Knowledge Base

used at UNH-IOL for training and discussion

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.

Interworking issues continue to be an obstacle to achieving scale on SIP Trunk deployments. Due to variances in the SIP profiles supported by different SIP Trunk products, Service Providers and vendors are forced to spend significant time and people resources to identify and resolve interworking issues for each new SIP-PBX/SSP-network combination. The SIP Forum has been actively working on multiple fronts to resolve this interworking roadblock, and to move the rollout of SIP Trunking service toward more of a plug-and-play deployment model.

This session provides a status update on two important SIP Forum initiatives in this area:

1. The SIPconnect 1.1 Recommendation: This recommendation defines a SIP profile for the SIP Trunk interface between a SIP-PBX and Service Provider network. It defines procedures to resolve common interworking issues at the SIP Trunk interface for capabilities such as security, PBX registration, and call features.

2. The SIPconnect 1.1 Interop and Compliance Program: The focus of this program is to encourage the adoption of SIPconnect 1.1 through a series on interop events, and ultimately to develop a rigorous test-platform-based compliance program that will enable vendors to indicate product compliance with SIPconnect 1.1.

The presence of crosstalk is a major detriment to the performance of Digital Subscriber Line (DSL) transceivers. It is therefore important to test performance under a wide variety of crosstalk scenarios. This thesis presents the development of a crosstalk noise generation system as a tool for DSL performance testing. Where many commercially available solutions are limited to specific testing needs, the system presented here is universal and can simulate virtually any noise scenario conceivable for DSL deployment.
Several requirements for the accurate frequency domain modeling of DSL crosstalk are presented. The time domain properties of crosstalk were also studied with particular attention paid to the amplitude distribution. The importance of a Gaussian amplitude distribution and the limiting effect of a finite-length pseudo-random crosstalk sequence on the "tail" of the Gaussian distribution were investigated. A method of forcing finite-length crosstalk sequences to have a "near-Gaussian" amplitude distribution is proposed.

A spreadsheet to help one develop a sense of time scales

Overview of the basic SCSI information needed to identify each command.

SATA uses in the enterprise
SATA uses in personal computing
Device form factors
ODDD, HDD and SSD Devices
Port Multipliers.

SATA uses in the enterprise
SATA uses in personal computing
Device form factors
ODDD, HDD and SSD Devices
Port Multipliers.

SATA uses in the enterprise
SATA uses in personal computing
Device form factors
ODDD, HDD and SSD Devices
Port Multipliers.

Presenting the topics: 8b10b Encoding, SATA Primitive, ALIGN use in SATA, Hold use, & Cont use.

Overview of the Chapter 8 OOB and Phy Power States.

Overview on the device command Layer Protocols.

Transport layer overview.

Overview of the SATA PHY Layer.

Overview on the application layer.

Overview of the types of SAS Devices, SAS/SATA Interop, and cables and Connector Types.

Overview of the physical Layer Test Suites and Equipment, Protocol test suites and equipment and Interop testing.

Presenting the topics of Transport Layer Protocols: SSP, SMP and STP.

Presenting Clause 7 with a primitive Overview, Primitive Types and definitions, and open Connection Handshake.

Discussing OOB State Machine, speed negotiation, 8b10B Encoding and Synchronization State Machine.

Topics of transmission Speeds and Unit Intervals, OOB Construction, and Differential Signaling.

The UNH-IOL is an approved RVU Alliance Independent Certification Vendor (ICV). With a UNH-IOL Home Networking (HNC) membership companies are able to certify an unlimited amount of devices in a year. For companies looking to obtain RVU Alliance certification for only a few devices a year, the HNC offers pay-as-you-go RVU test services. Please note, these test services are available to RVU Alliance™ members only.

In the growing world of ubiquitous networking, people often take for granted that interoperability exists between their network devices and the networks they are connecting to. Consortium vendors and international standards bodies are formed to establish standards on how devices should behave if they wish to communicate with each other. However, verifying conformance to these standards is no trivial task. The RSP was developed to add to the Wireless LAN Consortium's testing capabilities. The RSP has the capability of reacting to wireless traffic in a manner that tests a device's handling of uncommon, but very important conditions. The RSP Consists of an 802.11 MAC'less card from Intersil, interfaced to an Altera programmable logic device, which in turn communicates with a PC through a USB microcontroller.

This document describes the OSPF Protocol.

The issue of radio frequency interference in Digital Subscriber Line (DSL) networks is of particular concern in urban areas with many strong radio sources nearby. Prior work by Harris et al showed drastic decreases in DSL link capacity with a narrowband AM interferer. The purpose of this thesis was to investigate in more detail the mechanisms underlying the capacity reduction observed by Harris. In this thesis, an ADSL system, channel, and radio frequency interference noise were simulated in MATLAB. The capacity reduction due to different RF ingress conditions was studied. It was found that a narrowband interferer does not cause a drastic decrease in capacity if time and frequency domain equalizers are employed in the receiver. Contrary to Harris?s suggestions that spectral spreading of the interferer is the primary cause of capacity reduction, it is shown in this thesis that such spreading is a secondary effect and that the unequalized channel is the predominant source of capacity reduction.