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In this paper, we analyze the performance of IEEE 802.15.4e DSME-enabled wireless sensor network (WSN) and IEEE 802.15.4 beacon-enabled WSN employing slotted CSMA/CA in terms of frame error rate and aggregate throughput under the influence of IEEE 802.11b wireless LAN (WLAN) interference. The main purpose of this paper is to provide helpful information in the design of DSME-enabled WSNs in the presence...
Methods of waveguided measurements of the interference of multiple wireless transmissions are well known. In this paper a new method is shown using a well defined line-guided procedure to measure the interference between several wireless transmission systems in the same frequency range. The setup is based on wired connections in order to produce a repeatable RF channel between the DUT's. Complex structures...
In Wireless Local-Area Networks (WLANs), most of the wireless Access Points (APs) work at the full power level. So, the conflicting channels may have a significant and inevitable impact on throughput and transmission delay when the density of the APs is increasing. This paper proposes a power control algorithm, Dynamic Power Control called DPC based on NetFlow. DPC applies a fine tuning idea to get...
Due to overlapping frequency bands, IEEE 802.11a WLAN and Ultra Wide-Band systems potentially suffer from mutual interference problems. This paper proposes a method for inserting frequency notches into the IR-UWB power spectrum to ensure compatibility with WLAN systems. In contrast to conventional approaches where complicated waveform equations are used, the proposed method uses a dual-pulse frequency...
This paper proposes the deployment of frequency selective surface (FSS) structure in WLAN device. Objectives to create a band pass square-loop filter FSS in WLAN device to increase the received signal strength of WLAN signal 2.4GHz. FSS works to enhance the 2.4 GHz signal and attenuate the rest signal other than 2.4 GHz. The WLAN signals increasing more than 50 % when pass through the FSS structure.
Wireless local area network (WLAN) is the one of the technologies which enable mobile users to connect to local area network through a wireless radio connection in industrial, scientific and medical (ISM) band. Since WLAN can support high data rate communications with low-cost, the use of WLAN is rapidly increasing. However, in congested region, such as shopping mall, airport, and so on, where a lot...
The wireless hearing instruments network (WHIN) operates in the unlicensed 2.4 GHz frequency band where other wireless technologies are coexisted, and it is very crowded. The wireless binaural communication in the WHIN is most challenging due to very low power communication, and the shadowing of the human head. We propose a combined slow and fast Frequency Hopping (SFFH) scheme to select optimal transceiver...
Wireless Sensor Network (WSN) technology enables design and implementation of novel applications that can be used to address numerous industrial, environmental, social and economical challenges. The IEEE 802.15.4 standard specifies WSN as a personal unlicensed network that operates in the Industrial, Scientific and Medical (ISM) unlicensed band. Unfortunately, this band is also available for many...
This paper investigates the impact of windowing on the power allocation in cognitive radio (CR) system. The investigation shows that introducing windowing significantly improves the power allocation and transmission rate of CR as it effectively reduces interference introduced by CR system. Although the windowing technique has been widely introduced to OFDM-based systems, such as WLAN [1], its effect...
In this paper we study the problem of client association, jointly with airtime sharing and contention resolution in a multi-cell WLAN with hidden terminals with the objective of achieving proportional fair download bandwidth allocation to the clients. We first formulate the problem as a utility maximization problem, which, due to the integral nature of association turns out to be a 0–1 (NP-hard) programming...
OFDM based 802.11g Wireless Local Area Networks (WLAN) operate in the 2.4 GHz ISM band. Various other wireless systems use the same band which causes interference and leads to significant performance degradation. Hence, Cognitive Radio's (CR) could better determine free spectrum and coordinate the spectrum usage in this band. Apart from this, to reduce the interference due to spectral leakage, Filter...
A new approach for wireless local area network (WLAN) installation planning is proposed in this paper. This approach is based on a multiobjective genetic algorithm and on greedy algorithms, and it is composed of two steps: network structure design and channel assignment. In the first step, the quantity, position and load balance of the access points are planned taking into account a minimum coverage...
The number of devices equipped with IEEE 802.11 and Bluetooth technology are growing drastically, therefore interference may occur between the co-located devices in the 2.4 GHz ISM frequency band. This paper discusses the interference problem between this two co-located devices and intends to find improvement of the existing solutions for this coexisting issue. In addition to this, we consider the...
In this paper, we introduce and implement a new dynamic channel allocation scheme for Infrastructure Wireless LANs. The scheme is based on the Distributed Coordination Function (DCF) of the IEEE802.11 standard. The concept of the scheme is to dynamically distribute non-overlapping channels in the 2.4GHz band between coexisting and nearby infrastructure wireless LANs in order to solve the congestion...
In this work, we deal with the Wireless LAN planning problem. We study this problem and we propose to couple its two major issues: AP placement and channel assignment to treat them jointly. Here, we propose a novel fast and scalable three-phase heuristic algorithm (TPHA). Our proposal is able to resolve the defined multiobjective problem to provide (1) the efficient number of Access Points (APs) to...
Large-scale multi-AP WLANs with a high density of users and access points (APs) have emerged widely in various hotspots, where intra-cell interference is detrimental to the performance of WLANs. In order to mitigate the interference, a new system called cognitive WLAN over Fiber is presented in recent years. In this paper, based on Hidden Markov Modeling (HMM) detector's spectrum detection for Primary...
Real traffic replay is one of the solutions used to test network devices over complicated scenarios. Packet traces captured in a real environment hold more details than any mathematical models. However, the lack of packet-replay control and environment emulation might highly affect traffic behaviors, especially in wireless networks. Real traffic replay in wireless networks requires packet-replay control...
An important design goal for wireless local area networks (WLANs) is the performance. It is well known that the major issue challenge to the performance in WLANs is the wireless interference. This leads to an ambience that depends on the channel assignments among interfering access points (AP). Due to the limited number of non-overlapping channels, severe interference scenarios may arise if an unappropriate...
The physical layer of Wireless LAN (IEEE 802.11) supports multiple data rates and if instead of using single data rate, multiple data rates would be used then the data transmission efficiency is increased. The Rate Adaptation (RA) is such a technique adapted in Wireless LAN-802.11 to use multiple rates based on the dynamic channel condition. In this project, a new rate adaptation scheme is implemented...
In-device interference of concurrently active radios can cause significant performance degradation in small devices such as smart phones. To avoid interference-related conflicts under challenging in-device conditions, we propose a generic radio scheduling architecture to the smart phone and small but important extensions to the LTE and WLAN protocols. To LTE, we propose scheduling duration extension...
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