Protocol misbehavior detection framework using machine learning classification in vehicular Ad Hoc networks

Wireless Networks - A novel approach is proposed to detect protocol misbehavior using state-of-the-art machine learning frameworks and entropy. Nodes in Vehicular Ad Hoc Networks (VANETs) use...     

Processor scheduling and allocation for 3D torus multicomputersystems

Multicomputer systems achieve high performance by utilizing a number of computing nodes. Recently, by achieving significant reductions in communication delay, the three-dimensional (3D) torus has emerged as a new candidate interconnection topology for message-passing multicomputer systems. In this paper, we propose an efficient processor allocation scheme-scan search scheme-for the 3D torus based on a first-fit approach. The scan search scheme minimizes the average allocation time for an incoming task by effectively manipulating the 3D information on a torus as 2D information using a data structure called the CST (Coverage Status Table). Comprehensive computer simulation reveals that the allocation time of the scan search scheme is always smaller than that of the earlier scheme based on a best-fit approach. The difference gets larger as the input load increases, and it is as much a factor of 3 for high load. To investigate the performance of the proposed scheme in different scheduling environments, we also consider a non-FCFS scheduling policy along with the typical FCFS policy. The allocation time complexity of the scan search scheme is O(LW²H²). This is significantly smaller than that of the existing scheme which is O(L⁴W⁴H⁴). Here, L, W, and H represent the length, width, and height of 3D torus, respectively     

An efficient task allocation scheme for 2D mesh architectures

Efficient allocation of processors to incoming tasks in parallel computer systems is very important for achieving the desired high performance. It requires recognizing the free available processors with minimum overhead. In this paper, we present an efficient task allocation scheme for 2D mesh architectures. By employing a new approach for searching the mesh, our scheme can find the available submesh without scanning the entire mesh, unlike earlier designs. Comprehensive computer simulation reveals that the average allocation time and waiting delay are much smaller than earlier schemes of comparable performances, irrespective of the size of meshes and distribution of the shape of the incoming tasks     

Timeout Period Analysis to Detect Black Hole Attack in Multihop Wireless Ad Hoc Networks

A novel approach is proposed to estimate the timeout period used in wireless ad hoc networks in order to detect misbehaving nodes that make black hole attacks. Timeout period is an acceptable time frame for a node to forward a packet and is used to judge if the node is behaving properly. To avoid misjudgment and false alarms, the accuracy of the estimate of the timeout period is very important. Our method is based on the IEEE 802.11 MAC protocol and Dynamic Source Routing protocol. The main contribution of this paper is proposing a queuing analysis to calculate the mean and maximum delay per hop implementing the 95-percentile of medium access waiting time. In addition, a new technique is introduced that can be applied to determine the mean number of hops in flooding-based ad hoc networks, taking into account edge effects. For each proposed model, analytical results are compared with results obtained from simulations and the validity of the models is confirmed by observing the close relationship between the results.     

An efficient reliable one-hop broadcast in mobile ad hoc networks

A reliable one-hop broadcast is a fundamental communication primitive in mobile ad hoc networks in which a message from the source node is guaranteed to be delivered to all nodes within the source node’s transmission range. Despite the importance of it, reliable one-hop broadcast is not easy to accomplish due to collisions in wireless networks known as Hidden Terminal Problem. This paper presents a MAC protocol that not only guarantees reliable one-hop broadcast but also achieves it efficiently by exploring as many simultaneous executions of the communication as possible. In addition to the data packets, the proposed algorithm utilizes the control packets that prevent packet collisions, and at the same time, make the simultaneous communications possible to improve the network throughput. Simulation results show the effectiveness of the proposed algorithm.     

Multi-user data multiplexing for digital multimedia broadcasting

Recently, a Korean standard service, as the designated digital multimedia broadcasting (DMB) system, has been in commercial service following a period of time of careful reflection. Now, the next generation of digital broadcast services will not be limited to digital audio but also extended to a variety of multimedia data services as well as mobile application services. However, the current approaches for transporting multimedia content over wireless networks for the DMB require significant overhead. In this paper, we propose a new approach for multi-user data multiplexing with several access points serving a number of wireless terminals for the DMB. By modifying the multiplexer header, multiplexing time, and handling of time-critical data, the duplication overhead can be considerably decreased when compared to existing schemes.     

E2EACK: an end-to-end acknowledgment-based scheme against collusion black hole and slander attacks in MANETs

Mobile ad hoc networks (MANETs) rely on the benevolence of nodes within the network to forward packets from a source node to a destination node. This network construction allows for the forwarding nodes, whether they are selfish or malicious, to drop packets hindering end-to-end communication. In this paper, a new scheme is proposed against collusion black hole and slander attacks in MANETs, named E2EACK. A novel method is used to detect collusion attacks due to collusive malicious nodes which cooperate in the route discovery, but refuse to forward data packets and do not disclose the misbehavior of each other. Contrary to existing methods that detect only collusion black hole attacks, the E2EACK also detects slander attacks and framing attacks. Moreover, the E2EACK uses ACKnowledgment packet to detect malicious nodes on the path and Message Authentication Code (MAC) to authenticate the sender of each data packet. Analytical and simulation results show that the proposed scheme considerably decreases the routing overhead and increases the packet delivery ratio compared to the existing methods.