readme

传感器网络中的嵌入式操作系统源代码

This is a drop-in replacement for TOSSIM's radio stack that operates at
the packet, rather than the bit, level. In preliminary testing it
performs about 100 times faster than the default bit-level radio stack.
Obviously it does not capture the subtleties and behavior of the
bit-level simulation, but, it is useful for testing and simulating large
networks. 

To use this code, all you need to do is add the line
  PFLAGS = -I$(BASEDIR)/tos/platform/pc/packet
to your application Makefile, then rebuild your application with 'make pc'.

This packet-level simulation is compatible with TOSSIM's lossy radio
models, so if you are using "-r lossy" or setting link-level loss
probabilities with TinyViz, it will work.

Currently, the component does not model packet collisions (e.g., the
hidden terminal problem), MAC contention, or variable transmission
time due to these effects or packet length. Packet transmission takes
1/40th of a second, based on the empirical observation that the mica
radio stack can handle about 40 packets/s. Some rough tests indicate
that packet loss rates due to bit errors from the packet-level model
are roughly equal to those in the bit-level model.

Please note, while using this component will tremendously increase the
rate of simulation, its ignorance of the hidden terminal problem
really makes it of little use for anything approaching evaluation in
any meaningful context.


Matt Welsh - [e-mail]
Philip Levis - [e-mail]