Wi-Fi Update: WLANs For Next-Generation Application
[ Source: Wi-Fi Alliance ]
May 2008-
Wi-Fi Alliance notes that Wi-Fi Certified products bring interoperability and better user experience to WLAN technology; more than 4,300 products certified since March 2000. The Alliance provides this presentation to detail other benefits of Wi-Fi.
Optimal Superimposed Pilot Selection for OFDM Channel Estimation
[ Source: University of Melbourne ]
January 2008-
Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient modulation scheme for high-bit-rate wireless communication over multipath fading channels. It is expected that OFDM will play a major role in next generation (B3G and 4G) mobile wireless systems. This research paper from University of Melbourne presents an optimal strategy for utilizing superimposed pilots for OFDM channel estimation using Wiener filtering. An algorithm is formulated to determine the optimal rectangular set of time-frequency samples for channel ....
Cisco ITP MAP Gateway for Public WLAN SIM Authentication and Authorization
[ Source: Cisco ]
January 2008-
Global System for Mobile Communications (GSM) operators are recognizing the need for high-speed wireless data services. Cisco Systems has embarked on an effort to enable authentication of WLAN subscribers using the existing and well-proven GSM-based user authentication and existing GSM provisioning facilities. Cisco ITP MAP Gateway function enables existing GSM service providers to fully integrate 802.11 technology into their existing GSM network using subscriber-identity-mobile (SIM) cards. Cisco ITP MAP Gateway function enables a WLAN authentication ....
Traffic-Aware Channel Assignment in Wireless LANs
[ Source: University of Texas ]
January 2008-
This research paper discusses how campus and enterprise wireless networks are increasingly characterized by ubiquitous coverage and rising traffic demands. Efficiently assigning channels to Access Points (APs) in these networks can significantly affect the performance and capacity of the wireless LAN. Several research studies have tackled this issue. However, even the state-of-the-art approaches assign channels without considering prevailing traffic demands. The channel assignment problem has a parallel in the wire-line world, where recent work has ....
Troubleshooting WLAN Connectivity
[ Source: Hewlett-Packard ]
January 2008-
This paper from Hewlett-Packard provides information to help identify and troubleshoot common problems in a wireless LAN in which there is at least one Access Point (AP) connected to a wired LAN and one or more wireless stations. ProCurve wireless access points operate best when loaded with the most current version of software. Upgrade to the latest version of software early within the troubleshooting process.
The Power Line Transmission Characteristics for an OFDM Signal
[ Source: Massachusetts Institute of Technology ]
January 2008-
This research paper measures what influence the sinusoidal transmission characteristics of the electric power line with various forms gave to the transmission characteristic of OFDM (Orthogonal Frequency Division Multiplexing) signal through PLC (Power Line Communication system) modem. The electric power line transmission line with various forms in a real environment is classified into two basic elements, which are an outlet type branch and a switch type branch. Next, PHY rate (Physical rate) is measured for ....
Airport Wireless LAN: Technology Survey and Simulation Tool Development
[ Source: MITRE ]
January 2008-
The 5000-5250 megahertz (MHz) frequency band is allocated to the Aeronautical RadioNavigation Service (ARNS) on an international basis. The 5030-5091 MHz portion is in use for Microwave Landing System (MLS) applications. The aviation community is exploring other applications in the 5091-5150 MHz band, referred to as C-band in this report, to support aeronautical applications. This paper documents a preliminary investigation on the applicability of the Wireless Local Area Network (WLAN) and cellular network technologies, for ....
WEP Cloaking - Maximizing ROI From Legacy Wireless LAN
[ Source: AirDefense ]
January 2008-
Wired Equivalent Privacy (WEP) is the encryption protocol defined in the original IEEE 802.11 standard for Wireless Local Area Networks (WLANs). Several known vulnerabilities and attack tools have compromised WEP making it unsuitable for secure WLAN implementations, without additional layers of security. AirDefense’s patented WEP Cloaking solution is designed to make WEP virtually invulnerable to known attacks and tools, providing a robust layer of protection for legacy WLANs. The solution does not require any hardware ....
Spatial Multiplexing for Outdoor MIMO-OFDM Systems With Limited Feedback Constraint
[ Source: Uppsala University ]
January 2008-
Next generation mobile communication systems are expected to place stringent demands for high quality and high data rates over mobile radio channels. Recent studies on Multiple Input Multiple Output (MIMO) antenna systems with Orthogonal Frequency Division Multiplexing (OFDM) signaling have shown that spatial-frequency parallel processing at both transmitter and receiver, combined with fast adaptive transmission, is able to provide significant increases in spectral efficiency. This research paper from Uppsala University proposes a spatial multiplexing technique ....
Space-Time-Frequency Transmit Diversity in Broadband Wireless OFDM Systems
[ Source: DoCoMo Euro-Labs ]
January 2008-
This paper published by DoCoMo Euro-Labs considers space-time - frequency transmits diversity with orthogonal designs in a broadband OFDM system. On capacity considerations for Gaussian as well as real world signal constellations, it show that the concatenation of an outer error control code, a bit interleaver and orthogonal spatial transmit diversity provides an attractive MIMO scheme which is robust to channel imperfections such as spatial correlation. It proposes an application of orthogonal designs for space-time-frequency ....