With reference to communication technologies, what is/are the difference/differences between LTE (Long-Term Evolution) and VoLTE (Voice over Long-Term Evolution)?
- 1.LTE is commonly marketed as 3G and VoLTE is commonly marketed as advanced 3G.
- 2.LTE is data-only technology and VoLTE is voice-only technology.
Select the correct answer using the code given below.
Answer & explanation
Answer: (d) Neither 1 nor 2
Neither statement is correct. LTE is a 4G mobile network standard, not 3G, and VoLTE is not 'advanced 3G': it is simply the way voice calls are carried as data over an LTE network. LTE is therefore not 'data-only', and VoLTE is not a separate 'voice-only' technology.
- ✗ 1. LTE is marketed as 4G. TRAI's regulations treat VoLTE as voice over a 4G network (they cite ITU-T G.1028, end-to-end quality of service for voice over 4G mobile network). Nothing about either is '3G' or 'advanced 3G'.
- ✗ 2. An LTE network can carry voice as well as data. When it does, that voice service is VoLTE; when it does not, calls fall back to older circuit-switched networks (CSFB), as TRAI's explanatory memorandum notes. VoLTE runs on LTE, so the two are not data-only versus voice-only.
Remember · LTE is the 4G data network; VoLTE is voice calls carried over that LTE network, so a phone without VoLTE falls back to 2G or 3G for calls.
Sources
- TRAI: Standards of Quality of Service of Basic Telephone Service (Wireline) and Cellular Mobile Telephone Service (Sixth Amendment) Regulations, 2018, explanatory memorandum ↗ “VoLTE was also included in the revised QoS regulations and Explanatory Memorandum (EM) to fifth amendment referred to ITU-T Recommendation G.1028 which defines end-to-end quality of service for voice over 4G mobile network … if LTE network is not supporting voice i.e. VoLTE then user may be required to be pushed to other radio access technologies”
Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·