ABSTRACT
CONTENTS 6.1 Overview of Mobility-Supporting Functions ....................................... 104 6.2 Power-Saving Mechanism ....................................................................... 105
6.2.1 Power-Saving Class of Type I ..................................................... 106 6.2.2 Power-Saving Class of Type II .................................................... 107 6.2.3 Power-Saving Class of Type III ................................................... 108
6.3 Handover ................................................................................................... 109 6.3.1 Network Topology Acquisition .................................................. 109
6.3.1.1 Network Topology Advertisement ............................. 109 6.3.1.2 Scanning of Neighbor BSs ............................................ 110 6.3.1.3 Association ...................................................................... 111
6.3.2 Basic Handover Operation .......................................................... 114 6.3.2.1 Cell Reselection .............................................................. 115 6.3.2.2 Handover Decision and Initiation ............................... 116 6.3.2.3 Handover Cancellation ................................................. 116 6.3.2.4 Synchronization to Target BS Downlink .................... 116 6.3.2.5 Use of Scanning and Association Results ................... 117 6.3.2.6 Ranging ........................................................................... 117 6.3.2.7 Termination with the Serving BS ................................. 117 6.3.2.8 Drops during Handover ............................................... 117 6.3.2.9 Network Entry/Reentry ............................................... 118
6.3.3 Macro Diversity Handover and Fast BS Switching ................. 118 6.3.3.1 Macro Diversity Handover .......................................... 119 6.3.3.2 Fast BS Switching .......................................................... 120
6.4 Paging and Location Update .................................................................. 121 6.4.1 Basic Paging Operation ............................................................... 122 6.4.2 Location Update ........................................................................... 124 6.4.3 Network Reentry from Idle Mode ............................................. 125
6.5 Summary .................................................................................................... 126 References ........................................................................................................... 127
and
The IEEE 802.16e system called Mobile WiMAX [1] has been standardized to add user mobility to the original IEEE 802.16 system (WiMAX) [2]. Since mobility causes a number of problems and requirements in wireless systems, to support user mobility, a mobile station (MS) and a base station (BS) in the mobile WiMAX system need to introduce several mobility-supporting functions to the existing WiMAX system [3].
