| 摘要 |
A Data Distribution Service (DDS) transfers information between nodes in an ad hoc mobile mesh network. The DDS includes many different novel features including techniques for coalescing retransmit requests to minimize traffic, providing a reasonable level of reliability for event oriented communications, multicasting retransmissions for use by many nodes, and providing other optimizations for multicast traffic. The DDS uses UDP datagrams for communications. Communications operate in a truly peer-to-peer fashion without requiring central authority or storage, and can be purely ad hoc and not depend on any central server. The protocol is NACK-based, which is more suited to a mesh network than a traditional approach like TCP, which uses positive acknowledgements of all data. The DDS is amenable to very long recovery intervals, matching well with nodes on wireless networks that lose coverage for significant periods of time and also works well with constantly changing network topologies. Reliability can also be handled over a span of time that might correspond to losing wireless coverage.
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