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Hong S.G.,Hughes Network Systems LLC | Schulzrinne H.,Columbia University
IEEE Communications Magazine | Year: 2013

We propose a signaling architecture for network traffic authorization, called Permission-Based Sending (PBS), aiming to prevent DoS attacks and other forms of unauthorized traffic. Toward this goal, PBS takes a hybrid approach: a proactive approach of explicit permissions and a reactive approach of monitoring and countering attacks. PBS uses a concept similar to existing capability-based systems in the manner in which the sender should get authorization (permission) from a receiver for flows. However, PBS introduces new and practical approaches to overcome the deficiencies (the difficulty of obtaining permission and incompatibility with current network architecture) of those systems. On-path signaling enables easy installation and management of the permission state. Working on current network protocols supports compatibility and allows PBS to be deployed in existing networks. In addition, a monitoring mechanism provides a second line of defense against attacks. Our analysis and performance evaluation show that PBS is an effective and scalable solution to prevent several kinds of attacks, and improves the resilience of the system against network failure by using soft-state mechanisms. © 1979-2012 IEEE. Source


Gopal R.,Hughes Network Systems LLC | Cynamon C.,Space Systems Loral LLC
31st AIAA International Communications Satellite Systems Conference, ICSSC 2013 | Year: 2013

Today's satellite-based sensing can be transformed into a ubiquitous and cost effective capability with the use of a network-centric architecture. This architecture provides interoperability across multiple sensors, either LEO satellites or hosted payloads on LEO satellites, generic GEO communications satellites, multi-purpose gateways, cloud-based computing, and universal end-product dissemination. A key differentiator of this architectural approach is the use of the Ku-and Ka-band GEO communications satellite systems that can relay LEO-sensing data to the ground for processing and distribution. This architecture, with automated hand-offs across multiple GEO satellites, reduces data delivery latency and costs with the use of the existing GEO constellation and gateways worldwide. A local buffering mechanism on the LEO sensors preserve temporarily stored data (for future replay) during hand-offs or when there is no GEO satellite coverage. Our standards-based architecture comprising Ku/Ka-band LEO-GEO links strikes an effective balance among risk, functionality, and operational costs compared to the use of other (bandwidth constrained and expensive) RF bands and purpose built GEO relay satellites. Source


Gopal R.,Hughes Network Systems LLC
International Journal of Satellite Communications and Networking | Year: 2011

This paper introduces a net-centric architecture based on ETSI and TIA Regenerative Satellite Mesh-A (RSM-A) standard that uses satellites with on-board packet switching. An Internet Engineering Task Force (IETF) IP protocol family-based extension of RSM-A for enhanced user interoperability, combined with multiple spot beam satellite implementation facilitates higher capacity, easy deployment and full mesh terminal-to-terminal operation that is required for managing emergency situations. This Net-centric Satellite Mesh (NSM) architecture adequately addresses the current and evolving networking needs for emergency-management information systems that can generate high data rate and real-time multi-media traffic. The NSM architecture supports the evolving IETF Emergency Telecommunications Service standards with packet flow-level admission control for guaranteed packet quality-of-service needed by real-time unicast and multicast traffic over satellite networks. The multi-plane architectural discussion is supported with measurements of selected end-to-end application behavior that validate the technical capabilities of NSM by using a pioneering Ka band satellite system, based on RSM-A, which has recently been deployed in North America. © 2010 John Wiley & Sons, Ltd. Source


Briceno L.D.,Colorado State University | Siegel H.J.,Colorado State University | MacIejewski A.A.,Colorado State University | Oltikar M.,Colorado State University | And 6 more authors.
IEEE Transactions on Parallel and Distributed Systems | Year: 2011

This work considers the satellite data processing portion of a space-based weather monitoring system. It uses a heterogeneous distributed processing platform. There is uncertainty in the arrival time of new data sets to be processed, and resource allocation must be robust with respect to this uncertainty. The tasks to be executed by the platform are classified into two broad categories: high priority (e.g., telemetry, tracking, and control), and revenue generating (e.g., data processing and data research). In this environment, the resource allocation of the high-priority tasks must be done before the resource allocation of the revenue generating tasks. A two-part allocation scheme is presented in this research. The goal of first part is to find a resource allocation that minimizes makespan of the high-priority tasks. The robustness for the first part of the mapping is defined as the difference between this time and the expected arrival of the next data set. For the second part, the robustness of the mapping is the difference between the expected arrival time and the time at which the revenue earned is equal to the operating cost. Thus, the heuristics for the second part find a mapping that minimizes the time for the revenue (gained by completing revenue generating tasks) to be equal to the cost. Different resource allocation heuristics are designed and evaluated using simulations, and their performance is compared to a mathematical bound. © 2011 IEEE. Source


Gopal R.,Hughes Network Systems LLC | Ravishankar C.,Hughes Network Systems LLC
32nd AIAA International Communications Satellite Systems Conference, ICSSC 2014 | Year: 2014

Software Defined Satellite Network (SDSN), similar to SDN[1], decouplesdata plane functions from control planefunctions. SDSNbenefitsfrom logically centralized network state knowledgeand decision makingthatenablesoptimalresource allocationsfor dynamic packet processing and transmission.An SDSN networknodeusesforwarding tables configured bya centralized system controllerto governpacket routingwithembeddedLayer 2switchwithout requiringelaborate Layer 3 controlplanesoftwareimplementationin every satellite node.Besides upper layer packet queuing and switching, SDSNs also involveradiotransmission links and encompassassociated modulation, coding, and resource allocation functionswithdynamic control. SDSN architectural conceptscan be illustratedwith the SPACEWAYsystemwhichusesa GEOsatellitecomprisingKa band spotbeamsand a 10 Gbpspacket processingswitch. The onboard switching functionisorchestratedby a ground-based system controller, withcentralized support for addressing, routing, and packet flow management. The SDSN building blocksand performance objectives can be extended toaddress inter-satellitepacket routing usinga constellation of satellites with inter-satellite links and enhanced routingand resource managementfunctionat the controller. Besides GEO, LEO, and MEOsatellites the SDSN architecture andtechniques for addressing, routing, QoS, traffic engineering, and resource managementcan also be utilizedfor aerial and high altitude networking platforms. Source

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