Trust-region methods
Contiki - A Lightweight and Flexible Operating System for Tiny Networked Sensors
LCN '04 Proceedings of the 29th Annual IEEE International Conference on Local Computer Networks
Adversarial contention resolution for simple channels
Proceedings of the seventeenth annual ACM symposium on Parallelism in algorithms and architectures
Performance of a Beacon Enabled IEEE 802.15.4 Cluster with Downlink and Uplink Traffic
IEEE Transactions on Parallel and Distributed Systems
Telos: enabling ultra-low power wireless research
IPSN '05 Proceedings of the 4th international symposium on Information processing in sensor networks
Analysis of the contention access period of IEEE 802.15.4 MAC
ACM Transactions on Sensor Networks (TOSN)
International Journal of Communication Systems - Energy-Efficicent Network Protocols and Algorithms for Wireless Sensor Networks
An Adaptive GTS Allocation Scheme for IEEE 802.15.4
IEEE Transactions on Parallel and Distributed Systems
An optimal GTS scheduling algorithm for time-sensitive transactions in IEEE 802.15.4 networks
Computer Networks: The International Journal of Computer and Telecommunications Networking
Modeling IEEE 802.15.4 based wireless sensor network with packet retry limits
Proceedings of the 5th ACM symposium on Performance evaluation of wireless ad hoc, sensor, and ubiquitous networks
Markov Chain-based performance analysis of multihop IEEE 802.15.4 wireless networks
Performance Evaluation
Performance analysis of GTS allocation in beacon enabled IEEE 802.15.4
SECON'09 Proceedings of the 6th Annual IEEE communications society conference on Sensor, Mesh and Ad Hoc Communications and Networks
Throughput analysis and improvement of hybrid multiple access in IEEE 802.15.3c mm-wave WPAN
IEEE Journal on Selected Areas in Communications - Special issue on realizing GBPS wireless personal area networks
Fundamentals of Queueing Theory
Fundamentals of Queueing Theory
Performance Analysis of Slotted Carrier Sense IEEE 802.15.4 Medium Access Layer
IEEE Transactions on Wireless Communications
Commercial Applications of Wireless Sensor Networks Using ZigBee
IEEE Communications Magazine
Performance analysis of the IEEE 802.11 distributed coordination function
IEEE Journal on Selected Areas in Communications
IEEE 802.11 protocol: design and performance evaluation of an adaptive backoff mechanism
IEEE Journal on Selected Areas in Communications
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To offer flexible quality of service to several classes of applications, the medium access control (MAC) protocol of IEEE 802.15.4 wireless sensor networks (WSNs) combines the advantages of a random access with contention with a time division multiple access (TDMA) without contention. Understanding reliability, delay, and throughput is essential to characterizing the fundamental limitations of the MAC and optimizing its parameters. Nevertheless, there is not yet a clear investigation of the achievable performance of hybrid MAC. In this article, an analytical framework for modeling the behavior of the hybrid MAC protocol of the IEEE 802.15.4 standard is proposed. The main challenge for an accurate analysis is the coexistence of the stochastic behavior of the random access and the deterministic behavior of the TDMA scheme. The analysis is done in three steps. First, the contention access scheme of the IEEE 802.15.4 exponential back-off process is modeled through an extended Markov chain that takes into account channel, retry limits, acknowledgements, unsaturated traffic, and superframe period. Second, the behavior of the TDMA access scheme is modeled by another Markov chain. Finally, the two chains are coupled to obtain a complete model of the hybrid MAC. By using this model, the network performance in terms of reliability, average packet delay, average queuing delay, and throughput is evaluated through both theoretical analysis and experiments. The protocol has been implemented and evaluated on a testbed with off-the-shelf wireless sensor devices to demonstrate the utility of the analysis in a practical setup. It is established that the probability density function of the number of received packets per superframe follows a Poisson distribution. It is determined under which conditions the guaranteed time slot allocation mechanism of IEEE 802.15.4 is stable. It is shown that the mutual effect between throughput of the random access and the TDMA scheme for a fixed superframe length is critical to maximizing the overall throughput of the hybrid MAC. In high traffic load, the throughput of the random access mechanism dominates over TDMA due to the constrained use of TDMA in the standard. Furthermore, it is shown that the effect of imperfect channels and carrier sensing on system performance heavily depends on the traffic load and limited range of the protocol parameters. Finally, it is argued that the traffic generation model established in this article may be used to design an activation timer mechanism in a modified version of the CSMA/CA algorithm that guarantees a stable network performance.