. The system was validated for a smart home telecare context supporting elderly fall episodes.
In this paper, we consider two fairness problems that occur in the infrastructure network (fairness between TCP uplink/downlink flows and fairness between competing TCP uplink flows). A large number of existing works ...
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ISBN:
(纸本)97830540726050
In this paper, we consider two fairness problems that occur in the infrastructure network (fairness between TCP uplink/downlink flows and fairness between competing TCP uplink flows). A large number of existing works have studied the TCP fairness issues and greatly solved the TCP unfairness problems. However, these solutions suffer from the drawback of TCP throughput degradation even though the TCP unfairness problem can be solved. In order to solve these problems effectively, we propose a scheme that modifies the receiver window size on the basis of maximum window size which is able to maximize link utilization. We have evaluated our scheme with ns-2 simulator and the results demonstrate that our scheme greatly improves both the TCP fairness and total throughput.
We study field-monitoring applications in which sensors are deployed in large numbers and the sensing process is expensive. In such applications, nodes should use the minimum possible sensing ranges to prolong the &qu...
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ISBN:
(纸本)97830540726050
We study field-monitoring applications in which sensors are deployed in large numbers and the sensing process is expensive. In such applications, nodes should use the minimum possible sensing ranges to prolong the "coverage time" of the network. We investigate how to determine such minimum ranges in a distributed fashion when the nodes are location-unaware. We develop a distributed protocol (SRAP) that assigns shorter ranges to nodes with less remaining batteries. To handle location-unawareness, we develop a novel algorithm (VICON) for determining the virtual coordinates of the neighbors of each sensor. VICON relies on approximate neighbor distances and 2-hop neighborhood information. Our simulations indicate that SRAP results in significant coverage time improvement even under inaccurate distance estimation.
Mission-critical networks in support of NATO expeditionary operations demand highly deployable and reliable communication solutions. Emerging WiMAX wireless technology offers valuable benefits for such use cases like ...
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ISBN:
(纸本)9781424415120
Mission-critical networks in support of NATO expeditionary operations demand highly deployable and reliable communication solutions. Emerging WiMAX wireless technology offers valuable benefits for such use cases like non-line of sight operations, extended coverage in point-to-multipoint configuration, adaptive modulation, scheduled media access, and embedded QoS support, to name a few. NC3A has developed a prototype implementation of next-generation deployable communications and Information Systems modules, selecting RedMAX technology to implement a WiMAX communications wireless backbone. The paper describes the unique challenges of a deployable headquarter communications network, the prototype and test-bed concept, and the main characteristics of WiMAX physical layer and MAC layer. It then concentrates on the test and validation of the WiMAX performance NC3A has recently conducted, with a focus on scheduling and QoS features under the context of IP-converged networks carrying multiple types of traffic.
In this paper, we consider multi-hop wireless mesh networks, where each router node is equipped with multiple radio interfaces and multiple channels are available for communication. We address the problem of assigning...
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ISBN:
(纸本)9781424412679
In this paper, we consider multi-hop wireless mesh networks, where each router node is equipped with multiple radio interfaces and multiple channels are available for communication. We address the problem of assigning channels to communication links in the network with the objective of minimizing overall network interference. Since the number of radios on any node can be less than the number of available channels, the channel assignment must obey the constraint that the number of different channels assigned to the links incident on any node is atmost the number of radio interfaces on that node. The above optimization problem is known to be NP-hard. We design centralized and distributed algorithms for the above channel assignment problem. To evaluate the quality of the solutions obtained by our algorithms, we develop a semidefinite program formulation of our optimization problem to obtain a lower bound on overall network interference. Empirical evaluations on randomly generated network graphs show that our algorithms perform close to the above established lower bound, with the difference diminishing rapidly with increase in number of radios. Also, detailed ns-2 simulation studies demonstrate the performance potential of our channel assignment algorithms in 802.11-based multi-radio mesh networks.
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