Survey of traffic control schemes and error control schemes for ATM networks

Among the techniques proposed for B-ISDN transfer mode, ATM concept is considered to be the most promising transfer technique because of its flexibility and efficiency. This paper surveys and reviews a number of topics related to ATM networks. Those topics cover congestion control, provision of multiple classes of traffic, and error control. Due to the nature of ATM networks, those issues are far more challenging than in conventional networks. Sorne of the more promising solutions to those issues are surveyed, and the corresponding results on performance are summarized. Future research problems in ATM protocol aspect are also presented

Performance analysis of error recovery and congestion control in high-speed networks

In the past few years, Broadband Integrated Services Digital Network (B-ISDN) has received increasing attention as a communication architecture capable of supporting multimedia applications. Among the techniques proposed to implement B-ISDN, Asynchronous Transfer Mode (ATM) is considered to be the most promising transfer technique because of its efficiency and flexibility.In ATM networks, the performance bottleneck of the network, which was once the channel transmission speed, is shifted to the processing speed at the network switching nodes and the propagation delay of the channel. This shift is because the high-speed channel increases the ratio of processing time to packet transmission time and also the ratio of propagation delay to packet transmission time. The increased processing overhead makes it difficult to implement hop-by-hop schemes, which may impose prohibitably high processing at each switching node. The increased propagation delay overhead makes traffic control in ATM a challenge since a large number of packets can be in transit between two ATM switching nodes. Because of these fundamental changes, control schemes developed for traditional networks may not perform efficiently, and thus, new network architectures (congestion control schemes, error control schemes, etc.) are required in ATM networks.In this dissertation, we first present an extensive survey of various traffic control schemes and network protocols for ATM networks. In this survey, possible traffic control schemes are examined, and problems of those schemes and their possible solutions are presented. Next, we investigate two key research issues in ATM networks (and other types of high-speed networks): the effects of protocol-processing overhead and the efficiency of traffic control schemes.We first investigate the effects of protocol-processing overhead on the performance of error recovery schemes. Specifically, we investigate the performance trade-offs between link-by-link and edge-to-edge error recovery schemes. Our results show that for a network with high-speed/low-error-rate channels, an edge-to-edge scheme gives a smaller delay than a link-by-link scheme. We then investigate the effectiveness of a priority packet discarding scheme, a congestion control mechanism suitable for high-speed networks. We derive loss probabilities for each stream and investigate the impact of burstiness of traffic streams on the performance of individual streams

Buffer management and cell switching management in wireless packet communications

The buffer management and the cell switching (e.g., packet handoff) management using buffer management scheme are studied in Wireless Packet Communications. First, a throughput improvement method for multi-class services is proposed in Wireless Packet System. Efficient traffic management schemes should be developed to provide seamless access to the wireless network. Specially, it is proposed to regulate the buffer by the Selective- Delay Push-In (SDPI) scheme, which is applicable to scheduling delay-tolerant non-real time traffic and delay-sensitive real time traffic. Simulation results show that the performance observed by real time traffics are improved as compared to existing buffer priority scheme in term of packet loss probability. Second, the performance of the proposed SDPI scheme is analyzed in a single CBR server. The arrival process is derived from the superposition of two types of traffics, each in turn results from the superposition of homogeneous ON-OFF sources that can be approximated by means of a two-state Markov Modulated Poisson Process (MMPP). The buffer mechanism enables the ATM layer to adapt the quality of the cell transfer to the QoS requirements and to improve the utilization of network resources. This is achieved by selective-delaying and pushing-in cells according to the class they belong to. Analytical expressions for various performance parameters and numerical results are obtained. Simulation results in term of cell loss probability conform with our numerical analysis. Finally, a novel cell-switching scheme based on TDMA protocol is proposed to support QoS guarantee for the downlink. The new packets and handoff packets for each type of traffic are defined and a new cutoff prioritization scheme is devised at the buffer of the base station. A procedure to find the optimal thresholds satisfying the QoS requirements is presented. Using the ON-OFF approximation for aggregate traffic, the packet loss probability and the average packet delay are computed. The performance of the proposed scheme is evaluated by simulation and numerical analysis in terms of packet loss probability and average packet delay

Survey of congestion control techniques for an ATM network

The emerging broadband integrated services digital network is expected to adopt ATM (Asynchronous Transfer Mode) as the transport network. This new network must support several classes of service with varying delay and loss requirements. It must also operate with link speeds in the hundreds of megabits per second and be scalable up to potential link speeds on the order of gigabits per second. The requirements to support multiple services and high speed make the congestion control in an ATM network difficult. This paper reviews sorne of the techniques for prevention and control of congestion in an ATM network

Protocol-processing overhead on the performance of error recovery schemes in high-speed network environments

This paper investigates the effects of protocol-processing overhead on the performance of error recovery schemes in high-speed network environments. The investigated error recovery schemes are:• an edge-to-edge error recovery scheme, where retransmissions of erred packets only take place between source and destination nodes, and• a link-by-link error recovery scheme, where retransmissions only take place between adjacent switching nodes.For retransmission of erred packets, we consider both Go-Back-N and Selective-Repeat procedures in the analysis.The performance measures we obtain are the distribution of transfer delays and the loss probability of packets across a network. To obtain these measures, this paper develops a tandem queueing network model with feedbacks where each queue represents a protocol layer within a switching node, rather than a switching node as a whole.Numerical results show that for a network with very-high-speed/low-error-rate channels, an edge-to-edge scheme gives the smaller packet transmission delay than a link-by-link scheme for both Go-back-N and Selective-Repeat retransmission procedures, while keeping the packet loss probability sufficiently small

Traffic control mechanisms with cell rate simulation for ATM networks.

PhDAbstract not availabl

Priority Control in ATM Network for Multimedia Services

The communication network of the near future is going to be based on Asynchronous Transfer Mode (ATM) which has widely been accepted by equipment vendors and service providers. Statistical multiplexing technique, high transmission speed and multimedia services render traditional approaches to network protocol and control ineffective. The ATM technology is tailored to support data, voice and video traffic using a common 53 byte fixed length cell based format with connection oriented routing. Traffic sources in A TM network such as coded video and bulk data transfer are bursty. These sources generate cells at a near-peak rate during their active period and generate few cells during relatively long inactive period. Severe network congestion might occur as a consequence of this dynamic nature of bursty traffic. Even though Call Admission Control (CAC) is appropriately carried out for deciding acceptance of a new call, Quality of Service (QOS) may be beyond the requirement limits as bursty traffic are piled up. So, priority control, in which traffic stream are classified into several classes according to their QOS requirements and transferred according to their priorities, becomes an important research issue in ATM network. There are basically two kinds of priority management schemes: time priority scheme that gives higher priority to services requiring short delay time and the space priority scheme that gives high priority cells requiring small cell loss ratio. The possible drawbacks of these time and space priority schemes are the processing overhead required for monitoring cells for priority change, especially in the case of time priority schemes. Also, each arriving cell needs to be time stamped. The drawback of the space priority scheme lies in the fact that buffer management complexity increases when the buffer size becomes large because cell sequence preservation requires a more complicated buffer management logic. In this thesis, a Mixed Priority Queueing or MPQ scheme is proposed which includes three distinct strategies for priority control method -- buffer partitioning, allocation of cells into the buffer and service discipline. The MPQ scheme is, by nature, a non-fixed priority method in which delay times and loss probabilities of each service class are taken into account and both delay times and loss probabilities can be controlled with less dependency compared with the fixed priority method, where priority grant rule is fixed according to the service class, and the priority is always given to the highest class cell among cells existing in the buffer. The proposed priority control is executed independently at each switching node as a local buffer management. Buffer partitioning is applied to overcome the weakness of the single buffer