tailieunhanh - Handbook of Wireless Networks and Mobile Computing phần 9

Vk là khác biệt, và trong đó có ít nhất một vi như vậy mà m (vi) = F (nếu không, v và u kết nối trong G). Mặt khác, hai đỉnh liền kề của vi, vi-1 và vi +1, không kết nối trong G, nếu không, (v, v1, v2, vk, u) không phải là một con đường ngắn nhất. Vì vậy, m (vi) = T dựa trên quá trình đánh dấu. Điều này mang đến một mâu thuẫn. | 500 MULTICASTING FROM FIXED NETWORKS TO AD HOC NETWORKS either the current MF of the MA or the MF of the visiting mobile node. Both the MA and the mobile node replace their MF value with the newly selected MF. From the point of the multicast tree a MA extends the tree from an MF among adjacent networks that belong to the multicast delivery tree for the group. Because the mobility of mobile nodes is expected to show locality characteristics this MF is one of the more adjacent multicast tree nodes from the current network. Comparing these proposals the multicast tree in the foreign-agent based proposal is die mostuptimalone. But frequentmovementreqmresfrequent reconfigurations of the multicast tree. This puts a high load on the multicast routers. The MMA proposal has the second-besttree mdnnt everymovementwillcause themulticasttreeto change. Itthere-fore providesgoodmulticast syp VM tS rnatl vn. eveọu feaetgo neOooek Uat iobepioyMAs. Allike-e ickemetassumetypUPemobilelioti iiliwsi onc-vii clesthor igvitpfrouithgfixed mfrnslnteiake otìichlsdhasactrTÌstic of crllulrrnntwo-kni Tkegare therefore notrUle iohanVlstruty udhgsneyposks ikwOichmtrrmediatswodetaremobiln eswell. TOUkTICASTING INMOBtOE AD HOC NETWORKSt AVO-TING amiWELESS PROTOCOLS -nmo-ilo oO Ioh network nUereare tlm uTi ic cnIegol iesof ddltin itsinIe dnil. naitUi upyoea-hislo tuiipki fleosIIltc gbtwork. Euefynode I e eniwinioa Cg soidtn O-ooks ittoa bclito neighb i enetwoi k ads iiVe ackoiu reaetioo-ketonn rectth in exponential growth. The proactive approach precomputes paths to all possible destinations and stores this information in routing tables. To maintain an up-to-date database routing information is periodically distributed throughout the network. These protocols isto create paths to other hostrondemMi. TPaidee ishasnd on aaeery-response mechanism or reactive multicast. In the query phase a node explores the .