U.S. patent application number 13/213753 was filed with the patent office on 2011-12-08 for recovery procedures between subscriber registers in a telecommunications network.
Invention is credited to Maria Concepcion Garcia Alonso, Daniel Mateos, Santiago Munoz Munoz.
Application Number | 20110300862 13/213753 |
Document ID | / |
Family ID | 42133618 |
Filed Date | 2011-12-08 |
United States Patent
Application |
20110300862 |
Kind Code |
A1 |
Munoz Munoz; Santiago ; et
al. |
December 8, 2011 |
RECOVERY PROCEDURES BETWEEN SUBSCRIBER REGISTERS IN A
TELECOMMUNICATIONS NETWORK
Abstract
The present invention is aimed to provide subscriber registers
of a mobile network with higher performance and memory capacity
whilst keeping recovery procedures, such as redundancy and
restoration procedures, up to reasonable levels and measurements of
network performance, signalling load and response time. The present
invention provides for a new clustered architecture for subscriber
registers, wherein each subscriber register comprises a number of
processing blades, each processing blade handling a reduced number
of subscribers, and wherein more processing blades can be added
without affecting other components in the subscriber register.
Failures and unavailability are expected to often occur on a
processing blade basis, so that recovery procedures may be carried
out for a reduced number of subscribers, thus being completed with
lower signalling load and response times. To this end, the present
invention also provides for a new method of updating subscriber
data between two subscriber registers where at least one follows
the clustered architecture.
Inventors: |
Munoz Munoz; Santiago;
(Madrid, ES) ; Garcia Alonso; Maria Concepcion;
(Majadahonda - Madrid, ES) ; Mateos; Daniel;
(Gatefe (Madrid), ES) |
Family ID: |
42133618 |
Appl. No.: |
13/213753 |
Filed: |
August 19, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12518632 |
Jun 10, 2009 |
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PCT/EP2006/069621 |
Dec 12, 2006 |
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13213753 |
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Current U.S.
Class: |
455/433 |
Current CPC
Class: |
Y02B 30/54 20130101;
Y02B 30/545 20130101; A47C 21/044 20130101; A41D 13/0025 20130101;
F24F 1/0007 20130101; A47G 9/086 20130101; E04H 15/12 20130101;
A47G 9/0215 20130101 |
Class at
Publication: |
455/433 |
International
Class: |
H04W 8/02 20090101
H04W008/02 |
Claims
1. A clustered subscriber register holding subscriber data for
subscribers in a mobile network, the subscriber data comprising
subscription data and location data for each subscriber, the
clustered subscriber register comprising: an input unit arranged
for receiving location data for a subscriber from a seizing node in
the mobile network; a plurality of processing blades, each
processing blade handling a number of subscribers and comprising: a
storage arranged for storing subscriber data for the subscriber,
and a processor arranged for processing a course of actions to be
taken for the subscriber depending on subscriber data for the
subscriber; a distributor for determining the processing blade
currently handling the subscriber; and an output unit arranged for
submitting a subscriber identity for the subscriber, an identifier
of the clustered subscriber register and an identifier of the
processing blade handling the subscriber towards a secondary
subscriber register in the mobile network, wherein the input unit
is arranged for receiving from the secondary subscriber register an
upgraded operation to process a course of actions for the
subscriber, the upgraded operation including the subscriber
identity for the subscriber and the identifier of the processing
blade handling the subscriber.
2. The clustered subscriber register of claim 1, wherein the output
unit is arranged for submitting, along with the subscriber identity
for the subscriber, the identifier of the clustered subscriber
register and the identifier of the processing blade, a set of
subscriber data for the subscriber towards the secondary subscriber
register in the mobile network.
3. The clustered subscriber register of claim 1, acting as a
Visitor Location Register (VLR) holding subscriber data for
subscribers roaming in a VLR area of the mobile network, the input
unit being arranged for receiving location data for the subscriber
from a Mobile Switching Centre (MSC) currently serving the
subscriber, the output unit being arranged for submitting to a Home
Location Register (HLR) which holds subscriber data for subscribers
of the mobile network, the subscriber identity for the subscriber,
the identifier of the Visitor Location Register and the identifier
of the processing blade handling the subscriber therein.
4. The clustered subscriber register of claim 2, acting as a Home
Location Register (HLR) holding subscriber data for subscribers of
the mobile network, the input unit being arranged for receiving
location data for the subscriber from a Visitor Location Register
(VLR), which is serving the subscriber and holds subscriber data
for subscribers roaming in a VLR area of the mobile network, the
output unit being arranged for submitting to a redundant Home
Location Register (R-HLR), which holds redundant subscriber data
for subscribers of the mobile network, the subscriber identity and
the set of subscriber data for the subscriber, the identifier of
the Home Location Register and the identifier of the processing
blade handling the subscriber therein.
5. The clustered subscriber register of claim 4, further comprising
a replicator for coordinating with the redundant Home Location
Register a redundancy procedure for sending subscriber data for
subscribers handled in a processing blade identified by a given
identifier.
6. The clustered subscriber register of claim 5, wherein the
replicator further comprises a state-transition machine operating
on a processing blade basis to determine the status of the
redundancy procedure on course for each processing blade.
7. The clustered subscriber register of claim 2, acting as a Home
Location Register holding subscriber data for subscribers of the
mobile network, the input unit being arranged for receiving
location data for the subscriber from a Visitor Location Register,
winch is serving the subscriber and holds subscriber data for
subscribers roaming in a VLR area of the mobile network, the output
unit being arranged for submitting to the Visitor Location Register
the subscriber identity and the set of subscriber data for the
subscriber, the identifier of the Home Location Register and the
identifier of the processing blade handling the subscriber
therein.
8. The clustered subscriber register or claim 2, acting as a Home
Subscriber Server (HSS) holding subscriber data for subscribers of
an IP Multimedia Subsystem (IMS) in the mobile network, the input
unit being arranged for receiving location data for the subscriber
from a Serving Call Session Control Function server (S-CSCF), which
is assigned for serving the subscriber in the IMS, and the output
unit being arranged for submitting to said Serving Call Session
Control Function server the subscriber identity and the set of
subscriber data for the subscriber, the identifier of the Home
Subscriber Server and the identifier of the processing blade
handling the subscriber.
9. The clustered subscriber register of claim 7, further comprising
a restorer arranged for submitting, after having recovered from a
failure affecting a processing blade, a reset indication to
secondary subscriber registers holding subscriber data for those
subscribers handled by the recovered blade, the reset indication
including the identifier of the clustered subscriber register and
the identifier of the recovered processing blade.
10. A secondary subscriber register arranged for holding subscriber
data for subscribers in a mobile network, the subscriber data
comprising subscription data and location data for each subscriber,
the secondary subscriber register comprising: an input unit
arranged for receiving from a clustered subscriber register, which
holds subscriber data her a subscriber in the mobile network, a
subscriber identity for the subscriber, an identifier of the
clustered subscriber register, and an identifier of a processing
blade handling the subscriber at the clustered subscriber register;
a storage arranged for storing subscriber data, the subscriber
identity, the identifier of the clustered subscriber register and
the identifier of the processing blade for the subscriber; a
processor arranged for processing a course of actions to be taken
for the subscriber depending on the received subscriber data; and
an output unit arranged for submitting towards the clustered
subscriber register an upgraded operation to process a course of
actions tor the subscriber, the upgraded operation including the
subscriber identity for the subscriber and the identifier of the
processing blade handling the subscriber.
11. The secondary subscriber register of claim 10, wherein the
input unit is arranged for receiving a set of subscriber data for
the subscriber, along with the subscriber identity for the
subscriber, the identifier of the clustered subscriber register and
the identifier of the processing blade, from the clustered
subscriber register in the mobile network.
12. The secondary subscriber register of claim 10, acting as a Home
Location Register (HLR) holding subscriber data for subscribers of
the mobile network, the input unit being arranged for receiving
from a Visitor Location Register (VLR), which is currently serving
the subscriber and holds subscriber data for subscribers roaming in
a VLR area of the mobile network, the subscriber identity for the
subscriber, the identifier of the Visitor Location Register and the
identifier of the processing blade handling the subscriber.
13. The secondary subscriber register of claim 11, acting as a
redundant Home Location Register (R-HLR) holding redundant
subscriber data for subscribers of the mobile network, the input
unit being arranged for receiving from a clustered Home Location
Register, which holds subscriber data for subscribers of the mobile
network, the subscriber identity and the set of subscriber data for
the subscriber, the identifier of the Home Location Register and
the identifier of the processing blade handling the subscriber.
14. The secondary subscriber register of claim 13, further
comprising a replicator for coordinating with the clustered Home
Location Register a redundancy procedure for receiving subscriber
data for those subscribers handled in a processing blade identified
by a given identifier.
15. The secondary subscriber register of claim 14, wherein the
replicator further comprises a state-transition machine operating
on a processing blade basis to determine the status of the
redundancy procedure on course for each processing blade.
16. The secondary subscriber register of claim 11, acting as a
Visitor Location Register currently serving the subscriber and
holding subscriber data for subscribers roaming in a VLR area of
the mobile network, further comprising an output unit arranged for
submitting location data for the subscriber towards a Home Location
Register, which holds subscriber data for subscribers of the mobile
network, and wherein the input unit is arranged for receiving from
the Home Location Register the subscriber identity and the set of
subscriber data for the subscriber, the identifier of the Home
Location Register and the identifier of the processing blade
handling the subscriber.
17. The secondary subscriber register of claim 11, acting as a
Serving Call Session Control Function server (S-CSCF) serving the
subscriber in an IP Multimedia Subsystem (IMS) of the mobile
network, further comprising an output unit arranged for submitting
location data for the subscriber towards a Home Subscriber Server
(HSS), which holds subscriber data for subscribers of IMS in the
mobile network, and the input unit being arranged for receiving
from the HSS the subscriber identity and the set of subscriber data
for the subscriber, the identifier of the Home Subscriber Server
and the identifier of the processing blade handling the
subscriber.
18. The secondary subscriber register of claim 16, further
comprising a restorer arranged for receiving a reset indication
from the clustered subscriber register, the reset indication
including the identifier of the clustered subscriber register and
an identifier of a processing blade recovered after failure; and
arranged for initiating a restoration procedure for ail the
subscribers in the secondary subscriber register with the received
identifier of a processing blade.
19. A method of updating subscriber data between a clustered
subscriber register and a secondary subscriber register, both
holding subscriber data for subscribers in a mobile network, the
subscriber data comprising subscription data and location data, the
method comprising the steps of: receiving at the clustered
subscriber register location data for a subscriber from a serving
node in the mobile network; determining at a distributor of the
clustered subscriber register a processing blade currently handling
the subscriber among a plurality of processing blades, each
processing blade handling a number of subscribers and including a
storage and a processor; processing at the processor included in
the processing blade, a course of actions to be taken for the
subscriber depending on the subscriber data; submitting from the
clustered subscriber register towards the secondary subscriber
register a subscriber identity for the subscriber, an identifier of
the clustered subscriber register, and an identifier of the
processing blade handling the subscriber at the clustered
subscriber register; and receiving at the clustered subscriber
register from the secondary subscriber register an ungraded
operation to process a course of actions for the subscriber, the
upgraded operation including the subscriber identity for the
subscriber and the identifier of the processing blade handling the
subscriber.
20. The method of claim 19, wherein the step of submitting from the
clustered subscriber register towards the secondary subscriber
register a subscriber identity for the subscriber, an identifier of
the clustered subscriber register, and an identifier of the
processing blade includes a step of obtaining from the storage in
the processing blade a set of subscriber data far the subscriber,
and a step of submitting the set of subscriber data for the
subscriber.
21. The method of claim 19, wherein the step of receiving location
data for the subscriber takes place at a Visitor Location Register
(VLR) holding subscriber data for subscribers roaming in a VLR area
of the mobile network, the location data for the subscriber being
submitted from a Mobile Switching Centre (MSC) currently serving
the subscriber, and wherein the step of submitting takes place at
the Visitor Location Register towards a Home Location Register
(HLR), which holds subscriber data for subscribers of the mobile
network, the submission including the subscriber identity for the
subscriber, the identifier of the Visitor Location Register and the
identifier of the processing blade handling the subscriber
therein.
22. The method of claim 20, wherein the step of receiving location
data for the subscriber takes place at a HLR holding subscriber
data for subscribers of the mobile network, the location data for
the subscriber being submitted from a Visitor Location Register,
which is serving the subscriber and holding subscriber data for
subscribers roaming in a VLR area of the mobile network, the step
of submitting taking place at the HLR towards a redundant Home
Location Register (R-HLR), which holds redundant subscriber data
for subscribers of the mobile network, the submission including the
subscriber identity and the set of subscriber data for the
subscriber, the identifier of the Home Location Register and the
identifier of the processing blade handling the subscriber
therein.
23. The method of claim 22, further comprising a step of
coordinating between the Home Location Register and the R-HLR a
redundancy procedure for sending subscriber data for those
subscribers handled in a processing blade identified by a given
identifier.
24. The method of claim 22, further comprising a step of operating
a state-transition machine on a processing blade basis to determine
the status of the redundancy procedure on course for each
processing blade.
25. The method of claim 20, wherein the step of receiving location
data for the subscriber takes place at a Home Location Register
holding subscriber data for subscribers of the mobile network, the
location data for the subscriber being submitted from a Visitor
Location Register, which is serving the subscriber and holding
subscriber data for subscribers roaming in a VLR area of the mobile
network, the step of submitting taking place at the HLR towards the
Visitor Location Register, the submission including the subscriber
identity and the set of subscriber data for the subscriber, the
identifier of the Home Location Register and the identifier of the
processing blade handling the subscriber therein.
26. The method of claim 20, wherein the step of receiving location
data for the subscriber takes place at a Home Subscriber Server
(HSS) holding subscriber data for subscribers of an IP Multimedia
Subsystem (IMS) in the mobile network, the location data for the
subscriber being submitted from a Serving Call Session Control
Function server (S-CSCF), winch is assigned for serving the
subscriber in the IMS, the step of submitting taking place at the
Home Subscriber Server towards said Serving Call Session Control
Function server, the submission including the subscriber identity
and the set of subscriber data for the subscriber, the identifier
of the Home Subscriber Server and the identifier of the processing
blade handling the subscriber therein.
27. The method of claim 25, further comprising a step of
submitting, after having recovered from a failure affecting a
processing blade, a reset indication from the Home Location
Register to those Visitor Location Registers holding subscriber
data for those subscribers handled by the recovered blade, the
reset indication including the identifier of the Home Location
Register and the identifier of the recovered processing blade.
28. The method of claim 26, further comprising a step of
submitting, after having recovered from a failure affecting a
processing blade, a reset indication from the Home Subscriber
Server towards those Serving Call Session Control Function servers
holding subscriber data for those subscribers handled by the
recovered blade, the reset indication including the identifier of
the Home Subscriber Server and the identifier of the recovered
processing blade.
Description
TECHNICAL FIELD
[0001] The present invention generally relates to enhanced recovery
procedures to be carried out between subscriber registers,
subscriber databases, or subscriber serving nodes in a
telecommunication network. In particular, the invention relates to
subscriber registers, subscriber databases, or subscriber serving
nodes in a mobile network to allow a faster recovery after failures
therein and. more specifically, to minimize the failure situation
by detecting partial failures involving only a set of subscribers
and by acting on these partial failures.
BACKGROUND
[0002] The high penetration of mobile networks worldwide is now an
irrefutable fact and the number of subscribers, as well as the
traffic load through the networks, is expected to continue growing
as more and more attractive services and achievements are available
to users of the mobile networks.
[0003] As the number of subscribers grow up for mobile networks,
even of a different generation, such as the GSM for a legacy
2.sup.nd generation network or the IP Multimedia Subsystem "IMS"
under a 3.sup.rd generation network, network operators are
continuously demanding more performance and memory capacity, whilst
maintaining profitability of their business, for those network
nodes supporting huge amounts of subscribers and network data.
[0004] For instance, a Home Location Register "HLR" in charge of
subscriber data, including subscription data, service data and
location data for subscribers of a 2.sup.nd generation mobile
network, and a Visitor Location Register "VLR" holding subscriber
data for subscribers roaming in a VLR area of the 2.sup.nd
generation mobile network, are candidate nodes to be demanded with
as high performance and memory capacity as possible to support huge
amounts of subscriber data. In particular, the VLR may be provided
and considered alone, or in combination with a Mobile Switching
Centre "MSC" serving the subscriber and providing, among others,
call-related functions. In operation, the VLR receives from the MSC
a message indicating a location updating for a subscriber roaming
into a VLR area, the message including and identifier of the MSC,
and submits towards the HLR a corresponding location updating
message, the message now including an identifier of the VLR. The
HLR receiving such location updating message, stores the received
VLR identifier as location data for the subscriber and returns back
to the VLR the own HLR identifier which is stored in the VLR for
any further communication. Thus, both HLR having subscriber data
for all the subscribers of a mobile network, and VLR having
subscriber data for all the subscribers roaming in areas controlled
by said VLR, which might be almost all subscribers in crowd
population areas, are expected to be provided with even higher
performance and memory capacity.
[0005] Likewise, a Home Subscriber Server "HSS" holding subscriber
data, including subscription, service and location data for
subscribers of the IMS in a 3.sup.rd generation network, and a
Serving Call Session Control Function "S-CSCF", which is a node
assigned for serving the subscriber in the IMS, may be comparable
candidate nodes to be demanded with as high performance and memory
capacity as possible to support huge amounts of subscriber data. In
operation, a subscriber accesses the IMS via a Proxy Call Session
Control Function "P-CSCF", from where a corresponding registration
message is submitted towards an interrogating Call Session Control
Function "I-CSCF". The I-CSCF queries the HSS in order to obtain
capabilities required for assigning a serving node for serving the
subscriber. Once such capabilities are received from the HSS, the
I-CSCF selects and assigns an S-CSCF suitable for serving the
subscriber, and submits the registration message towards said
S-CSCF. The S-CSCF then submits a message towards the HSS
indicating to be assigned for serving the user, the indication
including an identifier of said S-CSCF, an obtains from the HSS a
user profile, including the subscriber data for the subscriber,
along with an identifier of the HSS. Thus, both the HSS having
subscriber data for all the subscribers of an IMS network, and the
S-CSCF having subscriber data for all the served subscribers in the
IMS network, which might still be a significant number of
subscribers, are expected to be provided with high performance and
memory capacity.
[0006] In particular, the location data is traditionally
interpreted as an identifier of the S-CSCF serving the subscriber
for the HSS in the IMS; as an identifier of the VLR where the
subscriber is roaming for the HLR in the 2.sup.nd generation mobile
network; and as an identifier of the MSC currently serving the
subscriber for the VLR in the 2.sup.nd generation mobile
network.
[0007] Apart from the above candidate nodes to be provided with
higher performance and capacity: HLR, VLR, HSS, S-CSCF, other
network nodes provided for redundancy purposes may be clear
candidates as well. For example, a redundant Home Location Register
"R-HLR" holding redundant subscriber data for subscribers in one or
more primary Home location Registers of the 2.sup.nd generation
mobile network, is a network node possibly requiring the highest
performance and memory capacity, especially, where configured to
serve more than one HLR. for redundancy purposes. Generally
speaking, a mobile network may be configured with more than one HLR
or HSS, as the case may be. In a first configuration, each HLR or
HSS may have a first memory portion for primary subscribers handled
therein, and a second portion for redundant subscribers handled in
another HLR or HSS, so that such network node may be regarded as a
primary HLR or HSS for own subscribers and as a R-HLR or R-HSS for
redundant subscribers handled in a corresponding primary HLR or
HSS. In a second configuration, each primary HLR or HSS includes
all its own subscribers and there is provided a corresponding mated
node, namely an R-HLR or R-HSS, including redundant data for all
the subscribers from the former. In a still third configuration,
there is a unique R-HLR or R-HSS handling redundant subscribers
from a number of primary HLR's or HSS's as the case may be.
[0008] Amongst other recovery procedures in currently existing
2.sup.nd or 3.sup.rd generation mobile networks, a so-called
Redundancy Procedure in HLR or HSS, as the case may be, assumes
that a primary HLR or HSS is configured with subscriber data for
its own subscribers, whereas an R-HLR or R-HSS is configured with
subscriber data for redundant subscribers, which are in fact
handled in a primary HLR or HSS. In the following, a redundancy
procedure is explained with reference to an HLR of a 2.sup.nd
generation mobile network whilst it may be applicable as well for
those skilled in the art to a 3.sup.rd generation mobile network
and, more particularly, to an HSS of an IMS network. However, in
other implementations the assumption may be that only the primary
HLR is configured with subscriber data for the primary subscribers
whereas the R-HLR obtains all the redundant subscriber data once
entering into normal operation.
[0009] In general and during normal operation, traffic messages are
routed by the network to the HLR where a given subscriber is
defined as primary. However, each HLR may accept operations from
the network for any subscriber defined therein. Where a
non-permanent subscriber data is changed in the primary HLR in
charge of corresponding subscriber, as a consequence of any
subscriber activities such as a change in the subscriber location
data, said data change is sent from the primary HLR towards the
R-HLR, wherein the changed non-permanent subscriber data is
updated. In a situation where the primary HLR fails, or becomes
unavailable to the network, the R-HLR starts handling traffic for
all subscribers in the failing primary HLR. Afterwards, once the
failing primary HLR has recovered from the failure and resumes
work, the non-permanent subscriber data for a huge number of
subscribers may be not up-to-date since, depending on how long the
failure lasts, a huge amount of subscriber activities took place
with corresponding changes on subscriber data. In this end, the
recovering primary HLR keeps disconnected from the network until
having been updated with information up-to-date from the R-HLR.
Once updated, the primary HLR may enter into operation and the
R-HLR disconnected from the network.
[0010] This so-called Redundancy Procedure, as other recovery
procedures in currently existing 2.sup.nd or 3.sup.rd generation
mobile networks, becomes a quite overloading procedure where
demands are put by network operators to provide network nodes
supporting huge amounts of subscribers and subscriber data and thus
presenting a higher performance and memory capacity, whilst
maintaining low prices. More specifically, the provision of network
nodes such as HLR, VLR, HSS, S-CSCF, and R-HLR with higher
performance and memory capacity represents a challenging drawback
for suppliers wanting to keep the overall network performance,
signalling load and response times up to reasonable levels and
measurements.
[0011] Apart from the so-called Redundancy Procedure explained
above, other recovery procedures such as a Restoration procedure
between an HLR and a VLR of a 2.sup.nd generation mobile network
may also penalize the overall network performance, signalling load
and response times up to reasonable levels and measurements.
[0012] Where a HLR in a 2.sup.nd generation mobile network, or a
HSS in an IMS network, has recovered from a failure situation and
comprises subscriber data which can not be considered up-to-date
for a substantial number subscribers, and with or without support
of the above Redundancy procedure, such HLR or HSS requires the
updating of most significant subscriber data for all the
subscribers as there is no clue of what subscriber data may be
trustable or not, and for what subscribers. In this respect, the
subscriber location data is one among the most significant
subscriber data for this purpose and may be wrong where addressing
a previous serving node, namely a previous MSC, VLR or S-CSCF, not
currently serving the subscriber due to a newer roaming area
involving a different MSC or VLR, or a re-assignation of a new
S-CSCF to handle service capabilities not supported by the previous
S-CSCF and required for a new service invoked by the subscriber. In
the following, a restoration procedure is explained with reference
to an HLR of a 2.sup.nd generation mobile network whilst it may be
applicable as well for those skilled in the art to a 3.sup.rd
generation mobile network and, more particularly, to an HSS of an
IMS network.
[0013] A so-called restoration procedure may start once a failing
HLR has recovered from a failure and resumes work, and
non-permanent subscriber data, such as the location data, for a
huge number of subscribers may be not up-to-date. Such recovered
HLR, following a `best effort` approach, sends a reset indication
towards all the known VLR's where own subscribers are marked to be
roaming. Those VLR's receiving such reset indication, which
includes an identifier of the HLR having recovered from a failure,
search for subscribers marked with said HLR identifier and
disconnect such subscribers by withdrawing them from the VLR areas
where they are roaming in order to force a new location updating
that allows the recovered HLR to get appropriate location data for
such subscribers.
[0014] As for the redundancy procedure and other recovery
procedures, the restoration procedure becomes a quite overloading
procedure where demands are put by network operators to provide
network nodes supporting huge amounts of subscribers and subscriber
data and thus presenting a higher performance and memory capacity,
whilst maintaining low prices. In view of this so-called
restoration procedure, the provision of network nodes such as HLR,
VLR, HSS, S-CSCF, and R-HLR with higher performance and memory
capacity represents a challenging drawback for suppliers wanting to
keep the overall network performance, signalling load and response
times up to reasonable levels and measurements.
SUMMARY
[0015] It is an object of the invention to obviate or, at least,
minimize some of the above drawbacks, and to provide network nodes
for mobile network operators, such as HLR, VLR, HSS, S-CSCF, and
R-HLR with higher performance and memory capacity whilst still
keeping the overall network performance, signalling load and
response times up to reasonable levels and measurements.
[0016] To this end, there is provided in accordance with a first
aspect of the invention a clustered subscriber register for holding
subscriber data for subscribers in a mobile network, wherein the
subscriber data comprise subscription data as well as location data
for each subscriber. This clustered subscriber register includes:
[0017] an input unit arranged for receiving location data for a
subscriber from a serving node in the mobile network; [0018] a
plurality of processing blades, each processing blade handling a
number of subscribers and comprising: a storage arranged for
storing subscriber data for the subscriber, and a processor
arranged for processing a course of actions to be taken for the
subscriber depending on subscriber data for the subscriber; [0019]
a distributor for determining the processing blade currently
handling the subscriber; and [0020] an output unit arranged for
submitting a subscriber identity for the subscriber, an identifier
of the clustered subscriber register, and an identifier of the
processing blade handling the subscriber towards a secondary
subscriber register in the mobile network.
[0021] This clustered architecture for a subscriber register,
wherein each processing blade is in charge of a number of
subscribers, allows for a profitable scalability where more
processing blades can be added without substantially affecting the
rest of components in the clustered subscriber register. In
addition, failures and unavailability are expected to more
frequently occur on a processing blade basis, rather than for the
whole clustered subscriber register, so that proper actions can be
taken for one or a reduced number of processing blades, instead of
for the whole clustered subscriber register. Bearing in mind that
each processing blade just handles a number of subscribers, the
recovery procedures can be carried out for an expectedly smaller
number of subscribers, thus being completed with lower signalling
load and response times.
[0022] In particular, this clustered subscriber register may be
useable as a VLR and, in such a case, the input unit is arranged
for receiving the location data for the subscriber from an MSC
currently serving the subscriber, whereas the output unit is
arranged for submitting towards a HLR the subscriber identity for
the subscriber, the identifier of the VLR and the identifier of the
processing blade handling the subscriber therein. In other words,
the clustered subscriber register may act as a VLR receiving
location data from the MSC, and submitting its own VLR identifier
and its processing blade identifier as location data for the
subscriber towards the secondary subscriber register, that is,
towards the HLR. Regarding the HLR, it may be a non-clustered HLR
behaving as a secondary subscriber register adapted to inter-work
with a clustered VLR, or it may be a clustered HLR behaving in
accordance with this clustered subscriber register as well.
[0023] This clustered subscriber register may be implemented in
accordance with embodiments of the invention so that the output
unit is further arranged for submitting a set of subscriber data
along with the subscriber identity for the subscriber, the
identifier of the clustered subscriber register and the identifier
of the processing blade, towards the secondary subscriber register
in the mobile network. This is particularly interesting for using
this clustered subscriber register as a HLR of a 2.sup.nd
generation mobile network and, in such a case, the input unit is
arranged for receiving location data for the subscriber from a VLR
currently serving the subscriber; as well as for using this
clustered subscriber register as a HSS of an IMS in a 3.sup.rd
generation mobile network and, in such a case, the input unit is
arranged for receiving location data for the subscriber from a
S-CSCF currently assigned for serving the subscriber.
[0024] Where the clustered subscriber register acts as a HLR, the
output unit may be arranged for submitting towards an R-HLR, which
behaves as the secondary subscriber register for redundancy
purposes, the subscriber identity and the set of subscriber data
for the subscriber, the identifier of the HLR and the identifier of
the processing blade handling the subscriber in said HLR. This
clustered subscriber register acting as a HLR towards a secondary
subscriber register acting as a R-HLR may further comprise a
replicator for coordinating with the R-HLR a redundancy procedure
for sending subscriber data for those subscribers handled in a
processing blade identified by a given identifier. Moreover, the
replicator may further comprise a state-transition machine
operating on a processing blade basis to determine the status of
the redundancy procedure on course for each processing blade thus
helping to keep the overall network performance, signalling load
and response times up to reasonable levels and measurements where
recovery procedures can be carried out on a processing blade
basis.
[0025] Where the clustered subscriber register acts as a HLR, the
output unit may be arranged as well for submitting towards a VLR,
which behaves as the secondary subscriber register for holding
subscriber data for subscribers roaming in a VLR area of the mobile
network, the subscriber identity and the set of subscriber data for
the subscriber, the identifier of the HLR and the identifier of the
processing blade handling the subscriber in said HLR. This
clustered subscriber register, acting as a HLR towards a secondary
subscriber register acting as a VLR, may further comprise a
restorer arranged for submitting, after having recovered from a
failure affecting a processing blade, a reset indication towards
those VLRs holding subscriber data for those subscribers handled by
the recovered blade, the reset indication including the identifier
of the clustered subscriber register and the identifier of the
recovered processing blade. This more selective reset allows a
faster restoration procedure thus helping to keep the overall
network performance, signalling load and response limes up to
reasonable levels and measurements where recovery procedures can be
carried out on a processing blade basis.
[0026] Where the clustered subscriber register acts as a HSS, the
output unit may be arranged for submitting towards the S-CSCF,
which behaves as the secondary subscriber register for serving the
subscriber in the IMS, the subscriber identity and the set of
subscriber data for the subscriber, the identifier of the Home
Subscriber Server and the identifier of the processing blade
handling the subscriber. This clustered subscriber register, acting
as a HSS towards a secondary subscriber register acting as a
S-CSCF, may also further comprise a restorer arranged for
submitting, after having recovered from a failure affecting a
processing blade, a reset indication towards those S-CSCFs holding
subscriber data for those subscribers handled by the recovered
blade, the reset indication including the identifier of the
clustered subscriber register and the identifier of the recovered
processing blade.
[0027] Furthermore, the clustered subscriber register, whatever use
is given, may be implemented so that the input unit is arranged for
receiving any upgraded operation to process a course of actions for
the subscriber, wherein this upgraded operation includes the
subscriber identity for the subscriber and the identifier of the
processing blade handling the subscriber.
[0028] In accordance with a second aspect of the invention, there
is provided a secondary subscriber register inter-working with the
above clustered subscriber register for holding subscriber data for
subscribers in the mobile network, the subscriber data comprising
subscription data and location data for each subscriber. This
secondary subscriber register comprises: [0029] an input unit
arranged for receiving from the clustered subscriber register,
which holds subscriber data for a subscriber in the mobile network,
a subscriber identity for the subscriber, an identifier of the
clustered subscriber register, and an identifier of a processing
blade handling the subscriber at the clustered subscriber register;
[0030] a storage arranged for storing subscriber data and the
subscriber identity for the subscriber, the identifier of the
clustered subscriber register and the identifier of the processing
blade for the subscriber therein; and [0031] a processor arranged
for processing a course of actions to be taken for the subscriber
depending on the received subscriber data.
[0032] This secondary subscriber register may further comprise an
output unit arranged for submitting towards the clustered
subscriber register any upgraded operation to process a course of
actions for the subscriber, wherein each upgraded operation
includes the subscriber identity for the subscriber and the
identifier of the processing blade handling the subscriber at the
clustered subscriber register.
[0033] In particular, where the above clustered subscriber register
may be useable as a VLR, this secondary subscriber register may be
useable as a HLR and, in such a case, the input unit is arranged
for receiving from the VLR the subscriber identity for the
subscriber, the identifier of the VLR, and the identifier of the
processing blade handling the subscriber as location data for said
subscriber.
[0034] This secondary subscriber register may be implemented in
accordance with embodiments of the invention so that the input unit
is arranged for receiving a set of subscriber data for the
subscriber, along with the subscriber identity for the subscriber,
the identifier of the clustered subscriber register and the
identifier of the processing blade, from the clustered subscriber
register in the mobile network. Aligned with corresponding
embodiments for the clustered subscriber register, this input unit
arranged for receiving a set of subscriber data for the subscriber
is particularly interesting for using this secondary subscriber
register as an R-HLR, as a VLR, or as an S-CSCF.
[0035] Where this secondary subscriber register is acting as an
R-HLR, the input unit is arranged for receiving from a clustered
HLR the subscriber identity and the set of subscriber data for the
subscriber, the identifier of said HLR and the identifier of the
processing blade handling the subscriber at said HLR. This
secondary subscriber register acting as an R-HLR may further
comprise a replicator for coordinating with the clustered HLR a
redundancy procedure for receiving subscriber data for those
subscribers handled in a processing blade identified by a given
identifier. Moreover, this replicator may further comprise a
state-transition machine operating on a processing blade basis to
determine the status of the redundancy procedure on course for each
processing blade thus helping to keep the overall network
performance, signalling load and response times up to reasonable
levels and measurements where recovery procedures can be carried
out on a processing blade basis by coordinated clustered and
secondary subscriber registers provided in accordance with several
aspects of the invention
[0036] Where this secondary subscriber register is acting as a VLR,
the input unit is arranged for receiving from a clustered HLR the
subscriber identity and the set of subscriber data for the
subscriber, the identifier of said HLR and the identifier of the
processing blade handling the subscriber at said HLR. Moreover,
this secondary subscriber register acting as a VLR further
comprises an output unit arranged for submitting location data for
the subscriber towards the clustered HLR, this location data
comprising an identifier of the subscriber and an identifier of the
VLR. Furthermore, this secondary subscriber register acting as a
VLR may further comprise a restorer arranged for receiving a reset
indication from the clustered HLR, the reset indication including
the identifier of the clustered HLR and an identifier of a
processing blade recovered after failure. Still further, the
restorer may be arranged for initiating a restoration procedure for
all the subscribers with the received identifier of the processing
blade in this secondary subscriber register acting as a VLR.
[0037] Where this secondary subscriber register is acting as an
S-CSCF, the input unit is arranged for receiving from a clustered
HSS the subscriber identity and the set of subscriber data for the
subscriber preferably in the form of a user profile, the identifier
of said HSS and the identifier of the processing blade handling the
subscriber at said HSS. Moreover, this secondary subscriber
register acting as an S-CSCF further comprises an output unit
arranged for submitting location data for the subscriber towards
the clustered HSS, this location data comprising an identifier of
the subscriber and an identifier of the S-CSCF. Furthermore, this
secondary subscriber register acting as an S-CSCF may further
comprise a restorer arranged for receiving a reset indication from
the clustered HSS, the reset indication including the identifier of
the clustered HSS and an identifier of a processing blade recovered
after failure. Still further, the restorer may be arranged for
initiating a restoration procedure for all the subscribers with the
received identifier of the processing blade in this secondary
subscriber register acting as an S-CSCF.
[0038] The above clustered subscriber register may be thus used in
cooperation with the above secondary register so that the clustered
subscriber register incorporates a number of processing blades and
provides an identifier of the processing blade handling a given
subscriber, whereas the secondary subscriber register is arranged
for receiving this identifier of a processing blade handling the
given subscriber, and is arranged for applying recovery procedures
on a processing blade basis.
[0039] These clustered and secondary subscriber registers are
enabled in accordance with a third aspect of the invention to carry
out a method of updating subscriber data between said clustered
subscriber register and said secondary subscriber register, both
holding subscriber data for subscribers in a mobile network, the
subscriber data comprising subscription data and location data.
This method comprises the steps of: [0040] receiving at the
clustered subscriber register location data for a subscriber from a
serving node in the mobile network; [0041] determining at a
distributor of the clustered subscriber register a processing blade
currently handling the subscriber, among a plurality of processing
blades, each processing blade handling a number of subscribers and
including a storage and a processor; [0042] processing at the
processor included in the processing blade a course of actions to
be taken for the subscriber depending on the subscriber data; and
[0043] submitting from the clustered subscriber register towards
the secondary subscriber register a subscriber identity for the
subscriber, an identifier of the clustered subscriber register, and
an identifier of the processing blade handling the subscriber at
the clustered subscriber register.
[0044] In a first embodiment of the invention, the step of
receiving location data for the subscriber and the step of
submitting identifiers in this method may take place in a clustered
subscriber register acting as a VLR. In this embodiment, an MSC is
the serving node where the location data is received from, whereas
a HLR is the secondary subscriber register where the subscriber
identity for the subscriber, the identifier of the VLR and the
identifier of the processing blade are submitted to.
[0045] The above method is particularly advantageous where the step
of submitting the subscriber identity, the identifier of the
clustered subscriber register, and the identifier of the processing
blade from the clustered subscriber register towards the secondary
subscriber register includes a step of obtaining from the storage
included in the processing blade a set of subscriber data for the
subscriber, and a step of submitting the set of subscriber data for
the subscriber.
[0046] In a second embodiment of the invention, the step of
receiving location data for the subscriber and the step of
submitting the subscriber identity and the set of subscriber data
for the subscriber, the identifier of the clustered subscriber
register, and the identifier of the processing blade in this method
may take place in a clustered subscriber register acting as a HLR.
In this second embodiment, a VLR is the serving node where the
location data is received from, whereas an R-HLR is the secondary
subscriber register where the subscriber identity and the set of
subscriber data for the subscriber, the identifier of the HLR and
the identifier of the processing blade are submitted to. Moreover,
the method may further comprise for this second embodiment a step
of coordinating between the HLR and the R-HLR a redundancy
procedure for sending subscriber data for those subscribers handled
in a processing blade identified by a given identifier.
Furthermore, in order to determine the status of the redundancy
procedure on course for each processing blade, the method may also
comprise a step of operating a state-transition machine on a
processing blade basis.
[0047] In a third embodiment of the invention, the step of
receiving location data for the subscriber and the step of
submitting the subscriber identity and the set of subscriber data
for the subscriber, the identifier of the clustered subscriber
register, and the identifier of the processing blade in this method
may take place in a clustered subscriber register acting as a HLR.
In this third embodiment, a VLR is also the serving node where the
location data is received from, whereas said VLR is the secondary
subscriber register where the subscriber identity and the set of
subscriber data for the subscriber, the identifier of the HLR and
the identifier of the processing blade are submitted to. Moreover,
the method may further comprise for this third embodiment a step of
submitting, after having recovered from a failure affecting a
processing blade, a reset indication from the HLR towards those
VLRs holding subscriber data for those subscribers handled by the
recovered blade, the reset indication including the identifier of
the HLR and the identifier of the recovered processing blade.
[0048] In a fourth embodiment of the invention, the step of
receiving location data for the subscriber and the step of
submitting the subscriber identity and the set of subscriber data
for the subscriber, the identifier of the clustered subscriber
register, and the identifier of the processing blade in this method
may take place in a clustered subscriber register acting as a HSS.
In this fourth embodiment, an S-CSCF is the serving node where the
location data is received from, whereas said S-CSCF is the
secondary subscriber register where the subscriber identity and the
set of subscriber data for the subscriber, the identifier of the
HSS and the identifier of the processing blade are submitted to. As
for the above third embodiment, the method may further comprise for
this fourth embodiment a step of submitting, after having recovered
from a failure affecting a processing blade, a reset indication
from the HSS towards those S-CSCF holding subscriber data for those
subscribers handled by the recovered blade, the reset indication
including the identifier of the HSS and the identifier of the
recovered processing blade.
[0049] Commonly applicable to the above embodiments, the method may
further comprise a step of receiving any upgraded operation to
process a course of actions for the subscriber, wherein the
upgraded operation includes the subscriber identity for the
subscriber and the identifier of the processing blade handling the
subscriber in order to more efficiently reach subscriber data and
identify actions to be done for said subscriber.
[0050] In accordance with a fourth aspect of the invention, there
is provided a computer program, loadable into an internal memory of
a computer with input and output units as well as with a processing
unit, the computer program comprising executable software adapted
to carry out at least some of the above method steps when running
in the computer. In particular, the executable software of this
computer program may be recorded in a carrier readable in a
computer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The features, objects and advantages of the invention will
become apparent by reading this description in conjunction with the
accompanying drawings, in which:
[0052] FIG. 1 is a sequence diagram illustrating an embodiment of a
method for updating the subscriber location between a Visitor
Location Register and a Home Location Register, wherein the Home
Location Register is a clustered subscriber register in accordance
with the invention.
[0053] FIG. 2 is a sequence diagram illustrating a method of
restoration from the Home Location Register towards a plurality of
Visitor Location Registers known to said Home Location Register, in
accordance with an embodiment of the invention.
[0054] FIG. 3 is a sequence diagram illustrating an embodiment of a
method for updating the subscriber location between a Mobile
Switching Centre and a Visitor Location Register and between the
Visitor Location Register and a Home Location Register, wherein the
Visitor Location Register is a clustered subscriber register in
accordance with the invention.
[0055] FIG. 4 is a basic block structure presenting the structural
elements that a clustered subscriber register comprises in
accordance with an embodiment of the invention where acting as a
Home Location Register.
[0056] FIG. 5 is a basic block diagram illustrating a scenario
where clustered and subscriber registers as well as method of the
invention may be applied in a 2.sup.nd generation mobile
network.
[0057] FIG. 6 is a basic block diagram illustrating a scenario
where clustered and subscriber registers as well as method of the
invention may be applied for an IMS in a 3.sup.rd generation mobile
network.
[0058] FIG. 7 is a basic block structure presenting the structural
elements that a clustered subscriber register comprises in
accordance with an embodiment of the invention where acting as a
Visitor Location Register.
[0059] FIG. 8 is a sequence diagram illustrating an embodiment of a
method for registering a subscriber in an IMS network, said method
including a method of updating the subscriber location between a
Serving Call Session Control Function and a Home Subscriber Server,
wherein the Home Subscriber Server is a clustered subscriber
register in accordance with the invention.
[0060] FIG. 9 is a basic block structure presenting the structural
elements that a clustered subscriber register comprises in
accordance with an embodiment of the invention where acting as a
Home Subscriber Server.
[0061] FIG. 10 is a basic block structure presenting the structural
elements that a secondary subscriber register comprises in
accordance with several embodiments of the invention where acting
as a Visitor Location Register, as a Home Subscriber Server, as a
Serving Call Session Control Function, as a Home Subscriber Server,
or as a redundant Home Location Register.
[0062] FIG. 11a-11d is a sequence diagram illustrating an
embodiment of a method for carrying out a redundancy procedure
between a clustered subscriber register acting as a Home Location
Register and a secondary subscriber register acting as a redundant
Home Location Register, the method showing how a replica of
non-permanent subscriber data is created in the redundant Home
Location Register whilst the primary Home Location Register is
active, how the redundant Home Location Register handles
subscribers whilst a partial failure occurs in the primary Home
Location Register, and how the primary Home Location Register
becomes active after recovering from the partial failure, and once
a replica of changed non-permanent subscriber data is created in
the primary Home Location Register from the redundant Home Location
Register.
DETAILED DESCRIPTION
[0063] The following describes some preferred embodiments for a
method of updating subscriber data between a clustered subscriber
register and a secondary subscriber register, both holding
subscriber data for subscribers in a mobile network, wherein the
subscriber data comprises subscription data and location data.
Apart from this method, the following describes exemplary
embodiments of said clustered subscriber register and said
secondary subscriber register in terms of its respective structural
elements to carry out said method.
[0064] In a first embodiment of the invention illustrated in FIG. 3
there is provided a method of updating subscriber data between a
clustered subscriber register 40 acting as a VLR, namely a
clustered VLR "C-VLR", and a secondary subscriber register acting
as a HLR. This method may preferably apply in a scenario as
basically illustrated in FIG. 5 wherein a subscriber 1 attaches via
a radio interface a 2.sup.nd generation mobile network through a
base station not shown for the sake of simplicity, and reaches a
Base Station Centre "BSC" 94 connected with an MSC 92 receiving the
subscriber attach.
[0065] This method illustrated in FIG. 3 starts with a step S-121
of receiving at the clustered VLR (C-VLR) 40 location data for the
subscriber 1 from the MSC 92, which is the serving node currently
serving the subscriber in the mobile network.
[0066] To this end, as illustrated in FIG. 7, the C-VLR 40 includes
an input unit 45 arranged for receiving said location data for the
subscriber from the MSC 92 in the mobile network. Since this C-VLR
comprises a plurality of processing blades 41-43, a particular
processing blade 42 must be determined for handling this
subscriber. This particular processing blade 42, as each processing
blade 41-43, handles a number of subscribers and comprises: a
storage 422 arranged for storing subscriber data for the subscriber
1, and a processor 421 arranged for processing a course of actions
to be taken for the subscriber depending on subscriber data for
said subscriber. To this end, the C-VLR 40 includes a distributor
44, the so-called visitor distribution module "VDM" in this instant
specification, for determining the processing blade 42 currently
handling the subscriber. In particular, this distributor may
include a central processor 441 for carrying out common routines
for all the processing blades as well as for controlling the
availability status for each processing blade. Then, the input unit
45 internally passes a location updating message received with
location data for the subscriber to the distributor 44, which is
the internal entity receiving the location data during this step
S-121.
[0067] The sequence of actions illustrated in FIG. 3 thus continues
with a step S-122 of determining at the distributor 44 of the C-VLR
the processing blade 42 for handling the subscriber, and internally
passing the location updating message received with location data
for the subscriber to said processing blade 42. Then, the
processing blade receiving such location updating message,
processes and stores the new location, namely an identifier of the
MSC 92 currently serving the subscriber, and submits in step S-123
towards the secondary subscriber register 30, which in the present
embodiment is a HLR holding subscriber data for subscribers of the
mobile network, a subscriber identity for the subscriber, an
identifier of the C-VLR, and an identifier of the processing blade
handling the subscriber at the C-VLR.
[0068] To this end, as illustrated in FIG. 7, the C-VLR, comprises
an output unit 46 an output unit arranged for submitting the
subscriber identity for the subscriber, the identifier of the
C-VLR, and the identifier of the processing blade handling the
subscriber towards a secondary subscriber register, in this case
the HLR, in the mobile network.
[0069] On the other hand, the secondary subscriber register 30
illustrated in FIG. 10, which in this first embodiment is a HLR of
a 2.sup.nd mobile network, comprises an input unit 25 arranged for
receiving from the C-VLR the subscriber identity for the
subscriber, the identifier of the C-VLR, and the identifier of the
processing blade handling the subscriber at the C-VLR; a storage 21
arranged for storing the subscriber data 212 and the subscriber
identity 211 for the subscriber, the identifier 213 of C-VLR and
the identifier 214 of the processing blade for the subscriber
therein; and a processor 24 arranged for processing a course of
actions to be taken for the subscriber depending on the received
subscriber data. In particular, the method described in this first
embodiment may further include a step S-124 of storing at the HLR
the location data, namely the identifier of the C-VLR 40 and the
identifier of the processing blade 42, for the subscriber.
[0070] This method allows any further action triggered for this
subscriber 1 towards the C-VLR to include the identifier of the
processing blade in order to more efficiently reach subscriber data
and identify actions to be done for said subscriber. For example,
the method described in this first embodiment may further include a
step S-125 of submitting from the HLR towards the C-VLR a set of
subscriber data for the subscriber along with an identifier of the
HLR and the identifier of the processing blade 42 handling the
subscriber in the C-VLR. To this end, the secondary subscriber
register acting as the HLR 30 also comprises an output unit 26
arranged for submitting towards the clustered subscriber register,
which is now the C-VLR 40. an upgraded operation to process a
course of actions for the subscriber, wherein each upgraded
operation includes the subscriber identity for the subscriber and
the identifier of the processing blade handling the subscriber at
the clustered subscriber register.
[0071] In a second embodiment of the invention partially
illustrated in FIG. 1 and more specifically illustrated in FIG.
11b-11c as part of an exemplary redundancy procedure, there is
provided a method of updating subscriber data between a clustered
subscriber register 10 acting as a HLR, namely a clustered HLR
"C-HLR", and a secondary subscriber register acting as an R-HLR.
This method may preferably apply in a scenario as basically
illustrated in FIG. 5 wherein a subscriber 1 attaches via a radio
interface a 2.sup.nd generation mobile network through a base
station not shown for the sake of simplicity, reaches a Base
Station Centre "BSC" 94 connected with an MSC 92 receiving the
subscriber attach, and submitting an update location message
towards a VLR 20 in charge of the VLR area where the MSC belongs
to. Frequently, the VLR and the MSC are provided as a combination
in a unique network node and are commonly referred to as an
MSC/VLR.
[0072] The method under this second embodiment, as illustrated in
FIG. 1 and FIG. 11b, starts with a step S-101 of receiving at the
clustered HLR (C-HLR) 10 location data for the subscriber 1 from
the VLR (or MSC/VLR as the case might be) 20, which is the serving
node currently serving the subscriber in the mobile network.
[0073] To this end, as illustrated in FIG. 4, the C-HLR 10 includes
an input unit 15 arranged for receiving said location data for the
subscriber from the VLR 20 in the mobile network. Since this C-HLR
comprises a plurality of processing blades 11-13, a particular
processing blade 11 must be determined for handling this
subscriber. This particular processing blade 11, as each processing
blade 11-13, handles a number of subscribers and comprises: a
storage 112 arranged for storing subscriber data for the subscriber
1, and a processor 111 arranged for processing a course of actions
to be taken for the subscriber depending on subscriber data for
said subscriber. To this end, the C-HLR 10 includes a distributor
14, the so-called home distribution module "HDM" in this instant
specification, for determining the processing blade 11 currently
handling the subscriber. In particular, this distributor may
include a central processor 141 for carrying out common routines
for all the processing blades as well as for controlling the
availability status for each processing blade. Then, the input unit
15 internally passes the location updating message received with
location data for the subscriber to the distributor 14, which is
the internal entity receiving the location data during this step
S-101.
[0074] As for the previous embodiment, the sequence of actions
illustrated in FIG. 1 and FIG. 11b thus continues with a step S-102
of determining at the distributor 14 of the C-HLR the processing
blade 11 for handling the subscriber, and internally passing the
location updating message received with location data for the
subscriber to said processing blade 11. Then, the processing blade
receiving such location updating message, processes and stores the
new location, namely an identifier of the VLR 20 currently serving
the subscriber and, as illustrated in FIG. 11c, submits in step
S-166 towards a secondary subscriber register 90, which in the
present embodiment is an R-HLR holding redundant subscriber data
for subscribers of the mobile network, a subscriber identity for
the subscriber, an identifier of the C-HLR, and an identifier of
the processing blade 11 handling the subscriber at the C-HLR.
[0075] To this end, as illustrated in FIG. 4, the C-HLR, comprises
an output unit 16 arranged for submitting the subscriber identity
for the subscriber, the identifier of the C-HLR, and the identifier
of the processing blade 11 handling the subscriber towards a
secondary subscriber register, in this case the R-HLR 90, in the
mobile network.
[0076] On the other hand, the secondary subscriber register 90
illustrated in FIG. 10, which in this second embodiment is an
R-HLR, comprises an input unit 25 arranged for receiving from the
C-HLR 10 the subscriber identity for the subscriber, the identifier
of the C-HLR, and the identifier of the processing blade 11
handling the subscriber at the C-HLR; a storage 21 arranged for
storing the subscriber data 212 and the subscriber identity 211 for
the subscriber, the identifier 213 of C-HLR and the identifier 214
of the processing blade for the subscriber therein; and a processor
24 arranged for processing a course of actions to be taken for the
subscriber depending on the received subscriber data.
[0077] The method described hereinbefore, as well as the structural
elements that form the clustered and the secondary subscriber
registers, especially in respect of the above second embodiment,
allow recovery procedures such as the so-called redundancy
procedure to be carried out for network nodes such as HLR, VLR,
HSS, S-CSCF, and R-HLR with higher performance and memory capacity
whilst keeping the overall network performance, signalling toad and
response times up to reasonable levels and measurements.
[0078] In the following an exemplary redundancy procedure between a
clustered HLR "C-HLR" and a redundant HLR "R-HLR" as illustrated in
FIG. 11a to FIG. 11d. The assumption in this exemplary method is
that both C-HLR and R-HLR have been configured with the same
permanent subscriber data for those so-called primary subscribers
in the C-HLR and for those corresponding redundant subscribers in
the R-HLR. The non-permanent subscriber data, such as the
subscriber location or other service indicators, may be either
configured with default values or marked unknown until having
adopted a particularly significant value. Once both C-HLR and R-HLR
are operating in the mobile network, they both may indicate to each
with a certain periodicity whether they are in an active status or
not.
[0079] The exemplary redundancy procedure illustrated in FIG. 11a
starts with a coordination between the C-HLR 10 and the R-HLR 90 of
the redundancy procedure for sending subscriber data for those
subscribers handled in each processing blade. Such coordination may
be initiated by the C-HLR or by the R-HLR. The illustrated
exemplary procedure starts when the R-HLR 90 submits during step
S-151 a redundancy control "RC" message indicating its own
identifier of secondary subscriber register, namely the identifier
of the R-HLR, along with an indication of being in an active
status, towards the clustered subscriber register, namely the C-HLR
10.
[0080] To this end, the input unit 15 in the C-HLR illustrated in
FIG. 4 cooperates with a replicator 17 to start an internal
redundancy control amongst the different processing blades 11-13
that the C-HLR consists of. For the sake of simplicity, the input
unit is not illustrated in the sequence diagram of FIG. 11a to 11b.
In an alternative embodiment not illustrated in any drawing, the
central processor 141 may include the functions of the replicator
17 so that the latter, as an isolated entity, may be
unnecessary.
[0081] Again with reference to the method illustrated in FIG. 11a,
the replicator 17 receiving the redundancy control "RC" message in
step S-151, indicating an active status of the R-HLR 90, sends
during steps S-152, S-154, S-156 towards each processing blade
11-13 an internal RC message asking for its individual status. Such
query is answered from each processing blade during steps S-153,
S-155, S-157 indicating its own identifier of processing blade and
its own status, which in this case is an active status from all the
processing blades. The replicator 17 in cooperation with the output
unit 16, the latter not shown for the sake of simplicity, sends in
step S-158 a corresponding redundancy control "RC" message,
indicating the own identifier of the C-HLR 10 along with an
indication of being in an active status, towards the R-HLR 90. The
sending of this redundancy control indicating an active status may
be assumed as an implicit trigger for checking the needs for a
replica updating, or might start a time gap before triggering such
checking.
[0082] In principle, a replica updating is needed whenever any
non-permanent subscriber data has changed for a subscriber handled
in a processing blade. The replica updating is canned out only for
changed data in order to keep up-to-date the contents in the R-HLR,
just in case the R-HLR has to enter into operation following a
certain failure in the C-HLR. As illustrated in FIG. 11a and FIG.
11b, the replicator 17 queries the processing blades 11-13 during
steps S-159, S-161, S-165 whether a replica updating is needed or
not. In this exemplary method, the processing blade 13 answers in
step S-160 that the replica updating is not needed towards the
replicator which marks, this situation. This particular processing
blade 13 is not further shown in the following sequence of actions
illustrated in FIG. 11b to FIG. 11d since it does not participate
thereof, and in order to facilitate the drawing of further
interesting network nodes or actions involving the present
nodes.
[0083] As receiving the replica updating query during step S-161 in
the processing blade 12 illustrated in FIG. 11b, it is found
therein that the replica in the R-HLR must be updated for a number
of subscriber data. To this end, as illustrated in FIG. 4, the
internal processor 121 cooperates with the internal storage 122 in
the processing blade 12 to compile a list of subscriber data to be
updated in the replica handled in the R-HLR 90.
[0084] Regarding the replica updating, and even though changeable
non-permanent subscriber data are candidates to be updated, one may
assume that permanent subscriber data, which are changeable only by
the operator and likely with provisioning or configuration means,
may also be included in a replica updating thus making unnecessary
the operator intervention in both C-VLR and R-HLR.
[0085] Once the processing blade 12 has compiled the list of
subscriber data to be updated, it sends in step S-162 such
subscriber data along with an identifier of the C-HLR and an
identifier of the processing blade 12 towards the R-HLR 90. Such
list is used to update the replica in the R-HLR, and an acknowledge
message is returned during step S-163 from the R-HLR to the C-HLR
including the identifier of the processing blade 12.
[0086] To this end, and bearing in mind that the secondary
subscriber register, as illustrated in FIG. 10 and claimed by the
present invention, is acting as the R-HLR in accordance with this
second embodiment, said R-HLR comprises an input unit 25 arranged
for receiving from the C-HLR 10 the subscriber identity and the set
of subscriber data for each subscriber, the identifier of the C-HLR
10 and the identifier of the processing blade 12 handling the
subscribers; and a storage 21 arranged for storing on a subscriber
basis the subscriber identity 211 and the set of subscriber data
212 for each subscriber, the identifier 213 of the C-HLR 10 and the
identifier 214 of the processing blade 12 handling the subscribers.
In addition, the secondary subscriber register acting as R-HLR may
also comprise a replicator 27 for coordinating with the C-HLR 10
the redundancy procedure for receiving subscriber data 212 for
those subscribers handled in a processing blade 12 identified by a
given identifier 214. As previously commented for the structural
elements that the C-HLR may comprise, the replicator 27 may be
superfluous in the secondary subscriber register acting as R-HLR if
the processor 24 is arranged to carry out a corresponding
redundancy control and functionality.
[0087] Upon receipt in the processing blade 12 in step S-163 of the
acknowledge indicating the replica has been updated in the R-HLR
90, the processing blade indicates the completion of such updating
in step S-164 to the replicator 17. This indication may be
advantageous for operating a state-transition machine 171-1 in the
replicator to mark a corresponding status for such processing blade
12. To this end, the C-HLR illustrated in FIG. 4 may also include a
state-transition machine 171-1 included in, or in cooperation with,
the replicator 17 or the distributor 14 or the central processor
141 included therein.
[0088] Back to the sequence of actions illustrate in FIG. 11b and
following ones, one may assume that actions modifying the
non-permanent subscriber data may occur at any time, even during a
redundancy procedure. In order to illustrate such a situation, the
sequence of actions in FIG. 11b continues with the reception of a
location updating for a subscriber at the C-HLR 10 during a step
S-101 from a VLR 20 currently serving the subscriber. As previously
discussed above when introducing the method of updating subscriber
data between a clustered subscriber register and a secondary
subscriber register, both holding subscriber data for subscribers
in a mobile network, under this second embodiment, such updating of
location data is received in the distributor 14 in cooperation with
the input unit 15 of the C-HLR, and internally forwarded towards
the processing blade 11 handling the subscriber. The new location
data are processed by the local processor 111 and stored in storage
112 in the processing blade 11, and a successful result is returned
back to the VLR 20, either directly during step S-108 as
illustrated in FIG. 11b, or indirectly through the distributor 14
during steps S-106 and S-107 as shown in FIG. 1. This particular
VLR 20 and the distributor 14 are not further shown in the
following sequence of actions illustrated in FIG. 11c and FIG. 11d
since they do not participate thereof, and in order to facilitate
the drawing of further interesting actions involving the present
nodes.
[0089] At this stage different alternatives may be implemented
without substantially departing from the main provisions of the
invention. The updating of location data for a subscriber in the
C-HLR 10 may trigger a replica updating towards the R-HLR 90 in a
first alternative not shown in any drawing, or may be simply be
marked as `replica pending` so that a further replica updating
query from the replicator 17 may trigger such replica updating for
the new location data towards the R-HLR as illustrated in a second
alternative shown in FIG. 11b.
[0090] In this exemplary method, where the above second alternative
is followed, the replicator 17 internally sends during step S-165
the query about needs for replica updating towards the processing
blade 11. This processing blade 11, or rather its processor 111,
detects that there is a replica updating and compiles a list of
subscriber data to be submitted towards the R-HLR 90. This list may
include, not only the latest location data updated for one
subscriber, but all the subscriber data modified since a last
replica updating took place.
[0091] Regarding the replica updating, and depending on the total
amount of subscriber data to be submitted, the processing blade
might need one or more signalling messages such as a so-called
Update Subscriber Data "USD". Where the submission must be
segmented into several USDs for submitting all the subscriber data,
the identifier of the C-HLR 10 and the identifier of the processing
blade 11 is included in each USD along with the subscriber data
fitting the signalling message.
[0092] As illustrated in FIG. 11c, and once the list of subscriber
data to be updated is ready, the processing blade 11 in cooperation
with the output unit 16 sends during step S-166 one or more USDs
with an amount of subscriber data, the identifier of the C-HLR 10
and the identifier of the processing blade 11 and advantageously
with one end-of-transmission indicator to advice there is no
further USD to submit. Once the replica has been updated in the
R-HLR 90, an acknowledge is returned back to the processing blade
11 during step S-167, and the processing blade receiving such
acknowledge sends during step S-168 towards the replicator 17 an
indication of having completed the replica updating. As for a
previous processing blade, this indication may be advantageous for
operating a state-transition machine 171-1 in the replicator 17 to
mark a corresponding status for such processing blade 11.
[0093] Regarding the coordination of redundancy control and status
between C-HLR and R-HLR, they do not necessarily have to be
synchronized. Each one may have its own supervision time to
indicate to each other its own status.
[0094] In this exemplary method, as illustrated in FIG. 11c, the
replicator starts a new redundancy control process towards each
processing blade 11-13. To this end, an internal RC message asking
for its individual status is submitted towards the processing blade
12 in step S-169 and answered during step S-170 from the processing
blade 12 indicating its own identifier of processing blade and its
own status, which in this case is active. This particular
processing blade 12 is not further shown in the following sequence
of actions illustrated in FIG. 11d since it docs not participate
thereof, and in order to facilitate the drawing of further
interesting actions involving the present nodes.
[0095] The process new redundancy control process continues as
illustrated in FIG. 11c by sending from the replicator 17 during
step S-171 an internal RC message asking for its individual towards
the processing blade 11. At this stage, this processing blade 11
may have suffered a failure so that it is not able to answer such
message. After a reasonable time gap, likely configurable at the
replicator 17, or at the central processor 141, the replicator 17
may assume the failure, and may inform about it during step S-173
towards the R-HLR 90, indicating the identifier of the C-HLR and
the identifier of the failing processing blade 11.
[0096] This information about the failing processing blade 11 at
the C-HLR 10 is understood by the R-HLR as an implicit indication
to be ready to accept signalling traffic for subscribers marked
with such identifier of processing blade in its local storage
214.
[0097] The exemplary method continues as illustrated in FIG. 11d
with the replicator 17 triggering the switching of routing tables
during step S-174 so that signalling messages addressing the
failing processing blade in the C-HLR are forwarded towards the
R-HLR. In a preferred alternative solution for this embodiment, the
routing tables are included in the distributor 14, so that the
distributor may identify the processing blade in charge of a given
subscriber and, as detecting such subscriber is handled in a
failing processing blade, may forward such signalling message
towards the R-HLR. In another alternative solution, the routing
tables remain in lower protocol layers and are configured on a
processing blade basis, so that upon failure in a processing blade
basis, said lower protocol layers are informed and may switch the
tables and inspect signalling messages for determining whether a
forwarding towards the R-HLR should take place or not. This second
alternative seems to be less efficient than the previous one though
may be more backwards compatible than the first one.
[0098] One the routing tables have been switched, the R-HLR 90 is
ready in step S-175 for handling subscribers previously in charge
of the failing processing blade, and thus continues until the
failing processing blade recovers and is operative again.
[0099] As illustrated in FIG. 11d, once the previously failing
processing blade 11 is active again, it sends towards the
replicator 17 during step S-176 an RC message indicating its
identifier of processing blade as well as its recovering status.
The replicator 17 forwards the RC message indicating the recovering
status along with the identifier of the C-HLR and the identifier of
the recovering processing blade 11 during step S-177 towards the
R-HLR 90.
[0100] Depending on how long the failure lasted, a number of
subscriber data might have changed whilst the corresponding
subscribers were handled by the R-HLR. Upon recovery of the
processing blade 11 in the C-HLR, the R-HLR may need to update the
former with the replica contents in its current values. To this
end, the R-HLR 90 prepares a list with the changed subscriber data,
mainly non-permanent subscriber data but also permanent subscriber
data changed by the operator if the failure lasted quite a long
time. Then, the R-HLR submits during step S-178 those subscriber
data that need to be updated in the recovering processing blade 11
of the C-HLR, along with an identifier of the C-HLR and an
identifier of the recovering processing blade 11. As before, one or
more signalling USD messages may be required to this end, each USD
including the identifier of the C-HLR and the identifier of the
recovering processing blade 11.
[0101] Once the changed subscriber data have been updated in the
recovering processing blade, a successful acknowledge is returned
during step S-179 from the recovering processing blade 11 to the
R-HLR 90. Eventually, the R-HLR may send during step S-180 towards
the replicator 17 an indication of having completed the replica
updating. As for a previous processing blade, this indication may
be advantageously used for operating again the state-transition
machine 171-1 in the replicator 17 to mark a corresponding active
status for such processing blade 11. This indication may be
understood at the replicator 17 as an implicit indication that the
recovering processing blade 11 has recovered and is now in an
active status again. Then, the replicator 17 switches back the
routing tables during step S-181 so that signalling messages
currently addressing the R-HLR are internally forwarded to the
recovered processing blade 11 in the C-HLR. As commented before, in
the preferred alternative solution for this embodiment, the routing
tables are included in the distributor 14, whereas in another
alternative solution, the routing tables remain in lower protocol
layers. After having switched back the routing tables, the
recovered processing blade 11, now in active status takes over in
step S-182 its own subscribers again.
[0102] At this stage, the interesting pan of a redundancy procedure
for the purpose of the present invention does not require further
explanation, but stating that the redundancy control to mutually
check the active status between both C-HLR and R-HLR continues as
previously explained, as well as the internal redundancy control to
check the active status of the processing blades 11-13 in the
C-HLR.
[0103] Nevertheless, after having concluded a recovery of a
processing blade within the above redundancy procedure, and
depending on different implementation alternatives, there may be a
need for a so-called restoration procedure. As exemplary commented
above, whilst some subscribers were temporarily served by the R-HLR
due to a failure in the processing blade primary intended for
handling said subscribers, there might have been a number of
location updating from different VLRs for a number of subscribers.
In this situation, the said VLRs might have got the identifier of
the R-HLR presently handling such subscribers. After the recovery
and switching back of routing tables, the identifier of the HLR
handling the subscriber stored in each VLR might be the identifier
of the R-HLR instead of being the identifier of the C-HLR. The
restoration procedure is an advantageous procedure to ensure this
situation is properly solved and will be further explained in
detail after having discussed a third embodiment of the invention
following this.
[0104] In a third embodiment of the invention illustrated in FIG. 1
and partially anticipated when discussing the second embodiment
illustrated in FIG. 11b-11c, there is provided a method of updating
subscriber data between a clustered subscriber register 10 acting
as a HLR, namely a clustered HLR "C-HLR", and a secondary
subscriber register acting as a VLR. This method, as for the second
embodiment, may preferably apply in the scenario basically
illustrated in FIG. 5 wherein a subscriber 1 attaches via a radio
interface a 2.sup.nd generation mobile network through a base
station not shown for the sake of simplicity, the subscriber
reaches a BSC 94 connected with an MSC 92 receiving the subscriber
attach, and submitting an update location message towards a VLR 20
in charge of the VLR area where the MSC belongs to. Frequently, the
VLR and the MSC are provided as a combination in a unique network
node and are commonly referred to as an MSC/VLR.
[0105] The method in this third embodiment, as illustrated in FIG.
1 and partially in FIG. 11b, starts with a step S-101 of receiving
at the C-HLR 10 location data for the subscriber 1 from the VLR (or
MSC/VLR as the case might be) 20, which is the serving node
currently serving the subscriber in the mobile network.
[0106] To this end, as already commented for the second embodiment
and as illustrated in FIG. 4, the C-HLR 10 includes an input unit
15 arranged for receiving said location data for the subscriber
from the VLR 20 in the mobile network. Since this C-HLR comprises a
plurality of processing blades 11-13, a particular processing blade
11 must be determined for handling this subscriber. This particular
processing blade 11, as each processing blade 11-13, handles a
number of subscribers and comprises: storage 112 arranged for
storing subscriber data for the subscriber 1, and a processor 111
arranged for processing a course of actions to be taken for the
subscriber depending on subscriber data for said subscriber. To
this end, the C-HLR 10 includes a distributor 14, the so-called HDM
in this instant specification, for determining the processing blade
11 currently handling the subscriber. In particular, this
distributor may include a central processor 141 for carrying out
common routines for all the processing blades as well as for
controlling the availability status for each processing blade.
Then, the input unit 15 internally passes the location updating
message received with location data for the subscriber to the
distributor 14, which is the internal entity receiving the location
data during this step S-101.
[0107] On the other hand, as illustrated in FIG. 10, the secondary
subscriber register acting as a VLR comprises an output unit 26
arranged for submitting location data for the subscriber towards
the C-HLR 10, this location data including an identifier of the
subscriber 1 and an identifier of the VLR 20. For the purpose of
the present invention a subscriber identity and an identifier of a
subscriber may be interpreted as equivalent terms, even if nor
having always the same value, or if replaced at a clustered or
secondary register by another subscriber identity or
identifier.
[0108] As for the second embodiment, the sequence of actions
illustrated in FIG. 1 and FIG. 11b thus continues for this third
embodiment with a step S-102 of determining at the distributor 14
of the C-HLR the processing blade 11 for handling the subscriber,
and internally passing the location updating message received with
location data for the subscriber to said processing blade 11.
[0109] Then, as shown in FIG. 1, the processing blade 11 receiving
such location updating message at the C-HLR, processes and stores
the new location, namely the identifier of the VLR 20 currently
serving the subscriber, and submits in step S-103 towards the
secondary subscriber register 20, which in this third embodiment is
said VLR 20, a subscriber identity for the subscriber, an
identifier of the C-HLR, and an identifier of the processing blade
11 handling the subscriber at the C-HLR. The submission in the
above step S-103 of this method also includes, for this third
embodiment, a set of subscriber data along with the subscriber
identity for the subscriber, the identifier of the C-HLR, and the
identifier of the processing blade 11, and a so-called Insert
Subscriber Data "ISD" message may be used for this purpose.
[0110] To this end, as illustrated in FIG. 4, the C-HLR comprises
an output unit 16 arranged for submitting the subscriber identity
and the set of subscriber data for the subscriber 1, the identifier
of the C-HLR, and the identifier of the processing blade 11
handling the subscriber towards a secondary subscriber register,
which in this case is the VLR 20, in the mobile network. On the
other hand, the secondary subscriber register 20 illustrated in
FIG. 10, which in this third embodiment is the VLR 20, comprises an
input unit 25 arranged for receiving from the C-HLR 10 the
subscriber identity and subscriber data for the subscriber, the
identifier of the C-HLR, and the identifier of the processing blade
11 handling the subscriber at the C-HLR.
[0111] The VLR 20 receiving the set of subscriber data and the
subscriber identity for the subscriber, the identifier of the
C-HLR, and the identifier of the processing blade 11, stores them
during step S-104 and returns a successful result during step S-105
towards the processing blade 11 handling the corresponding
subscriber at the C-HLR 10.
[0112] To this end, the secondary subscriber register 20
illustrated in FIG. 10, which in this third embodiment is the VLR
20, comprises a storage 21 arranged for storing the subscriber
identity 211 and the subscriber data 212 for the subscriber, the
identifier 213 of C-HLR and the identifier 214 of the processing
blade 11 for the subscriber at the C-HLR; and a processor 24
arranged for processing a course of actions to be taken for the
subscriber depending on the received subscriber data.
[0113] The processing blade 11 handling this subscriber may now
return a successful result for the location updating procedure
towards the VLR 20 currently serving the subscriber 1, either
directly during a step S-108 as illustrated in FIG. 11b, or
indirectly through the distributor 14 during steps S-106 and S-107
as shown in FIG. 1.
[0114] At this stage, once the method for location updating between
a C-HLR and a VLR has been discussed in accordance with this third
embodiment, the restoration procedure anticipated above can be
further discussed in detail.
[0115] In principle, the so-called restoration procedure is one
amongst the recovery procedures that may be applied after having
recovered from a failure situation. This might be the case where a
subscriber register has suffered a sort of restart and a data
dumping has taken place, likely from a reload tape or disk. This
might be also the case where an R-HLR has been handling the
subscribers of a primary HLR during the failure, and subscriber
data have been changing therein before recovering and reloading the
primary HLR. In this context, the primary HLR is understood as the
HLR primary intended to hold subscriber data for a number of such
subscribers. Generally speaking, the restoration procedure may take
place where subscriber data stored for subscribers of a primary HLR
in one or more VLRs might have erroneous data, or data not supposed
to be up-to-data.
[0116] In particular and for the purpose of the present invention,
the restoration procedure may take place where subscriber data
stored in one or more VLRs for subscribers of a processing blade 11
of a C-HLR might have erroneous data, or data not supposed to be
up-to-data, such as the case might be where the exemplary
redundancy procedure explained above in relation with the second
embodiment has taken place, or where a data reload has taken place
after having suffered a sort of restart at a processing blade 11 of
a C-HLR.
[0117] Therefore, an exemplary restoration procedure may take place
upon detection of one of the above conditions for a processing
blade 11 at the C-HLR 10. Following the second or third embodiments
discussed above and as illustrated in FIG. 2, the processing blade
11 determines those VLRs 20, 40 which identifier is stored as
location data for these subscribers handled in said processing
blade, and sends a reset message including the identifier of the
C-HLR 10 and the identifier of the processing blade 11 in
respective steps S-111 and S-114 towards said VLRs 20, 40. In
particular, amongst said VLRs there may be a clustered subscriber
register 40 acting as a clustered VLR "C-VLR" 40, or a secondary
subscriber register 20 acting as a non-clustered VLR.
[0118] To this end, as FIG. 4 illustrates, the C-HLR may comprise a
restorer 18, which in cooperation with the processor 111 of the
processing blade 11 obtains from storage 112 those VLRs 20, 40
which identifier is stored as location data for the subscribers
handled in said processing blade, the restorer 18 cooperating with
the output unit 16 for submitting the reset message with the
identifier of the C-HLR 10 and the identifier of the processing
blade 11 towards said VLRs 20. 40. Alternatively, the restorer 18
might be unnecessary if the central processor 141 is arranged for
carrying out the required steps and functionality of this
restoration procedure.
[0119] The VLRs 20, 40 receiving such reset message in steps S-111
and S-114 respectively, initiate its local restoration by firstly
searching in respective steps S-112 and S-115 for subscribers with
the received identifier of the C-HLR 10 and the identifier of the
processing blade 11, and by secondly triggering in respective steps
S-113 and S-116 a restoration for such subscribers, which basically
may imply the withdrawal of such subscribers to force a new
location updating for them so that current up-to-data subscriber
data may be further received from the C-HLR 10.
[0120] As already commented, these VLRs may be implemented with a
clustered subscriber register acting as a clustered VLR "C-VLR" 40,
or with a secondary subscriber register acting as a non-clustered
VLR 20.
[0121] Therefore, as illustrated in FIG. 7, a C-VLR 40 may comprise
an input unit 45 cooperating with a restorer 48 for receiving the
reset message and a number of processing blades 41-43, each
processing blade 42 having storage 422 for storing subscriber data
for a number of subscribers and a processor 421 arranged for
processing the course of actions to be taken for the subscribers
depending on subscriber data for each subscriber, in this case, for
triggering the withdrawal of subscribers found with the identifier
of the C-HLR 10 and with the identifier of the processing blade 11
in the storage 422. Alternatively, the restorer 48 might be
unnecessary if the central processor 441 carries out corresponding
restoration functions in lieu of the restorer.
[0122] On the other hand, a secondary subscriber register 20 acting
as a non-clustered VLR 20 may comprise, as illustrated in FIG. 10,
an input unit 25 cooperating with a restorer 28 for receiving the
reset message and a with a processor 24 arranged for processing the
course of actions to be taken for the subscribers depending on
subscriber data for each subscriber in storage 21. In this case,
for triggering the withdrawal of subscribers in storage 211 found
with the identifier of the C-HLR 10 in storage 213 and with the
identifier of the processing blade 11 in storage 214. Alternatively
as for other embodiments, the restorer 28 might be unnecessary if
the central processor 24 carries out corresponding restoration
functions in lieu of the restorer.
[0123] As for previous embodiments, the method described
hereinbefore for this third embodiment, as well as the structural
elements that form the clustered and the secondary subscriber
registers, especially in respect of the above third embodiment,
allow recovery procedures such as the so-called restoration
procedure to be carried out for network nodes such as HLR, VLR,
HSS, S-CSCF, and R-HLR with higher performance and memory capacity
whilst keeping the overall network performance, signalling load and
response times up to reasonable levels and measurements.
[0124] In a fourth embodiment of the invention illustrated in FIG.
8, there is provided a method of updating subscriber data between a
clustered subscriber register 50 acting as a HSS, namely a
clustered HSS "C-HSS", and a secondary subscriber register acting
as an S-CSCF. This method may preferably apply in the scenario
basically illustrated in FIG. 6 wherein a subscriber 1 attaches via
a radio interface an IP Multimedia Subsystem "IMS" of a 3.sup.rd
generation mobile network through radio premises not shown for the
sake of simplicity. The subscriber registers in a P-CSCF 98, from
where a corresponding registration message is submitted towards an
I-CSCF 96. The I-CSCF 96 queries the HSS 50, 70 in order to obtain
capabilities required for assigning a serving node for serving the
subscriber. Once such capabilities are received from the HSS, the
I-CSCF selects and assigns an S-CSCF 60, 80 suitable for serving
the subscriber, and submits the registration message towards said
S-CSCF. The S-CSCF then submits a message towards the HSS
indicating to be assigned for serving the user, the indication
including an identifier of said S-CSCF, an obtains from the HSS a
user profile, including the subscriber data for the subscriber,
along with an identifier of the HSS.
[0125] The method in this third embodiment, as illustrated in FIG.
8, starts with a step S-131 of registering a subscriber 1 into a
P-CSCF 98 of the IMS. The P-CSCF 98 submits the registration
message towards the I-CSCF 96 in a step S-132. The I-CSCF 96
queries a C-HSS 50 during step S-133 to obtain capabilities
required for assigning an S-CSCF.
[0126] To this end, as illustrated in FIG. 9, the C-HSS 50 includes
an input unit 55 arranged for receiving said query about required
capabilities for the subscriber from the I-CSCF 96. Since this
C-HSS comprises a plurality of processing blades 51-53, a
particular processing blade 52 must be determined for handling this
subscriber. This particular processing blade 52, as each processing
blade 51-53, handles a number of subscribers and comprises: storage
522 arranged for storing subscriber data for the subscriber 1, and
a processor 521 arranged for processing a course of actions to be
taken for the subscriber depending on subscriber data for said
subscriber. To this end, the C-HSS 50 includes a distributor 54,
the so-called DM in this instant specification, for determining the
processing blade 52 currently handling the subscriber. In
particular, this distributor may include a central processor 541
for carrying out common routines for all the processing blades as
well as for controlling the availability status for each processing
blade. Then, the input unit 55 internally passes the query to the
distributor 54, which is the internal entity receiving the query
during this step S-133.
[0127] The sequence of actions illustrated in FIG. 8 thus continues
with a step S-134 of determining at the distributor 54 of the C-HSS
50 the processing blade 12 handling the subscriber, and internally
passing the query received for the subscriber to said processing
blade 12 during step S-135. Then, the processing blade receiving
such query, or rather its local processor 521, returns during step
S-136 an identifier of the C-HSS 50 and an identifier of the
processing blade 12 along with the requested capabilities.
[0128] To this end, the local processor 521 cooperates with an
output unit 56 for returning these data during the step S-136.
Alternatively and depending on different implementations, the
central processor 541 might also participate in this step of
returning the identifier of the C-HSS 50 and the identifier of the
processing blade 12 along with the requested capabilities.
[0129] In view of the received capabilities, the I-CSCF 96 selects
an S-CSCF 60 fitting such capabilities and assigns it to the
subscriber by forwarding to said S-CSCF 60 during step S-137 the
registration message, after having included therein the received
identifier of the C-HSS 50 and the received identifier of the
processing blade 12. Upon receipt of such registration message, the
S-CSCF 60 informs the C-HSS of being assigned for serving the
subscriber and updates the subscriber location data therein, namely
an identifier of the S-CSCF currently serving the subscriber, by
submitting during step S-138 this location data along with the
identifier of the C-HSS 50 and the identifier of the processing
blade 12.
[0130] To this end, the secondary subscriber register 60 acting as
the S-CSCF 60 in this fourth embodiment, as illustrated in FIG. 10,
comprises an output unit 26 cooperating with a processor 24 for
this submission.
[0131] The C-HSS 50 receiving such location updating message,
downloads towards the S-CSCF a subscriber profile for the
subscriber along with the identifier of the C-HSS 50 and the
identifier of the processing blade 12, the subscriber profile
including the subscriber data for the subscriber. The S-CSCF 60
receiving the subscriber profile and a subscriber identity for the
subscriber, the identifier of the C-HSS, and the identifier of the
processing blade 12, stores them during a step not shown in any
drawing, and returns a successful registration result during step
S-140 towards the I-CSCF 96. the I-CSCF forwarding this result
during step S-141 towards the P-CSCF, and the latter forwarding it
towards the subscriber 1 during step S-142.
[0132] To this end, as illustrated in FIG. 9, the C-HSS 50
comprises an input unit 55 arranged for receiving said location
data for the subscriber from the S-CSCF 60 and an output unit 56
arranged for submitting the subscriber identity and subscriber
profile for the subscriber, the identifier of the C-HSS 50, and the
identifier of the processing blade 12 handling the subscriber
towards a secondary subscriber register 60, which in this case is
the S-CSCF 60 in the IMS network.
[0133] On the other hand, the secondary subscriber register 60
illustrated in FIG. 10, which in this fourth embodiment is the
S-CSCF 60, comprises an input unit 25 arranged for receiving from
the C-HSS 50 the subscriber identity and subscriber profile for the
subscriber, the identifier of the C-HSS 50, and the identifier of
the processing blade 12 handling the subscriber at the C-HSS; a
storage 21 arranged for storing the subscriber identity 211 and the
subscriber data 212 in the subscriber profile for the subscriber,
the identifier 213 of C-HSS and the identifier 214 of the
processing blade 12 for the subscriber at the C-HSS; and a
processor 24 arranged for processing a course of actions to be
taken for the subscriber depending on the received subscriber
data.
[0134] This method described for this fourth embodiment, as well as
the structural elements that form the clustered and the secondary
subscriber registers, allow recovery procedures such as the
so-called restoration procedure to be carried out tor the HSS and
the S-CSCF, with higher performance and memory capacity whilst
keeping the overall network performance, signalling load and
response times up to reasonable levels and measurements. In this
respect, the method in this fourth embodiment may include a step of
submitting, after having recovered from a failure affecting a
processing blade, a reset indication from the C-HSS 50 towards
those S-CSCF 60, 80 holding subscriber data for those subscribers
handled by the recovered blade, the reset indication including the
identifier of the C-HSS 50 and the identifier of the recovered
processing blade. Even though this procedure is not illustrated in
any drawing where applying between a C-HSS and a S-CSCF, those
skilled in the an would appreciate that the teaching in the above
third embodiment may also be applied between the C-HSS and the
S-CSCF.
[0135] Moreover, the clustered subscriber register acting as a
C-HSS may have a redundant HSS for holding redundant subscriber
data for subscribers hold by the C-HSS. The method in this fourth
embodiment may thus include a step of coordinating between the
C-HSS 50 and the redundant HSS a redundancy procedure for sending
subscriber data for those subscribers handled in a processing blade
51-53 identified by a given identifier. Even though this procedure
applying between a C-HSS and a redundant HSS is not illustrated in
any drawing, those skilled in the art would appreciate that the
teaching in the above second embodiment may also be applied between
the C-HSS and the redundant HSS.
[0136] Furthermore, the clustered subscriber register may also act
as a S-CSCF wherein a similar architecture as the ones illustrated
in FIGS. 4, 7 and 9 may be applicable to this end.
[0137] Therefore, the method described hereinbefore for the four
embodiments, as well as the structural elements that build up the
clustered and the secondary subscriber registers, allow recovery
procedures such as the so-called redundancy procedure and the
so-called restoration procedure to be carried out for network nodes
such as HLR, VLR, HSS, S-CSCF, and R-HLR with higher performance
and memory capacity whilst keeping the overall network performance,
signalling load and response times up to reasonable levels and
measurements.
[0138] The invention is described above in respect of several
embodiments in an illustrative and non-restrictive manner.
Obviously, variations, and combinations of these embodiments are
possible in light of the above teachings, and any modification of
the embodiments that fall within the scope of the claims is
intended to be included therein.
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