Resource allocation scheme for QoS provisioning in microcellular networks carrying multimedia traffic

We propose a new resource allocation scheme based on the concept of resource reservation and resource renegotiation. The new scheme is aimed at improving performance with regard to new call blocking rate, handoff dropping rate, forced call termination rate, and average bandwidth use. We compare our scheme with other schemes. The performance is evaluated by using simulation. Copyright © 2001 John Wiley & Sons, Ltd.     

QoS provisioning for multimedia wireless networks

As we move towards IP-based multimedia wireless networks with voice, video and data convergence, quality of service (QoS) provisioning will become an increasingly challenging task. One implication is that greater emphasis on managing the call admission and overall network resources will be needed. This paper presents a conservative and adaptive quality of service (CAQoS) framework for provisioning the QoS for both real-time and non-real-time traffic in a multimedia wireless network. Unlike most conventional schemes, which gradually scale down the bandwidth of ongoing connections to accommodate new connection/hand-off requests, CAQoS introduces an early scaling-down of bandwidth for new connections based on a designated provisioning model. The performance of a CAQoS system is evaluated through simulations of a realistic wireless environment. Simulation results show that CAQoS meets our design goals and outperforms conventional schemes.     

End-to-end QoS provisioning in mobile heterogeneous networks

The remarkable advances in information technologies bring a heterogeneous environment for mobile users and service providers. This heterogeneity exists in wireless access technologies, networks, user terminals, applications, service providers, and so on. The ability to provide seamless and adaptive quality of service in such a heterogeneous environment is key to the success of next-generation wireless communications systems. There has been a considerable amount of QoS research recently. However, the main part of this research has been in the context of individual architectural components, and much less progress has been made in addressing the issue of an overall QoS architecture for the mobile Internet. This article first summarizes the state-of-the-art QoS techniques and standardization activities, then examines in detail important challenges in building a ubiquitous QoS framework over the heterogeneous environment, and finally proposes a QoS framework integrating a three-plane network infrastructure and a unified terminal cross-layer adaptation platform to provide seamless support for future applications.     

An MAC protocol supporting multiple traffic over mobile ad hoc networks

This letter presents the design and performance of a multi-channel MAC protocol that supports multiple traffics for IEEE 802.11 mobile ad-hoc networks.The dynamic channel selection scheme by receiver decision is implemented and the number of the data channel is independent of the network topology.The priority for real-time traffic is assured by the proposed adaptive back off algorithm and different IFS.The protocol is evaluated by simulation and the results have shown that it can support multiple traffics and the performance is better than the performance that IEEE 802.11 standard provides.     

QoS provisioning for multiple non‐real‐time services in cellular wireless networks

Future mobile services are expected to include various non‐voice oriented services. One important category of non‐voice oriented mobile services is non‐real‐time services. When a mobile user establishes a connection to access non‐real‐time service, the mobile user usually cares about whether the total time to complete its data transfer is within its time tolerance. In addition, different mobile users may have different bandwidth requirements and different tolerances in the total completion time. It is essential for wireless systems to provide various mobile users with different total completion times. In this paper, two quality‐of‐service (QoS) metrics, called stretch ratio and eligibility percentage, are employed at a connection level to present the degree of the length of the total completion time. We devise a measurement based call admission control scheme that provides multiple QoSs for various mobile users which have different requirements of stretch ratios, eligibility percentages, and bandwidths. Extensive simulation results show that the measurement based call admission control scheme not only provides various satisfactory QoSs for mobile users but also produces high throughput. Copyright © 2010 John Wiley & Sons, Ltd.     

QoS provisioning in cellular networks based on mobility prediction techniques

In cellular networks, QoS degradation or forced termination may occur when there are insufficient resources to accommodate handoff requests. One solution is to predict the trajectory of mobile terminals so as to perform resource reservations in advance. With the vision that future mobile devices are likely to be equipped with reasonably accurate positioning capability, we investigate how this new feature may be used for mobility predictions. We propose a mobility prediction technique that incorporates road topology information, and describe its use for dynamic resource reservation. Simulation results are presented to demonstrate the improvement in reservation efficiency compared with several other schemes.     

FRR for latency reduction and QoS provisioning in OBS networks

We propose a forward resource reservation (FRR) scheme to reduce the data burst delay at edge nodes in optical burst switching (OBS) systems. We also explore algorithms to implement the various intrinsic features of the FRR scheme. Linear predictive filter (LPF)-based methods are investigated and demonstrated to be effective for dynamic burst-length prediction. An aggressive resource reservation algorithm is proposed to deliver a significant performance improvement with controllable bandwidth cost. By reserving resources in an aggressive manner, an FRR system can reduce both the signaling retransmission probability and the bandwidth wastage as compared with a system without the aggressive reservation. An FRR-based QoS strategy is also proposed to achieve burst delay differentiation for different classes of traffic. Theoretical analysis and simulation results verify the feasibility of the proposed algorithms and show that our FRR scheme yields a significant delay reduction for time-critical traffic without incurring a deleterious bandwidth overhead.     

Resource provisioning for multigranular traffic flows in multilayer networks

The paper deals with the problem of multilayer resource provisioning in a network in which an operator needs to route traffic flows with different data rates. It is shown that the blocking probability of high data rate requests is usually higher than the blocking probability of other requests. A relevant strategy aimed at solving this problem is proposed, investigated, and compared with the known solution. Numerical results confirm that the proposed strategy is able to substantially reduce the blocking probability of high data rate requests at the cost of increased utilization of the packet switching layer and more complex routing of lightpaths.     

Flexible resource allocation strategies for class-based QoS provisioning in mobile networks

Flexible resource-allocation (FRA) strategies have been proposed in the literature to mitigate the high blocking rate caused in high-speed mobile communication networks when resource aggregation is used to increase the data rate. In this paper, new FRA strategies that cope with scenarios with multiple service types and multiple priorities are proposed. These are called the FRA strategy with differentiated priorities and quality of service (FRAQoS) and the FRA strategy with prioritized levels (FRASPL). The main distinguishing feature of these strategies is their capacity to prioritize some service types over others. FRAQoS prioritizes the quality of service (QoS) of particular service types over others by introducing the concepts of prioritized call degradation and compensation. However, FRAQoS provides a limited ability to prioritize particular service types over the rest because any incoming call, irrespective of its service type and priority, may trigger resource reallocations to service it. The FRASPL overcomes this limitation by introducing a call-admission mechanism that, when necessary, rejects calls originated by low-priority service types. This enhances the protection to high-priority service types. By prioritizing some services over the others, FRASPL can trade off capacity against QoS. FRAQoS represents particular limiting cases of FRASPL. A mathematical model is developed to investigate the performance of FRAQoS and FRASPL. Then, they are compared with other FRA strategies in a scenario with multiple differentiated service types. Results show that the proposed strategies effectively prioritize service types, providing them with better QoS. This makes FRAQoS and FRASPL specially suitable for class-based QoS provisioning in mobile networks.     

Joint resource allocation with QoS provisioning in K-tier heterogeneous cellular networks

In this paper, the joint resource allocation （RA） problem with quality of service （QoS） provisioning in downlink heterogeneous cellular networks （HCN） is studied. To fully exploit the network capacity, the HCN is modeled as a K-tier cellular network where each tier＇s base stations （BSs） have different properties. However, deploying numbers of low power nodes （LPNs） which share the same frequency band with macrocell generates severe inter-cell interference. Enhancement of system capacity is restricted for inter-cell interference. Therefore, a feasible RA scheme has to be developed to fully exploit the resource efficiency. Under the constraint of inter-cell interference, we formulate the RA problem as a mixed integer programming problem. To solve the optimization problem we develop a two-stage solution. An integer subchannel assignment algorithm and Lagrangian-based power allocation algorithm are designed. In addition, the biasing factor is also considered and the caused influence on system capacity is evaluated. Simulation results show that the proposed algorithms achieve a good tradeoff between network capacity and interference. Moreover, the average network efficiency is highly improved and the outage probability is also decreased.     

Satisfactory content delivery scheme for QoS provisioning in delay tolerant networks

We deal in this article with the content forwarding problem in delay tolerant networks (DTNs). We first formulate the content delivery interaction as a noncooperative satisfaction game. On one hand, the source node seeks to ensure a delivery probability above some given threshold. On the other hand, the relay nodes seek to maximize their own payoffs. The source node offers a reward (virtual coins) to the relay, which caches and forwards the file to the final destination. Each relay has to solve the dilemma of accepting/rejecting to cache the source's file. Cooperation incurs energy cost due to caching, carrying, and forwarding the source's file. Yet when a relay accepts to cooperate, it may receive some reward if it succeeds to be the first relay to forward the content to the destination. Otherwise, the relay may receive some penalty in the form of a constant regret; the latter parameter is introduced to make incentive for cooperation. Next, we introduce the concept of satisfaction equilibrium (SE) as a solution concept to the induced game. Now, the source node is solely interested in reaching a file delivery probability greater than some given threshold, while the relays behave rationally to maximize their respective payoffs. Full characterizations of the SEs for both pure and mixed strategies are derived. Furthermore, we propose two learning algorithms allowing the players (source/relays) to reach the SE strategies. Finally, extensive numerical investigations and some learning simulations are carried out to illustrate the behavior of the interacting nodes and to give some insightful thoughts on how to fine‐tune the network setting.     

The QoS provisioning tri-mode energy saving mechanism for EPON networks

The Ethernet passive optical network provides broadband Internet access but also consumes a lot of energy. Energy saving mechanisms using the dual-mode—Active and Sleep modes—design for optical network unit (ONU) in EPON still suffer unnecessary energy consumption, especially in asymmetric data flow such as video streaming downloading service. The Doze mode is particularly suitable for handling the asymmetric data flow since it allows the ONU’s transmitter to turn off while turning on its receiver to receive data from optical line termination (OLT). However, adding Doze mode into original dual-mode design incur a greater challenge for OLT to identify the current status of the ONU since the ONU cannot transmit any upstream message to OLT at either Doze or Sleep mode. In this paper, we propose a new QoS provisioning tri-mode energy saving scheme, by integrating the Doze mode into original dual-mode design, to allow the ONU to switch to one of the energy saving modes whenever no upstream traffic exists. A high-priority upstream packet, arriving at ONU of energy saving modes, is able to trigger the ONU back to Active mode for QoS provisioning purpose. Performance evaluation via simulation has demonstrated the effectiveness of such mechanism in various asymmetric data flow. Furthermore, we propose two additional enhanced approaches to increase the energy saving effects by deferring the triggering action of the high-priority upstream packet as well as coalescing new arrival packets during waiting time into the same scheduling cycle.     

Multiple QoS provisioning with pre-emptive priority schedulers in multi-resource OFDMA networks

Wireless Networks - In this paper, we present an analytical framework for the performance evaluation of a pre-emptive priority scheduler in multi-resource networks, like those using Orthogonal...     

Efficient resource provisioning using traffic balancing in multidomain optical networks

In multidomain optical networks (MDONs) the emerging multimedia, multivendor applications–based scheduled traffic (ST) is periodic and repeated day by day. The traffic is heavy during the working hours and slack during the non‐office hours. This results in the scarcity of network resources during the working hours, leading to the increased blocking of requests, even though there remains relatively large underused capacity during the non‐office hours. To use the network resources uniformly and efficiently, the demands may be slided within or shifted along the time zones/windows. In this paper, we first propose a heuristic algorithm, time‐aware routing and wavelength assignment (TA‐RWA), which allocates resources without traffic balancing (TB) for the ST in MDON. Time‐aware routing and wavelength assignment policy is then used as a benchmark for comparison with the 3 different TB solutions (named as P1‐TB, P2‐TB, and P3‐TB), in which the network load is redistributed by rescheduling the intradomain and interdomain demands. We performed extensive simulation experiments in MATLAB environment and compared the proposed policies with the existing ordering policies. From the results, it can be inferred that the proposed TB policies outperform the TA‐RWA, and the existing strategies of the blocking probability, resource utilization ratio (RUR), and percentage of intradomain and interdomain connections established. The best performance is achieved using P3‐TB strategy, in which requests are slided within, and shifted, along different time windows. The strategy shows about 70% reduction in the percentage blocking probability with respect to the TA‐RWA and the existing strategies.     

Service overlay networks: SLAs, QoS, and bandwidth provisioning

We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular, end-to-end quality of service (QoS), plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, Video-on-Demand, and other emerging QoS-sensitive services. The SON purchases bandwidth with certain QoS guarantees from the individual network domains via bilateral service level agreement (SLA) to build a logical end-to-end service delivery infrastructure on top of the existing data transport networks. Via a service contract, users directly pay the SON for using the value-added services provided by the SON. In this paper, we study the bandwidth provisioning problem for a SON which buys bandwidth from the underlying network domains to provide end-to-end value-added QoS sensitive services such as VoIP and Video-on-Demand. A key problem in the SON deployment is the problem of bandwidth provisioning, which is critical to cost recovery in deploying and operating the value-added services over the SON. The paper is devoted to the study of this problem. We formulate the bandwidth provisioning problem mathematically, taking various factors such as SLA, service QoS, traffic demand distributions, and bandwidth costs. Analytical models and approximate solutions are developed for both static and dynamic bandwidth provisioning. Numerical studies are also performed to illustrate the properties of the proposed solutions and demonstrate the effect of traffic demand distributions and bandwidth costs on SON bandwidth provisioning.     

Advanced QoS provisioning in IP networks: the European premium IP projects

This article describes the current evolution of QoS architectures, mechanisms, and protocols in the Internet, as it is ongoing in the framework of the European Union funded research projects on premium IP networks. A short review of the proposed standard approaches to QoS (e.g., differentiated services, integrated services, and label switching technologies) is given. Then we focus on the state-of-the-art architectures, mainly based on DiffServ concepts. Several issues arise when trying to implement these architectures in the real world: QoS aspects, network monitoring of the offered QoS, and end-user control of received QoS. The article then discusses the existing results and the current direction of European research and development in these areas.     

Performance enhancement of combining QoS provisioning and location management in wireless cellular networks

Quality-of-service (QoS) provisioning and location management (LM) in cellular networks are solved separately in previous work. For realistic network environments, we have proposed a framework of combining QoS provisioning and LM by using all available user mobility information. In this paper, we present performance evaluation to show that this framework can yield more efficient solutions for both. We propose a novel path-based LM scheme in this combined framework and evaluate the performance gain of the new scheme over the original path-based LM scheme by simulations. Further, we propose a new connection admission control (CAC) scheme derived from this combined framework for QoS provisioning and present results showing performance enhancements over CAC schemes proposed previously.     

Contention resolution and QoS provisioning using sparse fiber delay lines in WDM networks

In this paper, we combine fiber delay lines (FDL) and optical wavelength conversion (OWC) as the solution for the burst contention problem in optical burst switching (OBS). We present a placement algorithm, k-WDS, for the sparse placement of FDLs at a set of selected nodes in the network. The algorithm can handle both uniform and non-uniform traffic patterns. Our extensive performance tests show that k-WDS provides more efficient placement of optical fiber delay lines than the well-known approach of placing the resources at nodes with the highest experienced burst loss. Performance results are also given to compare the benefit of using FDLs alone, OWCs alone, as well as a mixture of both FDLs and OWCs. A new algorithm, A-WDS, for the placement of an arbitrary numbers of FDLs and OWCs is presented and evaluated under different uniform and non-uniform traffic loads using network simulation of the NSFNET topology and randomly generated graphs. The paper is concluded by presenting the design of a cost-effective optical switch equipped with variable-delay FDL bank. Based on the switch design, a scheme to provide differentiated services for multiple classes of traffic is presented and evaluated.     

A multi-path cognitive resource management mechanism for QoS provisioning in wireless mesh networks

In a Wireless Mesh Network (WMN), achieving acceptable Quality of Service (QoS) levels requires distributed control over network resources and subsequent awareness of the dynamically changing conditions of the WMN. In this paper, for facilitating such control, a cognitive mechanism is introduced, which facilitates cooperation and cognition among multiple Mesh Access Points and edge routers called Mesh Portals for routing client traffic via multiple paths. The aim of the cognition is to reasonably maximize the fulfillment of the clients from the achieved QoS (e.g., end-to-end delay and bandwidth). The cognitive process consists of three cycles. In the first cycle, the Perception Cycle, the current performance status of the WMN is continuously perceived through feedback loops. The perceived information is further processed and fed into the second cycle, the Learning Cycle, in order to understand the network conditions. This results in the prediction of the performance of the paths and estimation of the path delay for various load conditions. The third cycle, the Decision Cycle, is a game theoretic coalition formation algorithm, that results in path selection and data rate assignment. This algorithm is modeled as a cooperative game theory, which incorporates the Bilateral Shapley Value to find the best coalition from available paths, whereupon a bargaining game theory formulates the data rate assignment. Extensive simulations are performed for evaluating the proposed cognitive mechanism under various load conditions and results demonstrate the evident enhancement of the achieved end-to-end QoS of the clients and the network performance compared with non-cognitive scenarios, specifically in congested conditions.     

Analysis of a hybrid cutoff priority scheme for multiple classes of traffic in multimedia wireless networks

In this paper, we propose and analyze the performance of a new handoff scheme called hybrid cutoff priority scheme for wireless networks carrying multimedia traffic. The unique characteristics of this scheme include support for N classes of traffic, each may have different QoS requirements in terms of number of channels needed, holding time of the connection and cutoff priority. The proposed scheme can handle finite buffering for both new calls and handoffs. Futhermore, we take into consideration the departure of new calls due to caller impatience and the dropping of queued handoff calls due to unavailability of channels during the handoff period. The performance indices adopted in the evaluation using the Stochastic Petri Net (SPN) model include new call and handoff blocking probabilities, call forced termination probability, and channel utilization for each type of traffic. Impact on the performance measures by various system parameters such as queue length, traffic input and QoS of different traffic has also been studied. This revised version was published online in June 2006 with corrections to the Cover Date.