Priority Based Centralized Scheduling for Time Slotted Channel Hopping Based Multihop IEEE 802.15.4 Networks

2020 ◽  
Vol 17 (1) ◽  
pp. 363-372
Author(s):  
K. M. Martin ◽  
B. Seetha Ramanjaneyulu
Keyword(s):  
Low Power ◽  
Ieee 802.15.4 ◽  
Scheduling Algorithms ◽  
Industrial Applications ◽  
Mac Protocols ◽  
Access Methods ◽  
Wireless Applications ◽  
Channel Hopping ◽  
Time Critical ◽  
Ieee 802.15.4E

To meet the growing demands of low power and determinism in Industrial Wireless applications, IEEE defined IEEE 802.15.4e amendment that includes many channel access methods. Time Slotted Channel Hopping protocol is one of the most popular MAC protocols under IEEE 802.15.4e. However, scheduling of time slots for time slotted channel hopping, was not part of the protocol and so different scheduling algorithms were proposed by researchers. A new time slotted channel hopping scheduling mechanism that considers priorities to meet the time critical industrial applications is proposed in this work. Latency improvements of about 40 percentage are obtained here, for slot allocations to higher priority devices, when compared with the conventional queuing methods.

scholarly journals TSCH Evaluation under Heterogeneous Mobile Scenarios

IoT ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 656-668
Author(s):  
Charalampos Orfanidis ◽  
Atis Elsts ◽  
Paul Pop ◽  
Xenofon Fafoutis
Keyword(s):  
Mobile Applications ◽  
Ieee 802.15.4 ◽  
Autonomous Robots ◽  
Industrial Applications ◽  
Mobility Patterns ◽  
Medium Access ◽  
Access Protocol ◽  
Channel Hopping ◽  
High Flexibility ◽  
Ieee 802.15.4 Standard

Time Slotted Channel Hopping (TSCH) is a medium access protocol defined in the IEEE 802.15.4 standard. It has proven to be one of the most reliable options when it comes to industrial applications. TSCH offers a degree of high flexibility and can be tailored to the requirements of specific applications. Several performance aspects of TSCH have been investigated so far, such as the energy consumption, reliability, scalability and many more. However, mobility in TSCH networks remains an aspect that has not been thoroughly explored. In this paper, we examine how TSCH performs under mobility situations. We define two mobile scenarios: one where autonomous agriculture vehicles move on a predefined trail, and a warehouse logistics scenario, where autonomous robots/vehicles and workers move randomly. We examine how different TSCH scheduling approaches perform on these mobility patterns and when a different number of nodes are operating. The results show that the current TSCH scheduling approaches are not able to handle mobile scenarios efficiently. Moreover, the results provide insights on how TSCH scheduling can be improved for mobile applications.

scholarly journals Transmission Scheduling of Periodic Real-Time Traffic in IEEE 802.15.4e TSCH-Based Industrial Mesh Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ke Shi ◽  
Lin Zhang ◽  
Zhiying Qi ◽  
Kang Tong ◽  
Hongsheng Chen
Keyword(s):  
Real Time ◽  
Mesh Networks ◽  
High Reliability ◽  
Industrial Applications ◽  
Maximum Matching ◽  
Mesh Topology ◽  
Dynamic Priority ◽  
Real Time Traffic ◽  
Channel Hopping ◽  
Ieee 802.15.4E

Time-slotted channel hopping (TSCH) is a part of an emerging IEEE 802.15.4e standard to enable deterministic low-power mesh networking, which offers high reliability and low latency for wireless industrial applications. Nonetheless, the standard only provides a framework, but it does not mandate a specific scheduling mechanism for time and frequency slot allocation. This paper focuses on a centralized scheme to schedule multiple concurrent periodic real-time flows in TSCH networks with mesh topology. In our scheme, each flow is assigned a dynamic priority based on its deadline and the hops remaining to reach the destination. A maximum matching algorithm is utilized to find conflict-free links, which provides more chances to transfer high-priority flows at each time slot. Frequency allocation is implemented by graph coloring to make finally selected links interference free. Simulation results show that our algorithm clearly outperforms the existing algorithms on the deadline satisfaction ratio with a similar radio duty cycle.

scholarly journals Evaluating IEEE 802.15.4g SUN for Dependable Low-Power Wireless Communications In Industrial Scenarios

2020 ◽  
Author(s):  
Pere Tuset-Peiró ◽  
Ruan Delgado Gomes ◽  
Pascal Thubert ◽  
Xavier Vilajosana
Keyword(s):  
Wireless Communications ◽  
Low Power ◽  
Ieee 802.15.4 ◽  
Industrial Applications ◽  
Delivery Ratio ◽  
Received Signal Strength Indicator ◽  
External Interference ◽  
Regulatory Constraints ◽  
Utility Network ◽  
Clear Channel

In this article we present a deployment of 11 nodes using the three different SUN (Smart Utility Network) modulation schemes, as defined in the IEEE 802.15.4-2015 standard. The nodes were deployed in a 110.044 m2 warehouse for 99 days, and the resulting dataset contains a total of 10.710.868 measurements with RSSI (Received Signal Strength Indicator), CCA (Clear Channel Assessment) and PDR (Packet Delivery Ratio) values. The analyzed results show a high variability in average RSSI (i.e., between -82.1 dBm and -101.7 dBm) and CCA (i.e., between -111.2 dBm and -119.9 dBm) values, which are caused by the effects of multi-path propagation and external interference. Despite being above the sensitivity limit for each modulation, this values result in poor average PDR values (i.e., from 65.9% to 87.4%), indicating that additional schemes are required for low-power wireless communications to meet the dependability requirements of industrial applications. For that purpose, we also introduce the concept of modulation diversity, which can be combined with packet repetition to meet such requirements (i.e., PDR>99%) while minimizing the energy expenditure of nodes and meeting regulatory constraints.

An Ultra-low Power Consumption MAC Protocol Complied with IEEE 802.15.4/4e for Wireless Smart Utility Networks

2016 ◽  
Vol 136 (11) ◽  
pp. 1555-1566 ◽  
Author(s):  
Jun Fujiwara ◽  
Hiroshi Harada ◽  
Takuya Kawata ◽  
Kentaro Sakamoto ◽  
Sota Tsuchiya ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
Low Power Consumption ◽  
Ultra Low Power

scholarly journals Characterizing the Impact of Doppler Effects on Body-Centric LoRa Links with SDR

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4049
Author(s):  
Thomas Ameloot ◽  
Marc Moeneclaey ◽  
Patrick Van Van Torre ◽  
Hendrik Rogier
Keyword(s):  
Wireless Communication ◽  
Low Power ◽  
Multipath Fading ◽  
Doppler Spread ◽  
Excellent Performance ◽  
Wireless Applications ◽  
Doppler Shifts ◽  
Doppler Effects ◽  
The Impact ◽  
Measurement Campaigns

Long-range, low-power wireless technologies such as LoRa have been shown to exhibit excellent performance when applied in body-centric wireless applications. However, the robustness of LoRa technology to Doppler spread has recently been called into question by a number of researchers. This paper evaluates the impact of static and dynamic Doppler shifts on a simulated LoRa symbol detector and two types of simulated LoRa receivers. The results are interpreted specifically for body-centric applications and confirm that, in most application environments, pure Doppler effects are unlikely to severely disrupt wireless communication, confirming previous research, which stated that the link deteriorations observed in a number of practical LoRa measurement campaigns would mainly be caused by multipath fading effects. Yet, dynamic Doppler shifts, which occur as a result of the relative acceleration between communicating nodes, are also shown to contribute to link degradation. This is especially so for higher LoRa spreading factors and larger packet sizes.

scholarly journals A Simulation Model of IEEE 802.15.4 GTS Mechanism and GTS Attacks in OMNeT++ / MiXiM + NETA

2018 ◽  
Vol 11 (1) ◽  
pp. 78 ◽  
Author(s):  
Yasmin M. Amin ◽  
Amr T. Abdel-Hamid
Keyword(s):  
Simulation Model ◽  
Data Transmission ◽  
Ieee 802.15.4 ◽  
Personal Area Networks ◽  
Wireless Personal Area Networks ◽  
Mac Layer ◽  
Management Scheme ◽  
Free Data ◽  
Ieee 802.15.4 Standard ◽  
Time Critical

The IEEE 802.15.4 standard defines the PHY and MAC layer specifications for Low-Rate Wireless Personal Area Networks (LR-WPANs). With the proliferation of many time-critical applications with real-time delivery, low latency, and/or specific bandwidth requirements, Guaranteed Time Slots (GTS) are increasingly being used for reliable contention-free data transmission by nodes within beacon-enabled WPANs. To evaluate the performance of the 802.15.4 GTS management scheme, this paper introduces a new GTS simulation model for OMNeT++ / MiXiM. Our GTS model considers star-topology WPANs within the 2.4 GHz frequency band, and is in full conformance with the IEEE 802.15.4 – 2006 standard. To enable thorough investigation of the behaviors and impacts of different attacks against the 802.15.4 GTS mechanism, a new GTS attacks simulation model for OMNeT++ is also introduced in this paper. Our GTS attacks model is developed for OMNeT++ / NETA, and is integrated with our GTS model to provide a single inclusive OMNeT++ simulation model for both the GTS mechanism and all known-to-date attacks against it.

A 2.4-GHz Low-Power Low-IF Receiver and Direct-Conversion Transmitter in 0.18-$\mu{\hbox {m}}$ CMOS for IEEE 802.15.4 WPAN Applications

2007 ◽  
Vol 55 (4) ◽  
pp. 682-689 ◽  
Author(s):  
Ilku Nam ◽  
Kyudon Choi ◽  
Joonhee Lee ◽  
Hyouk-Kyu Cha ◽  
Bo-Ik Seo ◽  
...  
Keyword(s):  
Low Power ◽  
Ieee 802.15.4 ◽  
Direct Conversion ◽  
Low If Receiver
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