scholarly journals Contiki-Based IEEE 802.15.4 Channel Capacity Estimation and Suitability of Its CSMA-CA MAC Layer Protocol for Real-Time Multimedia Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Omer Farooq ◽  
Thomas Kunz
Keyword(s):  
Real Time ◽  
Channel Capacity ◽  
Packet Loss ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
Multimedia Applications ◽  
Mac Layer ◽  
Medium Access ◽  
Available Bandwidth ◽  
Bandwidth Guarantees

Real-time multimedia applications require quality of service (QoS) provisioning in terms of bounds on delay and packet loss along with soft bandwidth guarantees. The shared nature of the wireless communication medium results in interference. Interference combined with the overheads, associated with a medium access control (MAC) protocol, and the implementation of a networking protocol stack limit the available bandwidth in IEEE 802.15.4-based networks and can result in congestion, even if the transmission rates of nodes are well below the maximum bandwidth supported by an underlying communication technology. Congestion degrades the performance of admitted real-time multimedia flow(s). Therefore, in this paper, we experimentally derive the IEEE 802.15.4 channel capacity using an unslotted CSMA-CA MAC protocol. We experimentally derive channel capacity for two cases, that is, when the CSMA-CA protocol is working without ACKs and when it is working with ACKs. Moreover, for both cases, we plot the relationship of offered data load with delay and packet loss rate. Simulation results demonstrate that the parameters that affect the choice of a CSMA-CA MAC layer protocol are end-to-end delay and packet loss requirements of a real-time multimedia flow, data load within the interference range of transmitters along the forwarding path, and length of the forwarding path.

scholarly journals Collision-Free Advertisement Scheduling for IEEE 802.15.4-TSCH Networks

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1789 ◽  
Author(s):  
Apostolos Karalis ◽  
Dimitrios Zorbas ◽  
Christos Douligeris
Keyword(s):  
Power Consumption ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
High Reliability ◽  
Mobile Nodes ◽  
Medium Access ◽  
Worst Case ◽  
Channel Hopping ◽  
Transmission Schedule ◽  
Scheduling Method

IEEE802.15.4-time slotted channel hopping (TSCH) is a medium access control (MAC) protocol designed to support wireless device networking, offering high reliability and low power consumption, two features that are desirable in the industrial internet of things (IIoT). The formation of an IEEE802.15.4-TSCH network relies on the periodic transmissions of network advertising frames called enhanced beacons (EB). The scheduling of EB transmissions plays a crucial role both in the joining time and in the power consumption of the nodes. The existence of collisions between EB is an important factor that negatively affects the performance. In the worst case, all the neighboring EB transmissions of a node may collide, a phenomenon which we call a full collision. Most of the EB scheduling methods that have been proposed in the literature are fully or partially based on randomness in order to create the EB transmission schedule. In this paper, we initially show that the randomness can lead to a considerable probability of collisions, and, especially, of full collisions. Subsequently, we propose a novel autonomous EB scheduling method that eliminates collisions using a simple technique that does not increase the power consumption. To the best of our knowledge, our proposed method is the first non-centralized EB scheduling method that fully eliminates collisions, and this is guaranteed even if there are mobile nodes. To evaluate our method, we compare our proposal with recent and state-of-the-art non-centralized network-advertisement scheduling methods. Our evaluation does not consider only fixed topology networks, but also networks with mobile nodes, a scenario which has not been examined before. The results of our simulations demonstrate the superiority of our method in terms of joining time and energy consumption.

scholarly journals A Mac Protocol Implementation for Wireless Sensor Network

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Jamila Bhar
Keyword(s):  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
Research Work ◽  
Packet Transmission ◽  
Area Network ◽  
Mac Layer ◽  
Good Efficiency ◽  
Protocol Implementation ◽  
Traffic Efficiency ◽  
Traffic Distribution

IEEE 802.15.4 is an important standard for Low Rate Wireless Personal Area Network (LRWPAN). The IEEE 802.15.4 presents a flexible MAC protocol that provides good efficiency for data transmission by adapting its parameters according to characteristics of different applications. In this research work, some restrictions of this standard are explained and an improvement of traffic efficiency by optimizing MAC layer is proposed. Implementation details for several blocks of communication system are carefully modeled. The protocol implementation is done using VHDL language. The analysis gives a full understanding of the behavior of the MAC protocol with regard to backoff delay, data loss probability, congestion probability, slot effectiveness, and traffic distribution for terminals. Two ideas are proposed and tested to improve efficiency of CSMA/CA mechanism for IEEE 802.15.4 MAC Layer. Primarily, we dynamically adjust the backoff exponent (BE) according to queue level of each node. Secondly, we vary the number of consecutive clear channel assessment (CCA) for packet transmission. We demonstrate also that slot compensation provided by the enhanced MAC protocol can greatly avoid unused slots. The results show the significant improvements expected by our approach among the IEEE 802.15.4 MAC standards. Synthesis results show also hardware performances of our proposed architecture.

Designing and Implementing a Lightweight WSN MAC Protocol for Smart Home Networking Applications

2016 ◽  
Vol 26 (03) ◽  
pp. 1750043 ◽  
Author(s):  
Ching-Han Chen ◽  
Ming-Yi Lin ◽  
Wen-Hung Lin
Keyword(s):  
Smart Home ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
Discrete Event ◽  
Packet Delivery Ratio ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Medium Access ◽  
Packet Delivery

Wireless sensor networks (WSNs) represent a promising solution in the fields of the Internet of Things (IoT) and machine-to-machine networks for smart home applications. However, to feasibly deploy wireless sensor devices in a smart home environment, four key requirements must be satisfied: stability, compatibility, reliability routing, and performance and power balance. In this study, we focus on the unreliability problem of the IEEE 802.15.4 WSN medium access control (MAC), which is caused by the contention-based MAC protocol used for channel access. This problem results in a low packet delivery ratio, particularly in a smart home network with only a few sensor nodes. In this paper, we first propose a lightweight WSN protocol for a smart home or an intelligent building, thus replacing the IEEE 802.15.4 protocol, which is highly complex and has a low packet delivery ratio. Subsequently, we describe the development of a discrete event system model for the WSN by using a GRAFCET and propose a development platform based on a reconfigurable FPGA for reducing fabrication cost and time. Finally, a prototype WSN controller ASIC chip without an extra CPU and with our proposed lightweight MAC was developed and tested. It enhanced the packet delivery ratio by up to 100%.

scholarly journals Secure Routing with Improved Medium Access Control (SRI-MAC) Protocol for Wireless Sensor Network using Particle Swarm Optimization

2019 ◽  
Vol 8 (5S3) ◽  
pp. 145-150
Keyword(s):  
Particle Swarm Optimization ◽  
Access Control ◽  
Medium Access Control ◽  
Sensor Node ◽  
Mac Protocol ◽  
Secure Routing ◽  
Wireless Sensor ◽  
Mac Layer ◽  
Medium Access ◽  
Swarm Optimization

A set of wireless sensor nodes comprises to form a sensor field called Wireless Sensor Networks (WSN).The main purpose of using the sensor node is to collect information from the ambience process it and send to a common gateway interface called Base Station(BS). The major problems that we face while using WSN are limited battery power, bandwidth, security issues and transmission delay etc. Many algorithms and protocols were developed in order to solve the above issues. Therefore, better solutions are required to face the improvements and challenges in the current technologies. In WSN, the sensor node highly loses its energy during communication period. One of the major issues of Medium Access Control (MAC) layer is collision. Collision increases the energy consumption and delay of the sensor node. So we have to conserve the energy of the sensor node in order to extend the lifetime of the network. At the same time it is also important to transmit the data through secure path and identify the malicious node. In this paper, we propose a novelty approach called Secure Routing with Improved Medium Access control (SRI –MAC) Protocol to solve the issues. SRIMAC identifies packet precedence sets using Fuzzy Implication System (FIS) to avoid packet collision in MAC layer and also it detects wormhole attacks and selects secure path among k-paths using Particle Swarm Optimization (PSO) algorithm. By simulation results, we show that the proposed approach is efficient in terms of energy consumption and secure routing.

scholarly journals A Call Admission Control Scheme for Multimedia Support Over IEEE 802.11 Wireless LANs

2012 ◽  
pp. 75-81
Author(s):  
Kauthale S. M.
Keyword(s):  
Real Time ◽  
Ieee 802.11 ◽  
Mac Protocol ◽  
Wireless Lans ◽  
Distributed Coordination ◽  
Channel Utilization ◽  
Time Data ◽  
Optimal Point ◽  
Available Bandwidth ◽  
Call Admission

These days there is an increasing interest for VoIP over wireless LANs. QoS support for real-time services like voice in the IEEE 802.11 WLAN is an important issue. Since IEEE 802.11 uses contention based MAC protocol – the distributed coordination function DCF, it is difficult to support the strict QoS requirements for voice in these networks. In this thesis a call admission scheme called “CAC” is proposed to achieve this goal, without changing the basic channel access mechanism of IEEE 802.11. CAC scheme regulates the arriving traffic in the wireless network to efficiently coordinate the medium among the contending traffic sources so that the network operates at optimal point, supporting the QoS requirements as well as providing better channel utilization. In this proposal, majority of available bandwidth is allocated to voice sources and remaining small amount is allocated for non real-time data traffic. It is expected that the proposed CAC scheme can well support strict QoS requirements, such as high throughput and low delay at the same time achieve a high channel utilization.

A QoS Based Formal Model for Software Defined Network

2020 ◽  
Vol 10 (3) ◽  
pp. 395-401
Author(s):  
Vivek Srivastava ◽  
Ravi Shankar Pandey
Keyword(s):  
Real Time ◽  
Channel Capacity ◽  
Packet Loss ◽  
Formal Model ◽  
Optimal Path ◽  
Network Size ◽  
Central Controller ◽  
High Traffic Volume

Background & Objective: Software-Defined Networks (SDN) decouple the responsibility of data plane, control plane and aggregates responsibilities at the controller. The controller manages all the requests generated from distributed switches to get the optimal path for sending data from source to destination using load balancing algorithms. The guarantee of packet reachability is a major challenge in real time scenario of a SDN which depends on components of network infrastructure as switches, a central controller, channel capacity and server load. The success of this aggregation and packet reachability demand is a high Quality of Service (QoS) requirement in terms of throughput, delay and packet loss due to high traffic volume and network size. This QoS has two perspectives one is required other is a computation of real QoS value. Methods: In this paper, we have presented the QoS based formal model of SDN to compute and to investigate the role of the real QoS value. This formal model includes QoS on the basis of packet movement hop by hop which is a real-time QoS. The hop by hop packet movement reliability has been computed using channel capacity and server load which is an abstraction of throughput, delay, and packet loss. The effect of channel capacity and server load can be varying using different values of the weight factor. We have also considered an equal role of channel capacity and server load to compute reliability. This QoS helps to the controller to match with required QoS to decide the better path. Conclusion: Our results finds the reliable path based on channel capacity and server load of the network. Also, results showed that the reliability of the network and controller which are based on the reliability of the packet delivery between two nodes.

Supporting Real-Time Service in Packet-Switched Wireless Networks

2011 ◽  
pp. 324-332
Author(s):  
Maode Ma
Keyword(s):  
Wireless Networks ◽  
Real Time ◽  
Mac Protocol ◽  
Critical Issue ◽  
Packet Transmission ◽  
Data Traffic ◽  
Time Data ◽  
Medium Access ◽  
Time Service ◽  
Burst Data

The requirement of providing real-time data service by wireless networks is a critical issue in the design of current wireless networks. Distributed Queueing Request Update Multiple Access (DQRUMA) has been proposed as a demand assignment medium access control (MAC) protocol to efficiently control the medium sharing by multiple mobile users. With the help of a packet transmission policy, DQRUMA has a potential to provide QoS service for the time-constrained burst data traffic. In this article, we study the problem of providing real-time service to fixed-size packets with or without time constraints in wireless networks. In particular, we propose a novel scheduling scheme for the DQRUMA protocol to control the packet transmission in packet-switched wireless networks. We have conducted extensive simulation experiments to evaluate the performance of the proposed algorithm and to compare its real-time performance with those of other packet transmission policies. This study proves that the new algorithm is an efficient transmission policy for the DQRUMA to support real-time service in wireless networks.

scholarly journals Towards Improving TSCH Energy Efficiency: An Analytical Approach to a Practical Implementation

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6047
Author(s):  
Marcos A. Sordi ◽  
Ohara K. Rayel ◽  
Guilherme L. Moritz ◽  
João L. Rebelatto
Keyword(s):  
Energy Consumption ◽  
Ieee 802.15.4 ◽  
Practical Implementation ◽  
Mac Layer ◽  
Medium Access ◽  
Energy Consumption Model ◽  
Channel Hopping ◽  
Time Scheduling ◽  
Energy Constrained ◽  
Iot Devices

The IEEE 802.15.4-2015 standard defines a number of Medium Access Control (MAC) layer protocols for low power wireless communications, which are desirable for energy-constrained Internet of Things (IoT) devices. Originally defined in the IEEE 802.15.4e amendment, the Time Slotted Channel Hopping (TSCH) has recently been attracting attention from the research community due to its reduced contention (time scheduling) and robustness against fading (channel hopping). However, it requires a certain level of synchronization between the nodes, which can increase the energy consumption. In this work, we implement the Guard Beacon (GB) strategy, aiming at reducing the guard time usually implemented to compensate for imperfect synchronization. Moreover, besides presenting a realistic energy consumption model for a Contiki Operating System-based TSCH network, we show through analytical and practical results that, without the proposed scheme, the power consumption can be more than 13% higher.

scholarly journals Reliable, Real-Time Routing in Wireless Sensor and Actuator Networks

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Martin Krogmann ◽  
Mike Heidrich ◽  
Daniel Bichler ◽  
Daniel Barisic ◽  
Guido Stromberg
Keyword(s):  
Real Time ◽  
Routing Protocol ◽  
Routing Algorithm ◽  
Multipath Routing ◽  
Wireless Sensor ◽  
Mac Layer ◽  
Routing Metric ◽  
Medium Access ◽  
Transmission Delays

We present a novel Reliable, Real-time Routing protocol (3R) based on multipath routing for highly time-constrained Wireless Sensor and Actuator Networks (WSANs). The protocol consists of a newly designed routing metric and a routing algorithm utilizing this metric. Our routing metric enables strong Quality-of-Service (QoS) support based on parallel transmissions which significantly reduces transmission delays in WSANs. A routing algorithm utilizing this metric is presented based on Dijkstra's shortest path. A novel Medium Access Control (MAC) layer that supports dynamical adjustments of retransmission limits, reduces traffic overhead in multipath routing protocols. Thorough simulations have been performed to evaluate the routing protocol, and the results show that real-time performance of WSANs can be vastly improved.

scholarly journals Channel Capacity Maximization using NQHN Approach at Heterogeneous Network

2019 ◽  
Vol 9 (4) ◽  
pp. 2593
Author(s):  
Savitha Patil ◽  
A.M. Bhavikatti
Keyword(s):  
Real Time ◽  
Channel Capacity ◽  
High Speed ◽  
Network Capacity ◽  
Small Cell ◽  
Traffic Scheduling ◽  
Coverage Area ◽  
Available Bandwidth ◽  
The Real ◽  
Wireless Communication Network

<p>In present scenario, the high speed data transmission services has pushed limits for wireless communication network capacity, at same time multimedia transmission in real-time needs provision of QoS, therefore the network capacity and small cell coverage has comes with lots of challenges. Improving the channel capacity and coverage area within the available bandwidth is necessary to provide better QoS to users, and improved channel capacity for the FCUs and MCUs in network. In this paper, we are proposing an NQHN approach that incorporate with efficient power allocation, improving the channel capacity by optimized traffic scheduling process in a small cell HetNets scenario. This work efficiently handle the interference with maintaining the user QoS and the implemented power controller uses HeNB power as per the real time based approach for macro-cell and femto-cell. Moreover, we consider the real traffic scenario to check the performance of our proposed approach with respect to existing algorithm</p>

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