This paper describes an adaptive service differentiation scheme for QoS enhancement in IEEE 802.11 wireless ad-hoc networks. Our approach, called enhanced distributed coordination function (AEDCF), is derived from the new EDCF introduced upcoming 802.11e standard. aims to share transmission channel efficiently. Relative priorities are provisioned by adjusting size of contention window (CW) each traffic class taking into account both applications requirements and network conditions. We...

IEEE 802.11n is an ongoing next-generation wireless LAN standard that supports a very highspeed connection with more than 100 Mb/s data throughput measured at the medium access control layer. This article investigates key MAC enhancements help achieve high and efficiency. A detailed description given for various frame aggregation mechanisms proposed in latest draft standard. Our simulation results confirm A-MSDU, A-MPDU, combination of these methods improve extensively channel efficiency...

Two emerging technologies toward 5G wireless networks, namely non-orthogonal multiple access (NOMA) and cognitive radio (CR), will provide more efficient utilization of spectrum in the future. In this article, we investigate integration NOMA with CR into a holistic system, network, for intelligent sharing. Design principles networks are perfectly aligned to functionality requirements such as high efficiency, massive connectivity, low latency, better fairness. Three different architectures...

This article investigates the unmanned aerial vehicle (UAV)-assisted wireless powered Internet-of-Things system, where a UAV takes off from data center, flies to each of ground sensor nodes (SNs) in order transfer energy and collect SNs, then returns center. For such an optimization problem is formulated minimize average Age Information (AoI) collected all SNs. Since AoI depends on UAV's trajectory, time required for harvesting (EH) collection SN, these factors need be optimized jointly....

Wireless networks comprising unmanned aerial vehicles can offer limited connectivity in a cost-effective manner to disaster-struck regions where terrestrial infrastructure might have been damaged. While these drones advantages such as rapid deployment far-flung areas, their operations may be rendered ineffective by the absence of an adequate energy management strategy. This article considers multi-faceted applications platforms and challenges thereof future. In addition providing overview...

Non-orthogonal multiple access (NOMA) is emerging as a promising, yet challenging, technology to improve spectrum utilization for the fifth generation (5G) wireless networks. In this paper, application of NOMA multicast cognitive radio networks (termed MCR-NOMA) investigated. A dynamic cooperative MCR-NOMA scheme proposed, where secondary users serve relays performance both primary and Based on available channel state information (CSI), three different user scheduling strategies are...

MEC is an emerging paradigm that utilizes computing resources at the network edge to deploy heterogeneous applications and services. In system, mobile users enterprises can offload computation-intensive tasks nearby reduce latency save energy. When make offloading decisions, task dependency needs be considered. Due NP-hardness of problem, existing solutions are mainly heuristic, therefore have difficulties in adapting increasingly complex dynamic applications. To address challenges...

This article investigates the unmanned-aerial-vehicle (UAV)-enabled wireless powered cooperative mobile edge computing (MEC) system, where a UAV installed with an energy transmitter (ET) and MEC server provides both services to sensor devices (SDs). The active SDs desire complete their tasks assistance of neighboring idle that have no task. An optimization problem is formulated minimize total required by jointly optimizing CPU frequencies, offloading amount, transmit power, UAV's trajectory....

Fifth-generation (5G) network developers need to identify the necessary requirements toward additional capacity and spectrally efficient wireless technologies. Therefore, significant amount of underutilized spectrum in Wi-Fi band is motivating operators combine long-term evolution (LTE) with This new LTE unlicensed (LTE-U) has physical layer topology access spectrum, specifically 5-GHz band. Nevertheless, LTE-U affects operations due absence any regularity for transmissions In this article,...

To maximize the economic benefits, a cloud service provider needs to recommend its services as many users possible based on historical user-service quality data. However, when platform (e.g., Amazon) intends make recommendation decision, considering only own data is insufficient, because user may invoke from multiple distributed platforms Amazon and IBM). In this situation, it promising for collaborate with other IBM) utilize integrated improve accuracy. two challenges are present in...

This letter studies the application of non-orthogonal multiple access to a downlink cognitive radio (termed CR-NOMA) system. A new cooperative transmission scheme is proposed aimed at exploiting inherent spatial diversity offered by CR-NOMA The closed-form analytical results are developed show that gives better performance when more secondary users participate in relaying, which helps achieve maximum order user and two primary user. simulations performed validate accuracy results.

Abstract Quality‐of‐service (QoS) is a key problem of today's IP networks. Many frameworks (IntServ, DiffServ, MPLS etc.) have been proposed to provide service differentiation in the Internet. At same time, Internet becoming more and heterogeneous due recent explosion wireless In environments, bandwidth scarce channel conditions are time‐varying sometimes highly lossy. previous research works show that what well wired network cannot be directly applied environment. Although IEEE 802.11 LAN...

The IEEE 802.11 WLAN legacy standard cannot provide QoS support for multimedia applications. Thus, considerable research efforts have been carried out to enhance 802.11. Among them, 802.11e is the upcoming QoS-enhanced proposed by working group. This article describes in detail new features of based on latest version draft. We investigate performance through computer simulations. Using simple examples, we show effectiveness adaptive schemes under framework.

In upcoming very high-speed wireless LANs (WLANs), the physical (PHY) layer rate may reach 600 Mbps. To achieve high efficiency at medium access control (MAC) layer, we identify fundamental properties that must be satisfied by any CSMA-/CA-based MAC layers and develop a novel scheme called aggregation with fragment retransmission (AFR) exhibits these properties. AFR scheme, multiple packets are aggregated into transmitted in single large frame. If errors happen during transmission, only...

Abstract It is well known that the medium access control (MAC) layer main bottleneck for IEEE 802.11 wireless LANs. Much work has been done on performance analysis of MAC. However, most them assume channel error free. In this paper, we investigate saturation throughput achieved at MAC layer, in both congested and error‐prone channels. We provide a simple accurate analytical model to calculate throughput. The validated through extensive simulation results. Our results show errors have...

Multimedia stream service provided by broadband wireless networks has emerged as an important technology and attracted much attention. An all-IP network architecture with reliable high-throughput air interface makes orthogonal frequency division multiplexing access (OFDMA)-based mobile worldwide interoperability for microwave (mobile WiMAX) a viable multimedia services, such voice over IP (VoIP), TV, so on. One of the main features in WiMAX MAC layer is that it can provide'differentiated...

Vehicular ad hoc networks (VANETs) are a special form of wireless made by vehicles communicating among themselves on roads. The conventional routing protocols proposed for mobile (MANETs) work poorly in VANETs. As communication links break more frequently VANETs than MANETs, the reliability such highly dynamic needs to be paid attention. To date, very little research has focused highways. In this paper, we use evolving graph theory model VANET highway. extended helps capture characteristics...

Software-defined networking (SDN) is a key enabling technology of industrial Internet Things (IIoT) that provides dynamic reconfiguration to improve data network robustness. In the context smart grid infrastructure, strong demand seamless transmission during critical events (e.g., failures or natural disturbances) seems be fundamentally shifting energy attitude toward emerging technology. Therefore, SDN will play vital role on revolution enable flexible interfacing between utility domains...

This correspondence studies a new secrecy beamforming (SBF) scheme for multiple-input single-output non-orthogonal multiple access (MISO-NOMA) systems. In particular, the proposed SBF efficiently exploits artificial noise to protect confidential information of two NOMA assisted legitimate users, such that only eavesdropper's channel is degraded. Considering practical assumption imperfect worst-case successive interference cancellation which unique character in employing transmission, we...

This paper proposes a novel non-orthogonal multiple access (NOMA)-based cooperative transmission scheme for spectrum-sharing cognitive radio network (CRN), whereby secondary transmitter (ST) serves as relay and helps transmit the primary messages simultaneously by employing NOMA signaling. cooperation is particularly useful when ST has good channel conditions to receiver but lacks spectrum. To evaluate performance of proposed scheme, outage probability system throughput networks are derived...

Cyber-physical Internet of things system (CPIoTS), as an evolution (IoT), plays a significant role in industrial area to support the interoperability and interaction various machines (e.g., sensors, actuators, controllers) by providing seamless connectivity with low bandwidth requirement. The fifth generation (5G) is key enabling technology revolutionize future CPIoTS. In this paper, communication framework based on 5G presented deployment CPIoTS central controller. Based framework, multiple...

This paper proposes a deep hashing framework, namely, unsupervised video (UDVH), for large-scale similarity search with the aim to learn compact yet effective binary codes. Our UDVH produces hash codes in self-taught manner by jointly integrating discriminative representation optimal code learning, where an efficient alternating approach is adopted optimize objective function. The key differences from most existing methods lie in: 1) method that generates cooperatively utilizing feature...

In a public service announcement on 17 March 2016, the Federal Bureau of Investigation jointly with U.S. Department Transportation and National Highway Traffic Safety Administration (NHTSA) released warning regarding increasing vulnerability motor vehicles to remote exploits [18]. Engine shutdowns, disabled brakes, locked doors are few examples possible vehicle cybersecurity attacks. Modern cars grow into new target for cyberattacks as they become increasingly connected. While driving road,...