Delivery of short messages in a packet radio network

A method for delivering short messages to a mobile station operating in two different networks capable of delivering short messages, one of the networks being a primary network and the other one being a secondary network so that attempts to reach the mobile station are primarily made through the primary network first, and the mobile station may be attached to the primary and secondary network simultaneously, the method comprising:

• providing a subscriber database with information on whether a mobile station is reachable through a primary network,
• receiving a routing information request at a subscriber database,
• sending an address in the primary network and optionally an address in a secondary network as a routing information response, if the mobile station is reachable through the primary network, and
• sending an address in the secondary network as a routing information response, if the mobile station is not reachable through the primary network.

A cellular packet radio system, comprising:

• at least one mobile station,
• at least one packet radio support node connected to a digital cellular radio network offering to said at least one packet radio support node a radio interface for packet-switched data transfer with said at least one mobile station,
• at least one gateway mobile switching center for short message service connected to the at least one packet radio support node and to the digital cellular radio network for delivery of short messages to the at least one mobile station,
• at least one home location register for maintaining routing addresses for the at least one mobile station,
• the at least one gateway mobile switching center for short message service to deliver a mobile-terminated short message primarily through a serving packet radio support node of a packet radio network using an address of the packet radio network and to attempt retransmission of the short message through the digital cellular radio network in response to a failure report message received from the serving packet radio support node if the home location register gives both network addresses,
• the digital cellular radio network pages the mobile station through the serving packet radio support node of the packet radio network each time the mobile station is simultaneously attached to both networks,
• wherein if the serving packet radio support node does not succeed in delivering the short message to the mobile station,
• the packet radio support node inserts into said failure report message sent to gateway mobile switching center for short message service information preventing the gateway mobile switching center from retransmitting the short message through the digital cellular radio network.

A cellular packet radio system, comprising:

• at least one mobile station that can be simultaneously attached to a packet radio network and a cellular radio network,
• at least one packet radio support node connected to a digital cellular radio network offering to said at least one packet radio support node a radio interface for packet-switched data transfer with said at least one mobile station,
• at least one home location register storing information on which networks the mobile station is attached to, wherein
• the support node of the packet radio network sends information to the digital cellular radio network when the mobile station becomes attached to the digital cellular radio network through the support node, and
• the digital cellular radio network, in response to receipt of said information from the packet radio support node, clears the indication possibly held in its registers on the fact that the mobile station could not be reached and not to send to the home location register an indication of the attach of the mobile station to the cellular radio network.

A cellular packet radio system, comprising:

• at least one mobile station that can be simultaneously attached to a packet radio network and a cellular radio network,
• at least one packet radio support node connected to a digital cellular radio network offering to said at least one packet radio support node a radio interface for packet-switched data transfer with said at least one mobile station,
• at least one home location register storing information on which networks the mobile station is attached to, wherein
• the support node of the packet radio network sends a message to the digital cellular radio network when the mobile station becomes attached to the digital cellular radio network through the support node, said message containing information on the fact that the indication possibly held in the registers of the digital cellular radio network of the fact that the mobile station could not be reached is to be cleared, and
• the digital cellular radio network, in response to receipt of said information from the packet radio support node, clears the indication possibly held in its registers of the fact that the mobile station could not be reached and not to send to the home location register an indication of the attach of the mobile station to the cellular radio network.

A cellular packet radio system, comprising at least one mobile station,

• at least one packet radio support node connected to a digital cellular radio network offering to said at least one support node a radio interface for packet-switched data transfer with said at least one mobile station,
• at least one gateway mobile switching center for short message service connected to the packet radio support node and to the digital cellular radio network for delivery of short messages to the at least one mobile station,
• at least one home location register for maintaining routing addresses and subscriber data for mobile stations,
• the home location register gives the address of the packet radio network and the address of the cellular radio network in response to a mobile-terminated short message routing information inquiry when the mobile station is attached to both networks, the home location register gives only the address of the packet radio network or the address of the cellular radio network in response to a mobile-terminated short message routing information inquiry when the mobile station is attached to the packet radio network or to the cellular radio network only,
• the gateway mobile switching center for short message service delivers a mobile-terminated short message primarily through the serving packet radio support node of the packet radio network using the address of the packet radio network, if the home location register gives both addresses,
• the gateway mobile switching center for short message service delivers a mobile-terminated short message through the packet radio network or through the cellular radio network only, if the home location register gives the address of the packet radio network or the address of the cellular radio network only,
• wherein if the packet radio support node does not succeed in delivering the short message to the mobile station,
• the packet radio support node inserts into the failure report message sent to the gateway mobile switching center for short message service an indication of the fact that the mobile station cannot be reached through the packet radio network,
• the gateway mobile switching center for short message service, in response to said indication, inserts the same indication to the delivery report message sent to the home location register, and
• the home location register is adapted, in response to receipt of said indication, to store said indication in its registers,
• the home location register gives, in response to a routing information inquiry, the address of the digital cellular radio network only when said indication is stored in the subscriber data for the mobile station, even though the mobile station were attached to both networks.

A cellular radio network, comprising:

• a primary network offering a first data transfer route,
• at least one network node in the primary network,
• a secondary network offering a second data transfer route,
• at least one mobile station that can be simultaneously attached to the primary network and to the secondary network,
• at least one gateway mobile switching center for short message service connected to the primary network and to the secondary network for delivery of short messages to the mobile stations,
• at least one home location register for maintaining routing addresses and subscriber data for mobile stations,
• the home location register gives the address in the primary network and optionally the address in the secondary network in response to a mobile-terminated short message routing information inquiry when the mobile station is attached to both networks,
• the home location register gives only the address in the primary network or the address in the secondary network in response to a mobile-terminated short message routing information inquiry when the mobile station is attached to the primary network or to the secondary network only,
• the gateway mobile switching center for short message service delivers a mobile-terminated short message primarily through the network node of the primary network using the address in the primary network, if the home location register gives both addresses,
• the gateway mobile switching center for short message service delivers a mobile-terminated short message through the primary network or only through the secondary network, if the home location register gives the address of the primary network or only the address of the secondary network,
• wherein if the network node does not succeed in delivering the short message to the mobile station,
• the network node inserts into the failure report message sent to the gateway mobile switching center for short message service an indication of the fact that the mobile station cannot be reached through the primary network,
• the gateway mobile switching center for short message service, in response to said indication, inserts the same indication into the delivery report message sent to the home location register, and
• the home location register, in response to receipt of said indication, stores said indication in its registers,
• the home location register gives, in response to a routing information inquiry, the address of the secondary network only when said indication is stored in the subscriber data for the mobile station, even though the mobile station were attached to both networks.

A subscriber data base in a telecommunication system, which comprises:

• two different networks capable of delivering short messages to a mobile station operating in the two networks, one of the networks being a primary network and the other one being a secondary network so that attempts to reach the mobile station are primarily made through the primary network first for delivering short messages to the mobile station, and the mobile station may be attached to the primary and secondary network simultaneously, the subscriber database comprising subscriber data, routing information and sending means for sending a response to a routing information request, wherein
• the subscriber database comprises memory means for maintaining reachability information on whether the mobile station is reachable through the primary network, and
• the sending means are responsive to reachability information and include into the response to the routing information request
• an address in the primary network and optionally an address in the secondary network, if the mobile station is reachable through the primary network, or
• an address in the secondary network, if the mobile station is not reachable through the primary network.

A cellular packet radio system, comprising:

• at least one mobile station,
• a digital cellular radio network offering a radio interface for data transfer with said
• at least one mobile station,
• at least one packet radio support node connected to the digital cellular radio network,
• at least one gateway mobile switching center for short message service connected to the packet radio support node and to the digital cellular radio network for delivery of short messages to the mobile station,
• at least one home location register for maintaining routing addresses for the mobile station,
• the gateway mobile switching center for short message service to deliver a mobile-terminated short message primarily through the serving packet radio support node of the packet radio network using the address of the packet radio network and to attempt retransmission of the short message through the digital cellular radio network in response to a failure report message received from the packet radio support node if the home location register gives both addresses,
• wherein if the packet radio support node does not succeed in delivering the short message to the mobile station, the packet radio support node inserts into said failure report message information preventing the gateway mobile switching center for short message service from retransmitting the short message through the digital cellular radio network and to send said failure report message to said gateway mobile switching center for short message service.