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Flow-aware
Networking – Solving the Quality of Service (QoS) Challenge for IP Coverged
Networks Mike Raymond Caspian Abstract:
Practical Use of the Internet
Protocol to Command Satellites and Payloads Lloyd Wood Cisco Systems Work with CLEO, the Cisco router in Low Earth Orbit, and with the Disaster Monitoring Constellation built by Surrey Satellite Technology Ltd, has shown how the Internet Protocol can be successfully used for satellite platforms and for payload communications. This work validates and builds on Keith Hogie et al's earlier demonstration work on SSTL's UoSAT-12, using the simple architectural approach outlined in [1]. Reasons why this architectural approach is compelling and useful are discussed. [1] K. Hogie, E. Criscuolo and R. Parise, Using standard Internet Protocols and applications in space, Computer Networks, special issue on Interplanetary Internet, vol. 47 no. 5, pp. 603-650, April 2005.
A Systemic View to the Nature of Mobility
and Connectivity in Space and Implications on
the Design of Space Network Protocol
Suits Prepared As a part of NASA Faculty Fellowship Program August 2005 by: By NASA Fellow Dr. Javed I. Khan Media Communications and Networking Research Lab Department of Computer Science along with NASA Colleagues Brenda L. Ellis, Larry McFarland, and Chuck Putt Office of the CIO Computational Environments Branch Phone: (216) 433-5214 What if the righteous place to implement
“hop-and-forward” mechanism is in the network layer but not at application or
transport layer? Is it possible
that congestion is an earthly phenomena- byproduct of human freewill and hardly
be an issue in cold lifeless space until it is deeply colonized? Can one
conceive a space routing protocol which will require zero inter-router
communication and still route packets with absolute precision? In this report we
examine the technical nature of the notion of ‘mobility’ and ‘connectivity’ in
the context of space networking and seek answers to the questions like
above.
Support for
the Internet Paradigm in the Transformational Satellite Communications System
(TSAT) Carl Sunshine The Aerospace Corporation 310-336-6991 TSAT is being designed to provide a combination of circuit and packet communications services for mobile and deployed military users in the next decade. TSAT will extend Internet technology into space, with attention to the extra security, endurance, and priority requirements necessary in a military environment. The briefing will summarize the baseline Government Reference Architecture for the system, with emphasis on meeting the challenges of extending the Internet architecture into a military space environment.
Getting to Lunar Sorties: The Need
for IP Protocols and Industrial-Strength Solutions for Near-Term Lunar Human
Stephen Braham,
warp@polyfab.sfu.ca Abstract:
Internetworking Over SpaceWire:
Design of a Non-Broadcast Address Resolution Protocol and Encapsulation Service
Sandra G. Dykes, Robert Klar, Allison Roberts, Buddy Walls, Mark A. Johnson, Kristian Persson {sandra.dykes, robert.klar, allison.roberts, buddy.walls, mark.johnson, kristian.persson}@swri.org Southwest Research Institute Standard communication protocols and existing OS network stacks can reduce software development time, cost, and errors. For this reason, spacecraft onboard communication systems are gradually moving from shared bus architectures to switched networks and standard protocols. Ethernet is the dominant switched network technology on Earth, and is one contender for the space environments. In Ethernet, the switches are responsible for link-layer broadcasts. To avoid forwarding loops, the switches must continuously learn network topology and build a minimum spanning tree for message delivery. However, these algorithms add complexity and circuitry which increases mass and power requirements. SpaceWire, a recent ESA standard, is gaining popularity because of its simple circuitry, low power consumption, and high-link speed. Although SpaceWire has many advantages, it lacks a link-layer broadcast mechanism. Broadcasts are necessary to support automatic network configuration and discovery software such as the Address Resolution Protocol (ARP) and Dynamic Host Configuration Protocol (DHCP). Address resolution tables and host IP addresses are manually configured on SpaceWire networks. Moreover, the SpaceWire standard does not yet specify a method for supporting multiple upper layer protocols such as IP and CCSDS. This presentation will describe the design of a link-layer broadcast service and an encapsulation service for SpaceWire. The encapsulation service provides a message multiplexing / demultiplexing functionality that enables multiple higher-layer protocols to operate over the same physical link. Implementing this service in the host driver software enables SpaceWire to automatically and simultaneously support IPv4, IPv6 and CCSDS SCPS-NP protocol stacks, as well as high-performance custom applications that interface directly to the driver. Our link-layer broadcast mechanism is implemented at the hosts rather than at the SpaceWire routers. The design is compliant with the SpaceWire specification and can be implemented solely within the driver software. No changes are required to the SpaceWire specification, routers, or host interface hardware. The algorithm introduces the concept of a SpaceWire subnet, which consists of a router and its directly connected hosts. The advantage of this approach is that it avoids configuration by using either SpaceWire port addressing or its packet distribution mechanism. We believe the ability of our protocols to simplify network management and to support IP and other higher-layer protocols is an important step forward and will lead to more rapid adoption of SpaceWire for future missions.
Space OSPF - Shortest Delay Intermittent Pathway Routing With Mobile Routers
Nouman Bantan & Javed I. Khan Internetworking and Media Communications Research Laboratories Department of Computer Science, Kent State University 233 MSB, Kent, OH 44242 USA nbantan@cs.kent.edu & javed@kent.edu OSPF routing protocol has powerful scalability and stability features because of its ability to divide routing domain into areas and messages into short on-demand link state messages. Recently, we have proposed a space version of OSPF routing called Space OSPF. This protocol is capable of handling intermittent paths and model-based router mobility in addition to its powerful scalability features. It can compute shortest delay paths over conventional concurrent link based pathways as well as on intermittent non-concurrent link based pathways for store-and-forward communication. In this paper we will present the performance of this new protocol in real space scenarios. It dramatically improves on several other routing algorithms proposed for space with near optimum routing performance.
Lessons
learned using Flight IP on moderate fidelity testbed with Radhard Cisco
router By Greg Menke Hugh Arif Global Defense, Space and Security Group Cisco Systems, Inc. This paper contains the benchmark and testing results of a flight-qualified, rad-hard Cisco router acting as the primary communications interface of a simulated spacecraft with IP as the end-to-end communications protocol. CPU and memory utilization figures are given for clear text and encrypted space-link communications. Operational configuration scenarios are discussed and conclusions are reached about the unique requirements COTS IP routers must work under when integrated into spacecraft.
IP For Responsive Microsats – A
Practical Approach Assi Friedman,
Jeffrey Janicik, jjanicik@innoflight.com Innoflight Inc. Phone: (858) 638-1580 Fax: (858) 638-1581 www.innoflight.com Using Internet Protocols on smallsats started as a grass
roots effort to take advantage of commercial hardware and software and save
development time, money, and reduce risk.
These premises are still exist today within the community. In addition, even though the
primary users of microsats nowadays are government customers (in the
There are many
spacecraft tracking stations available for government and commercial
networks in the Innoflight has been working on a number of microsat IP technology solutions that will enable spacecraft builders to purchase COTS IP enabled hardware and software package for both the ground and flight segments. This presentation will describe how Innoflight integrated traditional IP/HDLC with CCSDS standards, and Type-1 encryption to provide users with secure, high performance IP link between the spacecraft LAN and the ground segment. C. Okino, W. Kwong, J. Pang, J. Gao, and L. Clare
Jet Propulsion Laboratory In this work, we examine the use
of off-the-shelf Voice-over-IP (VOIP) for the space environment. Our initial
focus is on VOIP based on open source implementations of the Session Initiation
Protocol SIP (RFC 3261) and the Real Time Protocol RTP (RFC 3550). We also
investigate SIP extensions to enable voice operations in situations where
potentially there is only a simplex link or one direction of the duplex path
suffers a substantial outage during a connection. We examine the use of VOIP
applications for lunar space scenarios. Results are derived using our space
communications testbed, which incorporates underlying space network protocols
and captures channel error and propagation delay effects. We address the impacts
of the unique characteristics and needs of the space environment in the
performance measurements for voice. Clayton Okino
Jet Propulsion Laboratory
Pasadena, CA 91109
(818) 393-6668
Clayton.M.Okino@jpl.nasa.gov
Winston Kwong
Jet Propulsion Laboratory
Pasadena, CA 91109
(818) 354-5953
Winston.Kwong@jpl.nasa.gov Jackson Pang
Jet Propulsion Laboratory
Pasadena, CA 91109
(818) 393-0466
Jackson.Pang@jpl.nasa.gov Jay Gao Jet Propulsion Laboratory
Pasadena, CA 91109
(818) 354-9528
Jay.L.Gao@jpl.nasa.gov Loren Clare Jet Propulsion Laboratory
(818) 354-1650
Loren.P.Clare@jpl.nasa.gov
A Security Model for Space Based
Communications
As space missions become more complex and interactive the need for a comprehensive and rigorous security infrastructure becomes obvious. This framework should include all elements including space assets, ground systems, and distribution of data products. Although a myriad of security products and solutions have been developed recently, a comprehensive, directed methodology for implementing the correct technologies for space missions has not been developed. Based on our experience with securing NASA’s supercomputer assets and a high-speed wide area network we will present the requirements for space mission security. This will include an overview of current Internet-based security technologies and how they were assessed for inclusion in the NASA Research and Engineering Network (NREN) security plan and later implemented. Further discussion will include strategies for developing a viable security framework, security for onboard payload, operations in a secure environment and securing data products distributed to a wide array of off-site and out of agency principal investigators.
A Preferred Service Architecture for Payload Data
Flows Ray Gilstrap Ken Freeman Thom Stone Abstract:
Simulation of Delay-Tolerant Network Protocols in Space
Networks John Segui and Esther Jennings Jet Propulsion Laboratory John.Segui@jpl.nasa.gov, Esther.Jennings@jpl.nasa.gov (818) 354 9191, (818) 354 1390 In space exploration missions, the coordinated use of spacecraft as communication relays increases the efficiency of the endeavors. To conduct trade-off studies of the performance and resource usage of different communication protocols and network designs, JPL designed a comprehensive extendable tool, the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE). The design and development of MACHETE began in 2000 and is constantly evolving. Currently, MACHETE contains Consultative Committee for Space Data Systems (CCSDS) protocol standards such as Proximity-1, Advanced Orbiting Systems (AOS), Packet Telemetry/Telecommand, Space Communications Protocol Specification (SCPS), and the CCSDS File Delivery Protocol (CFDP). MACHETE uses the Aerospace Corporation’s Satellite Orbital Analysis Program (SOAP) to generate the orbital geometry information and contact opportunities. Matlab scripts provide the link characteristics. At the core of MACHETE is a discrete event simulator, QualNet. Delay Tolerant Networking (DTN) is an end-to-end architecture providing communication in and/or through highly stressed networking environments. Stressed networking environments include those with intermittent connectivity, large and/or variable delays, and high bit error rates. To provide its services, the DTN protocols reside at the application layer of the constituent internets, forming a store-and-forward overlay network. The key capabilities of the bundling protocols include custody-based reliability, ability to cope with intermittent connectivity, ability to take advantage of scheduled and opportunistic connectivity, and late binding of names to addresses. In this presentation, we report on the addition of MACHETE models needed to support DTN, namely: the Bundle Protocol (BP) model. To illustrate the use of MACHETE with the additional DTN model, we provide an example simulation to benchmark its performance. We demonstrate the use of the DTN protocol and discuss statistics gathered concerning the total time needed to simulate numerous bundle transmissions.
Modeling
Sparse, Mobile Ad hoc Networks with Strong Physical Layer
Interactions David
Finkleman Anlaytical
Graphics, Inc. Abstract:
Dynamic
Bandwidth Allocation for a Space-to-ground
Relay Network Hui Zeng*, Michael Hadjitheodosiou &
John S. Baras HyNet, Institute for Systems Research MD 20742 E-mail:
{zengh, michalis, baras}@umd.edu
We focus on the allocation of bandwidth in a space relay network that supports several scientific spacecraft with a number of different streams on-board sharing a broadband satellite channel to send traffic to the ground. Our system model includes a number of mobile spacecraft (MS) in Lower Earth Orbit (LEO), a Geo-synchronous (GEO) relay satellite, and the ground network consisting of several ground stations (GS). The downlink channel of the relay satellite is shared by these spacecraft, which we model as streams with different priority levels going through a common queue and a router. The data will be delivered to the ground station through this relay. It is shown that a carefully designed time-varying bandwidth allocation based on the instant or statistical traffic from all users/flows performs better in terms of throughput and end-to-end delay. However, only short-term (time varying) bandwidth allocation may cause instability and will have difficulties in providing QoS guarantees and managing the long-term (average) behavior of all the users/flows. Hence, we propose a two-level bandwidth allocation in our implemented TDMA scheme. For a well-coupled framework with per user/flow average bandwidth management, we derive our long-term bandwidth allocation problem from the model discussed by Kelly, and draw some ideas from some other work. In addition, for instantaneous bandwidth management, we incorporate ideas from some recent work to formulate the short-term timeslot assignment problem and find the solution for optimal timeslot scheduling. By using simulation, the performance of a suitable MAC protocol with two-level bandwidth allocation is analyzed and compared with that of the existing static fixed-assignment scheme in terms of ETE delay and successful throughput. We also study the fairness among all the users under a special scenario and find that the pseudo-proportional fairness is achieved for our hybrid protocol. *Corresponding Author: Hui Zeng HyNet, Institute for System Research, Tel:
+301-405-7904
Fax:+301-314-8586 E-mail:
michalis@isr.umd.edu
Utilization
of Commercial Wireless Networking Technology in Simulated Martian
Environments Authors: Phillip DeLeon, Stephen Horan, Deva Borah, et al. Affiliation:
Corresponding Author: Stephen Horan (505-646-3117; shoran@nmsu.edu) This paper describes a three-part investigation into using commercial wireless technology to estimate the performance of 802.11-type networks in an outdoor planetary environment. The specific environment chosen for the studies is the landing environment of the Mars rovers. The general technique that has been developed can be applied to any location where suitably-detailed terrain information is available. The first phase of the project concerned acquiring high-resolution terrain data for the candidate landing sites and then making that data accessible for importation into commercial link planning software. The link planning software chosen was that used for planning cellular telephone links. This software uses ray-tracing techniques for radio propagation from a source to destination and not statistical estimation techniques. The second phase of the project is to use the terrain data and the link planning software to obtain RF coverage estimates and power delay profiles. These estimates are gotten at a number of locations within the predicted MER landing ellipses to see what variations can be found. The simulation estimates are validated against measurements made with local terrain features. The third phase of the project is to use the link predictions to estimate the effective performance of 802.11 wireless links in the outdoor environment. From the terrain data, we obtain estimates of the percent coverage, expected throughput of 802.11a and 802.11b links, and expected throughput based on modulation types (PSK-based or OFDM). This technique can be applied to other terrain environments, e.g. the lunar environment, if sufficient imaging and terrain composition details are known to generate the coverage models.
Low Cost Communication for Pico-Satellites – Experience
from the CubeSat UWE-I Mission Marco Schmidt, Florian
Zeiger, Michael Menth, and Klaus Schilling January 24, 2005 The pico-satellite UWE-1
( nched in the context of
the ESA SSETI-Initiative from the Russian launch site Plesetsk on October 27th,
2005. UWE-1 was built in the scope of the international Cubesat program
initiated by The mission objectives of the UWE-1 project comprise the test of new solar cells in space environment as well as the adaptation and optimization of existing communication technology and Internet protocols for pico-satellites. We used a modification of the 6pack protocol for the control of the Terminal Node Controller (TNC) and tuned the parameters of the AX.25 link layer protocol to maximize the data throughput. We compared the efficiency of the communication link on earth and in orbit under different weather conditions and distance. Thus, we have demonstrated with UWE-1 a proof of concept for a low-cost, flexible orbital test platform consisting of COTS components which uses communication protocols conform to Internet standards. The work explains the engineering constraints of our low-cost pico-satellite in particular regarding the communication part. It shows the adaptation and optimization of the proto- col layers and a practical assessment of the quality of the communication channel that we performed after UWE-1 was launched.
Design of a Fault-Tolerant Satellite
Cluster Link Establishment Protocol Authors: Stephen Horan and Praveen G.
Thonour Affiliation: Corresponding Author: Stephen Horan (505-646-3117;
shoran@nmsu.edu) In our previous presentations,
we gave the basic design for a link establishment protocol designed for a
satellite cluster environment. This basic design was for a single cluster of
satellites where channel errors are expected to occur and so the design would
need to allow the cluster to be automatically established even in this error
environment. This basic method was built around a UDP-based protocol developed
at NMSU and programmed in LabVIEW for development and ANSI C for use in the
NASA/GSFC software radio laboratory. In this paper, we will describe
improvements made over the past year to the initial algorithm. Enhancements made
to this algorithm include • Utilize multicast messaging to improve channel use
efficiency, • Permitting cluster members to enter and leave the
cluster, • Provide a method to allow new members to join the
cluster, • Provide a method to partition the cluster into
smaller partitions of single-hop neighbors, and • Provide a means for gateways between partitions.
These algorithm enhancements
were made in the same mode as the initial algorithm development: UDP-based
communications protocol, a LabVIEW development environment, and translation to C
for incorporation in the GSFC laboratory.
Using Networking Protocols in the
Design of a Nanosatellite Authors: Stephen Horan and George
Kuchera Affiliation: Corresponding Author: Stephen Horan (505-646-3117;
shoran@nmsu.edu) One of the goals of the
University Nanosatellite program is to have rapid design and integration of the
spacecraft components. A suite of networking protocols has been chosen for the
design of the NMSUSat as part of this program to allow the design to rapidly
progress from concept to working prototype. In particular, the design is
explicitly using standard protocols that are available to run on the flight
computer and the university’s ground station. The satellite flight computer is
based on a commercial PC-104 computer running Linux. The ground station uses a
PC running WindowsXP and tied to the campus network backbone. Typical
applications for the satellite design include: • NTP for synchronizing the satellite CPU clock to the
NMSU campus time server • MDP for file transfer applications
• Secure Shell for login The goal is to enable the
student designers to rapidly configure and operate the satellite with minimal
coding. The NMSUSat is currently in the prototype construction phase with the
final satellite build required to be done in spring 2007. Because of the
constraints of the Nanosat design environment, the design of the communications
is especially constrained. In this presentation, we will show the design
configuration and the results obtained to date with the prototype hardware and
software.
On NASA Earth Sciences Representative Instrument and
Sensor Web Framework1,2 Semion Kizhner, Wesley Powell and Umesh Patel National Aeronautics and Space Administration 301-286-1294 Semion.Kizhner-1@nasa.gov Meg Vootukuru Syneren Technologies Abstract—Transparent network-based adaptation and sharing of
space flight mission resources, including those of the
Space-Ground/Control-User-Communications segments, could greatly benefit from
utilization of Internet devices and protocols applied for Space or SpaceIP. This
had been demonstrated, in principle, by a few recent spaceflight experiments.
However, while the terrestrial part of the SpaceIP is well developed and
understood, the flight segment of SpaceIP is still in its infancy. Progress in
the developments of Space Segment enabled SpaceIP components will largely
determine the SpaceIP progress and acceptance in years to come. In this paper we
present an approach in developing related and enabling instrument-level
technologies based on the concept of Instrument Sensor Web. This paper presents
a two-fold approach, first in developing the theoretical framework for
instrument sensor webs and secondly - in developing an instrument electronics
component aspect of instrument sensor web which, in turn, will enable the
internetworking for space flight missions. The present view of a sensor web is
as of a distributed instrument comprised of many sensors and interconnected by a
heterogeneous communications system. We propose a different view of an
instrument as a sensor web, called Instrument Sensor Web. This concept is new
and different from the heritage concept of sensor web and it is a view from the
engineering perspective. This new view of an instrument as a sensor web is
amendable to earth science spaceflight missions (especially the missions
presently in proposal phase), such as Ocean Carbon, Ecosystem and Near Shore
mission. The sensor signal processing electronics building blocks for this
representative mission can be viewed as a sensor web with heterogeneous sensors
and heterogeneous interfaces, and with a combination of heritage electrical and
wireless interfaces. The topologies for these electronics building blocks can be
developed into enabling SpaceIP architectures, which will result in low cost,
redundant and intelligent on-board data pre-processing, solid state recorder
multi-function data housing, data compression, and data downlink protocols based
on SpaceIP. In this paper we present the outline of the theoretical framework
for an instrument sensor web and the signal and information processing elements’
system architectures required in smart sensor readout and information processing
integrated electronics circuits for the earth science class of spaceflight
missions. 1 U.S. Government work not protected by 2 Space Internetworking Workshop-2006 May 2-4, 2006
SIGMA: An
End-to-End Mobility Management Scheme for
Space Networks[1]
Abstract National Aeronautical and Space Administration (NASA) has been experimenting with Mobile IP to manage handovers of spacecrafts between ground stations. Mobile IP is an industry-standard that has been developed to handle mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as requirement of infrastructure change, high handover latency, high packet loss rate, and conflict with network security solutions. Researchers at The centralized DNS-based location management scheme of SIGMA provides for high survivability. The paper will compare the survivability of SIGMA with that of Mobile IP. SIGMA can interoperate with existing network security infrastructures such as Ingress filtering and IPSec fairly easily. The paper also describes the application of SIGMA to manage satellite handovers in space networks.
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