Knowledge Base

Title Authors Last Update Category
A Comparison of Efficiency, Throughput, and Energy Requirements of Wireless Anthony Murabito

As energy sources are dwindling, power consumption is a major obstacle facing virtually every industry. Alongside Internet access, wireless computer networks, more commonly known as Wi-Fi networks, have become widely adopted. These wireless networks have found their way into our homes and have also spread to the enterprise market. The goal of this research is to study the power consumption of wireless Access Points, and determine possible means to reduce the energy requirement of the Access Point.

March 1, 2009 White Papers
Performance Evaluation of TCP over IEEE 802.11 WLANs Sachin Goel

Transmission Control Protocol (TCP) is a communication protocol that is used to provide reliable data delivery between hosts. As TCP is the most highly used transport-layer protocol, many have worked on addressing the issue of performance. Performance issues have been studied in various environments, especially when using 802.11 Wireless Local Area Networks (WLANs). Wireless networks are prone to a higher number of packets loss and corruption. 802.11 WLANs have an equivalently fast acknowledgement mechanism as TCP to ensure reliability of traffic over it. This duplication of functionality between TCP and 802.11 WLAN creates unexpected behaviors that can result in high costs in terms of overall performance. A significant amount of analytical and simulation work has been done in the past to study the behaviour of TCP over 802.11 WLANs. The main contribution of this work is the analysis of TCP interaction in an 802.11 WLAN topology by using real commercial-grade equipments. A testing methodology is designed to do the quantitative performance evaluation in a network topology consisted of wired as well as a wireless connection. The methodology contains test scenarios with different configurable settings on an Access Point (AP) and various controlled impairments in the network topology such as latency, packet drop, noise interference, etc. The performance of TCP is measured in terms of the throughput. This work provides a comprehensive set of experiments to study the behaviour of TCP over 802.11 WLANs. The results can provide insight into the performance cost associated with TCP traffic on 802.11 WLANs under different network environments and configurations on the AP. The results of this work thus have a value to equipment manufacturers and network operators.

September 1, 2006 Theses
Comparison of Environments on 802.11 Throughput Performance Diana Lewis, Justin Rebe, Jeremy deVries

The chaotic nature of the radio frequency medium of 802.11 wireless networks makes it problematic to obtain accurate and precise repetition of performance tests and measurements. Environmental variables that deeply influence link performance must be addressed before throughput testing can be accurately measured across various devices. An RF shielded room with anechoic foam provides the most ideal environment for throughput tests compared to either an RF shielded room without foam or an open air laboratory. Location within the RF shielded room with anechoic foam was shown to have a negligible effect on performance, but using an RF absorbing rubber mat under a device was shown to reduce reflections, producing an optimal environment for throughput testing.

September 18, 2014 White Papers
Wireless Networking Overview Kevin Karcz, Jeremy Kent

An overview of various wireless networking technologies, their relationship to one another, and a look at emerging standards.

September 18, 2014 Tutorials
WPA-PSK: Step-by-Step Jeremy deVries

In today's age of ubiquitous SOHO networks and ever more Wi-Fi in laptops, security is a paramount concern. Unsecured or improperly set up wireless networks can leave you vulnerable to intrusion, viruses, hijacking of bandwidth, and more problems than one can list, which is why properly setting up your secured network using an authentication mechanism such as WPA-PSK is a crucial step in creating a wireless network. This article provides an overview of the Wi-Fi Protected Access Pre-Shared Key (WPA-PSK) security mechanism, and a step-by-step guide to securing your wireless network.

September 30, 2005 Tutorials
IEEE 802.11 Working Group for WLAN Standards IEEE LMSC

IEEE P802.11 is a standards working group on wireless local area networks. The working group is a part of IEEE LMSC (LAN MAN Standards Committee) formerly called IEEE Project 802. IEEE LMSC reports to the Standards Activity Board (SAB) of the IEEE Computer Society.

June 1, 2005 External Links
Voice Over IP and Wireless Data Coexistence in a WLAN Switch Deployment Tom Leary, UNH-IOL; Aruba Networks

Wireless technology is becoming increasingly integrated into the world's networks. Recent innovations, such as offloading processing to wireless local area network (WLAN) switches at the network's edge, have cleared the way for large-scale enterprise deployments. However, despite improved maintenance and administration tools, switched WLAN networks are vulnerable to issues arising from the heterogeneous network environment, especially the integration of services such as voice over IP (VoIP). An open-industry enterprise services and security test event held from March 21 to March 25, 2005 at the University of New Hampshire InterOperability Laboratory (UNH-IOL) provided a backdrop for testing these solutions.

May 13, 2005 White Papers
Testing Triple Play Services and Security in Enterprise Networks Wireless, Bridge Functions, and VoX Consortiums

Testing scenarios, caveats and issues encountered in testing converged or "triple play" (voice, video, data) services and security in converged enterprise-class deployment scenarios.

May 4, 2005 White Papers
Software Defined Radio (SDR) Based Implementation of IEEE 802.11 WLAN Basedband Protocols Shravan Surineni

The IEEE 802.11 family of wireless LAN protocols defines multiple physical layers implementations of which direct sequence spread spectrum (DSSS, 802.11b) and orthogonal frequency division multiplexing (OFDM, 802.11a/g) are currently the most popular. Market pressures are forcing the convergence of multiple wireless protocols into the same access device, and shortened product design cycles dictate rapid prototyping of new or enhanced protocols. The computationally intensive signal processing algorithms and high data rates associated with these protocols necessitate dedicated hardware implementation of some portions of the signal processing chain, yet allocating separate hardware resources for each of the standards would make the "universal access device" bulky and inefficient. Re-using the same software-reconfigurable hardware to handle different processing algorithms would enable an efficient, flexible alternative to current prototyping and implementation methods. In this thesis, the feasibility of using Software Defined Radio architectures as a prototyping tool for wireless LAN baseband signal processor implementations is explored. Signal processing architectures and algorithms for DSSS and OFDM protocols were developed in the Simulink and Matlab environments, and were then translated to VHDL hardware descriptions. A reference design for a OFDM transmitter was synthesized for implementation on a Xilinx Virtex II FPGA, and functional and timing simulations verified the design correctness.

December 1, 2004 Theses
US Frequency Allocation Chart US Dept. of Commerce

The United States Commerce Department's National Telecommunications and Information Administration (NTIA) spectrum chart, dated October 2003, depicts the radio frequency spectrum allocations to radio services operated within the United States.

October 1, 2003 External Links