Two types of commutation signaling for combating multipath are introduced:

signaling, in which the signal set cycles successively among

different sets of

sigals each; and

signaling, in which the signal set at any time consists of

members of an alphabet of

signals,

of which are inactive at any epoch. In both cases, the objective is to remove from use any signal sent recently enough that it is still "ringing" in the multipath channel. We consider the problems of minimization of

and

, hence the total number signals used; analysis of

sets (

is almost uniformly optimal); analysis of the simplest

set, i.e., a 2 + 1 set; and presentation of the results of simulation of

and

signaling through realistic urban/suburban radio channels. Comparison of these simulations to simulations of other antimultipath techniques is also made. The simulation results are due to Kamil [3].