There is disclosed a runner for a Francis-type hydraulic turbine where each runner blade has an outlet edge with two stress relieving grooves cut through the blade from the outlet edge adjacent the crown and the band. The base has six projecting members to form a container for receiving an IC therein. Therefore, a minimum distance condition between codes of a long code is satisfied and simultaneously the code be simply generated. Additionally or alternatively, some of techniques described herein may facilitate the spreading of the time over which devices attempt to transmit packets, thereby reducing the probability of collisions using, for example, Additive Decrease Multiplicative Increase mechanisms.