Modeling QoS degradation in multimedia wireless networks

In wireless networks carrying multimedia traffic, it becomes necessary to provide a quality of service (QoS) guarantee for multimedia traffic connections. A novel timing-based bandwidth allocation protocol is proposed as a solution to support QoS guarantees in the multimedia wireless networks. Based on the existing network conditions, the proposed scheme makes an adaptive decision for bandwidth reservation and call admission by employing fuzzy inference mechanism, timing based reservation strategy, and round-borrowing strategy in each base station. The amount of reserved bandwidth for each base station is dynamically adjusted, according to the online traffic information of each base station. Simulation results show that our timing-based bandwidth reservation scheme outperforms the previous schemes in terms of connection-blocking probability, connection-dropping probability, and bandwidth utilization.

Bandwidth degradation QoS provisioning for adaptive multimedia in wireless/mobile networks

The balanced distribution of multimedia wireless network modular teaching resources is improved by optimizing and adjusting the balanced distribution of multimedia wireless network modular teaching resources. Based on block grid balanced scheduling and resource spectrum fusion, a balanced distribution method of multimedia wireless network modular teaching resources is proposed. A blockchain Internet of Things accesses control network architecture system for the balanced allocation of multimedia wireless network modular teaching resources established using the priority business scheduling method. Modular resource allocation of multimedia wireless networks and adaptive forwarding are adjusted to control the data packets. The bandwidth guarantee mechanism is used for the equitable allocation of multimedia wireless network modular teaching resources information flow. Multi-service hierarchical management of multimedia wireless network modular teaching resources spectrum is controlled by block grid balanced scheduling and resource spectrum fusion. The high-energy physical computing system structure is used to allocate the resource spectrum balance of the modular teaching resources of the multimedia wireless networks, ensuring the bandwidth requirements of various services. The classified management and balanced allocation of the multimedia wireless networks’ teaching storage, system, and teaching spectrum resources are made possible. The results of the tests show that this method effectively reduces the delay in the allocation of modular multimedia wireless network teaching resources, improves the utilization rate of modular multimedia wireless network teaching resources, and significantly improves their reading and writing performance.

In this paper, a dynamic and adaptive bandwidth management scheme is proposed to provide as satisfactory quality-of-service (QoS) guarantee as possible for wireless multimedia services under variable traffic conditions. Under the highly variable wireless environment, the existing bandwidth management schemes result in more frequent quality changes for active flows than necessary, which are undesirable and intolerant to multimedia real-time applications. The proposed scheme is designed to provide high bandwidth utilization efficiency and low call blocking probability with minimum QoS fluctuation. In order to minimize the impact of bandwidth change for the QoS of existing flows, a controlled bandwidth degradation algorithm is performed when the free bandwidth in a cell isn't enough to admit a new flow. Compared with existing schemes, our scheme reduces the probability of frequent quality changes and provides more satisfactory services for higher priority flows. The performance analysis has shown that, under the same network load, our proposed scheme outperforms existing ones with lower QoS degradation probability.

Dynamic rate-based borrowing scheme for QoS provisioning in high speed multimedia wireless cellular networks

This paper presents two novel heuristic algorithms for the design of wireless access multimedia networks. Emphasis was given to the design of CDMA based wireless multimedia networks and fixed wireless multimedia networks. The objectives of these methods are first to place a number of access points/base stations in a number of candidate sites and then to assign a number of fixed wireless terminals to the selected access points/base stations. Both methods are based on graph theory and they are essentially greedy algorithms. Except from capacity constraints, wireless reception characteristics are also considered. The algorithms are capable of designing medium and large-scale networks at polynomial time. Both algorithms were compared with an analogous optimisation problem through a series of tests. The results indicate that as regards design costs the performance of the heuristics is very close to this of the equivalent optimisation problem. The solution times for the heuristics are smaller especially when the number of the candidate access points/base stations becomes large

Adaptive call admission control for QoS provisioning in multimedia wireless networks

An important quality-of-service (QoS) issue in wireless multimedia networks is how to control handoff drops. We propose admission-control algorithms that adaptively control the admission threshold in each cell in order to keep the handoff-dropping probability below a predefined level. The admission threshold is dynamically adjusted based on handoff-dropping events. We first present a simple admission-control scheme that brings out an important performance evaluation criterion - intercell fairness - and serves as a reference point. We then investigate the intercell unfairness problem and develop two enhanced schemes to overcome this problem. The performance of these protocols is benchmarked and compared with other competitive schemes. The results indicate that our schemes perform very well while, in addition, achieving significantly reduced complexity and signaling load.

A set of centralized burst-level cell scheduling schemes, namely, First Come First Served with Frame Reservation (FCFS-FR), FCFR-FR+, Earliest Deadline First with Frame Reservation (EDF-FR), EDF-FR+, and Multitraffic Dynamic Reservation (MTDR), are investigated for transmission of multiservice traffic over time division multiple access (TDMA)/time division duplex (TDD) channels in wireless ATM (WATM) networks. In these schemes, the number of time slots allocated to a virtual circuit (VC) during a frame-time is changed dynamically depending on the traffic type, system traffic load, the time of arrival (TOA)/time of expiry (TOE) value of the data burst and data burst length. The performances of these schemes ate evaluated by computer simulation for realistic voice, Video and data traffic models and their quality-of-service (QoS) requirements in a wireless mobile multimedia network. Both the error-free and the correlated fading channel conditions are considered. Simulation results show that the EDF-FR+ and MTDR schemes outperform the other schemes and can provide high channel utilization with predictive QoS guarantee in a multiservice traffic environment even in the presence of bursty channel errors. The EDF-FR+ scheme is found to provide better cell multiplexing performance than the MTDR scheme. Such a scheme would be easy to implement and would also result in a power conservative TDMA/TDD medium access control (MAC) protocol for broadband wireless access. Burst-level cell scheduling schemes such as EDF-FR+ can be easily adapted as MAC protocols in the emerging differentiated services (DS) enhanced wireless Internet protocol (IP) networks.

Next generation wireless networks target to provide quality of service (QoS) for multimedia applications. In this paper, the system supports two QoS criteria, i.e., the system should keep the handoff dropping probability always less than a predefined QoS bound, while maintaining the relative priorities of different traffic classes in terms of blocking probability. To achieve this goal, a dynamic multiple-threshold bandwidth reservation scheme is proposed, which is capable of granting differential priorities to different traffic class and to new ad handoff traffic for each class by dynamically adjusting bandwidth reservation thresholds. Moreover, in times of network congestion, a preventive measure by use of throttling new connection acceptance is taken. Another contribution of this paper is to generalize the concept of relative priority, hence giving the network operator more flexibility to adjust admission control policy by incorporating some dynamic factors such as offered load. The elaborate simulation is conducted to verify the performance of the scheme.

Next generation wireless communication systems target to provide guaranteed quality of service (QoS) for multimedia applications. In this paper, a multiple-threshold bandwidth reservation scheme combined with a call admission control algorithm is proposed and analyzed. The objective of our work is to be able to achieve better QoS provisioning for mobile users while achieving efficient utilization of the available limited bandwidth. The proposed scheme is modelled as M/M/C/C queueing system and the performance measures, call blocking probability and call dropping probability are computed. The performance of our scheme is compared to the complete sharing (CS) policy. Simulation results show that our scheme surpasses the CS policy in terms of call blocking probability, call dropping probability and bandwidth utilization.

The significantly increased density of pins of stan-dard cells and the reduced number of routing tracks at sub-10nm nodes have made the pin access problem in detailed routing very difficult. To alleviate this pin accessibility problem in detailed routing, recent works have proposed to make a small perturbation of cell shifting, cell flipping, and adjacent cells swapping in the detailed placement stage. Here, an essential element for the success of pin accessibility aware detailed placement is the installed cost function, which should be sufficiently accurate in predicting the degree of routing difficulty in accessing pins. In this work, we propose a new model of cost function that is comprehensively devised to overcome the limitations of the prior ones. Precisely, unlike the conventional cost functions, our proposed cost function model is based on the empirical routing data in order to fully reflect the potential outcomes of detailed routing. Through experiments with benchmark circuits, it is shown that using our proposed cost function in detailed placement is able to reduce the routing errors by 44 % on average while using the existing cost functions reduce the routing errors on average by at most 15 %.

IPv6 has gained its common sense as a fundamental IP instruction for the next generation network with larger address space with better QoS (Quality of Service) service. The IPv6 FL (flow label) is a function that, as it was designed, can be a big help in alleviating QoS problem from flow level treatment. However, the original design of FL can easily induce scalability problem and it has not been used yet. In this paper, we make a first step to investigate FL as a network layer QoS mechanism for heterogeneous network. Our proposed end-to-end QoS solution can get rid of scalability problem, while keeping the ability of flow-based QoS treatment. The main contribution of this paper is threefold: First, we attempt to provide an analysis of FL-related definitions, and subsequently propose a modified IPv6 FL specification, with which IPv6 can have get the underlying feature of powerful QoS management ability like ATM, but keep the simplicity of native IP. Second, we propose a FL-QCM (FL-based QoS class mapping) method for heterogeneous network. FL-QCM is a novel way to deal with QoS class mapping for inter-domain QoS guarantee and is more flexible and scalable for future use. Third, the detailed FL generation, maintenance mechanism has been proposed for inter-domain solution. Our proposed model has been implemented in OPNET and it can get better QoS performance than existing technology.

Next-generation wireless networks have been designed to transport integrated multimedia services based on a cellular extension of a packet-switched architecture using variants of the Internet protocol (IP). Each call, arriving to or active within the network, carries demand for one or more services in parallel, where each service type has a guaranteed quality of service (QoS). Admission of new calls to the wireless IP network (WIN) from the gateway of a wired network or from a mobile subscriber (MS) is allowed by call admission control (CAC) procedures. MS roaming among the nodes of the WIN is controlled by handoff procedures between base stations (BSs), or BS controllers (BSCs), and the MSs. Both handoff and CAC procedures are typically embedded in the media access control (MAC) and logical link control (LLC) layers of the WIN protocol stack. Performance metrics, such as, probabilities of call blocking and handoff, control procedures within the WIN protocol. Earlier published results by the author present a method for the performance analysis of wireless multimedia networks based on multivariate point-process (MVPP) models and their semi-martingale representations. The models describe the finite-horizon, transient behavior of the packet flows in integrated multimedia traffic. This paper extends the earlier work to focus on the optimization of real-time control procedures embedded in the WIN protocol stack. The point processes corresponding to the packet flow of each service type and to collateral random network events are decomposed into right-continuous, pure jump processes and predictable, integrated random rate processes. Control of the set of point processes describing WIN behavior is implemented through the construction of an absolutely continuous change of a reference probability measure on network events to a controlled measure. With respect to the constructed controlled measure, the integrated random rates in the semi-martingale representations of the network point processes explicitly depend on the parameters of the protocol mechanisms for packet access, routing, switching, handoff, power control, and other resource allocations. The MVPP control approach via constructed probability measure also supports predictive models of packet flows that incorporate measurement-based estimates of the probability distributions for voice, video, data, and other Internet traffic as well as radio path distortions. Optimization of the performance metrics, represented in terms of the MVPPs and the control parameters of candidate WIN protocols for multimedia services, are discussed for both partial and complete observations of network events. The models are further used to develop optimal, recursive stochastic filters of network state, based on partial or incomplete observations of packet flow dynamics.

With the rapid growth of functionally identical web services, Quality of Service (QoS) plays vital role for deciding the most suitable services for consumers. Although, QoS for web services has gained extensive attention in the literature, most of the existing efforts are unable to consider the multiperspective QoS of web services. Unlike conventional software paradigms, web services are provided, developed and used by different users such as provider, consumer and broker. As a result, QoS requirements vary from user to user. Existing researches are unable to provide standard solution, which can deal with what service providers, consumers and broker should expose in service description as QoS parameters. Therefore, in this book chapter, a multiperspective PCB-QoS classification of non-functional parameters along with new QoS parameters, i.e. access rate and Overall Aggregated Effective Quality of Service (OAEQoS) is presented. Due to the extensible nature of PCB-QoS classification, it can be extended to accommodate more number of QoS parameters. This QoS classification is based on the idea of partitioning the generic QoS parameters according to multi-user’s perspective. An Average Real Value Sum Method (ARSM) based on default priority constraints is also proposed for ranking of web services that uses the presented QoS classification. With the help of proposed approach, the user can specify the service requirements without taking the hurdle of specifying the weights for each QoS parameter during web service operations. It also prevents the services from malicious service provider to publish the incorrect and inaccurate QoS information. Experimental evaluation shows the effectiveness of proposed approach over the existing approach.