Anchoring Services Of A Mobile Station Attached To A First
Service Domain At A Home Agent In A Second Service Domain
Background
[0001] Various wireless access technologies have been proposed or implemented to
enable mobile stations to perform communications with other mobile stations or with wired
terminals coupled to wired networks. Examples of wireless access technologies include
GSM (Global System for Mobile communications) and UMTS (Universal Mobile
Telecommunications System) technologies, defined by the Third Generation Partnership
Project (3GPP); and CDMA 2000 (Code Division Multiple Access 2000) technologies,
defined by 3GPP2.
[0002] As part of the continuing evolution of wireless access technologies to improve
spectral efficiency, to improve services, to lower costs, and so forth, new standards have been
proposed. One such new standard is the Long Term Evolution (LTE) standard from 3GPP,
which seeks to enhance the UMTS wireless network.
[0003] Dual-mode mobile stations can perform access using different types of wireless
access networks, such as a legacy HRPD (High Rate Packet Data) wireless access network
(as defined by CDMA 2000) or a E-UTRAN (Evolved UMTS Terrestrial Radio Access
Network, as defined by 3GPP). The E-UTRAN wireless access network allows for access of
4G (fourth generation) wireless services, such as those provided by LTE.
[0004] As service operators evolve from legacy wireless access networks to 4G
networks, such service operators typically have to support subscriber access at both types of
networks. When a mobile station (such as a dual mode mobile station) attaches to an E-
UTRAN wireless access network, for example, services provided in the legacy network may
no longer be available to the mobile station.
Summary
[0005] In general, a technique or mechanism is provided to allow anchoring of the
services in a home network of the mobile station even when the mobile station is attached to
a wireless access network of a different service domain.
[0006] Other or alternative features will become apparent from the following
description, from the drawings, and from the claims.
Brief Description Of The Drawings
[0007] Figs. 1-3 illustrate portions of different networks that incorporate some preferred
embodiments of the invention; and
[0008] Fig. 4 is a block diagram of components in a node of a first service domain and
a home agent node in a second service domain, according to an example preferred
embodiment.
Detailed Description
[0009] In the following description, numerous details are set forth to provide an
understanding of some embodiments. However, it will be understood by those skilled in the
art that some embodiments may be practiced without these details and that numerous
variations or modifications from the described embodiments may be possible.
[0010] Various services can be provided to a mobile station by a home service domain
of the mobile station. Examples of such services include an accounting/billing service; a
gaming service; a push-to-talk service; an instant conferencing or messaging service; a
calendaring service; a location-based service (e.g., find the nearest store or other location); a
presence service (e.g., service that follows the subscriber's movements); broadcast and
multicasting services (e.g., relating to Internet TV); and so forth.
[0011] Thus, when the mobile station is attached to a wireless access network of the
mobile station's home service domain, such services can be provided to the mobile station.
In one example embodiment, the home service domain of the mobile station includes an
HRPD (High Rate Packet Data) wireless access network, as defined by 3GPP2, to support
wireless access by the mobile station. The HRPD wireless access network is considered to be
a legacy wireless access network. The home service domain in this example is considered a
legacy service domain that supports services according to an older standard, such as the
3GPP2 CDMA 2000 standard. A "service domain" refers to an arrangement of network
nodes associated with one or more service operators to provide wireless access and other
services to a mobile station.
[0012] New wireless technologies are being developed, with one such new technology
being the Long Term Evolution (LTE) technology from 3GPP. The LTE network uses E-
UTRAN as the wireless access technology for the mobile station to access the LTE network.
In this example, LTE defines a second service domain that is of a different type than the
home (or legacy) service domain.
[0013] Although reference is made to the HRPD and LTE standards above, it is noted
that in alternative preferred embodiments other types of service domains can be employed.
[0014] An issue associated with a mobile station that is attached to the E-UTRAN
wireless access network is that the mobile station tends to follow LTE procedures and
protocols, which may cause the mobile station to be anchored at a node in the LTE service
domain. However, anchoring the mobile station in the LTE service domain means that the
mobile station may no longer be able to access various services provided by the home service
domain.
[0015] In accordance with some embodiments, to address the foregoing issue, a
mechanism is provided to anchor a session of the mobile station at a node in the home service
domain of the mobile station, even if the mobile station is attached to the E-UTRAN wireless
access network (in a different service domain). By anchoring the mobile station at the node
in the home service domain, services of the home service domain can be made available to
the mobile station even though the mobile station is located in a different service domain.
[0016] In some embodiments, the node of the home service domain at which the
session of the mobile station is anchored is a home agent as defined by either Proxy Mobile
IPv4 (Internet Protocol version 4) or Proxy Mobile IPv6 (Internet Protocol version 6). Proxy
Mobile IPv6 is defined by Request for Comments (RFC) 5213, entitled "Proxy Mobile IPv6,"
dated August 2008. Proxy Mobile IPv4 is defined by K. Leung et al., Internet-Draft, entitled
"WiMAX Forum/3GPP2 Proxy Mobile IPv4," draft-leung-mip4-proxy-mode-10.txt, dated
November 2008.
[0017] A home agent, as defined by Mobile IPv4 or IPv6, is a router on a mobile
station's home network with which the mobile station has registered its current care-of
address. In Proxy Mobile IPv6, the functionality of the home agent is provided in a local
mobility anchor (LMA), which provides the functionalities of the home agent, as well as
additional capabilities for supporting the Proxy Mobile IPv6 protocol. Thus, as used here,
"home agent" refers to either a Mobile IP home agent or a Proxy Mobile IPv6 local mobility
anchor.
[0018] Various different embodiments for anchoring the services of the mobile station
at the home agent of the mobile station while the mobile station is attached to a different
service domain are provided. Fig. 1 illustrates a first solution according to an embodiment.
In Fig. 1, two service domains are illustrated, including an LTE service domain 100 and a
legacy service domain 102. In the example of Fig. 1, the legacy service domain 102 uses
HRPD wireless access technology with a core network defined by 3GPP2.
[0019] In the legacy service domain 102, a wireless access network 104 includes an
HRPD base transceiver station (BTS) 106, and an access network (AN) node 108 that is
attached to an AAA (authentication, authorization, and accounting) server 110 for performing
authentication, authorization, and accounting tasks when a mobile station attaches to the
wireless access network 104.
[0020] The wireless access network 104 is connected to a PDSN (packet data serving
node) 112 that provides access to an external packet data network such as the Internet, an
intranet, or an application server. The PDSN 112 is a component of the CDMA 2000
network, and acts as a connection point between a wireless access network and the external
packet data network.
[0021] The legacy service domain 102 also includes a home agent (HA) 116, which
enables the creation and maintenance of a binding between a mobile station's home address
and its care-of address (the address used by the mobile station when it is attached to a visited
network). The home agent manages the services provided to the mobile station, including
3GPP2 services provided by a 3GPP2 service network 118. The 3GPP2 service network
includes a service provider AAA server 120 to perform authentication, authorization, and
accounting services when services of the 3GPP2 service network 118 are accessed by a
mobile station.
[0022] The LTE service domain 100 includes an E-UTRAN wireless access network
120 to allow for wireless access by mobile stations, including a mobile station 130. In
addition, the LTE service domain 100 includes a serving gateway (SGW) that routes and
forwards user data packets to a PDN (packet data network) gateway 126. The PDN gateway
126 provides connectivity from the mobile station to an external packet data network by
being the point of exit and entry of data traffic for the mobile station. The serving gateway is
the anchor point for intra-3GPP mobility, as the mobile station 130 moves to different access
points in the E-UTRAN wireless access network 120 that causes different SGWs to be
selected.
[0023] The terms "serving gateway" and "packet data network gateway" can also be
applied to other types of service domains (other than the LTE service domain). More
generally, a packet data network gateway can refer to any point that establishes connectivity
between a service domain and an external packet data network. A serving gateway can refer
to any node that manages mobility of a mobile station within a service domain.
[0024] Another entity in the LTE service domain 100 is a mobility management entity
(MME) 122, which is a control node that provides various control services for a mobile
station. Examples of such services include tracking the mobile station, providing a paging
procedure for the mobile station, and so forth. The MME 122 is also involved in bearer
activation and deactivation process, and is responsible for choosing the SGW for the mobile
station at the time that the mobile station initially attaches to the E-UTRAN wireless access
network 120.
[0025] In accordance with the embodiment shown in Fig. 1, a link 128 is provided
between the SGW 124 and the home agent 116 to allow the mobile station 130 attached to the
E-UTRAN wireless access network 120 to be anchored by the home agent 116 (rather than be
anchored at a node in the LTE domain 100). In this manner, the 3GPP2 services provided by
network 118 in the legacy service domain 102 can continue to be available to the mobile
station 130 that is attached to the E-UTRAN wireless access network 120.
[0026] There are two contexts in which the mobile station 130 can be anchored by the
home agent 116 of the legacy service domain 102. In a first context, the mobile station 130 is
a dual mode mobile station that is able to attach either to the HRPD wireless access network
104 of the legacy service domain 102, or to the E-UTRAN wireless access network 120 of
the LTE service domain 100. In a second context, the mobile station 130 can be an LTE-only
mobile station that is able to attach only to the E-UTRAN wireless access network 120.
[0027] When the mobile station 130 initially attaches to the E-UTRAN wireless access
network 120, the mobile station 130 performs access authentication based on E-UTRAN
access procedures. As part of this access authentication process, the SGW 124 receives user
information, including the home agent IP address (the IP address of the home agent 116)
associated with the mobile station 130. Other parameters of the user information received by
the SGW 124 can include a user NAI (network access identifier), supported APNs (access
point names, which are names used to identify bearer services), a user profile, mobility
security association parameters, and so forth.
[0028] Upon receipt of the user information, the SGW 124 sends (at 150) a registration
request, which can be a proxy RRQ (registration request) as defined by Proxy Mobile IPv4,
on behalf of the mobile station 130 to the home agent 116 over the link 128 between the
SGW 124 and home agent 116. Note that the SGW 124 has the IP address of the home agent
116 since the SGW 124 has received the IP address of the home agent as part of the mobile
station access authentication process. Upon receipt of the proxy RRQ from the SGW 124
over the link 128 (which can be a link that supports proxy mobile IPv4), the home agent 116
registers the mobile station's session. In addition, the home agent 116 allocates (at 152) an IP
address for the session that the mobile station can use.
[0029] The home agent 116 then sends (at 154) a registration response message (e.g.,
proxy RRP) back to the SGW 124 over the link 128. The proxy RRP message contains the
allocated IP address for the mobile station. In response to the proxy RRP message, the SGW
124 follows the E-UTRAN access procedures to deliver (at 156) the IP address to the mobile
station 130 through the E-UTRAN wireless access network 120.
[0030] It is noted that from the perspective of the home agent 116, the SGW 124
appears to be a PDSN similar to PDSN 112 in the legacy service domain 102.
[0031 ] Whenever the mobile station moves across E-UTRAN wireless access network
120 (e.g., moves between different base stations), it is possible that a transfer from a source
SGW to a target SGW would have to be performed. For an inter-SGW transfer, the system
according to some embodiments ensures that the target SGW will receive the IP address of
the mobile station's home agent (116), such that the target SGW can issue a proxy RRQ to
the home agent 116 to cause the home agent 116 to assign the same IP address to the mobile
station to maintain mobility and access to the 3GPP2 services infrastructure.
[0032] Fig. 2 illustrates an arrangement that supports an alternative embodiment of the
invention. In this second embodiment, instead of establishing a link 128 (Fig. 1) between the
SGW 124 and the home agent 116, a link 202 is established between the PDN gateway 126
and the home agent 116. The nodes illustrated in Fig. 2 are the same nodes as illustrated in
Fig. 1. The link 202 supports Proxy Mobile IPv4 and IP-in-IP tunneling between the PDN
gateway 126 and the home agent 116. IP-in-IP tunneling refers to encapsulating one IP
packet in the payload of another IP packet.
[0033] In the second solution that employs the arrangement of Fig. 2, the PDN gateway
126 supports proxy Mobile IPv4 mobile access gateway (MAG) or proxy mobility agent
(PMA) functionality. PMA manages the mobility related signaling for a mobile station that is
attached to the MAG. The MAG performs mobility management on behalf of the mobile
station. The MAG also tracks the mobile station's movements so that handover between the
MAG and another MAG can be performed when the mobile station crosses between coverage
areas of the respective MAGs.
[0034] After the mobile station performs access authentication based on E-UTRAN
access procedures, the SGW 124 receives the user information including the IP address of the
PDN gateway 126 and other parameters as discussed above in connection with Fig. 1. Upon
receiving such information, the SGW 124 follows 3GPP procedures to establish an IP session
for the mobile station at the PDN gateway 126. This can be accomplished by using a binding
procedure (210) as defined by Proxy Mobile IPv6, such as by sending a proxy binding update
(PBU) message that requests an IP address for the mobile station.
[0035] When the PDN gateway 126 receives the proxy binding update message, the
PDN gateway 126 either by using out-of-band signaling or static configuration, finds the IP
address of the home agent that is supposed to anchor the IP session for the mobile station.
Out-of-band signaling can be performed by accessing an AAA server to select the home
agent. Alternatively, the PDN gateway 126 may be provided with multiple home agents from
which the PDN gateway 126 can make a selection (for load balancing purposes). As yet
another alternative, static configuration is provided, where the PDN gateway 126 has to use a
particular home agent.
[0036] Upon obtaining the IP address of the home agent 116, the PDN gateway 126
sends (at 212) a proxy RRQ message to the home agent 116 to allocate an IP address to the
mobile station and to create a binding for the user session to a proxy care-of-address (CoA)
that is terminated at the PDN gateway 126.
[0037] When the home agent 116 receives the proxy RRQ message, the home agent
116 validates the proxy RRQ message and if successful, the home agent 116 will allocate (at
214) an IP address for the session that is returned (at 216) to the PDN gateway 126 in a proxy
RRP message. The home agent 116 also creates a binding for the user, its home address, and
the proxy care-of-address that belongs to the PDN gateway 126.
[0038] When the PDN gateway 126 receives the proxy RRP message from the home
agent 116 with the IP address of the mobile station included, the PDN gateway 126 sends a
proxy binding acknowledgement (PBA) to the SGW 124 (as part of the binding procedure
210) with the assigned home IP address, along with other parameters such as the IPv6 home
network prefix (HNP). The HNP is assigned to an interface of a mobile station to the Proxy
Mobile IP domain, and the HNP can be used to derive an address of the interface.
[0039] The PDN gateway 126 updates a mobile station's current BCE (binding cache
entry) with the home agent IP address. It is possible to create a separate binding that is linked
to the mobile station's proxy BCE.
[0040] When the SGW 124 receives the proxy binding acknowledgment message from
the PDN gateway 126, the SGW 124 delivers (at 218) the IP address and possibly the home
network prefix to the mobile station 130 following E-UTRAN access procedures.
[0041] It is noted that from the perspective of the home agent 116, the PDN gateway
126 appears to be a PDSN similar to PDSN 112 in the legacy service domain 102.
[0042] Whenever the mobile station moves across the E-UTRAN wireless access
network 120 that causes an inter-SGW transfer, the system ensures that the target SGW will
receive the IP address of the current PDN gateway 126 that maintains a binding of the mobile
station 130 to its current home agent. The target SGW will initiate the procedure discussed
above, which causes the home agent 116 to assign the same IP address to the mobile station
130 to maintain IP mobility and connectivity using the same IP address.
[0043] If the mobile station 130 moves to the HRPD wireless access network 104 from
the E-UTRAN wireless access network 120, the system will provide the PDSN 112 with the
address of the current home agent 116 that maintains and anchors the IP session of the mobile
station 130. When the PDSN 112 subsequently sends a proxy RRQ to the home agent 116,
the home agent 116 updates the mobile station binding with the new proxy care-of-address to
point to the PDSN 112 instead of the PDN gateway 126.
[0044] In accordance with another preferred embodiment, as illustrated in Fig. 3, a
GRE (Generic Routing Encapsulation) tunnel is employed over a link 302 between the PDN
gateway 126 and the home agent 116. GRE is a tunneling protocol that can encapsulate
various network layer protocol packet types inside IP tunnels to create virtual point-to-point
links. GRE is described in RFC 2784, entitled "Generic Routing Encapsulation (GRE),"
dated March 2000, as updated by RFC 2890, entitled "Key and Sequence Number Extensions
to GRE," dated September 2000.
[0045] In some implementations, DHCP (Dynamic Host Configuration Protocol)
functionality is supported by the PDN gateway 126 and home agent 116 to support the
solution according to this embodiment. DHCP is a network application protocol used by
devices (referred to as DHCP clients) to obtain configuration information regarding the
DHCP client from a DHCP server. DHCP for IPv4 networks is described in RFC 2131,
entitled "Dynamic Host Configuration Protocol," dated March 1997. DHCP for IPv6
networks is described in RFC 3315, entitled "Dynamic Host Configuration Protocol for IPv6
(DHCPv6)," dated July 2003.
[0046] The PDN gateway 126 supports DHCP client functionality, while the home
agent 116 supports DHCP relay functionality or DHCP server functionality. Since the DHCP
client and server functionality between the PDN gateway 126 and the home agent 116 are not
visible to the outside world, vendor-specific information can be communicated between the
PDN gateway 126 and the home agent 116 using the DHCP protocol, such as GRE keys.
[0047] As with the embodiments associated with Figs. 1 and 2, due to access
authentication by the mobile station based on E-UTRAN access procedures, the SGW 124
receives user information, including the IP address of the PDN gateway 126, along with other
parameters such as user NAI, supported APNs, the user profile, and so forth. When the SGW
124 receives such information, including the IP address of the PDN gateway 126, the SGW
follows 3GPP procedures to establish an IP session for the mobile station at the PDN gateway
126. For example, this can be accomplished by using a binding procedure (310) that includes
sending a proxy binding update message (according to Proxy Mobile IPv6) to the PDN
gateway 126 to request an IP address (and possibly an IPv6 home network prefix).
[0048] Upon receiving the proxy binding update message from the SGW 124, the PDN
gateway 126 using out-of-band signaling or static configuration is able to find the IP address
of the home agent 116 that is supposed to anchor the IP session of the mobile station. The
PDN gateway 126 identifies the static GRE tunnel over the link 302 that is used to
communicate with the home agent 116. If no GRE tunnel exists, the PDN gateway 126 will
initiate establishment of the GRE tunnel.
[0049] Next, the PDN gateway 126 sends (at 312) a DHCP request to the home agent
116 on the GRE tunnel. The DHCP request includes the user identity and an IP address
allocation request. Optionally, the DHCP request may also include a request for a GRE key
in case IP private address overlapping is supported.
[0050] When the home agent 116 receives the DHCP request, the home agent either
allocates (at 314) the IP address locally (as part of DHCP server functionality) or uses DHCP
relay functionality to obtain the information from another DHCP server to allocate the IP
address for the mobile station.
[0051 ] When the IP address of the mobile station is allocated, the home agent 116
maintains a binding of the user NAI and the mobile station's home IP address, and the GRE
tunnel interface (the PDN gateway 126 that sent the DHCP request) that this session/IP
address belongs to.
[0052] The home agent 116 then sends (at 316) a DHCP response that is responsive to
the DHCP request sent at 312. When the PDN gateway 126 receives the DHCP response, the
PDN gateway 126 updates the mobile station's BCE with the newly allocated IP address, and
the home agent IP address is updated with the current GRE tunnel interface.
[0053] In response to the proxy binding update message from the SGW 124, the PDN
gateway 126 sends a proxy binding acknowledgment message (part of the binding procedure
310) to the SGW 124 with the assigned home IP address and other parameters (including
possibly the IPv6 home network prefix). Upon receiving the proxy binding acknowledgment
message from the PDN gateway 126, the SGW 124 delivers (at 318) the allocated IP address
(and possibly the home network prefix) to the mobile station, using E-UTRAN access
procedures.
[0054] In case the mobile station moves across cells in the E-UTRAN wireless access
network 120 such that an inter-SGW transfer occurs, the target SGW will receive the current
mobile station's PDN gateway IP address to maintain a binding of the mobile station with its
home agent. The home agent will assign the same IP address to the same mobile station to
maintain IP mobility and connectivity using the same IP address.
[0055] If the mobile station moves to the HRPD access network 104, the system will
provide the PDSN 112 with the current home agent that maintains and anchors the mobile
station's IP session. When the PDSN 112 sends a proxy RRQ message to the home agent
116, the home agent 116 validates the list of mobile station bindings including those
established over the GRE tunnel with the PDN gateway 126 using the DHCP protocol. If the
same user NAI is already assigned to the IP address, the home agent 116 updates the mobile
station binding with the new proxy care-of-address to point to the PDSN 112 instead of the
PDN gateway 126.
[0056] Fig. 4 is a block diagram of nodes that are part of the networks depicted in Figs.
1-3. A first service domain node 400 can be a node in the LTE service domain 100, and the
home agent node 402 is a node that contains the home agent 116 of Figs. 1-3. A "node"
refers to any computing/processing assembly. For example, the first service domain node
400 can be either the SGW 124 or PDN gateway 126 of Figs. 1-3.
[0057] In the example of Fig. 4, the first service domain node 400 includes software
404 executable on a processor 406. The software 404 includes various software modules that
perform tasks of the SGW 124 and/or PDN gateway 126 discussed above. The processor is
connected to a storage media 410, and an interface 408 that allows the first service domain
node 400 to communicate with the home agent node 402.
[0058] The home agent node 402 includes software 414 executable on a processor 416
to perform various tasks of the home agent 116 discussed above. The processor 416 is
connected to a storage media 420 and an interface 418 to allow the home agent node 402 to
communicate with the first service domain node 400.
[0059] Instructions of the software 404 and 414 can be loaded from respective storage
media 410 and 420 for execution on the processors 406 and 416, respectively. A processor
includes microprocessors, microcontrollers, processor modules or subsystems (including one
or more microprocessors or microcontrollers), or other control or computing devices. A
"processor" can refer to a single component or to plural components (e.g., one CPU or
multiple CPUs).
[0060] Data and instructions (of the software) are stored in respective storage devices,
which are implemented as one or more computer-readable or computer-usable storage media.
The storage media include different forms of memory including semiconductor memory
devices such as dynamic or static random access memories (DRAMs or SRAMs), erasable
and programmable read-only memories (EPROMs), electrically erasable and programmable
read-only memories (EEPROMs) and flash memories; magnetic disks such as fixed, floppy
and removable disks; other magnetic media including tape; and optical media such as
compact disks (CDs) or digital video disks (DVDs).
[0061 ] In the foregoing description, numerous details are set forth to provide an
understanding of the present invention. However, it will be understood by those skilled in the
art that the present invention may be practiced without these details. While the invention has
been disclosed with respect to a limited number of embodiments, those skilled in the art will
appreciate numerous modifications and variations therefrom. It is intended that the appended
claims cover such modifications and variations as fall within the true spirit and scope of the
invention.
What is claimed is:
1. A method comprising:
receiving, at a first node, information associated with a mobile station to allow for
establishment of a session for the mobile station that is attached to a first wireless access
network in a first service domain;
in response to the received information, sending, by the first node, messaging to a
home agent in a second service domain that is of a different type than the first service
domain; and
receiving, by the first node from the home agent, an Internet Protocol (IP) address
allocated to the mobile station in the second service domain, wherein the IP address is
allocated in response to the messaging, and wherein services provided to the mobile station
are anchored in the second service domain.
2. The method of claim 1, wherein sending messaging to the home agent by the first
node comprises sending messaging to the home agent by a packet data network (PDN)
gateway.
3. The method of claim 2, wherein sending the messaging by the PDN gateway
comprises sending DHCP (Dynamic Host Configuration Protocol) messaging.
4. The method of claim 2, wherein sending the messaging by the PDN gateway
comprises sending the messaging through a GRE (Generic Routing Encapsulation) tunnel.
5. The method of claim 1, wherein sending the messaging to the home agent by the first
node comprises sending messaging to the home agent by a serving gateway.
6. The method of claim 5, wherein sending the messaging by the serving gateway
comprises sending a proxy registration request message.
7. The method of claim 6, wherein receiving the IP address comprises receiving the IP
address in a proxy registration response message.
8. The method of claim 1, wherein sending the messaging to the home agent by the first
node comprises sending a proxy registration request to the home agent by a packet data
network gateway.
9. The method of claim 1, further comprising the first node sending the IP address for
receipt by the mobile station.
10. The method of claim 9, wherein sending the IP address comprises sending the IP
address from one of a packet data network gateway and a serving gateway.
11. The method of claim 1, further comprising:
in response to transfer of the session of the mobile station from a first serving gateway
to a second serving gateway, sending an address of the home agent to the second serving
gateway.
12. The method of claim 1, further comprising:
in response to transfer of the session of the mobile station from a first serving gateway
to a second serving gateway, sending, to the second serving gateway, an address of a packet
data network gateway that maintains a binding of the mobile station to the mobile station's
current home agent.
13. The method of claim 1, further comprising:
in response to transfer of the mobile station to an access network of the second service
domain, providing a serving node in the second service domain an address of the home agent.
14. A method comprising:
receiving, by a home agent from a first node of a first service domain, messaging
requesting allocation of an Internet Protocol (IP) address for a mobile station that is attached
to a wireless access network of the first service domain, wherein the home agent is in a
second service domain that is of a different type than the first service domain; and
sending, by the home agent to the first node, the IP address allocated to the mobile
station in the second service domain, wherein the IP address is allocated in response to the
messaging, and wherein services provided to the mobile station are anchored in the second
service domain.
15. The method of claim 14, wherein receiving the messaging from the first node
comprises receiving proxy registration request messaging from one of a serving gateway and
a packet data network gateway.
16. The method of claim 15, wherein receiving the proxy registration request messaging
from one of the serving gateway and the packet data network gateway comprises receiving
the proxy registration request messaging from one of the serving gateway and the packet data
network gateway in a Long Term Evolution (LTE) service domain.
17. The method of claim 14, wherein receiving the messaging from the first node
comprises receiving a DHCP (Dynamic Host Configuration Protocol) message from a packet
data network gateway.
18. A first node configured to operate in a first service domain, comprising:
an interface to a home agent in a second service domain that is of a different type than
the first service domain; and
a processor to:
receive information associated with a mobile station to allow for establishment
of a session for the mobile station that is attached to a first wireless access network in the first
service domain;
in response to the received information, send messaging to the home agent in a
second service domain that is of a different type than the first service domain; and
receive an Internet Protocol (IP) address allocated to the mobile station in the
second service domain, wherein the IP address is allocated in response to the messaging, and
wherein services provided to the mobile station are anchored in the second service domain.
19. The first node of claim 18, wherein the first service domain is a Long Term Evolution
(LTE) domain.
20. The first node of claim 19, wherein the second service domain is a 3GPP2 (Third
Generation Partnership 2) service domain.
21. The first node of claim 18, comprising one of a packet data network gateway and a
serving gateway.
22. The first node of claim 18, wherein the messaging comprises one of a proxy
registration request message and a DHCP (Dynamic Host Configuration Protocol) message.
23. A home agent node configured to operate in a first service domain, comprising:
an interface to a first node in a second service domain that is of a different type than
the first service domain; and
a processor to:
receive from the first node messaging requesting allocation of an Internet
Protocol (IP) address for a mobile station that is attached to a wireless access network of the
second service domain; and
send the IP address allocated to the mobile station in the second service
domain, wherein the IP address is allocated in response to the messaging, and wherein
services provided to the mobile station are anchored in the first service domain.
24. The home agent node of claim 23, wherein the messaging comprises a proxy
registration request messaging received from one of a serving gateway and a packet data
network gateway.
25. The home agent node of claim 23, wherein the messaging comprises a DHCP
(Dynamic Host Configuration Protocol) message received from a packet data network
gateway.
26. The home agent node of claim 25, wherein the DHCP message is received over a
GRE (Generic Routing Encapsulation) tunnel.

A first node receives information associated
with a mobile station to allow for establishment
of a session for the mobile station that is attached
to a first wireless access network in a first service
domain. In response to the received information,
the first node sends messaging to a home agent
in a second service domain that is of a different type
than the first service domain. The first node receives,
from the home agent, an Internet Protocol (IP) address
allocated to the mobile station in the second
service domain, where the IP address is allocated in
response to the messaging, and where services provided
to the mobile station are anchored in the second
service domain.