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At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

A TDMA Broadcast Satellite/Ground Architecture for the Aeronautical Telecommunications Network

An initial evaluation of a TDMA satellite broadcast architecture with an integrated ground network is proposed in this study as one option for the Aeronautical Telecommunications Network (ATN). The architecture proposed consists of a ground based network that is dedicated to the reception and transmissions of Automatic Dependent Surveillance Broadcast (ADS-B) messages from Mode-S or UAT type systems, along with tracks from primary and secondary surveillance radars. Additionally, the ground network could contain VHF Digital Link Mode 2, 3 or 4 transceivers for the reception and transmissions of Controller-Pilot Data Link Communications (CPDLC) messages and for voice. The second part of the ATN network consists of a broadcast satellite based system that is mainly dedicated for the transmission of surveillance data as well as En-route Flight Information Service Broadcast (FIS-B) to all aircraft. The system proposed integrates those two network to provide a nation wide comprehensive service utilizing near term or existing technologies and hence keeping the economic factor in prospective. The next few sections include a background introduction, the ground subnetwork, the satellite subnetwork, modeling and simulations, and conclusion and recommendations.

Shamma, Mohammed A.↗
NASA NTRS2001

Medicine in long duration space exploration: the role of virtual reality and broad bandwidth telecommunications networks

Safety of astronauts during long-term space exploration is a priority for NASA. This paper describes efforts to produce Earth-based models for providing expert medical advice when unforeseen medical emergencies occur on spacecraft. These models are Virtual Collaborative Clinics that reach into remote sites using telecommunications and emerging stereo-imaging and sensor technologies. c 2001. Elsevier Science Ltd. All rights reserved.

Non-NASA Center↗
NASA NTRS2001

Achieving QoS for Aeronautical Telecommunication Networks over Differentiated Services

Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications. ATN has therefore, been designed as a standalone network which implies building an expensive separate network for ATN. However, the cost of operating ATN can be reduced if it can be run over a public network such as the Internet. Although the current Internet does not provide QoS, the next generation Internet is expected to provide QoS to applications. The objective of this paper is to investigate the possibility of providing QoS to ATN applications when it is run over the next generation Internet. Differentiated Services (DiffServ), one of the protocols proposed for the next generation Internet, will allow network service providers to offer different QoS to customers. Our results show that it is possible to provide QoS to ATN applications when they run over a DiffServ backbone.

Bai, Haowei↗
NASA NTRS2001

Sub-microradian pointing for deep space optical telecommunications network

This presentation will cover innovative hardware, algorithms, architectures, techniques and recent laboratory results that are applicable to all deep space optical communication links, such as the Mars Telecommunication Network to future interstellar missions.

deep-space optical communication tracking pointing↗
NASA NTRS1995

Lunar Telecommunications

This paper reviews the telecommunications needs of future lunar orbiters and rovers and considers ways in which these needs can be met with ground-based tracking resources.

Lunar Prospector↗
NASA NTRS1994

Automated Consultation for the Diagnosis for Interplanetary Telecommunications

SHARP (Spacecraft Health Automated Reasoning Program) is a knowledge-based consultant for diagnosing problems in NASA'a Deep Space Network (DSN) telecommunications link in near real-time...This paper describes the most recent version, which is an operational system used by spacecraft mission contollers; previous versions are described elsewhere...

DSN deep space network↗
NASA NTRS1994

Microtechnology in Telecommunications for Spacecraft Cost and Mass Reduction

This paper examines the incorporation of both microelectronics and micromachining (termed microtechnologies) as applied to deep space telecommunication subsystems. Using the Pluto Fast Flyby Pre-Project as a main case study we have reduced the subsystem mass by 50%.

MCM amplifiers filters switches Goldstone Deep Spa↗
NASA NTRS1993

Ground Antennas in NASA's Deep Space Telecommunications

Ground antennas are the major visible components of NASA's Deep Space Network (DSN). The role, key characteristics, and performance of these antennas in deep space telecommunications are described.

ground antenna antenna deep space network DSN tele↗
NASA NTRS2006

End-to-end information system concept for the Mars Telecommunications Orbiter

The Mars Telecommunications Orbiter (MTO) was intended to provide high-performance deep space relay links to landers, orbiters, sample-return, missions, and approaching spacecraft in the vicinity of Mars, to demonstrate interplanetary laser communications, to demonstrate autonomous navigation, and to carry out is own science investigations.

EEIS↗
NASA NTRS2006

Telecommunications IT and navigation for future Mars exploration missions 2006 IEEE Aerospace Conference

There are three primary drivers behind current investments in telecommunications information technology and navigation. One is finding ways to maximize the volume of science data returned from missions since i nstrument data generation often exceeds communication bandwidth. Another is to provide the necessary technology to enable networked spacecraft around Mars. The third driver is to enable more precise landing so in-situ vehicles can be placed in the more scientifically interesting regions. This paper describes the current NASA investments in these areas funded through the NASA Mars Technology Base Program NRA.

data compression↗
NASA NTRS2002

Comparison of VDL Modes in the Aeronautical Telecommunications Network

VHF Digital Link (VDL) has been identified as a method of communication between aircraft and ground stations in the Aeronautical Telecommunications Network (ATN). Three different modes of VDL have been suggested for implementation. Simulations were conducted to compare the data transfer capabilities of VDL Modes 2, 3, and 4. These simulations focus on up to 50 aircraft communicating with a single VDL ground station. The data traffic is generated by the standard File Transfer Protocol (FTP) and Hyper Text Transfer Protocol (HTTP) applications in the aircraft. Comparisons of the modes are based on the number of files and pages transferred and the response time.

Bretmersky, Steven↗
NASA NTRS2001

Performance of a Regional Aeronautical Telecommunications Network

This paper reports the findings of the simulation of the ATN (Aeronautical Telecommunications Network) for three typical average-sized U.S. airports and their associated air traffic patterns. The models of the protocols were designed to achieve the same functionality and meet the ATN specifications. The focus of this project is on the subnetwork and routing aspects of the simulation. To maintain continuous communication between the aircrafts and the ground facilities, a model based on mobile IP is used. The results indicate that continuous communication is indeed possible. The network can support two applications of significance in the immediate future FTP and HTTP traffic. Results from this simulation prove the feasibility of development of the ATN concept for AC/ATM (Advanced Communications for Air Traffic Management).

Bretmersky, Steven C.↗
NASA NTRS2006

Mars Science and Telecommunications Orbiter: Report of the Science Analysis Group, March 2006

This document reports the findings of the Mars Science and Telecommunications Orbiter (MSTO) Science Advocacy Group (SAG), which was convened by the Mars Exploration Program Analysis Group (MEPAG) and the Mars Exploration Office at JPL to identify and prioritize areas of Mars atmospheric and surface science objectives for Mars that can be accomplished from orbit on a MSTO like mission.

orbiter↗
NASA NTRS2007

Space Telecommunications Radio System (STRS) Architecture Goals/Objectives and Level 1 Requirements

The Space Telecommunications Radio System (STRS) Architecture Requirements Document provides the basis for the development of an open architecture for NASA Software Defined Radios (SDRs) for space use. The main objective of this document is to evaluate the goals and objectives and high level (Level 1) requirements that have bearing on the design of the architecture. The goals and objectives will provide broad, fundamental direction and purpose. The high level requirements (Level 1) intend to guide the broader and longer term aspects aspects of the SDR Architecture and provide guidance for the development of level 2 requirements.

Briones, Janette C.↗