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Claims  |
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I claim:
1. In an intelligent network comprising a plurality of telecommunications
switching systems and data base systems, said switching systems and data
base systems being interconnected by a signaling network, a method of
establishing a call comprising the steps of:
sending a query, for data for establishing said call, from one of said
switching systems to a first one of said data base systems;
in said first data base system, determining whether said first data base
system has enough data for responding to said query;
responsive to said first data base system determining that it does not have
enough data to respond to said query, said first data base system sending
a second query to a second one of said data base systems said second query
comprising information to permit .the second data base system to transmit
a response message directly to said switching system;
said second data base system finding data for responding to said second
query and transmitting a first response message comprising said data
directly to said switching system; and
said switching system using said data in said response message for
establishing said call.
2. In an intelligent network comprising a plurality of telecommunication
switching systems and data base systems, said switching systems and data
base systems being interconnected by a signaling network, a data base
system comprising:
means for receiving data from said signaling network;
means for transmitting data to said signaling network; and
processor means, operative under the control of a program and responsive to
a first query message received by said means for receiving, for
determining whether said data base system has enough data for responding
to said query, and if said data base system does not have enough data to
respond to said query, for controlling the transmitting by said means for
transmitting of a second query over said signaling network, to a second
one of said data base systems for finding data and transmitting a response
message comprising said found data for responding to said second query to
a user of said response, wherein said second query comprises information
so that the second data base system can respond directly to a source of
said first query. |
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Claims  |
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Description  |
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TECHNICAL FIELD
This invention relates to data communication arrangements in support of
telecommunication networks and more specifically in support of intelligent
networks.
Problem
A major advance in telecommunication networks of the past decade has been
the introduction of the intelligent network (IN) and the advanced
intelligent network (AIN). Previous telecommunications networks consisted
of switching systems interconnected by transmission facilities. The AIN
enhances the capabilities of such systems by providing, in addition, data
bases called service control points (SCPs) and further by providing
service circuit nodes (SCNs) for customized feature and specialized call
handling including querying telecommunication network customers in order
to obtain additional information for controlling calls. The SCNs are each
connected to an associated switching system and communicate with that
switching system over both audio and data facilities while the SCPs are
connected to the switching systems over a data signaling network. The data
signaling network in most modern systems is a common channel signaling
network using the signaling system 7 (SS7) protocol promulgated by the
Consultative Committee for International Telegraph and Telephone (CCITT)
or by the American National Standards Institute (ANSI).
The intelligent network is used, for example, to route 800 calls. Such
calls lack a dial address that directly allows the telecommunications
network to determine a destination. Instead, upon receipt of an 800
number, a switch of the network equipped to communicate with the SCPs and
therefore designated as a switching services point (SSP) queries an SCP to
obtain information as to where to route the call. For a simple 800 call
the SCP returns a conventional plain old telephone service (POTS) number,
a telephone number that directly identifies the destination, and which can
be used for routing the call to the destination in the conventional way.
For some cases, the initial response from the initially queried SCP does
not provide enough information to establish a call. Under such
circumstances as described, for example, in U.S. Pat. No. 4,924,510 the
initial response from the first SCP is used by the SSP to formulate a
second request to a second SCP identified in the response message from the
first SCP. Such "double dipping" requires four message transmissions to
obtain the information necessary for completing a call.
A problem of the present AIN arrangement is that some of the increasingly
complex services that are being considered today require more and more
exchanges of data between SSPs and SCPs. Such multiple exchanges of data
require the use of scarce resources in the SSPs and further cause
excessive delay in obtaining all the information necessary for
establishing AIN calls.
Solution
The above problem is alleviated and an advance is made over the prior art
in accordance with my invention wherein, in a departure from the prior
art, an SCP is enhanced to recognize situations wherein it needs
additional information from another SCP and directly requests that
information from that SCP by sending an information request message over
the signaling network interconnecting SCPs and SSPs. The second SCP then
sends its response to a user of that response which may be the requesting
SCP or the SSP that originally requested data or even a customer that
directly or indirectly requested data. If the user is the requesting SCP,
this SCP will, directly or indirectly forward data from the response of
the second SCP to the SSP. Advantageously, such an arrangement reduces the
number of query messages that must be transmitted from the SSPs.
In accordance with one aspect of the invention, the first SCP which
requires information from a second SCP transmits enough information to the
second SCP so that the second SCP can transmit a full response directly to
the requesting SSP. Advantageously, such an arrangement requires only
three message transmissions (SSP to first SCP, first SCP to second SCP,
second SCP to SSP) instead of the four (SSP to first SCP, first SCP to
SSP, SSP to second SCP, second SCP to SSP) that would otherwise be
required.
In accordance with one aspect of the invention, the SCP can also send
requests to an SCN, which may include data bases or to another data base
that is part of an SSP or other switching system. Queries from the SCP to
the SCN or to another data base in the SSP are sent transparently through
the SSP that is connected to the SCN so that no processing is required by
the SSP. Similarly, the SCN or a data base of the SSP transmits its
responses directly to the SCP. Alternatively, direct data links between
the SCP and the SCN can be established. Sometimes, the SSP recognizes that
a connection from the customer to an SCN is required and establishes that
connection before or at the same time as it transmits a query to the SCP.
If the SSP has not established such a connection and the SCP recognizes
the need for this connection, the SCP first signals to the SSP to
establish that connection.
In accordance with a specific embodiment of the invention, the data
exchanges between SCPs and between an SCP and an SCN use the so-called
non-call associated (NCA) protocol messages. Advantageously, this
arrangement allows for a smooth transition from the present AIN
configuration to the AIN configuration enhanced in accordance with the
principles of this invention. NCA provides the capability for the
definition of new fields that may be required for some applications of
this invention.
In accordance with another aspect of the invention, the first SCN queries
the second SCN and uses the response data from the second data base to
formulate a complete response to the SSP that queried the first data base.
Advantageously, such an arrangement substantially reduces the amount of
data processing required at the SSP. The data messages between SCPs may be
routed directly through a common channel signaling (CCS) network such as
the SS7 network, or may be routed via the SS7 network and an SSP, acting
as a signal transfer point to relay a data message received from one SCP
or SCN to another SCP or SCN. The SSP can also provide protocol conversion
if the data bases use different signaling protocols.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of an advanced intelligent network and the
communications paths among the elements in accordance with this invention;
and
FIG. 2 is a flow diagram of a program performed in one or more of the data
bases of the intelligent network.
DETAILED DESCRIPTION
FIG. 1 is a block diagram of elements of an advanced intelligent network as
connected in accordance with the principles of this invention. The
elements shown include switching systems, in this case, SSPs 1 and 2, data
base systems SCPs 11, 12, and 13, and SCN 15. The SCPs and SSPs are
interconnected by signaling network 10 which transmits SS7 messages
between SCPs and SSPs or other switching systems connected to the
signaling network. In a departure from the prior art, signaling network 10
transmits messages between SCPs in addition to transmitting messages
between SSPs or between an SSP and an SCP. The SSPs 1 and 2 are
interconnected with each other and with other switching systems of the AIN
by communications network 20. SCN 15 is connected to SSP 2 by both voice
and signaling links. In an alternative arrangement, signaling links of SCN
15 can also be connected directly to signaling communications network 10.
Each of the SSPs 1 and 2 are SSPs equipped to communicate via signaling
network 10 with SCPs 11, 12, and 13. Both are program controlled switching
systems controlled by one or more processors each responsive to a stored
program of the processor. Each of the SCPs also includes a program
controlled processor for analyzing input messages, controlling access to
data stored in the SCP and formulating responsive output messages. In
accordance with the principles of this invention, these output messages
also include querying messages for other SCPs and the processors are
responsive to messages received from other SCPs for formulating a response
message to an SSP. An example of the use of this arrangement is the
following, referred to hereinafter as enhanced 800 service. Suppose that
there is a business which has an 800 number that is meant primarily for
use by customers within a state or within a region of a state (an example
of the latter might be a Chicago metropolitan area 800 number). However,
the business also has a number of important customers and it wishes to
encourage these customers to call using the same 800 number. The business
provides each of these customers with a personal identification number so
that only authorized customers can call the 800 number from out of state.
Subscriber 25 is connected to switching system 2, either directly or, in
the more usual case, through a telecommunications access network. The user
has dialed the 800 number of the business specified above. This number,
along with the caller's directory number, as identified by automatic
number identification (ANI), is transmitted to SSP 2. In response to this,
the switching system 2 transmits a query to SCP 11 which is a basic 800
number response data base. SCP 11 determines that this is not a valid 800
number for a customer from that area (as defined by the numbering plan
area (NPA) of subscriber 25's directory number). However, SCP 11 further
recognizes that this particular 800 number has some customers who are able
to call that 800 number from outside the region. Therefore SCP 11
transmits a message to SSP 2 to request that the customer be connected to
SCN 15 and further that the customer be prompted by SCN 15 to enter a
personal identification number (PIN). The customer enters this PIN which
is transmitted in a message to SSP 2 and thence to SCP 11. SCP 11 does not
contain the data for verifying the PIN and therefore launches a query to
SCP 12. The query is transmitted over SS7 signaling using an NCA message
(e.g., a Transaction Capabilities Application Part (TCAP) message within a
new field) and the message further contains routing information for the
call in case the call can be completed. (This routing information would be
the POTS number of the business.) SCP 12 verifies that the PIN for the
customer identified by the ANI of that customer transmitted in the NCA
message is proper and transmits to switching system 2 the POTS number of
the business along with an indication that switching system 2 may take
further steps to complete the call to that POTS number.
SCP 11 is controlled by a processor 30, operative under the control of a
program 31. The processor is connected to a data receiver 32 for receiving
signaling messages from signaling network 10 and a data transmitter 33 for
transmitting data to the signaling network. Data for the SCP is stored in
data storage 35.
The data bases may be interconnected directly via the signaling network 10,
or it may be more convenient to connect a data base to a switch via the
signaling network, and to use the switch as a signal transfer point to
relay a message to another data base via the signaling network.
FIG. 2 is a flow diagram of actions performed in the data bases in response
to receipt of an 800 call routing request. The routing request is received
(action block 200) and analyzed (decision block 202). If the number is
that of a basic 800 service, then the routing message is returned directly
to the requesting switch in accordance with the teachings of the prior art
(action block 204). If the initial data base recognizes that this is an
advanced 800 call, then a query is sent to the advanced 800 data base
identified in the data stored in the original data base. This query
contains sufficient information so that the advanced 800 data base can
send full routing information directly to the switch. The query is sent in
action block 206 and the advanced 800 data base, responsive to this
inquiry, sends a routing message for the call directly to the switch
(action block 208). Thus, only three messages (SSP to 800 data base, 800
data base to A800 data base, and A800 data base to SSP) are required
instead of the four messages (SSP to 800 data base, 800 data base to SSP,
SSP to A800 data base, and A800 data base to SSP) of the prior art. In
other alternative embodiments, the advanced 800 data base can send a
response to the requesting 800 data base for the latter to return
information directly to the requesting switch.
If the analysis indicates that this is an enhanced 800 call as defined
above then the data base transmits a message to request that the service
node obtain a personal identification number from the caller and return
that PIN to the data base (action block 210). This request is transmitted
to the SSP if no connection has been set up between the calling subscriber
25 and the service node 15 or is sent directly to the service node if such
a connection already exists. The service node will then request the PIN
from the caller and will transmit that PIN to the data base (action block
211). In the preferred embodiment, this transmission is done by means of a
message which has as its destination the data base, so that the only role
of the switch in the transmission of the message is to act as a signal
transfer point to relay the message received from the service node to the
requesting data base or, in alternative embodiments, to provide protocol
conversion. In alternative embodiments, the service node replies to the
switch which then formulates a separate message for transmission to the
data base. In case no PIN has been obtained from the caller, the service
node returns an indication to that effect instead of returning the PIN. In
decision block 212 the data base compares the PIN (if any) received from
the service node with the PIN stored for that caller and that particular
800 destination number. If there is a match, then the data base sends a
query to the 800 data base serving the destination (action block 214) and
that data base sends a routing message for routing the call, in the
preferred embodiment, directly to the requesting switch. In other
embodiments, this data base could send the information back to the
original 800 data base that was queried for that data base to pass on to
the switch.
For this enhanced 800 service, the principles of this invention avoid the
necessity of repeatedly sending intermediate messages (request PIN, PIN
obtained, identity of 800 data base serving destination) to the SSP for
the SSP to process and to initiate another query message. This service is
just one example of a service that can be implemented more efficiently,
with less processing load on the SSP and shorter call set-up times, in
accordance with this invention.
If either no PIN has been obtained or there is no match, then a routing
message to route the call to an announcement ("your call cannot be
completed" or equivalent) is returned to the switch (action block 218).
It is to be understood that the above description is only of one preferred
embodiment of the invention. Numerous other arrangements may be devised by
one skilled in the art without departing from the scope of the invention.
The invention is thus limited only as defined in the accompanying claims.
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Description  |
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