A) TECHNICAL FIELD
[0001] The present invention generally relates to telecommunications
systems and methods and more particularly relates to a relay mechanism for
communicating SS7 messages in a Signaling System 7 (SS7> network. .
B) BACKGROUND OF THE INVENTION
[0002] Modem public-switched telephone networks (PSTN) use a
signaling protocol, e.g. signaling system No. 7 (SS7) for switching of
telephone calls. A key challenge for GSM Network is to send the multiple IN
trigger (InitialDP) to different IN services for any call.
[0003] In order to provide consistent and reliable communication across
the signaling network infi-astructure, a common or standard digital signaling
protocol known ,as Signaling System 7 (SS7) has been'developed. SS7 is an
out of band common channel signaling system that uses labeled messages to
transport circuit related signaling information, non-circuit related ' signaling
information, network resident database service information and other
information that may be used for the establishment of communication
services.
[0004] From a hardware perspective, an SS7 network includes a
plurality of SS7 nodes, generically referred to as Signaling Points (SP), that
are interconnected using signaling links, also referred to as SS7 links. At least
three types of SPs are provided in an SS7 network: Service Switching Points
(SSP), Signal Transfer Points (STP) and Service Control Points (SCP). SS7
also includes a, network protocol. As a protocol, SS7 defines a hierarchy or
structure of the information contained in a message or data packet that is
transmitted between SPs of an SS7 network over signaling links.
[0005] Currently, the Call Manager Service supports both Prepaid and '
Postpaid subscribers. If the Prepaid subscriber has subscribed to any Mobile
Terminated IN service such as Call Manager and subscriber is roaming in
different networks, then GSMSSF cannot trigger to Call Manager service
because for Prepaid subscriber, the incoming call should be charged in
roaming. Hence GSMSSF will send the IN trigger to PPS service for call
handling. In this scenario, the subscriber will not be able to use the call
manager service.
[0006] '
To provide the call Manager Service to a Prepaid roaming
subscriber, the Call ,Manager Platform need to act as an Intelligent Network
(IN) Gateway between the GSMSSF and PPS service. However, in this case
the Call Manager Platform will be in entit'e call session and needs to forward
all the responses received from IN service/PPS to the network. Thls in turn
increases the Signaling Llnk Code (SLC) requirements to handle all the calls
and because of more signaling l~nksre quirement, it increases the hardware or
license requirements, which in turn increases the cost.
[0007] In view of the foregoing, there is a need to provide an effective
signaling mechanism which provides for. handover of IN Trigger to PPS
service after call handing at Call Manager Platform to reducing the call set up
time.
[0008] The above mentioned shortcomings, disadvantages and
problems are addressed herein, which will be understood by reading the
following specification.
C) OBJECTS OF THE INVENTION
[0009] The priinary object of the present invention ,is to provide a
signaling mechanism for handover of Intelligent Network (IN) trigger to PPS
service after call handling at .Call Manager Platform, according to an
embodiment of the present invention.
[0010] Another object of the present invention is to provide a signaling
mechanism to reduce transactional signaling traffic, according to an
embodiment of the present invention.
[0011] Another object of the present invention is to provide a signaling
mechanism to reduce signaling link requirements, according to an
embodiment of the present invention.
[0012] Another object of the present invention is to provide a signaling
mechanism to reduce licensing requirements of Signaling link, according to
an embodiment of the present invention.
, [0013] Another object of the present invention is to provide a signaling
mechanism'to reduce Transaction per second (TPS) of service which in turns
reduce the Application servers (Hardware) ,power Requirements ,Rack Space
requirements., according to an embodiment of the present invention.
[0014] Another object of the present invention is to provide a signaling
mechanism to reduce the call set up time by removal of additional hop,
according to an embodiment of the present invention.
[0015] Another object of the present invention is to provide a signaling
mechanism to reduce the operational cost, according to an embodiment of the
present invention.
[0016] These and other objects and advantages of the present invention
will become readily apparent from the following detailed description taken in
conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0017] The various embodiments of the present invention provide a
method -of transferring Signaling System 7 (SS7) messages in an SS7
. .
network. The method comprises of providing an intermediate signaling layer
between a SS7 Transaction Capability Application Part (TCAP) layer and a
SS7 Signaling ,Connection Control Part (SCCP) layer, receiving, by the
. .
intermediate signaling layer, a first SS7 message from the SCCP layer,
transmitting the first SS7message to the TCAP layer, providing, by the TCAP
layer the first SS7message to a Call Manager.Platform for call handling and
sending, by the TCAP layer a second SS7 message to the SCCP layer through
the intermediate signaling layer.
[0018] According to an embodiment of the present invention, the
intermediate signaling layer is a Modulel5.
[0019] According to an embodiment of the present invention, the
. intermediate signaling layer extracts and stores a plurality of message
information elements from the first SS7message before transmitting the first
message to the TCAP layer.
[0020] According to an embodiment of the present invention, the
plurality of message information elements extracted from the first SS7
message comprises at least one of calling Party GT Address, called Party GT
Address and orig Transaction LD.
[0021] According to an embodiment of the present invention. the Call
Manager Platform performs call handling by analyzing a CgPN and a CdPN
associated with the first SS7 message to check if a call is allowed or not and
sending the first SS7 message to a CAMEL Application Part (CAP) layer to
handover the first SS7 to a Prepaid Service (PPS) through a Signal Transfer
Point (STP), if the call is allowed.
[0022] According to an embodiment of the present invention; the
method hrther comprises of sending, by the PPS, a response back to a
GSMSSF from where the call has been triggered, recognizing, by the
GSMSSF the Transaction ID and processing the response received from the
PPS service.
[0023] According to an embodiment of the present invention sending
by the TCAP layer a second SS7 message to the SCCP layer through the
intermediate signaling layer comprises of receiving a second SS7 message
fiom the TCAP layer, checking if an IDP handover request is present or not '
in the second SS7 message, replacing an.plurality of information elements
associated with the second SS7 message with the pre-stored information
elements if the IDP handover request is present and forwarding the second
SS7 message to the SCCP Layer through the intermediate signaling layer.
[0024] According to an embodiment of the present invention, the
method Wher comprises of transferring, by the SCCP Layer, the second SS7
message to a lower layer .to send the second SS7 message to an Intelligent
Network (IN).
[0025] According to an embodiment of the present invention, the
Transaction ID of the first SS7 message and the second SS7 message is same.
[0026] According to an embodiment of the present invention, the
intermediate signaling layer is provided between the TCAP layer and the
SCCP layer of an SS7 stack to support an SS7 message relay.
[0027] These and other aspects of the embodiments herein will be
better appreciated and understood when considered in conjunction with the
following description and the accompanying drawings. It should be
understood, however, that 'the following descriptions, . while indicating
preferred embodiments and numerous specific details thereof, are given by
way of illustration and not of limitation. Many changes and modifications
may be made w i t h the scope of the embodiments herein without departing
from the spirit thereof, and the embodiments herein include all such
modifications.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The other objects, features and advantages will occur to those
skilled in the art fiom the following description of the preferred embodiment
and the accompanying drawings in which:
[0029] FIG.1 is ,an architecture of the Greenroom Platform for
providing call management solutions, according to a prior art illustration.
[0030] FIG.2 is a signal flow diagram illustrating call manager platform
functioning as a signaling gateway, according to a prior illustration.
[0031] FIG.3 is schematic representation of protocol .stack and call
management layer, accordirig to an embodiment of the present invention.
[0032] ' FIG.4 is a schkmatic of a SS7 message flow in the intermediate
signaling layer, according to an embodiment of the present invention. .
[0033]
[0034] FIGS is a flow diagram illustrating a signal flow for IDP '
handover, according to an embodiment of the present invention.
[0035] FIG. 6 is a schematic diagram depicting a TCAP message Relay,
according to an exemplary illustration of the present invention.
[0036] Although specific features of the present invention are shown in
some drawings and not in others. This is done for convenience only as each
feature may be 'combined with any or all of the other features in accordance
with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0037] In the following detailed description, reference is made to the
accompanying drawings that form a part hereof, and in which the specific
embodiments that may be practiced is shown by way of illustration. These
embodiments are described in sufficient detail to enable those skilled in the
art to practice the embodiments and it is to be understood that the logical,
mechanical and other changes may be made without departing from the scope
of the embodiments. The following detailed description is therefore not to be
taken in a limiting sense.
[0038] The various embodiments of the present invention provide
amethod for transfening Signaling System 7 (SS7) messages in an SS7
network. The method comprises of providing an intermediate signaling layer
between aSS7 Transaction Capability Application Part (TCAP) layer and a
SS7 Signaling Connection Control Part (SCCP) layer, receiving, by the
intermediate signaling layer, a first SS7 message from the SCCP layer,
transmitting the first SS7 message to the TCAP layer, providing, by the
TCAP layer the frrst SS7 message to a Call Manager Platform for call
.handling and sending, by the TCAP layer a second SS7 message to the SCCP
layer through the intermediate signaling layer.
[0039] FIG.l is an archtecture of the Greenroom Platform for
providing call management solutions, according to a prior art illustration. ,The
Call Manager service provides countless possibilities for customizing the
incoming voice call handling and allowing various pre-defined actions or
responses. The Call Manager service would be however invaluable for
customers who want to control the way they keep in touch with business
contacts, family, and friends.
[0040] In addition, the call management system could block unwanted
calls and set a sophisticated rule to handle them. The Call Manager Service
supports both Prepaid and Postpaid subscribers. Call management solution is
based on Greenroom Platform Architecture and Dialogic products for call .
control, signaling, and media.
[0041] FIG.2 is a signal flow diagram illustrating a call manager
platform functioning as a signaling gateway, according to a prior illustration.
The SS7 platform provides distributed execution of protocol layers to
facilitate scaling and performance tuning by adding - or load-balancing
processing components without application changes. To provide the call
Manager Service to Prepaid roaming subscriber, the Call Manager Platform
need to act as an IN Gateway between GSMSSF and PPS service. In this case
Call Manager Platform will be in entire call sessi0.n and unnecessary Call
Manager Platform resources will be occupied for entire session.
,
[0042] FIG.3 is schematic representation of protocol stack, and call
management layer, according to an embodiment of the present invention. The
SS7 Platform provides distributed execution of protocol layers to facilitate
addition of service layer between any layers. As shown in Fig. 3, an
intermediate signaling layer called as "~odulel5"3 10 is introduced between
'a Signaling Connection Control Part(SCCP)layer 308and a Transaction
Capabilities Application Part(TCAP) layer 3'12 to support an Initial DP
message (SS7 Message) Handover to a prepaid (PPS) Service. The Module15
310 is adapted to Handover the received incoming message (CAMEL
InitialDP) from MSCISTP to PPS Service (IN Node) via STP in a transparent
manner. The TCAP Transaction ID in secondSS7 message (CAMEL
InitialDP) will be same as that received in the first SS7 message (CAMEL
InitialDP).In this case PPS service, will send the response back to GSMSSF
from where IDP has been triggered to Call Management Platform 3 16 for MT
calls.
[0043] FIG.4 is a schematic of a SS7 message flow in the intermediate
signaling layer, according to an embodiment of the present invention. The
Module1 5 3 10 receives the TC Begin (TCAP message) from the SCCP layer
308. The TCAP message comprises a plurality of information elements such
as the Calling Party GT Address, Called Party GT Address and the Orig
Transaction ID. The Module 15 310, extracts the Calling Party GT Address,
Called Party GT Address and Orig Transaction ID from the first SS7 message
(incoming message) and store in the memory and pass the first SS7 message
to the TCAP layer 3 12.
[0044] The TCAP layer 312 will then transfer the first SS7 message to
the CAP layer 3 14. The CAP Layer 3 14 then sends the first SS7 message to
Call Manager Platform 3 16 for call handing. The Call Manager platform then
analyze the CgPN and CdPN and if a call is allowed, then the Call Manager
Platform sends a second SS7 message to the CAP layer 3 14 to handover the
second SS7 message to the PPS via a Signaling Transfer Point (STP).
[0045] According to an embodiment of the present invention, the
terminologies first SS7 message, and initial DP and second SS7 message is
used for the incoming message and outgoing message respectively,
throughout the specification.
[0046] When Module15 310 receives the outgoing TC begin message
fiom TCAP layer 3 12, the Module15 310 checks if an IDP handover request
is present in the second SS7 message. If an IDP handover request is present,
then the Module1 5 3 10, replaces the new Orig Trans ID with stored incoming
Orig Trans ID and pass to the second SS7 message to the SCCP layer 308.
The SCCP Layer 308 then passes the second SS7 message to a lower layer to
send the second SS7 message to a network 302.
[0047] According to the embodiment herein, the STP sends the IDP
message to the PPS service. The PPS service sends a response back to
GSMSSF from where call has been triggered. The GSMSSF then recognizes
the Transaction ID and process the response received fi-om PPS service.
[0048] FIGS is a flow diagram illistrating a signal flow for JDP
handover, according to an embodiment of the present invention. The
embodiments herein consider a case where, the calling party is not blocked
by the called subscriber, and the called subscriber is a prepaid subscriber and
is not in its home network. In order to charge for incoming calls in roaming
to prepaid subscriber, an intermediate signaling layer called as "ModulelS"
between TCAP and SCCP to Handover the received incoming message
(CAMEL InitialDP) fiom MSCISTP to PPS Service (IN Node) via STP in
transparent manner.
[0049] The CAP Layer sends the InitialDP message to the Call
Manager Platform 3 16 for call handing. The Call Manager platform 3 16 then
analyze the CgPN and CdPN and if call is allowed, then the Call Manager
Platform 3 16 will send the IDP to CAP layer to handover the IDP to PPS via
STP. The STP will send the IDP message to the PPS service. The PPS service
then sends the response back to the GSMSSF from where call has been
triggered. The GSMSSF will recogmze the Transaction ID and process the
response received fi-om the PPS service.
[0050] FIG. 6 is a schematic diagram depicting a TCAP message
Relay, according to an exemplary illustration of the present invention. The
figure 6, shows an application acting as a relay between's Message Switching
Centre (MSC) 602 and a standard SS7 network 604. For example,
mCarbon'sSS7 message relay solution is implemented in a third party SS7
Stack Vendor solution. The third Party Stack. provides distributed execution '
of protocol layers to facilitate addition of service layer between any layers.
Module15 and in&oducid between TCAP and SCCP Layers of the third party
SS7 stack to support the SS7 message relay. Huawei and HP OCMP stack
vendor provide this feature inbuilt in their SS7 stack solution.
[0051] ' According to an embodiment herein, mCarbon'sSS7 message
relay solution has been used in the following Telecom VAS services.
1. Call Manager: Relay the IN message (InitialDP) to correct PPS Node for
Call Charging.
2. DND SMS Filter Service: Relay the MT-FSM to serving MSC of
subscriber.
G) ADVANTAGES OF THE INVENTION
[0052] The embodiments of the present invention are adapted to reduce
the unnecessary transactional signaling traffic to and from the network
applications, by forwarding the SS7 message to other network'nodes.
[0053] The embodiments of the present invention is further adapted to
reduce the Signaling Link (SLC) Requirements, reduce the licensing
requirements of Signaling Link, reduce Transaction per second (TPS) of
service which in turns reduce the Application servers (Hardware),Power
Requirements ,Rack Space requirements, Minimize the call setup time by
I
removal of additional hop and reduces the operational cost.
[0054] The foregoing description of the specific embodiments will so
fully reveal the general nature of the embodiments herein that others can, by
applying current knowledge, readily modify andlor adapt for various
applications such specific embodiments without departing from the generic
concept, and, therefore, such adaptations and modifications should and are
intended to be comprehended wihn the meaning and range of equivalents of
the disclosed embodiments. It is to be understood that the phraseology or
terminology employed herein is for the purpose of description and not of
limitation. herefo fore, while the embodiments herein have been described in
terms of preferred embodiments, those skilled in the art will recognize that
the embodiments herein can be practiced with modification within the spirit
and scope of the appended claims.

CLAIMS
What is claimed is:
We Claim:
1. A method of transfemng Signaling System 7 (SS7) messages in an SS7
network, the method comprising:
providing an intermediate signaling layer between aSS7 Transaction
Capability Application Part .(TCAP)layer and a SS7 Signaling .Connection
Control Part (SCCP) layer;
receiving, by the intermediate signaling layer, a first SS7message from the
SCCP layer;
transmitting the first SS7message to the TCAP.layer;
providing, by the TCAP layer the first SS7message to a Call Manager
Platform for call handling ; and
sending, by the TCAP layer a secondSS7message to the SCCP layer through
the intermediate signaling layer.
2. The method of claim 1, wherein the. intermediate signaling layer is 'a
Module 1 5.
3. ,The method of claim 1, wherein the intermediate signaling layer extracts and
stores a plurality of message information elements fi-om the first SS7message
before transmitting the first message to the TCAP layer.
4. The method of claim 3, wherein the plurality of message information elements
extracted fiom the first SS7 message comprises at least one of
calling Party GT Address;
called Party GT Address; and
origTransactionID.
5. The method of claim 1, wherein the Call Manager Platform performs call
handling by:
analyzing a CgPN and a CdPN associated with the first SS7 message to check
if a call is allowed or not;
sending the first SS7 message to a CAMEL Application Part (CAP) layer to
handover the first SS7 to a Prepaid Service (PPS) through a Signal Transfer
Point (STP), if the call is allowed.
6. The method of claim 5, further comprising:
sending, by the PPS, a response back to a GSMSSF from where the call has
been triggered;
recognizing, by the GSMSSF the Transaction ID; and
processing the response received from the PPS service.
I
7. The method of claim 1, wherein sending by the TCAP layer a second SS7
message to the SCCP layer through the intermediate signaling , layer comprises
of I
receiving a second SS7 message from the TCAP layer;
checking if an IDP handover request is present or not in the second SS7
message;
replacing an plurality of information elements associated with the second SS7
message with the pre-stored information elements if the IDP handover request
is present; and
forwarding the second SS7 message to the SCCP .Layer through the
intermediate signaling layer.
8. The method of claim 1, further comprising:
transfening, by the SCCP Layer, the second SS7 message to a lower layer to
send the second SS7 message to an Intelligent Network (IN).
9. The method of claim 1, wherein the Transaction ID of the first SS7 message
and thesecond SS7 message is same.
10. The method of claim 1, wherein the intermediate signaling layer is provided
between the TCAP layer and the SCCP layer of an SS7 stack to support an
SS7 message relay.