▁that ▁service ▁to ▁be ▁available . ▁ ▁The ▁cell ▁service ▁level ▁indicates ▁that ▁the ▁neighbour ▁cell ▁is ▁less ▁loaded ▁than ▁the ▁serving ▁cell . ▁ ▁Cell ▁rel in qu ish able ▁( ab andon able ) ▁▁ ▁The ▁next ▁diagram ▁illustr ates ▁where ▁a ▁given ▁T ET RA ▁radio ▁cell ▁becomes ▁rel in qu ish able ▁( ab andon able ). ▁The ▁serving ▁cell ▁becomes ▁rel in qu ish 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 , ▁fast ▁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 , ▁fast ▁res elect ▁h yst er esis , ▁for ▁a ▁period ▁of ▁ 5 ▁seconds . ▁ ▁No ▁successful ▁cell ▁res e lection ▁shall ▁have ▁taken ▁place ▁within ▁the ▁previous ▁ 1 5 ▁seconds ▁unless ▁M ob ility ▁Management ▁( MM ) ▁requests ▁a ▁cell ▁res e lection . ▁The ▁MS - M LE ▁shall ▁check ▁the ▁criter ion ▁for ▁serving ▁cell ▁rel in qu ishment ▁as ▁often ▁as ▁one ▁neighbour ▁cell ▁is ▁sc anned ▁or ▁monitor ed . ▁ ▁Radio ▁down - link ▁failure ▁▁ ▁When ▁the ▁F RT ▁threshold ▁is ▁bre ached , ▁the ▁MS ▁is ▁in ▁a ▁situation ▁where ▁it ▁is ▁essential ▁to ▁rel