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The recent FCC ruling has enforced database-driven cognitive radio networks (CRNs), which include white space networks in TV bands (TV band CRNs) and newly proposed small cell networks in 3.5 GHz (3.5 GHz CRNs). In database-driven CRNs, a secondary user (SU) queries the database for available spectrum at its location. However, this creates a critical vulnerability to GPS spoofing attacks. Under this...
This paper presents a strategy to choose WiFi channels in urban areas. We consider (i) inter-channel interference where adjacent channels interfere with each other in WiFi systems and (ii) urban situations where many APs in different systems are deployed in an uncoordinated way. As it is often hard to identify the channel with less interference in such a situation, we present a channel scoring function...
Recent advances in the optimal design of cross-layer congestion control, routing and scheduling algorithms allow us to calculate wireless network capacity [3]. However, for large networks, the algorithm is computationally intractable. In this paper, we provide an upper bound on the wireless network capacity that is computationally efficient to implement. Our upper bound calculations consider multiple...
In this paper the authors extend the tests and model verification related to the partially overlapped channel interference in Wi-Fi communications. Recently more and more papers have investigated the side effects of the channel interference on the throughput parameter. The paper proposes a theoretical model and an experimental approach to obtain useful information regarding channel allocation and...
As local file sharing in social network services (SNS) becomes a trend issue, the need for an efficient group communication scheme without incurring a cellular network overload is growing. The group device-to-device (GD2D) communication underlay cellular networks is a good solution for this problem. In this paper, we propose a mode selection scheme for GD2D between multicasting and cooperative relaying...
The interaction between devices sharing the same frequency domain, but using different communication protocols, is an important issue prevalent to the Internet of Things (IoT). IEEE 802.11 and IEEE 802.15.4, protocols that overlap in applications such as home automation, health care and factory automation, is one such example. In these situations 802.11 networks are known to detrimentally interfere...
For the design of dependable and efficient wireless sensor networks it is essential to estimate the achievable packet reception rate (PRR) in the deployment environment. Making such estimation is not trivial as packet delivery success depends on the level of interference present in the deployment area. In this work we show that it is possible to obtain a meaningful representation of the expected interference...
The increasing commercial success of Wi-Fi and the wireless communication industry forecast of exponential traffic growth for the next years indicate Wi-Fi dense deployments as scenarios more and more common in the future. Wi-Fi was not designed to operate in such scenarios. Because of its contention based channel access and backoff procedure, Wi-Fi presents low channel access efficiency and sensible...
A normal home environment consists of various wireless technologies, in particular WiFi and ZigBee, which usually operate in the ISM 2.4-GHz band. In addition, some of the home appliances (e.g., a microwave oven) may operate in this crowded ISM band. WiFi-based, ZigBee-based devices and home appliances operating at the same frequency and physical space can cause harmful interference to one another,...
This paper studies the capability of Long-Term Evolution-Advanced (LTE-A) together with WiFi 802.11ac to accommodate the traffic growths of 80x, 500x and 1000x in a high rise building scenario. It provides a guideline on the configuration of the spectrum and the best deployment options for the evolution of the heterogeneous network in order to enhance the capacity for the coming years. The results...
Recent progress on self-interference cancellation technology in a full-duplex system makes self-interference no longer an obstacle that restricts the system from capacity gain. In this paper, assuming both relays and access point (AP) are capable of working in full- duplex mode, we focus on to what extent a wireless relaying network can benefit from full-duplex technology. We first evaluate a conventional...
The default medium access mechanism for Wi-Fi, Distributed Coordination Function (DCF), is a simple contention based protocol aimed at providing a fair distribution of resources among Wi-Fi nodes. However, DCF suffers from significant performance degradation in the presence of dense deployments. Hence, improving the performance of the Wi-Fi MAC layer is essential for efficient spectrum sharing among...
Wireless communications suffer from disturbance and interference, which prevent reliable data exchanges and preclude their adoption in the real-time applications found at the lower levels of factory automation systems. This is particularly true for Wi-Fi, for which mechanisms like channel hopping and blacklisting are not available. Several solutions were defined in the past few years, which range...
Nowadays, Wi-Fi technology, by virtue of its unique advantages such as easier to use, faster transmission speeds and less charge, has been more widely applied. People can create a Wi-Fi hotspot with their mobile phones, laptops or other electronic equipment in any of cellular network coverage areas. But this also brings trouble to the communication networks of public transportation which work in the...
This paper evaluates the dynamic behaviour of WiFi and LTE heterogeneous network (HetNet), based on computer simulations. The basic modelling abstraction to describe system operation is described along with the necessary numerical parameters. The focus is on admission control and network reselection in HetNets; two simple but practical algorithms are described and their performance in terms of absolute...
Since wireless local area network (WLAN) can support high transmission rate with low cost, the use of WLAN is increasing rapidly. The WLAN has become very congested, and in the dense environment, Overlapping BSS (basic set service) problem may be introduced, which will severely degrade the performance of the network. Transmission power control (TPC) of AP (Access Point) is considered as one of the...
Rate adaptation algorithms (RAAs) in 802.11 networks can have a significant impact on network throughput. In order to attempt to maximize throughput, these algorithms dynamically adapt to inferred changes in the channel being used. Evaluating and comparing rate adaptation algorithms is extremely challenging due to the variability of channel conditions. Recent work on developing and evaluating new...
In this paper, we address the emerging 5G heterogeneous networks, which comprise several tiers of small cells of various sizes and by different radio access technologies. As industry has recently been targeting efficient mechanisms for tighter coordination between the tiers of such heterogeneous network, where multiple radios may be utilized simultaneously, we argue that the corresponding problem...
The first giga-bit class wireless local area network (wireless LAN) below 6 GHz frequency (the IEEE 802.11ac standard) is attracting attention due to its capability of handling much more of the rapidly growing data traffic. The increased density of wireless LAN access points (APs), however, has induced inter-cell interference that severely degrades system performance. This problem seems to be getting...
Recent years have witnessed the increasing adoption of heterogeneous wireless networks working in unlicensed ISM bands, thus creating serious problems of spectrum overcrowding. Although ZigBee, Bluetooth and WiFi networks have been natively designed for working in presence of interference, it has been observed that several performance impairments may occur because of heterogeneous sensitivity to detect...
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