AT&T claims it made another feat in its long and winding road to bring open radio access network (RAN) architecture to its 5G network with an assist from Intel.

The operator’s developing “Advanced DU pooling” with the chipmaker to bring elasticity to the distributed unit (DU) layer in the RAN, according to Gordon Mansfield, AT&T’s VP of mobility access and architecture.

The technology, which AT&T intends to make available to other 5G operators, provides the greatest value in centralized RAN deployments where basebands from “many sites are pooled together into a cloud of general purpose processors in far edge data centers or central offices,” Mansfield explained in a blog post. 

Moreover, the advanced form of DU pooling allows a single 5G radio to distribute baseband processing for each device in the cell across multiple servers, he added. 

“It gives unprecedented elasticity and flexibility to the network to distribute and redistribute traffic instantly,” Mansfield wrote. This also creates greater resiliency when a server gets overloaded or fails, and allows operators to consolidate user sessions into fewer servers during periods of light traffic, effectively putting unused servers to sleep and lessening their drain on energy, he added.

The technology uses Intel’s FlexRAN software stack running on Intel 3rd-generation Xeon Scalable processors. 

The effort brings AT&T closer to realizing its open RAN vision and will help it meet its commitment to become a carbon-neutral network by 2035, according to Mansfield. 

AT&T’s focus on RAN elasticity follows the operator’s six-year journey to virtualize 75% of its network functions, an effort that hit multiple snags along the way. By early 2021, multiple analysts questioned the significance of AT&T’s stature and success in network virtualization. 

The operator soon after effectively relinquished its role as a trailblazer on network virtualization, LightCounting consultant Roy Rubenstein said at the time.

AT&T has also been busy shedding and selling its Network Cloud technology to Microsoft as it shifted plans to move its 5G network core, workloads, and services to Microsoft’s Azure for Operators platform. The operator has yet to deploy a 5G standalone core, but said that will be the first order of business as it plans to move its existing network cloud to Azure by mid-2024.

Amid all of those changes, Mansfield’s update indicates AT&T hasn’t lost sight of the RAN. “Achieving elasticity in the RAN brings a completely different set of challenges to resolve. The RAN base station DUs are one of the most distributed, resource intensive, and complicated parts of a wireless network,” he wrote.

The disaggregation of RAN hardware from software and introducing common-off-the-shelf servers in place of proprietary basebands aims to change that. And AT&T’s Advanced DU pooling technology is designed to put that into production.

“The open standards for communications between radios and DUs that were published by the O-RAN Alliance enabled its development,” Mansfield wrote. 

“As we look ahead, AT&T is working with our RAN suppliers to incorporate DU pooling technology into commercial RAN software products that can be deployed” on AT&T’s network, he added.