Adaptive Bandwidth Allocation Scheme Research Articles

QoS-Guaranteed Adaptive Bandwidth Allocation for Mobile Multiuser Scalable Video Streaming

Bandwidth allocation plays an important role to guarantee the quality of service (QoS) in streaming real-time scalable video to multiuser over wireless time-varying channels. In this letter, an adaptive bandwidth allocation (ABA) scheme is presented to maximize the bandwidth utilization while provisioning each individual user’s QoS. Cooperated with traffic rate adaptation, it jointly addresses the spatial diversity among multiuser and the temporal fluctuation of the individual channel condition. A continuous-time Markov decision processes model is introduced to formulate the QoS-guaranteed ABA problem as constrained stochastic optimization. Based on performance sensitivity analysis, a policy iteration algorithm is developed to find the optimal ABA policy online without any prior knowledge of channel statistics. The adaptability to unknown environments and high computation efficiency make it feasible to implement in running-time. Simulations results demonstrate the effectiveness of the proposed method.

Adaptive filterbank-based multi-carrier waveform design for flexible data rates

Filterbank-based multicarrier (FBMC) scheme is one of the candidate waveforms to handle possible problems in next-generation communication systems, such as high out-of-band (OOB) emission and large peak-to-average power ratio (PAPR). In LTE (Long Term Evaluation), the frequency spectrum is shared by users with pre-defined bandwidths (i.e., 1,4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz), which is not a flexible solution for users having different data rate demands. Similarly, in conventional FBMC systems, bandwidth is divided into equal subbands. Recent studies on FBMC modulation have not provided an effective remedy for such users. Motivated by this requirement, we propose a novel FBMC waveform design that allows an adaptive bandwidth allocation scheme. Accordingly, users will not be restricted to the specified bandwidth schedules. In the paper, subband-based and subcarrier based filtering models are constructed with polyphase filter structures. The proposed structures are realized analytically and tested through computer simulations for different scenarios.

Real-Time Data Delivery Using Prediction Mechanism in Mobile Environments

Mobile data delivery is a critical issue in the mobile computing area. One of the most important problems is the efficient access to data. A proposed solution to this problem is the prefetching technique which consists in putting in reserving the information before the users need it. Low bandwidth, unreliable wireless links, and frequent disconnections of mobile environments make it difficult to satisfy the timing requirements of traditional strategies. This paper investigates broadcast scheduling strategies for push-based broadcast with timing constraints in the form of deadlines ,and proposes a prediction algorithm based on Kalman filter theory for this study. The proposed dissemination policy and adaptive bandwidth allocation scheme obtain sufficient conditions such that all the time-bounded traffic sources satisfy their timing constraints to provide various quality of service guarantees in the broadcast period. Our goal is to identify scheduling algorithms for broadcast systems that ensure requests meeting their deadlines. Our approach examines the performance of traditional real-time strategies and mobile broadcasting strategies, and demonstrates that traditional real-time algorithms do not always perform the best in mobile environments. The proposed design indeed achieves good performance in mobile environments.

An Efficient Admission Control with Adaptive Band Width Allocation Scheme for WCDMA Network

An adaptive B.W allocation scheme is necessary for the QoS provision in WCDMA environment. Traffic in the upcoming wireless network is expected to be extremely non stationary and next generation wireless networks including 3rd generation are expected to provide a wide range of multimedia services with different QoS constraints on mobile communication. Most important issues that the guarantee system efficiency and QoS required for different services. In a many scare resources as the radio spectrum. In this paper we propose WCDMA architecture for multilevel QoS services like voice, video and data for multiple uses and the adaptive B.W allocation scheme for multiuse’s adjusted dynamically according to required network. By simulation result our proposed WCDMA architecture along with B.W allocation scheme will reduce the call blocking probability, through put, transmission time, degraded B.W, degradation ratio. Keywords: wireless network, admission control, through put, QoS, multiclass, transmission time.

Agent-Based Adaptive Bandwidth Allocation in Wireless Networks

Services provided over wireless networks are growing at a rapid pace with the increasing number of users and their demands. Some of the services demand real-time multimedia communication and stringent bandwidth requirements owing to their varied service characteristics. Thus, there is a requirement for developing efficient bandwidth allocation schemes to achieve acceptable Quality of Service (QoS) and meet these challenges. Bandwidth is the most critical resource in wireless networks, which should be managed efficiently. This paper proposes an agent based adaptive bandwidth allocation scheme that allocates the bandwidth by using an interference bandwidth allocation algorithm in cellular system. Proposed scheme claims an agent based bandwidth allocation delay of 24.5 microseconds as opposed to 78 microseconds with non-agent based approach.

QoS-aware bandwidth allocation and admission control in IEEE 802.16 broadband wireless access networks: A non-cooperative game theoretic approach

In this paper, we propose an adaptive bandwidth allocation and admission control mechanism based on game theory for IEEE 802.16 broadband wireless networks. A non-cooperative two-person non-zero-sum game is formulated where the base station and a new connection are the players of this game. The solution of the game formulation provides not only the decision on accepting or rejecting a connection, but also the amount of bandwidth allocated to a new connection (if admitted). A queueing model considering adaptive modulation and coding in the physical layer is used to analyze quality of service (QoS) performances, namely, the delay performance for real-time and the throughput performance for non-real-time polling services and best effort service. This queueing model is used by the proposed bandwidth allocation and admission control mechanism to ensure that the utilities for both the base station and the new connection are maximized. The performance of the proposed scheme is evaluated by simulation and compared with that of each of the traditional admission control with static and adaptive bandwidth allocation schemes.

Radio resource management games in wireless networks: an approach to bandwidth allocation and admission control for polling service in IEEE 802.16 [Radio Resource Management and Protocol Engineering for IEEE 802.16

Game theory is a mathematical tool developed to understand competitive situations in which rational decision makers interact to achieve their objectives. Game theory techniques have recently been applied to various engineering design problems in which the action of one component impacts (and perhaps conflicts with) that of any other component. In particular, game theory techniques have been successfully used for protocol design and optimization (e.g., radio resource management, power control) in wireless networks. In this article we present an overview of different game theory formulations. Then a survey on the game-theory-based resource management and admission control schemes in different wireless networks is presented, and several open research issues are outlined. To this end, we propose an adaptive bandwidth allocation and admission control scheme for polling service in an IEEE 802.16-based wireless metropolitan area network. A noncooperative game is formulated, and the solution of this game is determined by the Nash equilibrium for the amount of bandwidth offered to a new connection. The admission control policy ensures QoS for all connections in the system

An adaptive bandwidth allocation scheme with preemptive priority for integrated voice/data mobile networks

This paper presents an adaptive bandwidth allocation scheme, called complete sharing with preemptive priority (CSPP) scheme, for integrated voice/data mobile networks. It uses the complete sharing approach to maximize the bandwidth utilization efficiency by allowing data traffic to share all the bandwidth resource of a cell and introduces a preemptive priority mechanism to maintain the high performance of voice traffic while the injury of data traffic is compensated through a victim buffer. A degradation/compensation mechanism is applied to the data traffic which has elastic characteristics. The model of the CSPP scheme is analyzed by a two dimensional Markov process. The steady state probability vector is obtained recursively by the matrix-analytic method and many important performance measures are then determined such as different types of probabilities, total channel utilization, transmission delay, busy period time and blocking period time. From the performance analysis and comparison as well as the numerical results, we can conclude that the CSPP scheme can achieve complete service differentiation for different traffic classes and very high and stable channel utilization under various traffic loads. By adjusting the defined constraint factors, we can not only maintain higher priority for handoff voice over new voice calls and voice calls over data calls but also provide necessary protection for data calls in hot-spot data traffic situations

An adaptive bandwidth allocation scheme with preemptive priority for integrated voice/data mobile networks

This paper presents an adaptive bandwidth allocation scheme, called complete sharing with preemptive priority (CSPP) scheme, for integrated voice/data mobile networks. It uses the complete sharing approach to maximize the bandwidth utilization efficiency by allowing data traffic to share all the bandwidth resource of a cell and introduces a preemptive priority mechanism to maintain the high performance of voice traffic while the injury of data traffic is compensated through a victim buffer. A degradation/compensation mechanism is applied to the data traffic which has elastic characteristics. The model of the CSPP scheme is analyzed by a two dimensional Markov process. The steady state probability vector is obtained recursively by the matrix-analytic method and many important performance measures are then determined such as different types of probabilities, total channel utilization, transmission delay, busy period time and blocking period time. From the performance analysis and comparison as well as the numerical results, we can conclude that the CSPP scheme can achieve complete service differentiation for different traffic classes and very high and stable channel utilization under various traffic loads. By adjusting the defined constraint factors, we can not only maintain higher priority for handoff voice over new voice calls and voice calls over data calls but also provide necessary protection for data calls in hot-spot data traffic situations

Fuzzy-Based Adaptive Bandwidth Control for Loss Guarantees

This paper presents the use of adaptive bandwidth control (ABC) for a quantitative packet loss rate guarantee to aggregate traffic in packet switched networks. ABC starts with some initial amount of bandwidth allocated to a queue and adjusts it over time based on online measurements of system states to ensure that the allocated bandwidth is just enough to attain the specified loss requirement. Consequently, no a priori detailed traffic information is required, making ABC more suitable for efficient aggregate quality of service (QoS) provisioning. We propose an ABC algorithm called augmented Fuzzy (A-Fuzzy) control, whereby fuzzy logic control is used to keep an average queue length at an appropriate target value, and the measured packet loss rate is used to augment the standard control to achieve better performance. An extensive simulation study based on both theoretical traffic models and real traffic traces under a wide range of system configurations demonstrates that the A-Fuzzy control itself is highly robust, yields high bandwidth utilization, and is indeed a viable alternative and improvement to static bandwidth allocation (SBA) and existing adaptive bandwidth allocation schemes. Additionally, we develop a simple and efficient measurement-based admission control procedure which limits the amount of input traffic in order to maintain the performance of the A-Fuzzy control at an acceptable level.

Time-aware utility-based resource allocation in wireless networks

This paper presents a time-aware admission control and resource allocation scheme in wireless networks in the context of a future generation cellular network. The quality levels (and their respective utility) of different connections are specified using discrete resource-utility (R-U) functions. The scheme uses these R-U functions for allocating and reallocating bandwidth to connections, aiming to maximize the accumulated utility of the system. However, different applications react differently to resource reallocations. Therefore, at each allocation time point, the following factors are taken into account: the age of the connection, a disconnection (drop) penalty, and the sensitiveness to reallocation frequency. The evaluation of our approach shows a superior performance compared to a recent adaptive bandwidth allocation scheme (RBBS). In addition, we have studied the overhead that performing a reallocation imposes on the infrastructure. To minimize this overhead, we present an algorithm that efficiently reduces the number of reallocations while remaining within a given utility bound.

Quality-of-service provisioning system for multimedia transmission in IEEE 802.11 wireless LANs

IEEE 802.11, the standard of wireless local area networks (WLANs), allows the coexistence of asynchronous and time-bounded traffic using the distributed coordination function (DCF) and point coordination function (PCF) modes of operations, respectively. In spite of its increasing popularity in real-world applications, the protocol suffers from the lack of any priority and access control policy to cope with various types of multimedia traffic, as well as user mobility. To expand support for applications with quality-of-service (QoS) requirements, the 802.11E task group was formed to enhance the original IEEE 802.11 medium access control (MAC) protocol. However, the problem of choosing the right set of MAC parameters and QoS mechanism to provide predictable QoS in IEEE 802.11 networks remains unsolved. In this paper, we propose a polling with nonpreemptive priority-based access control scheme for the IEEE 802.11 protocol. Under such a scheme, modifying the DCF access method in the contention period supports multiple levels of priorities such that user handoff calls can be supported in wireless LANs. The proposed transmit-permission policy and adaptive bandwidth allocation scheme derive sufficient conditions such that all the time-bounded traffic sources satisfy their time constraints to provide various QoS guarantees in the contention free period, while maintaining efficient bandwidth utilization at the same time. In addition, our proposed scheme is provably optimal for voice traffic in that it gives minimum average waiting time for voice packets. In addition to theoretical analysis, simulations are conducted to evaluate the performance of the proposed scheme. As it turns out, our design indeed provides a good performance in the IEEE 802.11 WLAN's environment, and can be easily incorporated into the hybrid coordination function (HCF) access scheme in the IEEE 802.11e standard.

Predictive call admission control for multimedia streaming in CDMA cellular environments

Third-generation (3G) wireless networks based on code-division multiple access (CDMA) have been engineered to provide mobile users with voice as well as advanced packet data services. Support of Internet-based multimedia streaming services is considered a critical factor for future deployment of such networks. Provisioning streaming services in a dependable way, however, requires supporting data transmission at relatively high data rates while maintaining session quality during both intracell and intercell user movements. In this paper, an adaptive bandwidth allocation and admission control scheme is proposed for managing network resources for a streaming service. Streaming requests are assumed to be served by an adaptive server capable of choosing suitable video streaming parameters (e.g., video resolution, frame rate, and encoding parameters) in response to possible requests from the wireless network to vary the currently allocated bandwidth. The devised admission control scheme exploits a priori knowledge of user mobility patterns to minimize the risk of running into an overload condition after acceptance of a new multimedia streaming connection. The obtained simulation results show that, compared to a nonpredictive admission control scheme, the proposed scheme achieves a lower forced-termination probability and higher throughput, while consuming less base-station transmission energy.

An agent based adaptive bandwidth allocation scheme for multimedia applications

Bandwidth allocation for multimedia applications in case of network congestion and failure poses technical challenges due to bursty and delay sensitive nature of the applications. The growth of multimedia services on Internet and the development of agent technology have made us to investigate new techniques for resolving the bandwidth issues in multimedia communications. Agent technology is emerging as a flexible promising solution for network resource management and QoS (Quality of Service) control in a distributed environment. In this paper, we propose an adaptive bandwidth allocation scheme for multimedia applications by deploying the static and mobile agents. It is a run-time allocation scheme that functions at the network nodes. This technique adaptively finds an alternate patchup route for every congested/failed link and reallocates the bandwidth for the affected multimedia applications. The designed method has been tested (analytical and simulation) with various network sizes and conditions. The results are presented to assess the performance and effectiveness of the approach. This work also demonstrates some of the benefits of the agent based schemes in providing flexibility, adaptability, software reusability, and maintainability.

An adaptive measured-based preassignment scheme with connection-level QoS support for mobile networks

This paper presents a new adaptive bandwidth allocation scheme to prevent handoff failure in wireless cellular networks, known as the measurement-based preassignment (MPr) technique. This technique is particularly useful in micro/pico cellular networks which offers quality-of-service (QoS) guarantee against call dropping. The proposed MPr scheme distinguishes itself from the well-known guarded channel (GC) based schemes in that it allows the handoff calls to utilize a prereserved channel pool before competing for the shared channels with new call arrivals. The key advantage of the proposed MPr scheme is that it enables easy derivation of the number of channels that needs to be reserved for handoff based on a predetermined handoff dropping probability, without the need for solving the often complex Markov chain required in GC schemes, thus, making the proposed MPr scheme simple and efficient for implementation. This is essential in handling multiple traffic types with potentially different QoS requirements. In addition, the MPr scheme is adaptive in that it can dynamically adjust the number of reserved channels for the handoff according to the periodical measurement of the traffic status within a local cell, thus completely eliminating the signaling overhead for status information exchange among cells mandated in most existing channel allocation schemes. Numerical results and comparisons are given to illustrate the tradeoff.

Adaptive bandwidth allocation based on playback tunnel to support video on demand service over ATM networks

This paper focuses on adaptive bandwidth allocation (ABA) for transporting pre-stored VBR compressed video data across networks in support of video-on-demand (VoD) service. Two key issues are addressed. Firstly, a simplified dynamic programming method based on playback tunnel is proposed to predict the bandwidth which can be dynamically allocated for transporting video segment to guarantee that the playback buffer neither underflows nor overflows. Secondly, ABA schemes with different criteria including middle-tunnel ABA (MT-ABA) and reduced-bandwidth-variability ABA (RBV-ABA) are investigated. The proposed ABA schemes are evaluated by a set of real-life MPEG video traces. The obtained results show that the RBV-ABA scheme outperforms MT-ABA scheme in terms of peak rate, traffic burstiness and bandwidth variability. On the other hand, the MT-ABA scheme is more significant for avoiding the playback buffer overflow or underflow than that of RBV-ABA.

An efficient and adaptive bandwidth allocation scheme for mobile wireless networks using an on-line local estimation technique

The next generation of mobile wireless networks has to provide the quality-of-service (QoS) for a variety of applications. One of the key generic QoS parameters is the call dropping probability, which has to be maintained at a predefined level independent of the traffic condition. In the presence of bursty data and the emerging multimedia traffic, an adaptive and dynamic bandwidth allocation is essential in ensuring this QoS. The paradox, however, is that all existing dynamic bandwidth allocation schemes require the prior knowledge of all traffic parameters or/and user mobility parameters. In addition, most proposals require extensive status information exchange among cells in order to dynamically readjust the control parameters, thus making them difficult to be used in actual deployment. In this paper, we introduce a novel adaptive bandwidth allocation scheme which estimates dynamically the changing traffic parameters through local on-line estimation. Such estimations are restricted to each individual cell, thus completely eliminating the signaling overhead for information exchange among cells. Furthermore, we propose the use of a probabilistic control policy, which achieves a high channel utilization, and leads to an effective and stable control. Through simulations, we show that our proposed adaptive bandwidth allocation scheme can guarantee the predetermined call dropping probability under changing traffic conditions while at the same time achieving a high channel utilization.

A nonpreemptive priority-based access control scheme for broadband ad hoc wireless ATM local area networks

The DQRUMA (distributed-queueing request update multiple access) protocol has been considered as an access protocol for the BAHAMA (broadband ad hoc wireless ATM local area network). However, it cannot support the service discipline of integrated multimedia traffic since it does not include any priority and access control policy. In this paper, we propose a nonpreemptive priority-based access control scheme for the DQRUMA protocol. Under such a scheme, modifying the CSMA/CA protocol in the contention period supports many levels of priorities such that user mobility (handoff) can be supported in BAHAMA. Besides, the proposed transmit-permission policy and adaptive bandwidth allocation scheme provide various QoS (quality-of-service) guarantees while maintaining high bandwidth utilization. Simulations show that it provides a good performance in ad hoc wireless ATM LAN environments.

A dynamic bandwidth control scheme of VP in ATM networks

This paper proposes an efficient adaptive bandwidth allocation scheme of virtual paths. The bandwidth of a virtual path is dynamically adjusted according to the link residual capacity. The scheme can remarkably reduce the load on node processing and simplify the network architecture, while keeping higher transmission efficiency. The excellent performance is proved by detailed theoretical analyses.