Supplemental Downlink

A radio communication strategy primarily used in 4G LTE and 5G NR systems where additional spectrum is allocated exclusively for downlink (base station to user equipment) communication. This method is particularly useful in situations where there is asymmetrical traffic demand, typically with a higher demand for downlink data. SDL bands are used in transcievers which use Carrier Aggregation, where the SDL band is added as a component carrier to increase downlink data speeds.