The routing technology of the self-organizing network is mainly to design a distributed routing protocol that can adapt to the dynamic change of the network topology, avoid routing loops, reduce routing overhead as much as possible, and have certain scalability, so that network nodes can be based on network conditions The change has the routing function of each distributed management. Self-organizing network is a multi-hop temporary autonomous system. In this environment, due to the limited wireless communication coverage of nodes, two mobile nodes that cannot communicate directly can use other nodes to forward packets. Perform data communication. Ad hoc network nodes exchange data through a multi-hop data forwarding mechanism, and need to make packet forwarding decisions according to routing protocols.
Classification of self-organizing network routing protocols by driving mode
So far, the active protocols that have been proposed mainly include WRP and DSDV. The two protocols are briefly described below.
(1) WRP agreement
Wireless routing protocol (wireless routmg protocol, WRP) is a protocol based on distance vector, and its routing algorithm is an improvement to the path discovery algorithm PFA. It uses the path length to the target node and the information from the corresponding path to the penultimate hop node to accelerate the convergence speed of the routing protocol and improve the routing loop problem. The improvement of WRP to PFAD is that when node i detects that the link with neighbor node j changes, i will check the consistency of the information about the penultimate hop of all neighbor nodes, while PFA will only check the node j The consistency of the information about the penultimate node. This improvement can further reduce the number of routing loops and speed up the convergence of the algorithm. The main ideas of the WRP protocol are as follows:
Each node maintains four tables, namely distance table, routing table, link cost table and message re-publishing, and announces to neighbor nodes through UPDATE messages.
Suppose the node is i, the sink node is j, and the neighbor node of node i is k.
â‘ Distance table. The distance table includes the relevant content of the announcement of k, which is Piik, the predecessor node of the distance Dijk passing through the route from k to j.
â‘¡ Routing table. Each entry includes the address of the sink node, the distance Dij to the sink, the shortest route to j from the predecessor node Pij, i's next hop (successor) Sij, and so on.
â‘¢ Link cost table. The link cost through the node and the time since the last error-free message
time.
â‘£The news is republished. It can include multiple re-published items, and each entry includes the sequence number of the update message, the retransmission count, the ACK flag (whether the corresponding ACK has been sent), and the update message list.
WRP achieves reliable transmission by sending ACK, and the node tests the existence of its neighbor nodes by receiving ACK and other messages. If the node does not find a data packet, it periodically sends a HELLO message to obtain connectivity messages with neighbor nodes. If you do not receive any message from a neighbor node within a certain period of time, it is considered that the link with the neighbor node has failed; when there is a new neighbor node, it advertises its routing table to the new node . When the node receives an update message, it uses a route discovery algorithm to update the routing table and overcome the "count to infinity" problem. WRP has improved the route discovery algorithm, and its unique performance is as follows.
①The distance table is updated. For each update message (such as the announcement of k), node i detects all its neighbor nodes {B∈Ni | b ≠k}. For any route passing from node b to j and including the flower node, the distance value is required. Recalculated as Dibj = Dikj + Dij, and the routing predecessor is updated as Pijb = Pkj.
②The routing table is updated. When the neighbor P → J route does not include i and is the shortest route to j among the neighbor nodes, then node i selects neighbor p as its next hop node to j, that is, updates Sij = p.
Srisung Technology Co.,Ltd.,provides various brands feeder,it is not only original new but also used.It can be repaired and tested if it is original and used.In adddtion, any other spare parts for SMT machine also can be found in this company.
Fuji Feeder is in stock for SMT machine for FUJI NXT CP6 CP7 XP242 XP243
FUJI Feeder
Yamaha Smt Feeder
Yamaha Feeder
Smt Feeder For Yamaha
Siemens Smt Feeder
SIEMENS Feeder
Samsung Smt Feeder
FUJI Feeder
Pneumatic Feeder,Fuji Feeder,Fuji Smt Tape Feeder,Smt Fuji Feeder
Shenzhen Srisung Technology Co.,Limited , https://www.sr-smt.com