Reduction in paging traffic in GNB using near real-time ran intelligent controller XAPP
An Open Radio Access Network (O-RAN) communication system includes a GNB Central Unit Control Plane (GNB-CUCP) to establish a connection with a Near-RT RIC via an E2 interface; a User Equipment (UE); a plurality of cells in a Tracking Area (TA) of the GNB-CUCP; and an O-RAN Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) to host an xApp and initiate a subscription procedure with the UE. The GNB-CUCP sends cell location information of the UE to the Near-RT RIC upon a UE context release procedure, the Near-RT RIC creates and maintains a record of the cell location information received from the GNB-CUCP via the xApp, and the GNB-CUCP pages the UE in a subset of cells from the plurality of cells in the TA, the subset of cells corresponding to the record of cell location information created and maintained by via the xApp.
1 . A method of optimizing paging a User Equipment (UE) in an Open Radio Access Network (O-RAN) communication system, the method comprising:
establishing an E2 connection between a GNB Central Unit Control Plane (GNB-CUCP) and an O-RAN Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) hosting an xApp;
initiating a UE subscription procedure by the Near-RT RIC;
sending by the GNB-CUCP cell location information of the UE to the Near-RT RIC upon a UE context release;
creating and maintaining a record of cell locations where the UE was attached via the xApp;
retrieving a current list of cell location information from the Near-RT RIC xApp by the GNB-CUCP;
storing by the GNB-CUCP the current list of cell location information; and
paging, by the GNB-CUCP, the UE in a subset of cells corresponding to the current record of cell location information, wherein the subset of cells is a subset of the cells in a Tracking Area (TA) of the GNB-CUCP.
2 . The method according to claim 1 , wherein the cell location of the UE is ascertained according to a 5G-Serving Temporary Mobile Subscriber Identity (5G-S-TMSI) and New Radio (NR) Cell Global Identifier (NCGI).
3 . The method according to claim 2 , wherein the GNB-CUCP sends the 5G-S-TMSI and NCGI in an Experimental E2 Application Protocol (E2AP) indication.
4 . The method according to claim 3 , wherein the xApp creates and maintains a 5G-S-TMSI record based on the E2AP indication.
5 . The method according to claim 4 , wherein the GNB retrieves a current 5G-S-TMSI and NCGI list via a RIC Control Request.
6 . The method according to claim 5 , wherein the GNB-CUCP stores the 5G-S-TMSI received in the RIC Control Request.
7 . The method according to claim 1 , further comprising paging the UE in all cells of the TA of the GNB when a paging retry timer expires.
8 . The method according to claim 6 , wherein paging the UE is based on a new Experimental E2 Service Model (E2SM).
9 . The method according to claim 1 , wherein the GNB-CUCP receives a Next Generation Application Protocol (NGAP) paging message from an Access Mobility Function (AMF).
10 . An Open Radio Access Network (O-RAN) communication system comprising:
a GNB Central Unit Control Plane (GNB-CUCP) configured to establish a connection with a Near-RT RIC via an E2 interface;
a plurality of cells in a Tracking Area (TA) of the GNB-CUCP; and
an O-RAN Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) hosting an xApp and configured to initiate a subscription procedure with a User Equipment (UE), wherein
the GNB-CUCP is configured to send cell location information of the UE to the Near-RT RIC upon a UE context release procedure, wherein
the Near-RT RIC is further configured to create and maintain a record of the cell location information received from the GNB-CUCP via the xApp, and wherein
the GNB-CUCP is configured to retrieve a current list of cell location information from the xApp, store the current list of cell location information, and page the UE in a subset of cells corresponding to the current record of cell location information, wherein the subset of cells is from the plurality of cells in the TA.
11 . The O-RAN communication system according to claim 10 , wherein the cell location information is established according to a 5G-Serving Temporary Mobile Subscriber Identity (5G-S-TMSI) and New Radio (NR) Cell Global Identifier (NCGI).
12 . The O-RAN communication system according to claim 11 , wherein the GNB-CUCP sends the 5G-S-TMSI and NCGI in an Experimental E2 Application Protocol (E2AP) indication.
13 . The O-RAN communication system according to claim 12 , wherein the xApp creates and maintains a 5G-S-TMSI/NCGI record based on the E2AP indication.
14 . The O-RAN communication system according to claim 13 , wherein the GNB-CUCP retrieves a current 5G-S-TMSI/NCGI list via a RIC Control Request.
15 . The O-RAN communication system according to claim 14 , wherein the GNB-CUCP stores the 5G-S-TMSI/NCGI received in the RIC Control Request.
16 . The O-RAN communication system according to claim 10 , wherein the GNB-CUCP is further configured to page the UE in all cells of the TA of the GNB-CUCP upon expiration of a paging retry timer.
17 . The O-RAN communication system according to claim 15 , wherein paging the UE is based on a new Experimental E2 Service Model (E2SM).
18 . The O-RAN communication system according to claim 10 , further comprising an Access Mobility Function (AMF), wherein the GNB-CUCP receives a Next Generation Application Protocol (NGAP) paging message from the AMF.