Note: Descriptions are shown in the official language in which they were submitted.
- WO 96/38009 2 1 9 4 7 8 5 PCI'IUS96/05347
RADIOTELEPHONE SW~TCHING SYSTEM AND METHOD OF
PROVIDING RADIOTELEPHONE SERVICES
FIELD OF l~IE INVENTION
The present invention relates generally to communication
systems, and more particularly, to switching systems for
radiotelephone communication systems and to a method of providing
services in a radiotelephone communication system.
1 0
BACKGROUND OF THE INVENTION
Communication systems are well known and consist of many
types including land mobile radio, cellular radiotelephone, personal
15 communication system (PCS), and other communication system types.
In, for example, cellular radiotelephone communication systems, a
number of communication cells, serviced by base transceiver stations
(BTS), are typically linked to a base station controller (BSC). The BSCs
are, in turn, linked to mobile switching centers (MSCs) which provide
2 0 a connection between the cellular radiotelephone communication
system and the public switched telephone network (PSTN) as well as
interconnection of various cellular radiotelephone communication
systems. Mobile communication units operating within the
communication cells utilize radio communications to transmit and
2 5 receive signals with the serving BTS. The signals are processed by the
BTS, BSC and MSC to complete a communication transaction with a
land line telephone user connected to the PSTN or to another mobile.
The MSC of a radiotelephone communication system is typically
a complex system integrating telephony switching elements with
3 0 radiotelephone communication system specific aspects such as
signaling, control, etc. These systems are complex to build, to maintain
~ and to upgrade. For example, the hardware and software architecture
of such radiotelephone switching systems require subscribers services
- functionally integrated into the proprietary operating software of the
3 5 MSC. To add to, upgrade or otherwise change the ability of the MSC to
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provide subscriber services requires changes in the MSC operating
software, usually at considerable expense and development time.
Because of this, the addition of software features for providing
enhanced services to the system subscribers is severely limited.
Recently, it has become known to construct wireline
communication systems using an intelligent network architecture.
Such an architecture is described in Intelli~ent Networks, Jan Thorner,
Chpt. 2, Artech House 1994. The essence of a communication system
constructed in accordance with intelligent network technology is
centralized service control typically provided by a service control point
(SCP) processor(s). Traditionally, service control was implemented at
the switching system similar to the above-described MSC. The
advantage of an intelligent network architecture implementation is
that software, in the form of service logic modules (SLMs), required to
provide services within the communication system operate on the
SCP, i.e., a stable platform that seldom changes. To add new services or
change existing services, only the parts of the SLMs that are unique to
the service require design or revision. This greatly reduces the time to
develop and implement new services or to adapt or upgrade existing
2 0 services.
Unfortunately, these known intelligent network
implementations have not proven well suited for wireless
communication systems such as radiotelephone communication
systems. For example, in wireline systems the subscriber, i.e., the
2 5 telephone system customer, has a fixed location and appearance to a
servicing wireline switch. The provisioning of triggers, i.e., points in
the call processing indicating initiation of a special service or feature at
an SCP, are easily implemented in the switch servicing the subscriber.
However, in radiotelephone communication systems, subscribers may
3 0 roam from system to system. Therefore, the triggers for the subscriber
would have to be redundantly provisioned in multiple systems.
Additionally, the known intelligent network implementations require
intelligent peripherals (IPs, hardware which implement certain
specialized functions) to be directly controlled by the switch.
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The ability of radiotelephone system operators to win new
subscribers will turn on their ability to provide new services quickly
and cost effectively. Therefore, the success of radiotelephone system
manufacturers will turn on an ability to provide systems to which new
5 services may be easily added and/or upgraded. Thus, there is a need to
adapt intelligent network technology to radiotelephone
communication systems overcoming the limitations of such
technology as applied to wireline communication systems.
1 0 BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is block diagram of an exemplary cellular radiotelephone
communication system which may incorporate the present invention;
FIG. 2 is block diagram of a radiotelephone switching system in
accordance with a preferred embodiment of the present invention;
FIG. 3 is, in accordance with a preferred embodiment of the
present invention, a functional block diagram of the service control
point processor of FIG. 2;
FIG. 4 is a bubble diagram illustrating the functional inter-
2 0 relationship of elements in accordance with a preferred embodiment of
the present invention of the service control point processor of FIG. 2;
FIG. 5 is a block diagram illustrating service action trigger
dispatching in accordance with a preferred embodiment of the present
lnvention;
2 5 FIG. 6 is a block diagram illustrating effective subscriber service
provisioning determination in accordance with a preferred
embodiment of the present invention;
FIG. 7 is a block diagram illustrating effective subscriber service
status determination in accordance with a preferred embodiment of the
3 0 present invention;
FIG. 8 is a block diagram illustrating digit pre-translation in
accordance with a preferred embodiment of the present invention; and
FIG. 9 is a bubble diagram illustrating functional inter-
relationship of elements of the service control point processor of FIG. 2
3 5 in accordance with a preferred embodiment of the present invention.
wo 96/38009 2 1 9 4 7 8 5 F~ 5'~05347
DETAILED DESCRIrrION OF THE PREFEI~RED EMBODIMENT~S)
The present invention provides a radiotelephone switching
5 system and a method of providing subscriber services within a
radiotelephone communication system. In a preferred embodiment of
the present invention, a switch, typical of switches presently used in a
telephone communication systems, is coupled to a processing platform
for enhancing its functional capabilities. The processing platform
l 0 includes a trigger manager for accessing a plurality of service modules
designed to provide services, typically provided within proprietary
processing software of the MSC, to the subscribers/users of the
radiotelephone communication system. The trigger manager provides
for provisioning of services and intelligent dispakh of triggers within
l 5 the switching system. Additional services and features may be added to
the radiotelephone communication system at any time by simply
adding additional service modules. By providing the trigger manager
numerous service modules may be developed and implemented
independent of any proprietary processing associated with the switch.
2 0 Moreover, redundant provisioning of services in multiple systems is
not required to provide seamless services to roaming subscribers.
Referring to FIG. 1, the radiotelephone communication system
100 includes a plurality of BTSs 21-23 serviced by BSCs 31-33 as
shown which makes up the base station system (BSS) 50. BSCs 31 - 33
2 5 are coupled to an MSC 60 which in turn is coupled to the PSTN 70.
Mobile communication units (one of which is shown as mobile 80)
operate in communication cells serviced by BTSs 21 - 23 and
communicate with BTSs 21 - 23 via radio links in a known manner.
Calls originating with or terminating at mobile 80 are processed
3 0 through MSC 60 to either a wireline telephone customer linked to
PSTN 70 or the other radiotelephone communication system users
serviced by MSC 60 or other MSCs (not shown).
With reference to FIG. 2, MSC 60 includes a switching system
(switch) 110 coupled to a service control point (SCP) processing
3 5 platform 112 via signaling links 114. Switch 110 may consist of a
w096t38009 2 1 ~ 4 7 85 P~ /05347
switching system commonly employed in radiotelephone
communication systems, or may comprise a Class 5 telephony switch
. incorporating intelligent networking (IN) capabilities. SCP 112 may be
any suitable processing platform. Signaling between SCP 112 and
5 switch 110 is preferably according to a standard protocol such as lnterim
Standard (IS - 41) published by EIA/TIA, or the distributed mobile
exchange (DMX) protocol and enhanced versions thereof available
from Motorola, Inc., Cellular Infrastructure Group, 1501 W. Shure
Drive, Arlington Heights, Illinois 60004. Intelligent peripherals (IPs)
1 0 130 are also linked to switching system 110 via voice/data trunk 116
and to processing platform 112 via signaling link 118. Signaling link
118 in a preferred embodiment is a transmission control
protocol/internet protocol (TCP/IP) based voice response interface
(VRI) protocol, while voice/data trunk 116 is any voice/data trunk
1 5 including T1, fiber optic, etc.
Referring to FIG. 3, the elements of SCP 112 are shown, generally
in hierarchical relationship, to include a core processor 120 coupled to a
call model processor 122 and an interface 124. SCP 112 further includes
a trigger manager 126 coupled to both call model processor 122 and
2 0 interface 124. Coupled to both trigger manager 126 and interface 124 are
a plurality of service modules 128 which provide the functions for
implementing subscriber services in radiotelephone communication
system 100.
With continued reference to FIG. 3, core processor 120 is coupled
2 5 directly to a plurality of IPs one of which is shown at 130 via signaling
link 118 and by voice/data trunk 116 to switch 110. Core processor 120
is also coupled to a database system 132 which stores, among other
things, the radiotelephone communication system and subscriber
provisioning and status information as will be described. In addition
3 0 to interfacing with IPs 130, switch 110 and database 132, core processor
120 provides additional functions such as transaction context
management and transactions capabilities applications part (TCAP) as
provided in the signaling system 7 (SS7) protocol for routing data.
Call model processor 122, in the preferred embodiment, is a
3 5 finite state machine which maps the interface protocol on link 118, i.e.,
W0 96138009 2 1 9 4 7 8 5 PCItUS96/05347
DMX call processing messages, into the Bellcore Advanced Intelligent
Network (AIN) call model. At certain states, processing is suspended
by call model processor 122 and trigger manager 124 is activated for
providing spe~iAli7e~1 services or features. Trigger manager 124
provides for implementing subscriber services through intelligent
instruction and dispatch of event triggers and service action triggers to
the SLMs 128.
FIG. 4 shows the inter-relationship of functional elements
within switching system 110 for providing call processing. Central is
1 0 the call process related function 200 which as noted above in a
preferred embodiment is the Bellcore AIN call model. Several trigger
enhancements to the Bellcore call model are made possible through
implementation of the present invention and are described below.
Additional elements are the digit pre-translation function 202 and non-
1 5 call process related function 204.
Also shown in FIG. 4 are trigger event dispatch function 206,
service action dispatch function 208 and determine service status
function 210 which are provided and administered by trigger manager
124. Trigger dispatch event function 206 is responsible for converting
2 0 an event trigger into a prioritized list of potential service actions. Theservice action list is generated from the service definition table 214
which is accessed in an associative manner with an event trigger
identification (ID) and is communicated to service action dispatch
function 208.
2 5 With reference to FIG. 5, service action dispatch function 208
provides for dispatching service action triggers, i.e. dispatching triggers
to SLMs, based upon the service action list, information in the service
switch table 216 and effective subscriber service indicators. This
information provides service action dispatch function 208 with a basis
3 0 for determining whether a service action trigger should be dispatched,
i.e., whether the service is provisioned, its status is active and the
service action is invoked. In the preferred embodiment, service action
triggers are dispatched according to the criteria contained in Table I
below. The effective subscriber service indicators include effective
3 5 subscriber provisioning indicators and effective subscriber service
W096/38009 2 1 q4 7~5 PCI/US96/05347
status indicators which are generated by determine service status
function 210. Service action dispatch function 208 also utilizes service
scope, service ID and service action ID information for identifying SLM
triggers within service switch table 216. Service action dispatch
5 function 208 continues to dispatch service actions, i.e., SLM triggers,
until the service action list is exhausted or an SLM returns a trigger
response other than continue. Upon exhausting the service action list
or receiving an other than continue trigger response from an SLM,
service dispatch function provides a trigger response to call process
l 0 function 202. This trigger response is either continue, if all service
actions on service action list are exhausted or the non-continue trigger
response from an SLM.
In the preferred embodiment, the service definition table
contains service scope, service ID, service name, service mnemonic,
1 5 service priority, service state handling, and trigger event list fields. Theservice scope field defines the level at which the service is provisioned.
That is, if
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wo 96138009 2 ! ~ 4 7 8 5 PcrluS96/05347
the service is a system level service applicable to all subscribers or a
subscriber level service provisioned individually to all subscribers.
The service ID, service name and service mnemonic fields provide
means for identifying a particular service. The service priority field
5 contains data which provides for determining an order in which
service actions are dispatched in response to a common event trigger.
The service state handling field contains data used to specify the type of
state handling the service employs, either active or variable. The
trigger event list contains the trigger events which a particular service
I 0 need for operation. The trigger event list also contains the event ID
and service action ID which may be one of the following: Activation,
Deactivation, Registration, Erasure, Interrogation, Invocation, Service
Specific 1 or Service Specific 2. In operation, trigger dispatch function
206 uses the event trigger ID to identify the service actions associated
1 5 with a particular event trigger. The service priority data is then used to
order, in a prioritized fashion, the service actions into the potential
service actions list which is then communicated to the service action
dispatcher 208.
Determine service status function 210 calculates the effective
2 0 subscriber service provisioning and status indicators which are
required for proper support of SLM execution and call processing.
With reference to FIG. 6, feature provisioning information is combined
from a field of the system profile 230 and a field of the subscriber profile
232 to determine an effective subscriber service provisioning indicator
2 5 240. In a preferred embodiment, duplicate provisioning of subscriber
features in both subscriber profile 232 and in a feature package table 234
allows for continued use of feature packages. System profile 230
provides a centralized means for provisioning services on a system
wide basis, while subscriber profile 232 and feature package table 234
3 0 provide means for provisioning services on a per subscriber basis.
Exemplary effective subscriber provisioning indicators are indicated in
Table II above.
Next, with reference to FIG. 7, subscriber service status
information is combined to provide an effective subscriber service
3 5 status indicator 242. In a preferred embodiment such information
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includes subscriber service status information from a field in the
system profile 232, per call subscriber service status information from a
field in the subscriber profile 234, subscriber service status handling
information from a call occurrence field 236 and subscriber service
status indicators from service definition table 214. Exemplary effective
subscriber service status indicators are indicated in Table III.
In response to a service action trigger from service action
dispatch function 208, the SLMs perform various functions in support
of subscriber services and features. These include causing a forward or
1 0 a redirect of a terminating call, paging a mobile subscriber, initiating
call waiting, etc. Under normal conditions an SLM will provide a
trigger response of continue, which indicates that the call process
function 202 should continue without regard to the SLM processing, or
another response instructing the call process function 202 to take some
1 5 action with respect to the current call. A failure response may also be
returned indicating that a general failure occurred during processing of
the service action.
With reference once again to FIG. 4 and further reference to FIG.
8, pre-translation function 202 is also provided within switching
2 0 system 110. Pre-translation function 202 converts the subscriber
originating class of service (OCOS) to a dialing plan 252 through the use
of an OCOS conversion table 254. The subscriber OCOS is retrieved
from a field within subscriber profile 232. The dialing plan ID and any
collected digits, i.e., digits input by the subscriber in addition to the
2 5 requesting a service, are matched to an entry in the pre-
translation/dialing plan table 252. The entry in the table identifies
either a trigger event ID which is communicated to trigger event
dispatch function 206 or a service action which is communicated to
service action dispatch function 208 for appropriate action.
3 0 SCP 112 through trigger manager 126 further provides for
maintaining statistics on services used 260, and one messaging with
switch 110. This is accomplished through dispatch of appropriate
triggers to statistic SLMs for updating theses statistics.
As will be appreciated, by adding additional triggers within the
3 5 call model, and corresponding SLMs, numerous additional services
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and features may be added to switching system 110 with minimal
investment and engineering effort. This is illustrated in FIG. 9 where
several additional triggers have been added to call process function 202,
each shown separately in FIG. 9 as 1202, 2202, 3202, 4202 and 5202.
Triggers 1202 and 2202 provide for call origination and termination,
respectively, in accordance with the Bellcore call model. Trigger 3202
provides for
autonomous registration of the mobile subscriber in radiotelephone
communication system 100. Upon receipt of a I_ROAM_UPDATE
l 0 message, call process function generates an autonomous registration
trigger event which is communicated to trigger event dispatch function
206 of trigger manager 124. In accordance with a preferred embodiment
of the present invention, trigger manager 124 will cause the dispatch of
service actions to the appropriate SLM for registering the mobile
1 5 subscriber in radiotelephone system 100. If registration is successful,
the mobile subscribers status is updated in the subscriber status table
238 by the SLM and a continue is returned as the trigger response.
Similarly, such additional services as feature update 4202 and remote
feature update 5202 are implemented via the addition of appropriate
2 0 triggers within call process function 202 and SLMs.
As will be appreciated from the foregoing, the advantages of
intelligent network technology are made applicable to radiotelephone
communication systems through the introduction of trigger manager
124. Trigger manager 124 provides for prioritization and provisioning
2 5 of subscriber services on a per subscriber basis and without requiring
redundant provisioning in multiple systems. Moreover, subscriber
features and services are easily added to a system without extensive
costs and delays for development.
We Claim:
