NOKIA, INC. (6000 Connection Drive, Irving, TX, 75039, US)
What is claimed:
1. An inter-access handover method, comprising:
exchanging a handover mobility signal between a user equipment
(UE) and a new gateway;
transmitting information parameters to an old gateway in response to
the handover mobility signal;
transmitting the information parameters from the old gateway to an
old policy control function;
requesting session information of an ongoing session from an
application function by the old policy control function;
transmitting, based on the information parameters, the session
information, possible service or subscription related information, and/or an
IP address of the new gateway from the application function or the old
policy control function to a new policy control function; and
transmitting an authorization decision from the new policy control
function to the new gateway to continue the session through the new
gateway and the new policy control function.
2. The handover method as recited in claim 1, wherein the
transmitting of the information parameters to the old gateway comprises one
of transmitting the information parameters from the UE to the old gateway
in response to the handover mobility signal, and transmitting the information
parameters from the new gateway to the old gateway in response to the handover mobility signal.
3. The handover method as recited in claim I 5 wherein the
handover mobility signal from the UE to the new gateway comprises an IP
address or identity information of the old gateway, the method further
comprising:
using by the new gateway the IP address or the identification
information of the old gateway to find the old gateway.
4. The handover method as recited in claim 1, wherein the
information parameters comprise identity information associated with the
new gateway, an IP address of the new gateway, an IP address associated
with the new policy control function, and/or an IP address of the application
function.
5. The handover method as recited in claim 1 , further
comprising:
setting a service between the UE and the application function;
transmitting a request for a bearer establishment from the UE to the
old gateway;
accepting the request at the old gateway and assigning an IP address
to the UE;
requesting an authorization by the old gateway to the old policy control function of at least one service and rules information associated with
the UE;
authorizing the at least one service and policy decisions by the old
policy control function; and
sending the policy decisions back to the old gateway to enforce the
policy decisions and acknowledge the bearer establishment request.
6. The handover method as recited in claim 1, wherein the
session comprises one or a plurality of different IP data flows with specific
requirements for bearer resources.
7. The handover method as recited in claim 1, further
comprising:
exchanging session information between the old policy control
function and the application function in order to receive the subscription
related information comprising information about at least one service for the
UE and rules information comprising Policy and Charging Control (PCC)
rales information.
8. The handover method as recited in claim 1 , wherein the
requesting for session information further comprises providing the
information parameters to the application function.
9. The handover method as recited in claim 1 , wherein the
requesting for session information from the old policy control function
comprises service or subscription related information to exclude a separate
request from the new policy control function for the subscription related
information from subscriber registers.
10. The handover method as recited in claim 1, wherein, if the IP
address of the new policy control function is in the request from the old
policy control function, the application function uses the IP address of the
new policy control function as a contact address to the new policy control
function.
11. The handover method as recited in claim 1 , wherein, if the IP
address of the new policy control function is not included in the request but
a parameter is included in the request indicative of a new type of handover
access, further comprising:
providing a need to use a new policy control function to continue
with the handover session; and
determining by the application function the IP address of the new
policy control function from the parameter and the IP address of the UE or
other identity information available from the UE.
12. An inter-access handover method, comprising: transmitting a handover mobility signal from a user equipment (UE)
to a new gateway;
transmitting information parameters from the new gateway through
the UE to an old gateway in response to the handover mobility signal;
transmitting, based on the information parameters, mobility signaling
parameters from the old gateway through the UE to the new gateway, the
mobility signaling parameters comprising an IP address of an old policy
control function and/or an IP address of an application function;
reporting the mobility signaling parameters from the new gateway to
a new policy control function to request authorization for at least one
ongoing session; and
transmitting an authorization decision from the new policy control
function to the new gateway to continue the at least one ongoing session
through the new gateway and the new policy control function.
13. The handover method as recited in claim 12, further
comprising:
transmitting a session parameter request from the new policy control
function to an application function; and
transmitting service or subscription related information from the
application function to the new policy control function in response to the
session parameter request.
14. The handover method as recited in claim 12, further
comprising:
transmitting an authorization parameter request from the new policy
control function to an old policy control function requesting authorization
parameters comprising service or subscription related data, and/or a current
authorization decision of the at least one ongoing session;
transmitting the authorization parameters from the old policy control
function to the new policy control function; and
performing the authorization decision by the new policy control
function based on the authorization parameters.
15. A direct inter-access handover method, comprising:
transmitting a handover mobility signal from a user equipment (UE)
to a new gateway;
transmitting information parameters from the new gateway to the UE
in response to the handover mobility signal;
transmitting an information request from the new gateway to an old
gateway;
transmitting an information response from the old gateway to the new
gateway, the information response comprising the information parameters
including an IP address of an old policy control function and/or an IP
address of an application function;
transmitting, based on the information response, mobility signaling parameters from the new gateway to a new policy control function to request
authorization for at least one ongoing session; and
transmitting an authorization decision from the new policy control
function to the new gateway to continue the at least one ongoing session
through the new gateway and the new policy control function.
16. The direct inter-access handover method as recited in claim
15, further comprising:
transmitting a session parameter request from the new policy control
function to the application function; and
transmitting service or subscription related information from the
application function to the new policy control function in response to the
session parameter request.
17. The direct inter-access handover method as recited in claim
15, further comprising:
transmitting an authorization parameter request from the new policy
control function to the old policy control function requesting authorization
parameters comprising service or subscription related data and/or a current
authorization decision of the at least one ongoing session;
transmitting the authorization parameters from the old policy control
function to the new policy control function; and
performing the authorization decision by the new policy control function based on the authorization parameters.
18. The direct inter-access handover method as recited in claim
15, wherein the handover mobility signal from the UE to the new gateway
comprises an IP address or identity information of the old gateway, the
direct inter-access handover method further comprising:
using by the new gateway the IP address or the identity information
of the old gateway to find the old gateway.
19. A computer program embodied on a computer readable
medium for performing an inter-access handover, the computer program
being configured to perform:
exchanging a handover mobility signal between a user equipment
(UE) and a new gateway;
transmitting information parameters to an old gateway in response to
the handover mobility signal;
transmitting the information parameters from the old gateway to an
old policy control function;
requesting session information of an ongoing session from an
application function by the old policy control function;
transmitting, based on the information parameters, the session
information, possible service or subscription related information, and/or an
IP address of the new gateway from the application function to a new policy control function; and
transmitting an authorization decision from the new policy control
function to the new gateway to continue the session through the new
gateway and the new policy control function.
20. The computer program as recited in claim 19, wherein the
transmitting of the information parameters to the old gateway comprises one
of transmitting the information parameters from the UE to the old gateway
in response to the handover mobility signal, and transmitting the information
parameters from the new gateway to the old gateway in response to the
handover mobility signal.
21. The computer program as recited in claim 19, wherein the
handover mobility signal from the UE to the new gateway comprises an IP
address or identity information of the old gateway, the computer program
further comprising:
using by the new gateway the IP address or the identity information
of the old gateway to find the old gateway.
22. The computer program as recited in claim 19, wherein the
information parameters comprise identity information associated with the
new gateway, an IP address of the new gateway, an IP address associated
with the new policy control function, and/or an IP address of the application function.
23. The computer program as recited in claim 19, further
comprising:
setting a service between the UE and the application function;
transmitting a request for a bearer establishment from the UE to the
old gateway;
accepting the request at the old gateway and assigning an IP address
to the UE;
requesting an authorization by the old gateway to the old policy
control function of at least one service and rules information associated with
the UE;
authorizing the at least one service and policy decisions by the old
policy control function; and
sending the policy decisions back to the GWl to enforce the policy
decisions and acknowledge the bearer establishment request.
24. The computer program as recited in claim 19, wherein the
session comprises one or a plurality of different IP data flows with specific
requirements for bearer resources.
25. The computer program as recited in claim 19, further
comprising: exchanging session information between the old policy control
function and the application function in order to receive the subscription
related information comprising information about at least one service for the
UE and rules information comprising Policy and Charging Control (PCC)
rules information.
26. The computer program as recited in claim 19, wherein the
requesting for session information further comprises providing the
information parameters to the application function.
27. The computer program as recited in claim 19, wherein the
requesting for session information from the old policy control function
comprises service or subscription related information to exclude a separate
request from the new policy control function for the subscription related
information from subscriber registers.
28. The computer program as recited in claim 19, wherein, if the
IP address of the new policy control function is in the request from the old
policy control function, the application function uses the IP address of the
new policy control function as a contact address to the new policy control
function.
29. The computer program as recited in claim 19, wherein, if the IP address of the new policy control function is not included in the request
but a parameter is included in the request indicative of a new type of
handover access, further comprising:
providing a need to use a new policy control function to continue
with the handover session; and
determining by the application function the IP address of the new
policy control function from the parameter and the IP address of the UE or
other identity information available from the UE.
30. A computer program embodied on a computer readable
medium for performing an inter-access handover, the computer program
being configured to perform the steps of:
transmitting a handover mobility signal from a user equipment (UE)
to a new gateway;
transmitting information parameters from the new gateway through
the UE to an old gateway in response to the handover mobility signal;
transmitting, based on the information parameters, mobility signaling
parameters from the old gateway through the UE to the new gateway, the
mobility signaling parameters comprising an IP address of an old policy
control function and/or an IP address of an application function;
reporting the mobility signaling parameters from the new gateway to
a new policy control function to request authorization for at least one
ongoing session; and transmitting an authorization decision from the new policy control
function to the new gateway to continue the at least one ongoing session
through the new gateway and the new policy control function.
31. The computer program as recited in claim 30, further
comprising:
transmitting a session parameter request from the new policy control
function to an application function; and
transmitting service or subscription related information from the
application function to the new policy control function in response to the
session parameter request.
32. The computer program as recited in claim 30, further
comprising:
transmitting an authorization parameter request from the new policy
control function to an old policy control function requesting authorization
parameters comprising service or subscription related data, and/or a current
authorization decision of the at least one ongoing session;
transmitting the authorization parameters from the old policy control
function to the new policy control function; and
performing the authorization decision by the new policy control
function based on the authorization parameters.
33. A computer program embodied on a computer readable
medium for performing a direct inter-access handover, the computer
program being configured to perform the steps of:
transmitting a handover mobility signal from a user equipment (UE)
to a new gateway;
transmitting information parameters from the new gateway to the UE
in response to the handover mobility signal;
transmitting an information request from the new gateway to an old
gateway;
transmitting an information response from the old gateway to the new
gateway, the information response comprising the information parameters
including an IP address of an old policy control function and/or an IP
address of an application function;
transmitting, based on the information response, mobility signaling
parameters from the new gateway to a new policy control function to request
authorization for at least one ongoing session; and
transmitting an authorization decision from the new policy control
function to the new gateway to continue the at least one ongoing session
through the new gateway and the new policy control function.
34. The computer program as recited in claim 33, further
comprising:
transmitting a session parameter request from the new policy control function to the application function; and
transmitting service or subscription related information from the
application function to the new policy control function in response to the
session parameter request.
35. The computer program as recited in claim 33 , further
comprising:
transmitting an authorization parameter request from the new policy
control function to the old policy control function requesting authorization
parameters comprising service or subscription related data and/or a current
authorization decision of the at least one ongoing session;
transmitting the authorization parameters from the old policy control
function to the new policy control function; and
performing the authorization decision by the new policy control
function based on the authorization parameters.
36. The computer program as recited in claim 33, wherein the
handover mobility signal from the UE to the new gateway comprises an IP
address or identity information of the old gateway, the computer program
further comprising:
using by the new gateway the IP address or the identity information
of the old gateway to find the old gateway.
37. An inter-access handover system, comprising:
a new gateway configured to receive a handover mobility signal from
a user equipment (UE) and to transmit information parameters to an old
gateway in response to the handover mobility signal;
an old policy control function configured to receive the information
parameters from the old gateway and configured to receive session
information of an ongoing session;
an application function; and
a new policy control function configured to receive from the
application function or the old policy control function, based on the
information parameters, the session information, possible service or
subscription related information, and/or an IP address of the new gateway,
and configured to transmit an authorization decision to the new gateway to
continue the session through the new gateway and the new policy control
function.
38. The inter-access handover system as recited in claim 37,
wherein the new gateway is configured to transmit the information
parameters to the old gateway by performing one of transmitting the
information parameters from the UE to the old gateway in response to the
handover mobility signal, and transmitting the information parameters from
the new gateway to the old gateway in response to the handover mobility
signal.
39. The inter-access handover system as recited in claim 37,
wherein the handover mobility signal from the UE to the new gateway
comprises an IP address or identity information of the old gateway, and
wherein the new gateway uses the IP address or the identity information of
the old gateway to find the old gateway.
40. The inter-access handover system as recited in claim 37,
wherein the information parameters comprise identity information
associated with the new gateway, an IP address of the new gateway, an IP
address associated with the new policy control function, and/or an IP address
of the application function.
41. An inter-access handover system, comprising:
a new gateway configured to receive a handover mobility signal from
a user equipment (UE);
an old gateway configured to receive information parameters from the
new gateway through the UE in response to the handover mobility signal
and configured to transmit through the UE to the new gateway, based on the
information parameters, mobility signaling parameters, the mobility
signaling parameters comprising an IP address of an old policy control
function and/or an IP address of an application function; and
a new policy control function configured to receive the mobility signaling parameters from the new gateway and a request for authorization
for at least one ongoing session, and configured to transmit an authorization
decision to the new gateway to continue the at least one ongoing session
through the new gateway and the new policy control function.
42. The inter-access handover system as recited in claim 41 ,
wherein the new policy control function is further configured to transmit a
session parameter request to an application function, and the application
function is configured to transmit service or subscription related information
to the new policy control function in response to the session parameter
request.
43. The inter-access handover system as recited in claim 41,
wherein the new policy control function is further configured to request
authorization parameters, and the old policy control function is further
configured to transmit the authorization parameters comprising service or
subscription related data, and/or a current authorization decision of the at
least one ongoing session.
44. The inter-access handover system as recited in claim 41,
wherein the old policy control function is further configured to transmit the
authorization parameters to the new policy control function, and the new
policy control function is configured to perform the authorization decision based on the authorization parameters.
45. A direct inter-access handover system, comprising:
a new gateway configured to receive a handover mobility signal from
a user equipment (UE) and configured to transmit information parameters to
the UE in response to the handover mobility signal;
an old gateway configured to receive an information request from the
new gateway and configured to transmit an information response comprising
the information parameters to the new gateway, the information response
including an IP address of an old policy control function and/or an IP
address of an application function; and
a new policy control function configured to receive from the new
gateway, based on the information response, mobility signaling parameters
to request authorization for at least one ongoing session, and configured to
transmit an authorization decision to the new gateway to continue the at least
one ongoing session through the new gateway and the new policy control
function.
46. The direct inter-access handover system as recited in claim 45,
wherein the new policy control function is configured to transmit a session
parameter request to the application function, and the application function is
configured to transmit service or subscription related information to the new
policy control function in response to the session parameter request.
47. The direct inter-access handover system as recited in claim 45,
wherein the new policy control function is configured to transmit an
authorization parameter request to the old policy control function requesting
authorization parameters comprising service or subscription related data
and/or a current authorization decision of the at least one ongoing session.
48. The direct inter-access handover system as recited in claim 45,
wherein the old policy control function is configured to transmit the
authorization parameters to the new policy control function, and the new
policy control function is configured to perform the authorization decision
based on the authorization parameters.
49. The inter-access handover system as recited in claim 45,
wherein the handover mobility signal from the UE to the new gateway
comprises an IP address or identity information of the old gateway and the
new gateway uses the IP address or the identity information of the old
gateway to find the old gateway.
50. An inter-access handover method, comprising:
transmitting information parameters from a gateway to an old policy
control function in response to a handover mobility signal from a user
equipment (UE); requesting session information of an ongoing session from an
application function by the old policy control function;
transmitting, based on the information parameters, the session
information, possible service or subscription related information, and/or an
IP address of the gateway from the application function or the old policy
control function to a new policy control function; and
transmitting an authorization decision from the new policy control
function to the gateway to continue the session through the new policy
control function.
51. An inter-access handover method, comprising:
transmitting mobility signaling parameters through a user equipment
(UE) to a gateway in response to a handover mobility signal from the UE,
the mobility signaling parameters comprising an IP address of an old policy
control function and/or an IP address of an application function;
reporting the mobility signaling parameters from the gateway to a
new policy control function to request authorization for at least one ongoing
session; and
transmitting an authorization decision from the new policy control
function to the gateway to continue the at least one ongoing session through
the new policy control function.
52. A direct inter-access handover method, comprising: transmitting a handover mobility signal from a user equipment (UE)
to a gateway;
transmitting information parameters from the gateway to the UE in
response to the handover mobility signal;
transmitting, based on the information parameters, mobility signaling
parameters from the gateway to a new policy control function to request
authorization for at least one ongoing session, the information parameters
including an IP address of an old policy control function and/or an IP
address of an application function; and
transmitting an authorization decision from the new policy control
function to the gateway to continue the at least one ongoing session through
the new policy control function.
53. An inter-access handover system, comprising:
a gateway configured to transmit information parameters in response
to a handover mobility signal fro ma user equipment (UE);
an old policy control function configured to receive the information
parameters from the gateway and configured to receive session information
of an ongoing session;
an application function; and
a new policy control function configured to receive from the
application function or the old policy control function, based on the
information parameters, the session information, possible service or subscription related information, and/or an IP address of the gateway, and
configured to transmit an authorization decision to the gateway to continue
the session through the new policy control function.
54. An inter-access handover system, comprising:
a gateway configured to receive a handover mobility signal from a
user equipment (UE), and configured to transmit, based on information
parameters, mobility signaling parameters, wherein the mobility signaling
parameters comprise an IP address of an old policy control function and/or
an IP address of an application function; and
a new policy control function configured to receive the mobility
signaling parameters from the gateway and a request for authorization for at
least one ongoing session, and configured to transmit an authorization
decision to the gateway to continue the at least one ongoing session through
the new policy control function.
55. A direct inter-access handover system, comprising:
a gateway configured to receive a handover mobility signal from a
user equipment (UE), and configured to transmit information parameters to
the UE in response to the handover mobility signal; and
a new policy control function configured to receive, based on the
information parameters; ' mobility signaling parameters from the gateway
requesting authorization for at least one ongoing session, the information parameters including an IP address of an old policy control function and/or
an IP address of an application function, and configured to transmit an
authorization decision to the gateway to continue the at least one ongoing
session through the new policy control function. |
TITLE OF THE INVENTION
INTER-ACCESS HANDOVER WITH ACCESS SPECIFIC POLICY CONTROL FUNCTIONS
BACKGROUND OF THE INVENTION Field of the Invention
[0001] The present invention relates to a system and method to exchange information relating to mobility management during an inter-access handover, more particularly, a system and method to exchange information when an inter-access handover occurs during an ongoing policy and/or charging controlled session.
Description of the Related Art
[0002] A Next Generation Network (NGN) IP Multimedia Subsystem (IMS) supports provision of Sessions Initiation Protocol (SιP)-based multimedia services to NGN terminals. IMS also supports the provision of Public Switched Telephony Network (PSTN)/Integrated Services Digital
Network (ISDN) simulation services. Various access technologies may be used to access IMS, for example, General Packet Radio Service (GPRS), Digital Subscriber Line (xDSL), and Wireless Local Area Network (WLAN). Policy control functions have been standardized for the GPRS access (in 3 rd Generation Partnership Project (3 GPP) known as Policy Decision Function (PDF) or as Policy and Charging Rules Function (PCRF), when charging control is included), are being standardized for, at least, the WLAN access.
[0003] In general, a system structure of a communication network is such that a subscriber's user equipment, such as a mobile station, a mobile phone, a fixed phone, a personal computer (PC), a laptop, a personal digital assistant (PDA) or the like, is connected via transceivers and interfaces, such as an air interface, a wired interface or the like, to an access network subsystem. The access network subsystem controls the communication connection to and from the user equipment and is connected via an interface to a corresponding core or backbone network subsystem. The core (or backbone) network subsystem switches data transmitted via the communication connection to a destination, such as another user equipment, a service provider (server/proxy), or another communication network. It is to be noted that the core network subsystem may be connected to a plurality of access network subsystems. Depending on the used communication network, the actual network structure may vary, as known for those skilled in the art and defined in respective specifications, for example, for Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communication (GSM) and the like.
[0004] Generally, for properly establishing and handling a communication
connection between network elements such as the user equipment and another user equipment, a database, a server, etc., one or more intermediate network elements such as support nodes or service nodes are involved. One or more connection parameters are used for defining connection characteristics. This includes, for example, a packet based data transmission
protocol information, such as a PDP (Packet Data Protocol) context information, for example, information about quality of service (QoS) requested or provided, charging-related information, such as a charging class, etc. IMS specific information, Authorization Token or UE IP address or user/UE identity and Flow ID(s) are used as binding information when requesting QoS authorization for a PDP context.
[0005] When the communication connection is initialized, an authorization for the connection parameters of services is requested from a policy control entity which decides on connection parameters to be authorized for the communication connection and on service types which can be provided for the communication connection.
[0006] Both, push and pull modes may be used for obtaining an authorization decision from a policy decision function (PDF/Service Policy Decision Function (SPDF)/PCRF) to a gateway. In a push operation, the PDF sends the information without being requested by the gateway. In a pull operation, the gateway requests the PDF to send the information to the gateway.
[0007] When a typical inter-access handover, that is, a handover from a Digital Subscriber Line (xDSL) access to General Packet Radio Service (GPRS) access or vice versa, occurs during an ongoing policy and/or charging controlled session, the policy control entity changes. Accordingly, problems occur in which a session control element, such as a Proxy Call Session Control Function (P-CSCF) in IMS or an Application Function
(AF), needs to determine or identify a new policy control entity. A system and method are needed that would allow the AF/P-CSCF to obtain an IP address of the new PCRF. The system and method would allow the new policy control entity to obtain session related parameters for making an authorization decision for a new session, to obtain subscriber or service specific parameters, and/or to find the new gateway. The new gateway would need to be provided the ability to find the application function used by the session. Also, for an existing session being transferred, the system and method would need to provide the policy control entity the ability to obtain an already made authorization decision.
SUMMARY OF THE INVENTION
[0010] In accordance with an embodiment of the present invention, there
is provided an inter- access handover method and computer program
embodied on a computer readable medium for performing an inter-access
handover including exchanging a handover mobility signal between a user
equipment (UE) and a new gateway, transmitting information parameters
from the new gateway to an old gateway in response to the handover
mobility signal, transmitting the information parameters from the old
gateway to an old policy control function, and requesting session
information of an ongoing session from an application function by the old
policy control function. The inter-access handover method and the
computer program embodied on a computer readable medium for
performing an inter-access handover further include transmitting, based on
the information parameters, the session information, possible service or
subscription related information, and/or an IP address of the new gateway
from the application function or the old policy control function to a new
policy control function, and transmitting an authorization decision from the
new policy control function to the new gateway to continue the session
through the new gateway and the new policy control function.
[0011] In accordance with an embodiment of the present invention, there
is provided an inter-access handover method and computer program
embodied on a computer readable medium for performing an inter-access
handover including transmitting a handover mobility signal from a user
equipment (UE) to a new gateway, transmitting information parameters from
the new gateway through the UE to an old gateway in response to the
handover mobility signal, transmitting, based on the information parameters,
mobility signaling parameters from the old gateway through the UE to the
new gateway, the mobility signaling parameters including an IP address of
an old policy control function and/or an IP address of an application
function, and reporting the mobility signaling parameters from the new
gateway to a new policy control function to request authorization for at least
one ongoing session. The inter-access handover method and the computer
program embodied on a computer readable medium for performing an inter-
access handover also include transmitting an authorization decision from the
new policy control function to the new gateway to continue the at least one
ongoing session through the new gateway and the new policy control
function.
[0012] In accordance with an embodiment of the present invention, there
is provided a direct inter-access handover method and computer program
embodied on a computer readable medium for performing a direct inter-
access handover including transmitting a handover mobility signal from a
user equipment (UE) to a new gateway, transmitting information parameters
from the new gateway to the UE in response to the handover mobility signal,
transmitting an information request from the new gateway to an old
gateway, transmitting an information response from the old gateway to the
new gateway, the information response comprising the information
parameters including an IP address of an old policy control function and/or
an IP address of an application function, transmitting, based on the
information response, mobility signaling parameters from the new gateway
to a new policy control function to request authorization for at least one
ongoing session, and transmitting an authorization decision from the new
policy control function to the new gateway to continue the at least one
ongoing session through the new gateway and the new policy control
function.
[0013] In accordance with an embodiment of the present invention, there
is provided an inter-access handover system including a new gateway
configured to receive a handover mobility signal from a user equipment
(UE) and to transmit information parameters to an old gateway in response
to the handover mobility signal. An old policy control function is
configured to receive the information parameters from the old gateway and
configured to receive session information of an ongoing session. A new
policy control function is configured to receive from an application function
or the old policy control function, based on the information parameters, the
session information, possible service or subscription related information,
and/or an IP address of the new gateway, and configured to transmit an
authorization decision to the new gateway to continue the session through
the new gateway and the new policy control function.
[0014] In accordance with an embodiment of the present invention, there
is provided an inter-access handover system, including a new gateway
configured to receive a handover mobility signal from a user equipment
(UE), an old gateway configured to receive information parameters from the
new gateway through the UE in response to the handover mobility signal
and configured to transmit through the UE to the new gateway, based on the
information parameters, mobility signaling parameters, the mobility
signaling parameters including an IP address of an old policy control
function and/or an IP address of an application function, and a new policy
control function configured to receive the mobility signaling parameters
from the new gateway and a request for authorization for at least one
ongoing session, and configured to transmit an authorization decision to the
new gateway to continue the at least one ongoing session through the new
gateway and the new policy control function.
[0015] In accordance with an embodiment of the present invention, there
is provided a direct inter-access handover system, including a new gateway
configured to receive a handover mobility signal from a user equipment
(UE) and configured to transmit information parameters to the UE in
response to the handover mobility signal, an old gateway configured to
receive an information request from the new gateway and configured to
transmit an information response comprising the information parameters to
the new gateway, the information response including an IP address of an old
policy control function and/or an IP address of an application function, and a
new policy control function configured to receive from the new gateway,
based on the information response, mobility signaling parameters to request
authorization for at least one ongoing session, and configured to transmit an
authorization decision to the new gateway to continue the at least one
ongoing session through the new gateway and the new policy control
function.
[0016] In accordance with an embodiment of the present invention, there
is provided an inter-access handover method including transmitting
information parameters from a gateway to an old policy control function in
response to a handover mobility signal from a user equipment (UE),
requesting session information of an ongoing session from an application
function by the old policy control function, transmitting, based on the
information parameters, the session information, possible service or
subscription related information, and/or an IP address of the gateway from
the application function or the old policy control function to a new policy
control function, and transmitting an authorization decision from the new
policy control function to the gateway to continue the session through the
new policy control function.
[0017] In accordance with an embodiment of the present invention, there
is provided an inter-access handover method including transmitting mobility
signaling parameters through a user equipment (UE) to a gateway in
response to a handover mobility signal from the UE, the mobility signaling
parameters including an IP address of an old policy control function and/or
an IP address of an application function, reporting the mobility signaling
parameters from the gateway to a new policy control function to request
authorization for at least one ongoing session, and transmitting an
authorization decision from the new policy control function to the gateway
to continue the at least one ongoing session through the new policy control
function.
[0018] In accordance with an embodiment of the present invention, there
is provided an direct inter-access handover method including transmitting a
handover mobility signal from a user equipment (UE) to a gateway,
transmitting information parameters from the gateway to the UE in response
to the handover mobility signal, transmitting, based on the information
parameters, mobility signaling parameters from the gateway to a new policy
control function to request authorization for at least one ongoing session, the
information parameters including an IP address of an old policy control
function and/or an IP address of an application function, and transmitting an
authorization decision from the new policy control function to the gateway
to continue the at least one ongoing session through the new policy control
function.
[0019] In accordance with an embodiment of the present invention, there
is provided an inter-access handover system including a gateway configured
to transmit information parameters in response to a handover mobility signal
fro ma user equipment (UE), an old policy control function configured to
receive the information parameters from the gateway and configured to
receive session information of an ongoing session, an application function,
and a new policy control function configured to receive from the application
function or the old policy control function, based on the information
parameters, the session information, possible service or subscription related
information, and/or an IP address of the gateway, and configured to transmit
an authorization decision to the gateway to continue the session through the
new policy control function.
[0020] In accordance with an embodiment of the present invention, there
is provided an inter-access handover system, including a gateway configured
to receive a handover mobility signal from a user equipment (UE) 5 and
configured to transmit, based on information parameters, mobility signaling
parameters, wherein the mobility signaling parameters include an IP address
of an old policy control function and/or an IP address of an application
function, and a new policy control function configured to receive the
mobility signaling parameters from the gateway and a request for
authorization for at least one ongoing session, and configured to transmit an
authorization decision to the gateway to continue the at least one ongoing
session through the new policy control function.
[0021] In accordance with an embodiment of the present invention, there
is provided a direct inter-access handover system, including a gateway
configured to receive a handover mobility signal from a user equipment
(UE), and configured to transmit information parameters to the UE in
response to the handover mobility signal, and a new policy control function
configured to receive, based on the information parameters, mobility
signaling parameters from the gateway requesting authorization for at least
one ongoing session, the information parameters including an IP address of
an old policy control function and/or an IP address of an application
function, and configured to transmit an authorization decision to the gateway
to continue the at least one ongoing session through the new policy control
function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Further embodiments, details, advantages and modifications of the
present invention will become apparent from the following detailed
description of the preferred embodiments which is to be taken in conjunction
with the accompanying drawings, in which:
[0023] FIG. 1 illustrates a position of the IMS in an overall NGN
architecture, in accordance with an embodiment of the present invention.
[0024] FIG. 2 illustrates a Policy and Charging Control (PCC) system
architecture, in accordance with an embodiment of the present invention.
[0025] FIG. 3 illustrates an inter-access handover via a mobile user
equipment (UE) with access specific policy control functions between an old
gateway and AF/P-CSCF and between a new gateway and AF/P-CSCF, in
accordance with an embodiment of the present invention.
[0026] FIG. 4 illustrates a direct inter-access handover signaling between
the old gateway and the new gateway, in accordance with an embodiment of
the present invention.
[0027] FIG. 5 illustrates an inter-access handover via the mobile user
equipment (UE) with access specific policy control functions between an old
gateway and AF/P-CSCF and between a new gateway and AF/P-CSCF, in
accordance with an embodiment of the present invention.
[0028] FIG. 6 illustrates a direct inter-access handover signaling between
the old gateway and the new gateway, in accordance with an embodiment of
the present invention.
[0029] FIG. 7 illustrates an inter-access handover via a mobile user
equipment (UE) with access specific policy control functions between a
single gateway and AF/P-CSCF, in accordance with an embodiment of the
present invention.
[0030] FIG. 8 illustrates an inter-access handover method, in accordance
with an embodiment of the present invention.
[0031] FIG. 9 illustrates the inter-access handover method, in accordance
with an alternative embodiment of the present invention.
[0032] FIG. 10 illustrates a direct inter-access handover method, in
accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are illustrated in
the accompanying drawings. The embodiments of the present invention
described below provide a system and method to exchange information
relating to mobility management during an inter-access handover. The
system and method exchange information when an inter-access handover
occurs during an ongoing policy and/or charging controlled session.
[0034] The NGN IMS, also known as "Core IMS" is a subset of 3 rd
Generation Partnership Project (3GPP) IMS. Core IMS is restricted to
session control functionalities. Application Servers (AS) and
transport/media functions such as the Multimedia Resource Function
Processor function (MRFP) and the IP Multimedia Gateway Functions (IM-
MGW) are considered to be outside the "Core IMS."
[0035] FIG. 1 illustrates a position of the IMS in an overall NGN
architecture, in accordance with an embodiment of the present invention.
The IMS provides services to a User Equipment (UE) connected via a
plurality of IP connectivity access networks. FIG. 1 illustrates a case where
an IMS subsystem provides services to the UE connected to a fixed
broadband access network and to other user equipment connected via GPRS
based IP-CAN.
[0036] FIG. 2 illustrates a Policy and Charging Control (PCC) system
architecture, in accordance with an embodiment of the present invention.
The PCC architecture includes a Policy and Charging Enforcement Function
(PCEF) in a gateway (GW), a Policy Control and Charging Rules Function
(PCRF), an Application Function (AF), an Online Charging System (OCS),
an Offline Charging System (OFCS), and a Subscription Profile Repository
(SPR). The PCC architecture may extend the architecture of an IP
Connectivity Access Network (IP-CAN), where the PCEF is a functional
entity in a gateway node implementing an IP access to a PDN (for instance,
for GPRS, GGSN, and for WLAN, the PDG). The PCRF provides network
control regarding service data flow detection, gating, QoS, and flow based
charging towards PCEF. The PCRF applies security procedures, as required
by the operator, before accepting service information from the AF. The
PCRF also decides how a certain service data flow is to be treated in the
PCEF and ensures that the PCEF user plane traffic mapping and treatment is
in accordance with a user's subscription profile.
[0037] Furthermore, the PCRF may check that the service information
provided by the AF is consistent with the operator defined policy rules
before storing service information. The service information may be used to
derive the QoS for a particular service. The PCRF may reject a request
received from the AF and, as a result, the PCRF may indicate, in the
response to the AF, that the service information cannot be accepted by the
PCRF. Subscription information may be used by the PCRF as basis for the
policy and charging control decisions. The subscription information may
apply to session based and non-session based services.
[0038] In turn, AF is a functional entity that communicates with the PCRF
to transfer dynamic session information. The transfer of the dynamic
session information is based on either an end user IP address and/or other
UE identity information the AF may include. One example of the AF is a
Proxy Call Session Control Function (P-CSCF).
[0039] Further, in FIG. 2, Reference point Rx between the AF and the
PCRF enables transport of application level session information from the AF
to PCRF. Such information may include, for instance, IP filter information
to identify service data flow for gating control and/or differentiated
charging, and media/application bandwidth requirements for Quality of
Service (QoS) control. Reference point Gx resides between the PCEF in the
GW and the PCRF to enable signaling of PCC rules, which govern the PCC
behavior and supports, for instance, initialization and maintenance of
connection, request for PCC rules from PCEF to PCRF, provision of the
PCC rules from PCRF to PCEF, and indication of Bearer Service
Termination from the PCEF to PCRF. Reference point Sp lies between the
SPR and the PCRF and allows the PCRF to request subscription information
related to bearer level policies from the SPR based on a subscriber
identification. The reference point Sp allows the SPR to notify the PCRF
when the subscription information has been changed if the PCRF has
requested such notification. Reference point Gy resides between the OCS
and the PCEF and allows online credit control for service data flow based
charging. Reference point Gz resides between the PCEF and the OFCS and
enables transport of service data flow based offline charging information.
[0040] FIG. 3 illustrates an inter-access handover via a mobile user
equipment (UE) with access specific policy control functions between an old
gateway and AF/P-CSCF and between a new gateway and AF/P-CSCF, in
accordance with an embodiment of the present invention. As illustrated in
FIG. 3, a mobile user equipment (UE) 100 exchanges information between
an old gateway (GWl) 20, an old Policy Control and Charging Rules
Function (PCRFl) 30, a new gateway (GW2) 40, a new Policy Control and
Charging Rules Function (PCRF2) 50, and an Application Function
(AF)/Proxy Call Session Control Function (P-CSCF) 60.
[0041] In order to support mobility, the GWl 20 needs to exchange
information with the GW2 40. Accordingly, at step 100, a mobile user
equipment (UE) 10 service is set-up between the UE 10 and the AF/P-CSCF
60 of a service provider. In order to initiate an application session, the set¬
up of the session and activation of the service require an establishment of a
bearer service to carry data packets of the session. The session may include
one or a plurality of different IP flows with specific requirements for bearer
resources. Accordingly, the UE 10 transmits a request for a bearer
establishment to the GWl 20. The GWl 20 accepts the request and assigns
an IP address to a user or subscriber of the UE 10.
[0042] At step 110, the GWl 20 determines that an authorization is
required and, accordingly, requests the authorization from the PCRFl 30 of
allowed service(s) and rules information associated with the UE 10, such as
Policy and Charging Control (PCC) rules. The request by a gateway is
known as a pull operation. At step 120, the PCRFl 30 may request from the
AF/P-CSCF 60 an update of the session related information, which PCRFl
30 has received earlier upon the session setup signaling, and/or from a
subscriber register (not shown) or from the AF/P-CSCF the subscriber's
subscription related information, the PCRFl 30 exchanges session
information with the AF/P-CSCF (and/or the subscriber register) in order to
receive the session and/or subscription related information. The AF/P-CSCF
would reply with the session and/or subscription related information
containing information about the allowed service(s) for the UE 10 and PCC
rules information. The PCRFl 30 would make authorization and policy
decisions and send such policy decisions back to the GWl 20. The GWl 20
would enforce the policy decisions, thereby acknowledging the bearer
establishment request. In an alternative, a push operation is used, i.e. the
PCRFl 30 sends the authorization information to the gateway GWl 20
without a prior request from the GWl 20.
[0043] At step 130, a mobility signaling is transmitted from the UE 10 to
the new gateway GW2 for the inter-access handover. At step 140, the GW2
40 transmits information parameters to the UE 10 to support mobility. Such
information parameters may include, for instance, identity associated with
the GW2 40, IP address of the GW2 40, IP address associated with the
PCRF2 50, and/or IP address of the AF/P-CSCF 60 to find the GW2 40.
[0044] At step 150, the UE 10 exchanges information with the GWl 20
for mobility. Specifically, the UE 10 exchanges the information parameters
with the GWl 20. At step 160, the GWl 20 sends an indication/report of the
handover with the information parameters to the old policy control function,
PCRFl 30. At step 170, upon processing of the information parameters, the
PCRFl 30 requests session information for the ongoing sessions from the
AF/P-CSCF 60 to be sent from the application function AF/P-CSCF 60 to
the new Policy and Charging Rules Function the PCRF2 50 based on the
information parameters. The request would also provide the information
parameters to the AF/P-CSCF 60. The request from the PCRFl 30 may also
include authorization information, e.g. an authorization made previously by
the PCRFl 30 for the session, or session related parameters. The request
from the PCRFl 30 may also include service or subscription related
information, thereby the PCRF2 50 would not need to issue a separate
request for this subscription related information from subscriber registers,
thus, saving processing time. Furthermore, if the IP address of the PCRF2
50 is in the request from the PCRFl 30, the AF/P-CSCF 60 uses the IP
address of the PCRF2 50 as a contact address to the PCRF2 50. On the
other hand, if the IP address of the PCRF2 50 is not included in the request
but a parameter is included in the request indicative of a new type of
handover access, and, consequently, indicative of a need to use a new PCRF
to continue with the HANDOVER session, the AF/P-CSCF 60 determines
the IP address of the new PCRF from the parameter and the IP address of the
UE 10 or other identity information available from the UE 10. After step
170, the inter-access handover proceeds to either step 180 or step 185.
[0045] In one aspect of the present invention, at step 180, the AF/P-CSCF
60 pushes the authorization information or session information and the
possible service or the subscription related information to the PCRF2 50.
The AF/P-CSCF 60 may also send IP address of the GW2 40 to enable the
PCRF2 50 to find the GW2 40. The inter-access handover proceeds to step
190.
[0046] In an alternative, at step 185, the PCRFl 30 sends an authorization
message including an authorization decision or session information and/or
subscriber data directly to the PCRF2 50 because the PCRFl 30 has the
information and the IP address of the PCRF2 50. In this instance, the
AF/CSCF 60 updates the PCRF related information, the session which is
now managed by the PCRF2 50 instead of the PCRFl 30, when receiving
the reporting message (step 170) from the PCRFl 30. The inter-access
handover proceeds to step 190.
[0047] At step 190, the PCRF2 50 sends an authorization decision to the
GW2 40 or, in the alternative, the GW2 40 may request the authorization
decision from the PCRF2 50. Accordingly, the GW2 40 enforces the policy
decision based on the PCRF2 50 authorization and the IP session may
continue through the new access (i.e., through the GW2 40 and the PCRF2
50).
[0048] FIG. 4 illustrates a direct inter-access handover signaling between
the old gateway, GWl 20, and the new gateway, GW2 40, in accordance
with an embodiment of the present invention. Similarly to the embodiment
illustrated in FIG. 3, FIG. 4 illustrates the mobile user equipment (UE) 100
exchanging information between the GWl 20, the old Policy Control and
Charging Rules Function (PCRFl) 30, the new gateway (GW2) 40, the new
Policy Control and Charging Rules Function (PCRF2) 50, and the
Application Function (AF)/Proxy Call Session Control Function (P-CSCF)
60.
[0049] The description corresponding to steps 100 to 120 described in
FIG. 3 are incorporated herein. From step 120, the handover proceeds to
step 230. At step 230, the mobility signaling is requested from the UE 10 to
the new gateway GW 2 for the inter-access handover and the GW2 40
transmits the information parameters to the UE 10 to support mobility. The
request from the UE 10 the GW2 40 may contain, in addition to other related
parameters, the IP address or identity information of the old gateway GWl
20. That is, the request from the UE 10 to the GW2 40 may include an IP
address or identity information of the GWl 20, in which the GW2 40 may
use the IP address or the identity information of the GWl 20 to find the
GWl 20.
[0050] For instance, in FIG. 4, the GW2 40 sends to the GWl 20
information parameters which may comprise identity associated with the
GW2 40, IP address of the GW2 40, and/or IP address associated with the
PCRF2 50. At step 250, the GWl 20 sends the indication/report of the
handover with the information parameters to the old policy control function,
PCRFl 30. At step 260, the PCRFl 30 requests session information for the
ongoing sessions from the AF/P-CSCF 60 to be sent from the application
function AF/P-CSCF 60 to the new Policy and Charging Rules Function, the
PCRF2 50. The request would also provide the information parameters to
the AF/P-CSCF 60. The request from the PCRFl 30 may also include
authorization information, e.g., an authorization made previously by the
PCRFl 30 for the session, or session related parameters. The request from
the PCRFl 30 may also include the service or the subscription related
information; thereby the PCRF2 50 would not need to issue a separate
request for this subscription related information from subscriber registers,
thus, saving processing time. Furthermore, if the IP address of the PCRF2
50 is in the request from the PCRFl 30, the AF/P-CSCF 60 uses the IP
address of the PCRF2 50 as a contact address to the PCRF2 50. On the
other hand, if the IP address of the PCRF2 50 is not included in the request
but a parameter is included in the request indicative of a new type of
handover access, and, consequently, indicative of a need to use a new PCRF
to continue with the HANDOVER session, the AF/P-CSCF 60 determines
the IP address of the new PCRF from the parameter and the IP address of the
UE 10 or other identity information available from the UE 10. After step
260, the inter-access handover proceeds to either step 270 or step 275.
[0051] In one aspect of the present invention, at step 270, the AF/P-CSCF
60 pushes the authorization information or session information and the
possible service or the subscription related information to the PCRF2 50.
The AF/P-CSCF 60 may also send IP address of the GW2 40 to enable the
PCRF2 50 to find the GW2 40.
[0052] In an alternative, at step 275, the PCRFl 30 sends an authorization
message including an authorization decision or session information and/or
subscriber data directly to the PCRF2 50 because the PCRFl 30 has the
information and the IP address of the PCRF2 50. In this instance, the
AF/CSCF 60 updates the PCRF related information, the session which is
now managed by the PCRF2 50 instead of the PCRFl 30, when receiving
the reporting message (step 260) from the PCRFl 30. The inter-access
handover proceeds to step 280.
[0053] At step 280, the PCRF2 50 sends an authorization decision to the
GW2 40 or, in the alternative; the GW2 40 may request the authorization
decision from the PCRF2 50. Accordingly, the GW2 40 enforces the policy
decision based on the PCRF2 50 authorization and the IP session may
continue through the new access (i.e., through the GW2 40 and the PCRF2
50).
[0054] FIG. 5 illustrates an inter-access handover via the mobile user
equipment (UE) with access specific policy control functions between an old
gateway and AF/P-CSCF and between a new gateway and AF/P-CSCF, in
accordance with an embodiment of the present invention. Similarly to the
embodiment illustrated in FIG. 3, FIG. 5 illustrates the mobile user
equipment (UE) 100 exchanging information between the GWl 20, the old
Policy Control and Charging Rules Function (PCRFl) 30, the new gateway
(GW2) 40, the new Policy Control and Charging Rules Function (PCRF2)
50, and the Application Function (AF)/Proxy Call Session Control Function
(P-CSCF) 60.
[0055] The description corresponding to steps 100 to 120 described in
FIG. 3 are incorporated herein. From step 120, the handover proceeds to
step 330. At step 330, the mobility signaling is requested from the UE 10 to
the new gateway GW2 40 for the inter-access handover and the GW2 40
transmits information parameters to the UE 10 to support mobility.
[0056] At step 340, in reply to the mobility signaling requested by the UE
10, the GW2 40 transmits the information parameters to the UE 10 for
mobility. Such information parameters may include, for instance, identity
associated with the GW2 40 and/or IP address of the GW2 40. At step 350,
the UE 10 relays or transmits the information parameters to the old gateway
GWl 20. In reply, at step 360, the GWl 20 transmits mobility signaling
parameters to the UE 10 including the IP address of the old PCRFl 30 and
the IP address of the AF/P-CSCF 60.
[0057] At step 370, based on the information parameters (e.g., the IP
address of the GW2 40) the UE 10 transmits to the GW2 40 the mobility
signaling parameters and information parameters which may comprise the
PCRFl 30 IP address and the AF/P-CSCF 60 IP address, and the GW2 40
confirms a handover request. At step 380, the GW2 40 reports the
parameters to the PCRF2 50 to request authorization for the ongoing
session(s) from the PCRF2 50. After step 380, the inter-access handover
proceeds to either step 390 or step 410.
[0058] In one aspect of the present invention, using the IP address of the
AF/P-CSCF 60, at step 390, the PCRF2 50 sends a session parameter request
to the AF/P-CSCF 60. In this instance, the PCRF2 50 may have to make
possible service/subscription related register inquiries to the PCRFl 30 or to
a subscriber data register (not shown) if the service subscription related
information is used for the authorization decision. At step 400, the AF/P-
CSCF 60 sends to the PCRF2 50 session information including possible
service or the subscription related information. The inter-access handover
proceeds to step 430.
[0059] In an alternative, using the IP address of the PCRFl 30, at step
410, the PCRF2 50 would send an authorization parameter request to the
PCRFl 30 and possible service or subscription related data, which the
PCRFl 30 had previously requested from relevant registers, and/or possibly
the current authorization decision from the PCRFl 30. At step 420, the
PCRFl 30 sends authorization parameters and/or subscriber related data
and/or the current authorization decision to the PCRF2 50. The PCSFl may
also provide the information parameters to the AF/P-CSCF 60. The PCRF2
50 would make an authorization decision based on the authorization
parameters or would adapt the authorization decision from the PCRFl 30 of
an existing session(s), taking into account requirements and limitations
specific to the new session(s) or access type. The inter-access handover
proceeds to step 430.
[0060] At step 430, the PCRF2 50 sends an authorization decision to the
GW2 40, i.e., as a push operation. In the alternative, the GW2 40 may
request the authorization decision from the PCRF2 50, i.e. as a pull
operation. The GW2 40 would then enforce the authorization decision.
[0061] FIG. 6 illustrates a direct inter-access handover signaling between
the old gateway, GWl 20, and the new gateway, GW2 40, in accordance
with an embodiment of the present invention. Similarly to the embodiment
illustrated in FIG. 3, FIG. 6 illustrates the mobile user equipment (UE) 100
exchanging information between the GWl 20, the old Policy Control and
Charging Rules Function (PCRFl) 30, the new gateway (GW2) 40, the new
Policy Control and Charging Rules Function (PCRF2) 50, and the
Application Function (AF)/Proxy Call Session Control Function (P-CSCF)
60.
[0062] The description corresponding to steps 100 to 120 described in
FIG. 3 are incorporated herein. From step 120, at step 530, the mobility
signaling is requested from the UE 10 to the new gateway GW2 40 for the
inter-access handover and the GW2 40 transmits the information parameters
to the UE 10 to support mobility. The request from the UE 10 the GW2 40
may contain, in addition to other related parameters, the IP address or
identity information of the old gateway GWl 20.
[0063] At step 540, the GW2 40 transmits an information request to the
GWl 20 including the IP address of the GW2 40. At step 550, in response
to the information request, the GWl 20 transmits an information response to
the GW2 40 including the IP address of the PCRFl 30 and the IP address of
the AF/P-CSCF 60. At step 560, the GW2 40 relays or transmits the
information response to the PCRF2 50.
[0064] In one aspect of the present invention, after step 560, using the IP
address of the AF/P-CSCF 60, at step 570, the PCRF2 50 sends the session
parameter request to the AF/P-CSCF 60. In this instance, the PCRF2 50
may have to make possible service/subscription related register inquiries to
the PCRFl 30 or to a subscriber data register (not shown) if the service
subscription related information is used for the authorization decision. At
step 580, the AF/P-CSCF 60 sends to the PCRF2 50 session information
including possible service or subscription related information. The direct
inter-access handover signaling then proceeds to step 610.
[0065] In an alternative, after step 560, using the IP address of the PCRFl
30, at step 590, the PCRF2 50 would send an authorization parameter
request to the PCRFl 30 and possible service or subscription related data,
which the PCRFl 30 had previously requested from relevant registers,
and/or possibly the current authorization decision from the PCRFl 30. At
step 600, the PCRFl 30 sends the authorization parameters and/or subscriber
related data and/or the current authorization decision to the PCRF2 50. The
PCSFl may also provide the information parameters to the AF/P-CSCF 60.
The PCRF2 50 would make an authorization decision based on the
authorization parameters or would adapt the authorization decision from the
PCRFl 30 of an existing session(s), taking into account requirements and
limitations specific to the new session(s) or access type. The direct inter-
access handover signaling proceeds to step 610.
[0066] At step 610, the PCRF2 50 sends an authorization decision to the
GW2 40, i.e., as a push operation. In the alternative, the GW2 40 may
request the authorization decision from the PCRF2 50, i.e., as a pull
operation. The GW2 40 would then enforce the authorization decision.
[0067] Accordingly, FIGS. 3 and 4 illustrate a handover mechanism in
which the AF obtains the address of the new Policy Control and Charging
Rules Function (PRCF2) and sends session information to the PRCF2 and
FIGS. 5 and 6 illustrate a handover mechanism in which the PCRF2 50
obtains the address from the old Policy Control and Charging Rules
Function (PRCFl) and/or the Application Function AF/P-CSCF 60 and
requests the session information. Accordingly, the present invention offers a
seamless inter-access handover without any interruptions or delays.
Signaling trafficking is minimized that may be required to update the new
control element (i.e., the GW2 40 and the PCRF2 50) with the required
session information.
[0068] In addition, a person of ordinary skill in the art will appreciate that
although the old and the new policy control and charging rules functions are
described and illustrated separate from the access gateway, GWl or GW2, or
the AF/P-CSCF, a person of ordinary skill in the art will appreciate that the
old policy control and charging rules functions and/or the new policy control
and charging rules function may be integrated as part of the access gateway
or the AF/P-CSCF.
[0069] Furthermore, although FIGS. 3 to 6 illustrate an old access
gateway, GWl, and a new access gateway, GW2, a person of ordinary
skilled in the art will appreciate that a single gateway may be provided to
include the structure and functions associated with the old access gateway
and the new access gateway as a single unit. For instance, FIG. 7 illustrates
an inter-access handover via the UE 10 with access specific policy control
functions between a single gateway and AF/P-CSCF, in accordance with an
embodiment of the present invention. The description corresponding to
steps 100 to 120 described in FIG. 3 are incorporated herein. From step
120, the handover proceeds to step 650. At step 650, the UE 10 exchanges
information with a single gateway, GW, 25 for mobility. Specifically; the
UE 10 exchanges the information parameters with the GW 25.
[0070] At step 660, the GW 25 sends an indication/report of the handover
with the information parameters to the old policy control function, PCRFl
30. At step 670, upon processing of the information parameters, the PCRFl
30 requests session information for the ongoing sessions from the AF/P-
CSCF 60 to be sent from the application function AF/P-CSCF 60 to the new
Policy and Charging Rules Function the PCRF2 50 based on the information
parameters. The request would also provide the information parameters to
the AF/P-CSCF 60. The request from the PCRFl 30 may also include
authorization information, e.g. an authorization made previously by the
PCRFl 30 for the session, or session related parameters. The request from
the PCRFl 30 may also include service or subscription related information,
thereby the PCRF2 50 would not need to issue a separate request for this
subscription related information from subscriber registers, thus, saving
processing time. Furthermore, if the IP address of the PCRF2 50 is in the
request from the PCRFl 30, the AF/P-CSCF 60 uses the IP address of the
PCRF2 50 as a contact address to the PCRF2 50. On the other hand, if the
IP address of the PCRF2 50 is not included in the request but a parameter is
included in the request indicative of a new type of handover access, and,
consequently, indicative of a need to use a new PCRF to continue with the
HANDOVER session, the AF/P-CSCF 60 determines the IP address of the
new PCRF from the parameter and the IP address of the UE 10 or other
identity information available from the UE 10. After step 670, the inter-
access handover proceeds to either step 680 or step 685.
[0071] In one aspect of the present invention, at step 68O 5 the AF/P-CSCF
60 pushes the authorization information or session information and the
possible service or the subscription related information to the PCRF2 50.
The inter-access handover proceeds to step 1090.
[0072] In an alternative, at step 685, the PCRFl 30 sends an authorization
message including an authorization decision or session information and/or
subscriber data directly to the PCRF2 50 because the PCRFl 30 has the
information and the IP address of the PCRF2 50. In this instance, the
AF/CSCF 60 updates the PCRF related information, the session which is
now managed by the PCRF2 50 instead of the PCRFl 30, when receiving
the reporting message (step 670) from the PCRFl 30. The inter-access
handover proceeds to step 690.
[0073] At step 690, the PCRF2 50 sends an authorization decision to the
GW 25 or, in the alternative, the GW 25 may request the authorization
decision from the PCRF2 50. Accordingly, the GW 25 enforces the policy
decision based on the PCRF2 50 authorization and the IP session may
continue through the new access (i.e., through the PCRF2 50).
[0074] In accordance with an embodiment of the present invention, FIG. 8
illustrates an inter-access handover method including, at step 700,
exchanging a handover mobility signal between a user equipment (UE) and
a new gateway. At step 710, the method transmits information parameters to
an old gateway in response to the handover mobility signal. At step 720, the
method transmits the information parameters from the old gateway to an old
policy control function. At step 730, the method requests session
information of an ongoing session from an application function by the old
policy control function. At step 740, the inter-access handover method
transmits, based on the information parameters, the session information,
possible service or subscription related information, and/or an IP address of
the new gateway from the application function or the old policy control
function to a new policy control function. At step 750, the method transmits
an authorization decision from the new policy control function to the new
gateway to continue the session through the new gateway and the new policy
control function.
[0075] In accordance with an embodiment of the present invention, FIG. 9
illustrates an alternative embodiment of an inter-access handover method
including, at step 800, transmitting a handover mobility signal from a user
equipment (UE) to a new gateway. At step 810, the method transmits
information parameters from the new gateway through the UE to an old
gateway in response to the handover mobility signal. At step 820, the
method transmits, based, on the information parameters, mobility signaling
parameters from the old gateway through the UE to the new gateway, the
mobility signaling parameters including an IP address of an old policy
control function and an IP address of an application function. At step 830,
the method reports the mobility signaling parameters from the new gateway
to a new policy control function to request authorization for at least one
ongoing session. At step 840, the method transmits an authorization
decision from the new policy control function to the new gateway to
continue the at least one ongoing session through the new gateway and the
new policy control function.
[0076] In accordance with an embodiment of the present invention, FIG.
10 illustrates a direct inter-access handover method including, at step 900,
transmitting a handover mobility signal from a user equipment (UE) to a
new gateway. At step 910, the method transmits information parameters
from the new gateway to the UE in response to the handover mobility signal.
At step 920, the method transmits an information request from the new
gateway to an old gateway. At step 930, the method transmits an
information response from the old gateway to the new gateway, the
information response including an IP address of an old policy control
function and an IP address of an application function. At step 940, the
method transmits, based on the information response, mobility signaling
parameters from the new gateway to a new policy control function to request
authorization for at least one ongoing session. At step 950, the method
transmits an authorization decision from the new policy control function to
the new gateway to continue the at least one ongoing session through the
new gateway and the new policy control function.
[0077] It is to be understood that in the embodiment of the present
invention, the steps are performed in the sequence and manner as shown
although the order of some steps and the like may be changed without
departing from the spirit and scope of the present invention.
[0078] The present invention may be applicable, although not limited, to
packet switched services in a mobile communication system. Such services
include packet switched communication between a mobile client terminal of
an end-user and an application server. The mobile communication system
includes a radio network such as for example a WCDMA, CDMA2000,
Wireless LAN or GPRS network in which the mobile client terminal resides.
The system may also include a wired access such as for example an xDSL.
[0079] With respect to the present invention, network devices may be any
device that utilizes network data, and can include switches, routers, bridges,
gateways or servers. In addition, while the term data has been used in the
description of the present invention, the invention has import to many types
of network data. For purposes of this invention, the term data includes
packet, cell, frame, datagram, bridge protocol data unit packet, packet data
and any equivalents thereof.
[0080] The many features and advantages of the invention are apparent
from the detailed specification and, thus, it is intended by the appended
claims to cover all such features and advantages of the invention which fall
within the true spirit and scope of the invention. Further, since numerous
modifications and changes will readily occur to those skilled in the art, it is
not desired to limit the invention to the exact construction and step
illustrated and described, and accordingly all suitable modifications and
equivalents may be resorted to, falling within the scope of the invention.