Voice over Wi-Fi (VoWiFi) is a term typically employed to describe the delivery of commercial telephony services using Voice over IP (VoIP) technologies from mobile devices connected across Wi-Fi.
This is typically counter to alternatives, predominantly Voice over LTE (VoLTE), in which a mobile network operator’s (MNO’s) licensed spectrum (i.e. 4G LTE) is used to carry packetized voice.
Broadly speaking, VoWiFi terminology is assigned to all core IMS services accessed from unlicensed spectrum and across untrusted access infrastructures, such as public Wi-Fi access points.
VoWiFi allows operators to offer a “Universal Wireless Service” anywhere around the world where users have access to Wi-Fi
• Wi-Fi APs + Hotspot 2.0 = in “neutral host” – allows operators to provide access to mobile core from anywhere in the world - MulteFire and Neutral Host are trying to emulate
• It literally turns APs into potential cellular towers and extends operators’ networks instantly without operators themselves deploying and operating them. Hundreds of millions of Wi-Fi APs around the world.
• Wi-Fi Calling is now a mainstream all around the world.
VoWiFi has moved from novelty to necessity and will be a key component of 5G for delivering converged services over any access networks.
Challenges:
Number of gap items and issues that need to be addressed to further help and promote the deployment and usage of Wi-Fi Calling including:
• Current deployments are trying to do their best with what is available today
– Lack of end-to-end standard based system specification and solutions for addressing issues: Emergency Call – Network Access without credentials, location, emergency number, routing, and priority of traffic
– Regulatory issues – Roaming, access, legal intercept
– QoE/QoS – End-to-end QoE and QoS, handling of QoS packet
– Seamless handover between 2/3G calls and VoWiFi
– Interruptions in multi AP environment with network detection, selection, authentication and latencies
– Enterprise blockage of IPSec tunnels to external peers
