Singtel posted Singapore's fastest median 5G call setup time of 1.07 seconds in controlled benchmarking carried out by Ookla during the second half of 2025, putting it well ahead of rival operators StarHub (1.82 seconds) and M1 (3.62 seconds).

The Ookla study measured Voice over New Radio (VoNR) performance across Singapore's three mobile network operators and exposed significant variance in how quickly voice calls connect on standalone 5G infrastructure. More than 90% of Singtel's tested calls connected within two seconds. By contrast, only 57% of StarHub's calls hit that mark, and M1's distribution was markedly wider despite a year-on-year improvement.

How does VoNR compare with VoLTE across operators?

Voice over New Radio is the 5G-native successor to VoLTE and the standard carriers are migrating toward as they retire legacy circuit-switched voice paths. Ookla's broader dataset, drawn from eight markets with sufficient samples for both technologies, recorded a median VoNR call setup time of 1.96 seconds against 1.87 seconds for VoLTE. Only six of the eight operators with usable data recorded faster call setup on VoNR than on VoLTE.

The narrow cross-market gap underlines how 5G voice has not yet matched the consistency operators built into their 4G networks over more than a decade of refinement. In Singapore, Singtel's VoNR result of 1.07 seconds beat its own VoLTE baseline of 1.22 seconds. StarHub's VoNR at 1.82 seconds was slower than its VoLTE performance. M1's VoNR nearly halved its VoLTE figure of 6.41 seconds, even though it remained the slowest of the three.

Why does Singtel lead?

Ookla links Singtel's consistency to network maturity, broader coverage and ongoing optimisation rather than to spectrum assets alone. The operator's tight spread between fastest and slowest test results signals a uniform customer experience across the test scenarios.

StarHub's slower outcomes were concentrated at the higher end of the testing range, a pattern that points to degradation under specific coverage or signalling conditions. M1's wider variance aligns with its position as a smaller operator still scaling VoNR traffic; roughly three-quarters of its tested calls already ran on the 5G voice standard, the highest VoNR share among the three.

What is holding back 5G voice consistency?

The Singapore findings illustrate a wider pattern: rolling out 5G coverage does not automatically deliver faster or more reliable voice. Several factors drive call setup variance in practice:

• 5G radio coverage gaps that force fallback signalling to 4G
• Signalling load on the 5G core as VoNR traffic scales
• Device interoperability issues that trigger fallback to VoLTE
• Operator-specific traffic management and prioritisation policies

Ookla said the differences could be linked to factors such as 5G network coverage, signalling and how traffic is managed across the network.

StarHub's numbers are the clearest example. Only 57% of its 5G voice calls connected within two seconds, compared with nearly 80% on VoLTE. The gap suggests StarHub's 4G voice network, refined through years of investment, still produces a more predictable experience than its newer 5G service in certain conditions.

What comes next for Singapore's operators?

Singapore's three mobile operators have largely completed their initial 5G coverage commitments. Competition is now shifting from headline peak speeds to service-quality metrics such as voice reliability, session continuity during handover and indoor performance.

Ookla's findings imply operators will need to refine VoNR signalling, expand coverage in weaker cells and continue coaxing older devices off legacy voice paths to close the consistency gap with 4G. As 5G device penetration rises, VoNR traffic will grow, and operators with less mature optimisation risk seeing call setup times drift higher.

M1's improvement from 6.41 to 3.62 seconds in a single technology generation shows the gains available. Matching Singtel's sub-1.5-second consistency will be the benchmark the others target through 2026 as 5G voice services continue to scale.