Bandwidth and Energy Consumption Tradeoff for IEEE 802.15.4 in Multihop Topologies

IEEE 802.15.4, Multi-hop,ZigBee,WSNwe analyze IEEE 802.15.4 mechanisms including node organization, MAC mechanisms, energy conservation, topology construction and node association. We detail how we should modify IEEE 802.15.4 to cope efficiently with multihop topologies, scheduling the transmissions. We quantify the impact of the cluster-tree algorithm on the network performances. We expose how the overall throughput can be improved with a novel cluster-tree construction algorithm defined formally as a Mixed Integer Linear Programming formulation. We quantify the impact of each parameter on the performances of IEEE 802.15.4. In particular, we present a self-configuration algorithm to dynamically adjust the Backoff Exponent so that the protocol always operates in optimal conditions

IEEE 802.15.4e: a Survey

Several studies have highlighted that the IEEE 802.15.4 standard presents a number of limitations such as low reliability, unbounded packet delays and no protection against interference/fading, that prevent its adoption in applications with stringent requirements in terms of reliability and latency. Recently, the IEEE has released the 802.15.4e amendment that introduces a number of enhancements/modifications to the MAC layer of the original standard in order to overcome such limitations. In this paper we provide a clear and structured overview of all the new 802.15.4e mechanisms. After a general introduction to the 802.15.4e standard, we describe the details of the main 802.15.4e MAC behavior modes, namely Time Slotted Channel Hopping (TSCH), Deterministic and Synchronous Multi-channel Extension (DSME), and Low Latency Deterministic Network (LLDN). For each of them, we provide a detailed description and highlight the main features and possible application domains. Also, we survey the current literature and summarize open research issues

LBS: A Beacon Synchronization Scheme With Higher Schedulability for IEEE 802.15. 4 Cluster-Tree-Based IoT Applications

[EN] The IEEE 802.15.4 standard is one of the most widely used link layer technology for building Internet of Things (IoT). It specifies several physical layer options and MAC layer for meeting low-power and low-rate requirements of devices deployed in a network of IoT. The standard also specifies a synchronization scheme for devices connected in a star topology, operating in beacon-enabled (BE) mode using periodic beacons. The BE mode facilitates synchronization among devices for data transmission and is suitable for large networks to establish low duty-cycles. Absence of a such a scheme for a cluster-tree network has confined its application only to nonbeacon mode. The challenge here is to schedule beacon frame transmissions of multiple devices in a nonoverlapping manner to avoid beacon collisions. This paper tackles the problem of synchronization by proposing localized beacon synchronization (LBS) scheme, a distributed technique for beacon scheduling in cluster-tree network topologies. LBS uses 2-hop information and association order to compute beacon transmission offsets that better utilize the available time slots, incur fewer transmissions, and is highly scalable. Further, we analytically show that the schedulability of the proposed scheme is higher compared to other related schemes. In addition, we also address the important issue of resynchronization that has been ignored in all of the prior works. The proposed resynchronization mechanisms consider the interdependencies between synchronization and duty-cycling schemes and are shown to significantly lower the synchronization overhead when synchronization among devices is lost.This work was supported by the Science and Engineering Research Board, Department of Science and Technology, Govt. of India, under Grant ECR/2016/001651.Choudhury, N.; Matam, R.; Mukherjee, M.; Lloret, J. (2019). LBS: A Beacon Synchronization Scheme With Higher Schedulability for IEEE 802.15. 4 Cluster-Tree-Based IoT Applications. IEEE Internet of Things. 6(5):8883-8896. https://doi.org/10.1109/JIOT.2019.2924317888388966

Multi-channel Utilization Algorithms for IEEE 802.15.4 based Wireless Network: A Survey

In the pass years, IEEE 802.15.4 based Wireless Sensor Networks (WSNs) have received great attention and have been employed in many areas such as inventory checking, local monitoring and alarming etc. One of the key issues affecting WSN's system performance is interference caused by devices operating with the same or different standards on the overlapping frequency within the 2.4 GHz ISM band. This paper addresses the coexistence problem, which is the key motivation for the necessity of flexible channel usage. A review of existing approaches being proposed to date supporting multi-channel utilization in IEEE 802.15.4 based WSNs is categorized and discussed. The paper also presents major functionalities needed in implementing multi-channel utilization

Dynamic cluster scheduling for cluster-tree WSNs

While Cluster-Tree network topologies look promising for WSN applications with timeliness and energy-efficiency requirements, we are yet to witness its adoption in commercial and academic solutions. One of the arguments that hinder the use of these topologies concerns the lack of flexibility in adapting to changes in the network, such as in traffic flows. This paper presents a solution to enable these networks with the ability to self-adapt their clusters’ duty-cycle and scheduling, to provide increased quality of service to multiple traffic flows. Importantly, our approach enables a network to change its cluster scheduling without requiring long inaccessibility times or the re-association of the nodes. We show how to apply our methodology to the case of IEEE 802.15.4/ZigBee cluster-tree WSNs without significant changes to the protocol. Finally, we analyze and demonstrate the validity of our methodology through a comprehensive simulation and experimental validation using commercially available technology on a Structural Health Monitoring application scenario

Beacon Advertising in an IEEE 802.15.4e TSCH Network for Space Launch Vehicles

International audienceIn space launch vehicles, a NASA study shows that the mass per channel of 0.45 kg for a wiring approach can be reduced to 0.09 kg for a wireless approach. 8 A question arises: which wireless technology is able to meet the requirements of space launch vehicles in terms of latency, throughput and robustness. The IEEE 802.15.4e amendment has been designed to meet such requirements. More specifically, the Time Slotted Channel Hopping (TSCH) mode has been designed for industrial automation, process control and equipment monitoring. It supports multichannel and multihop communications and uses a slotted medium access on several channels. In this paper, we focus on the time needed by a joining node to detect beacons advertising the TSCH network. An Enhanced beacon is a TSCH frame that contains information on synchronization, channel hopping and timeslot used in the advertised network. However, the advertising policy is left unspecified by the IEEE 802.15.4e standard and is under the responsibility of a layer upper than the MAC one. Since beacons are broadcast, they are lost in case of collisions: the vital information they carry is lost. The main problem is how to avoid collisions between two devices that are not neighbors. In this paper, we propose a Deterministic Beacon Advertising Algorithm, called DBA. The goal of DBA is to ensure that beacons are transmitted on all frequencies used by the TSCH network, regularly and without collision. With DBA, the exact value for the maximum time for a joining node to detect a beacon can be computed easily. We use the NS3 Simulator to evaluate this time as well as the the number of message losses, considering different network topologies (star or multihop). We compare the performance of DBA with this of two algorithms existing in the state of the art

Clustered Coordinator SABTS (CC-SABTS) for Beacon Transmission in IEEE802.15.4 LR-WPAN

IEEE802.15.4 standard for Wireless Sensor Network (WSN) provides low-power transmission in the low-rate wireless personal area network (WPAN). It has three types of topology: star, peer-to-peer and cluster tree. Star topology has limit to expand network. Peer-to-peer topology has a complex multihop routing during network expansion due to the large number of full-function devices. A full-function device can act as coordinator and personal area network coordinator (PAN-C). Cluster tree topology is preferable because it can expand networks using less number of full-function devices and thus reduces complexity in routing messages. A cluster tree topology consists of a wireless PAN-C, several cluster coordinators and a number of end devices. The coordinators periodically transmit beacon frames to one another to allow synchronization and communication. However, collision will happen if the coordinators transmit beacon frames at the same time and will degrade the network performance. Different mechanisms have been introduced to solve the collision problem and one of the mechanisms is superframe adjustment and beacon transmission scheme (SABTS). SABTS calculates the precise time for beacon transmission by assigning an accurate value of beacon order and superframe order for PAN-C, cluster coordinators and end devices. As the number of cluster coordinator increases, SABTS method reiterates the calculation for beacon transmission time numerously. Hence, in order to decrease the iteration, this paper introduces clustered coordinator SABTS (CC-SABTS) by clustering coordinator nodes that are separated by two length radius. The performance of CC-SABTS is simulated and evaluated using NS2 simulation software. Result shows that CC-SABTS provides better average throughput, packet delivery ratio and end-to-end delay compared to the conventional SABTS

Multi-channel Communication in Wireless Networks

Multi-channel communication has been developed to overcome some limitations related to the throughput and delivery rate which become necessary for many applications that require sufficient bandwidth to transmit a large amount of data in Wireless Networks (WNs) such as multimedia communication. However, the requirement of frequent negotiation for the channels assignment process incurs extra-large communication overhead and collisions, which results in the reduction of both communication quality and network lifetime. This effect can play an important role in the performance deterioration of certain WNs types, especially the Wireless Sensor Networks (WSNs) since they are characterized by their limited resources. This work addresses the improvement of communication in multi-channel WSNs. Consequently, four protocols are proposed. The first one is the Multi-Channel Scheduling Protocol (MCSP) for wireless personal networks IEEE802.15.4, which focuses on overcoming the collisions problem through a multi-channel scheduling scheme. The second protocol is the Energy-efficient Reinforcement Learning (RL) Multi-channel MAC (ERL MMAC) for WSNs, which bases on the enhancement of the energy consumption in WSNs by reducing collisions and balancing the remaining energy between the nodes using a singleagent RL. The third work is the proposition of a new heuristically accelerated RL protocol named Heuristically Accelerated Reinforcement Learning approach for Channel Assignment (HARL CA) for WSNs to reduce the number of learning iterations in an energy-efficient way taking into account the bandwidth aspect in the scheduling process. Finally, the fourth contribution represents a proposition of a new cooperative multi-agent RL approach for Channel Assignment (CRLCA) in WSNs, which improves cooperative learning using an accelerated learning model, and overcomes the extra communication overhead problem of the cooperative RL using a new method for self-scheduling and energy balancing. The proposed approach is performed through two algorithms SCRLCA and DCRLCA for Static and Dynamic performance respectively. The proposed protocols and techniques have been successfully evaluated and show outperformed results in different cases through several experiments

Analyse des performances d'un réseau de capteurs exploitant le standard IEEE 802.15.4

Les réseaux de capteurs suscitent un engouement croissant du fait du grand nombre d'applications mais également des défis inhérents à ce genre de réseaux. Le standard IEEE 802.15.4 a été proposé afin de standardiser les couches physique et MAC. Dans ce travail nous avons dans un premier temps proposé une variante multi-canal pour le standard 802.15.4 permettant de résoudre le problème de collisions de supertrames. Pour cela nous proposons de construire un réseau en arbre avec la particularité que chaque cellule du réseau utilise un canal différent permettant ainsi une réduction conséquente des interférences et augmente la capacité du réseau. Nous avons également introduit un nouveau mécanisme de construction de topologie, d'allocation de canal et d'ordonnancement de supertrames nécessaire au bon fonctionnement d'une telle solution. Dans un deuxième temps nous avons analysé l'impact des différents paramètres de la méthode d'accès du standard. Nous avons mis en exergue les faiblesses de la méthode d'accès dont les performances baissent drastiquement pour des réseaux trop importants. Partant de ce constat, nous avons proposé des mécanismes d'auto-adaptation pour la méthode d'accès du standard. Ces derniers permettent d'adapter dynamiquement la taille des fenêtres de contention en fonction des conditions de trafic observées sur le canal. Le calcul des valeurs optimales est exécuté par chaque coordinateur pour résoudre le problème de surdité. Ces mécanismes sont distribués et convergent rapidement même en cas de trafic en rafales.An increasing interest has been observed in Wirless Sensor Network that can be explained by wide range of WSN applications as well as by the challenges involving the constraints of this type of networks. The IEEE 802.15.4 standard has been proposed with the objective of standardizing the physical and MAC layers. In this work, we have firstly proposed an alternative multichannel scheme for the IEEE 802.15.4 standard. It is able to solve the problem of superframe collisions based on a cluster-tree topology approach in which each cluster uses a different channel allowing the reduction of the interference and increased network capacity. We have also difined a novel mechanism for topology construction, channel allocation, and superframe scheduling. Secondly, we have analyzed the impact of different parameters on the medium access control. We have shown the weakness of the medium access method proposed in the standard. For instance, we have observed a decrease in performance when the standard is applied in large networks. Motivated by the analysis and its results we have then proposed auto-adaptive mechanisms for the medium access control. They allow to dynamically adapt the size of the contention window according to the observed traffic conditions. Each coordinator computes the optimal values to avoid deafness. The proposed mechanisms rapidly converge even in the case of bursty traffic.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF