A method and a module for shifting a call established through a first
application server in order to route it through a second application server
Field of the present invention
The present invention relates to telecommunications and in particular to
methods and systems for shifting a call established between a first user device and a
correspondent device through a first application server in order to route it through a
second application server.
Background
Some private application servers, such as enterprise communication
application servers, provide much more communication services than public network
communication application servers. Enterprise communication servers typically
provide supplementary services such as call recording, video conferencing,
consultation calls, transferring, call shifting between a set of user terminal devices,
and others.
When a user, who is o registered subscriber of such a private application
server, happens to initiate or receive a communication directly through the public
network, he is not in position to benefit from the full services of the private application
server, e.g. his enterprise application server. For example, the user involved in a
mobile communication, managed by a mobile network telephony application server,
cannot escalate this communication to a full collaboration session, this escalation
capability being only available through his enterprise communication application
server, which is not involved in the communication so far.
Therefore, in order to benefit from the supplementary services of the private
application server, the user must hang-up the communication and, then, he re¬
establishes the call using the private application server. To that end, the user needs to
choose the private application server, re-find the contact of the other user and
establish a new call through the private application server.
W
2
Such process is bothersome, time consuming and should therefore be
avoided.
FR 2 935 858 discloses a telecommunication method that allows shifting a
call established through a server of the public network in order to route it to an
enterprise application server. FR 2 935 858 discloses that a first user terminal may
send a server shift instruction and that upon a server shift instruction has been
received, the public network is instructed to reroute the call towards the enterprise
application server.
The public network stops the call with the terminal of the first user, suspends
the call with the correspondent device and performs a call towards the enterprise
application server. Then, the enterprise application server establishes a call with the
terminal of the first user which accepts the call.
Summary
Various embodiments provide a method and module for automatically
shifting a call established through a first application server in order †o route it
through a second application server.
In a first embodiment, a method for shifting an original call established
between a first user device and a correspondent device through a first application
server in order to route it through a second application server is provided. The
method comprises:
- receiving a server shift instruction;
-instructing the first application server to forward the original call through the
second application server to the first user device upon receiving the application server
shift instruction, the first application server being instructed to establish a three-way
conference communication between the first user device, the correspondent device
and the second application server in order to forward the original call from the first
application server to the second application server;
-determining that an incoming call routed from the second application
server to the first user device has an identification information which matches
identification information of the original call;
-causing the first user device to pick-up the incoming call routed from the
second application server to the first user device and instructing to release the call
branch between the first application server and the first user device upon determining
that the identification information matches.
Thus, the call can be automatically shifted through the second application
server and the users can benefit from the full services of the second application
server.
Thanks to these features, the call can be shifted seamlessly.
In some embodiments, such a method may comprise one or more of the
features below:
- the method comprises a step of instructing the first application server to tag
the original call forwarded from the first application server to the second application
server in order to generate identification information of the original call;
- the method comprises a preliminary step of determining that there is a
valid route between the second application server and the first user device;
- the method comprises receiving a notification that an original call is
established between the first user device and the correspondent device through the
first application server and sending an invitation to shift the call through the second
application server;
- the method comprises providing the first application server with the second
application server address and information representative of the first user device
address, the said information representative of the first user device address being a
first user device address or a unique contact address assigned to the first user in
order to forward the original call from the first application server to the second
application server and route it to the first user device.
In a second embodiment, a module for shifting an original call established
between a first user device and a correspondent device through a first application
server in order to route it through a second application server is provided. The
module comprises:
- an engine which is configured to:
o instruct the first application server to forward the original
call through the second application server to the first user
device upon receiving an application server shift instruction,
, the first application server being instructed to establish a
three-way conference communication between the first user
device, the correspondent device and the second application
server in order to forward the original call from the first
application server to the second application server;
o determine that an incoming call routed from the second
application server to the first user device has an
identification information matches identification information
of the original call;
cause the first user device to pick-up the incoming call
routed from the second application server to the first user
device upon and cause releasing of the call branch between
the first application server and the first user device
determin ing that the identification information matches.
In some embodiments, such a module may comprise one or more of the
features below:
- the engine is configured to instruct the first application to tag the call
forwarded from the first application server to the second application server in order to
generate identification information of the original call;
- the engine is configured to determine that there is a valid route between
the second application server and the first user device;
- the module comprises a control user interface or a control user interface
connector and the engine is configured to generate through the control user interface
or the control user interface connector an invitation to shift the call through the
second application server, upon detecting that the original call is established between
the first user device and the correspondent user device through a first application
server;
-the module comprises application servers connectors for connecting the
said module to the first and the second application servers; and/or
- the module comprises a device telephony resources connector for
connecting the said module to the first user device.
According to a third embodiment, a system comprising an application server
and a module according to the second embodiment associated with the application
server is provided.
According to a fourth embodiment, a system comprising a user device and a
module according to the second embodiment associated with the user device is
provided.
Brief description of the drawings
These and other aspects of the present invention will be apparent from and
elucidated with reference to the embodiments described hereinafter, by way of
example, with reference to the drawings.
• Figure 1 is a functional diagram showing the architecture of a
module for shifting an original call established between a first user
device and a correspondent device through a first application server
in order to establish it through a second application server.
• Figure 2 is a diagram showing a network wherein a call is
established between a first user device and a correspondent device
through the first application server.
• Figure 3 is a diagram showing the network of figure 2 wherein the
call has been shifted so that the call is now routed through a second
application server.
• Figure 4 is a time diagram illustrating the steps of a method
according to an embodiment.
Detailed description of the embodiments
The described exemplary embodiment relates to a method and module for
shifting a call established through a first application server 3, such as a public
application server, in order to route it through a second application server 4, such as
a private application server, in a SIP (Session Initiation Protocol) supporting network
such as an IMS (Internet Multimedia subsystem) network. However, though the
invention may be applied within the scope of the IMS network, it may also apply to
other architectures.
Typically, the second application server 4 can provide users with many more
services such as recording, video conferencing, consultation calls, transferring, call
shifting between a set of user terminal devices.
The network, illustrated in Figures 2 and 3, comprises a first user device 1, a
correspondent device or second user device 2, a first application server 3, a second
application server 4 and a module 5 for shifting a call established through the first
application server 3 in order to establish it through the second application server 4 .
The module 5 is referred to as CAS module 5, for Communication Application Shift
module, in the hereinafter description.
The first user device 1 and the correspondent device 2 may be any kind of
telecommunication end user equipment, such as mobile phones, personal digital
assistants, fixed phones, etc.
Moreover, the invention is not limited to embodiments in which the network
comprises only two application servers and may also be applied with any number n
of application servers, n being two o r more.
The CAS module 5, shown in detail in figure 1, comprises an engine 5 1, a
control user interface 52, a device telephony resources connector 5 3 for connecting
the said CAS module 5 to at least the first user device 1 and application server
connectors 54 for connecting the said CAS module 5 to the n application servers: the
first 3 and the second 4 application servers in the illustrated embodiment.
The engine 5 1 is a microcontroller or a microprocessor associated with a
memory and suitable software o r software program.
The CAS module 5 may be implemented in the first user device and/or in
any one of the application servers.
The CAS module 5 may have its own control user interface 52 but it may
also use the control user interface of the first user device 1 through a suitable control
user interface connector. The control user interface 52 enables the end user to be
notified about an established original call and to communicate application server
shift instruction to the CAS module 5. Alternatively, instructions for the CAS module 5
are entered through the control user interface of the first user device 1 via the control
user interface connector.
The method for shifting a call according to an embodiment will now be
described in detail.
As a preliminary step (STEP 100, STEP 10 1), the engine 5 1 of the CAS
module 5 subscribes to both the first 3 and the second 4 application servers through
their application server connectors 54 and their respective control interfaces, not
shown in details.
Of course, the first user is a registered subscriber of the first application
server 3 and the second application server 4 .
In an embodiment, the second application server 4 provides services which
allow a user having a set of user devices to answer a call with anyone of his devices
and/or to shift a call between his devices. To that end, the second application server
4 is linked to a user profile register which assigns to the first user a unique contact
address which can be used to address a call to a set of first user devices.
The CAS module 5 is informed of any call directed to the first application
user through any of the first 3 and second 4 application servers. The engine 54 is
also able to determine whether there is a valid route between the first application
server 3 and the first user device 1, whether there is a valid route between the second
application server 4 and the first user device 1 and whether there is a valid route
between the first 3 and the second 4 application server.
When an original call is started or received from/by the first user device 1
through the first application server 3 so that a call 2 1 is established between the first
user device 1 and the correspondent device 2 through the first application server 3,
as shown in figure 1, the method for shifting c n be implemented as follows.
As long as a call 20 is established through the first application server 3, the
engine 5 1 of the CAS module 5 received a notification from the first application
server through the relevant application server connector 54 that an original call is
established between the first user device 1 and the correspondent device 2 through
the first application server 3 (STEP 200). Then, the engine 5 1 checks whether an
application server shift instruction is received from the first user via the control user
interface 52 or via the first user device 1 through the control user interface connector.
In a preferred embodiment, the engine 5 1 also generates an invitation (STEP 300) to
offer the first user with a capability to shift the call through the second application
server 4 . The invitation can be made visible to the first user through the control user
interface 52 so that the first user can trigger a n application server shift instruction
through the control user interface. Alternatively, the invitation can be made visible to
the first user through to the first user device 1 so that the first user can trigger an
application server shift instruction through the first user device .
The invitation to shift the call 2 1 may explicitly invite the first user to shift the
call through the second application server or may invite the first user to benefit from
one or several services which are only available through the second application
server 4 . The invitation may be implemented as an icon on a touch screen or any
similar trigger.
According to another embodiment, an application server shift instruction
may be automatically triggered in response to receiving the invitation from the CAS
module 5 .
Upon an application server shift instruction being received (STEP 400), the
engine 5 1 instructs the first server application 3 through the relevant application
server connectors 54 to forward the call from the first application server 3 to the
second application server 4 (STEP 500).
During the forward instruction step (STEP 500), the engine 5 provides the
first application server 3 with the second application server 4 address and, optionally,
first user address information representative of the first user device address or of the
first user himself. The first user address information may be the address of the first
user device 1 for the second application server 4 or a unique contact address
assigned to the first user himself. In that case, as previously mentioned, the user
address is mapped to a set of devices of the first user which comprises the first user
device 1.
According to an embodiment, the engine 5 1 instructs the first server
application 3 to transfer the call to the second application server 4 . In a more
advantageous embodiment, the engine 5 1 instructs the first server application 3 to
establish a conference communication between the first user device 1, the
correspondent device 2 and the second application server 4. The instruction to
transfer the call or to establish a conference communication is, for instance, a set of
instructions, such as a n INVITE and/or RE-INVITE SIP requests.
The engine may also instruct the first application server 3 to tag the call
in order to generate identification information of the original call.
The original call is thus tagged and forwarded from the first application
server 3 to the second application server 4 (STEP 600). Then, the call is routed from
the second application server 4 to the first user device 1 (STEP 700). The CAS module
5 is simultaneously informed by the second application server 4 through the
application server connector 54 of the incoming call routed from the second
application server 4 to the first user device 1 (STEP 701 ) .
As a result of step 701 , an incoming call is received on the first user device
1. The engine 5 1 determines whether the incoming call routed from the second
application server 4 has identification information which matches identification
information of the original call. The identification information may be a call ID or the
tag which has been generated by the first application server 3 and communicated to
CAS module 5 .
If the identification information matches, the engine 5 1 instructs the first user
device 1 via the device telephony resources connector 53 to automatically pick-up the
call routed from the second application server 4 (STEP 800).
In the more advantageous embodiment, in which a three-way conference
communication is established by the first application server 3 between the first user
device , the correspondent device 2 and the second application server 4, the engine
5 1 instructs the first user device 1 through the device telephony resources connector
53 to pick-up the incoming call routed from the second application server 4 and to
release the call branch between the second application server 4 and the first user
device 1 (STEP 800). Depending on multiline capability of the first user device , the
picking-up and the releasing can be simultaneous so that the call is shifted seamlessly
or the call routed from the first application server 3 is firstly released and then the call
routed from the second application server 4 is picked-up.
The communication call 2 1 is thus established between the first user device 1
and the correspondent device 2, via the second application server 4 and eventually
via the first application server 3, so that the users can benefit from the full services of
the second application server 4 (see figure 2).
The methods described hereinabove may be executed through the use of
dedicated hardware as well as hardware capable of executing software in association
with appropriate software. When provided by a processor, the corresponding
functions may be provided by a single dedicated processor, by a single shared
processor, or by a plurality of individual processors, some of which may be shared.
Moreover, explicit use of the term "processor" or "controller" should not be construed
to refer exclusively to hardware capable of executing software, and may implicitly
include, without limitation, digital signal processor (DSP) hardware, network
processor, application specific integrated circuit (ASIC), field programmable gate
array (FPGA), read-only memory (ROM) for storing software, random access memory
(RAM), and non-volatile storage. Other hardware, conventional and/or custom, may
also be included.
The invention is not limited to the described embodiments. The appended
claims are to be construed as embodying all modification and alternative
constructions that may be occurred to one skilled in the art, which fairly fall within the
basic teaching here, set forth.
The use of the verb "to comprise" or "to include" and its conjugations does
not exclude the presence of elements or steps other than those stated in a claim.
Furthermore, the use of the article "a" or "an" preceding an element or step does not
exclude the presence of a plurality of such elements or steps.
In the claims, any reference signs placed between parentheses shall not be
construed as limiting the scope of the claims.
It is to be understood that, within the scope of the appended claims, the
invention may be practiced otherwise than as specifically described herein.

CLAIMS
1. A method for shifting an original call established between a first
user device ( ) and a correspondent device (2) through a first application server (3) in
order to route it through a second application server (4), the method comprising:
receiving a server shift instruction;
instructing the first application server ( 1 ) to forward the original call
through the second application server (4) to the first user device ( 1) upon
receiving the application server shift instruction, the first application
server being instructed to establish a three-way conference
communication between the first user device ( 1), the correspondent
device (2) and the second application server 4) in order to forward the
original call from the first application server (3) to the second application
server (4);
determining that an incoming call routed from the second application
server 4 ) to the first user device ( 1) has an identification information
which matches identification information of the original call;
causing the first user device ( 1 ) to pick-up the incoming call routed from
the second application server (4) to the first user device (1) and
instructing to release the call branch between the first application server
(3) and the first user device ( 1 ) upon determining that the identification
information matches.
2. A method according to claim 1, comprising a step of instructing the
first application server (3) to tag the original call forwarded from the first application
server (3) to the second application server 4) in order to generate identification
information of the original call.
3. A method according to claim 1, comprising a preliminary step of
determining that there is a valid route between the second application server (4) and
the first user device (1).
4 . A method according to claim 3, comprising receiving a notification
that an original call (20) is established between the first user device ( 1 ) and the
correspondent device (2) through the first application server (3) and sending an
invitation to shift the call through the second application server (4).
5 . A method according to claim 1, comprising providing the first
application server (3) with the second application server (4) address and information
representative of the first user device ( 1 ) address, the said information representative
of the first user device(l ) address being a first user device ( 1 ) address or a unique
contact address assigned to the first user in order to forward the original call from the
first application server (3) to the second application server (4) and route it to the first
user device ( ).
6 . A module 5) for shifting an original call established between a first
user device ( 1) and a correspondent device (2) through a first application server (3)
in order to route it through a second application server (4), the module comprising :
an engine (51 ) which is configured to :
o instruct the first application server ( 1 ) to forward the original call
through the second application server (4) to the first user device
( 1 ) upon receiving an application server shift instruction, the first
application server ( 1) being instructed to establish a three-way
conference communication between the first user device ( 1), the
correspondent device (2) and the second application server (4) in
order to forward the original call from the first application server
(3) to the second application server (4);;
o determine that an incoming call routed from the second
application server (4) to the first user device ( 1} has an
identification information matches identification information of
the original call ;
o cause the first user device ( ) to pick-up the incoming call routed
from the second application server (4) to the first user device ( 1 )
and cause releasing of the call branch between the first
application server (3) and the first user device ( 1 ) upon
determining that the identification information matches.
7. A module (5) according to claim 6, wherein the engine (51 ) is
configured to instruct the first application server (3) to tag the original call forwarded
from the first application server to the second application server in order to generate
identification information of the original call.
8 . A module according †o claim , wherein the engine (51 ) is
configured to determine that there is a valid route between the second application
server (4) and the first user device ( 1 ).
9 . A module according to claim 8, wherein the engine (51 ) is
configured to generate through a control user interface (52) or a control user
interface connector an invitation to shift the call through the second application server
(4), upon detecting that the original call established between the first user device ( 1
and the correspondent device (2) through a first application server (3).
10 . A module according to claim 7, comprising application servers
connectors (54) for connecting the said module (5) to the first and the second
application servers (3, 4).
11. A module according to claim 7, comprising a device telephony
resources connector (53) for connecting the said module (5) to the first user device
( 1);
. A system comprising an application server (3, 4) and a module (5)
according to any of claims 6 to 1 associated with the said application server.
13 . A system comprising a user device ( 1 ) and a module (5) according
to any of claims 6 to 11 associated with the user device ( 1 ) ,