Effect of service differentiation on QoS in IEEE 802.11e enhanced distributed channel access: a simulation approach

The enhanced distributed channel access (EDCA) protocol is a supplement to IEEE 802.11 medium access control (MAC), ratified by IEEE 802.11e task group to support quality of service (QoS) requirements of both data and real-time applications. Previous research show that it supports priority scheme for multimedia traffic but strict QoS is not guaranteed. This can be attributed to inappropriate tuning of the medium access parameters. Thus, an in-depth analysis of the EDCA protocol and ways of tuning medium access parameters to improve QoS requirements for multimedia traffic is presented in this work. An EDCA model was developed and simulated using MATLAB to assess the effect of differentiating contention window (CW) and arbitration inter-frame space (AIFS) of different traffic on QoS parameters. The optimal performance, delay, and maximum sustainable throughput for each traffic type were computed under saturation load. Insight shows that traffic with higher priority values acquired most of the available channels and starved traffic with lower priority values. The AIFS has more influence on the QoS of EDCA protocol. It was also observed that small CW values generate higher packet drops and collision rate probability. Thus, EDCA protocol provides mechanism for service differentiation which strongly depends on channel access parameters: CW sizes and AIFS.

METHODOLOGY FOR ASSESSING THE EFFECTIVENESS OF METHODS FOR EMBEDDING DIGITAL WATERMARKS

In recent years, we have seen a significant increase in traffic moving across various networks and channels. The development of technology and global network leads to an increase in the amount of multimedia traffic. To authenticate and avoid abuse, data should be protected with watermarks. This paper discusses various robust and invisible watermarking methods in the spatial domain and the transform domain. The basic concepts of digital watermarks, important characteristics and areas of application of watermarks are considered in detail. The paper also presents the most important criteria for assessing the digital watermark effectiveness. Based on the analysis of the current state of the digital watermarking methods, robustness, imperceptibility, security and payload have been determined as the main factors in most scientific works. Moreover, researchers use different methods to improve / balance these factors to create an effective watermarking system. Our research identified the main factors and new techniques used in modern research. And the assessment of watermark method effectiveness was proposed.

A Survey on Visible Light Communication Standards

With the rapid increase of high-fidelity audio, video, and multimedia traffic in the new era of 5G and beyond, the current Wi-Fi solution exhibits more and more limitations. Crowded spectrum is creating realistic bottlenecks in the deployment of Wi-Fi, some of which can be well alleviated by the Light Fidelity (Li-Fi) technology. High transmission rate, wide bandwidth, no electromagnetic interference, and no health hazards have made Li-Fi an attractive technique for future smallcell communication. The emerging standardization of visible light communication (VLC) facilitates the acceleration of the development of Li-Fi technology and will eventually deliver real-world Li-Fi deployments. This article overviews the recent progress on VLC standardization and presents the mainstream VLC standards created by different standardization organizations.

MASEMUL: A Simulation Tool for Movement-Aware MANET Scheduling Strategies for Multimedia Communications

The last decade has witnessed a steep growth in multimedia traffic due to real-time content delivery such as in online games and video conferencing. In some contexts, MANETs play a key role in the hyperconnectivity of everything in multimedia services. In this context, this work proposes a new scheduling approach based on context-aware mobile nodes for their connectivity. The contribution relies on reporting not only the locations of devices in the network but also their movement identified by sensors. In order to illustrate this approach, we have developed a novel agent-based simulator called MASEMUL for illustrating the proposed approach. The results show that a movement-aware scheduling strategy defined with the proposed approach has decreased the ratio of channel interruptions over another common strategy in mobile networks.

Crowdsourcing Framework for QoE-Aware SD-WAN

The exponential increase in bandwidth-sensitive multimedia traffic on the Internet has created new challenges and opportunities. With the shifting focus from service availability to service quality, there is a need to have quality management measures to serve the high needs of efficient transmission and delivery in time-constrained environments over IP networks. Quality of Experience (QoE) is now considered the most important measure to achieve the twin goals of application efficiency and user satisfaction from a user perspective. In this paper, we propose a framework that can be used to collect real-time QoE feedback through crowdsourcing and forward it to SD-WAN controllers to enhance streaming routes based on real-time user quality perceptions. We analyze how QoE can be affected by different network conditions, and how different streaming protocols compare against each other when the network parameters change dynamically. We compare the real-time user feedback to predefined network changes to measure if participants will be able to identify all degradation events, and to examine which combination of degradation events are noticeable to the participants. These QoE timestamped feedback is sent back to the SD-WAN controller continuously in order to locate problems and bottlenecks in the current service paths and to enable network controllers to take corrective action by rerouting the streamed traffic. Our aim is to demonstrate that real-time QoE feedback can enhance cloud-based services and can adjust services quality based on real-time, active participants’ interaction[1].[1] This paper extends the preliminary results presented by the authors at the PVE-SDN 2019 workshop in IEEE Conference on Network Softwarization (NetSoft 2019).