What is Dynamic Spectrum Sharing or DSS?

Dynamic Spectrum Sharing (DSS) is a technology that allows the deployment of both 4G LTE and 5G NR in the same frequency band and dynamically allocates spectrum resources between the two technologies based on user demand.

This can be easily understood with the help of an example. Suppose, without DSS, an operator that has 20 MHz of mid-band spectrum would have to split that spectrum in two. In other words, they would have to allocate 10 MHz of spectrum to 4G LTE and cram all their LTE users into that 10 MHz of spectrum. Then the remaining 10 MHz of AWS spectrum could be used for 5G, even though initially there will only be a minimal number of 5G users. 

With DSS, an operator doesn’t have to split that mid-band spectrum or have a dedicated spectrum for either 4G LTE or 5G. Instead, they can share that 20 MHz of spectrum between the two technologies.