5G Uplink Booster

Supplementary Downlink ( SDL ) and Supplementary Uplink ( SUL ) are modes that allow only downlink or uplink in those bands . SDL and SUL are meant to provide additional capacity. In practice, industry looks at 5G spectrum in terms of low-band (600-700 kHz), mid-band (3-5 GHz) and high-band (26-100 GHz).

Supplemental Downlink (SDL) has been enabled inThird Generation partnership Project (3GPP) Release 9 as part of the evolution of High Speed Downlink Packet Access (HSDPA) . While the serving carrier (cell) for an HSDPA UE is part of paired spectrum, the SDL carrier is part of unpaired spectrum in a different band.

In case of Supplementary Uplink, the UE is configured with 2 UL carriers for one DL carrier of the same cell , and uplink transmissions on those two UL carriers are controlled by the network to avoid overlapping PUSCH/PUCCH transmissions in time.28 Nis 2020

Supplementary uplink (SUL) is introduced in 3GPP Rel-15 to extend the uplink coverage by providing a supplementary uplink (usually in sub-3 GHz band) . With SUL, a DL frequency band (NR frequency band) and two uplink frequency bands (one NR frequency band and one SUL frequency band) are configured in the same cell.