MAC Layer Performance Research Articles

A Collision Reduction Adaptive Data Rate Algorithm Based on the FSVM for a Low-Cost LoRa Gateway

LoRa (Long Range), a wireless communication technology for low power wide area networks (LPWANs), enables a wide range of IoT applications and inter-device communication, due to its openness and flexible network deployment. In the actual deployment and operation of LoRa networks, the static link transmission scheme does not make full use of the channel resources in the time-varying channel environment, resulting in a poor network performance. In this paper, we propose a more effective adaptive data rate (ADR) algorithm for low-cost gateways, we firstly analyze the impact of the different hardware parameters (RSSI, SNR) on the link quality and classify the link quality using the fuzzy support vector machine (FSVM). Secondly, we establish an end device (ED) throughput model and energy consumption model and design different adaptive rate algorithms, according to the different link quality considering both the link-level performance and the MAC layer performance. The proposed algorithm uses machine learning to classify the link quality, which can accurately classify the link quality using a small amount of data, compared to other adaptive rate algorithms, and the link parameter adaptation algorithm can maximize the throughput while ensuring the link stability, by considering the link-level performance and the MAC layer performance, compared to other algorithms. The results show that it outperforms the standard LoRaWAN ADR algorithm in both the single ED and the multi ED scenarios, in terms of the packets reception rate (PRR) and the network throughput. Compared to the LoRaWAN ADR in 32 multi-ED scenarios, the proposed algorithm improves the throughput by 34.12% and packets the reception rate by 26%, significantly improving the network throughput and the packets reception rate.

Revisiting the IEEE 802.11n A-MPDU Retransmission Scheme

The aggregate MAC protocol data unit (A-MPDU) and Block Acknowledgment (Block Ack) techniques are among the pivotal MAC layer enhancements introduced by the IEEE 802.11n amendment. Although they have been studied extensively in the literature, recent research studies have proven that the existing analytical models proposed for those techniques are not conform to 802.11n standard specifications, since they do not capture the effect of the Block Ack window limit on the aggregation size which provokes critical errors in the estimation of 802.11n MAC layer performance. In this letter, we elaborate a new analytical model compliant with the conventional A-MPDU retransmission scheme to conduct an accurate analysis of the performance of A-MPDU and Block Ack techniques under different network conditions. To validate the accuracy of our model, we compared the numerical results to those obtained using ns-3 simulator and with two other analytical models investigating the performance of 802.11n MAC layer.

Impact of Buffer Management Solutions on MAC Layer Performance in Wireless Sensor Networks

Impact of Buffer Management Solutions on MAC Layer Performance in Wireless Sensor Networks

Analysis of Latency and MAC-Layer Performance for Class A LoRaWAN

We propose analytical models that allow us to investigate the performance of long range wide area network (LoRaWAN) uplink in terms of latency, collision rate, and throughput under the constraints of the regulatory duty cycling, when assuming exponential inter-arrival times. Our models take into account sub-band selection and the case of sub-band combining. Our numerical evaluations consider specifically the European ISM band, but the analysis is applicable to any coherent band. Protocol simulations are used to validate the proposed models. We find that sub-band selection and combining have a large effect on the quality of service (QoS) experienced in an LoRaWAN cell for a given load. The proposed models allow for the optimization of resource allocation within a cell given a set of QoS requirements and a traffic model.

Delay, Reliability, and Throughput Based QoS Profile: A MAC Layer Performance Optimization Mechanism for Biomedical Applications in Wireless Body Area Sensor Networks

Recently, increasing demand for remote healthcare monitoring systems poses a specific set of Quality of Services (QoS) requirements to the MAC layer protocols and standards (IEEE 802.15.6, IEEE 802.15.4, etc.) of Wireless Body Area Sensor Networks (WBASNs). They mainly include time bounded services (latency), reliable data transmission, fair channel distribution, and specified data rates. The existing MAC protocols of WBASNs are lack of a specific set of QoS. To address this, the paper proposes a QoS profile named delay, reliability, and throughput (DRT). The QoS values computed through DRT profile provide maximum reliability of data transmission within an acceptable latency and data rates. The DRT is based on the carrier sense multiple access with collision avoidance (CSMA/CA) channel access mechanism and considers IEEE 802.15.4 (low-rate WPAN) and IEEE 802.15.6 (WBASN). Further, a detailed performance analysis of different frequency bands is done which are standardized for WBASNs, that is, 420 MHz, 868 MHz, 2.4 GHz, and so forth. Finally, a series of experiments are conducted to produce statistical results for DRT profile with respect to delay, reliability, and packet delivery ratio (PDR). The calculated results are verified through extensive simulations in the CASTALIA 3.2 framework using the OMNET++ network simulator.

Design a New Bidirectional Transmission Protocol to Improve the Performance of MAC Layer Based on Very High Speed WLANs

This paper presents a new bidirectional transmission protocol with single data frame to computing the performance of MAC layer based on IEEE 802.11n. As high as 600 Mbps of physical data rate is achieved in IEEE 802.11n where high data rate the current MAC layer leads to high performance overhead and low performance of throughput and designing the MAC layer still ongoing to achieve high performance throughput. In this study, a new bidirectional transmission protocol with single data frame has been proposed called BTDF bidirectional transmission data fragmentation, which is divided each data frame from sender to receiver and reverse into subframes and send each subframe, Packets those exceed the size threshold are divided into fragments also where the corrupted subframe will be retransmitted during the disruption of transmission. We have implemented this scheme in NS2 simulator to show the results for TCP and HDTV traffics and compared with literature.

Modelling of IEEE 802.11 DCF in the presence of hidden nodes

Today, the most commonly used technology for wireless networks is IEEE 802.11. The performance of the Medium Access Control MAC layer, which consists of Distributed Coordination Function DCF and Point Coordination Function PCF, has been examined over a long time period. The DCF is the random access scheme that uses CSMA/CA in IEEE 802.11 MAC layer protocol. There are various issues related to the performance evaluation of IEEE 802.11 DCF and one of the important issues is the problem of hidden terminals which exists in practice in any wireless network. In this paper, a two-dimensional analytical model is proposed for the analysis of IEEE 802.11 DCF in the presence of hidden terminals for both basic access and RTS/CTS modes by making use of the Markov chain.

Smart-device-to-smart-device communications: Part 2 [Guest Editorial

As telecom operators are struggling to accommodate the existing demands of mobile users, new data consuming applications are emerging in the daily routines of mobile users (e.g., proximity-aware services). Moreover, 4G cellular technologies (WiMAX and LTE-A), which have extremely efficient physical and MAC layer performance, are still lagging behind mobile users' booming data demand. One of the most promising approaches to boost mobile capacity is to reuse efficiently existing frequency bands. This can be accomplished by several options, such as densification of the base stations and deployment of small cells underlying the conventional cellular networks, and using cognitive radio and spectrum sharing. Device to-device (D2D) communication is one such paradigm that appears to be a promising component in the next generation cellular technologies. In fact, a Third Generation Partnership Project (3GPP) study group is investigating D2D communications in cellular networks.

Smart-device-to-smart-device communications: part I [Guest editorial

As telecom operators are struggling to accommodate the existing demands of mobile users, new data consuming applications are emerging in the daily routines of mobile users (e.g., proximity-aware services). Moreover, 4G cellular technologies (WiMAX and LTE-A), which have extremely efficient physical and MAC layer performance, are still lagging behind mobile users' booming data demand. One of the most promising approaches to boost mobile capacity is to reuse efficiently existing frequency bands. This can be accomplished by several options, such as densification of the base stations and deployment of small cells underlying the conventional cellular networks, and using cognitive radio and spectrum sharing. Device to-device (D2D) communication is one such paradigm that appears to be a promising component in the next generation cellular technologies. In fact, a Third Generation Partnership Project (3GPP) study group is investigating D2D communications in cellular networks.

Analysis of scalability for AODV routing protocol in wireless sensor networks

This paper presents preliminary work to address scalability concern over AODV protocol in wireless sensor network. Firstly, we discussed the scalability design issues with related work in context of wireless sensor networks (WSN). Following, we designed and illustrated wireless sensor network model. Finally, significance of scalability on the behaviour of application, MAC, transport and physical layer performance is described.

Impact of Cognition and Cooperation on MAC Layer Performance Metrics, Part I: Maximum Stable Throughput

In this paper, we consider a broadband secondary transmitter-receiver pair which interferes with N narrowband primary users and study the effect of cognition and cooperation on the maximum stable throughput. In our study we focus on four transmission protocols as well as two channel types, i.e., flat fading and frequency selective fading. In the cooperative protocols, the broadband transmitter relays the packets of the primary users which have not correctly decoded at the primary receiver. The analysis includes random packet arrivals at the transmitters which may impact on the maximum stable throughput. Moreover, sensing errors at the secondary user are considered. In this paper, we derive the exact stability region for non-cooperative protocols and inner bounds for cooperative ones. The results reveal that depending on the channel states, the cooperative protocols may provide significant performance gains over non-cooperative protocols. Numerical results indicate that in the frequency selective channel, independent and simultaneous parallel transmissions in the available subbands are preferred, while in the flat fading channel, a non-parallel transmission in the total available bandwidth is recommended. In part II of our paper, we investigate the impact of cognition and cooperation on the delay performance of the protocols introduced in this paper.

MAC-Layer Performance Enhancement Using Control Packet Buffering in Optical Burst-Switched Networks

One of the major hurdles in optical burst-switched (OBS) networks is the contention problem. In this paper, we tackle this problem by proposing a new contention resolution technique based on control packet buffering. In particular, a rigorous mathematical model is developed to analyze the performance of an OBS network core node employing this technique along with just-in- time one-way reservation protocol. The key idea that makes this proposal novel is that this buffering is implemented in the electronic domain, thus avoiding the complexity that exist in the optical domain solutions. A detailed evaluation of the system performance using both the burst loss probability and the steady-state throughput is presented. Our results reveal that a considerable improvement in the performance is achieved when adopting the proposed technique.

Emulation of multipath effects on a wireless testbed and its impact on MAC layer performance

Field experiments are an important part of research in wireless networks. Since the wireless channel varies with location and time, the results vary for the same field experiment at a different place and time. Assumptions about the wireless environment can lead to biased results. It is necessary to shield wireless transmission from uncontrolled interference in order to make the experiment repeatable. This paper describes $$\underline{A}$$ dvanced wirele $$\underline{SS}$$ $$\underline{E}$$ nvironment $$\underline{R}$$ esearch $$\underline{T}$$ estbed (ASSERT) which uses shielded co-axial cables as the communication media for radio signals to conduct reliable, scalable and accurate wireless experiments. Shielding the transmission also protects the signal from random burst of noise introduced by the environment. The paper describes how the combination of programmable attenuators and RF splitters/combiners, which are part of ASSERT, helps in emulating complex and varying environments including those in which multipath interference plays a significant role. Our experimental results indicate that (1) tweaking the MAC layer and retransmissions at the application layer neutralize, to an extent, the impact of multipath effects when the received signal strength is extremely good, and (2) when the received signal strength falls below a certain threshold multipath interference plays a significant role.

MAC Layer Performance: Study and Analysis for Different Mobility Conditions in WSN

Wireless sensor networks are the most challenging networks for communication because of its resource constrained nature and the dynamical nature of network topographic anatomy. A lot of research is being going on in the diverse parts of the world for optimum utilization of communication resources in these special types of ad hoc networks. The utility and application domain of sensor networks ranges from commercial, public safety applications and military sector to be the most important ones. The magnificent challenges to the routing algorithms employed in such type of networks are due to the mercurial size of the network and its expandable topology that is quite dynamic in nature. The present paper offers a comparison and analysis of the packet drop at the MAC layer for different routing protocols under an experimental setup having different mobility condition based scenarios of the wireless sensor network application. The comparative study may have also an impact on the improvement of MAC layer performance for different simulation times of the experimental setup considering two of reactive as well as proactive protocols that are most widely used routing protocol in wireless sensor networks. Wireless sensor network application under consideration for the experimental is the battle field monitoring wireless sensor network and the comparative study has been performed for four different mobility patterns described as four different scenarios in the considered experimental application of wireless sensor networks. The sensor network simulative electronic deception architecture used is for the battle field monitoring application of wireless sensor networks. The application provides support for sensing capabilities within the network nodes called as UGS (Unattended Ground Sensors).Mobile nodes gather data from battle field and direct it to the base station via mobile UGV (Unmanned Ground Vehicles).The performance of the MAC Layer varies with the different average jitter values for different simulation times in the network. Power usage model has been used to reliably represent an actual sensor hardware and sensor network oriented traffic pattern.

A Cross-Layer Adaptive Modulation and Coding Scheme for Energy Efficient Software Defined Radio

In this paper, a simple and novel cross-layer adaptive modulation and coding (AMC) scheme, which increases the energy efficiency of the wireless communication system is proposed. Traditionally, AMC has been used to improve MAC-layer performance in terms of coded bit error rate, packet error rate, and throughput. The modulation and coding scheme is switched according to signal-to-noise ratio thresholds at the PHY layer. We extend the approach, proposing a framework for energy-efficient cross-layer AMC that captures the impact of both MAC layer and PHY layer parameters on the AMC switching criteria. Cross-layer designs are naturally suited to software defined radio applications. Not only are they readily implemented in software, but also they are integral to the radio components. They can optimize performance of the radio either for a given configuration or adaptively. Through examples of WLAN physical layer and Frequency Domain Equalized systems, we demonstrate our AMC scheme and verify its effectiveness by simulation.

MAC Layer Throughput Estimation in Impulse-Radio UWB Networks

The inherent channel characteristics of impulse-based UWB networks affect the MAC layer performance significantly. Most previous studies on evaluating MAC protocols are based on prolonged simulations and do not account for the multiple access interference due to multipath delay spread. In this work, we develop CTU, an analytical framework for Capturing the Throughput dependencies in UWB networks, while taking into account the PHY layer effects. The key attributes of CTU are: 1) It is modular; it can be easily modified to provide a basis for evaluating a wide range of MAC protocols for impulse-based UWB networks. The only requirements are that the MAC protocol under study be based on time-hopping and the modulation scheme be pulse position modulation; these are common design decisions in UWB networks. 2) It considers the channel characteristics in addition to MAC layer effects; CTU correlates probabilistically the multipath delay profile of the channel with the packet error rate. We employ CTU to evaluate the performance of different generic medium access procedure. We compare the results with those from extensive simulations and show the high accuracy of CTU. We use CTU to assess the impact of various system parameters on the MAC layer performance; we make several interesting observations that are discussed in depth.

WiseNET: an ultralow-power wireless sensor network solution

A wireless sensor network consists of many energy-autonomous microsensors distributed throughout an area of interest. Each node monitors its local environment, locally processing and storing the collected data so that other nodes can use it. To optimize power consumption, the Swiss Center for Electronics and Microtechnology has developed WiseNET, an ultralow-power platform for the implementation of wireless sensor networks that achieves low-power operation through a careful codesign approach. The WiseNET platform uses a codesign approach that combines a dedicated duty-cycled radio with WiseMAC, a low-power media access control protocol, and a complex system-on-chip sensor node to exploit the intimate relationship between MAC-layer performance and radio transceiver parameters. The WiseNET solution consumes about 100 times less power than comparable solutions.