Roland de Haan - Academia.edu (original) (raw)
Papers by Roland de Haan
Annals of Operations Research, Jan 27, 2011
Advances in Applied Probability, Mar 1, 2020
Memorandum (institute of Pacific Relations, American Council), Dec 1, 2007
Processor sharing (PS) models nicely capture the bandwidth sharing and statistical multiplexing e... more Processor sharing (PS) models nicely capture the bandwidth sharing and statistical multiplexing effect of TCP at the flow-level. However, these 'rough' models do not provide insight into the impact of packet-level parameters (round trip time, buffer size) on performance metrics such as throughput and flow transfer times. In a previous paper an analytical, integrated packet/flow model was developed, exploiting the advantages of PS approach at the flow-level, while incorporating the most significant packet-level effects. In the present paper we propose an enhancement of this model, which is validated through extensive NS simulations. The numerical results show that this enhancement leads to significantly better performance approximations than the originally proposed model.
Probability in the Engineering and Informational Sciences, Mar 19, 2014
In this paper, we will develop a tool to analyze polling systems with the autonomous-server, the ... more In this paper, we will develop a tool to analyze polling systems with the autonomous-server, the time-limited, and the k-limited service discipline. It is known that these disciplines do not satisfy the well-known branching property in polling system, therefore, hardly any exact result exists in the literature for them. Our strategy is to apply an iterative scheme that is based on relating in closed-form the joint queue-length at the beginning and the end of a server visit to a queue. These kernel relations are derived using the theory of absorbing Markov chains. Finally, we will show that our tool works also in the case of a tandem queueing network with a single server that can serve one queue at a time.
Abstract. In this paper, we will develop a general framework to analyze polling systems with eith... more Abstract. In this paper, we will develop a general framework to analyze polling systems with either the autonomous-server or the time-limited service discipline. We consider Poisson batch arrivals and phase-type service times. It is known that these disciplines do not satisfy the well-known branching property in polling system. Therefore, hardly any exact results exist in the literature. Our strategy is to apply an iterative scheme that is based on relating in closed-form the joint queue-length at the beginning and the end of a server visit to a queue. These kernel relations are derived using the theory of absorbing Markov chains.
Wireless sensor networks are decentralised networks consisting of sensors that can detect events ... more Wireless sensor networks are decentralised networks consisting of sensors that can detect events and transmit data to neighbouring sensors. Ideally, this data is eventually gathered in a central base station. Wireless sensor networks have many possible applications. For example, they can be used to detect gas leaks in houses or fires in a forest. In this report, we study data gathering in wireless sensor networks with the objective of minimising the time to send event data to the base station. We focus on sensors with a limited cache and take into account both node and transmission failures. We present two cache strategies and analyse the performance of these strategies for specific networks. For the case without node failures we give the expected arrival time of event data at the base station for both a line and a 2D grid network. For the case with node failures we study the expected arrival time on two-dimensional networks through simulation, as well as the influence of the broadc...
Memorandum Faculty of Mathematical Sciences, 2009
In the present article, we analyze a class of time-limited polling systems. In particular, we wil... more In the present article, we analyze a class of time-limited polling systems. In particular, we will derive a direct relation for the evolution of the joint queue-length during the course of a server visit. This will be done both for the pure and the exhaustive exponential time-limited discipline for general service time requirements and preemptive service. More specifically, service of individual customers is according to the preemptive-repeat-random strategy, i.e., if a service is interrupted, then at the next server visit a new service time will be drawn from the original service-time distribution. Moreover, we incorporate customer routing in our analysis, such that it may be applied to a large variety of queueing networks with a single server operating under one of the before-mentioned time-limited service disciplines. We study the time-limited disciplines by performing a transient analysis for the queue length at the served queue. The analysis of the pure time-limited discipline ...
Crisis situations require fast regain of control. Wireless ad-hoc networks will enable emergency ... more Crisis situations require fast regain of control. Wireless ad-hoc networks will enable emergency services to act upon the actual status of the situation by retrieving and exchanging detailed up-to-date information. Deployment of highbandwidth, robust, self-organising ad-hoc networks will therefore enable quicker response to typical hat/where/when questions, than the more vulnerable low-bandwidth communication networks currently in use. This paper addresses a number of results of the projects AAF (Adaptive Ad-hoc Freeband communications) and Easy Wireless that enable high bandwidth robust ad-hoc networking.
Wireless ad-hoc networks will enable emergency services to continuously overview and act upon the... more Wireless ad-hoc networks will enable emergency services to continuously overview and act upon the actual status of the situation by retrieving and exchanging detailed up-to-date information between the rescue workers. Deployment of high-bandwidth, robust, self-organising ad-hoc networks will enable quicker response to typical what/where/when questions, than the more vulnerable low-bandwidth communication networks currently in use. This paper addresses a number of results of the Easy Wireless project that enable high bandwidth robust ad-hoc networking. Most of the concepts presented here have been experimentally verified and/or prototyped.
Advances in Applied Probability
Polling systems are queueing systems consisting of multiple queues served by a single server. In ... more Polling systems are queueing systems consisting of multiple queues served by a single server. In this paper we analyze two types of preemptive time-limited polling systems, the so-called pure and exhaustive time-limited disciplines. In particular, we derive a direct relation for the evolution of the joint queue length during the course of a server visit. The analysis of the pure time-limited discipline builds on and extends several known results for the transient analysis of an M/G/1 queue. For the analysis of the exhaustive discipline we derive several new results for the transient analysis of the M/G/1 queue during a busy period. The final expressions for both types of polling systems that we obtain generalize previous results by incorporating customer routeing, generalized service times, batch arrivals, and Markovian polling of the server.
Annals of Operations Research, Jan 27, 2011
Advances in Applied Probability, Mar 1, 2020
Memorandum (institute of Pacific Relations, American Council), Dec 1, 2007
Processor sharing (PS) models nicely capture the bandwidth sharing and statistical multiplexing e... more Processor sharing (PS) models nicely capture the bandwidth sharing and statistical multiplexing effect of TCP at the flow-level. However, these 'rough' models do not provide insight into the impact of packet-level parameters (round trip time, buffer size) on performance metrics such as throughput and flow transfer times. In a previous paper an analytical, integrated packet/flow model was developed, exploiting the advantages of PS approach at the flow-level, while incorporating the most significant packet-level effects. In the present paper we propose an enhancement of this model, which is validated through extensive NS simulations. The numerical results show that this enhancement leads to significantly better performance approximations than the originally proposed model.
Probability in the Engineering and Informational Sciences, Mar 19, 2014
In this paper, we will develop a tool to analyze polling systems with the autonomous-server, the ... more In this paper, we will develop a tool to analyze polling systems with the autonomous-server, the time-limited, and the k-limited service discipline. It is known that these disciplines do not satisfy the well-known branching property in polling system, therefore, hardly any exact result exists in the literature for them. Our strategy is to apply an iterative scheme that is based on relating in closed-form the joint queue-length at the beginning and the end of a server visit to a queue. These kernel relations are derived using the theory of absorbing Markov chains. Finally, we will show that our tool works also in the case of a tandem queueing network with a single server that can serve one queue at a time.
Abstract. In this paper, we will develop a general framework to analyze polling systems with eith... more Abstract. In this paper, we will develop a general framework to analyze polling systems with either the autonomous-server or the time-limited service discipline. We consider Poisson batch arrivals and phase-type service times. It is known that these disciplines do not satisfy the well-known branching property in polling system. Therefore, hardly any exact results exist in the literature. Our strategy is to apply an iterative scheme that is based on relating in closed-form the joint queue-length at the beginning and the end of a server visit to a queue. These kernel relations are derived using the theory of absorbing Markov chains.
Wireless sensor networks are decentralised networks consisting of sensors that can detect events ... more Wireless sensor networks are decentralised networks consisting of sensors that can detect events and transmit data to neighbouring sensors. Ideally, this data is eventually gathered in a central base station. Wireless sensor networks have many possible applications. For example, they can be used to detect gas leaks in houses or fires in a forest. In this report, we study data gathering in wireless sensor networks with the objective of minimising the time to send event data to the base station. We focus on sensors with a limited cache and take into account both node and transmission failures. We present two cache strategies and analyse the performance of these strategies for specific networks. For the case without node failures we give the expected arrival time of event data at the base station for both a line and a 2D grid network. For the case with node failures we study the expected arrival time on two-dimensional networks through simulation, as well as the influence of the broadc...
Memorandum Faculty of Mathematical Sciences, 2009
In the present article, we analyze a class of time-limited polling systems. In particular, we wil... more In the present article, we analyze a class of time-limited polling systems. In particular, we will derive a direct relation for the evolution of the joint queue-length during the course of a server visit. This will be done both for the pure and the exhaustive exponential time-limited discipline for general service time requirements and preemptive service. More specifically, service of individual customers is according to the preemptive-repeat-random strategy, i.e., if a service is interrupted, then at the next server visit a new service time will be drawn from the original service-time distribution. Moreover, we incorporate customer routing in our analysis, such that it may be applied to a large variety of queueing networks with a single server operating under one of the before-mentioned time-limited service disciplines. We study the time-limited disciplines by performing a transient analysis for the queue length at the served queue. The analysis of the pure time-limited discipline ...
Crisis situations require fast regain of control. Wireless ad-hoc networks will enable emergency ... more Crisis situations require fast regain of control. Wireless ad-hoc networks will enable emergency services to act upon the actual status of the situation by retrieving and exchanging detailed up-to-date information. Deployment of highbandwidth, robust, self-organising ad-hoc networks will therefore enable quicker response to typical hat/where/when questions, than the more vulnerable low-bandwidth communication networks currently in use. This paper addresses a number of results of the projects AAF (Adaptive Ad-hoc Freeband communications) and Easy Wireless that enable high bandwidth robust ad-hoc networking.
Wireless ad-hoc networks will enable emergency services to continuously overview and act upon the... more Wireless ad-hoc networks will enable emergency services to continuously overview and act upon the actual status of the situation by retrieving and exchanging detailed up-to-date information between the rescue workers. Deployment of high-bandwidth, robust, self-organising ad-hoc networks will enable quicker response to typical what/where/when questions, than the more vulnerable low-bandwidth communication networks currently in use. This paper addresses a number of results of the Easy Wireless project that enable high bandwidth robust ad-hoc networking. Most of the concepts presented here have been experimentally verified and/or prototyped.
Advances in Applied Probability
Polling systems are queueing systems consisting of multiple queues served by a single server. In ... more Polling systems are queueing systems consisting of multiple queues served by a single server. In this paper we analyze two types of preemptive time-limited polling systems, the so-called pure and exhaustive time-limited disciplines. In particular, we derive a direct relation for the evolution of the joint queue length during the course of a server visit. The analysis of the pure time-limited discipline builds on and extends several known results for the transient analysis of an M/G/1 queue. For the analysis of the exhaustive discipline we derive several new results for the transient analysis of the M/G/1 queue during a busy period. The final expressions for both types of polling systems that we obtain generalize previous results by incorporating customer routeing, generalized service times, batch arrivals, and Markovian polling of the server.