On Feb 28, 2008, at 1:08 AM, Tao Liu wrote:
Dear all, I am a beginner in TinyOS, and I am trying to understand the routing algorithms used in TinyOS 2. According to the TEP 123, TinyOS 2.0 uses CTP as the routing protocol for multihop communications, which uses ETX as the route metric to estimate the quality of a link. However, my understanding is that TinyOS 2.0 provides two implementations of the CTP: - tos/lib/net/ctp - tos/lib/net/lqi
tos/lib/net/lqi is not an implementation of CTP (TEP 123). It's a collection service (TEP 119), but a completely different protocol.
The first one uses ETX, and the second one uses LQI in the link estimation. Is there any way to incorporate other route metrics to the current CTP implementation? If there is, which component should I modify to apply the new metric? I believe there should be some components in tos/lib/net/le, but I am not sure.
CTP can be used with different link estimators: tos/lib/net/le and tos/lib/net/4bitle are the two in CVS, with the latter being much better.
I am also wondering what are the preferred routing protocols currently used in the wireless sensor networks, especially those protocols that are not tree-based? As far as I can tell TOS 2.x provides two (the ones mentioned above), and TOS 1.x offers more. There are also prototype protocols such as S4 (Small state and Small Stretch Routing Protocol) and CentRoute (CENS) available. Are there any point to point protocols available that are not tree-based?
Please take a look at Om's slides from TTX5. TYMO, a slight variation on DYMO, should be making its way into CVS soon. Note, though, that one-to-one routing which is not tree based has fundamental scaling problems.
Out of the existing sensor network deployments, which routing protocol seems to get the most use? I would appreciate if you could provide pointers to the implementations as well (whether they are on the main TOS code repository or a different one).
Most deployments don't use or need one-to-one routing. Those that do tend to use application-specific approaches, as the general case requires O(n) state.
Phil _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
