Build a BTS VoIP Kit for Android-based Communication Needs (Handset)

VoIP BTS is a device that functions as a telephone exchange for voice service services that can conduct long distance voice communication without depending on the provider. The purpose of this study is to make voice service services on the internet protocol using a network layer in Session initial protocol (SIP) signaling that is used as an Android smartphone as a client to register the service. The characteristics of this system are the type of contract, and audio codecs that are used are G.711 alaw / GSM codec, open source Asterisk software as a telephone exchange software, and Radio Wireless Local Area Network (WLAN) 802.11n which works at a frequency of 2.5GHz as topology network. The main focus of this research is that the IP telephone flow is not only for VoIP to VoIP services on VoIP BTS but is able to interconnect to GSM BTS for the recruitment of Indonesian GSM provider numbers. Quality of Service (QoS) produced on VoIP BTS is according to ITU-T G114 standard in service voice quality needs with Jitter VoIP to VoIP (5.70 ms) and VoIP to GSM (9.29 ms) values, delay VoIP to VoIP (32.4 ms) and SIP to GSM (39.28 ms), Troghput VoIP to VoIP (81.6 Kbps) and VoIP to GSM (86.4 Kbps), and packet loss VoIP to VoIP (0%) and VoIP to GSM (0%).