AT&T is architecting tomorrow’s wireless network to connect people to greater possibility. As engineers, theydesign, build, test, refine and repeat to get more out of 5G's connection and developers can build and deploy the next generation of apps and services.

A key part of this evolution is the critical transition phase AT&T is entering in scaling from 5G Non-Standalone (NSA) to 5G Standalone (SA).

How does SA take 5G to the next level? Unlike 5G NSA that still relies on a 4G LTE core, 5G SA uses a dedicated 5G core that can unlock capabilities like faster upload speeds, ultra-low latency, ultra-high reliability and edge functions. This technology will be key to business opportunities like the next generation of connected cars.

AT&T has said that they plan to deploy SA 5G when the ecosystem is ready, and AT&T is charging forward to advance SA ecosystem readiness. Businesses and developers will be some of the first to take advantage of the new technologies 5G SA enables as we continue to move from research and development to their deployment.

Uplink: where challenge meets opportunity 

This new age of connectivity is not only about consuming more content but also generating more content than ever before. Demand for uplink capacity and speed continues to increase, about 30 percent a year in AT&T’s mobility network.

Whether you are uploading large files, on a video call with family, live streaming, cloud gaming or using extended reality applications, the network is facing surging upstream traffic demands it never has before. 

Just a few weeks ago, AT&T completed the first 5G SA Uplink 2-carrier aggregation data call in the U.S. CA means they are combining or “aggregating” different frequency bands to give you more bandwidth and capacity. For you, this means faster uplink transmission speeds. Think of this as adding more lanes in the network traffic highway.

No one in the U.S market has successfully aggregated two carriers in 5G SA uplink – until now.

The test was conducted in AT&T labs with Nokia’s 5G AirScale portfolio and MediaTek’s 5G M80 mobile test platform. AT&T aggregated their low-band n5 and our mid-band n77 spectrum. Compared to the low-band n5 alone, a 100 percent increase was seen in uplink throughput by aggregating the low-band n5 with 40 MHz of the mid-band n77. Taking it a step further, they achieved a 250 percent increase aggregating 100 MHz of n77,  achieving upload speeds of over 70 Mbps on n5 with 40 MHz of n77 and over 120 Mbps on n5 with 100 MHz of n77.

While carrier aggregation is like adding more traffic lanes in the highway, adding another vehicle to carry traffic is another way we are managing surging uplink demand. This is being done via a two-layer uplink MIMO on time-division duplex (TDD) in the mid-band n77. MIMO combines signals and data streams from multiple antennas (“vehicles”) to improve signal quality and data rates. This feature will not only improve uplink throughput but also enhance cell capacity and spectrum efficiency.

Network design and device readiness go hand in hand

Although AT&T continues to make progress in enhancing uplink coverage, they haven’t forgotten about the downlink. Enhanced downlink and uplink carrier aggregation capabilities work together to bring the 5G SA performance today’s technologies need.

Last fall, AT&T completed a 5G SA four component carrier downlink call by combining two frequency-division duplex (FDD) carriers and two TDD carriers.   These capabilities enable AT&T devices to aggregate our mid-band n77 in the C-Band and 3.45 GHz spectrum ranges. Compared with low-band and mmWave spectrum, mid-band n77 provides a good balance between coverage and speed. This follows the 5G SA three component carrier downlink feature that we introduced last year to 2022 AT&T Flagship devices which combines one FDD carrier and two TDD carriers.

In the coming months, AT&T will also enable 5G New Radio Dual Connectivity (NR-DC), aggregating the low and mid-band spectrum with the high-band mmWave spectrum on 5G SA.  AT&T labs have achieved 5G NR-DC downlink throughput speeds of up to 5.3Gbps and uplink throughput speeds of up to 670 Mbps. This technology will help provide high speed mobile broadband for both downlink and uplink in stadiums, airports and other high density venues.

The 5G SA ecosystem is rapidly evolving, with new technologies and capabilities being introduced to provide differentiated experiences. Here are some features that are on the horizon for 5G SA:   

• Specialized Network Services –network slicing, precision location, private routing, etc. – for tailored network solutions to meet specific user requirements
• Non-terrestrial network solutions to supplement coverage in remote locations 
• Reduced capability 5G (RedCap) for a new generation of 5G capable wearables, industrial IoT or wireless sensors and other small form factor consumer devices.

AT&T is dedicated to being the best connectivity provider. The 5G SA ecosystem is rapidly evolving, with new technologies and capabilities being introduced to set the foundation for next generation applications and services.