We propose a coordinated resource allocation (CRA) scheme that can be used to allocate high data-rate users in sectorized cells. This scheme is useful for allocating high data-rate users at cell boundaries. In order to analyze the performance of the proposed scheme, we make an interference model for a sectorized CDMA system and suggest the system load measurement of the forward link. Based on this system load measurement, data throughput for the CDMA system under perfect and imperfect power control is then analyzed. Numerical results show that throughput is significantly increased when the CRA scheme is used.

A Fair Queueing Algorithm is proposed for data services in an integrated voice/data CDMA system. We introduce short-term and long-term fairness concepts to allocate data users fairly. Using these concepts, we propose a Weighted Fair Queueing with Status Control (WFQS) in the consideration of a Generalized Processor Sharing (GPS) fluid-flow model. This proposed scheme allocates resources using channel status information. The throughput and delay of data users could be improved when this scheme is applied to wireless channels.

The proposed medium access protocol deals especially with the timely-transmission of real-time packets in wireless multimedia networks where users of many types of traffic are present. It works based on Time Division Multiple Access/Time Division Duplex (TDMA/TDD) technique and fixed-length packet switching incorporating two different policies to work differently on either non-congestion or congestion periods. In the policy to deal with congestion periods the concept of urgent packet has been introduced as any packet whose transmission deadline is on the next frame. Hence, during periods of congestion users inform to the Base Station the number and average deadline of the urgent packets in their buffers through requirement messages. According to that information the system is able to distribute its resources in a more efficient way during periods of congestion making the real-time packet loss rate decrease considerably. The simulation results show a very good performance of the method in networks where different types of traffic coexist even under high traffic-load conditions. The results also show a good trade-off characteristic between the real-time access delay and the buffer occupancy of non-real time terminals during congestion periods.

A great deal of effort has been spent to develop strategies for allocation of resources in DS-CDMA systems in order to mitigate effects of interference between users. Here, the choice of spreading sequences and appropriate power allocation play a crucial role. When developing such strategies, CDMA system designers need to ensure that each user meets its quality-of-service requirement expressed in terms of the signal-to-interference+noise ratio. We say that a set of users is admissible in a CDMA system if one can assign sequences to the users and control their power so that all users meet their quality-of-service requirements. In [1], the problem of admissibility in a synchronous CDMA channel was solved. However, since the simplistic setting of perfect symbol synchronism rarely holds in practice, there is a strong need for investigating asynchronous CDMA channels. In this paper, we consider a K-user asynchronous CDMA channel with processing gain N and identical performance requirements for all users assuming chip synchronism. We solve the problem of admissibility of the users in such a channel if N K, and identify optimal sequences. We also show that constant power allocation is optimal. Results obtained in this paper give valuable insights into the limits of asynchronous CDMA systems.

In this paper, we propose an efficient quality-providing scheme to satisfy delay bound and loss ratio requirements for real-time video applications. To utilize network resources more efficiently while meeting service requirements, the network resources are dynamically allocated to each video connection based on the predicted traffic and currently provided quality of service degree. With the proposed bandwidth allocation method, a fair quality of service support in terms of packet loss ratio and maximum packet transfer delay to each video source can be achieved. To avoid possible quality violation by incoming new video connections, we present a connection admission control based on the provided QoS for existing connections and the measured traffic statistics. Simulation results show that our proposed dynamic method is able to provide accurate quality control.

Sophisticated and robust resource management is an essential issue in future wireless systems which will provide a variety of application services. In this paper, we employ an adaptive-network-based fuzzy inference system (ANFIS) to control the resource allocation for mobile multimedia networks. ANFIS, possessing the advantages of expert knowledge of fuzzy logic system and learning capability of neural networks, can provide a systematic approach to finding appropriate parameters for the Sugeno fuzzy model. The fuzzy resource allocation controller (FRAC) is designed in a two-layer architecture and selects properly the capacity requirement of new call request, the capacity reservation for future handoffs, and the air interface performance as input linguistic variables. Therefore, the statistical multiplexing gain of mobile multimedia networks can be maximized in the FRAC. Simulation results indicate that the proposed FRAC can keep the handoff call blocking rate low without jeopardizing the new call blocking rate. Also, the FRAC can indeed guarantee quality of service (QoS) contracts and achieve higher system performance according to network dynamics, compared with the guard channel scheme and ExpectedMax strategy.

The capacity analysis of CDMA forward link is required to allocate high data-rate users. To solve this problem, we analyze the capacity of the CDMA forward link based on optimum power control. In a multi-cell environment, the intracell interference and intercell interference are derived. To show the capacity impact of high data-rate users, we introduce a location dependent factor, which is the ratio of intercell interference to intracell interference. Considering the location dependent factor, we propose a coordinated allocation scheme that can be used to allocate high data-rate users in sectorized cells. As a result, we show the capacity impact of high data-rate users according to location variations. The outage probability can be decreased when the coordinated allocation scheme is applied.

This paper proposes an area/time optimizing algorithm in a high-level synthesis system for control-based hardwares. Given a call graph whose node corresponds to a control flow of an application program, the algorithm generates a set of state-transition graphs which represents the input call graph under area and timing constraint. In the algorithm, first state-transition graphs which satisfy only timing constraint are generated and second they are transformed so that they can satisfy area constraint. Since the algorithm is directly applied to control-flow graphs, it can deal with control flows such as bit-wise processes and conditional branches. Further, the algorithm synthesizes more than one hardware architecture candidates from a single call graph for an application program. Designers of an application program can select several good hardware architectures among candidates depending on multiple design criteria. Experimental results for several control-based hardwares demonstrate effectiveness and efficiency of the algorithm.

This paper proposes radio resource control scheme for ABR service that execute flow-control on the transmission rate and assignable bandwidth according to the congestion conditions in both wireless and wired networks. The proposed scheme is useful in improving frequency utilization and meeting the QoS requirements. There are two methods to realize the proposed scheme: explicit rate control (ERC) and binary control (BC). We estimate the performance of the proposed scheme by simulation in comparison with a scheme without flow control in a wireless network under the conditions of a finite buffer, wired network congestion, and RM-cell errors. Consequently, we confirm that the proposed scheme is more effective than the scheme without flow-control under all service conditions. In addition, we clarify that both ERC and BC are effective under the conditions of a finite buffer, wired network congestion, and RM-cell errors.

This paper proposes a new distributed connection establishment scheme involving several competing network providers in a multimedia telecommunications environment. This connection establishment scheme, which is based on the concept of open competitive bidding, enables mutual selection by users and network providers. By employing this proposed scheme, both network providers and users can pursue their own objectives, according to their own bidding and awarding strategies. In this paper, a simple bidding strategy for network providers is presented, and the effectiveness of this strategy is evaluated by means of computer simulation. It is shown that each network provider can improve its profit by adopting this strategy. In this paper, an example of utility functions for users is presented, and the effectiveness of the mechanism with which users can select a network provider is also evaluated by means of computer simulation. Each user can improve his/her utility by selecting an appropriate network provider based on this utility function.

This paper discusses the generalized mutual exclusion problem defined by H. Kakugawa and M. Yamashita. A set of processes shares a set of resources of an identical type. Each resource must be accessed by at most one process at any time. Each process may have different accessible resources. If two processes have no common accessible resource, it is reasonable to ensure a condition in resource allocation, which is called allocation independence in this paper, i. e. , resource allocation to those processes must be performed without any interference. In this paper, we define a new structure, sharing structure coterie. By using a sharing structure coterie, the resource allocation algorithm proposed by H. Kakugawa and M. Yamashita ensures the above condition. We show a necessary and sufficient condition of the existence of a sharing structure coterie. The decision of the existence of a sharing structure coterie for an arbitrary distributed system is NP-complete. Furthermore, we show a resource allocation algorithm which guarantees the above requirement for distributed systems whose sharing structure coteries do not exist or are difficult to obtain.

We study resource allocation strategies in ATM switches, which provide quality of service (QoS) guarantees to individual connections. In order to minimize the cell loss rate over a wide range of traffic characteristics, an efficient allocation strategy is necessary. In this paper we introduce a resource allocation strategy, named TP+WRR (Threshold Pushout + Weighted Round Robin) which can fully utilize the buffer space and the bandwidth. We compare the performance of TP+WRR with two typical resource allocation strategies. An exact queueing analysis based on a Markov model is carried out under bursty traffic sources to evaluate their performance. Our results reveal that TP+WRR considerably improves the cell loss probability over the other strategies considered in this paper, especially when many connections are sharing a link.

In GSM High Speed Circuit Switched Data (HSCSD), the data rate can be increased by using multiple time slots instead of single time slot. Multiple time-slot assignment results in high blocking rate. To accommodate more users, flexible resource allocation strategies have been proposed. Since GSM follows TDMA/FDMA, the channels (time slots) in a base station are segmented by frequency carriers. The base station must allocate the channels which belong to the same frequency carrier to individual requests. This Flexible Resource Allocation scheme for GSM (FRA-GSM) is contrastive to the scheme proposed in our previous studies where a base station may arbitrarily allocate idle channels in the base station to incoming requests. We define satisfaction indication SI as the measurement to compare the performance of these schemes. Experiment results indicate that FRA-GSM scheme has good performance when the user mobility is high, or when some cost factors are taken into account.

One of the important challenges in the design of ATM networks is how to provide quality-of-service (QoS) while maintaining high network resource utilization. In this paper, we discuss the role of real-time traffic characterization in QoS control for ATM networks and review several approaches to the problem of resource allocation. We then describe a particular framework for QoS control in which real-time measurements of a connection stream are used to determine appropriate parameters for usage parameter control (UPC). Connection admission control (CAC) is based on the characterization of the aggregate stream in terms of the individual stream UPC descriptors, together with real-time measurements.

This paper presents severl radio resource scheduling algorithms which aim to provide best-effort service for non-real-time unit-oriented, or message traffic. The objective of resource scheduling algorithm is to distribute radio resources between competing message traffic sources while attaining throughput as high and fair as possible for each source without any explicit quality-of-service (QoS) guarantee. Computer simulations are carried out to evaluate the performance in terms of the average of allocation plus transfer delay, the average of throughput, the variance of throughput, and the usage of resources. The message-size distributions of homepages in World-Wide-Web and e-mails obtained by actual measurement are used. Message size-based resource scheduling algorithms are found to provide high and fair throughput as well as efficient use of the resources.

In this paper, algorithms for resource allocation in an ATM node that serves heterogeneous traffic sources subject to varying Quality of Service (QoS) requirements are proposed. The node can be either a switch port or a multiplexer. Each connection is first individually treated as logical queue. Quick and efficient algorithms allocating service rate and buffer space to each connection based on traffic characteristics and QoS requirement are developed. In order to improve link and buffer utilization, the aggregate traffic is next replaced by an appropriately parameterized new traffic source that still preserves the key characteristics of the aggregate traffic. The most stringest QoS requirement among all connections is selected to be the QoS target of the new traffic source to assure that QoS of each individual connection is satisfied. Resource allocation for the aggregate traffic is determined based on the traffic parameters and QoS target of the new source. Each individually determined service rate and buffer space can be used in cell transmission scheduling and selective cell discarding. In other words, resource allocation together with two related side problems: cell transmission and cell discarding, are treated in this paper in an integrated and efficient manner. The resource allocation algorithms proposed in this paper can also be used to support Call Admission Control (CAC) in ATM networks.

A new GSM data protocol called high speed circuit switched data (HSCSD) have been developed by European Telecommunications Standards Institute (ETSI) for high speed file transfer and mobile video applications. HSCSD increases data rate by using multiple TDMA time slots (up to 8) instead of one time slot in the current GSM implementation. The problem of multiple time slot assignment is that blocking rate of the system will increase. This problem can be solved by flexible resource assignment where the service specifies the maximum and the minimum capacity. Based on the current available capacity of a base station, a user will be assigned any rate between the maximum and the minimum capacities. This article describes HSCSD protocol and presents four radio resource allocation strategies for HSCSD: always allocates maximum, always allocates minimum, allocates maximum unless available resources are not enough, and allocates resources according to the current blocking statistics of the base station. A simulation model is proposed to investigate the performance of these algorithms. The blocking probability, the call completion probability, and the quality of service are used to evaluate the effects of algorithms in different system behaviors.

We propose a high-level synthesis method that uses data path information given by a designer. The main purpose of this method is to generate a control unit, one of the most difficult aspects of hardware design. In general, designers can specify data paths easily. Therefore, we believe that basing a method on specified data path information is the best way to synthesize hardware that more closely satisfies the designer's requirements. Moreover, a datapath-constrained scheduling algorithm can perform both "scheduling" and "resource allocation" at the same time. In particular, the resource allocation explicitly decides used paths as well as functional modules in each execution state. This cannot be done with previously reported algorithms.