While decentralized medium access control (MAC) protocols are more popular in wireless networks, cluster based sensor networks are particularly amenable to centralized, polling based protocols. This paper presents an analytic model to evaluate the performance of a polling based MAC protocol in terms of the packet delay, buffer overflow rates and energy consumption. We show that the polling base...

Throughout this internship report, polling systems play a central role. Polling systems are queueing systems consisting of multiple queues, attended by a single server. The server can only serve one queue at a time. Whenever the server moves from one queue to another, a stochastic, non-zero switch-over time is incurred. The server never idles; even when there are no customers waiting in the who...

Energy consumption is a perennial issue in the design of wireless sensor networks (WSNs) which typically rely on portable sources like batteries for power. Recent advances in ambient energy harvesting technology have made it a potential and promising alternative source of energy for powering WSNs. By using energy harvesters with supercapacitors, WSNs are able to operate perpetually until hardwa...

Queueing systems with a single server in which customers wait to be served at a finite number of distinct locations (buffers/queues) are called discrete polling systems. Polling systems in which arrivals of users occur anywhere in a continuum are called continuous polling systems. Often one encounters a combination of the two systems: the users can either arrive in a continuum or wait in a fini...

Polling systems have been extensively studied, and have had many applications. They have often been used for studying wired local areas networks (such as token passing rings) and wireless local area networks (such as bluetooth). In this work we relax one of the main restrictions on the statistical assumptions under which polling systems have been analyzed. Namely, we allow correlation between w...

A hierarchical polling-based access scheme for Wireless Body Sensor Network (WBSN) is proposed in this paper. The proposed access scheme is structured in hierarchy to collect data from sensor nodes inserted in human body. In first level of hierarchy the sensor nodes are divided into groups and sensor nodes of each group communicate with a sink node which collects data by using polling technique...

This paper deals with the stability of periodic polling models with mixed service policies. The interarrivals to all queues are independent and exponentially distributed and the service and the switch-over times are independent with general distributions. The necessary and suucient condition for the stability of such polling systems is established. The proof is based on the stochastic monotonic...

A QoS supportive Adaptive Polling (QAP) protocol for wireless LANs is introduced. QAP operates under an infrastructure wireless LAN, where an Access Point (AP) polls the wireless nodes in order to grant them permission to transmit. The polled node sends data directly to the destination node. We consider bursty traffic conditions, under which the protocol operates efficiently. The polling scheme...

The purpose of this study was to investigate the effect of polling technologies (clickers or tablets) integrated with strategies (individual or group) on students’ academic performance, anxiety, and attention. The participants were 34 students enrolled in an educational research methodology course. The anxiety scale, preand in-class quizzes, brainwaves of attention levels, open-ended questionna...

We consider the problem of minimizing average paging cost subject to delay constraints in a wireless system. Previous work assumed the unit to be found did not move during the paging process whereas here the unit may change location during polling events. We show that the conditionally most probable locations, given that the unit has not yet been found, should be searched first. We find the opt...