AT&T to deploy network tech to aid 5G battery life

5G devices have long suffered from relatively poor battery life compared to 4G and 3G gadgets.

The situation was important enough for iPhone maker Apple to install a setting within its iOS operating system that allows users to funnel their traffic off 5G to preserve their phone's battery life.

More recently, network-monitoring company Ookla released new data showing the effects of 5G on phones' batteries. "5G use drains your smartphone battery faster than 4G-LTE," the firm wrote. "Ookla Speedtest Intelligence data shows that smartphone users accessing 5G networks experience higher battery drain than those using 4G-LTE, of between 6 percent and 11 percent, depending on the System on Chip (SoC) in their device."

The firm reported that Qualcomm's latest flagship SoC, the Snapdragon 8 Gen 2, managed to consume the least amount of power of the SoCs it tested. Ookla reported testing phones running chips from Qualcomm, MediaTek, Samsung and Google.

Click here for a larger version of this image.
(Source: Ookla)

Networks to the rescue

Of course, phone makers primarily control the performance of their gadget's batteries. But Sebastian Barros, a top executive at wireless equipment maker Ericsson, argued there are technologies within wireless networks themselves that can help improve 5G battery life.

"Your battery drains faster on 5G, but the industry is working to fix this," he wrote in a recent LinkedIn post. He specifically listed several new networking technologies – including RRC_INACTIVE State, DRX + WUS and Maximum MIMO Layers Reduction – as capable of reducing the strain 5G can put on a phone's battery.

Light Reading reached out to officials from AT&T, T-Mobile and Verizon – the top 5G network operators in the US – to see whether they were working on the issue.

"From longer term industry standardization advancements to ongoing network optimizations, AT&T is working with our ecosystem partners to provide the best user experience for our customers," Jason Sikes, a top AT&T networking executive, wrote in response to questions from Light Reading.

Sikes said that "in the coming months," AT&T would introduce two technologies designed to improve the battery life of its customers' phones. Sikes said that Bandwidth Part Switching is a new 3GPP feature that can enable AT&T's network to modulate its connections to provide speed when necessary, and back off and preserve battery life when possible. Another technology – User Equipment Assistance Information (UAI) – promises to allow "the device to inform the network of its preferred connection parameters (e.g., MIMO layers, number of component carriers, RRC state, etc.) depending on the activities it is performing, thermal and device current consumption," according to Sikes.

He said other technologies under review at AT&T include RRC_Inactive mode, Wake Up Signal (WUS), Thermal management and 5G Reduced Capability (RedCap), which he said could help with customers' battery life.

Officials from T-Mobile and Verizon either did not respond to questions from Light Reading on the topic or did not offer any insights into their plans.

Heat and power

Finally, a new report from the analysts at Signals Research Group offers a look at the relationship between network speeds, battery life and device heat.

"Yes, 5G usage can kill the battery but it generally happens after consuming lots and lots of data. Once you equate data speeds, data usage and battery life, the real outcome is that faster data speeds almost always result in improved current efficiency, or the achieved data speed relative to the associated battery drain required to achieve that speed," the firm wrote in a new report.

Specifically, the analysts tested the speeds, battery life and thermal performance of several unnamed 5G phones connected to millimeter wave (mmWave) networks. Such networks are typically only available in downtown areas or inside airports and sports stadiums, but they can support blazing fast speeds. mmWave connections have long been shown to heat up phones.

"Although 5G mmWave phones tend to get hotter faster ... the subsequent higher data speeds more than offset the rate of increase in the temperature," the firm wrote of its testing. It added that some phones got hotter than others, which it attributed potentially to the location of the 5G modem relative to the temperature sensors near the battery.

SRG summarized: "The point ... is that the more rapid increase in temperature also corresponded with much faster data speeds, meaning that when downloading a fixed amount of data, the absolute increase in temperature was almost always lower when the smartphone was downloading at a faster speed. This statement is true even though the smartphones also experienced a more rapid increase in temperature when downloading at faster speeds."

Related posts:

— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano