CA2359040C - Methods and system for inter packet data serving node (pdsn) handover and mobility in a cdma2000 network - Google Patents
Methods and system for inter packet data serving node (pdsn) handover and mobility in a cdma2000 network Download PDFInfo
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- CA2359040C CA2359040C CA002359040A CA2359040A CA2359040C CA 2359040 C CA2359040 C CA 2359040C CA 002359040 A CA002359040 A CA 002359040A CA 2359040 A CA2359040 A CA 2359040A CA 2359040 C CA2359040 C CA 2359040C
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/12—Reselecting a serving backbone network switching or routing node
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Abstract
The invention relates to methods for enabling handover for Simple IP or Mobile IP in a CDMA2000 network. In one embodiment, the new PDSN (17) establishes contact with the old PDSN (16) to obtain information about its PPP
connection with the MN (11). The new PDSN (17) then sets up a tunnel between the PDSNs (16-17) and copies the PPP connection, while the old PDSN (16) dismounts its own PPP connection. The traffic now goes from the MN (11) to the new PDSN (17) that tunnels it to the old PDSN (16) that in turn forwards it through its old connection to the HA (20) or the backbone (22).
In a second embodiment, the new PDSN (17) contacts the old PDSN (16) to obtain information about the connections associated with the MN (11), and uses the information to copy the connections, while keeping contact with the old PDSN (16) to update the same information.
Also provided are systems and PDSNs (16-17) for carrying out the methods according to the inventions.
Suggested publication figure: Figure 3.
connection with the MN (11). The new PDSN (17) then sets up a tunnel between the PDSNs (16-17) and copies the PPP connection, while the old PDSN (16) dismounts its own PPP connection. The traffic now goes from the MN (11) to the new PDSN (17) that tunnels it to the old PDSN (16) that in turn forwards it through its old connection to the HA (20) or the backbone (22).
In a second embodiment, the new PDSN (17) contacts the old PDSN (16) to obtain information about the connections associated with the MN (11), and uses the information to copy the connections, while keeping contact with the old PDSN (16) to update the same information.
Also provided are systems and PDSNs (16-17) for carrying out the methods according to the inventions.
Suggested publication figure: Figure 3.
Description
R I CSSON ~ 02359040 2001-09-27 : 51 4 3457929 ..
PATENT APPLICATION
DOCKET NO. P139a3CA
METHODS AND SYSTEM FOR INTER PACKET DATA SERVING NODE (PDSN) z o BACKGROUND OF THE INVENTION
The present invention relates to radio telecommunication and more particularly to systems and methods for handover between Packet Data Serving Nodes (PDSNs) in a CDMA2000 network.
T~e~crinti~n ~f Rela . Art Figure 1 shows a simplified block diagram for a Prior Art CDMA2000 (Code Division Multiple Access 2000) network 10, providing packet-switched call routing through Packet Data Serving Nodes (PDSN) 16-17.
'The packet data network 10 provides services to a number of mobile nodes ao (MN) 11-I2 (a CDMA2000 designation for mobile station) that access the network I0 through a number of Radio Networks (RN) 13-14 via the air interface 15. The RNs 13-14 link to a number of PDSNs 16-17 using a Radio Packet (R-P) interface 18, often but not necessarily over a first IP network 21. The MNs 11-connect, over the underlying interfaces, to the PDSNs 16-17 using a Point to
PATENT APPLICATION
DOCKET NO. P139a3CA
METHODS AND SYSTEM FOR INTER PACKET DATA SERVING NODE (PDSN) z o BACKGROUND OF THE INVENTION
The present invention relates to radio telecommunication and more particularly to systems and methods for handover between Packet Data Serving Nodes (PDSNs) in a CDMA2000 network.
T~e~crinti~n ~f Rela . Art Figure 1 shows a simplified block diagram for a Prior Art CDMA2000 (Code Division Multiple Access 2000) network 10, providing packet-switched call routing through Packet Data Serving Nodes (PDSN) 16-17.
'The packet data network 10 provides services to a number of mobile nodes ao (MN) 11-I2 (a CDMA2000 designation for mobile station) that access the network I0 through a number of Radio Networks (RN) 13-14 via the air interface 15. The RNs 13-14 link to a number of PDSNs 16-17 using a Radio Packet (R-P) interface 18, often but not necessarily over a first IP network 21. The MNs 11-connect, over the underlying interfaces, to the PDSNs 16-17 using a Point to
2 5 Point Protocol {PPP} connection 24, as symbolically shown at the bottom of the figure. The PDSNs I6-17 are, for example, used as access concentrators, concentarating the received transmissions before forwarding them over a second IP
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network 19. This second IP network 19 is among other things connected to the backbone network 22 with access to other networks (not shown) or directly to said other networks. It is through this second IP network 19 that the PDSNs 16-may connect to the Home Agent (HA) 20, the function of which will be partly described below. An Authentication, Authorisation and Accounting (AAA) server 30 is connected to the rest of the network 10 through the second IP network 19.
The AAA server 30 is contacted in many instances that deal with security and billing, such as for example during the set up of new PPP connections. It is to be understood that the PDSNs 16-17 may use the same HA 20 or different ones (of which only one is shown in Figure 1).
The CDMA2000 network 10 described above is able to provide the mobile user with two different packet data services, Simple IP and Mobile IP. In Simple IP, the user is provided with a dynamic IP address from the local FDSN and IP
routing service is provided by a service provider network. The user retains this IP
1 s address as long as the PDSN remains in connection with the RN the user is served by. This means that handover, retaining active sessions, between different PDSNs is not possible, which is a major problem with Simple IP. It is, of course, possible for a MN to roam from one PDSN to another, but doing so means losing any active sessions.
a o In Mobile IP howevex, inter-PDSN handover is possible. This is owing to the fact that the Home Agent (HA) 20 acts as a kind of fix reference point for the MN 11-12. When the MN 11-12 receives packets from the outside, these packets are sent to the HA 20, as the HA 20 is associated with the MN 11--12, and the packets are sent from the HA 20 to the proper PDSN 16-17 that in turn forwards SRICSSON ;5~4 3457929 v ~ , PATENT APPLICATION
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the packets to the MN 11-12. Therefore, inter-PDSN handover is made possible by the fact that the HA 20 keeps track of where the MN 1 I-I2 is located.
As mentioned earlier, there is a PPP connection 24 between a MN 1I-12 and a PDSN 16-I7, while the further connection 25 is a Mobile IP (MIP) connection in case of Mobile IP, and a normal IP connection or the like in case of Simple IP.
The inter-PDSN handover procedure for Mobile IP according to the Prior Art is shown in Figure 2, which shows a MN 11, two PDSNs I6-17 and a HA 20, as in figure 1. At first, with reference to Figure 2a, there exists a PPP
connection a. 0 24 between the MN 11 and the first PDSN 16, as well as a MIP (Mobile IP) connection 25 between then PDSN 16 and the HA 20. With reference to Figure 2b, to start the handover the PPP connection 24 is terminated and a new PPP
connection 26 is created between the MN I1 and the second PDSN 17. Then, Figure 2c, the MIP connection 25 between the first PDSN 16 and the HA 20 is replaced by a new MIP connection 27 between the second PDSN 17 and the HA
20. As can be seen, there is now a connection between the MN 11 and the HA 20 going through the second PDSN 17 instead of the first PDSN 16. As mentioned earlier, there are no Prior Art handover methods for Simple IP.
Setting up a new connection is fairly cumbersome, as there is a lot of 2 o signalling back and forth, often negotiating various connection options.
There are for example in PPP at least three different phases to go through: link set-up {governed by the Link Connection Protocol - LCP), authentication (governed by the Challenge Handshake Authentication Protocol - CHAP), and network level configuration (governed by the IP Control Protocol - IPCP). A MIP connection is
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network 19. This second IP network 19 is among other things connected to the backbone network 22 with access to other networks (not shown) or directly to said other networks. It is through this second IP network 19 that the PDSNs 16-may connect to the Home Agent (HA) 20, the function of which will be partly described below. An Authentication, Authorisation and Accounting (AAA) server 30 is connected to the rest of the network 10 through the second IP network 19.
The AAA server 30 is contacted in many instances that deal with security and billing, such as for example during the set up of new PPP connections. It is to be understood that the PDSNs 16-17 may use the same HA 20 or different ones (of which only one is shown in Figure 1).
The CDMA2000 network 10 described above is able to provide the mobile user with two different packet data services, Simple IP and Mobile IP. In Simple IP, the user is provided with a dynamic IP address from the local FDSN and IP
routing service is provided by a service provider network. The user retains this IP
1 s address as long as the PDSN remains in connection with the RN the user is served by. This means that handover, retaining active sessions, between different PDSNs is not possible, which is a major problem with Simple IP. It is, of course, possible for a MN to roam from one PDSN to another, but doing so means losing any active sessions.
a o In Mobile IP howevex, inter-PDSN handover is possible. This is owing to the fact that the Home Agent (HA) 20 acts as a kind of fix reference point for the MN 11-12. When the MN 11-12 receives packets from the outside, these packets are sent to the HA 20, as the HA 20 is associated with the MN 11--12, and the packets are sent from the HA 20 to the proper PDSN 16-17 that in turn forwards SRICSSON ;5~4 3457929 v ~ , PATENT APPLICATION
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the packets to the MN 11-12. Therefore, inter-PDSN handover is made possible by the fact that the HA 20 keeps track of where the MN 1 I-I2 is located.
As mentioned earlier, there is a PPP connection 24 between a MN 1I-12 and a PDSN 16-I7, while the further connection 25 is a Mobile IP (MIP) connection in case of Mobile IP, and a normal IP connection or the like in case of Simple IP.
The inter-PDSN handover procedure for Mobile IP according to the Prior Art is shown in Figure 2, which shows a MN 11, two PDSNs I6-17 and a HA 20, as in figure 1. At first, with reference to Figure 2a, there exists a PPP
connection a. 0 24 between the MN 11 and the first PDSN 16, as well as a MIP (Mobile IP) connection 25 between then PDSN 16 and the HA 20. With reference to Figure 2b, to start the handover the PPP connection 24 is terminated and a new PPP
connection 26 is created between the MN I1 and the second PDSN 17. Then, Figure 2c, the MIP connection 25 between the first PDSN 16 and the HA 20 is replaced by a new MIP connection 27 between the second PDSN 17 and the HA
20. As can be seen, there is now a connection between the MN 11 and the HA 20 going through the second PDSN 17 instead of the first PDSN 16. As mentioned earlier, there are no Prior Art handover methods for Simple IP.
Setting up a new connection is fairly cumbersome, as there is a lot of 2 o signalling back and forth, often negotiating various connection options.
There are for example in PPP at least three different phases to go through: link set-up {governed by the Link Connection Protocol - LCP), authentication (governed by the Challenge Handshake Authentication Protocol - CHAP), and network level configuration (governed by the IP Control Protocol - IPCP). A MIP connection is
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also a rather complex matter.
It follows that some problems with the handover in CDMA2000 networks are that Simple IP handover retaining active sessions is not possible, and that Mobile IP handover is quite complex and time consuming, owing to the need of setting up the various negotiations and signal exchanges described above.
The present invention seeks to overcome these problems in providing simple inter-PDSN handover methods for Simple IP and Mobile IP.
Throughout this application, it is assumed that the various nodes in the network can send messages and signals to the other nodes in the network even z o when there is no connection drawn between them in the drawings. This is owing to the fact that this enhances comprehension of the invention. A pexson skilled in the art will acknowledge that this does not put any limitations or constraints on the invention per se.
SUMMARY OF THE INVENTION
35 The present invention is directed to systems, methods and Packet Data Service Nodes (PDSNs) for inter-PDSN handover using Point-to-Point Protocol (PPP) in a CDMA2000 network.
In a first embodiment of the method, the CDMA2000 network comprises a mobile node (MN) and at least two PDSNs, where the MN is connected to a first a o of the PDSNs via a first PPP connection, and where the method comprising the steps of choosing the second PDSN to hand the MN over to, obtaining by the second PDSN information about the first PPP connection, establishing a second PPP connection from the MN to the second PDSN using the information,
DOCKET NO. P13903CT.~
also a rather complex matter.
It follows that some problems with the handover in CDMA2000 networks are that Simple IP handover retaining active sessions is not possible, and that Mobile IP handover is quite complex and time consuming, owing to the need of setting up the various negotiations and signal exchanges described above.
The present invention seeks to overcome these problems in providing simple inter-PDSN handover methods for Simple IP and Mobile IP.
Throughout this application, it is assumed that the various nodes in the network can send messages and signals to the other nodes in the network even z o when there is no connection drawn between them in the drawings. This is owing to the fact that this enhances comprehension of the invention. A pexson skilled in the art will acknowledge that this does not put any limitations or constraints on the invention per se.
SUMMARY OF THE INVENTION
35 The present invention is directed to systems, methods and Packet Data Service Nodes (PDSNs) for inter-PDSN handover using Point-to-Point Protocol (PPP) in a CDMA2000 network.
In a first embodiment of the method, the CDMA2000 network comprises a mobile node (MN) and at least two PDSNs, where the MN is connected to a first a o of the PDSNs via a first PPP connection, and where the method comprising the steps of choosing the second PDSN to hand the MN over to, obtaining by the second PDSN information about the first PPP connection, establishing a second PPP connection from the MN to the second PDSN using the information,
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establishing a connection from the second PDSN to the first PDSN, extending the PPP connection from the second PDSN to the first PDSN, and informing the MN
that the handover is complete.
In a second embodiment of the method, the CDMA2000 network further comprises an IP network that the first PDSN is connected to, the method comprising the steps of choosing the second PDSN to hand the MN over to, obtaining by the second PDSN information about the first PPP connection, obtaining by the second PDSN information about the first connection from the first PDSN to the IP network, establishing a second PPP connection from the MN
to the second PDSN using the information, establishing a connection from the second PDSN to the IP network, and informing the MN that the handover is complete.
A first embodiment of the system according to the invention comprises at least two PDSNs, where the MN is connected to the first PDSN through a PPP
m connection and at least one Radio Network (RN) being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which the PPP
connection is established, the RN choosing a second PDSN to hand over to. The second PDSN obtains information about the first PPP connection, uses the 2 o information to establish a second PPP connection between the MN to the second PDSN, establishes a connection from the second PDSN to the first PDSN, over which the second PDSN extends the PPP connection whereby the PPP connection runs from the MN to the first PDSN, and informs the MN that the handover is complete.
S
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A second embodiment of the system according to the invention comprises at least two PDSNs, where the MN is connected to the first PDSN through a first PPP connection and where the first PDSN has a connection with an IP network, and at least one Radio Network (RN), being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which protocols the PPP
connection is established, the RN choosing a second PDSN to hand over to. 'The second PDSN obtains information about the first PPP connection and the connection to the IP network, uses the information about the first PPP
connection Io to establish a second PPP connection between the MN and the second PDSN and a connection between the second PDSN and the IP network, and informs the MN
that the handover is complete.
A first embodiment of the PDSN for MN handover where the MN is handed over to the PDSN, where the PDSN obtains information about a Burst PPP
15 connection that connects the MN to a previous PDSN, uses the information to establish a second PPP connection to the MN, establishes a connection to the previous PDSN, extends the second PPP connection whereby the second PPP
connection runs from the MN to the previous PDSN, and informs the MN that the handover is complete.
2 o A second embodiment of the PDSN for MN handover where the MN is handed over to the PDSN from a second PDSN that is connected to an IP
network, where the PDSN obtains information about a first PPP connection that connects the MN to a previous PDSN, uses the information to establish a second PPP connection to the MN, establishes a connection to the second PDSN, obtains ;514 3457929 PATENT APPLICATION
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information about the connection between the second PDSN and the IP network, uses the information to establish a second connection with the IP network, and informs the MN that the handover is complete.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in conjunction with the accompanying drawings wherein:
FIG. 1 depicts a simplified block diagxam of a Prior Art CDMA2000 network;
FIG. 2a depicts a block diagram illustrating the connection status prior to inter-PDSN handover, for Mobile IP, in a CDMA2000 network according to the Prior Art;
FIG. 2b depicts a block diagram illustrating the connection status during inter-PDSN handover, for Mobile IP, in a CDMA2000 network according to the 1 s Prior Art;
FIG. 2c depicts a block diagxam illustrating the connection status aftex inter-PDSN handover, for Mobile IP, in a CDMA2000 network according to the Prior Art;
FIG. 3a shows a block diagxam illustrating inter-PDSN handover for 2 o Mobile IP according to a first preferred embodiment of the invention;
FAG. 3b shows a block diagram illustrating inter-PDSN handover for Mobile IP according to a first preferred embodiment of the invention;
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FIG. 4a shows a block diagram illustrating inter-PDSN handover for Simple IP according to the first preferred embodiment of the invention;
FIG. 4b shows a block diagram illustrating inter-PDSN handover for Simple IP according to the first preferred embodiment of the invention;
FIG. 5a shows a block diagram illustrating inter-PDSN handover for Mobile IP according to a second preferred embodiment of the invention;
FIG. 5b shows a block diagram illustrating inter-PDSN handover for Mobile IP according to a second preferred embodiment of the invention;
FIG. 5c shows a block diagram illustrating inter-PDSN handover for 1 o Mobile IP according to a second preferred embodiment of the invention;
FIG. 6a shows a block diagram illustrating inter-PDSN handover for Simple IP according to the second preferred embodiment of the invention;
FIG. 6b shows a block diagram illustrating inter-PDSN handover for Simple IP according to the second preferred embodiment of the invention; and FIG. 6c shows a block diagram illustrating inter-PDSN handover for Simple IP according to the second preferred embodiment of the invention;
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DETAILED DESCRIPTION OF EMBODIMENTS
Reference is now made to Figure 3, where two block diagrams 3a-3b illustrate logical connections during handover according to a first preferred embodiment of the invention. Figure 3a shows, using the reference numbers from s Figure l, the pre-handover situation for a Mobile Node (MN) 11, a first and a second Radio Network (RN) 13-14, a first and a second Packet Data Serving Node (PDSN) 16-17, and a Home Agent (HA) 20. The MN 11 and the PDSN 16 are connected via a symbolically shown PPP connection 24 (over the air interface 15 and the Radio Packet, R-P, interface 18) while the PDSN 16 and the HA 20 are s o connected via a Mobile IP (MIP) connection 25.
During the handover procedure, wherein the MN is at least handed over from the first PDSN 16 to the second PDSN 17, the second RN 14 is provided with the PDSN iP Address, i.e. the IP address associated with the MN 11, by the MN 11 itself in a message 41, or by a node in the system, e.g. the first RN 13 or 15 an MSC (not shown). To keep the PPP connection 24 during the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN 14 then selects which PDSN 16-17 to connect to (as in the example PDSN 17), in an accepted fashion according to the Prior Art. The second 2 o RN I4 also sends, included in the standard connection set-up messages 42, the PDSN IP Address it received earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as this makes it possible to begin setting up in parallel a new R-P connection 18 and an Layer 2 Tunnelling Protocol (L2TP) tunnel 28 from the second PDSN 17 to the first PDSN 16. The CA 02359040 2001-09-27 :514 3457929 PATENT APPLICATION
DOCKET NO. P139~3CA
PPP connection 24 between the MN 11 and the first PDSN 16 is terminated as well. Figuxe 3b shows the logical connection status at this point. The first PDSN
16 is now the anchor point for enabling mobility for the MN I 1.
The second PDSN 17 sends a new L2TP message 43, Fast L2TP Set-Up Request, to extend the PPP connection from the second PDSN 17 to the first PDSN 16. This message 43 contains information for both setting up the L2TP
tunnel 28 and for requesting information about the PPP and MIP connections for the MN 11. In response to the message above, the first PDSN 16 returns a Fast L2TP Set-Up Acknowledgement 44 containing the requested information. The 1o second PDSN 17 then sends a message 45 to the MN 11, indicating that the original PPP connection 24 (although, unbeknownst to the MN 11, it is now really called 24') is active again, after which the handover is performed.
Any communication data is now sent from the MN 11 to the second PDSN
17, that tunnels the data via L2TP or any other tunnelling scheme to the first 1 s PDSN I6, which in turn tunnels the data to the HA 20 via the MIP
connection 25.
It should be understood that any tunnelling scheme, such as for example MIP tunnelling, could be used between the two PDSNs 16-17, in which case the tunnel and the corresponding messages are changed accordingly. It is also to be understood that the signalling is not limited to the hereinbefore-mentioned a o messages, but that any number or type of messages could be used to transfer the necessary information.
Reference is now made to Figure 4, where two block diagrams 4a-4b illustrate logical connections during handover according to a first preferred embodiment of the invention for the case of Simple IP. Figure 4a shows, using the io CA 02359040 2001-09-27 : 5 t 4 3457929 PATENT APPLICATION
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reference numbers for similar elements from Figure 1, the pre-handover situation for a Mobile Node (MN) 11, a first and a second Radio Network (RN) 13-14, and a first and a second Packet Data Serving Node (PDSN) 16-17. There is also an IP
network 22. The MN 11 and the PDSN 16 are connected via a symbolically s shown PPP connection 24 (over the air interface 15 and the Radio Packet, R-P, interface 18) while the PDSN 16 and the iP network 22 are connected via an IP
connection 25.
During the handover, the second RN 14 is provided with the PDSN IP
Address, i.e. the IP address associated with the MN 11, by the MN 11 itself in to message 41, or by a node in the system, e.g. the first RN 13 or an MSC (not shown). To keep the PPP connection 24 during the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN 14 then selects which PDSN 16-17 to connect to (as in the example PDSN 17}, in an accepted fashion according to the Prior Art. The second RN 14 also sends, included in the standard connection set-up messages 42, the PDSN IP Address it received earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as this makes it possible to begin setting up in parallel a new R-P connection 18 and an Layer 2 Tunnelling a o Protocol (L2TP) tunnel 28 from the second PDSN 17 to the first PDSN 16.
The PPP connection 24 between the MN 11 and the first PDSN 16 is terminated as well. Figure 4b shows the logical connection status at this point. The first PDSN
16 is now the anchor point for enabling mobility for the MN 11.
The second PDSN 17 sends a new L2TP message 43, Fast L2TP Set-Up CA 02359040 2001-09-27 ; 51 4 3457929 PATENT APPLICATION
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Request, to extend the PPP connection from the second PDSN I7 to the first PDSN 16. This message contains information for both setting up the L2TP tunnel 28 and for requesting information about the PPP connection 24 for the MN 11.
In response to the message above, the first PDSN 16 returns a Fast L2TP Set-Up Acknowledgement 44 containing the requested information. The second PDSN
17 then sends a message 45 to the MN I1, indicating that the original PPP
connection 24 (although, unbeknownst to the MN 11, it is now really called 24') is active, after which the handover is done.
Any communication data is now sent from the MN 1 I to the second PDSN
17, that tunnels the data via L2TP or any other tunnelling scheme to the first PDSN 16, which in turn tunnels the data to the IP network 22 via the IP
connection 25.
It should be understood that any tunnelling scheme, for example MiP
tunnelling, could be used between the two PDSNs 16-17, in which case the tunnel z5 and the corresponding messages are changed accordingly. It is also to be understood that the signalling is not limited to the above-mentioned messages;
but that any number or type of messages could be used to transfer the necessary information.
Figure 5 illustrates in Figures 5a-5c a second preferred embodiment of z o handover for Mobile IP. Figure 5a shows the pre-handover situation for a Mobile Node (MN) I1, a first and a second Radio Network (RN) 13-I4, a first and a second Packet Data Serving Node (PDSN) 16-17, and a Home Agent (HA) 20.
The MN 1 I and the PDSN 16 are connected via a PPP connection 24 (over the air interface IS and the R-P interface I8) while the PDSN 1.6 and the HA are CA 02359040 2001-09-27 ; 5 1 4 3457929 PATENT APPLICATION
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connected via a MIP connection 25.
As previously, during the handover, the second RN 14 is provided with the PDSN IP Address by the MN 11 in message 41, or by a node in the system, e.g.
the first RN 13 ox an MSC (not shown). To keep the PPP connection 24 during s the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN i4 then selects which PDSN 16-17 to connect to {as in the example, PDSN 17), in an accepted fashion. The second RN 14 also sends, included in the standard set-up messages 42, the PDSN IP Address it received 1o earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as it makes it possible to begin in parallel setting up a new R-P
connection (not shown) and, for the second PDSN 17, to obtain, from the first PDSN 16 through a signalling link 29 shown in Figure Sb, information about the PPP and MIP connections 24 and 25, respectively, the information being sent in 15 at least one message 46. The information could for example be exchanged via L2TP tunnel control messages (as above) or any other suitable signalling messages. Figure Sb shows the logical connection status at this point.
There are two different possibilities as to the downloading of information from the first PDSN 16 to the second PDSN 17 described hereinbefore. One a o possibility is to download relevant information about the connections as quickly as possible after the information is requested by the second PDSN 17 in order to enable the handover, while all other information in the first PDSN 16 pertaining to the MN 11 is downloaded later. Using this possibility, the object is to make the first PDSN 16 superfluous after which the second PDSN 17 is the sole PDSN 16-;514 3457929 PATENT APPLICATION
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17 dealing the MN 11, and the connection 29 between the two PDSNs I6-17 is terminated. A second possibility is to download the connection information as quickly as possible after the information is requested by the second PDSN 17, while other information related to the MN 11, such as for example information s about services the MN 11 accesses, remains with the frst PDSN 16. In this case, the connection 29 between the PDSNs 16-17 is kept.
The second PDSN 17 then either establishes a new MIP connection with the HA 20 or copies the MIP connection 25 (the new connection denoted by 25' in Figure Sc) between the first PDSN 16 and the HA 20, after which the first 1 o PDSN 1 b terminates its own MIP connection 25 with the HA 20. The second PDSN 17 then sends a message 45 to the MN 11, indicating that the original PPP
connection 24 is active, after which the handover is done. Figure 5c shows the network at this point.
Communication data is then sent between the MN 11 and the HA 20 via the second PDSN 17 that copied at least the PPP connection 2~ via the first PDSN
Ib, with which it keeps contact in case it has not downloaded all the relevant informarion about the MN 11, as described above. As the second PDSN 17 simply copied at least the PPP connection 24, there was no need to fully re-establish at least the PPP connection 24, which gives an efficient handover 2 o procedure.
Figure 6 illustrates in Figures 6a-6c a second preferred embodiment of handover for Simple IP. Figure 6a shows the pre-handover situation for a Mobile Node (MN) 11, a first and a second Radio Network (RN) 13-14, a first and a second Packet Data Serving Node (PDSN) 16-17, and an IP network 22. The MN
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11 and the PDSN 16 are connected via a PPP connection 24 (over the air interface 15 and the R-P interface 18) while the PDSN 16 is connected to the IP network via an IP connection 25.
As previously, during the handover, the second RN 14 is provided with the PDSN IP Address by the MN 11 in message 41, or by a node in the system, e.g.
the first RN 13 or an MSC (not shown). To keep the PPP connection 24 during the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN 14 then selects which PDSN 16-17 to connect to (as in the a. o example, PDSN 17), in an accepted fashion. The second RN 14 also sends, included in the standard set-up messages 42, the PDSN IP Address it received earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as it makes it possible to begin in parallel setting up a new R-P
connection (not shown) and, for the second PDSN 17, to obtain, from the first 15 PDSN 16 through a signalling link 29 shown in Figure 6b, information about the PPP connection 24, the information being sent in at least one message 46. The information could fox example be exchanged via L2TP tunnel control messages (as hereinbefore) or any other suitable signalling messages. Figure 6b shows the logical connection status at this point.
2 o There are two different possibilities as to the downloading of information from the first PDSN 16 to the second PDSN 17 described hereinbefore. One possibility is to download relevant information about the connections as quickly as possible after the information is requested by the second PDSN 17 in order to enable the handover, while all other information in the first PDSN 16 pertaining CA 02359040 2001-09-27 ; 5 1 4 3457929 PATENT APPLICATION
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to the MN 11 is downloaded later. Using this possibility, the object is to make the first PDSN 16 superfluous after which the second PDSN 17 is the sole PDSN 16-17 dealing the MN 11, and the connection 29 between the two PDSNs 16-17 is terminated. A second possibility is to download the connection information as quickly as possible after the information is requested by the second PDSN I7, while other information related to the MN 11, such as for example information about services the MN 11 accesses, remains with the first PDSN 16. In this case, the connection 29 between the PDSNs 16-17 is kept.
The second PDSN 17 then either preferably establishes a new IP
1 o connection with the 1P network 22 or copies the l.P connection 25 (the new connection denoted by 25' in Figure 6c) between the first PDSN 16 and the IP
network 22, after which the first PDSN 16 terminates its own IP connection 25 with the IP network 22. The second PDSN 17 then sends a message 45 to the MN
11, indicating that the original PPP connection 24 is active, after which the handover is done. Figure 6c shows the network at this point.
Communication data is then sent between the MN 1 l and the IP network 22 via the second PDSN I7 that copied at least the PPP connection 24 via the first PDSN 16, with which it keeps contact in case it has not downloaded all the relevant information about the MN 11, as described above. As the second PDSN
a o I7 simply copied at least the PPP connection 24, there was no need to fully re-establish at least the PPP connection 24, which gives an efficient handover procedure.
There are two different options of handling the case where the MN 11 hands over to yet another, third, PDSN (not shown). The first option is simply to CA 02359040 2001-09-27 :514 3457929 PATENT APPLICATION
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apply the hereinbefore mentioned handover method one more time, in which case there will be a series of tunnels or connections 28, 29 leading from the new PDSN
through the previous to the first.
The second, preferable option is to inform the third PDSN {not shown) s about the identity of the first PDSN 16. In the first embodiment, the third PDSN
contacts the second PDSN 17 as in the description in order to receive information and to copy the PPP connection 24. The third PDSN also receives the identity of the first PDSN 16, for example from the MN 11 or the second PDSN I7. Then, the third PDSN sets up a link to the first PDSN 16 and takes over the PPP
1o connection 24 to the MN 11, while the second PDSN 17 terminates its connections 24, 28 or 29.
In the second embodiment, the procedure depends on whether the first PDSN 16 still retains information about the MN 11 or not. In case the first PDSN
16 does not retain any information about the MN 11, then the further handover a5 procedure is straightforward following the description above. If, however, the first PDSN 16 still retains some responsibility for the MN 11, the procedure is as described above, with some additions. The third PDSN (not shown) receives the identity of the first PDSN 16, for example from the MN 11 or the second PDSN
17. Then it sets up a connection 28, 29 with the first PDSN 16, after which the a o second PDSN 17 can terminate its connection 28, 29 with the first PDSN 16.
It is also to be understood that there is no absolute necessity to change both RN 13-14 and PDSN 16-17 during the handover. It is perfectly conceivable that a RN 13-14 might want to change PDSN 16-I7 for the MN 11, but the handover m CA 02359040 2001-09-27 ; 51 4 3457929 PATENT APPLICATION
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would follow the same steps as detailed above, except that there is no need for the MN 11 to change RN 1.3-14.
As can be seen from the description above, thexe are provided efficient handover methods for Simple IP and Mobile IP, that in the case of Simple IP
enables handover, and in the case of Mobile IP makes the handover more efficient.
Although several preferred embodiments of the method and system of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.
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establishing a connection from the second PDSN to the first PDSN, extending the PPP connection from the second PDSN to the first PDSN, and informing the MN
that the handover is complete.
In a second embodiment of the method, the CDMA2000 network further comprises an IP network that the first PDSN is connected to, the method comprising the steps of choosing the second PDSN to hand the MN over to, obtaining by the second PDSN information about the first PPP connection, obtaining by the second PDSN information about the first connection from the first PDSN to the IP network, establishing a second PPP connection from the MN
to the second PDSN using the information, establishing a connection from the second PDSN to the IP network, and informing the MN that the handover is complete.
A first embodiment of the system according to the invention comprises at least two PDSNs, where the MN is connected to the first PDSN through a PPP
m connection and at least one Radio Network (RN) being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which the PPP
connection is established, the RN choosing a second PDSN to hand over to. The second PDSN obtains information about the first PPP connection, uses the 2 o information to establish a second PPP connection between the MN to the second PDSN, establishes a connection from the second PDSN to the first PDSN, over which the second PDSN extends the PPP connection whereby the PPP connection runs from the MN to the first PDSN, and informs the MN that the handover is complete.
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A second embodiment of the system according to the invention comprises at least two PDSNs, where the MN is connected to the first PDSN through a first PPP connection and where the first PDSN has a connection with an IP network, and at least one Radio Network (RN), being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which protocols the PPP
connection is established, the RN choosing a second PDSN to hand over to. 'The second PDSN obtains information about the first PPP connection and the connection to the IP network, uses the information about the first PPP
connection Io to establish a second PPP connection between the MN and the second PDSN and a connection between the second PDSN and the IP network, and informs the MN
that the handover is complete.
A first embodiment of the PDSN for MN handover where the MN is handed over to the PDSN, where the PDSN obtains information about a Burst PPP
15 connection that connects the MN to a previous PDSN, uses the information to establish a second PPP connection to the MN, establishes a connection to the previous PDSN, extends the second PPP connection whereby the second PPP
connection runs from the MN to the previous PDSN, and informs the MN that the handover is complete.
2 o A second embodiment of the PDSN for MN handover where the MN is handed over to the PDSN from a second PDSN that is connected to an IP
network, where the PDSN obtains information about a first PPP connection that connects the MN to a previous PDSN, uses the information to establish a second PPP connection to the MN, establishes a connection to the second PDSN, obtains ;514 3457929 PATENT APPLICATION
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information about the connection between the second PDSN and the IP network, uses the information to establish a second connection with the IP network, and informs the MN that the handover is complete.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in conjunction with the accompanying drawings wherein:
FIG. 1 depicts a simplified block diagxam of a Prior Art CDMA2000 network;
FIG. 2a depicts a block diagram illustrating the connection status prior to inter-PDSN handover, for Mobile IP, in a CDMA2000 network according to the Prior Art;
FIG. 2b depicts a block diagram illustrating the connection status during inter-PDSN handover, for Mobile IP, in a CDMA2000 network according to the 1 s Prior Art;
FIG. 2c depicts a block diagxam illustrating the connection status aftex inter-PDSN handover, for Mobile IP, in a CDMA2000 network according to the Prior Art;
FIG. 3a shows a block diagxam illustrating inter-PDSN handover for 2 o Mobile IP according to a first preferred embodiment of the invention;
FAG. 3b shows a block diagram illustrating inter-PDSN handover for Mobile IP according to a first preferred embodiment of the invention;
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FIG. 4a shows a block diagram illustrating inter-PDSN handover for Simple IP according to the first preferred embodiment of the invention;
FIG. 4b shows a block diagram illustrating inter-PDSN handover for Simple IP according to the first preferred embodiment of the invention;
FIG. 5a shows a block diagram illustrating inter-PDSN handover for Mobile IP according to a second preferred embodiment of the invention;
FIG. 5b shows a block diagram illustrating inter-PDSN handover for Mobile IP according to a second preferred embodiment of the invention;
FIG. 5c shows a block diagram illustrating inter-PDSN handover for 1 o Mobile IP according to a second preferred embodiment of the invention;
FIG. 6a shows a block diagram illustrating inter-PDSN handover for Simple IP according to the second preferred embodiment of the invention;
FIG. 6b shows a block diagram illustrating inter-PDSN handover for Simple IP according to the second preferred embodiment of the invention; and FIG. 6c shows a block diagram illustrating inter-PDSN handover for Simple IP according to the second preferred embodiment of the invention;
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DETAILED DESCRIPTION OF EMBODIMENTS
Reference is now made to Figure 3, where two block diagrams 3a-3b illustrate logical connections during handover according to a first preferred embodiment of the invention. Figure 3a shows, using the reference numbers from s Figure l, the pre-handover situation for a Mobile Node (MN) 11, a first and a second Radio Network (RN) 13-14, a first and a second Packet Data Serving Node (PDSN) 16-17, and a Home Agent (HA) 20. The MN 11 and the PDSN 16 are connected via a symbolically shown PPP connection 24 (over the air interface 15 and the Radio Packet, R-P, interface 18) while the PDSN 16 and the HA 20 are s o connected via a Mobile IP (MIP) connection 25.
During the handover procedure, wherein the MN is at least handed over from the first PDSN 16 to the second PDSN 17, the second RN 14 is provided with the PDSN iP Address, i.e. the IP address associated with the MN 11, by the MN 11 itself in a message 41, or by a node in the system, e.g. the first RN 13 or 15 an MSC (not shown). To keep the PPP connection 24 during the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN 14 then selects which PDSN 16-17 to connect to (as in the example PDSN 17), in an accepted fashion according to the Prior Art. The second 2 o RN I4 also sends, included in the standard connection set-up messages 42, the PDSN IP Address it received earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as this makes it possible to begin setting up in parallel a new R-P connection 18 and an Layer 2 Tunnelling Protocol (L2TP) tunnel 28 from the second PDSN 17 to the first PDSN 16. The CA 02359040 2001-09-27 :514 3457929 PATENT APPLICATION
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PPP connection 24 between the MN 11 and the first PDSN 16 is terminated as well. Figuxe 3b shows the logical connection status at this point. The first PDSN
16 is now the anchor point for enabling mobility for the MN I 1.
The second PDSN 17 sends a new L2TP message 43, Fast L2TP Set-Up Request, to extend the PPP connection from the second PDSN 17 to the first PDSN 16. This message 43 contains information for both setting up the L2TP
tunnel 28 and for requesting information about the PPP and MIP connections for the MN 11. In response to the message above, the first PDSN 16 returns a Fast L2TP Set-Up Acknowledgement 44 containing the requested information. The 1o second PDSN 17 then sends a message 45 to the MN 11, indicating that the original PPP connection 24 (although, unbeknownst to the MN 11, it is now really called 24') is active again, after which the handover is performed.
Any communication data is now sent from the MN 11 to the second PDSN
17, that tunnels the data via L2TP or any other tunnelling scheme to the first 1 s PDSN I6, which in turn tunnels the data to the HA 20 via the MIP
connection 25.
It should be understood that any tunnelling scheme, such as for example MIP tunnelling, could be used between the two PDSNs 16-17, in which case the tunnel and the corresponding messages are changed accordingly. It is also to be understood that the signalling is not limited to the hereinbefore-mentioned a o messages, but that any number or type of messages could be used to transfer the necessary information.
Reference is now made to Figure 4, where two block diagrams 4a-4b illustrate logical connections during handover according to a first preferred embodiment of the invention for the case of Simple IP. Figure 4a shows, using the io CA 02359040 2001-09-27 : 5 t 4 3457929 PATENT APPLICATION
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reference numbers for similar elements from Figure 1, the pre-handover situation for a Mobile Node (MN) 11, a first and a second Radio Network (RN) 13-14, and a first and a second Packet Data Serving Node (PDSN) 16-17. There is also an IP
network 22. The MN 11 and the PDSN 16 are connected via a symbolically s shown PPP connection 24 (over the air interface 15 and the Radio Packet, R-P, interface 18) while the PDSN 16 and the iP network 22 are connected via an IP
connection 25.
During the handover, the second RN 14 is provided with the PDSN IP
Address, i.e. the IP address associated with the MN 11, by the MN 11 itself in to message 41, or by a node in the system, e.g. the first RN 13 or an MSC (not shown). To keep the PPP connection 24 during the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN 14 then selects which PDSN 16-17 to connect to (as in the example PDSN 17}, in an accepted fashion according to the Prior Art. The second RN 14 also sends, included in the standard connection set-up messages 42, the PDSN IP Address it received earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as this makes it possible to begin setting up in parallel a new R-P connection 18 and an Layer 2 Tunnelling a o Protocol (L2TP) tunnel 28 from the second PDSN 17 to the first PDSN 16.
The PPP connection 24 between the MN 11 and the first PDSN 16 is terminated as well. Figure 4b shows the logical connection status at this point. The first PDSN
16 is now the anchor point for enabling mobility for the MN 11.
The second PDSN 17 sends a new L2TP message 43, Fast L2TP Set-Up CA 02359040 2001-09-27 ; 51 4 3457929 PATENT APPLICATION
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Request, to extend the PPP connection from the second PDSN I7 to the first PDSN 16. This message contains information for both setting up the L2TP tunnel 28 and for requesting information about the PPP connection 24 for the MN 11.
In response to the message above, the first PDSN 16 returns a Fast L2TP Set-Up Acknowledgement 44 containing the requested information. The second PDSN
17 then sends a message 45 to the MN I1, indicating that the original PPP
connection 24 (although, unbeknownst to the MN 11, it is now really called 24') is active, after which the handover is done.
Any communication data is now sent from the MN 1 I to the second PDSN
17, that tunnels the data via L2TP or any other tunnelling scheme to the first PDSN 16, which in turn tunnels the data to the IP network 22 via the IP
connection 25.
It should be understood that any tunnelling scheme, for example MiP
tunnelling, could be used between the two PDSNs 16-17, in which case the tunnel z5 and the corresponding messages are changed accordingly. It is also to be understood that the signalling is not limited to the above-mentioned messages;
but that any number or type of messages could be used to transfer the necessary information.
Figure 5 illustrates in Figures 5a-5c a second preferred embodiment of z o handover for Mobile IP. Figure 5a shows the pre-handover situation for a Mobile Node (MN) I1, a first and a second Radio Network (RN) 13-I4, a first and a second Packet Data Serving Node (PDSN) 16-17, and a Home Agent (HA) 20.
The MN 1 I and the PDSN 16 are connected via a PPP connection 24 (over the air interface IS and the R-P interface I8) while the PDSN 1.6 and the HA are CA 02359040 2001-09-27 ; 5 1 4 3457929 PATENT APPLICATION
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connected via a MIP connection 25.
As previously, during the handover, the second RN 14 is provided with the PDSN IP Address by the MN 11 in message 41, or by a node in the system, e.g.
the first RN 13 ox an MSC (not shown). To keep the PPP connection 24 during s the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN i4 then selects which PDSN 16-17 to connect to {as in the example, PDSN 17), in an accepted fashion. The second RN 14 also sends, included in the standard set-up messages 42, the PDSN IP Address it received 1o earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as it makes it possible to begin in parallel setting up a new R-P
connection (not shown) and, for the second PDSN 17, to obtain, from the first PDSN 16 through a signalling link 29 shown in Figure Sb, information about the PPP and MIP connections 24 and 25, respectively, the information being sent in 15 at least one message 46. The information could for example be exchanged via L2TP tunnel control messages (as above) or any other suitable signalling messages. Figure Sb shows the logical connection status at this point.
There are two different possibilities as to the downloading of information from the first PDSN 16 to the second PDSN 17 described hereinbefore. One a o possibility is to download relevant information about the connections as quickly as possible after the information is requested by the second PDSN 17 in order to enable the handover, while all other information in the first PDSN 16 pertaining to the MN 11 is downloaded later. Using this possibility, the object is to make the first PDSN 16 superfluous after which the second PDSN 17 is the sole PDSN 16-;514 3457929 PATENT APPLICATION
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17 dealing the MN 11, and the connection 29 between the two PDSNs I6-17 is terminated. A second possibility is to download the connection information as quickly as possible after the information is requested by the second PDSN 17, while other information related to the MN 11, such as for example information s about services the MN 11 accesses, remains with the frst PDSN 16. In this case, the connection 29 between the PDSNs 16-17 is kept.
The second PDSN 17 then either establishes a new MIP connection with the HA 20 or copies the MIP connection 25 (the new connection denoted by 25' in Figure Sc) between the first PDSN 16 and the HA 20, after which the first 1 o PDSN 1 b terminates its own MIP connection 25 with the HA 20. The second PDSN 17 then sends a message 45 to the MN 11, indicating that the original PPP
connection 24 is active, after which the handover is done. Figure 5c shows the network at this point.
Communication data is then sent between the MN 11 and the HA 20 via the second PDSN 17 that copied at least the PPP connection 2~ via the first PDSN
Ib, with which it keeps contact in case it has not downloaded all the relevant informarion about the MN 11, as described above. As the second PDSN 17 simply copied at least the PPP connection 24, there was no need to fully re-establish at least the PPP connection 24, which gives an efficient handover 2 o procedure.
Figure 6 illustrates in Figures 6a-6c a second preferred embodiment of handover for Simple IP. Figure 6a shows the pre-handover situation for a Mobile Node (MN) 11, a first and a second Radio Network (RN) 13-14, a first and a second Packet Data Serving Node (PDSN) 16-17, and an IP network 22. The MN
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11 and the PDSN 16 are connected via a PPP connection 24 (over the air interface 15 and the R-P interface 18) while the PDSN 16 is connected to the IP network via an IP connection 25.
As previously, during the handover, the second RN 14 is provided with the PDSN IP Address by the MN 11 in message 41, or by a node in the system, e.g.
the first RN 13 or an MSC (not shown). To keep the PPP connection 24 during the handover, the MN 11 acts internally to maintain the Link Control Protocol (LCP) link (not shown) over which the PPP connection 24 runs.
The second RN 14 then selects which PDSN 16-17 to connect to (as in the a. o example, PDSN 17), in an accepted fashion. The second RN 14 also sends, included in the standard set-up messages 42, the PDSN IP Address it received earlier to the second PDSN 17. This enables the reduction of delay in the overall handover process as it makes it possible to begin in parallel setting up a new R-P
connection (not shown) and, for the second PDSN 17, to obtain, from the first 15 PDSN 16 through a signalling link 29 shown in Figure 6b, information about the PPP connection 24, the information being sent in at least one message 46. The information could fox example be exchanged via L2TP tunnel control messages (as hereinbefore) or any other suitable signalling messages. Figure 6b shows the logical connection status at this point.
2 o There are two different possibilities as to the downloading of information from the first PDSN 16 to the second PDSN 17 described hereinbefore. One possibility is to download relevant information about the connections as quickly as possible after the information is requested by the second PDSN 17 in order to enable the handover, while all other information in the first PDSN 16 pertaining CA 02359040 2001-09-27 ; 5 1 4 3457929 PATENT APPLICATION
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to the MN 11 is downloaded later. Using this possibility, the object is to make the first PDSN 16 superfluous after which the second PDSN 17 is the sole PDSN 16-17 dealing the MN 11, and the connection 29 between the two PDSNs 16-17 is terminated. A second possibility is to download the connection information as quickly as possible after the information is requested by the second PDSN I7, while other information related to the MN 11, such as for example information about services the MN 11 accesses, remains with the first PDSN 16. In this case, the connection 29 between the PDSNs 16-17 is kept.
The second PDSN 17 then either preferably establishes a new IP
1 o connection with the 1P network 22 or copies the l.P connection 25 (the new connection denoted by 25' in Figure 6c) between the first PDSN 16 and the IP
network 22, after which the first PDSN 16 terminates its own IP connection 25 with the IP network 22. The second PDSN 17 then sends a message 45 to the MN
11, indicating that the original PPP connection 24 is active, after which the handover is done. Figure 6c shows the network at this point.
Communication data is then sent between the MN 1 l and the IP network 22 via the second PDSN I7 that copied at least the PPP connection 24 via the first PDSN 16, with which it keeps contact in case it has not downloaded all the relevant information about the MN 11, as described above. As the second PDSN
a o I7 simply copied at least the PPP connection 24, there was no need to fully re-establish at least the PPP connection 24, which gives an efficient handover procedure.
There are two different options of handling the case where the MN 11 hands over to yet another, third, PDSN (not shown). The first option is simply to CA 02359040 2001-09-27 :514 3457929 PATENT APPLICATION
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apply the hereinbefore mentioned handover method one more time, in which case there will be a series of tunnels or connections 28, 29 leading from the new PDSN
through the previous to the first.
The second, preferable option is to inform the third PDSN {not shown) s about the identity of the first PDSN 16. In the first embodiment, the third PDSN
contacts the second PDSN 17 as in the description in order to receive information and to copy the PPP connection 24. The third PDSN also receives the identity of the first PDSN 16, for example from the MN 11 or the second PDSN I7. Then, the third PDSN sets up a link to the first PDSN 16 and takes over the PPP
1o connection 24 to the MN 11, while the second PDSN 17 terminates its connections 24, 28 or 29.
In the second embodiment, the procedure depends on whether the first PDSN 16 still retains information about the MN 11 or not. In case the first PDSN
16 does not retain any information about the MN 11, then the further handover a5 procedure is straightforward following the description above. If, however, the first PDSN 16 still retains some responsibility for the MN 11, the procedure is as described above, with some additions. The third PDSN (not shown) receives the identity of the first PDSN 16, for example from the MN 11 or the second PDSN
17. Then it sets up a connection 28, 29 with the first PDSN 16, after which the a o second PDSN 17 can terminate its connection 28, 29 with the first PDSN 16.
It is also to be understood that there is no absolute necessity to change both RN 13-14 and PDSN 16-17 during the handover. It is perfectly conceivable that a RN 13-14 might want to change PDSN 16-I7 for the MN 11, but the handover m CA 02359040 2001-09-27 ; 51 4 3457929 PATENT APPLICATION
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would follow the same steps as detailed above, except that there is no need for the MN 11 to change RN 1.3-14.
As can be seen from the description above, thexe are provided efficient handover methods for Simple IP and Mobile IP, that in the case of Simple IP
enables handover, and in the case of Mobile IP makes the handover more efficient.
Although several preferred embodiments of the method and system of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.
Claims (40)
1. A handover method in a CDMA2000 network comprising a mobile node (MN) and at least a first and a second Packet Data Serving Node (PDSN), where the MN is connected to a first of the PDSNs via a first Point-to-Point Protocol (PPP) connection, the method comprising the steps of:
- choosing the second PDSN to hand the MN over to;
- obtaining by the second PDSN information about the first PPP
connection;
- establishing a second PPP connection from the MN to the second PDSN, using the information;
- establishing a connection from the second PDSN to the first PDSN;
- extending the PPP connection from the second PDSN to the first PDSN; and - informing the MN that the handover is complete.
- choosing the second PDSN to hand the MN over to;
- obtaining by the second PDSN information about the first PPP
connection;
- establishing a second PPP connection from the MN to the second PDSN, using the information;
- establishing a connection from the second PDSN to the first PDSN;
- extending the PPP connection from the second PDSN to the first PDSN; and - informing the MN that the handover is complete.
2. The handover method according to claim 1 further comprising, the step of terminating the first PPP connection between the MN and the first PDSN.
3. The handover method according to claim 1, wherein the network further comprises at least a first and a second Radio Network (RN) and wherein the MN is connected to the first RN, the method further comprising, prior to the step of choosing the second PDSN to hand over to, the step of handing over from a first RN to a second RN.
4. The handover method according to claim 3, wherein the step of obtaining by the second PDSN information about the first PPP
connection comprises:
- obtaining, by the second RN, an IP address associated with the MN; and - forwarding, by the second RN, the IP address to the second PDSN.
connection comprises:
- obtaining, by the second RN, an IP address associated with the MN; and - forwarding, by the second RN, the IP address to the second PDSN.
5. The handover method according to claim 4, wherein the step of obtaining by the second RN, an IP address associated with the MN, comprises sending the IP address from the MN to the second RN.
6. The handover method according to claim 4, wherein the step of obtaining by the second RN, an IP address associated with the MN, comprises sending the IP address from the first RN to the second RN.
7. The handover method according to claim 4, wherein the second RN
sends at least one set-up message to the second PDSN in order to set up a connection with the second PDSN and wherein the IP address is forwarded from the second RN to the second PDSN in at least one of the set-up messages transmitted.
sends at least one set-up message to the second PDSN in order to set up a connection with the second PDSN and wherein the IP address is forwarded from the second RN to the second PDSN in at least one of the set-up messages transmitted.
8. The handover method according to claim 3, wherein the step of choosing the second PDSN to hand over to is performed by a RN.
9. The handover method according to claim 1, wherein the step of establishing a connection from the second PDSN to the first PDSN
comprises setting up a tunnel between the PDSNs.
comprises setting up a tunnel between the PDSNs.
10. The handover method according to claim 9, wherein the tunnel is a Layer 2 Tunnelling Protocol tunnel.
11. The handover method according to claim 1, further comprising the step of the MN acting internally to maintain the first PPP connection until the MN is informed that the handover is complete.
12. A handover method in a CDMA2000 network comprising a mobile node (MN), at least a first and a second Packet Data Serving Node (PDSN) and a IP network, where the MN is connected to a first of the PDSNs via a first Point-to-Point Protocol (PPP) connection and the first PDSN is connected to the IP network, the method comprising the steps of:
- choosing the second PDSN to hand the MN over to;
- obtaining by the second PDSN information about the first PPP
connection;
- obtaining by the second PDSN information about the first connection from the first PDSN to the IP network;
- establishing a second PPP connection from the MN to the second PDSN, using the information;
- establishing a connection from the second PDSN to the IP
network; and - informing the MN that the handover is complete.
- choosing the second PDSN to hand the MN over to;
- obtaining by the second PDSN information about the first PPP
connection;
- obtaining by the second PDSN information about the first connection from the first PDSN to the IP network;
- establishing a second PPP connection from the MN to the second PDSN, using the information;
- establishing a connection from the second PDSN to the IP
network; and - informing the MN that the handover is complete.
13. The handover method according to claim. 12 further comprising the step of terminating the PPP connection between the MN and the first PDSN.
14. The handover method according to claim 12, wherein the network further comprises at least a first and a second Radio Network (RN), the method further comprising, prior to the step of choosing the second PDSN to hand over to, the step of handing over the MN from a first RN to a second RN.
15. The handover method according to claim 14, wherein the step of obtaining by the second PDSN information about the PPP
connection comprises:
- obtaining, by the second RN, an IP address associated with the MN; and - forwarding, by the second RN, the IP address to the second PDSN.
connection comprises:
- obtaining, by the second RN, an IP address associated with the MN; and - forwarding, by the second RN, the IP address to the second PDSN.
16. The handover method according to claim 15, wherein the step of obtaining, by the second RN, an IP address associated with the MN, comprises sending the IP address from the MN to the second RN.
17. The handover method according to claim 15, wherein the step of obtaining, by the second RN, an IP address associated with the MN, comprises sending the IP address from the fiarst RN to the second RN.
18. The handover method according to claim 15, wherein the second RN
sends at least one set-up message to the second PDSN in order to set up a connection with the second PDSN and where the IP address is forwarded from the second RN to the second PDSN in at least one of the set-up messages transmitted.
sends at least one set-up message to the second PDSN in order to set up a connection with the second PDSN and where the IP address is forwarded from the second RN to the second PDSN in at least one of the set-up messages transmitted.
19. The handover method according to claim 14, wherein the step of choosing the second PDSN to hand over to is performed by a RN.
20. The handover method according to claim 12, further comprising the step of the MN acting internally to maintain the PPP connection until it is informed that the handover is complete.
21. The handover method according to claim 12, where the step of obtaining by the second PDSN information about the connection from the first PDSN to the IP network comprises the second PDSN
contacting the first PDSN for requesting the information and the first PDSN responding with the information.
contacting the first PDSN for requesting the information and the first PDSN responding with the information.
22. A system for mobile node (MN) handover in a CDMA2000 network, the system comprising:
- at least a first and a second Packet Data Serving Node (PDSNs), wherein the MN is connected to the first PDSN through a Point-to-Point Protocol (PPP) connection; and - at least one Radio Network (RN) being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which the PPP connection is established, the RN
choosing a second PDSN to hand over to;
wherein the second PDSN
obtains information about the first PPP connection;
uses the information to establish a second PPP
connection between the MN to the second PDSN;
establishes a connection from the second PDSN to the first PDSN;
extends the PPP connection over the connection with the first PDSN, whereby the PPP connection runs from the MN to the first PDSN; and informs the MN that the handover is complete.
- at least a first and a second Packet Data Serving Node (PDSNs), wherein the MN is connected to the first PDSN through a Point-to-Point Protocol (PPP) connection; and - at least one Radio Network (RN) being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which the PPP connection is established, the RN
choosing a second PDSN to hand over to;
wherein the second PDSN
obtains information about the first PPP connection;
uses the information to establish a second PPP
connection between the MN to the second PDSN;
establishes a connection from the second PDSN to the first PDSN;
extends the PPP connection over the connection with the first PDSN, whereby the PPP connection runs from the MN to the first PDSN; and informs the MN that the handover is complete.
23. The system according to claim 22 where the first PDSN terminates the PPP connection between itself and the MN.
24. The system according to claim 22 comprising a second radio network (RN) that the MN is handed over to, and that in turn hands over to a second PDSN, wherein the second RN obtains an IP
address associated with the MN and forwards the IP address to the second PDSN.
address associated with the MN and forwards the IP address to the second PDSN.
25. The system according to claim 24, wherein the second RN obtains the IP address associated with the MN from the MN itself
26. The system according to claim 24, wherein the second RN obtains the IP address associated with the MN from the first RN.
27. The system according to claim 22, wherein the connection from the second PDSN to the first PDSN is a tunnel.
28. The system according to claim 27, wherein the tunnel is a Layer 2 Tunnelling Protocol tunnel.
29. A system for mobile node (MN) handover in a CDMA2000 network, the system comprising:
- at least a first and a second Packet Data Serving Nodes (PDSN), where the MN is connected to the first PDSN through a first Point-to-Point Protocol (PPP) connection and where the first PDSN has a connection with an IP network; and - at least one Radio Network (RN), being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which protocols the PPP connection is established, the RN choosing a second PDSN to hand over to;
wherein the second PDSN
obtains information about the first PPP connection and the connection to the IP network;
uses the information about the first PPP connection to establish a second PPP connection between the MN and the second PDSN and a connection between the second PDSN and the IP network; and informs the MN that the handover is complete.
- at least a first and a second Packet Data Serving Nodes (PDSN), where the MN is connected to the first PDSN through a first Point-to-Point Protocol (PPP) connection and where the first PDSN has a connection with an IP network; and - at least one Radio Network (RN), being an intermediate node between the MN and the PDSN, connected to the MN through an air interface and to the PDSN through a Radio Packet (R-P) interface, over which protocols the PPP connection is established, the RN choosing a second PDSN to hand over to;
wherein the second PDSN
obtains information about the first PPP connection and the connection to the IP network;
uses the information about the first PPP connection to establish a second PPP connection between the MN and the second PDSN and a connection between the second PDSN and the IP network; and informs the MN that the handover is complete.
30. The system according to claim 29 wherein the first PDSN terminates the PPP connection between itself and the MN.
31. The system according to claim 29 wherein the first PDSN terminates its connection with the IP network.
32. The system according to claim 29, the system comprising a second radio network (RN) that the MN is handed over to and that in turn hands over to a second PDSN, wherein the second RN obtains an 1P
address associated with the MN and forwards the TP address to the second PDSN.
address associated with the MN and forwards the TP address to the second PDSN.
33. The system according to claim 32, wherein the second RN obtains the IP address associated with the MN from the MN.
34. The system according to claim 32, wherein the second RN obtains the IP address associated with the MN from the first RN.
35. The system according to claim 29, wherein the second PDSN obtains information about the connection from the first PDSN to the IP
network and the PPP connection by asking the first PDSN for the information and the first PDSN responds with the information.
network and the PPP connection by asking the first PDSN for the information and the first PDSN responds with the information.
36. A Packet Data Serving Node (PDSN) for mobile node (MN) handover in a CDMA2000 network, where the MN is handed over to the PDSN, where the PDSN:
- obtains information about a first PPP connection that connects the MN to a previous PDSN;
- uses the information to establish a second PPP connection to the MN;
- establishes a connection to the previous PDSN;
- extends the second PPP connection whereby the second PPP
connection runs from the MN to the previous PDSN; and - informs the MN that the handover is complete.
- obtains information about a first PPP connection that connects the MN to a previous PDSN;
- uses the information to establish a second PPP connection to the MN;
- establishes a connection to the previous PDSN;
- extends the second PPP connection whereby the second PPP
connection runs from the MN to the previous PDSN; and - informs the MN that the handover is complete.
37. The Packet Data Serving Node (PDSN) according to claim 36, wherein the connection to the previous PDSN is a tunnel.
38. The Packet Data Serving Node (PDSN) according to claim 37, wherein the tunnel is a Layer 2 Tunnelling Protocol tunnel.
39. A Packet Data Serving Node (PDSN) for mobile node (MN) handover in a CDMA2000 network, wherein the MN is handed over to the PDSN from a second PDSN that is connected to an IP
network, wherein the PDSN:
- obtains information about a first PPP connection that connects the MN to a previous PDSN;
- uses the information to establish a second PPP connection to the MN;
- establishes a connection to the second PDSN;
- obtains information about the connection between the second PDSN and the IP network;
- uses the information to establish a second connection with the IP
network; and informs the MN that the handover is complete.
network, wherein the PDSN:
- obtains information about a first PPP connection that connects the MN to a previous PDSN;
- uses the information to establish a second PPP connection to the MN;
- establishes a connection to the second PDSN;
- obtains information about the connection between the second PDSN and the IP network;
- uses the information to establish a second connection with the IP
network; and informs the MN that the handover is complete.
40. The PDSN according to claim 39, wherein the PDSN obtains information about the connection from the second PDSN to the IP
network and the first PPP connection by requesting from the second PDSN the information.
network and the first PPP connection by requesting from the second PDSN the information.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US67039200A | 2000-09-28 | 2000-09-28 | |
| US09/670,392 | 2000-09-28 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2359040A1 CA2359040A1 (en) | 2002-03-28 |
| CA2359040C true CA2359040C (en) | 2004-11-16 |
Family
ID=24690224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002359040A Expired - Fee Related CA2359040C (en) | 2000-09-28 | 2001-09-27 | Methods and system for inter packet data serving node (pdsn) handover and mobility in a cdma2000 network |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN1348275A (en) |
| CA (1) | CA2359040C (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6909899B2 (en) * | 2002-03-11 | 2005-06-21 | Qualcomm, Incoporated | Method and apparatus for handoff in a communication system supporting multiple service instances |
| US7835324B2 (en) | 2002-04-11 | 2010-11-16 | Nortel Networks Limited | Resource optimization in a wireless IP network |
| US7085251B2 (en) | 2002-11-04 | 2006-08-01 | Qualcom Incorporated | Method and apparatus for handoff of a wireless packet data services connection |
| WO2005010708A2 (en) | 2003-07-17 | 2005-02-03 | Starent Networks Corp. | Methods and systems for providing improved handoffs in a wireless communication system |
| US8619701B2 (en) * | 2004-05-03 | 2013-12-31 | Core Wireless Licensing S.A.R.L. | Method of facilitating handoff for CDMA networks using IP protocols |
| US7551585B2 (en) * | 2004-12-03 | 2009-06-23 | Telefonaktiebolaget Lm Ericsson (Publ) | Seamless handoff for multimedia services |
| CN101128022B (en) * | 2006-08-18 | 2011-02-02 | 华为技术有限公司 | Terminal switching method and device and acquisition method and device for source access gateway address |
| CN101345696B (en) * | 2007-07-12 | 2011-03-16 | 中国科学院声学研究所 | Fast switching method for proxy mobile IP |
| US8811281B2 (en) | 2011-04-01 | 2014-08-19 | Cisco Technology, Inc. | Soft retention for call admission control in communication networks |
| WO2012152128A1 (en) * | 2011-05-10 | 2012-11-15 | 中兴通讯股份有限公司 | Handover method and system |
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2001
- 2001-09-27 CA CA002359040A patent/CA2359040C/en not_active Expired - Fee Related
- 2001-09-28 CN CN01137958A patent/CN1348275A/en active Pending
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| CN1348275A (en) | 2002-05-08 |
| CA2359040A1 (en) | 2002-03-28 |
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