Address acquisition

• US 20050271034A1
• Filed: 07/18/2005
• Published: 12/08/2005
• Est. Priority Date: 01/20/2000
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Hurtta, Tuija, Asokan, Nadarajah, Soininen, Jonne L., Rajaniemi, Jaakko, Hippelainen, Lassi
• Granted Patent: US 7,920,575 B2
• Time in Patent Office: Days
• US Class Current: 370/349
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5046 Resolving address allocation conflicts; Testing of addresses testing when self-assigning an address H04L61/5092
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 61/5092 by self-assignment, e.g. picking addresses at random and testing if they are already in use
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/167 Adaptation for transition between two IP versions, e.g. between IPv4 and IPv6 translation of Internet protocol [IP] addresses H04L61/2503
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals

Abstract

In a GPRS system, a method of a mobile station acquiring an IP network address. The method comprises the steps of: the mobile station generating a link identifier and sending it to a gateway over a wireless link in a network address request together with a request to check if the link identifier is unique; the gateway receiving the network address request and checking if the link identifier is unique; the gateway responding with a network address request response including either the sending a unique link identifier confirmed as being unique or a different unique link identifier; the gateway sending a network prefix to the mobile station; the mobile station combining the interface identifier and the network prefix to generate the IP network address.

Claims

1. A method of acquiring a network address in a communications network, the method comprising the steps of:

establishing an entity comprising information on network addresses within a subnetwork;

creating a link with a link identifier unique within the subnetwork between the first node and the second node;

determining a network address for the first node on the basis of the link identifier;

checking by the entity whether the determined network address is unique; and

accepting the network address if the determined network address is unique.

2. A method according to claim 1 in which the link identifier is generated statically based on information identifying one of the nodes.

3. A method according to claim 1 in which the link identifier is generated randomly by one of the nodes.

4. A method according to claim 1 in which the information on network addresses is a list of link identifiers or network addresses in the subnetwork.

5. A method according to claim 4 in which the list comprises link identifiers which have previously been assigned to nodes.

6. A method according to claim 5 in which uniqueness checking is accomplished by the entity referring to the list of previously assigned link identifiers or network addresses.

7. A method according to claim 6 in which uniqueness checking is carried out by the entity referring to a routing table.

8. A method according to claim 6 in which uniqueness checking is carried out by the entity referring to a neighbour cache.

9. A method according to claim 4 in which the list comprises link identifiers which are unique and has not previously been assigned.

10. A method according to claim 9 in which uniqueness checking is accomplished by the gateway selecting a link identifier or a network address from the list of link identifiers or network addresses which have not yet been assigned.

11. A method according to claim 1 in which the information is that the entity has an identifier which is can used to create a unique network address.

12. A method according to claim 11 in which uniqueness checking is accomplished by the entity referring to the information on network addresses it contains and determining that it has a link identifier which can used to create a unique network address.

13. A method according to claim 1 in which the link identifier is transferred between the first and the second nodes from a sender to a recipient.

14. A method according to claim 13 in which the recipient of the link identifier discards it and generates a different link identifier which is checked for uniqueness.

15. A method according to claim 13 in which if the link identifier is not unique, the recipient chooses a unique link identifier which it sends to the sender.

16. A method according to claim 1 in which the network address is derived from the link identifier and a network prefix.

17. A method according to claim 16 in which the network prefix is obtained by means of a router solicitation sent between the first and second nodes.

18. A method according to claim 16 in which the network prefix is obtained by means of a router advertisement which is sent automatically between the first and the second node.

19. A method according to claim 1 in which there are a plurality of network prefixes used to create a plurality of network addresses for a node.

20. A method according to claim 1 in which the communications network comprises a plurality of subnetworks.

21. A method according to claim 1 in which the first node is a mobile station.

22. A method according to claim 1 in which the second node is a gateway.

23. A method according to claim 1 in which the communications network is a GPRS system.

24. A method according to claim 12 in which the link is a PDP context.

25. A method according to claim 1 in which the network address is a IPv6 address.

26. A communications network comprising:

a subnetwork;

a first node and a second node;

an entity comprising information on network addresses within the subnetwork, the entity being able to create a link with a link identifier unique within the subnetwork between the first node and the second node and to determine a network address for the first node on the basis of the link identifier;

wherein the entity is able to check whether the determined network address is unique and to accept the network address if the determined network address is unique.

27. A mobile terminal to operate with the communications network of claim 26.

28. A method of a node acquiring an IP network address in a communications system, the method comprising:

the node sending a network address request to a gateway over a wireless link requesting a unique interface identifier;

the node receiving the interface identifier and a confirmation from the gateway that the interface identifier is unique;

the node adopting the interface identifier;

the node receiving a network prefix from the gateway; and

the node combining the interface identifier and the network prefix to produce the IP network address.

29. A method of acquiring a network address in a communications network, the method comprising:

creating a link with a link identifier unique within a subnetwork between a first node and a second node;

determining a network address for the first node on, the basis of the link identifier;

checking whether the determined network addresss is unique; and

accepting the network address if the determined network address is unique.