Subscription based 5G session validation

1 . A Binding Support Function (BSF) system, comprising:

one or more processors; and

a memory having stored thereon instructions that, upon execution by the one or more processors, cause the one or more processors to:

create a binding record associated with a 5G communication session;

receive a subscription request from a Policy Control Function (PCF) for a session revalidation event associated with the 5G communication session;

initiate a revalidation timer based on the subscription request;

send a notification request to the PCF based on the revalidation timer expiring;

delete the binding record based on a response to the notification request, including:

increment a failure count value when no response to the notification request is received; and

delete the binding record when the failure count exceeds a threshold value.

2 . The BSF system of claim 1 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

receive the response to the notification request;

delete the binding record based on the response indicating the 5G communication session is invalid; and

restart the revalidation timer based on the response indicating the 5G communication session is valid.

3 . The BSF system of claim 2 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

register a Network Function (NF) profile with a Network Repository Function (NRF) indicating support for session revalidation.

4 . The BSF system of claim 3 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

restart the revalidation timer when no response to the notification request is received and the failure count does not exceed the threshold value.

5 . The BSF system of claim 3 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

resend the notification request when no response to the notification request is received and the failure count does not exceed the threshold value.

6 . The BSF system of claim 5 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

receive an Rx protocol message associated with the 5G communication session and directed to the PCF;

route the Rx protocol message to the PCF;

receive a response to the Rx protocol message from the PCF; and

restart the revalidation timer based on the response to the Rx protocol message.

7 . The BSF system of claim 6 , wherein a duration of the revalidation timer is set by an operator of the BSF.

8 . The BSF system of claim 7 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

associate the binding record with a PCFset of multiple PCFs including the PCF; and

send the notification request to another PCF in the PCFset when the PCF is unavailable.

9 . The BSF system of claim 8 , wherein the instructions comprise further instructions that, upon execution by the one or more processors, cause the one or more processors to:

delete the binding record when each PCF in the PCF set is unavailable, or returns an unexpected response indicating neither that the 5G communication session is invalid or valid.

10 . A method comprising:

operating a Binding Support Function (BSF) of a mobile network, including:

creating a binding record associated with a 5G communication session;

receiving a subscription request from a Policy Control Function (PCF) for a session revalidation event associated with the 5G communication session;

initiating a revalidation timer based on the subscription request;

sending a notification request to the PCF based on the revalidation timer expiring;

deleting the binding record based on a response to the notification request, including:

incrementing a failure count value when no response to the notification request is received; and

deleting the binding record when the failure count exceeds a threshold value.

11 . The method of claim 10 , further comprising:

receiving the response to the notification request;

deleting the binding record based on the response indicating the 5G communication session is invalid; and

restarting the revalidation timer based on the response indicating the 5G communication session is valid.

12 . The method of claim 10 , further comprising:

registering a Network Function (NF) profile with a Network Repository Function (NRF) indicating support for session revalidation.

13 . The method of claim 10 , further comprising:

restarting the revalidation timer when no response to the notification request is received and the failure count does not exceed the threshold value.

14 . The method of claim 10 , further comprising:

resending the notification request when no response to the notification request is received and the failure count does not exceed the threshold value.

15 . The method of claim 10 , further comprising:

receiving an Rx protocol message associated with the 5G communication session and directed to the PCF;

routing the Rx protocol message to the PCF;

receiving a response to the Rx protocol message from the PCF; and

restarting the revalidation timer based on the response to the Rx protocol message.

16 . The method of claim 10 , wherein a duration of the revalidation timer is set by an operator of the BSF.

17 . The method of claim 10 , further comprising:

associating the binding record with a PCFset of multiple PCFs including the PCF; and

sending the notification request to another PCF in the PCFset when the PCF is unavailable.

18 . The method of claim 17 , further comprising:

deleting the binding record when each PCF in the PCF set is unavailable, or returns an unexpected response indicating neither that the 5G communication session is invalid or valid.