With reference to communication technologies, what is/are the difference/differences between LTE (Long-Term Evolution) and VOLTE (Voice over Long-Term Evolution) ? I. LTE is commonly marketed as 3G and VOLTE is commonly marketed as advanced 3G. II. LTE is data-only technology and VOLTE is voice-only technology. Select the correct answer using the codes given below:

The correct answer is D (Neither 1 nor 2), and both statements are wrong.

• Statement I is false. LTE is marketed as 4G, not 3G. It is 3GPP's fourth-generation standard and LTE-Advanced was accepted as IMT-Advanced. VoLTE is not 'advanced 3G' either. It is a voice service that runs over the same 4G LTE network.
• Statement II is false. LTE is a packet-based, all-IP access technology that carries both data and voice. VoLTE is not voice-only. It sends voice as IP packets over the LTE data pipe, using the IP Multimedia Subsystem (IMS) for call control. Before VoLTE, phones fell back to 2G/3G circuit-switched networks for calls (CSFB).

Core concept: LTE is the radio and core network. VoLTE is one application running on it. For Mains, this links to digital connectivity, spectrum policy and the move from circuit-switched to all-IP telecom networks under Digital India.

Trap: Aspirants either assume VoLTE is a separate generation, or read 'voice over LTE' as 'voice-only', which ignores that VoLTE still runs on a data network.