The Evolving Voice Services

Resumen

Voice is the most pervasive telecommunication service, particularly mobile voice, with 4.7 billion unique mobile subscribers as of April 2016. Legacy circuit switched voice still accounts for the majority of world telecom customers, although voice‐over IP is finally starting to substitute it. Voice‐over IP technology has been available for more than a decade, but deployment of All‐IP access networks has been the trigger for its adoption. Only in the enterprise segment, the legacy PBX systems have initiated the migration earlier. In fixed networks, initial FTTH deployments maintained simultaneous use of legacy copper for voice. In 4G mobile networks, the fallback to 2G/3G for voice has been a temporary patch until the VoLTE deployment in the network and progressive availability of enabled devices. HD Voice is included in VoLTE, but is also available in 3G networks without VoIP. Voice‐over WiFi is emerging as a complement mainly for zones with poor cellular coverage.