Teletraffic Science and Engineering 

About: Teletraffic Science and Engineering is an academic journal. The journal publishes majorly in the area(s): Network packet & Quality of service. It has an ISSN identifier of 1388-3437. Over the lifetime, 408 publications have been published receiving 5238 citations.

Scheduling algorithms for a mixture of real-time and non-real-time data in HDR

Abstract: High Data Rate (HDR) technology has recently been proposed as an overlay to CDMA as a means of providing packet data service to mobile users. In this paper, we study various scheduling algorithms for a mixture of real-time and non-real-time data over HDR/CDMA and compare their performance. We study the performance with respect to packet delays and also average throughput, where we use a token based mechanism to give minimum throughput guarantees. We find that a rule which we call the exponential rule performs well with regard to both these criteria. (In a companion paper, we show that this rule is throughput-optimal, i.e., it makes the queues stable if it is feasible to do so with any other scheduling rule). Our main conclusion is that intelligent scheduling algorithms in conjunction with token based rate control provide an efficient framework for supporting a mixture of real-time and non-real-time data applications in a single carrier.

On burst assembly in optical burst switching networks—A performance evaluation of just-enough-time

Abstract: On the way towards an architecture for a new QoS-supporting and scalable Internet, the IP-over-photonics approach seems to be very promising. One possible solution in this domain is optical burst switching (OBS), a concept combining advantages of optical circuit and packet switching. After an introduction to OBS as well as the reservation mechanism Just-Enough-Time (JET) we present an approximative analysis of the burst loss probability in an OBS node for an arbitrary number of service classes. Based on analytical and simulation results, we show the impact of traffic characteristics on service differentiation in a single node. Finally, we investigate service differentiation for various parameters in an OBS network scenario.

IGP link weight assignment for transient link failures

Abstract: Intra-domain routing in IP backbone networks relies on link-state protocols such as IS-IS or OSPF. These protocols associate a weight (or cost) with each network link, and compute traffic routes based on these weight. However, proposed methods for selecting link weights largely ignore the issue of failures which arise as part of everyday network operations (maintenance, accidental, etc.). Changing link weights during a short-lived failure is impractical. However such failures are frequent enough to impact network performance. We propose a Tabu-search heuristic for choosing link weights which allow a network to function almost optimally during short link failures. The heuristic takes into account possible link failure scearios when choosing weights, thereby mitigating the effect of such failures. We find that the weights chosen by the heuristic can reduce link overload during transient link failures by as much as 40% at the cost of a small performance degradation in the absence of failures (10%).

Class and channel condition based weighted proportional fair scheduler

Abstract: In this paper we outline a scheme to perform packet-level scheduling and resource allocation at the wireless node that takes into account the notions of both efficiency and fairness and presents a means to explore the trade-off between these two notions. As a part of this scheme we see the scheduling problem as deciding not just the packet transmission schedule but also the power allocation, the modulation and coding scheme allocation and the spreading code determination since the latter three directly influence the radio resources consumed. Using a utility maximization formulation based on the data-rates that the mobiles can transmit at, we decide on the weights for a weighted proportionally fair allocation based scheduling algorithm. We conclude with a simulation based performance analysis for infinitely-backlogged sources on a UMTS system.