Location Management in Mobile Ad Hoc Wireless Networks Using Quorums and Clusters

Position-based reactive routing is a scalable solution for routing in mobile ad hoc networks. The route discovery algorithm in position-based routing can be efficiently implemented only if the source knows the current address of the destination. In this paper, a quorum-based location management scheme is proposed. Location servers are selected using the minimum dominating set (MDS) approach, and are further organized into quorums for location update and location query. when a mobile node moves, it updates its location servers in the update quorum; when a node requests the location information of another node, it will send a query message to the location servers in the query quorum. We propose to use the position-based quorum system, which is easy to construct and guarantees that the update quorums always intersect with the query quorums so that at least one location server in the query quorum is aware of the most recent location of the mobile node. Clusters are introduced for large scale ad hoc networks for scalability. Experiment results show that the proposed scheme provides good scalability when network size increases

Mengenal pasti masalah pemahaman dan hubungannya dengan latar belakang matematik, gaya pembelajaran, motivasi dan minat pelajar terhadap bab pengawalan kos makanan di Sekolah Menengah Teknik (ert) Rembau: satu kajian kes.

Kajian ini dijalankan untuk mengkaji hubungan korelasi antara latar belakang Matematik, gaya pembelajaran, motivasi dan minat dengan pemahaman pelajar terhadap bab tersebut. Responden adalah seramai 30 orang iaitu terdiri daripada pelajar tingkatan lima kursus Katering, Sekolah Menengah Teknik (ERT) Rembau, Negeri Sembilan. Instrumen kajian adalah soal selidik dan semua data dianalisis menggunakan program SPSS versi 10.0 untuk mendapatkan nilai min dan nilai korelasi bagi memenuhi objektif yang telah ditetapkan. Hasil kajian ini menunjukkan bahawa hubungan korelasi antara gaya pembelajaran pelajar terhadap pemahaman pelajar adalah kuat. Manakala hubungan korelasi antara latar belakang Matematik, motivasi dan minat terhadap pemahaman pelajar adalah sederhana. Nilai tahap min bagi masalah pemahaman pelajar, latar belakang Matematik, gaya pembelajaran, motivasi dan minat terhadap bab Pengawalan Kos Makanan adalah sederhana. Kajian ini mencadangkan penghasilan satu Modul Pembelajaran Kendiri bagi bab Pengawalan Kos Makanan untuk membantu pelajar kursus Katering dalam proses pembelajaran mereka

Upgraded Scalable Virtual Treebased Multicast Routing Protocol for Secured Packet forwarding in MANET's

ABSTRACT: Now a day's Mobile ad-hoc networks became a popular subject for research due to its wide utilization in different areas, and various studies have been made to increase the performance of ad hoc networks and support more advanced mobile computing and applications. Multicasting is a useful operation that facilitates group communications in MANETs. There are some problems of the existed mobile computing applications are multicast group membership management, zone construction and efficient forwarding of packets to all the group members over the dynamic network topology for a large group size or network size. This paper concentrated specifically, on efficient packet forwarding through a virtual-zone-based structure, and the location service for group members is integrated with the membership management. Both the control messages and data packets are forwarded along efficient tree-like paths, but there is no need to explicitly create and actively maintain a tree structure. The stateless virtual-tree-based structures significantly reduce the tree management overhead, support more efficient transmissions, and make the transmissions much more robust to dynamics. By upgrading the USVGM protocol with virtual-zone-based structure and tree-like paths we achieved higher performance and reliable and scalable data packet forwarding. Our simulation results demonstrate that Upgraded SVGM (USVGM) has high packet delivery ratio, low control overhead and multicast group joining delay under all test scenarios, and is scalable to both group size and network size. Keywords: USVGM, LAM, MZRP, LGT, LGS I. INTRODUCTION MANET is a collection of wireless nodes that can dynamically be set up any where and anytime without using any preexisting network infrastructure. It is an autonomous system in which mobile hosts connected by wireless links are free to move randomly and often act as routers at the same time. The traffic types in ad hoc networks are quite different from those in an infrastructure wireless network. Due to its popularity and wide advantages MANET are applied to different applications including battlefield communications, emergency relief scenarios, law enforcement, public meeting, virtual class room and other security-sensitive computing environments. Multicasting is a powerful scenario in MANET's environment. The design of the multicast scheme in MANET is more complex because of the dynamic change in the network topology and the limited bandwidth availability. Previous researches designed some ad hoc network routing protocols LAM [3], MZR

A survey of self organisation in future cellular networks

This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks

A Survey on Wireless Sensor Network Security

Wireless sensor networks (WSNs) have recently attracted a lot of interest in the research community due their wide range of applications. Due to distributed nature of these networks and their deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. This problem is more critical if the network is deployed for some mission-critical applications such as in a tactical battlefield. Random failure of nodes is also very likely in real-life deployment scenarios. Due to resource constraints in the sensor nodes, traditional security mechanisms with large overhead of computation and communication are infeasible in WSNs. Security in sensor networks is, therefore, a particularly challenging task. This paper discusses the current state of the art in security mechanisms for WSNs. Various types of attacks are discussed and their countermeasures presented. A brief discussion on the future direction of research in WSN security is also included.Comment: 24 pages, 4 figures, 2 table