Four-Bit Wireless Link Estimation
Rodrigo Fonseca (UCB), Omprakash
Gnawali (USC), Kyle Jamieson (MIT),
and Philip Levis (Stanford)
Summary: Rodrigo highlighted the importance of estimating wireless link
The estimators use information from various layers, and are many a
with platforms or radios.
The talk attempts to highligh what information is available at
define an interface, and implementation.
Physical layer exposes bit decoding errors, link layer exposes the
packet delivery rate, and on the network layer can provide information
which links are useful in terms of "utitlity" from say routing
Rodrigo also described the interface and implementation. He
how ACK is used to fine-tune the estimates.
Q: On slide 8, Why are you using just one bit from phy, when it
provides much richer information.
Ans: We were looking for simplest useful interface.
Q: I am not convinced why phy layer information is not
A: There could be intelligence in higher layers that can help us.
Q: In an ideal world, should not the higher layer information
A: That is a good question; it might be redundant on links where you
already have sent the traffic and learned what the behavior is. But for
links it is useful.
Q: If you are not memory constrained, would you mind keeping
information about all the links?
A: That is true, however our focus is sensor applications where memory
Q: What is the take away;
A: The interface has to be narrow to be portable.