Deterministic And Synchronous Multi-channel Extension Research Articles

A Comprehensive Performance Comparison of IEEE 802.15.4 DSME and TSCH in a Realistic IoT Scenario for Industrial Applications

In the Industrial Internet of Things (i.e., IIoT), the standardization of open technologies and protocols has achieved seamless data exchange between machines and other physical systems from different manufacturers. At the MAC sublayer, the industry-standard protocols IEEE 802.15.4 Time Slot Channel Hopping (TSCH) and Deterministic and Synchronous Multi-channel Extension (DSME) show promising properties for high adaptability and dynamically changing traffic. However, performance comparison between these MAC protocols rarely has gone beyond a simulation phase. This work presents the results of such a comparison on physically deployed networks using the facilities of the FIT-IoTLab. The evaluation includes fully implementing an IIoT protocol stack based on MQTT in Contiki-NG. It comprises the integration of DSME as part of Contiki-NG’s software stack through OpenDSME, the only publicly available implementation of DSME. Results show that both protocols suit IIoT applications, particularly for data collection. The comparison between TSCH and DSME also includes an evaluation of distributed schedulers for both MAC modes and one autonomous scheduler for TSCH within a UDP protocol stack.

A Beacon and GTS Scheduling Scheme for IEEE 802.15.4 DSME Networks

The IEEE 802.15.4 standard is one of the widely adopted networking specification for realizing different applications of Internet of Things (IoT). It defines several physical layer options and Medium Access Control (MAC) sub-layer protocols for low-power devices supporting low-data rates. One such MAC protocol is the Deterministic and Synchronous Multi-channel Extension (DSME), which addresses the limitation on maximum number of Guaranteed Time Slots (GTSs) in 802.15.4-2011 MAC, and provides channel diversity to increase network robustness. However, beacon scheduling in peer-to-peer networks suffers from beacon slot-collisions when two or more coordinators simultaneously compete for the same vacant beacon slot. In addition, the standard does not explore DSME-GTS scheduling across multiple channels. This paper addresses the beacon slot collision problem by proposing a non-conflicting beacon scheduling mechanism using association order. Further, a distributed multi-channel DSME-GTS schedule is proposed that optimally assigns DSME-GTSs across different channels. The objective is to minimize the number of times-lots used while maximizing the usage of available channels. Through simulations, the proposed mechanisms’ performance is analyzed in terms of energy efficiency, transmission overhead, scheduling efficiency, throughput, and latency and is shown to out-perform the other existing schemes.

Modeling and analysis of priority and range‐based‐deterministic and synchronous multichannel extension‐guaranteed time slot allocation in IEEE 802.15.4e medium access control protocol

AbstractInternet of Things (IoT) enabled technology in the current applications such as smart grids, smart cities, and smart health sectors utilize wireless sensor networks (WSN) to establish stable and reliable communication between the nodes. Moreover, the primary requirement of WSN in IoT applications is to provide low‐rate data communication. The IEEE 802.15.4e standard‐based medium access control (MAC) protocol is found suitable for low‐rate data communication in WSN. The IEEE 802.15.4e standard adopts a deterministic and synchronous multichannel extension (DSME) MAC protocol which employs a multisuperframe structure with multichannel data transmission during the contention free period. However, the guaranteed time slot (GTS) allocation process in DSME employed by the standard may not be suitable for an adaptive traffic network scenario that has a direct impact on the throughput and bandwidth utilization. In this article, we develop a priority and range‐based DSME‐GTS allocation algorithm based on the priorities of end nodes and range estimation. Furthermore, the proposed algorithm is developed for the two types of network scenarios encountered in a star topology‐enabled WSN. In scenario‐1, the slots allocation process is carried out based on the priorities of end nodes. Next, in scenario‐2, the slots allocation process is carried out based on the range estimation of end nodes. Detailed mathematical modeling of the proposed methodology is provided for the various performance metrics. The model is validated using the MATLAB 2017a programming tool. Simulation results show that the proposed methodology outperforms the existing DSME‐GTS approaches in terms of performance metrics such as packet delivery ratio, end‐to‐end delay, packet loss ratio, throughput, delay, bandwidth utilization, and the energy consumption.

Performance comparison of IEEE 802.15.4 and IEEE 802.15.4e based MAC algorithm in wireless body sensor networks

One of the potential applications of Wireless Sensor Network for improving the lifestyle of human beings is Wireless Body Sensor Network (WBSN). A dedicated health monitoring system is referred to as the Ubiquitous Health Monitoring (UHM) system consisting of the Internet of Things (IoT) based access points which are made available in a cloud-based server. So, ZigBee based IEEE 802.15.4 technology is extensively used in the implementation of Medium Access Control (MAC) and Physical (PHY) layers. Hence, a comparison is provided in terms of the features of the modified IEEE 802.15.4e standard. An algorithmic approach for the MAC layer helped in regulated power consumption of the sensor node by controlling the transmission power for the packets. This is initiated in the algorithm by categorizing the packets as Delay sensitive and Delay insensitive. By regulating the channel access strategy using Medium Access Control (MAC) layer, the energy consumption of the transceiver reduces, thus improving the energy consumption of the communication system and lifetime of the sensor network. For better throughput using IEEE 802.15.4e, the performance of Deterministic and Synchronous Multi-channel Extension (DSME) is found to be trustworthy than Time Slotted Channel Hopping (TSCH).

Traffic-Adaptive CFP Extension for IEEE 802.15.4 DSME MAC in Industrial Wireless Sensor Networks

This paper presents a traffic-adaptive contention-free period (CFP) extension (TaCFPext) protocol for IEEE 802.15.4 deterministic and synchronous multichannel extension (DSME) medium access control (MAC), which aims to satisfy the traffic adaptability requirement of industrial wireless sensor networks (IWSNs). The legacy DSME standard has limitations in accommodating highly varying traffic load in IWSNs due to its fixed multi-superframe structure. TaCFPext enables a node to adaptively use a contention access period (CAP) as an extended CFP (extCFP) on the demands of traffic loads in a distributed manner. The node starts TaCFPext when it determines that the CFP of the current multi-superframe is insufficient to accommodate the traffic load. Then, the node selects a CAP to be used as an extCFP, on which it is allocated an extended guaranteed time slot (extGTS). When the traffic load decreases, the extGTS is deallocated before the GTS in CFP, and the extCFP returns to CAP again. An experimental simulation was performed to verify the superiority of TaCFPext. The results demonstrated that TaCFPext outperforms the legacy DSME for aggregate throughput and average delay under various traffic conditions.

Performance Enhancement of IEEE 802.15.4e Deterministic and Synchronous Multi-Channel Extension

Deterministic and Synchronous multi-channel extension (DSME) is introduced to improve the network performance by providing dedicated slots. Thus, the network is divided into various slots to access the channel in the dedicated slots allocated to them. However, choosing the DSME slots is one of the major challenging tasks. In this article, we use fuzzy logic to estimate the optimum count of DSME slot per super frame by considering network size, collision probability, and modulation and coding schemes. Further, we analytically evaluate the collision probability, throughput, energy consumption and delay of DSME mechanism. Results show that the optimal number of DSME slots found using fuzzy logic significantly enhances the throughput and decreases the energy consumption. Finally, extensive simulations are conducted using ns-3 to validate the analytical result

A Novel Grouping Mechanism for DSMEMAC Mode

IEEE 802.15.4e introduces deterministic and Synchronous multi-channel extension (DSME) MAC mode to provide deterministic performance. To do so, the super frame structure is divided into multiple contention access slots and contention free slots. However, the standard does not specify the number of devices to access each DSME slots. In this article, we exploit fuzzy logic to group the devices based on the nature of traffic and vary the duration of DSME slot according to the traffic requirements of the devices. Further, we analytically evaluate the collision probability, throughput, energy consumption and delay of DSME mechanism. Results show that the optimal amount of DSME slots associated with fuzzy logic significantly improves efficiency and reduces energy usage.. Finally, extensive simulations are conducted using ns-3 to validate the analytical results.

Novel Extensions to Enhance Scalability and Reliability of the IEEE 802.15.4-DSME Protocol

The Deterministic and Synchronous Multichannel Extension (DSME) of the IEEE 802.15.4 standard was designed to fulfill the requirements of commercial and industrial applications. DSME overcomes the IEEE 802.15.4 limitation on the maximum number of Guaranteed Time Slots (GTS) in a superframe and it also exploits channel diversity to increase the communication reliability. However, DSME suffers from scalability problems, as its multi-superframe structure does not efficiently handle GTS in networks with a high number of nodes and periodic flows. This paper proposes the enhanceD DSME (D-DSME), which consists of two extensions that improve the DSME scalability and reliability exploiting a GTS within the multi-superframe to accommodate multiple flows or multiple retransmissions of the same flow. The paper describes the proposed extensions and the performance results of both OMNeT simulations and experiments with real devices implementing the D-DSME.

A Performance-to-Cost Analysis of IEEE 802.15.4 MAC With 802.15.4e MAC Modes

The IEEE 802.15.4 standard is one of the widely adopted networking specification for Internet of Things (IoT). It defines several physical layer (PHY) options and medium access control (MAC) sub-layer protocols for interconnection of constrained wireless devices. These devices are usually battery-powered and need to support requirements like low-power consumption and low-data rates. The standard has been revised twice to incorporate new PHY layers and improvements learned from implementations. Research in this direction has been primarily centered around improving the energy consumption of devices. Recently, to meet specific Quality-of-Service (QoS) requirements of different industrial applications, the IEEE 802.15.4e amendment was released that focuses on improving reliability, robustness and latency. In this paper, we carry out a performance-to-cost analysis of Deterministic and Synchronous Multi-channel Extension (DSME) and Time-slotted Channel Hopping (TSCH) MAC modes of IEEE 802.15.4e with 802.15.4 MAC protocol to analyze the trade-off of choosing a particular MAC mode over others. The parameters considered for performance are throughput and latency, and the cost is quantified in terms of energy. A Markov model has been developed for TSCH MAC mode to compare its energy costs with 802.15.4 MAC. Finally, we present the applicability of different MAC modes to different application scenarios.

Improving network formation in IEEE 802.15.4e DSME

Wireless Sensor and Actuator Networks are becoming attractive also for industrial applications, since recent standardization efforts have introduced significant improvement to reliability and deterministic communication delays. In this context, IEEE 802.15.4e is widely considered the major improvement, introducing many enhancements to the original IEEE 802.15.4 standard aimed at supporting critical applications. Among the new defined MAC protocols, Deterministic and Synchronous Multi-channel Extension (DSME) represents the most suitable option for applications with time-varying requirements. In this paper, an analysis of the IEEE 802.15.4 DSME MAC protocol during network formation is presented. The goal is to study the protocol performance and propose solutions to reduce the network formation time, improving energy and resource efficiency. To carry out the performance evaluation, DSME has been fully implemented in Contiki OS, an actual operating system for sensor nodes. The study has highlighted issues and inefficiencies in the network formation process, allowing to consequently propose effective solutions. In particular, it is proposed a set of guidelines for DSME configuration to the original MAC protocol that are proved to increase significantly the network formation efficiency.

A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks.

IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly.

Analysis and Enhancement of IEEE 802.15.4e DSME Beacon Scheduling Model

In order to construct a successful Internet of things (IoT), reliable network construction and maintenance in a sensor domain should be supported. However, IEEE 802.15.4, which is the most representative wireless standard for IoT, still has problems in constructing a large-scale sensor network, such as beacon collision. To overcome some problems in IEEE 802.15.4, the 15.4e task group proposed various different modes of operation. Particularly, the IEEE 802.15.4e deterministic and synchronous multichannel extension (DSME) mode presents a novel scheduling model to solve beacon collision problems. However, the DSME model specified in the 15.4e draft does not present a concrete design model but a conceptual abstract model. Therefore, in this paper we introduce a DSME beacon scheduling model and present a concrete design model. Furthermore, validity and performance of DSME are evaluated through experiments. Based on experiment results, we analyze the problems and limitations of DSME, present solutions step by step, and finally propose an enhanced DSME beacon scheduling model. Through additional experiments, we prove the performance superiority of enhanced DSME.