Optimum Will Start Using T-Mobile’s 5G Standalone Core to Upgrade Its Mobile Service

OPTIMUM MASTER AGENT

Dealer takeaway: Cable + mobile bundling is getting smarter. Optimum’s move signals that MVNOs can level up fast by tapping a carrier’s 5G SA core instead of building every capability in-house. Dealers should prepare for more “bundle math” questions, more connected-device sales (watches/tablets), and more roaming conversations—especially for customers who travel.

What Optimum announced

Optimum says it’s expanding its MVNO agreement with T-Mobile so Optimum Mobile customers can access T-Mobile’s 5G standalone (SA) core. Until now, Optimum’s wireless customers have been running on Optimum’s own in-house-built mobile core.

Optimum says adding access to T-Mobile’s 5G SA core will give customers:

• More device options (smartphones, wearables, tablets and other connected devices)

• Better international roaming options and partner coverage

• New launches and improved offerings starting early next year (after platform upgrades)

Quick timeline: Altice Mobile → Optimum Mobile

Optimum entered wireless in 2019, originally launching as Altice Mobile using Sprint’s network. After T-Mobile acquired Sprint, the underlying network shifted to T-Mobile in 2020. In 2021 the service was renamed Optimum Mobile, and in 2022 Optimum extended its multi-year MVNO agreement with T-Mobile.

Why this matters: two cores, more capabilities

According to Optimum Chief Product and Technology Officer Luciano Ramos, Optimum’s wireless service has run on its own core network. With the expanded deal, Optimum will have access to two mobile cores:

• Optimum’s in-house mobile core

• T-Mobile’s 5G SA core

Ramos said the goal is to access services T-Mobile has already developed on its standalone core rather than rebuilding those capabilities internally.

Optimum expects many customers will ultimately land on the T-Mobile standalone core because it supports a wider portfolio of devices. Optimum says it will assign accounts to the best core based on the products and services a customer chooses.

Speed/coverage and roaming improvements

As Optimum migrates customers, it says it will gain access to different frequencies on the T-Mobile network that can improve speed and coverage.

The core choice also affects international roaming. Ramos said Optimum currently offers roaming through partners, but T-Mobile’s larger roaming footprint and partner depth can provide more options in-country—helping devices choose the best available roaming network.

Bundling is the real endgame

Optimum is primarily a broadband provider and uses mobile as a bundle add-on. Ramos said the expanded T-Mobile deal gives Optimum the opportunity to rethink packages and evolve its product set now that it has new capabilities.

When asked about other cable operators, Ramos said Comcast and Charter run on Verizon’s network and core, rather than building their own mobile cores.

Dealer playbook: how to profit from this shift

1) Sell the “connected device stack,” not just a phone line

• Wearables: add a watch line with setup + notifications + safety features

• Tablets/hotspots: bundle for travel, kids, and remote work

• Accessory attach: chargers, cases, screen protection, Bluetooth audio

2) Turn roaming into a retention conversation

• Ask: “Any travel coming up in the next 90 days?”

• Pre-check: device compatibility + plan roaming rules + settings

• Offer a paid “travel readiness” setup service (SIM/eSIM, Wi‑Fi calling, data limits)

3) Bundle math: make it simple

• Show the customer a 3-line comparison: broadband-only vs. bundle vs. bundle + connected device

• Position the bundle as fewer bills + easier support + better value

Bottom line

Optimum’s move to add T-Mobile’s 5G SA core is a clear sign that MVNO competition is evolving beyond “cheap lines.” Expect better device support, stronger roaming, and new bundle offers starting early next year—plus more opportunities for dealers to win on setup, education, and multi-device attach.