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The load balancing problem is one of an open issues for the cloud computing. A good load balancing mechanism enhances the performance of network processing, optimizes the use of resources, and ensures that no overloading a single node or link case. The existing load balancing cloud computing research mainly unilateral the fairness of the transmission network or stand only for the system. Hence, this...
A challenging issue in data collection in duty-cycled wireless sensor networks (DC-WSNs) is the trade-off between lifetime and latency. Indeed, duty-cycling has long been a critical mechanism for energy conservation in WSNs where the sensor nodes switch between active and dormant states. Moreover, this mechanism involves strong sleep latencies leading to severe end-to-end delay degradation. In this...
We provide an improved bound for the expectation of the stationary delay under the maximum weight scheduling (MWS) policy in one-hop wireless networks. In the model, the interference of the links is characterized by an interference graph G=(V, E). For a vector μ ∊ R|V|+, let χf (G, μ) be the weighted fractional coloring number for the graph G under the weight vector μ. For an arrival rate vector λ...
We provide bounds for the expectations of the stationary delay and the sum of the stationary queue sizes under the approximate maximum weight scheduling (MWS) policy and under the longest-queue-first (LQF) policy in one-hop wireless networks. For MWS, our results improves the previously provided bounds; for LQF, the results are new. In the derivation of the new bounds, a connection with certain graph...
We present Duo-MAC, an asynchronous cascading wake-up scheduled MAC protocol for heterogeneous traffic forwarding in low-power wireless networks. Duo-MAC deals with energy-delay minimization problem and copes with transmission latency encountered by Today's duty-cycled protocols when forwarding heterogeneous traffic types. It switches, according to the energy and delay requirements, between Low Duty...
Testing of a system-on-chip (SoC) consists of a schedule of test sessions. In each session, a subset of cores of the SoC is tested such that the peak power consumption of each core as well as that of the entire SoC remain under specified limits. In this work, we assume that each test session can be assigned its own clock frequency and VDD, which are related through the critical path delay constraint...
The focus of this paper is on the co-design of control and communication protocol for the control of multiple applications with unknown parameters using a distributed embedded system. The co-design consists of an adaptive switching controller and a hybrid communication architecture that switches between a time-triggered and event-triggered protocol. It is shown that the overall co-design leads to...
In this paper we discuss the rescheduling of trains on a large-scale railway network in the case of perturbations using a max-plus-linear system description. We study the structure of the system matrices and derive how this structure can be manipulated by the control variables. In addition, we show that this leads to a system matrix that is affine in the control variables and the timing parameters...
Data aggregation from a set of sensors to a common sink over a tree-based routing topology is a fundamental traffic pattern in wireless sensor networks (WSNs). The time division multiple access (TDMA)-based scheduling protocols are suitable for such data aggregation applications. Most of the previously proposed TDMA schemes focus on a particular objective, such as minimizing schedule delay, latency,...
In this paper we propose a methodology which combines Forward and Backward Simulation in order to extend discrete-event simulation by the ability to calculate float times. In the case of Backward Simulation, the simulation starts at the virtual completion date of the construction project and runs backwards in time until the start date. To determine float times it is important that the task execution...
The smart grid is envisioned to significantly enhance the efficiency of energy consumption, by utilizing two-way communication channels between consumers and operators. For example, operators can opportunistically leverage the delay tolerance of energy demands in order to balance the energy load over time, and hence, reduce the total operational cost. This opportunity, however, comes with security...
Carrier Sense Multiple Access (CSMA) has been widely used as a medium access control (MAC) scheme in wireless networks mainly due to its simple and totally distributed operations. Recently, it has been reported in the community that even such simple CSMA-type algorithms can achieve optimality in terms of throughput and utility, by smartly controlling its operational parameters such as backoff and...
Large-scale applications expressed as scientific workflows are often grouped into ensembles of inter-related workflows. In this paper, we address a new and important problem concerning the efficient management of such ensembles under budget and deadline constraints on Infrastructure- as-aService (IaaS) clouds. We discuss, develop, and assess algorithms based on static and dynamic strategies for both...
Energy consumption is one of the main concerns that refrain users from fully exploiting their smart phone capabilities. Guided by energy measurements on smart phones, which show that some services performed in parallel require less energy than their stand-alone executions, we investigate the possibility to delay some services to the time when other services have already been scheduled in such a way...
Airborne networks often use frequency hopping to be jam resistant. Because users are highly mobile and can have large propagation delays, otherwise orthogonal frequency hopping patterns appear asynchronous, and hop-by-hop collisions will occur. We compare the achievable throughput and delay of scheduling schemes versus random access schemes in this context via modeling and simulation. Because collisions...
The use of beamforming antennas has received significant attention over the last decade. We consider beamforming applied to dynamic operations such as networked UAV hubs which interconnect with users on the ground. The key problem involves scheduling these communications with users serviced by different beam patterns. This paper develops a linear program to optimally allocate time to beams for client...
The Virtual Coordinate Multiple Access (VCMA) protocol is introduced and analyzed. VCMA is a medium access control protocol that defines transmissions schedules dynamically based on the assignment and exchange of virtual coordinates relative to an elected root node in a mesh network. VCMA is shown to attain feasible transmission schedules within a finite time, and its channel access delay properties...
This paper proposes message scheduling on dedicated time slot of ISA100.11a to satisfy real time property. In this paper, a superframe is designed to accommodate periodic real time (PRT) message, aperiodic real time (alarm) message, and non real time (NRT) message. To do so, a superframe is divided into dedicated time slot (DTS) which is used to send PRT message and shared time slot (STS) which is...
This paper describes operations and procedures envisioned for NASA's Air Traffic Management (ATM) Technology Demonstration #1 (ATD-1). The ATD-1 Concept of Operations (ConOps) demonstration will integrate three NASA technologies to achieve high throughput, fuel-efficient arrival operations into busy terminal airspace. They are Traffic Management Advisor with Terminal Metering (TMA-TM) for precise...
To ensure sustainable operations of wireless sensor networks, environmental energy harvesting has been well recognized as one promising solution for long-term applications. Unlike in battery-powered sensor networks, we are targeting a duty-cycle adjustment to optimize the network performance, e.g., delay minimization, with full harvested energy utilization. In this paper, we introduce a set of duty-cycle...
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