Jae-il Jung

WAP: Wormhole Attack Prevention Algorithm in Mobile Ad Hoc Networks

In wireless ad hoc networks, nodes compromise to forward packets for each other to communicate beyond their transmission range. Therefore, networks are vulnerable to wormhole attacks launched through compromised nodes because malicious nodes can easily participate in the networks. In wormhole attacks, one malicious node tunnels packets from its location to the other malicious node. Such wormhole attacks result in a false route with fewer. If source node chooses this fake route, malicious nodes have the option of delivering the packets or dropping them. It is difficult to detect wormhole attacks because malicious nodes impersonate legitimate nodes. Previous algorithms detecting a wormhole require special hardware or tight time synchronization. In this paper, we develop an effective method called wormhole attack prevention (WAP) without using specialized hardware. The WAP not only detects the fake route but also adopts preventive measures against action wormhole nodes from reappearing during the route discovery phase. Simulation results show that wormholes can be detected and isolated within the route discovery phase.

Translation of QoS parameters into ATM performance parameters in B-ISDN

The quality of service (QoS) concept for broadband ISDN (B-ISN) is studied. The QoS parameters in the asynchronous transfer mode (ATM) layer and the AAL (ATM adaptation layer) are defined. The focus is on the translation of QoS parameters between layers, particularly from the AAL to the ATM layer, because the AAL must be designed to be service dependent and specific. The QoS parameters at the ATM layer resulting from the translation will be the performance requirements on a connection basis for the ATM network. The impact of QoS parameter translation on guaranteeing QoS in the ATM network is discussed.<<ETX>>

Vehicular Multi-Hop Broadcasting Protocol for Safety Message Dissemination in VANETs

Most safety-related applications targeting at Vehicular Ad-hoc Networks (VANETs) use Vehicle-to- Vehicle (V2V) broadcast method to disseminate safety- related information to all surrounding vehicles. However, the conventional broadcast schemes have the broadcast storm problem which can lead to unbearable transmission delay and packet loss. In this paper, we present an efficient broadcast scheme referred as Vehicular Multi-hop broadcasting Protocol (VMP) for fast dissemination of safety message within the critical area. The core of the VMP is that it designates multiple reliable forwarders with differentiated forwarding delay, and exploits cooperative forwarding mechanism to help the forwarding when the specified forwarders fail to transmit the alert message. With the realistic simulation studies, the VMP demonstrates better performance than previous contention-based schemes by reducing end-to-end delay and message rebroadcasting ratio while keeping high message reception rate.

Context awareness beacon scheduling scheme for congestion control in vehicle to vehicle safety communication

Abstract Vehicle safety applications based on vehicle to vehicle communication typically transmit safety-related beacons to all neighboring vehicles with high reliability and a strict timeline. However, due to high vehicle mobility, dynamic network topology and limited network resource, this periodic beaconing could lead to congestion in the communication network. Therefore, beacon transmission method has a special challenge to efficiently use the limited network resources to satisfy the requirements of safety applications. With this motivation, we propose a novel distributed beacon scheduling scheme referred to as the context awareness beacon scheduling (CABS) which is based on spatial context information dynamically scheduling the beacon by means of TDMA-like transmission. The proposed beacon scheduling scheme was evaluated using different traffic scenarios within both a realistic channel model and IEEE 802.11p PHY/MAC model in our simulation. The simulation results showed that the performance of the CABS scheme was better than periodic scheduling in terms of packet delivery ratio and channel access delay. Also, the CABS scheme satisfies the requirements of the safety applications.

Quality of service in telecommunications. I. Proposition of a QoS framework and its application to B-ISDN

The the quality of service (QoS) concept is becoming an ever more important issue in telecommunication and computer communication. The article focuses on the QoS notion and concept. The definition of QoS in the International Telecommunications Union-Telecommunications Sector (ITU-T) recommendations and the International Standards Organization (ISO) standards is analysed. Little is known about the asynchronous transfer mode (ATM) performance requirements of the broadband integrated services digital network (B-ISDN) services, especially for multimedia applications. This is because the ATM performance requirements of multimedia applications depend not only on the diverse QoS requirements from application and user, but also on the protocol stacks and scheduling in end systems. Therefore, in order to guarantee QoS to the user, it is necessary to introduce a set of QoS parameters whose properties indicate the nature and requirements of the layered protocol stack. We describe how a proposed QoS framework can be applied to B-ISDN as a specific network. The QoS aspects related to B-ISDN signaling (the control plane) and the QoS aspects related to layer and plane management (the management plane) are described. We also describe how the QoS framework resides in a protocol stack and works together with the B-ISDN network management and signaling.

Verification and conformance test generation of communication protocol for railway signaling systems

Verification and testing are complementary techniques that are used to increase the level of confidence in the correct functioning of communication systems as prescribed by their specifications. This paper presents an experience of model checking for Korean railway signaling protocol specified in LTS (Labeled Transition System). This formal approach checks deadlock, livelock and reachability for the state and action to verify whether properties expressed in modal logic are true on specifications. We also propose a formal method for semi-automated test case generation for Korean railway signaling protocol described in I/O FSM (Input/Output Finite State Machine). This enables the generation of more complete and consistent test sequence for conformance testing. The above functions are implemented by C++ language and included within RSPVTE (Railway Signaling Protocol Verification and Testing Environment) in the MS-windows environment.

Multi-Stage Intrusion Detection System Using Hidden Markov Model Algorithm

Intrusion detection systems are the basis of system protection from network attacks. However, intrusions are increasingly taking multi-stage procedures to attack a system, and cannot be detected by existing single stage intrusion detection systems. This paper proposes a multi-stage intrusion detection system architecture using hidden Markov model algorithm. This system considers every stage used by recent intrusions and applies them to the hidden Markov model algorithm to determine which intrusion is used in the audit data. This architecture reduces overheads of intrusion agents and raises efficiency of the whole system.

MMAC: an efficient wmATM MAC for multicast communications

Some future broadband multimedia services will require special wireless network features. Especially, the higher the bandwidth each mobile terminal (MT) requires, the more important the capability of multicasting in the radio part comes to be. Legacy wmATM (wireless mobile ATM) MACs have not efficiently supported multicast services. In this paper, we propose an efficient multicast mechanism for the wmATM MAC layer, named MMAC (multicast MAC). We design the system architecture of MMAC, MAC frame format and slot structure. We adopt GSA (group selection agent) by which base stations can reasonably perform the multicast connection admission control and resource allocation in terms of three factors: service classes (e.g., CBR, VBR, ABR/UBR), the number of group members and the requested bandwidth for the multicast channels. Another essential feature of MMAC is to support heterogeneous QoS demand of each MT by filtering cells. This cell filtering is performed by a cell-filter module. On error recovery, one backup channel is used for all multicast channels. Its size is dynamically allocated according to the condition of MMAC. Finally we give a performance evaluation of MMAC by using the OPNET network simulator.

Voting structures for cascaded triple modular redundant modules

This paper investigates what kinds of choices exist in determining the voting structure for cascaded triple modular redundant (TMR) modules, how to identify efficient voting structures, and the effects of voting structures on the overall system reliability. While the classic single-voter and three-voter architectures have been used for about fifty years, the paper shows that there are more practically useful voting structures which provide efficient trade-offs between hardware overhead and system reliability. Specifically, a single-voter architecture with the voter fanout of one is found to be more reliable than the classic single-voter architecture for a reasonably wide range of component reliability.

A RWA Algorithm for Differentiated Services with QoS Guarantees in the Next Generation Internet based on DWDM Networks

A major challenge in next generation Internet (NGI) backbone networks based on dense-wavelength division multiplexing (DWDM) is the provision of guaranteed quality-of-service (QoS) for a wide variety of multimedia applications. This paper proposes a new routing algorithm called multi-wavelength minimum interference path routing (MW-MIPR) to provide more reliable QoS guarantees by consideration of the potential future networks congestion status. This improves wavelength utilization by choosing a route that does not interfere too much with potential future connection requests. Moreover, we introduce a differentiated routing and wavelength assignment (RWA) mechanism combined with recovery strategy and the proposed MW-MIPR algorithm based on the differentiated service model in the NGI. Simulation results show that the proposed MW-MIPR algorithm achieves a smaller blocking probability than dynamic routing (DR) that yields the best performance among previous RWA algorithms. And we prove that a differentiated RWA combined with a recovery capability together with the proposed routing scheme provides satisfied QoS assurance for each service class in terms of signal quality and survivability.