PCRF Sy interface

Hi Experts
Getting to know Sy Interface can solve low balance issue and recharge (PCRF to OCS)
==>Is there any one to describe to me Sy interface can solve the low balance issue Using Diameter Technical Details is that possible Sy interface can check low balance and recharge ?

Sy Interface (PCRF<​–​>OCS)

Use of Sy interface between PCRF and OCS is quite significant. It could help to maintain subscriber quota information in a central location like OCS. Traditional method is to maintain the subscriber’s quota information in SPR (Subscriber Profile Repository) which is a copy (Duplicate) of the OCS in most scenarios. Correct implementation of Sy can be use to eliminate the need of SPR.

Typical use of the SPR is to store the quota information of the PCRF subscribers where PCRF will use these quota information to enforce the QOS on PDP or bearer. Most popular use case is FUP (Fair User Policy) based on consumed data volumes. Many operators tends to configure FUP specially on unlimited data plans to maintain the their yield healthier and make sure that few of the heavy users will not rule the experience of other subscribers.

Operators who are keen to keep the quota information in central location such as OCS, can use Sy interface to achieve the same thing even by eliminating the SPR. In fact this will also help operator to eliminate the provisioning need of SPR. In most common scenarios whenever subscribers purchase a data plan, the provisioning has to be done at several places such as in billing system (OCS) and SPR (PCRF) etc. If we can use the Sy integration with OCS and PCRF then SPR provisioning can be ignore. This will greatly help the operator to reduce the ‘time to market’ of their products.

Major Parameter use in Sy interface is called ‘Policy Counter’. There can be several types of policy counter such as numeric type and string type. As you can guess the numeric policy counter will transfer numeric values and string type will deal with some word or string. Policy Counter has to be created in both OCS end and PCRF end. In OCS end policy counter may also bind with one or more quota. (Depends on the Sy implementation of the OCS vendor). When ever some modification (Recharge, Bill Payment) happened to the quota of the subscriber OCS will inform the change to the PCRF (SNR Spending-Limit-Status-Notification Request) by using appropriate policy counter.

At the PCRF level the received value or the string of the policy counter will be used to take the decisions such as QOS change. So the real time QOS adjustment can be achieved based on the real time quota status. At the same time PCRF has the ability to check the status of the required policy counter at the start of the PDP or bearer sessions by sending the SLR-I message. (Spending-Limit-Status-Request).