Bugzilla – Bug 1064
Correct Friis propagation loss equation in spectrum module
Last modified: 2011-03-01 12:02:22 UTC
The implementation of Friis' propagation loss equation in the spectrum module is incorrect. Currently, the comment in friis-spectrum-propagation-loss.h agrees with the implementation in friis-spectrum-propagation-loss.cc in indicating that the free space path loss is computed thus: /* L = (4 * pi * d * f^2) / C^2 */ double loss = ( d * f * f) / ((3e8 * 3e8) / (4 * M_PI)) ; These are both wrong - the entire numerator in the comment above should be squared, rather than just the frequency term. The fix I propose can be seen as changeset 6814:d5863a7ab817 in http://code.nsnam.org/deanarm/ns-3-dev-wifi-spectrum
whoops... I wonder how I could write that... what a shame! Thanks for catching it, I am fine with your proposed changeset: http://code.nsnam.org/deanarm/ns-3-dev-wifi-spectrum/rev/d5863a7ab817
Fixed in changeset 6846:8cbf95884984 on ns-3-dev.