AT&T scales cloud RAN as open RAN swap passes 50%
Interview: AT&T completed a controlled introduction phase of its cloud RAN deployment, with roughly 25 sites running live traffic on Intel’s Sapphire Rapids processors as it plans to aggressively scale deployment when Intel’s next-generation Granite platform arrives over the coming months.
The Sapphire deployment is currently handling the TDD layers of the network, which represent the largest share of traffic, but not yet the full stack.
Rob Soni (pictured), VP of the operator’s RAN architecture, told Mobile World Live (MWL) Granite, which is already in AT&T’s labs, will enable a full stack covering FDD, TDD, NR and LTE from a single server design.
“This is all coming in phased pieces through the fall and early next year,” he said. “We plan to scale more aggressively on Granite than we did on Sapphire.”
He said AT&T expects to move from a few hundred Sapphire sites to thousands on Granite through 2026 and into 2028.
Performance on the Sapphire sites is matching traditional RAN on call drop rates and throughput, Soni said, and the team is beginning to utilise the platform’s promise of faster feature delivery.
The leading example is AI-driven link adaptation, developed with Ericsson, which replaces rules-based scheduling algorithms with a deep neural network.
Trials are showing roughly 10% gains in spectrum efficiency and 15% improvements in individual user throughput, with further benefits expected as AT&T tunes the global Ericsson model to its own network morphology.
“We’ve done a lot of trailing with the kind of global model of Ericsson,” Soni explained. “We’re now in the process of tuning the model to the AT&T morphology, the AT&T usage. That will change the nature, and we expect there to be more gain.”
Halfway point
In cellular networks, Soni stated a base station must determine on every transmission frame which users to serve, what modulation and coding scheme to use and how to balance competing demands across the spectrum.
It is a computationally intense optimisation problem, and the traditional approach has been to encode engineering judgment into static rule sets. The AI model Ericsson developed learns from network behaviour and adapts more fluidly to changing conditions.
Link adaptation is a critical algorithm for determining the overall multiple user performance in a cellular network,” he stated.
Rival T-Mobile US stated in May 2026 it is also trialling Ericsson’s AI-native scheduler with link adaptation on live 5G-Advanced traffic, but Soni noted AT&T has been trialling it since December 2025.
Soni told MWL AT&T is just past the halfway point for switching out Nokia’s RAN gear for Ericsson’s as part of a five year plan to transition 70% of its network traffic to run on open platforms by end of year.
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