The UE Configuration Update Command is responsible for communicating the modification in the SMS state to the UE. The SMS state, such as allowed and not allowed is modified when the AMF CLI is modified or the AMF receives the subscription change notification through the UDM data change notification.

When the AMF detects changes in the SMS state for a UE, and the UE requested in the previously sent Registration Request for the SMS, the AMF notifies the new SMS state through the UE Configuration Update Command.

If the UE had requested the SMS based on CLI configuration or SMS subscription, the AMF marks the SMS as allowed or not allowed and informs the UE through the Registration Accept message. Later, when the SMS state changes at AMF; for example, the UDM subscriptions change the SMS state from allowed to not allowed. In that case, the UE Configuration Update Command notifies the UE with the SMS IE indication as not allowed.

For the UDM notifications, when the UE is in the CONNECTED state, the UE Configuration Update Command is triggered instantly. However, paging is triggered based on the AMF configuration if the UE is in the IDLE state.

Whenever the SMS state at AMF changes from allowed to not allowed, and if the SMS was previously activated, the AMF sends the Deactivation Request to SMSF.

The AMF starts a paging procedure when the SMSF sends the UE Reachability event for the MT SMS, and the UE is in the IDLE state. The AMF determines the paging profile specific to the SMS based on the configured trigger type. AMF uses the default paging profile when the paging profile is not configured.

When AMF receives the UDM notification containing the new data, and the UE is in the IDLE state, the AMF pages the UE to send the UE configuration update.

This feature complies with the following standards specifications:

• 3GPP TS 23.501 "System architecture for the 5G System (5GS)"

• 3GPP TS 23. 502 "Procedures for the 5G System (5GS)"

• 3GPP TS 24.501 "Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3"

• 3GPP TS 29.503 "5G System; Unified Data Management Services; Stage 3"

• 3GPP TS 29.518 "5G System; Access and Mobility Management Services; Stage 3"

• 3GPP TS 29.540 "5G System; SMS Services; Stage 3"

This feature has the following limitations in this release:

When the SMS over NAS CLI is enabled, the AMF always fetches the SMS subscriptions data from UDM along with AM and SMF selection data. If the feature CLI is not enabled during initial registration, the SMS subscription data is not fetched for the UE. Later, when the UE requests for the SMS support in the subsequent Periodic or Mobility Registration message, AMF does not have the SMS subscription data, and the SMS is not activated.

To enable the transfer of SMS over NAS, use the following configuration:

config 
  amf-global 
    call-control-policy policy_name 
      policy sms-over-nas { true | false } 
      end 

NOTES:

• call-control-policy policy_name —Specify the Call Control Policy name.

• policy sms-over-nas { true | false } —Configure the capability that is responsible to send the SMS over the NAS protocol.

To configure the NRF discovery, use the following configuration:

config 
   amf-global 
      operator-policy policy_name 
         ccp-name ccp_name 
         network-element-profile-list [ smsf ] 
         end 
   profile 
      network-element [ smsf ]  
         nf-client-profile nf_profile_name 
         failure-handling-profile failure_handling_profile_name 
         query-params [ target-plmn | instance-id ] 
         end 
      nf-client nf-type [ smsf ] 
         smsf-profile smsf_profile_name 
            locality locality 
            priority profile_priority 
            service name type [ nsmsf-sms ] 
               endpoint-profile endpoint_profile_name 
                  capacity profile_capacity 
                  priority endpoint_priority 
                  uri-scheme [ http ] 
                  version 
                     uri-version version 
                  endpoint-name endpoint_name 
                     priority endpoint_priority 
                     primary ip-address primary_ip_address 
                     primary ip-address port primary_port_numer 
                     secondary ip-address secondary_ip_address 
                     secondary ip-address port secondary_port_numer 
                     end 
      nf-pair nf-type [ smsf ] 
         nrf-discovery-group 
            locality   
               client client_locality 
               preferred-server server_name 
               geo-server geo_server_name 
               end 

NOTES:

• operator-policy policy_name —Specify the operator policy name.

• ccp-name ccp_name —Specify and configure the Call Control Policy name.

• capacity profile_capacity —Specify the endpoint profile capacity.

• nrf-discovery-group —Specify the NRF discovery group name.

• priority endpoint_priority —Specify the node priority for endpoint.

• client client_locality —Specify the client locality information.

• preferred-server server_name —Specify the Geo service locality information.

• geo-server geo_server_name —Specify the preferred server locality information.

To configure the failure handling profile, use the following configuration:

config 
   profile 
      nf-client-failure nf-type [ smsf ] 
         profile failure-handling profile_name 
            service 
              name type [ nsmsf-sms ]  
              responsetimeout timeout_interval 
              message type   
                 SmsfActivationReq { status-code [ httpv2 ] | action [ retry-and-ignore ] | retry retry_count }  
                 SmsfDeactivationReq { status-code [ httpv2 ] | action [ retry-and-ignore ] | retransmit  retransmit_count | retransmit-interval retransmit_interval } 
                 SmsfSendSms { status-code [ httpv2 ] | action [ retry-and-ignore ] | retransmit  retransmit_count | retransmit-interval retransmit_interval }  
                 end 

NOTES:

• failure-handling-profile failure_handling_profile_name —Specify the failure handling profile.

• responsetimeout timeout_interval —Specify the timeout interval in milliseconds. The default value is 2000.

• range range —Specify the range value. Must be an integer in the range of 0–599.

• retransmit retransmit_count —Specify the retransmit interval in milliseconds.

To configure the paging profile, use the following configuration:

config 
  amf-global 
   paging-map paging_map_name 
    precedence paging_precedence 
    paging-profile-name paging_profile_name 
    trigger-type [ sms ] 
    end 

NOTES:

• paging-map paging_map_name —Specify the paging map name. Must be string in the range of 1–64.

• precedence paging_precedence —Specify the precedence level. Must be an integer in the range of 1–255 with 1 indicating the highest and 255 the lowest.

• paging-profile-name paging_profile_name —Specify the paging profile name. Must be a character string in the range of 1–64.

• trigger-type [ sms ] —Specify the type of paging trigger.

To configure the paging feature, use the following configuration:

config 
   amf-global 
      call-control-policy ccp_name 
       policy idle-mode udm-notification initiate-paging [ SMS ]  
       end 

NOTES:

• policy idle-mode —Configure the UE configuration for the idle mode paging parameters.

• udm-notification initiate-paging [ SMS ] —Configure the paging for the UDM notification.

• By default, the paging feature is disable for the UDM notifications.

To configure this feature, use the following configuration:

config 
  tai-group name { name tai_group_name | range range } 
     timezone { + | - } hours value [ minutes { 0 | 15 | 30 | 45 } | daylight-savings-time-increment { 0 | 1 | 2 } ] 
   tais { name tai_list_name | range range | preference preference } 
     timezone { + | - } hours value [ minutes { 0 | 15 | 30 | 45 } | daylight-savings-time-increment { 0 | 1 | 2 } ] 
     end 

NOTES:

• To modify or update the time zone entry, use the following configuration:

  1. Configure no time zone using the no timezone command.

     For example:

     amf(config-tai-group-xxx)# no timezone 

  2. Configure the new time zone values.

• The AMF uses the configured time zone in the messages that are sent to the SMSF as part of ueTimeZone IE. When the time zone is configured at both tai-group and tai-list levels, the preference is configured under the tai-list.

• preference preference —Specify the preference. The time zone configured within the TAI list gets the preference.

• timezone { + | - } hours value [ minutes { 0 | 15 | 30 | 45 } | daylight-savings-time-increment { 0 | 1 | 2 } ] —Specify the time zone for the TAI list. The variables included the following:

  • { + | - } —Specify the offset direction from the Universal Time (UTC).

  • hours value —Specify the offset from UTC in hours. Accepted value must be an integer 0—14.

  • [ minutes { 0 | 15 | 30 | 45 } —(Optional) Specify the offset minutes that are added to the hours value.

  • daylight-savings-time-increment { 0 | 1 | 2 } —Specify the number of hours during which the time zone should be offset due to daylight savings time.

The following is an example configuration.

config
   amf-global
      operator-policy local      
      ccp-name local
      network-element-profile-list smsf smsf1
      end
   profile 
      network-element [ smsf ] 
         nf-client-profile SMSF1         
         failure-handling-profile FH1
         query-params [ target-plmn instance-id ]       
         end
      nf-client nf-type smsf
         smsf-profile SMSF1
            locality LOC1
            priority 56
            service name type nsmsf-sms
               endpoint-profile EP1
                  capacity   30                  
                  priority   30                  
                  uri-scheme http                  
                  version
                     uri-version v2
                     end
                  endpoint-name EP1
                     priority 30                    
                     primary ip-address ipv4 209.165.201.1
                     primary ip-address port 5182
                     seconday ip-address ipv4 209.165.201.2
                     seconday ip-address port 5084
                     end
      nf-pair nf-type SMSF
         nrf-discovery-group udmdiscovery
            locality client  LOC1
            locality preferred-server LOC1            
            locality geo-server GEO
            end