Mobile point-to-point protocol

• US 6,917,600 B1
• Filed: 06/15/2000
• Issued: 07/12/2005
• Est. Priority Date: 05/08/1998
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Rai, Girish, Chuah, Mooi Choo
• Primary Examiner(s): Ho, Duc
• Assistant Examiner(s): Nguyen, Phuongchau Ba
• Application Number:
  US09/595,347
• Time in Patent Office: 1,853 Days
• Field of Search: 370/328, 370/331, 370/332, 370/335, 370/353, 370/401, 370/467, 455/421, 455/423, 4554321-442
• US Class Current: 370/328
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 2012/5667 IP over ATM
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 63/0272 Virtual private networks
• 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 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0033 with transfer of context information
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 76/22 Manipulation of transport tunnels
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/14 Backbone network devices

Abstract

Apparatus for transferring packet data incorporates a “hand-off” feature that allows the transfer of an existing PPP connection from one packet server to another packet server. Such a hand-off control message or call continue transaction can be initiated by any of the servers involved in the transactions. For instance, assume an initial arrangement where a point-to-point call is set up and in progress between a user and a private network via a first packet server (e.g., a first Serving LAC) and a second packet server (e.g., an Anchor LAC). If, for example, the user moves out of the region served by the first packet server into a region served by a third packet server (e.g., a second Serving LAC), then a hand-off control message transaction, according to the invention, is initiated. Either the second Serving LAC or the Anchor LAC may initiate the call continue transaction. Alternatively, radius servers respectively associated with the packet servers may be employed to perform the call continue transaction. Furthermore, assuming that a communication path is not yet established between the second packet server (e.g., Anchor LAC) and the third packet server (e.g., the second Serving LAC), a communication path (e.g., tunnel), set-up control message transaction may be performed concurrent with the call continue transaction. Still further, at least one packet server (e.g., the Anchor LAC) monitors state variables associated with the packet servers (e.g., the second Serving LAC and the private network) from which it receives packet data.

Claims

1. Apparatus comprising packet equipment configured to be responsive to a hand-off notification associated with an existing wireless data call associated with a point-to-point protocol connection by transmitting a message signal to a packet server, the message signal including a communication path set-up request and a continued call request for establishing, in accordance with a modified layer two tunneling protocol, a communication path with the packet server for the existing wireless data call, such that a tunnel establishment process and a hand-off process are concurrently initiated, and such that the existing wireless data call is not dropped.

2. The apparatus of claim 1, wherein the packet equipment is a network access server.

3. The apparatus of claim 1, wherein the packet equipment is configured for receiving another message signal from the packet server, the other message signal being responsive to the communication path set-up request and the continued call request.

4. The apparatus of claim 3, wherein the packet equipment is configured for transmitting a second message signal to the packet server, the second message signal being responsive to the message signal received from the packet server.

5. Apparatus comprising packet equipment configured to permit an existing wireless point-to-point protocol connection with a first packet server to be transferred to a second packet server, the packet equipment initiating the transfer in response to a hand-off notification associated with the existing point-to-point protocol connection, the packet equipment being further configured for establishing a tunnel in accordance with a modified layer two tunnel protocol to the second packet server to convey packets from a source which previously conveyed packets over a tunnel established between the first packet server and the packet equipment such that the existing point-to-point connection need not be reestablished.

6. The apparatus of claim 5, wherein the packet equipment is configured to be responsive to signaling received from the second packet server.

7. The apparatus of claim 6, wherein the packet equipment is configured for transmitting signaling responsive to the signaling received from the second packet server.

8. The apparatus of claim 5, wherein the packets are encapsulated in another packet.

9. The apparatus of claim 5, wherein the packet equipment is configured for transmitting a message signal to the second packet server, the message signal including a communication path set-up request and a continued call request for establishing a communication path with the second packet server for the existing point-to-point protocol connection.

10. Apparatus comprising packet equipment associated with a first radius server and configured to be responsive to a hand-off notification associated with an existing wireless data call of a point-to-point protocol connection by transmitting a message signal to packet equipment associated with a second radius server, the message signal including a continued call request for establishing, in accordance with a modified layer two tunneling protocol, a communication path between a first packet server operatively coupled to the first radius server and a second packet server operatively coupled to the second radius server such that the existing wireless data call is not dropped.

11. The apparatus of claim 10, wherein the packet equipment associated with the first radius server is configured for receiving a message signal from the packet equipment associated with the second radius server, the message signal being responsive to the continued call request.

12. The apparatus of claim 11, wherein the packet equipment associated with the first radius server is configured for transmitting a second message signal to the packet equipment associated with the second radius server, the second message signal being responsive to the message signal received from the packet equipment associated with the second radius server.

13. A method for use in a packet server comprising the steps of:

receiving a hand-off notification for a wireless call associated with a point-to-point protocol connection to a first packet server;

transmitting a message signal to a second packet server including a communication path set-up request and a continued call request for establishing, in accordance with a modified layer two tunneling protocol, a communication path with the second packet server such that a tunnel establishment process and a hand-off process are concurrently initiated; and

completing the hand-off for the wireless call by subsequently transmitting packets to the second packet server such that the wireless call is not dropped.