In a two-tier microcell/macrocell cellular system, to keep the handoff rate at an acceptable level, low mobility users (with speed v V0) should undergo handoffs at macrocell boundaries. We propose a procedure by which the mobile determines user mobility from microcell sojourn times and uses it for micro-macro cell selection at call origination and handoff. The probability of erroneous assignment of a mobile to a microcell or macrocell is shown to be significantly lower than previous approaches.link_to_subscribed_fulltex