GRAN access port addressing method and apparatus

• US 6,151,495 A
• Filed: 10/08/1998
• Issued: 11/21/2000
• Est. Priority Date: 10/10/1997
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Rune, Johan
• Primary Examiner(s): Kuntz, Curtis A.
• Assistant Examiner(s): Taylor, Barry W.
• Application Number:
  US09/168,715
• Time in Patent Office: 775 Days
• Field of Search: 455/428, 455/461, 455/445, 455/426, 455/432, 370/230, 370/401, 370/338, 370/95.3
• US Class Current: 455/426.1
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 88/12 Access point controller devices
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

The present invention relates generally to the problem of finding the correct access port when an access attempt is made by a subscriber belonging to a core network that can not change access port for a particular subscriber. For core networks without support for terminal mobility, a certain subscriber is always accessed through the same access port. If a user moves far away from his "home access port" the access attempt will be unnecessarily rejected because the GRAN normally routes the connection to the closest access port. The present invention solves this problem by placing mapping tables in the IWUs to map core network subscriber identities to access port addresses. This mapping information is then used to route the access attempt to the correct access port. If the subscriber identity does not belong to either the accessed access port nor is it listed on the mapping table, the user is considered outside his allowed area and the access attempt is rejected.

Claims

1. In a Generic Radio Access Network (GRAN) serving as a possible information bearer to a plurality of core networks, wherein each of said core networks has at least one subscriber having a mobile terminal and wherein at least one type of subscriber mobile terminal consists of one GRAN specific part that logically belongs to the GRAN and one core network specific part that logically belongs to the core network, a method for redirecting a core network access request transmitted by a core network subscriber terminal from a first access port to a second access port wherein at least the second access port is connected to said subscriber'"'"'s core network, comprising the steps of:

receiving, at a first interworking unit (IWU) connected to said first access port, a request for access to said subscriber'"'"'s core network from said subscriber terminal wherein said request is included and transferred, uninterpreted by the GRAN as part of an initial message;

transmitting, from said first IWU to a first radio network controller (RNC), the address to the second access port;

redirecting, from said first RNC, said request for access to said subscriber'"'"'s core network to the second access port according to the address received from the first IWU.

2. The method of claim 1, wherein the step of redirecting is initiated upon reception of said access request in said first IWU, wherein access to the subscriber'"'"'s core network by the subscriber terminal is allowed only through at least one predetermined access point and the at least one predetermined access point is not connected to said first IWU.

3. The method of claim 1, wherein said second access port is said subscriber'"'"'s home access port, and wherein said core network does not provide mobility to subscriber terminals.

4. The method of claim 1, wherein the step of receiving said request for access in a first IWU further comprises receiving an initial message requesting a signaling connection to said core network.

5. The method of claim 1, wherein said first access port is connected to the first RNC, the first RNC serving a first plurality of base stations, wherein one of said first plurality of base stations receives said access request with a higher reception quality than any of a second plurality of base stations connected to a plurality of other RNCs.

6. The method of claim 1, wherein said subscriber terminal is not allowed to communicate with said subscriber'"'"'s core network via said first access port.

7. The method of claim 1, wherein said subscriber terminal transmits a core network subscriber identity as a part of said access request.

8. The method of claim 7 further comprising the step of comparing, in said first IWU, said core network subscriber identity with a list of core network subscriber identities, wherein said list of identities represents subscriber identities allowed to access said core network through said first access port.

9. The method of claim 8, wherein said core network subscriber identity is not represented in said list of core network subscriber identities and said transmitting step further comprises the steps of:

correlating, in said first IWU, said core network subscriber identity with a mapping table, wherein said mapping table is a list of subscriber identities and, corresponding to said subscriber identities, network addresses to allowed access ports for communication with said core network; and

reporting to said first RNC a corresponding address to an allowed access port for said core network subscriber identity for redirecting said access request.

10. The method of claim 9, wherein said first access port is connected to said subscriber'"'"'s core network.

11. In a Generic Radio Access Network (GRAN) serving as a possible information bearer to a plurality of core networks, wherein each of said core networks has at least one subscriber having a mobile terminal and wherein at least one type of subscriber terminal consists of one GRAN specific part that logically belongs to the GRAN, one core network specific part that logically belongs to the core network, and an interworking part, a method for redirecting a core network access request from a first access port to a second access port wherein at least the second access port is connected to said subscriber'"'"'s core network, wherein the core network access request is received from a core network subscriber terminal, the method comprising the steps of:

receiving, at a first interworking unit (IWU) connected to said first access port, a request for access to said subscriber'"'"'s core network from said subscriber terminal;

transmitting, from said first IWU to a first radio network controller (RNC), an address to the second access port;

returning, from said first RNC to said subscriber terminal, the address to the second access port.

12. The method of claim 11, wherein said second access port is said subscriber'"'"'s home access port, and wherein said core network does not provide mobility to subscriber terminals.

13. The method of claim 11, wherein the step of receiving said request for access in a first IWU further comprises receiving an initial message requesting a signaling connection to said core network.

14. The method of claim 11, wherein said first access port is connected to the first RNC, the first RNC serving a first plurality of base stations, wherein one of said first plurality of base stations receives said access request with a higher reception quality than any of a second plurality of base stations connected to a plurality of other RNCS.

15. The method of claim 11, wherein said subscriber terminal is not allowed to communicate with said subscriber'"'"'s core network via said first access port.

16. The method of claim 11, wherein said subscriber terminal uses said address to said second access port to initiate a second core network access attempt addressed to said second access port.

17. The method of claim 16, wherein said subscriber terminal transmits a core network subscriber identity as a part of said access request.

18. The method of claim 17 further comprising the step of comparing, in said first IWU, said core network subscriber identity with a list of core network subscriber identities, wherein said list of identities represents subscriber identities allowed to access said core network through said first access port.

19. The method of claim 18, wherein said core network subscriber identity is not represented in said list of core network subscriber identities, further comprising the steps of:

correlating, in said first IWU, said core network subscriber identity with a mapping table, wherein said mapping table is a list of subscriber identities and, corresponding to said subscriber identities, network addresses to allowed access ports for communication with said core network; and

wherein the step of returning said address to the second access port comprises the step of reporting to said first subscriber terminal a corresponding address to an allowed access port for said network subscriber identity for redirecting said access request.

20. The method of claim 19, wherein said first access port is connected to said subscriber'"'"'s core network.

21. The method of claim 11, wherein the interworking part of the subscriber terminal stores the address of the correct access port to be used in subsequent access attempts by the same user in the same GRAN.

22. In a Generic Radio Access Network (GRAN) wherein a core network does not support mobility, a method of directing an access attempt by a user terminal having a core network specific part, a GRAN specific part, and an interworking part comprising the steps of:

attempting to access the core network from the user terminal through a closest one of a plurality of access ports;

establishing signaling between the interworking part of the terminal and an interworking unit (IWU) at the closest access port to which said core network is connected, wherein a request for signaling is included and transferred, uninterpreted by the GRAN as part of an initial message;

transferring the core network subscriber identity from the interworking part of the terminal to the IWU at the closest access port;

checking, at said IWU, to determine if said subscriber identity belongs to the closest access port;

establishing a connection between the core network specific part of the terminal and the core network if said subscriber identity belongs to said closest access port;

checking a mapping table in said IWU at the closest access port for the correct access port that maps to the subscriber identity if the subscriber identity does not belong to said closest access port, said mapping table mapping core network subscriber identities to access port addresses;

rejecting the access attempt if the subscriber identity is not on said mapping table; and

if the subscriber identity is located on said mapping table, performing the steps of;

retrieving the correct access port address from the table;

returning the correct access port address to the interworking part of the terminal;

releasing said signaling between the core network specific part of the terminal and the IWU; and

performing a new access attempt from said terminal, using the correct access port.

23. In a Generic Radio Access Network (GRAN) wherein a core network does not support mobility, a system used for directing an access attempt by a user terminal having a core network specific part and a GRAN specific part, comprising:

means for the user terminal attempting to access the core network through a closest one of a plurality of access ports using an initial message to a closest radio network controller (RNC) in the GRAN, said initial message requesting a signaling connection to the core network and wherein a request for signaling is included and transferred. uninterpreted by the GRAN as part of an initial message;

means for sending a core network subscriber identity of the user terminal as a part of said initial message;

means for transferring by said RNC the request for a signaling connection, including said core network subscriber identity, to an interworking unit (IWU) at the closest access port, wherein said core network is connected to the closest access port;

means for said IWU at said closest access port to determine if said subscriber identity belongs to said closest access port;

means for establishing a connection between the core network specific part of the terminal and the core network if the subscriber identity belongs to the closest access port;

means for checking a mapping table in said IWU at the closest access port for a correct access port address that corresponds to the subscriber identity, said mapping table mapping core network subscriber identities to access port addresses;

means for rejecting the access attempt if the subscriber identity is not on the mapping table;

means for the IWU retrieving the correct access port address from the mapping table if the subscriber identity is on the mapping table;

means for the IWU returning the correct access port address to the RNC; and

means for the RNC rerouting the access attempt to the correct access port.

24. In a Generic Radio Access Network (GRAN) wherein a core network does not support mobility, a system for directing an access attempt by a user terminal having a core network specific part, a GRAN specific part, and an interworking part, comprising:

terminal means for attempting to access the core network through a closest one of a plurality of access ports;

means for establishing signaling between the interworking part of the terminal and an interworking unit (IWU) at the closest access port, wherein said core network is connected to the closest access port;

means for the interworking part of the terminal transferring a core network subscriber identity for the user terminal to the IWU at the closest access port;

means for said IWU to determine if said subscriber identity belongs to the closest access port;

means for establishing a connection between the core network specific part of the terminal and the core network if the subscriber identity belongs to the closest access port;

means for checking a mapping table in said IWU at the closest access port for a correct access port address that corresponds to the subscriber identity, said mapping table mapping core network subscriber identities to access port addresses;

means for rejecting the access attempt if the subscriber identity is not on the mapping table;

means for retrieving, by said IWU, the correct access port address from the mapping table if the subscriber identity is on the mapping table;

means for the IWU to return the correct access port address to the interworking part of the terminal;

means for releasing the signaling between the interworking part of the terminal and the IWU; and

means for said terminal performing a new access attempt, using the correct access port address.