T-Mobile Skeptical About Dynamic Spectrum Sharing

T-Mobile sees limited potential for dynamic spectrum sharing (DSS) in carrier networks, Egil Gronstad, senior director-technology development and strategy, said Tuesday. During an Ookla webinar, Gronstad said T-Mobile views its early move to launch a 5G stand-alone (SA) network as critical. It examined DSS and found the efficiency is “pretty bad,” he said. DSS has been “hyped a lot … and we also had high hopes for it.” T-Mobile decided “very early on” that it wanted to make a “quick pivot to SA.” He added, “We drove the chipset and ecosystem very hard from the very beginning to support SA.” Almost all the devices on T-Mobile’s network are SA-capable. That has allowed the carrier to “quickly refarm spectrum from LTE to 5G." Gronstad thought T-Mobile’s major competitors would have done more to move to SA by now. T-Mobile has also worked hard on voice-over new radio (NR), which is voice on a 5G network. “Voice-over NR was a fairly large undertaking -- almost as large as voice-over LTE back in the day.” Vendors tell T-Mobile “just a handful” of operators are moving to voice-over NR globally “and we are five years into the 5G journey,” Gronstad said. “There is a lot more to be done still.” T-Mobile considers high-band spectrum for 5G a “failure.” The carrier didn’t fall “for this millimeter-wave trap,” which was “mostly set up by academia.” Verizon “took the bait and banked on millimeter-wave.” Gronstad also underscored the importance of handset makers enabling the use of new technology in their phones. The pro versions of Apple’s new iPhone 16 support power class 1.5 and uplink multiple-input and multiple-output, “which was music to my ears,” he said. “We have been working so hard to try to get the flagship handset vendors to support this.” Those additions will improve coverage capacity and throughput, he said.