Alternative metrics for hard handoffs in mobile communication

Abstract

Handoff (or handover) refers to a crucial effort by a particular mobile unit to change from its serving base station to another as warranted by dynamic variations in link quality caused by mobility and interference/fading considerations. Classically, the handover initiation is done by a decision algorithm based on received signal strengths (RSSs) from the serving and prospective base stations. That is, the power difference of the received signal is used as a metric for handoff initiation. Very rapid switching between the two base stations could take place, especially when the mobile unit moves along a cell boundary. To prevent or reduce that effect, this study demonstrates a new algorithmic approach wherein the hard handoff decision is performed by computing the "statistical distance" between two received signal strengths. That is, a set of information-theoretic (IT) based distance measures obtained from the statistics of the RSSs is indicated as alternative metrics for hard handoff efforts.