In a heterogeneous network with a shared cell-ID, the current power control mechanism only configures common power control parameters for all UE in a macro cell, and this doesn’t match the receiving power of a wireless access point associated actually, and may lead to serious interferences. The insert grip includes a plurality of tubular flexible inserts, each having a tubular body extending through one of the openings. A memory, such as a shift register, may be used to store and then grayscale levels to be written to adjacent pixels are compared and if a difference between these grayscale levels exceed a certain value then at least one of the grayscale levels is modified. The alarm may be acoustic or optic.