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The emergence of 5G wireless communication calls for new paradigms to satisfy the individuation and diversification of users' demands. In this paper, we construct the multicast groups under the guidance of user interest and then allocate the subcarriers and power to these groups in orthogonal frequency division multiple (OFDM) networks. Specifically, in order to maximize the social utility related...
Contention-based transmission is a promising solution for small packet traffic in the fifth generation mobile networks (5G). Packet segmentation is applied to efficiently support diverse services with relative fixed transport block (TB) setting. The packet segmentation defined by LTE RLC Unac-knowledged Mode (UM) is used in the study. First, we determine the header overhead of the segmentation. Then...
Efficiency of MAC (media access control) is one of important issues of power line communication (PLC). There exists efficiency problem in current CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism of large-scale PLC network. Aimed to solve this problem, a Cluster and Probability Competition Based MAC (CP-MAC) mechanism is presented to improve the MAC efficiency, in which the...
The Vehicular Ad Hoc Networks (VANETs), as an important part of intelligent transportation systems (ITS), has been becoming a promising research area. Due to the high mobility of vehicles and intermittent connected topology resulting in the dramatically changing network topology, it is difficult to design a protocol including congestion control mechanism, which is helpful for a well network performance...
The default mechanism for a wireless station to select which access point (AP) to associate with is based on the strength of the received signal by the station. This leads to stations associating to the closest AP. In situations where user stations are concentrated around one AP, the default algorithm (DA) results in an unbalanced distribution of station-AP associations. This causes congestion at...
The principle of attacking methods against the MAC layer of underwater acoustic network is first introduced briefly. Underwater acoustic channel characteristics are modeled corresponding Propagation Delay, Received Power and Background Noise by using OPNET pipeline stage. MAC Layer and Network Layer modules of network node are implemented. The results of a single node attack and two nodes distributed...
Ultra-dense small cell networks have been proposed as a way of addressing the explosive growth of data traffic. However, this approach often results in empty cells which only end up causing interference instead of serving UEs because they do not have any associated UEs. In this paper, we investigate the empty cell problem using system-level simulation and propose a dual layer on/off strategy for solving...
Pattern matching is an important class of problemsrelated to graphs. It is a fundamental problem for manyapplications and has been extensively studied in literature. Withthe advent of huge graphs, the challenges in this domain haveincreased manifold. Consequently a lot of recent research has ledto new architectures and approaches for optimized solutions tothe pattern matching problem. A vast majority...
In order to cope with the exponential growth of mobile traffic, mobile operators need to access more spectrum resources. LTE in unlicensed spectrum (LTE-U) has been proposed to extend the usual operation of LTE in licensed spectrum to cover also unlicensed spectrum. However, this extension poses significant challenges especially regarding the coexistence between LTE-U and legacy systems like Wi-Fi...
The increasing multimedia traffic and limited spectrum resource in Geosynchronous (GEO) satellite systems starve for an efficient Call Admission Control (CAC) scheme, which aims to provide acceptable Quality of Service (Qos) to massive users, however, the throughput may not be guaranteed. In order to maximize the total throughput of communication system, a dynamic CAC scheme, named Maximizing Throughput...
Heterogeneous networks (HetNets) are constituted by different types of base stations (eNBs), the objective of Beyond LTE does dispose more Pico eNBs to meet the traffic demand of user equipment (UE). The LTE Time Division Duplexing (TDD) system had been defined 7 uplink-downlink sub-frame configurations. For instance, two neighboring eNBs of TDD system using different uplink-downlink configuration,...
In a cognitive radio network (CRN), a premise for two nodes to communicate is having a rendezvous which means that they switch to the same channel simultaneously. Most existing channel hopping solutions for the rendezvous problem is for a homogeneous CRN where nodes have the same type of cognitive radio and thus can sense the same spectrum. In reality, nodes have different types of cognitive radios...
Eco-friendly yards, in which coal is stored in closed silos, can reduce the dust pollution in coal ports. However, the daily operation of coal ports with eco-friendly yards involves complex management strategies such as train collection strategies, storage strategies and so on, which should be studied to enhance the efficiency and cut down the cost. Thus, this paper aims to optimize the key train...
With the rapid development of WLAN, a surge in the number of network users and high-speed data exchange highlight the importance of efficient initial access of MAC layer. The majority of initial access of MAC layer is based on ALOHA or CSMA/CA. With the increase of network traffic, the number of collisions is growing rapidly, resulting in speedy decreasing access success rate and normalized throughput...
Mobile Ad hoc Network (MANET) in the form of wireless local area networks is becoming a common platform for communication among internet users. As compared with wired networks, the rate of random packet loss due to wireless channel errors or node mobility is very high in MANET. Misinterpretation of random packet loss as a loss due to congestion by TCP causes significant degradation in the performance...
The new type of the mobile Ad-hoc network, which is called Vehicular Ad-hoc Network (VANET) is creating a rich environment for research. It considered being one of the projects of the Internet of Things (IoT). IoT can be utilized in employing VANET technology to alleviate roads congestion in real time. It has a great impact on the society in general such as to reduce travel time, minimize the fuel...
Named Data Networking is a new data centric kind of communication network. This paper shows the study about NDN network and applies this architecture over Vehicular ad-hoc networks so that performance of network improves and communication becomes faster. At the end of simulation results are discussed in the form of packet delivery ratio, throughput, good put, routing overhead and various network parameters...
In this short paper, we study the deafness problem raised in the directional multi Gigabit transmission of IEEE 802.11ad standard which causes the devices to experience unequal chance of accessing the medium. We define three groups of Quasi-Omni (QO) antennas and propose two simple approaches to mitigate the deafness problem. Our simulation results show that the fairness increases up to 99% compared...
Cognitive Radio (CR) technology offers a promising solution to the spectrum scarcity problem via Dynamic Spectrum Allocation (DSA). Due to the nature of Cognitive Radio Networks (CRNs), where two networks are active simultaneously, a significant amount of control messaging is required in order to coordinate channel access, schedule sensing, and establish release connections. Efficient Control Plane...
The IEEE 802.15.4 standard for the Low Rate Wireless Personal Area Networks (LR-WPANs)is popular and widely used for many areas of applications. The standard uses slotted CSMA/CA protocol in it's contention access period (CAP) in the beacon enabled mode. The protocol adopted a Binary Exponential Backoff (BEB)algorithm. In this paper, we investigate the saturation throughput of this standard using...
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