▁selection ▁of ▁a ▁cell . ▁ ▁At ▁mobile ▁switch ▁on , ▁the ▁mobile ▁makes ▁its ▁initial ▁cell ▁selection ▁of ▁one ▁of ▁the ▁base ▁stations , ▁which ▁indicates ▁the ▁initial ▁ex changes ▁at ▁activation . ▁▁ ▁Refer ▁to ▁EN ▁ 3 0 0 ▁ 3 9 2 ▁ 2 ▁ 1 6 . 3 . 1 ▁Activ ation ▁and ▁control ▁of ▁underlying ▁M LE ▁service ▁ ▁Note ▁ 1 8 . 5 . 1 2 ▁Min imum ▁R X ▁access ▁level ▁ ▁The ▁minimum ▁receive ▁access ▁level ▁information ▁element ▁shall ▁indicate ▁the ▁minimum ▁received ▁signal ▁level ▁required ▁at ▁the ▁Sw MI ▁in ▁a ▁cell , ▁either ▁the ▁serving ▁cell ▁or ▁a ▁neighbour ▁cell ▁as ▁defined ▁in ▁table ▁ 1 8 . 2 4 . ▁ ▁Cell ▁improv able ▁▁ ▁The ▁next ▁diagram ▁illustr ates ▁where ▁a ▁given ▁T ET RA ▁radio ▁cell ▁becomes ▁improv able . ▁The ▁serving ▁cell ▁becomes ▁improv able ▁when ▁the ▁following ▁occurs : ▁the ▁C 1 ▁of ▁the ▁serving ▁cell ▁is ▁below ▁the ▁value ▁defined ▁in ▁the ▁radio ▁network ▁parameter ▁cell ▁res e lection ▁parameters , ▁slow ▁res elect ▁threshold ▁for ▁a ▁period ▁of ▁ 5 ▁seconds , ▁and ▁the ▁C 1 ▁or ▁C 2 ▁of ▁a ▁neighbour ▁cell ▁exceed s ▁the ▁C 1 ▁of ▁the ▁serving ▁cell ▁by ▁the ▁value ▁defined ▁in ▁the ▁radio ▁network ▁parameter ▁cell ▁res e lection ▁parameters , ▁slow ▁res elect ▁h yst er esis ▁for ▁a ▁period ▁of ▁ 5 ▁seconds . ▁ ▁Cell ▁us able ▁▁ ▁The ▁next ▁diagram ▁illustr ates ▁where ▁a