Feasibility of LTE-Based GEO Satellite Mobile Communication Systems to Support VoIP for Handheld Terminals

Abstract

To facilitate the integration of terrestrial and satellite mobile communication systems in the future, the new generation of satellite mobile communication system should be Long-term evolution (LTE)-based. In LTE, voice is carried by Internet protocol (IP) packets (voice over IP, VoIP). The feasibility of LTE-based Geosynchronous earth orbit (GEO) satellite mobile communication systems for VoIP is discussed. Detailed link budgets are created for typical handheld terminals. The effectiveness of Physical resource block (PRB) bundling and Transmission time interval (TTI) bundling for the capacity improvement of downlink and uplink are evaluated, and further uplink improvement for low level terminals by Narrowband resource block (NRB) scheme is also studied. The analysis results show that the downlink VoIP transmission is mainly power limited, and optimization of PRB or TTI bundling can maximize the capacity. For uplink, only highlevel terminals can support VoIP under the normal LTE frame structure, and TTI bundling and Resource block (RB) block techniques can help the low-level terminals support VoIP transmission.