  We study propagation and on-off switching of two colliding soliton sequences
in the presence of second-order dispersion, Kerr nonlinearity, linear loss,
cubic gain, and quintic loss. Employing a Lotka-Volterra (LV) model for
dynamics of soliton amplitudes along with simulations with two perturbed
coupled nonlinear Schr\"odinger (NLS) equations, we show that stable
long-distance propagation can be achieved for a wide range of the gain-loss
coefficients, including values that are outside of the perturbative regime.
Furthermore, we demonstrate robust on-off and off-on switching of one of the
sequences by an abrupt change in the ratio of cubic gain and quintic loss
coefficients, and extend the results to pulse sequences with periodically
alternating phases. Our study significantly strengthens the recently found
relation between collision dynamics of sequences of NLS solitons and population
dynamics in LV models, and indicates that the relation might be further
extended to solitary waves of the cubic-quintic Ginzburg-Landau equation.
