Joint collaboration implemented in C using POSIX Threads and OpenMPI. A simulation of a WSN consensus algorithm utilising sensors that communicate with satellites in order to detect bushfires within a particular area.
On initilisation, we create a base station which always exists at the last rank on the MPI network, and wherein the sensor nodes take occupation of all the other ranks in the network. There are some strict specifications to the running of this program as the user specifies command line arguments of the cartesian grid that must follow an n * m form factor. Then, a master (base station) node must be specified. If an n * m + 1 nodes are not specified an informative error ensues and the user must re-specify the parameters given the aforementioned schema.
Another user-specified command line argument is the WSN's communication interval (in seconds). This allows the user to decide the network's polling frequency. This is an important feature as if a bushfire sensor detection network does not have a wired connection, it may rely on solar power or battery power which could cause a fault in the entire network, if the polling frequency were to be too often causing a complete diminution of its power resources.
Also, it should be noted that the user can specify the number of iterations, as a command line argument, that they would like the network to function for. Its total runtime can be calculated by multiplying the interval with the iterations argument. The network proceeds to check for any local consensus of overheated sensor nodes. This means that for a given node that has achieved the threshold temperature (85° C) it sends a request to its adjacent neighbor nodes (the number of requests range between 2 to 4 nodes depending where the sensor node is within the cartesian grid). These packets are then sent back to the node attempting to achieve local overheat consensus whereby the given sensor node checks that at least 2 or more adjacent nodes are greater than the threshold temperature minus 5 (> 85 - 5). If this occurs a (C) structure is sent back to the base station ready to post the detailed event information to the specified log files. If this local consensus does not occur then the packet is never sent and this process continues to repeat. Of course, at the base station these overheat report packets are cross-checked with the satellite sensor to ensure no false positives. If the two temperatures match (from the satellite and the sensor nodes) then it is logged as a 'confirmed report' or otherwise a 'false report'.
Sensor nodes create an IRecv message at the beginning of execution listening for a message tagged BASENODESHUTDOWN. Then, individually, as their final instruction, they will check to see if this message was received. If the message is recieved, each node will run MPI_Finalize, simulating a shutdown. This form of shutdown, termed 'graceful shutdown', prevents final processing of data/memory from being interrupted, such that the WSN can be appropriately shutdown.
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent