VoIP over DVB-RCS Satellite Systems: A Novel Capacity Request Mechanism for Improved Voice Activity Detection

Satellites can complement terrestrial networks in Internet service provision by addressing the market which lies out of their reach. Despite of the global coverage, satellite networks entail high propagation delays and usually limited user bandwidth. VoIP is an example of an application which is subject to performance impairments due to these characteristics. VoIP trials over existing broadband satellite offers reveal that the application can be carried out with an acceptable quality. However results also reveal the need for further improvement of the bandwidth on demand scheme in order to reduce delay or improve bandwidth utilization. This paper presents a novel capacity request mechanism based on the accurate modeling of VoIP traffic as well as cross-layer design. Our analysis and simulation results show that our approach outperforms fixed capacity allocation mechanisms in terms of bandwidth efficiency or traditional bandwidth on demand schemes in terms of QoS.