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A distributed system is presented for the monitoring and control of the primary variables: pressure, level and flow; for this, a wireless system is implemented at the level of sensor-actuators and at the level of controllers an Ethernet / IP network, the mentioned industrial networks are implemented based on the OSI model and TCP / IP respectively, for the visualization an HMI is realized in the software...
Named Data Networking (NDN), aka Content Centric Networking (CCN), excels in content distribution especially multimedia distribution, which can consume significant network bandwidth. With the market penetration of mobile devices and advancement of wireless technologies, media streaming over Wi-Fi becomes increasingly popular but it does not scale well in today's IP based networking. A natural question...
The exploitation of already deployed wireless local area networks (WLAN)s access points (AP)s has attracted considerable attention, as an efficient and practical method to improve the performance of wireless networks. In this paper, we adopt a hybrid accessing approach, where the WLAN APs share their wireless cellular broadband connection with other users. These users will select their serving node...
This paper presents an experimental deployment of a multi-channel wireless backbone network (WBN) with an Open Flow-based traffic management framework. In a WBN, a set of APs, each of which uses a single and different channel, is connected by Ethernet and thus constructs a VAP handling multiple channels. To flexibly control traffic flow transmitted over multiple channels, we also implement a traffic...
Nowadays, the wireless devices are equipped with multiple network interfaces to support different wireless technologies, for example, Universal Mobile Telecommunications System (UMTS), Wireless Local Area Network (WLAN), and Bluetooth etc. However, while increasing the options to connect internet via different access networks, seamless mobility cannot be assured when the wireless device is roaming...
Wireless Local Area Network (WLAN) has enabled greater communication capabilities compared to LAN counterpart. However, when it comes to quality of service (QoS), WLAN has lower reliability, where it has higher latency and packet-loss, especially for real-time streaming applications such as voice over internet protocol (VoIP) and multimedia. Thus, improving QoS in WLAN is a major research challenge,...
With the projected increase of 3G network traffic in near future, telecom operators are looking for the alternative means of satisfying the data needs of mobile subscribers without scaling the existing 3G network infrastructure. Over the last decade, IEEE 802.11 network (better called as Wi-Fi network) has emerged as one of the most competitive technology for it. It can function with the macro cellular...
Ambient networks are envisioned to be a combination of diverse but complementary access technologies. Internetworking these types of networks will provide mobile users with ubiquitous connectivity across a wide range of networking environments. The composition of existing and emerging heterogeneous wired/wireless networks requires the design of intelligent networks components to enable mobile users...
The communication based train control (CBTC) system is an advanced train control system. It uses high accuracy of train locating, realizes a continuous automatic train control system. DCS system plays an important role in the information interaction between ground equipment and vehicle equipment in CBTC. Based on OPNET simulation console, this paper designs a DCS network, simulates its communication...
Wireless Local Area Networks (WLANs) are currently among the most important technologies for wireless access. In order to exploit their full potential, wireless networks need to be planned carefully. However, chaotic unplanned Access Point (AP) placement are becoming the norm rather than an exception and causing interference among APs in the real environment. Interferences among APs often decrease...
Future generation wireless networks must support different wireless technologies, such as UMTS and WLAN. The integration of existing and emerging heterogeneous wireless networks requires the smooth integration of different networks. in the heterogeneous environment. Under Mobile IP, interconnection crossing different types of networks can be implemented in lower layers. Generally, those Mobile IP...
Within IEEE 802.11 Wireless Local Area Networks (WLANs), client stations can move freely, but because of the short range of their Access Points (APs), they usually need to reassociate with different APs to continue to communicate. When changing APs, a client station starts a process known as a handoff that can take up to 2 seconds, which is too long for real-time applications such as Voice over IP...
This paper presents a novel wireless network architecture using Radio over Free Space Optics (RoFSO) for wireless local area networks (WLANs). RoFSO not only transmits various kinds of radio services on optical wireless carrier, but also overcomes the defect of the unfeasibility of the optical fiber deployment. In addition, a RF assignment mechanism based on the wireless network architecture presented...
Transmission Control Protocol (TCP) was considered unsuitable for Low power and Lossy Networks (LLNs) due to the characteristics LLN devices (low computing power, strong energy constraint, etc.) and to the absence of IP layer on the network layer. Recently, the IPv6 over Low power Wireless Personal Area Networks (6LoWPANs) has been introduced as an adaptation layer for IPv6 over LLNs. Thanks to the...
IP reconfiguration using DHCP is the usual approach followed by mobile nodes (MNs) when they roam from one network to another one. However, DHCP is too slow for cooping with fast handover requirements. This article describes a cross-layer approach for accelerating DHCP-based IP reconfigurations in a mobility scenario across 802.11 access points (APs). DHCP transactions are initiated by neighboring...
In this paper, we propose a QoS control mechanism that estimates the congestion of wireless channels in the wireless LAN and evaluates the voice packet drop ratio based on the estimated congestion status. The mechanism adjusts the voice packet transmission rate according to the evaluated packet loss ratio, and thereby resolves the congestion situation. In this way, the mechanism can keep users' quality...
Privacy issues have been a serious concern for 802.11 Wireless LAN users. As demonstrated by Pang et al. and Xu et al., applying pseudonym techniques does not completely protect users' privacy. In particular, users' identities can be disclosed through implicit identifiers such as the IP addresses and port numbers users often access. In this paper, we study how to improve user anonymity even if implicit...
Rogue wireless access points (RWAPs) bypass physical endpoint security of local area networks and present significant security threats by creating network attack vectors behind firewalls, exposing confidential information, and allowing unauthorized utilization of network resources. A family of more promising methods detects RWAPs indirectly by identifying unauthorized wireless hosts through using...
Safety information of evacuees is the most important information for relief activities in disasters. We have discussed about required conditions for computer systems destined for supporting effective relief activities after disasters. In addition, on the basis of this discussion, we also have proposed a network construction algorithm and have performed preliminary evaluation about the installation...
Voice over Internet Protocol (VoIP) over a wireless local area network (WLAN) is poised to become an important Internet application. However, unacceptable VoIP performance in the presence of coexisting traffic from other applications is still one of the major problems standing in its development way. For this point, in this paper, a novel adapted adjustment packet segmentation method is proposed to...
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