Optimization of MTC Device Trigger Delivery

Abstract

A network node ( 21 ), which is placed within a core network, stores a list of network elements ( 24 ) capable of forwarding a trigger message to a MTC device ( 10 ). The network node ( 21 ) receives the trigger message from a transmission source ( 30, 40 ) placed outside the core network, and then selects, based on the list, one of the network elements to forward the trigger message to the MTC device ( 10 ). The MTC device ( 10 ) validates the received trigger message, and then transmits, when the trigger message is not validated, to the network node ( 21 ) a reject message indicating that the trigger message is not accepted by the MTC device ( 10 ). Upon receiving the reject message, the network node ( 21 ) forwards the trigger message through a different one of the network elements, or forwards the reject message to transmission source ( 30, 40 ) to send the trigger message through user plane.

1 . A network node placed within a core network, comprising:
 a storage unit that stores a list of network elements capable of forwarding a trigger message to a MTC (Machine-Type-Communication) device attached to the core network, the trigger message being received from a transmission source placed outside the core network; and   a selection unit that selects, based on the list, one network element to which a path is not marked as invalid to securely forward the trigger message to the MTC device.   
     
     
         2 . The network node according to  claim 1 ,
 wherein the storage unit is configured to:   download information of the network elements from a server; and   create the list by use of the downloaded information,   wherein the downloading and the creation are performed prior to a reception of the trigger message.   
     
     
         3 . The network node according to  claim 1 ,
 wherein the list is created by a server based on information of the network elements, and   wherein the storage unit is configured to download the list from the server, and   wherein the downloading is performed prior to a reception of the trigger message.   
     
     
         4 . The network node according to  claim 1 ,
 wherein in the list, the network elements are stored in association with their respective usage rates, and   wherein the selection unit is configured to select, as said one network element, the network elements in ascending order of usage rate.   
     
     
         5 . The network node according to  claim 1 , wherein the selection unit is configured to check whether or not said one network element can securely forward the trigger message to the MTC device, by pinging said one network element or analyzing information on said one network element received from a server. 
     
     
         6 . The network node according to  claim 1 , wherein the network node comprises an MTC-IWF (MTC-Interworking Function), a GGSN (Gateway GPRS (General Packet Radio Service) Support Node), or a P-GW (PDN (Packet data network) Gateway). 
     
     
         7 . A MTC (Machine-Type-Communication) device attached to a core network, and configured to receive a trigger message forwarded by the network node according to  claim 1 . 
     
     
         8 . A network node placed outside a core network, and configured to transmit a trigger message to the network node according to  claim 1 . 
     
     
         9 . The network node according to  claim 8 , wherein the network node placed outside the core network comprises an SCS (Services Capability Server) or an SME (Short Message Entity). 
     
     
         10 . A method of controlling a network node that is placed within a core network and that forwards a trigger message to a MTC (Machine-Type-Communication) device attached to the core network, a transmission source of the trigger message being placed outside the core network, the method comprising:
 storing a list of network elements capable of forwarding the trigger message to the MTC device; and   selecting, based on the list, one network element to which a path is not marked as invalid to securely forward the trigger message to the MTC device.   
     
     
         11 - 44 . (canceled) 
     
     
         45 . The method according to  claim 10 , further comprising:
 downloading information of the network elements from a server; and   creating the list by use of the downloaded information,   wherein the downloading and the creation are performed prior to a reception of the trigger message.   
     
     
         46 . The method according to  claim 10 , further comprising:
 downloading the list from a server, the list being created by the server based on information of the network elements,   wherein the downloading is performed prior to a reception of the trigger message.   
     
     
         47 . The method according to  claim 10 ,
 wherein in the list, the network elements are stored in association with their respective usage rates, and   wherein the selection is performed by selecting, as said one network element, the network elements in ascending order of usage rate.   
     
     
         48 . The method according to  claim 10 ,
 wherein the selection includes checking whether or not said one network element can securely forward the trigger message to the MTC device, by pinging said one network element or analyzing information on said one network element received from a server.