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1.
We propose and analyze call admission control algorithms integrated with pricing for revenue optimization with QoS guarantees to serve multiple service classes in mobile wireless networks. Traditional admission control algorithms make acceptance decisions for new and handoff calls to satisfy certain QoS constraints such as the dropping probability of handoff calls and the blocking probability of new calls being lower than a pre-specified threshold. We analyze a class of partitioning and threshold-based admission control algorithms that make acceptance/rejection decisions not only to satisfy QoS requirements but also to optimize the revenue of the system by taking prices and arrival/departure information of service calls into account. We show that for a “charge-by-time” pricing scheme, there exist optimal resource allocation settings under which the partitioning and threshold-based admission control algorithms would produce the maximum revenue obtainable by the system without sacrificing QoS requirements. Further, we develop a new hybrid admission control algorithm which outperforms both partitioning and threshold-based admission control algorithms over a wide range of input parameters characterizing the operating environment and service workload conditions. Methods for utilizing of the analysis results for realtime admission control for revenue optimization with QoS guarantees are described with numerical data given to demonstrate the applicability.  相似文献   
2.
How to efficiently support multi-class services is a very important issue in integrated wireless and mobile networks because each type of services has distinct characteristics and quality of service (QoS) requirements. This paper presents an efficient algorithm for near optimal channel allocation when different types of services are to be provided in the next generation integrated wireless and mobile networks. We specifically propose a preemptive priority scheme for an integrated wireless and mobile network by first dividing channels into three independent groups and classifying traffic into four different types. The proposed system is modeled by a multi-dimension Markov chain model. Then such a model is used to obtain a set of relations that correlate performances with various system parameters. A novel recursive algorithm is developed to determine the minimal number of channels in each channel group that would be necessary to satisfy the QoS requirements. We also investigate the impact of load ratio for different types of traffic on channel assignment. Finally, we discuss some limitations of our approach and indicate possible future work. We believe that the partitioning scheme proposed in this paper can become a starting point for analysis of future integrated wireless and mobile networks.  相似文献   
3.
An Improved Round Robin Packet Scheduler for Wireless Networks   总被引:1,自引:0,他引:1  
Scheduling algorithms are important components for providing quality-of-service (QoS) guarantees in wireless networks. The design of such algorithms need to take into account bursty errors and location-dependent channel capacity that are characteristics of wireless networks. In this paper, a new scheduling algorithm for packet cellular networks, wireless deficit round robin (WDRR), is proposed. WDRR is a round robin scheduler that has low implementation complexity and offers a low delay bound, tight fairness index, and good isolation property. In error-prone channels, the algorithm provides short-term fairness among sessions that perceive a clean channel, long-term fairness among all sessions, ability to meet specified throughput objectives for all sessions, and graceful service degradation among sessions that received excess service. Both analysis and simulation are used to verify the WDRR properties.  相似文献   
4.
Utilization-Based Admission Control for Scalable Real-Time Communication   总被引:3,自引:0,他引:3  
We propose a utilization-based schedulability and admission control mechanism for distributed systems with workload aggregation to achieve scalability. We use the differentiated services (diffserv) architecture to describe and illustrate our approach. Scalability of admission control is achieved by determining off-line safe levels of server utilization. Scalability during the connection lifetimes is provided by the aggregation mechanisms (for example, class-based scheduling) provided by the diffserv architecture. Our evaluations show that our system's admission probabilities are very close to those of significantly more expensive approaches, which do not allow for workload aggregation. At the same time, admission control overhead during flow establishment is very low.  相似文献   
5.
We consider a time-slotted W-CDMA system for mobile stations which are connected to the wired internet. We first present an architecture for such a system that is based on a request-permission protocol incorporating power control for Best Effort transmissions on the uplink. The requesting mobiles are permitted to transmit in the next time slot with a specified power according to a schedule computed by the Base Station. To devise this scheduling method, we formulate a globally optimizing integer program that maximizes the total weighted sum of all best-effort transmissions in the entire system, keeping in view the diverse target Bit Error Rates for each one. This problem is analysed and decomposed into sub-problems that can be solved locally by each Base Station. We devise two fast heuristics to solve the Base Station's sub-problem, so that the new schedule for each successive slot can be re-computed by each Base Station in a practical time-frame. We show that one heuristic is good enough to produce optimal solutions to the sub-problem in special cases. The method is further enhanced to take account of bandwidth and delay guarantees for other connections. It is also modified to ensure fairness for best-effort code channels suffering from persistent location-dependent errors. Finally, we show that a very similar approach can be used by the Base Station for scheduling on the downlink also, leading to a unified approach to scheduling in both directions. The efficacy of the uplink method is briefly demonstrated by simulations comparing the two variants with each other, and demonstrating that one achieves a consistently higher throughput than the other.  相似文献   
6.
Many modern multimedia applications require the retrieval of different classes of data with drastically different characteristics. For instance, digital libraries type systems must be designed to deliver not only text files and still images, but voice and video as well. These applications can benefit from the sharing of resources such as disk and network bandwidth, instead of the conservative approach of partitioning the resources according to the characteristics of each type of data being retrieved. Continuous and non-continuous media applications, require different performance metrics to be achieved, so that the necessary quality of service (QoS) is satisfied. As a consequence, the proper managing of resources is a major issue in order to provide the complete sharing of resources and yet reaching the QoS goals. This work focuses on multimedia storage systems that are capable of serving a mixture of continuous and non-continuous workloads. Our main objective is to expose and investigate the tradeoffs involved in managing the system resources, in particular, I/O bandwidth. The performance metrics of interest are the mean and variance of response time for non-continuous media requests and the probability of missing an imposed deadline for continuous media workloads. Different scheduling algorithms are considered and tradeoffs to achieve performance goals are studied, including those involving buffer sizing.  相似文献   
7.
Routing algorithms play a critical role in meeting both the stringent quality of service (QoS) requirements of guaranteed services and the certain QoS requirement of assured services over next-generation multiservice high-speed networks. In this paper, we propose the use of optimal least weight routing (OLWR) algorithm for routing QoS flows in high-speed networks. The main principle of our algorithm is that the choice of the most appropriate route is based on a set of parameters (least weight parameters) that estimate and consider the impact that the acceptance and routing decision of a call request belonging to a specific class would have on the network and other classes of service. Effective bandwidth, bandwidth and trunk reservation techniques, along with load balancing and packing trade-off considerations, are also introduced in the proposed routing algorithm. The performance evaluation of our algorithm is achieved via modeling and simulation of multiclass service routing in various network topologies. The performance results demonstrated that OLWR outperforms both the multihop least-loaded routing algorithms and the multihop most-loaded routing algorithms in terms of both revenue and carried load.  相似文献   
8.
MPLS网络中保证服务质量的多径路由选择策略   总被引:4,自引:0,他引:4       下载免费PDF全文
牛志升  段翔  刘进 《电子学报》2001,29(12):1638-1641
 本文提出了一种在多协议标签交换(MPLS, Multiple Protocol Label Switching) 网络中保证服务质量 (QoS,Quality-of-Service) 的多径路由选择策略,其核心思想是引入多路径分散业务量机制,在保证用户服务质量要求的同时达到增加网络呼叫接受率和平衡网络负载的目的.文中着重讨论了用户端对端服务质量要求的多路分解和分配问题,在此基础上提出了多径路由的分支路径选择策略,并研究了策略中的关键参数K对该策略性能的影响.数值结果显示出多路径分散业务量在网络负载均衡方面的重要意义,并且表明用户的要求相对网络资源越高使用多径传输的优势越明显.  相似文献   
9.
In general, the users of wireless ATM terminalsrequest the same functionality and quality of service asusers of wired terminals. These user requirements can betransformed into the demand for building an ATM multiplexer around the air interfacewhich is characterized by a radio channel inside. Themain difference between this virtual ATM multiplexeraround the air interface and a fixed ATM multiplexer is the distribution of the multiplexingfunction between wireless terminals and the basestation. For the uplink this requires a frequentnotification of the ATM cell scheduler in the basestation about the status of the incoming buffers inside thewireless terminals. This paper focuses on differentmethods for transmitting capacity request messages (alsodesignated as reservation request) over theuplink.  相似文献   
10.
The paper deals with error control proceduresbased on repetitions necessary for an ATM air interface,which enables a full integration of wireless (W) ATMterminals into a fixed ATM network. The architecture and functionality of an additional LLC layer atthe air interface are explained. A set of ARQ protocolsfor the different ATM service classes is investigated.The protocol for VBR services is able to control the number of retransmissions depending on therequirements on maximum delay and residual cell lossratio. It also takes into account instantaneousconditions such as channel load from other sources.Furthermore, the protocol is able to discard ATM cells toavoid and resolve congestion. The performance of theprotocol has been evaluated by simulations.  相似文献   
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