While Ericsson has been the equipment vendor leading the dynamic spectrum sharing (DSS) charge, it appears rival Nokia intends to offer its own version of the technology sometime next year.
“Nokia will introduce DSS as a software upgrade in line with commercial 5G FDD mass market device availability in 2020,” wrote Harri Holma, a Fellow with Nokia Bell Labs, in a Nokia blog post Monday.
Dynamic spectrum sharing enables mobile operators to utilize the same spectrum for both LTE and 5G New Radio (NR) technologies, meaning carriers can use existing LTE spectrum without having to dedicate scarce resources specifically for 5G.
“DSS between 4G and 5G will become an important technology with the introduction of 5G to the Frequency Division Duplex (FDD) bands,” wrote Holma.“The practical benefits of using DSS varies between operators due to their differing radio spectrum assets and their strategies for 5G services.”
Major carriers in the U.S., including Verizon and AT&T, have cited DSS as an important technology for extending 5G services.
“For example, used in conjunction with higher frequency bands (3.5 GHz), 5G FDD with DSS can boost the end user experience with an additional low-band carrier,” Holma continued. “Similarly, outside of the 3.5 GHz band, DSS provides a flexible way to extend 5G services using an operator’s legacy frequency bands.”
Initial 5G launches in the U.S. used millimeter wave frequency bands, which had never been used for 4G LTE, and didn’t need to share or take spectrum resources from legacy users. As carriers look to deploy broader 5G coverage though, they’re currently tapping lower spectrum bands, like T-Mobile’s 600 MHz and AT&T’s 850 MHz 5G rollouts.
Verizon has said it expects DSS technology to come into play in 2020. During an interview at MWC LA earlier this year, Heidi Hemmer, Verizon’s VP of Technology, said that while DSS will help improve all of the carrier’s network it will be particularly important in locations with large capacity needs, like entertainment venues or stadiums.
Some say the real advantages from DSS will happen when operators move to a 5G standalone (SA) core, when the technology can help to make features like network slicing possible. Nokia also pointed to benefits of DSS for 5G SA networks.
“DSS for 4G/5G should be used as part of a strategy that takes existing LTE and customer experience metrics into account and balances it with the knowledge that 5G customer expectation may go beyond the capabilities offered by this technology alone,” wrote Holma. “DSS will generate real performance gains with 5G standalone networks which are expected from 2021 delivering latency benefits in dense urban environments.”
Still, at this point Ericsson is currently the only vendor with a commercial 5G DSS product. Swiss operator Swisscomm, which introduced 5G in the first half of the year using 3.6 GHz spectrum, was the first operator to deploy Ericsson Spectrum Sharing (ESS) software.
In December Swisscomm teamed with Telstra in Australia, and together successfully demonstrated a transglobal 5G data call using Ericsson’s DSS technology that was deployed in both operators' commercial 5G networks.
The call was made over a 3GPP Frequency Division Duplex (FDD) band, with pre-commercial 5G smartphones provided by Chinese manufacturer OPPO and powered by Qualcomm’s Snapdragon X55 5G modem.