Various arrangements for using different air interfaces on adjacent frequency channels for side-link communications are presented. A first side-link channel may be split into a first bandwidth portion and the second bandwidth portion, in which the first bandwidth portion of the first side-link channel is directly adjacent to the second side-link channel. A first subcarrier spacing may be assigned to the first bandwidth portion of the first side-link channel. The second side-link channel may also use the first subcarrier spacing. A second subcarrier spacing may be assigned to the second bandwidth portion of the first side-link channel that differs from the first subcarrier spacing.