NB-IoT and LTE-M RAT Type Support

Table 1. Feature History

Feature Name

Release Information

Description

RAT Type NB-IoT and LTE-M support

 2025.03.0

cnSGW-C supports "RAT Type NB-IoT and LTE-M" to enable accurate identification and differentiation of Narrowband IoT (NB-IoT) and LTE-M devices in Charging Data Records (CDRs) for precise billing.

Command introduced:

gtpp-attributes additional-rat-type [lte-m nb-iot] — Used to enable RAT Type NB-IoT and LTE-M.

Default Setting: Disabled – Configuration Required

RAT Type NB-IoT and LTE-M support refers to the ability of a network to recognize and differentiate between two specific types of Radio Access Technologies (RATs): Narrowband IoT (NB-IoT) and LTE-Machine Type Communications (LTE-M). These are specialized technologies designed for Internet of Things (IoT) devices, offering optimized connectivity for low-power, wide-area (LPWA) applications.

Why Differentiation in RAT Type is Important

Both technologies coexist on the 4G or 5G core network but serve different purposes and use cases. Differentiating these RAT Types in network elements like Serving Gateways (SGWs) helps operators:

  • Generate accurate Charging Data Records (CDRs) for billing.

  • Enable specific configurations for optimized performance.

  • Analyze metrics and monitor IoT device traffic based on their RAT Type.

Enable RAT Type NB-IoT and LTE-M for CDR

This task allows operators to configure RAT Type Information Elements (IE) for NB-IoT and LTE-M devices, ensuring precise billing, streamlined monitoring, and efficient network management.

Procedure

Step 1

Enter the SGW charging profile configuration mode.

profile sgw-charging-profile profile_name

Example:

[sgw] smf(config)# profile sgw-charging-profile ch1

Step 2

Enable RAT Type NB-IoT and LTE-M.

gtpp-attributes additional-rat-type [lte-m nb-iot]

Note

 

If additional-rat-type is not configured in sgw-charging-profile, CDRs generated for LTE-M/NB-IOT devices have RAT Type IE as EUTRAN only.

Step 3

Save and commit the configuration.

Troubleshooting Information for RAT-Type Support

This section provides output of show commands, clear commands, and bulk statistics that can be used to troubleshoot the issues.

Show Commands

  • Show running config output: To view additional-rat-type information, use the show full-configuration command. 

       [sgw] smf(config)# show full-configuration profile sgw-charging-profile ch1
profile sgw-charging-profile ch1
 gtpp-attributes additional-rat-type [lte-m nb-iot]
exit

  • Show subscriber config output: To view additional-rat-type subscriber information, use the show subscriber command. 

    [sgw] smf# show subscriber nf-service sgw rat lte-m
subscriber-details 
{
  "subResponses": [
    [
      "id-index:1:0:32768",
      "id-index-key:1:0:globalKey:32768",
      "id-value:16778240",
      "imsi:imsi-123456789012348",
      "msisdn:msisdn-223310101010101",
      "imei:imei-123456786666660",
      "rat:lte-m",
      "upf:10.1.44.42",
      "upfEpKey:10.1.44.42:10.1.45.167",
      "subscribertype:non-volte",
      "s5s8Ipv4:10.1.43.219",
      "s11Ipv4:10.1.44.42",
      "data-tunnel:IPV4",
      "namespace:sgw",
      "nf-service:sgw"
    ]
  ]
}

[sgw] smf# show subscriber nf-service sgw count rat nb-iot
Tue Apr  29 08:36:31.184 UTC+00:00
subscriber-details 
{
  "sessionCount": 1
}

Clear Commands

To clear the the additional-rat-type information for a subscriber, use the clear subscriber command. 

[sgw] smf# clear subscriber nf-service sgw rat lte-m

Example of message notification post running the clear subscriber command.

Example - Clear subscriber request submitted successfully for GR Instance ID 1. Waiting Time is 9.540360 seconds.

Bulk Statistics Output

This feature introduces the following changes to the statistics related to the SGW service:

  • New Label: rat_type

    • The rat_type label has been added to the following statistics:

      • sgw_service_stats

      • sgw_ue_disconnect_stats

    • This label indicates the Radio Access Technology (RAT) type used for the connection.

  • Modified rat_type values

    • The implementation has been modified to populate the rat_type label with values of nb-iot or lte-m in the following statistics:

      • sgw_ue_stats

      • sgw_pdn_stats

      • sgw_pdn_disconnect_stats

Here are examples of the updated statistics with the new rat_type label and the updated values:

  • sgw_service_stats

    sgw_service_stats{app_name="smf",cluster="Local",
data_center="DC",fail_reason="",gr_instance_id="1",instance_id="0",
interface="interface_sgw_egress",rat_type="LTE-M",reject_cause="",
service_name="sgw-service",sgw_procedure_type="initial_attach",
status="attempted",sub_fail_reason="",svc_to_svc="False"} 1

  • sgw_ue_stats

    sgw_ue_stats{app_name="smf",cluster="Local",
data_center="DC",gr_instance_id="1",instance_id="0",
rat_type="LTE-M",service_name="sgw-service",status="setup"} 1

  • sgw_pdn_stats

    sgw_pdn_stats{app_name="smf",cluster="Local",
data_center="DC",gr_instance_id="1",instance_id="0",
pdn_plmn_type="visitor",pdn_type="ipv4",rat_type="LTE-M",
service_name="sgw-service",status="setup"} 1

  • sgw_ue_disconnect_stats

    sgw_ue_disconnect_stats{app_name="smf",cluster="Local",
data_center="DC",gr_instance_id="1",instance_id="0",peer_ip="",
rat_type="LTE-M",reason="remote_init_disconnect",service_name="
sgw-service"} 1

  • sgw_pdn_disconnect_stats

    sgw_pdn_disconnect_stats{app_name="smf",cluster="Local",
data_center="DC",gr_instance_id="1",instance_id="0",pdn_type="ipv4",
rat_type="LTE-M",reason="mme_init_pdn_sess_rel",service_name=
"sgw-service"} 1