Mobile Assisted Handover (MAHO) in Mobile Communication

Introduction

Mobile Assisted Handover (MAHO) is a vital process in mobile communication systems that ensures seamless connectivity as a user moves between cells. In MAHO, mobile devices actively measure signal strengths and quality from nearby base stations and assist the network in deciding the optimal moment and target cell for handover. This guide explores the concept of MAHO, its role in mobile communication, and how it enhances network performance and user experience in cellular systems like GSM, 4G, and 5G. There are various types of Handoff viz. mobile initiated and base station initiated. We will understand Mobile initiated or mobile assisted handoff.

The figure depicts mobile assisted handoff. This is used in TDMA based frame structure typically used in GSM system.

As shown, the mobile is currently using TS0 and TS4 time slots for conversations with BTS-A. In order to perform handover, the mobile continuously performs RSSI measurements.

RSSI stands for Received Signal Strength Indication.

From the neighbour cell measurements, the mobile decides on which cell or BTS to handoff to. It does this based on higher signal strength among the ones collected.

Normally, the mobile uses either dedicated idle time slots in the TDMA frame or any unused time slots for the RSSI measurements. As shown, the Mobile is connected with BTS-A, i.e., the serving base station, while BTS-B and BTS-C are the target BTSs.

From BTS-B and BTS-C, whichever has a higher RSSI at the mobile station, the mobile will use that BTS for handover.

Conclusion

MAHO plays a vital role in modern mobile communication systems by ensuring efficient handover processes, maintaining call continuity, and enhancing user experience. By leveraging mobile devices to assist in signal measurement and decision-making, networks can optimize resource allocation and improve overall reliability. As mobile technologies continue to evolve, MAHO remains a cornerstone of seamless connectivity and network efficiency.