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The IEEE 802.11 protocols are used by millions of smartphone and tablet devices to access the Internet via Wi-Fi wireless networks or communicate with one another directly in a peer-to-peer mode. Insider attacks are those originating from a trusted node that had initially passed all the authentication steps to access the network and then got compromised. A trusted node that has turned rogue can easily...
Multi-Channel Wi-Fi experiments are quickly becoming more common and relevant as Wi-Fi deployments have become extremely popular and dense in recent years. There are many simulation tools available for Wi-Fi simulation, but few are widely used, and some are not designed specifically with wireless in mind. In this paper, the NS3 environment is recognized as a promising tool for which for this type...
We describe performance results for a Dynamic Spectrum Management (DSM) Platform, including over-the-air data captured outdoors near our Melville, NY facility and in an indoor office environment. The DSM system configuration used to generate the results, and the flexibility of the DSM system that allows it to operate in different bandwidth TV channels are presented. The results include data throughput,...
The IEEE 802.11 standardization group has recently ratified 802.11ac as the newest major amendment of the 802.11 family of Wi-Fi standards. While 802.11ac has specified a number of improvements over 802.11n such as: (i) 8 spatial streams (ii) mandatory bandwidth of 80 MHz and (iii) multi-user MIMO on the downlink, these improvements mostly target to improve the per-link throughput, and in case of...
In future's high density Wireless Local Area Networks (WLANs), to improve the overall throughput, we envision the optimization of the MAC protocols and mechanisms. Traditionally, it's clear in the literature that Transmit Power Control (TPC) is chosen as one of the most powerful tools for optimizing MAC protocols. However, the TPC is not always possible to implement due to hardware and licensing limitations...
IEEE 802.11 standard primarily utilizes Distributed Coordination Function (DCF) which is based on carrier sense multiple access with collision avoidance (CSMA/CA). IN DCF, when a collision occurs, then a backoff algorithm will take place to randomize medium access for the nodes. The default backoff mechanism used in 802.11 is the binary exponential backoff (BEB) algorithm. In this paper, we analyze...
Generating a busy tone is known as a good solution that enables a ZigBee network to coexist with any Wi-Fi network in the same ISM band. To generate a busy tone, ZigBee networks need to deploy a signaler that transmits it with the same power as Wi-Fi nodes, thus preventing other Wi-Fi nodes from accessing the corresponding channel. In this paper, we mathematically analyze the delivery ratio and delay...
Wireless LANs based on the IEEE 802.11 standard are one of the most commonplace indoor wireless access solutions. As the ever growing demand for data consumption necessitates higher rates and volumes, it is fairly common to observe more and more WLANs being deployed in close proximity to each other. As distances between WLAN installations diminish, the access points (APs) and stations (STAs) in these...
The increased density of wireless local area network (wireless LAN) access points (APs) based on the IEEE 802.11 standard has induced inter-cell interference that severely degrades system performance. In order to mitigate this issue, this paper proposes an efficient network-controlled channel allocation scheme that can be applied to a managed wireless LAN system with a central coordinator. On the...
Since communications services become much more demanded after disaster strikes, it is necessary to promptly set up a temporary communications infrastructure to provide services to those in need. The Movable and Deployable Resource Unit (MDRU) based Wireless Mesh Network (WMN) is an attractive candidate to achieving this goal. In MDRU based WMN, the MDRU is transported to the disaster affected area...
In this paper, we present a new Wi-Fi roaming and selection scheme as a solution for macro-cell traffic offloading. The idea is to take advantage of the Access Network Discovery and Selection Function (ANDSF) policies and the IEEE 802.11k standard for Wi-Fi access point (AP) selection process. The ANDSF can provide the list of candidate APs with preferred selection policies. However, due to the fact...
The extensive use of IEEE 802.11 WLAN networks have taken a tremendous leap in the area of wireless communication. Its increasing PHY data rate is at par with the wired Ethernet. However, at Medium Access Control (MAC) layer, the protocol lacks to utilize its full efficiency. The IEEE 802.11 Distributed Coordination channel access Function (DCF), is still based on contention-based random channel access...
We study the resource allocation and management issues related to heterogeneous wireless systems made up of several Radio Access Technologies (RATs) that collectively provide a unified wireless network to a diverse set of users through co-ordination managed by a centralized Global Resource Controller (GRC). We assume that the user devices are multi-modal, which makes it possible for each device to...
Heterogeneous networks are expected to play a major role towards meeting the exploding traffic demand over cellular systems. Particularly, existing WiFi hotspots will be dynamically utilized to offload the traffic of cellular mobile subscribers. This will be further facilitated by forthcoming advances in mobile device capabilities that will include the ability to operate multiple wireless interfaces...
Dynamic transmit-power control (DTPC) is critical to improve spectral efficiency and reduce interference in wireless local area networks (WLANs). DTPC schemes typically use signal-to-noise-ratio (SNR) information and require exchange of information between transmitters and receivers. However, that is not always easy to implement in actual WLAN deployments. In this paper, we present a simple but novel...
In a distributed control wireless ad-hoc network, network performance is significantly effected by multi-user interference. In such networks, transmit power control can enhance the energy usage as well as the QoS performance. Although, the effects of hidden/exposed terminals on the system throughput in wireless ad-hoc networks have been studied extensively, the IEEE 802.11 with variable transmit power...
We investigate the effectiveness of the 3GPP offloading policy framework, called Access Network Discovery Selection Function (ANDSF). We consider geographical areas where both LTE and WiFi are available and present a model describing multi-RAT networks as visible by the operator, as well as the offloading policy rules that apply to them. Our model captures user behavior and allows us to express any...
Frequently, client-side wireless devices have a view of multiple WiFi access points, whether from open residential and commercial networks, corporate networks, or mesh networks. Given the increasing number of radios and antennas in today's wireless devices, residual capacity from these multiple APs could be leveraged if client devices communicate with multiple APs simultaneously. In this paper, we...
Co-existing in the unlicensed ISM band, ZigBee transmissions can be significantly interfered by WiFi. Although several approaches recently are proposed to enable ZigBee transmission under WiFi interference, the ZigBee throughput still decreases to zero when WiFi throughput (generated by D-ITG) is over 8Mbps. In this paper, we propose a real-time (< 5ms) adaptive transmission (RAT) scheme to efficiently...
This demo presents a novel multirate multicast scheme for video delivery to wireless users. We demonstrate an adaptive scheme that combines differential backlog scheduling and intelligent packet dropping, both based on local information. An important feature of this scheme is that it does not require centralized calculations. We focus on 802.11 mesh networks and we show that our solution copes efficiently...
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