Remote API - Modify EPS Bearer

The purpose of this tutorial is to show you how to change Modify EPS Bearer using Remote API.  If you are not familiar with the basic operation of Remote API, I would suggest you to look into this tutorial first.

The purpose of the Modify EPS Bearer command in LTE is to modify certain parameters of an existing EPS Bearer. Followings are some of the importants contents of Modify EPS Bearer message (based on 24.301-Table 8.3.18.1).

• Quality of service (QoS)
• QoS Class Identifier (QCI),
• Maximum Bit Rate
• Guranteed Bit Rate
• Traffic Flow Template (TFT)
• Radio Priority
• Packet Flow Identifier
• Protocol Configuration Options (PCO)

Table of Contents

• Remote API - Modify EPS Bearer
• Test Setup
• Key Configuration Parameters
• Configuration
• Perform the test

Test Setup

Key Configuration Parameters

Followings are important configuration parameters for this tutorial. You may click on the items for the descriptions from Amarisoft documents.

• ue_modify_bearer : In this link, you will get the description for all the items listed below.
• imsi
• imei
• erab_id
• qos
• qci
• priority_level
• pre_emption_capability
• pre_emption_vulnerability
• gbr
• filters
• llc_sapi
• radio_priority
• packet_flow_identifier
• sm_qos
• p_cscf
• dns
• erabs : In this link, you will get the description for all the items listed below.
• qci
• priority_level
• pre_emption_capability
• pre_emption_vulnerability

Configuration

You can use any of LTE configuration for this tutorial (e.g, enb.default.cfg).

Perform the test

Power on UE and wait until Attach is complete as below (run the command 'ue' in (mme) screen to get this result). Make it sure that at least one or more IP address is assigned to UE.

Execute the following Remote API to get the basic information that you need for ue_modify_bearer

You will get the result as shown below if UE is properly attached. Remember imsi and erab_id because it will be used in the RetmoteAPI command to modify the bearer.

For now, QCI is assigned to be 9 as shown in the log. In this test, I will change this QCI value to 6 using a Remote API.

Run the RemoteAPI command as shown below. (NOTE : the "imsi", "imei","erab_id" should be set accordingly based on your specific test.)

./ws.js mme '{"message": "ue_modify_bearer","imsi":"001010123456789","imei":"869057056356291","erab_id":5,

    "qos":

        {

          "qci": 6,

          "priority_level": 15,

          "pre_emption_capability": "shall_not_trigger_pre_emption",

          "pre_emption_vulnerability": "not_pre_emptable"

        }

       }'

If your command has been successfully processed, you will get the response as follows.

Confirm that the Bearer is changed as intended in the log. In this example, you see that 'Modify EPS bearer context request' is sent to UE with 'New EPS QoS' IE as specified in the Remote API.