LTE uses an all IP data network, with voice calls reduced to a multim.pdf
- 1. LTE uses an all IP data network, with voice calls reduced to a multimedia application. Describe the benefits to the network operator of this approach, including the relationship between the core network and the radio access network, as well as other benefits from using a full IP network rather than the GPRS approach. Solution Voice calls over LTE is commonly known as VoLTE (Voice over LTE) which delivers voice service as data flows over LTE channels. VoLTE service contains an IP multimedia subsystem network, known as multimedia telephony service (MMTel). This is a global standard for real time communication using voice, video text and files. This serves to be the core network for VoLTE and eliminates the need for a legacy circuit switched network. The main advantages for a network operator in this case are: The radio access network is a part of the remote device (e.g. Mobile) that provides access to the operator’s core network. In case of VoLTE, it is termed as Evolved UMTS Terrestrial Radio Access Network (E-UTRAN). This radio access network is different and incompatible with any earlier technology like HSPA/HSUPA. It is more optimized for packet data and provides much higher data rates and lower latency. EUTRAN uses orthogonal frequency division multiple access (OFDM) for the downlink and single carrier frequency division multiple access (SC- FDMA) for the uplink. EUTRAN consists of eNodeB (enhanced Node B) which transmit and receive signals from the mobile devices. They interface with the core network using S1-AP protocol S1 mobile management entity (MME) interface for the control plane traffic. It uses the GTP-U protocol on the S1-U interface with the service gateway for user (data) plane traffic. Collectively the S1-MME and S1-U interfaces are known as the S1 interface, which represents the interface from the radio access network to the core network for VoLTE.