Network Initiated UPF Sessions Transfer

Abstract

A first network node receives, from a second network node, at least one first message indicating a status of the second network node. The first network node determines, based on the status, to transfer a plurality of sessions for a plurality of wireless devices from the second network node to a third network node. The first network node sends, to the third network node, a second message indicating an establishment request of the plurality of sessions for the plurality of wireless devices. The second message comprises session identifiers of the plurality of sessions.

What is claimed is: 
     
         1 . A first network node, comprising:
 one or more processors; and   memory storing instructions that, when executed by the one or more processors, cause the first network node to perform operations comprising:
 receiving, from a second network node, at least one first message indicating a status of the second network node; 
 determining, based on the status, to transfer a plurality of sessions for a plurality of wireless devices from the second network node to a third network node; and 
 sending, to the third network node, a second message indicating an establishment request of the plurality of sessions for the plurality of wireless devices, wherein the second message comprises session identifiers of the plurality of sessions. 
   
     
     
         2 . The first network node of  claim 1 , wherein the operations further comprise:
 receiving, from the third network node, a third message indicating a result of the establishment request; and   sending, to the second network node and based on the result, a fourth message indicating release of at least one session of the plurality of sessions, wherein the fourth message comprises at least one session identifier of the at least one session.   
     
     
         3 . The first network node of  claim 2 , wherein the third message comprises at least one of:
 uplink fully qualified tunnel endpoint identifiers for the plurality of sessions; or   downlink fully qualified tunnel endpoint identifiers for the plurality of sessions.   
     
     
         4 . The first network node of  claim 2 , wherein the result indicates that establishment of one or more sessions of the plurality of sessions failed. 
     
     
         5 . The first network node of  claim 2 , wherein the operations further comprise receiving, from the second network node, a fifth message indicating a response to the fourth message. 
     
     
         6 . The first network node of  claim 1 , wherein the operations further comprise receiving, from a first network function, the at least one first message indicating a status of the second network node, wherein the first network function comprises at least one of:
 an operation and maintenance function; or   a policy control function.   
     
     
         7 . The first network node of  claim 1 , wherein the first message further comprises a first parameter indicating a request for transferring sessions of one or more UPFs, wherein the first parameter comprises at least one of:
 a UPF identifier of the second network node;   the session identifiers of the plurality of sessions;   location information of the second network node;   a data network name of the second network node;   a packet data unit session type of the plurality of sessions;   a quality of service;   a fully qualified connection set identifier;   a single network slice selection assistance information of the plurality of sessions; or   a data network access identifier of the second network node.   
     
     
         8 . The first network node of  claim 1 , wherein the first message further comprises a second parameter comprising traffic load information of one or more sessions of the second network node, wherein the traffic load information comprises at least one of:
 a session identifier;   a fully qualified connection set identifier;   a usage report;   an error indication report;   load control information;   overload control information; or   an additional usage reports information.   
     
     
         9 . The first network node of  claim 1 , wherein the first message further comprises a third parameter comprising node information of the second network node, wherein the node information comprises at least one of:
 a node identifier;   a fully qualified connection set identifier;   a node report type;   a user plane path failure report;   a usage report for sessions; or   an overload report.   
     
     
         10 . The first network node of  claim 1 , wherein the operations further comprise sending, to a second network function, a third message comprising downlink fully qualified tunnel endpoint identifiers of the third network node for the plurality of sessions. 
     
     
         11 . The first network node of  claim 10 , wherein the operations further comprise receiving, from the second network function and in response to the third message, a fourth message comprising uplink fully qualified tunnel endpoint identifiers of the second network function for the plurality of sessions. 
     
     
         12 . The first network node of  claim 10 , wherein the second network function comprises at least one of:
 a packet data unit session anchor user plan function; or   an egress network function, wherein the egress network function is an intermediate UPF and/or PDU session anchor UPF.   
     
     
         13 . The first network node of  claim 1 , wherein the operations further comprise:
 sending, to a third network function, a third message comprising uplink fully qualified tunnel endpoint identifiers of the third network node for the plurality of sessions; and   receiving, from the third network function and in response to the third message, a fourth message comprising downlink fully qualified tunnel endpoint identifiers of the third network function for the plurality of sessions.   
     
     
         14 . The first network node of  claim 13 , wherein the third network function comprises an ingress network function, and the ingress network function comprises an intermediate UPF. 
     
     
         15 . The first network node of  claim 1 , wherein the plurality of sessions comprises:
 at least one first session of a first wireless device; and   at least one second session of a second wireless device.   
     
     
         16 . The first network node of  claim 1 , wherein the operations further comprise:
 sending, to the third network node, a third message comprising:
 an uplink fully qualified tunnel endpoint identifier of a second network function for the plurality of sessions; and 
 a downlink fully qualified tunnel endpoint identifier of a third network function for the plurality of sessions; and 
   receiving, from the third network node and in response to the third message, a fourth message for the plurality of sessions.   
     
     
         17 . The first network node of  claim 1 , wherein the operations further comprise:
 sending, to a fourth network function, a third message comprising uplink fully qualified tunnel endpoint identifiers of the third network node for the plurality of sessions; and   receiving, from the fourth network function and in response to the third message, a fourth message comprising a downlink fully qualified tunnel endpoint identifier of a fifth network function for the plurality of sessions.   
     
     
         18 . The first network node of  claim 17 , wherein the operations further comprise:
 sending, by the fourth network function to the fifth network function, a seventh message comprising uplink fully qualified tunnel endpoint identifiers of the third network node for the plurality of sessions; and   receiving, by the fourth network function from the fifth network function and in response to the seventh message, an eighth message comprising downlink fully qualified tunnel endpoint identifiers of the fifth network function for the plurality of sessions.   
     
     
         19 . The first network node of  claim 18 , wherein the fourth network function comprises an access and mobility management function, and the fifth network function comprises at least one access network. 
     
     
         20 . The first network node of  claim 1 , wherein the operations further comprise:
 receiving, from a unified data management and/or a policy control function, a third message comprising transfer priority information; and   employing the transfer priority information to transfer the plurality of sessions from the second network node to the third network node.