Multi-radio spectrum sharing, commonly expanded as multi-RAT spectrum sharing, is a proposed way for different generations of radio access technology, especially 5G and 6G, to operate in the same frequency band. Instead of clearing all existing users from a carrier at once, an operator could allocate radio resources across generations as demand changes.
This matters because valuable lower- and mid-band spectrum is already busy with 5G and older services. Sharing may ease migration and help operators introduce 6G while continuing to support existing phones. Engineers are studying scheduling, signaling overhead, interference management and the performance trade-offs involved.
MRSS does not mean all 5G base stations become 6G-ready automatically. Hardware processing, radio capabilities, software, timing and commercial support may still require upgrades or replacements. As of late 2026, 3GPP evaluation of 5G–6G spectrum sharing is part of ongoing standards development, not a guarantee of uniform deployment.
Treat claims about reduced migration cost as conditional. Ask for measured capacity overhead, supported bands, compatible equipment and the operator's specific rollout design before assuming substantial reuse.