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

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.

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.

Presently, the wireless mobile networks and devices are becoming increasingly popular to provide users the access anytime and anywhere. The mobile systems are based on cellular approach and the area is covered by cells that overlap each other. Many handover algorithms are proposed in the literature. However, to make a better handover and keep the QoS in wireless networks is very difficult. In this paper, we propose a new handover system based on fuzzy logic. We consider the case of handover enforcement and verify that the proposed system makes the necessary handovers for all simulations.KeywordsMobile StationFuzzy Logic ControllerRandom Walk ModelFuzzy Rule BaseVertical HandoffThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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.

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.

Many handover algorithms are proposed in the literature. However, to make a better handover and keep the QoS in wireless networks is very difficult. In this paper, we propose a new handover system based on fuzzy logic. The proposed system uses 3 parameters for handoff decision: the change of signal strength of the present Base Station (BS), signal strength from the neighbor BS, and the distance between Mobile Station (MS) and BS. The performance evaluation via simulations shows that proposed system can avoid ping-pong effect and has a good handover decision.

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.

Adaptive bandwidth reservation in wireless cellular networks is expected to ensure bounded call level QoS when network conditions such as new call arrival rates or users' mobilities are changing. The feature of the event based adaptive bandwidth reservation is that bandwidth reservation values are distributed by the target base station to the neighboring base stations upon new call arrivals, handoffs and call terminations. This paper considers the problem of maintaining bounded forced call termination probability under adaptive admission algorithm when the user mobility changes. Our analysis shows that in order to control the forced call termination probability, a bandwidth reservation policy must be imposed on the bandwidth reservation values. Several bandwidth reservation policies have been analysed, and the range of call level QoS has been determined under variable user mobility in all the cases. The analytical results have been validated by simulations.

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.

Wireless multimedia networks are becoming very popular owing to the user demands for multimedia services. Packet dropping in the event of buffer congestion is one of the important issue in wireless multimedia networks. A packet dropping scheme has to be flexible and adaptive such that acceptable quality of an application is maintained. The paper presents a fuzzy based packet dropping scheme for wireless multimedia networks. A buffer manager placed at the base station performs packet dropping depending upon the traffic conditions and type of an application. Packet dropping is performed by computing dropping factor by considering packet priority, queue length and adaptive queue length threshold. The adaptive queue length threshold is used to dynamically adjust the dropping factor. The queue length threshold is varied by using two fuzzy input parameters, channel condition and rate of flow of an application. The scheme has been extensively simulated to test the performance in terms of acceptance and dropping probability of real-time handoff and new calls.

A key issue in wireless multimedia networking regards the coexistence of different services/traffic types over common wireless resources. Research in Transmitter Power Control (TPC) has proposed various schemes for different traffic types without addressing effectively the problem of coexistence. Each of the TPC schemes of the literature is usually (i) unsuitable/inefficient for supporting diverse traffic types, and (ii) incompatible with each other, leading to conflicts if operated over common wireless channels.In this paper, we tackle the problem of coexistence by presenting novel converged TPC schemes. First, we investigate converged TPC schemes for links carrying the two basic traffic types of media streaming circuit-switched/constant-rate traffic (i.e. voice, CBR video), andpacket-switched elastic traffic (i.e. data).Evaluated against conventional TPC algorithms operating in dedicated wireless resources, the proposed schemes are demonstrated to increase the capacity of the wireless network. Second, we explore new hybrid types of traffic that combine the best-effort grade of service adapting to the network conditions with a guaranteed minimum, and propose appropriate TPC schemes.

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.

This paper proposes a novel and efficient distributed flow control for wireless multimedia networks using cooperative communications, based on the Proportional Integral (PI) controllers. The control parameters can be designed to ensure the stability of the control loop in terms of source rate. The distributed explicit rate controller is located at the wireless multimedia sensor source to regulate the transmission rate for mission. We further analyse the theoretical aspects of the proposed algorithm. Simulation results demonstrate the efficiency of the proposed scheme in terms of system stability, fast response, and high efficiency for mission-oriented multimedia systems. Simulation results show that the performance of our scheme is improved more than 10% when compared with other method.

Adaptive call admission control for QoS provisioning in multimedia wireless networks