11,633 research outputs found
A Lightweight and Attack Resistant Authenticated Routing Protocol for Mobile Adhoc Networks
In mobile ad hoc networks, by attacking the corresponding routing protocol,
an attacker can easily disturb the operations of the network. For ad hoc
networks, till now many secured routing protocols have been proposed which
contains some disadvantages. Therefore security in ad hoc networks is a
controversial area till now. In this paper, we proposed a Lightweight and
Attack Resistant Authenticated Routing Protocol (LARARP) for mobile ad hoc
networks. For the route discovery attacks in MANET routing protocols, our
protocol gives an effective security. It supports the node to drop the invalid
packets earlier by detecting the malicious nodes quickly by verifying the
digital signatures of all the intermediate nodes. It punishes the misbehaving
nodes by decrementing a credit counter and rewards the well behaving nodes by
incrementing the credit counter. Thus it prevents uncompromised nodes from
attacking the routes with malicious or compromised nodes. It is also used to
prevent the denial-of-service (DoS) attacks. The efficiency and effectiveness
of LARARP are verified through the detailed simulation studies.Comment: 14 Pages, IJWM
Compensation of distributed delays in integrated communication and control systems
The concept, analysis, implementation, and verification of a method for compensating delays that are distributed between the sensors, controller, and actuators within a control loop are discussed. With the objective of mitigating the detrimental effects of these network induced delays, a predictor-controller algorithm was formulated and analyzed. Robustness of the delay compensation algorithm was investigated relative to parametric uncertainties in plant modeling. The delay compensator was experimentally verified on an IEEE 802.4 network testbed for velocity control of a DC servomotor
End-To-End Latency of a Fault-Tolerant CORBA Infrastructure
This paper presents an evaluation of the end-to-end latency of a fault-tolerant CORBA infrastructure that we have implemented. The fault-tolerant infrastructure replicates the server applications using active, passive and semi-active replication, and maintains strong replica consistency of the server replicas. By analyses and by measurements of the running fault-tolerant infrastructure, we characterize the end-to-end latency under fault-free conditions. The main determining factor of the run-time performance of the fault-tolerant infrastructure is the Totem group communication protocol, which contributes to the end-to-end latency primarily in two ways: the delay in sending messages and the processing cost of the rotating token.
To reduce the delay in sending messages for passive and semi-active replication, the position of the primary server replica on the Totem ring, the token rotation time, the processing time at the client, and the processing time at the server must be considered. For active replication, the presence of duplicate messages adversely affects the performance. However, if an effective sending-side duplicate suppression mechanism is implemented, active replication is more advantageous than both passive and semi-active replication because of the automatic selection of the most favorable position of the server replica that sends the first non-duplicate reply
Digital system bus integrity
This report summarizes and describes the results of a study of current or emerging multiplex data buses as applicable to digital flight systems, particularly with regard to civil aircraft. Technology for pre-1995 and post-1995 timeframes has been delineated and critiqued relative to the requirements envisioned for those periods. The primary emphasis has been an assured airworthiness of the more prevalent type buses, with attention to attributes such as fault tolerance, environmental susceptibility, and problems under continuing investigation. Additionally, the capacity to certify systems relying on such buses has been addressed
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