National Institute of Standards and Technology

Latest Content From National Institute of Standards and Technology

Whitepaper: Link Assessment in an Indoor 802.11 Network

by National Institute of Standards and TechnologyJan 01, 2008

This paper presents the pragmatic results and analysis of a link variability study for an indoor, stationary 802.11 network subject to external interference. The objective is to portray the relationships between the packet loss rate on a link and the transmitter-receiver distance, the SNR as reported by the 802.11 cards, and time. New results confirm that distance is not predictive of link reliability. Furthermore, attempting to estimate the packet loss rate by counting missing packets can lead to large estimation errors and latency for estimation parameters of practical interest.

Whitepaper: Cross-Layer Feedback Control for Video Communications Via Mobile Ad-Hoc Networks

by National Institute of Standards and TechnologyJan 01, 2008

For many tactical operations, communication between mobile nodes (such as robotic vehicles) requires high performance sensing channels capable of transmitting high quality video signals over unstructured mobile networks. This necessitates a peer-to-peer network assembly of wireless multihop ad-hoc routing. In addition, recent advances in Wireless LAN (WLAN) technologies such as the IEEE 802.11 standard, have provided new opportunities to develop an experimental platform to design and assess ad-hoc networks for transmission of multimedia information in realistic environments. The IEEE 802.11 standard defines the Carrier Sense Multiple Access protocol combined with Collision Avoidance (CSMA/CA).

Whitepaper: Studies of One-to-One Fingerprint Matching With Vendor SDK Matchers

by National Institute of Standards and TechnologyJan 01, 2008

NIST has conducted testing of one-to-one SDK (Software Development Kit) based COTS (Commercial Off-The-Shelf) fingerprint matching systems to evaluate the accuracy of one-to-one matching used in the US-VISIT program. Fingerprint matching systems from eight vendors not used in US-VISIT were also evaluated to insure that the accuracy of the matcher tested was comparable to the most accurate available COTS products. The SDK based matching application was tested on 12 different single finger data sets of varying difficulty. The data sets used and the ranking of the systems are discussed in detail in the paper from National Institute of Standards and Technology.

Whitepaper: NIST Net - A Linux-Based Network Emulation Tool

by National Institute of Standards and TechnologyJan 01, 2008

Testing of network protocols and distributed applications has become increasingly complex, as the diversity of networks and underlying technologies increase, and the adaptive behavior of applications becomes more sophisticated. This paper presents NIST Net, a tool to facilitate testing and experimentation with network code through emulation. NIST Net enables experimenters to model and effect arbitrary performance dynamics (packet delay, jitter, bandwidth limitations, congestion, packet loss and duplication) on live IP packets passing through a commodity Linux-based PC router. This paper describes the emulation capabilities of NIST Net; examine its architecture; and discuss some of the implementation challenges.