Performance of a priority-based dynamic capacity allocation scheme for wireless ATM systems (original) (raw)
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Dynamic reservation TDMA protocol for wireless ATM networks
IEEE Journal on Selected Areas in Communications, 2001
A dynamic reservation time division multiple access (DR-TDMA) control protocol that extends the capabilities of asynchronous transfer mode (ATM) networks over the wireless channel is proposed in this paper. DR-TDMA combines the advantages of distributed access and centralized control for transporting constant bit rate (CBR), variable bit rate (VBR), and available bit rate (ABR) traffic efficiently over a wireless channel. The contention slots access for reservation requests is governed by the framed pseudo-Bayesian priority (FPBP) Aloha protocol that provides different access priorities to the control packets in order to improve the quality-of-service (QoS) offered to time sensitive connections. DR-TDMA also features a novel integrated resource allocation algorithm that efficiently schedules terminals' reserved access to the wireless ATM channel by considering their requested bandwidth and QoS. Integration of CBR, voice, VBR, data, and control traffic over the wireless ATM channel using the proposed DR-TDMA protocol is considered in this paper. Simulation results are presented to show that the protocol respects the required QoS of each traffic category while providing a highly efficient utilization of approximately 96% for the wireless ATM channel.
Traffic scheduling in wireless ATM networks
IEEE ATM Workshop …, 1997
Wireless ATM is enjoying enormous research interest in the last few years, because of its ability to combine multimedia applications support, together with the freedom of mobility. One of the key design issues is the medium access control (MAC) protocol for the radio interface. This paper presents the traffic scheduling algorithm used in the MAC protocol of the Wireless ATM Network Demonstrator (WAND) system being developed within project Magic WAND. Magic WAND is investigating wireless ATM technology for customer premises networks in the framework of the Advanced Communications Technologies and Services (ACTS) programme, funded by the European Union. The proposed algorithm is delay oriented to meet the requirements of the various traffic classes defined by the ATM architecture. Simulation results are presented to assess the performance of the algorithm.
Queueing analysis of explicit priority assignment buffer access scheme for ATM networks
Computer Communications, 1998
The recommended implementation of two quality of service bearer services in ATM networks has generated considerable work on the analysis of implicit policy assignment space priority control buffer access schemes. Since then, there has been more interest directed towards explicit policy assignment space priority schemes because of their increased efficiency and flexibility over implicit assignment schemes. This paper considers an explicit policy assignment space priority control scheme employing the partial buffer sharing buffer access mechanism. Cell loss probabilities are derived for a traffic model consisting of two source classes. Each source class consists of bursty traffic generated by a multiple number of three-state discrete-time Markov sources. The dependence of cell loss probabilities on traffic load and burstiness characteristics, as well as system parameters such as buffer size and buffer sharing thresholds, is examined. ᭧ 1998 Elsevier Science B.V.
An integrated dynamic resource allocation scheme for ATM networks
IEEE INFOCOM '93 The Conference on Computer Communications, Proceedings, 1993
sharing an ATM link is considered as an integrated control problem with a multi-level structure. At the lower level, call admission control rules are applied that maintuin U certain grade of service, in terms of cell loss probability and cell delay, given the buffer space und bandwidth assigned to each class; unlike those used in previous works, these rules are derived on the basis of homogeneous (based on similar quantities) measures of the performance requirements. At the higher level, bandwrdth shares are periodically recomputed on-line by an allocation controller, whose goals reflect overall cell loss and refused trafSic, as well as overall average delay. These goals are expressed by an optimization problem that is solved by numerical techniques. The whole control system should provide a dynamic feedback controller, capable of reacting in real time to changes in the trafic patterns. Simulation results ure presented and discussed, regarding the eficiency of the admission controllers, the performance of the overall scheme, and the capability of reacting to sudden changes in the load of some truce cluss.
Improving traffic scheduling in wireless ATM networks
1998
The Medium Access Control (MAC) protocol and the underlying traffic scheduling mechanism for the radio interface are critical components of a wireless ATM network, aiming to provide ATM-like quality of service (QoS) guarantees over the air. A traffic scheduling algorithm for a wireless ATM customer premises network is proposed. The algorithm operates in the mobile terminals, and complements a centralized scheduling mechanism operating in the base stations, for improved performance. The proposed algorithm is delay oriented to meet the requirements of the various traffic classes defined by the ATM architecture. The system performance improvement attained by the proposed algorithm is evaluated via simulations.
A dynamic packet reservation multiple access scheme for wireless ATM
1999
The dynamic packet reservation multiple access (DPRMA) scheme, a medium access control protocol for wireless multimedia applications, is proposed and investigated. DPRMA allows the integration of multiple traffic types through a single access control mechanism that permits users to specify their immediate bandwidth requirements. The primary feature of DPRMA is the dynamic matching of the traffic source generation rates with the assigned portion of the channel capacity. This is accomplished by a control algorithm that regulates the actual amount of channel capacity assigned to users. To support multimedia communication, channel capacity assignments are prioritized by traffic type. The performance of the scheme is evaluated and the scheme is shown to perform well in a system with voice, video conferencing, and data users present. It is also shown to provide improved performance over a system with a modified version of the packet reservation multiple access (PRMA) scheme. Furthermore, several system parameters are studied and optimized.
2002
The MAC protocol, known as MASCARA (Mobile Access Scheme based on Contention And Reservation for ATM), is an infrastructure-based, adaptive TDMA scheme, which combines reservation-and contention-based access methods to provide multiple access efficiency and Quality-of-Service (QoS) guarantees to wireless ATM terminal connections that share a common radio channel. Radio channel sharing is performed by the PRADOS (Prioritized Regulated Allocation Delay Oriented Scheduling) algorithm. In this paper we assess the capability of PRADOS to guarantee to voice and data traffic types the QoS they need. The analysis leads to the conclusion that PRADOS cannot avoid the interference between the various types of traffic. A criterion to alleviate this drawback is also outlined at the end of the paper.
Resource allocation for worst case traffic in ATM networks
Performance Evaluation, 1997
This paper addresses the problem of resource allocation for ATM connections carrying either CBR or VBR applications, for the first generation of ATM equipments. Evaluating the resources needed for the transfer phase of an ATM connection is a first step in the design of a CAC taking into account both call and transfer level QoS. The required amount of resources is estimated on the basis of traffic characteristics negotiated at call set-up, under the assumption that the offered traffic is a purely periodic pattern of active and inactive periods; this assumption is currently considered to yield upper bounds for the amount of resources which must be allocated to a connection. The traffic characteristics, and the corresponding periodic patterns of traffic are obtained using the ITU-T specification of ATM traffic control. We identify three frameworks (allocation on the basis of PCR, burst loss and burst delay framework in case of statistical multiplexing) and principles on which resource allocation can be based in each of these frameworks are highlighted.
Computer Communications, 1997
The cell loss probability and the mean cell delay are major performance metrics in analyzing a statistical multiplexer loaded with a superposition of independent and heterogeneous bursty sources. In this paper, we model each arrival process by a two-state discrete-time Markovian arrival process (D-MAP). We discuss that this traffic modeling is more realistic than the other ones in ATM networks. Then we model the superposition of r types of the two-state D-MAPS into a discrete-time batch Markovian arrival process (D-BMAP) with 2' states. By using the steady-state analysis of the D-BMAPIDIlIKqueueing model, we obtain the exact cell loss probabilities and the mean cell delays for each type of traffic in the statistical multiplexer. In particular, we derive the formulas concerned with these performance metrics under two buffer access strategies of the simultaneous cell arrivals at the same slot: (1) fair access, and (2) priority access. From some numerical examples, we show that the performance of each traffic at the statistical multiplexer may be severely affected by its own traffic characteristics and priority of buffer access, as well as the traffic characteristics of the others. 0 1997 Elsevier Science B.V.