GEOCASTING IN MOBILE AD HOC NETWORKS LOCATION- BASED MULTICAST ALGORITHMS 指導教授：許子衡 教授 學生：翁偉傑 1 Young-Bae Ko and Nitin H. Vaidya Department of Computer Science Texas A&M University College Station, TX , USA

OUTLINE Abstract Location-Based Multicast (LBM)Protocols Simulation Optimizations of Location-Based Multicast Conclusion 2

ABSTRACT This paper addresses the problem of geocasting in mobile ad hoc network (MANET) environments. Describes proposed approach for location-based multicasting in MANET. Finally, We present two different algorithms for delivering packets to such a group, and present simulation results. 3

LOCATION-BASED MULTICAST PROTOCOLS (1/5) Multicast Flooding 4 This algorithm would be very simple and robust but would not be very efficient. we attempt to reduce the number of nodes, outside the multicast region. 不理會目的的地區，直接廣播給所有的節點， 每個接收端都會確認自己是不是在目的地區裡。

LOCATION-BASED MULTICAST PROTOCOLS (2/5) Multicast Region and Forwarding Zone 5 Location Information Location information used in our protocol may be provided by the global positioning system (GPS), utilizes location information to reduce multicast delivery overhead.

LOCATION-BASED MULTICAST PROTOCOLS (3/5) Multicast Region and Forwarding Zone 6

LOCATION-BASED MULTICAST PROTOCOLS (4/5) Location-Based Multicast (LBM) Scheme 1 7 Forwarding zone 大小： -destination region -sender location

LOCATION-BASED MULTICAST PROTOCOLS (5/5) Location-Based Multicast (LBM) Scheme 2 8 this protocol ensures that every transmission of data sends the data closer to the destination. LBM Scheme 2: Unlike scheme 1, scheme 2 does not have a forwarding zone explicitly.

SIMULATION (1/4) MaRS( Mary-land Routing Simulator ) Number of nodes in the network was chosen to be 30. The nodes in the mobile ad hoc network are confined to a 1000 unit x 1000 unit square region. Each node moves with an average speed v. 9

SIMULATION (2/4) For the simulations, transmission range values of 200, 250, 300 and 400 units were used. Each simulation run simulated 1000 seconds of execution. We assume that the multicast region is a 300 unit x 300 unit square region. LBM1 和 LBM2 10

SIMULATION (3/4) Simulation Result LBM1 11 較小的傳送路徑，成功率較大

SIMULATION (4/4) Simulation Result LBM2 12 傳輸距離增加， flooding 增加

OPTIMIZATIONS OF LOCATION- BASED MULTICAST (1/4) Alternative Definitions of Forwarding Zone 13 兩種方式定義一個轉發區總是平 行於 X 和 Y 軸 one side of the rectangle may be made parallel to the line connecting the location of source node S to the geometric center of the multicast region.

OPTIMIZATIONS OF LOCATION- BASED MULTICAST (2/4) Forwarding Zone Adaptation 14 location-based multicast scheme 1 ： 調整轉送區

OPTIMIZATIONS OF LOCATION- BASED MULTICAST (3/4) Forwarding Zone Adaptation 15 when the forwarding zone is defined as a cone rooted at node S, such that angle made by the cone is large enough to include the forwarding zone.

OPTIMIZATIONS OF LOCATION- BASED MULTICAST (4/4) Use of Directed Antennas This inherent limitation can be mitigated by using directed antennas whose radiation pattern is not omnidirectional. multicast data packets 多播 數據包只能針對一小群的移 動節點。 16

CONCLUSION We propose two location-based multicast algorithms, limit the forwarding space for a multicast packet to the so-called forwarding zone. Simulation results indicate that proposed algorithms result in lower message delivery overhead, as compared to multicast flooding. it is possible to achieve accuracy of multicast delivery comparable with multicast flooding. 17