T-Mobile US tapped Cisco to launch a cloud-native 5G core gateway that expands the flexibility of the carrier’s 5G standalone (SA) core to support all of its 5G and 4G LTE traffic. The moves taps into long-standing work between the two firms.

The T-Mobile US 5G SA core is based on Cisco’s cloud-native control plane that uses Kubernetes to orchestrate containers running on bare metal. The companies said this frees up more than 20% of the CPU cores.

It also uses Cisco’s 8000 Series routers, 5G and 4G LTE packet core gateways, its Unified Computing System (UCS) platform, and Cisco’s Nexus 9000 Series Switches that run the vendor’s Network Services Orchestrator for full-stack automation. T-Mobile US noted that automation simplifies “network functions across the cloud, edge, and data centers to significantly reduce operational lifecycle management.”

The distributed nature of the 5G SA core deployment also provides a reported 10% improvement in speed and latency, which is key for mobile edge computing use cases.

“It’s like turning two townhouses into a massive mansion by removing walls (or barriers) and then loading that mansion with the latest, groundbreaking technology,” the carrier creatively noted in its press release.

5G core faster, better

T-Mobile US noted the platform will also allow it to more quickly test and deploy new services at scale. It cited specific 5G and IoT services, including its rapidly expanding fixed-wireless access (FWA) Home Internet service, the always popular network slicing, and voice over 5G (VoNR).

The carrier recently launched its VoNR service in a handful of markets. It allows devices to remain connected to the carrier’s 5G network for both voice and data sessions.

Neville Ray, president of technology for T-Mobile US, recently touted the carrier’s ongoing 5G SA expansion is allowing the carrier to more efficiently carry network traffic.

“We continue to test, we continue to optimize,” Ray said during the carrier’s most recent earnings call. “Why is that important? It’s important because we want to have all of our traffic, all of that customer experience on a 5G lane. Today, we have to drop our customers down off of that 5G lane onto LTE. And we’ve talked before about how we see our business as an all 5G network and having VoNR and that voice service is critical to executing on that strategy and making sure we have a full 5G network with full standalone capability.

"So we’re making progress, still got work to do. I’m not going to say it’s where we want it to be yet. But I’m confident over the next couple of quarters we will materially expand that footprint.”

T-Mobile US last month mixed in its deep 2.5 GHz spectrum assets to better support its 5G SA network. This allows the carrier to support more traffic on that network.

“The more that we can have this traffic living on a pure 5G lane with all of the spectral efficiency and capability that we can bring, the more that we can continue to grow and drive the experience to be much improved, be that from a capacity, speed perspective, 5G SA and mid-band is going to have material differences in terms of latency,” Ray explained during a recent investor conference.

Cisco’s 5G work continues

Cisco was part of T-Mobile US’ initial 5G SA core launch in 2020. This included the user plane, session management, and policy control functions. Those network functions run on Cisco servers, switching, and its virtualization orchestration stack.

This 5G work built on Cisco providing its packet gateway for T-Mobile’s 4G LTE mobile core, later adding its evolved packet core (EPC), and eventually virtualized the operator’s entire packet core in 2017. T-Mobile was also the first major operator to introduce Cisco’s 4G control and user plane separation (CUPS) in the EPC at production scale in 2018.

Cisco has also been core to 5G SA work by operators like Dish Network and Rakuten Mobile.