Abstract
Establishing incoming calls plays an important role in multi-tier networks. In a multi-tier network, if a mobile station (MS) wants to move between different tiers, it has to register at its corresponding tier and deregister at current tier. The registration and deregistration procedures are implemented by network and radio signals. In addition, delivery of an incoming call to the corresponding tier, according to the type of call and the registration area (RA) of the mobile station, consumes power and energy. Many schemes like power efficient single registration (PSR), power efficient multiple registration (PMR) and efficient power management (EPM) have been introduced to reduce the power and energy consumptions of multi-tier networks. In this paper, we introduce a new approach to reduce the energy and power consumptions of multi-tier networks. This new approach is called the optimal power efficient management (OPEM) scheme that uses the advantages of both PMR and PSR in signaling concept. The OPEM scheme introduces a new, different and simple method to reduce the energy consumption of multi-tier networks, especially in two-tier and three-tier networks. The numerical results confirm the preference of the OPEM scheme.