J. Wozniak et al. (Eds.): WMNC 2009, IFIP AICT 308, pp. 321–331, 2009. © IFIP International Federation for Information Processing 2009 The Efficiency Performance on Handover's Scanning Process of IEEE802.16m Ardian Ulvan and Robert Bestak Czech Technical University in Prague, Faculty of Electrical Engineering, Technicka 2, Prague, 16627, Czech Republic {ulvana1,bestar1}@fel.cvut.cz Abstract. This paper investigates the efficiency of scanning process on hand- over procedure in IEEE802.16m. The performance evaluation is based on cur- rent running standard of 802.16e since .16m is still under development. The evaluation is done at both parts of handover procedure, i.e. network topology acquisition and handover process. An efficient scanning process is proposed to reduce the scanning time and obtained a minimal handover interruption time. Keywords: WiMAX network, handover, MAC efficiency. 1 Introduction The IEEE 802.16m amends the IEEE802.16 WirelessMAN-OFDMA specification to provide an advanced air interface for operation in licensed frequency bands. It includes enhancements and extensions to the IEEE STD 802.16e to meet the cellular layer re- quirements of IMT-Advanced next generation mobile networks conducted by Interna- tional Telecommunications Union – Radio Communications Sector (ITU-R) [1]. The handover is an integral part of all mobile wireless systems. Continuous con- nection during user movement among cells is allowed due to handover procedure, but on the other hand, the handover brings a significant increase of Medium Access Con- trol (MAC) overhead and also causes an increase in delay of packet delivery to the destination user. The handover WiMAX is introduced in the latest version of IEEE802.16e [2]. Based on the emerging 802.16j proposals, it is very probable that in the next versions of WiMAX recommendations (IEEE 802.16j, and IEEE 802.16m) will be defined the same types of handovers. Moreover, the general principles (with regards to the re- quirements of new standards) of handover will be adopted from 802.16e. The handover issues on IEEE802.16 have been carried out in several literatures. The fast handover in IEEE802.16e is analyzed in [3]. The single neighbor BS scan- ning, fast ranging and pre-registration have been proposed to reduce the handover time. To decrease hard handover, the authors in [4] propose handover modification that makes possible to receive downlink data just after synchronization with downlink channel of the target Base Station (BS). This is achieved by introducing a new MAC management message – Fast DL_MAP_IE message, which describes the fast downlink access definition in system’s information element. This message is used for