The problem of assigning

carrier frequencies so as to avoid certain types (third and fifth order) of intermodulation interference is discussed. For the third-order case, close upper and lower bounds on the optimal solution are established; and close to optimal solutions are given for

(previously, suboptimal solutions were known only for

). For the fifth-order case, it is shown that some existing results can be applied to this problem, and suboptimal solutions obtained by this construction are given for

(no solutions were known previously).