With the rise of 4G technologies and the deployment of several LTE networks, voice over LTE is becoming more and more a necessity. One of the major challenges standing in the way of MNO’s towards all-IP networks is to benefit from the cost-effectiveness  of the ecosystem while maintaining a superior level of quality for both, voice and SMS services over LTE. This requires a fully compliant ecosystem equipped with robust handset clients in order to provide transparent end-user experience in terms of voice, SMS, as well as other supplementary services over LTE. IMS, which has become the platform of choice for an increasing number of MNOs, is considered to be the corner stone for VoLTE services. IPneo has been among the very first companies to provide VoLTE clients thanks to its complete, standards compliant IMS stack that responds to the market call for reliable, interoperable, and portable VoLTE clients.

IPneo offers a distinctive VoLTE client that is fully compliant with the latest GSMA profile for Voice over LTE. IPneo’s VoLTE client, has been designed to provide both LTE OEM's and operators with a safe path towards reliable Voice over LTE services. The client is built upon a robust IMS stack that provides all necessary IMS core functionalities including registration, AKA authentication with IPSec support, session setup and resource reservations. AMR voice codecs (both WB and NB) are supported in bandwidth efficient mode with an optimized jitter buffer implementation according to MMTel recommendations. The media plane runs on top of an optimized RTP stack thus enabling voice communications with high quality. The client is built with VoIP and supplementary services enablers thus enabling easy integration with any VoIP application to run on top of IPneo’s VoLTE client. The client is quite modular and flexible, provided with a well-defined set of API's to allow full access to the core functionalities, and it is both hardware and OS independent. This gives both OEM's and operators the freedom of choice between different target platforms and shrinks their time to market.

Features:

• Full compliance with VoLTE profile (IR.92)
• SIP-based registration and call setup
• IMS AKA with IPSec support
• Supplementary services support (Call forwarding, Incoming/Outgoing Call Barring, ID presentation and restriction, etc…)
• Emergency services support
• SMS over IP
• QoS negotiation using SIP Preconditions
• Seamless support of dedicated signaling and media bearers
• AMR-NB and AMR-WB codecs in both octet and bandwidth efficient modes

VoLTE Client Architecture:

• VoIP
  • Exposes the interfaces needed for the application to initiate, receive , accept or reject voice calls
  • Interacts with the Supplementary services for call privacy, call waiting, call diversion, hold, resume, and ad-hoc conference calls

• SMS over IP
  • Exposes the interfaces needed for the application to send and receive messages over IP and display delivery notifications

• Supplementary Services
  • Interact with VoIP services module for handling supplementary services
  • Interacts with XCAP for configuring and retrieving Supplementary services configurations from Application server

• IMS stack
  • SIP Stack - Implements the complete SIP protocol
  • SDP Stack - Negotiates the supported codecs and updates the sessions accordingly
  • RTP Stack - Implements the complete RTP/RTCP protocols
  • Resource Reservation - Guarantees the required resources based on SIP preconditions and the underlying access layer
  • Sigcomp - Implements the Signalling compression for SIP messages

• Environment Layer
  • Link Abstraction - provides the IMS stack abstraction from the access network (EUTRAN, UTRAN, GERAN, WiFi, etc...)
  • Security Abstraction - provides the IMS stack abstraction from the platform dependent TLS and IPSec implementations
  • Audio/Video Abstraction - provides the IMS stack interface to platform dependent audio and video drivers