LTE is a full packet switching (PS) technology. Unlike other mobile access technologies such as GSM, WCDMA and CDMA, which include support for traditional circuit-switched (CS) telephony services, LTE does not. The telephony service on LTE is a mobile broadband service on the PS domain. It depends on the LTE wireless and evolved packet core network (EPC) to meet the needs of the telephone service. VoLte is selected by the industry to provide carrier telephony services over new LTE access networks.
GSMA operators in early 2010 decided to lead the development of telecommunications for the voice and SMS on the field of LTE, the standard program.
This profile is the minimum required subset of features defined by 3GPP to help operators and vendors establish interoperable LTE voice and SMS services. GSMAIR.92 “IMSProfile for Voice and SMS” is a generic VoLTE (Voice over LTE) reference document; VoLTE also refers to the GSMA IR.94 “IMS Profile for Conversational Video Service”, which has developed unique capabilities to increase video media capabilities to VoLTE.
We consider VoLTE as the voice and video service over LTE, and do not need to be limited to the minimum capability set defined in IR.92 / 94. VoLTE In addition to providing high-definition voice and video capabilities, the same VoLTE is defined as a first-line telephone service, to meet the required business capabilities and performance.
RCS (Rich Communication Suite) defined by the GSMA provides converged communication services through mobile PS access and / or Wi-Fi access, ensuring interoperable services between carriers. Communication services include video and file sharing from a call, one-to-one and group chat, one-to-one and group-to-group file transfers to IP-based voice and video calls.
RCS enrichment of the telecommunications business is a supplementary telephone business, in this telephone service can be a traditional CS phone, it can be VoLTE.
RCS also provides telephony services over any IP connection (typically Wi-Fi), i.e. voice and video calls, when the first-line telephony services (CS and VoLTE) are not available, or when users do not want to use them. It is also possible that the CS is used to provide voice services and the user wishes to provide a video call through the PS.
RCSIP voice / video calls (without specific QoS guarantees) allow operators to compete with similar services offered by OTT communication service providers. When VoLTE includes video, VoLTE services provide QoS and meet regulatory requirements. However, in a VoLTE-capable terminal, the RCS can use the voice / video capability provided by VoLTE without necessarily using the capabilities provided by the CS. In addition, when the VoLTE terminal is attached to LTE and the VoLTE service is provided, the RCSIP voice / video call cannot be used.
RCS communication experience similar to OTT applications, is considered to be the key to retain customers. We see that RCS is a flexible evolution of the personal communication services and VoLTE interoperability of the basic platform. Ericsson’s evolution of communications solutions supports all core communications services and a variety of broadband access methods to ensure interoperability and business differences.
When RCS and VoLTE services coexist, operators need to provide end users with a unified, integrated communications experience. This indicates that the same IMS network framework, the same originating communication service address book, the same user identity (E.164, MSISDN) business contract information. Depending on the currently available access network and service requirements, such coexistence services provide the best possible user experience.
As a summary, there are market players who are leading and driving RCSIP voice / video calls and VoLTE coexist on the same network with the same terminal. The timetable for business promotion and business evolution makes it necessary to support different coexistence mechanisms. However, mobile operators have the flexibility to decide whether to support RCSIP voice / video calls by clarifying the points such as:
• Which services are to be provided (end-to-end VoIP, VoIP to legacy network CS, either or both).
• Which bearer can provide VoIP (some or all Wi-Fi, HSPA PS, 3G PS and LTE).
• Which users are allowed to use this VoIP service
At Damall, we work on target based on user’s unique experience to provide most advanced unified communication platform.