This paper analyzes the impact of the No Ack policy in VoIP ad-hoc single-hop IEEE 802.11 e networks. The No Ack policy consists on suppressing the MAC layer acknowledgement packets. This option ...dramatically reduces the duration of MAC frames and thus increments the maximum number of VoIP flows that can coexist in the network. The negative side is an increased packet loss rate and the consequent drop of voice quality as perceived by the users. The article presents a model to quantify the benefits of suppressing acks and assess the viability of the No Ack policy. It follows an argumentation to identify which is the best codec to combine with acknowledgement suppression and in which conditions the usage of No Ack can be beneficial. Finally, it is suggested to modify the stations to switch to No Ack policy as the network approaches congestion.
ETSI DCC: Decentralized Congestion Control in C-ITS is a mandatory component of the 5.9 GHz ITS-G5 vehicular communication protocol stack that reduces radio channel overload, range degradation, and ...self interference. In this tutorial article we explain its principle, describe related ongoing standardization activities, evaluate its performance for emerging cooperative driving applications, and identify ways for improvement. We show that failure to use a proper DCC parameterization can impact negatively on the performance of cooperative vehicular applications.
Local governments have decided to take advantage of the presence of wireless sensor networks (WSNs) in their cities to efficiently manage several applications in their daily responsibilities. The ...enormous amount of information collected by sensor devices allows the automation of several real-time services to improve city management by using intelligent traffic-light patterns during rush hour, reducing water consumption in parks, or efficiently routing garbage collection trucks throughout the city 1. The sensor information required by these examples is mostly self-consumed by city-designed applications and managers.
Lots of hopes have been placed on machine learning (ML) as a key enabler of future wireless networks. By taking advantage of large volumes of data, ML is expected to deal with the ever-increasing ...complexity of networking problems. Unfortunately, current networks are not yet prepared to support the ensuing requirements of ML-based applications in terms of data collection, processing, and output distribution. This article points out the architectural requirements that are needed to pervasively include ML as part of future wireless networks operation. Specifically, we look into wireless local area networks (WLANs), which, due to their nature, can be found in multiple forms, ranging from cloud-based to edge-computing-like deployments. In particular, we propose to adopt the International Telecommunication Union (ITU) unified architecture for 5G and beyond. Based on ITU's architecture, we provide insights on the main requirements and the major challenges of introducing ML to the multiple modalities of WLANs. Finally, we showcase the superiority of the architecture through an ML-enabled use case for future networks.
This article discusses the design and implementation of a scalable system architecture that integrates wireless sensor networks (WSNs) into the Internet of Things (IoT) and exploits cloud services to ...autonomously configure wireless sensor nodes to measure and transmit sensed data only at periods when the environment changes more often. The implementation relies on software-defined networking (SDN) features to simplify WSN management and exploits the power of existing cloud computing platforms to execute a reinforcement learning algorithm that makes decisions based on the environment's evolution.
The following information is presented in this newletter: Advancement of Technology and Use in Managing Events and Enriching Attendee Experience: Preparing the GLOBECOM 2014 IT Infrastructure DLT/DSP ...Event, Dec. 2014, New Orleans; Highlights from the 6th International Workshop on Reliable Networks Design and Modeling (RNDM 2014); Amateur Radio Lectures In India, September 2014; 5th International FOKUS FUSECO FORUM: Smart Communications Platforms for Seamless Smart City Applications.
In this paper, we present a new ARQ protocol for the IEEE802.11a wireless LAN, based on the concept of rate-compatible punctured convolutional (RCPC) codes. The proposed protocol uses a progressive ...lower coding rate at each retransmission, based on different puncturing schemes of the 64-state convolutional code proposed in the 802.11a standard. The key idea of the new ARQ protocol is the transmission of the punctured bits at each retransmission to re-form a lower rate coded packet at the receiver side. The proposed approach improves the throughput of the 802.11a standard defined PHY/MAC modes due to a reduction in the number of retransmissions and the number of bits transmitted with each retransmission.
Objectives
To study the percentage, suppressive function and plasticity of Treg in giant cell arteritis (GCA), and the effects of glucocorticoids and tocilizumab.
Methods
Blood samples were obtained ...from 40 controls and 43 GCA patients at baseline and after treatment with glucocorticoids + IV tocilizumab (n = 20) or glucocorticoids (n = 23). Treg percentage and phenotype were assessed by flow cytometry. Suppressive function of Treg was assessed by measuring their ability to inhibit effector T‐cell (Teff) proliferation and polarisation into Th1 and Th17 cells.
Results
Treg (CD4+CD25highFoxP3+) frequency in total CD4+ T cells was decreased in active GCA patients when compared to controls (2.5% vs. 4.7%, P < 0.001) and increased after treatment with tocilizumab but worsened after treatment with glucocorticoids alone. Treg lacking exon 2 of FoxP3 were increased in GCA patients when compared to controls (23% vs. 10% of total Treg, P = 0.0096) and normalised after treatment with tocilizumab + glucocorticoids but not glucocorticoids alone. In GCA patients, Treg were unable to control Teff proliferation and induced ˜50% increase in the amount of IL‐17+ Teff, which was improved after in vitro blockade of the IL‐6 pathway by tocilizumab.
Conclusion
This study reports quantitative and functional disruptions in the regulatory immune response of GCA patients and demonstrates that, unlike glucocorticoids, tocilizumab improves Treg immune response.
In this study, we demonstrated quantitative and functional disruptions in the regulatory immune response of patients with giant cell arteritis, resulting in increased proliferation and Th17 polarization of effector T cells. In addition, our results suggest that, through a specific blockade of the IL‐6 pathway, tocilizumab associated with glucocorticoids restores a better quantitative and qualitative Treg immune response than glucocorticoids alone. GCA, giant cell arteritis. Teff, effector T‐cells; Th17, T helper‐17 cells; Treg, regulatory T‐cells.
Full text
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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