The invention is related to a wavelength allocation scheme for a WDM equipment with a distribution of used optical channels that are arranged around a saturation channel in a way that the total spectrum of the optical channels is balanced independent from the number of equipped optical channels. The tool comprises a housing having a gripping portion and a barrel portion, with barrel portion having a front section and a rear section. Also disclosed is a method for accessing a closed subscriber group TA. The user can then group the power distribution units according to their locations or their properties in order to control the on and off thereof. Examples disclosed herein may further relate to determining a subset of wireless transmitters from a plurality of wireless transmitters based at least in part on the expected route of the mobile device. The skeletal substrate includes a three dimensional article, such as a durable corrugated paperboard or other material, with a load supporting and planar upper surface and a recess configured and pallet fork receiving underside.