UAI – UE Assistance Information:
The purpose of this procedure is to inform to the network about specific needs that network should be aware of it and it should take action accordingly.
Few examples where this UAI information is used.
– its overheating assistance information; or
– its preference on DRX parameters for power saving; or
– its preference on the maximum aggregated bandwidth for power saving; or
– its preference on the maximum number of secondary component carriers for power saving; or
…
…
…
– its preference on the maximum number of MIMO layers for power saving; or
– its preference on the minimum scheduling offset for cross-slot scheduling for power saving;
Snippet for UAI with MIMO example:
NR5G RRC OTA Packet — UL_DCCH / ueAssistanceInformation Subscription ID = 1
message c1 : ueAssistanceInformation :
{
criticalExtensions ueAssistanceInformation :
{
nonCriticalExtension
{
nonCriticalExtension
{
maxMIMO-LayerPreference-r16
{
reducedMaxMIMO-LayersFR1-r16
{
reducedMIMO-LayersFR1-DL-r16 4,
reducedMIMO-LayersFR1-UL-r16 1
}
Here UE sends it requires fewer MIMO layers in uplink and downlink direction. so network in response sends RRC reconfiguration with adjusted configuration back to UE.
Reference: 38.331
