????? ????? ???? ??????????? ???????? ???? ?? ????? ???? ? ?????? ????. A ????? ?? ????? ???? ? area ????? ???? ???? can ??????? ??????? ??? ????. ??????? ????? features relatively ??????? ????? ????? ??? ??????? ? network ?????? ??? ???????? ????? ??? ?? ??????? ????? ????? ??????. ?? ?????? ????? and capacity ????? ?? ???? many ???? ???. * ??? ??