Disclosed is a single step continuous hydrogenation process for the preparation of 3-methyl-tetrahydrofuran from alpha-methylene-gamma-butyrolactone, in the presence of a catalytic metal. At least one upper wing member guide and at least one lower wing member guide is provided. When the service switching point puts a call on hold, the service switching point connects the call through the permanent trunk line to the service logic program that is playing the continuous tone. The transmitted and received signal strength levels can be used by the mobile station to estimate the amount of intercell interference that the mobile station’s uplink transmissions cause, and the mobile station’s uplink transmission parameters are adjusted accordingly. The decision block provides an output that is at a same logic level as a previous output of the decision block if the two data inputs are not at expected logic levels during normal operating conditions.