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Connection Manager for Telecommunications
Field of Invention
The present invention relates generally to telecommunications, and more
specifically, to a system and method of managing telecommunication
connections.
Background of the Invention
The present invention relates generally to telecommunications and
telecommunications systems which includes networks such as the public switched
telephone network, Internet, cellular telephone systems, satellite
communications,
local area networks (LANs) and wide area networks (WANs). The interconnections
which make up these networks may consist of a variety of media including
optical
fibre, wireless or hardwired electrical connections. As well, communications
over
these networks may be executed using a variety of protocols.
One major design aspect of communications in any of these networks is
connection management, often referred to as "call processing" in the telephony
world. Connection management is the process of setting up connections,
managing
connections in progress, and tearing them dawn. in telephony, for example:
~ setup involves: detecting dialled digits, deternnining where the telephone
being
called is located, determining whether the called telephone is in use, and
ringing it;
managing a call in progress involves: detecting "flash" signals and handling
"call waiting" processing; and
~ teardown involves: releasing communicationtrunks and forwarding the billing
record to the party being charged for the service.
Many telecom features, such as call-waiting and busy-call return, are
primarily issues
of connection management.
Connection management exists in the Internet, too. Internet protocol (IP) is
in
principle "connectionless" as each data packet includes a destination address
and
may arrive at its destination via a different route thane other data packets
transmitted
during the same session, between the same calling party and called party.
However,
most IP communications are performed using a "virtual connection", such as
Transmission Control Protocol (TCP) which is often used over IP. While 1P
handles
the actual delivery of the data, the TCP keeps track of the individual data
packets,
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creating a virtual connection which lasts the life of the communication
session.
Similarly, other Internet applications such as chatting and Internet games may
apply
a similar concept, using protocols such as Internet Relay Chat (IRC) which
uses IP as
a pipe.
Regardless of whether communication within a network is considered
connection-less or connection-based; some manner of connection management must
be performed in order to administer communications within the network. In
fact,
when a telephone call is made today, the voice signal may be turned into data
and
follow a "connectionless" route anyway.
Connection features are at present complex to develop. Connection features
interact with each other, and this feature interaction makes development and
deployment of features difficult. As a simple example, "call waiting" is
inconsistent
with "voice mail on busy" and with "busy call return" because these features
all
specify different behaviours when the called line is busy. Compromise
behaviours
can be arranged when the features are inconsistent, but these situations must
be
specifically -considered.
Features interact in particularly undesirable ways when different parties to a
call have different interests. "Call forwarding", for example, involves one
party using
another's telephone to receive incoming calls, and the party to whom the call
is
forwarded may wish to control this.
Because new connection features are difficulil to develop, telecom systems
are slow to react to market needs. New media and new applications of
communications are making feature development yet more complex.
Feature development is already difficult for the simple application of
conversation over voice telephones. As new media such as videophone, typed
messaging, shared files and whiteboards, and new applications such as distance
learning, Internet Relay Chat, networked document preparation, meeting
management and Internet gaming, develop, the problem is becoming even more
severe. This problem will grow even greater as media are mixed, for example
when
voice-text conversion permits a mixture of media in a conversation, and when
expectations develop for features from one domain to be mapped into another,
as
when customers expect a feature similar to Gail-waiting to apply in
videoconferencing
or Internet gaming.
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As well, even for a single application, different users may have different
needs, for example, requiring different degrees or forms of encryption. This
makes
the development of communications applications slo~nr due to the complexity of
handling many cases.
Telecommunications systems, such as those for telephony and the Internet,
are composed of terminal equipment such as telephones or personal computers,
an
access network such as a telephony focal loop or a radio link, and a backbone
network such as the public switched telephone network (PSTN) or the intercity
data
networks. Although the needs of users at the terminals are very varied, the
backbone networks must handle highly standardized toads in order to operate
reliably
and efficiently.
Telecommunications systems need to process the data flowing through in
compiex ways, often with processing occurring on computer systems separated
both
geographically and administratively. Many communications paths are
simultaneously
active, and the processing applied to the various flovvs of data changes
frequently
and in a wide variety of ways. The software needed to control these computer
systems is generally large, complex and difficult to change.
When the data flowing through he system represents voice, such as in a
modern digital telephone network, special processing must be applied to
implement
such features as three-way or mufti-way calling, voice-mail, voice recognition
and
authentication, calf waiting, encryption, voice coding and dual-tone mufti-
frequency
(DTMF) detection. For data applications in general, such as electronic mail,
remote
computing, file transfer between computers or Web browsing, there are needs
for
security functions such as firewails and encryption as well as datastream
functions
such as traffic shaping, error handling, prioritization, caching, format
translation and
multicast.
In voice telephony, services are implemented by having large computer
programs running on centralized switches which interrogate local and
distributed
databases. The local databases specify which features are enabled on a given
line,
the switch softvvare interprets these feature lists and implements the switch
behaviour, and the switch software also interrogates the distributed databases
via
Common Channel Signaling System No. 7 (SS7) queries. SS7 is a global standard
for telecommunications that defines the procedures and protocol by which
network
elements in the public switched telephone network (PSTN) intercommunicate
control
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messages for basic call setup, management, and tear down, as well as for
special
intelligent or database services such as local number portability (LNP), toll-
free
(8001888) services, arid enhanced call features such as call forwarding,
calling party
namelnumber display, and three-way calling.
In PSTN, the connection manager is fixed by the services provided by the
local exchange carrier, which in turn may only function within the bounds of
the SS7
protocol. Therefore, calls can not access the switches except in a limited
way, and
new features can not be added by outside parties.
Telephony features; such as call forwarding, may only be implemented by
adding code to the programs running the switches or by adding specialized
hardware
to the telephony network. The features available to particular users are
defined in the
local databases accessed by the switch software, and adding a new type of
feature
may involve changing these databases together with all of the switch software
that
uses them, and may also involve purchasing and installing new types of
hardware in
the network. Specialized software is also used to check the consistency of the
features assigned to a particular user: For example, call-waiting and
call-forward-on-busy features define different behaviours for the same event,
a busy
receiver; so both features may not be assigned to a user simultaneously.
In general, signal processing for telephony is done in hardware specialized
for
each type of task, for example, there is different hardware for tone decoding
and
conferencing. This limits the speed with which new features can be introduced
since
new hardware has to be designed, tested, manufactured and deployed. The fixed
assignment of tasks also makes it impossible to share loads between different
types
of hardware, for example to use idle tone-decoding hardware to help with an
overload
of voice-conferencing.
Changes to existing telecommunication networks are therefore very
complicated to make. There is a rigid model and hardware structure is
difficult to
extend. Therefore, existing teicos can not offer nevi features such as high
quality
voice. As well, existing telco's take a long time to k>ring such features to
market.
The complexity of present telecommunications systems software, and the
extensive interactions between its software components, makes the development
of
new features very difficult. As well, telecomm services have traditionally
been
provided by large monopolies who employed proprietary equipment that only they
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had access to. Another complexity is that new services had to be backward
compatible to handle their existing clientel.
Software development is therefore limited to b "closed" group of trusted
developers, which reduces the talent pool available and shuts out developers
with
new ideas for niche markets.
Traditional telecomm does not consider differentiation, but focuses on
provision of single services. Therefore, telecomm providers would not be
encouraged to offer varied services at a cost reduction to users, for example,
reduced quality of voice telephony on Christmas Dayr, simply to provide
additional
connections or reduced cost. As well, small niche markets have gone unserved
completely as the cost of developing and implementing the additional products
does
not net sufficient profts.
Users can exercise a small degree of control over their telecommunications
by use of software running on their personal computers (PCs). For example,
there is
currently a Telephony Applications Programming interface (TAPI} that allows
software running on a general-purpose computer to control the switching
decisions of
a type of switch known as a private branch exchange (PBX).
An application programming interface (API) converts a series of comparatively
simple and high level functions into the lower levei instructions necessary to
execute
those functions, simplifying use of an operating system. Using Windows APIs,
for
example, a program can open windows, files, and message boxes, as well as
perform more complicated tasks, by executing single instructions. Therefore,
TAPI
consists of a collection of specialized subroutine calls that allow a user to
set up and
tear down circuits connecting particular physical devices, including telephone
sets
and servers for functions such as voice-mail. It also allows the user to
define how the
system should respond to events such as hangups.
A system known as Parlay implements a telephony API that can be used to
control the central office telephone switches owned by large telephone
companies.
This is similar in concept to the use of a telephony API to control a PBX, but
security
concerns are of prime concern because of the number of telephone users who
would
be inconvenienced by a failure. Switch owners will not allow user access that
may
effect the reliability of their networks, therefore the degree of control that
a user may
exercise over his communications, is very limited.
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Parlay, TAPI and similar systems permit third parties a degree of control over
how telephone switches interconnect end users and specialized equipment such
as
voice-conferencing servers, but do not allow third parties to add new features
such as
encryption or voice coding. They are also unable to describe the handling of
Internet
traffic, and so it is necessary for a distinct system to be used to handle
such functions
as routing Internet browsing data through computers acting as security
firewalls.
Networks for telephony and data transmission have developed separately, but
the economic rationale for having distinct physical networks is very weak and
therefore the technologies are converging. They appear to be converging on a
model
closer to that for data than that far telephony, partly because of its greater
generality.
The dominant data network is currently the Internet.
The Internet is a cannectionless network service, in that a single
communication may be broken up into a multitude of data packets that follow
different
paths in flowing between the same source and destination, though as noted
above,
various protocols exist which create "virtual connections'. Traditional
telephony in
contrast, establishes a single path that all of the data in the communication
follow.
Regardless, call management of Internet applications is generally done by the
software running at the endpoints, and the IP network is treated merely as a
conduit
for transfer of the data packets between the two points. The routers in the IP
network
merely index internal routing tables using the address in the data packet so
that they
knorn~ how to forward it, and do not generate data for either of the
endpoints, or react
to instructions from either of the endpoints. The Internet itself may be
envisioned as
a series of routers interconnected by an Internet backbone network designed
for
high-speed transport of large amounts of data. Users may access the Internet
using
personal computers in a number of manners including modems connected to the
Public Switched Telephone Network, and set top boxes connected to existing
telephone or television cable networks:
Communications over the Internet can take the form of various protocols, aver
a variety of physical transfer media. A protocol is a set of conventions or
rules that
govern transfer of data between hardware devices. The simplest protocols
define
only a hardware configuration while more complex protocols define timing, data
formats, error detection and correction techniques and software structures.
Socket mechanisms are widely used to describe connections between
applications programs running on operating systems such as UNIX and Windows.
It
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can be used to set up connections between applications programs running on
different computers, such that packets of data are passed between them across
such
networks as an Ethernet or the Internet. When using a socket to communicate
with a
process on another computer, the programmer defines one side of a
communication
but must rely on the administrators of the other computer to have set up the
other
side.
Sockets typically use the Internet Protocol (IP) and can further be set up to
use either the Unreliable Datagram Protocol (UDP} which sends packets without
checking to see if they have been received, or the Transport Control Protocol
(TCP)
which will retry until it receives a confirmation of receipt. Telephony
applications
typically use UDP, because data that does not arrive on time is of no value,
while file
transfer programs typically use TCP so that accurate delivery is assured. The
user is
generally required to choose between these two mechanisms to specify handling
of
error conditions in packet delivery. Just as for telephony, it is difficult to
add
encryption or signal processing features to the handling of an IP siream.
The key advantages of a protocol like IP are i:hat it allows a large network
to
function efficiently and that it offers a standardized means by which
applications
software can use that network. Disadvantages are that it does not allow
specification
of processing to be pertormed on data streams and that it does not accurately
specify
requirements on quality of service.
The Internet generally will not let a user run an applet on a node or server.
This (imitation is due to the architecture of the Internet which is based on
the
international OSl (Open Systems Interconnection) standard. The OSI standard
describes communication systems using a seven layer model, each layer being
operable to perform certain functions. Although OSI is not always strictly
adhered to
in terms of keeping related functions together in a well-defined layer, most
telecommunication products make an attempt to place themselves in relation to
the
OSl model. The OSI standard is not likely to change dramatically, nor is the
fnternet's use of the standard, so the Internet will not likely become an
active
component in the provision of telecommunication services.
However, some protocols such as RSVP do exist, which set tags and
priorities which can influence the routers a little, but not much. The
resource
reservation protocol (RSVP) is an extension to IP that permits specification
of quality
of service at a technical level, in terms of parameters such as data rates and
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latencies. It has had limited acceptance due to the complexity it adds to
backbone
networks and the need for their switching hardware to be updated.
Therefore, typical software applications operating over the Internet look at
the
fnternet as simply a transport network without any processing capability, and
all
functionality is placed at the calling and called party locations.
Implementations of
voice over Internet, for example, have software at tine user's computer that
acts as
the interface with the user, converting voice to data packets for IP
transmission, and if
desired, may generate dial tones and DTMF tones simply as feedback for the
benefit
of the user. These tones do not pass over the Internet as all Internet
communications
are simply data packets with the destination attached.
Asynchronous Transfer Mode (ATM) networks use standard protocols for
addressing packets of data and setting up connections, as do IP and TGP
respectively. ATM networks have typically been deployed in the core of
backbone
networks because of the high speeds at which ATM equipment operates, and their
capabilities have not been directly visible to end users. Because ATM routers
are not
directly accessible and because of the complexity of their mechanisms for
describing
quality of service (QoS), these mechanisms have not been used by applications
software.
Besides the IP and ATM networks mentioned above, there are other data
networks such as Frame Relay and Ethernet. As well, the PSTN may also be used
to
carry data, for example using trellis coding which maps digital data onto an
analogue
signal. Variants are also evolving of each major type of network, and
engineering
differences between implementations of these networks result in different
performance. The complexity induced by this variety makes it difficult for
users and
application software to exploit all the networks available, and to exploit any
to its
fullest extent.
As explained above, existing data or voice networks are complex and it is
either difficult or impossible for users to add new functionality to them. The
convergence of these forms of networks, and the demand for services to move
seamlessly between networks will make the task of providing new services in a
mixed
network environment even more difficult.
The access networks known in the art have severe limitations that came from
their having been designed for narrovvly defined telecommunications
applications,
such as telephony or file transfer. Therefore, an invention which allows an
access
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network #o have the sophisticated functionality necessary for a mixture of
telecommunications services is required.
There is therefore a need for a ,method and system of connection
management for telecommunication systems that is addresses the complexity of
such
networks and provides an open, scalable and flexible architecture for the
provisions
of new services. This design must be provided with consideration for the
pervasiveness of the existing infrastructures.
Summary of the invention
It is therefore an object of the invention to provide a system and method of
managing telecommunication connec#ions that improves upon the problems
outlined
above.
One aspect of the invention is broadly defined as a connection management
system for telecommunications comprising: a first user terminal; a second user
terminal; a telecommunications network interconnecting the first user terminal
and the
second user terminal; and modular connection management software including a
connection management software proxy for each of the first user terminal, the
second
user terminal and the telecommunications network, each of the connee#ion
management software proxies being operable: to execute on the system; and to
provide the functionality to represent its owner's interests in managing the
telecommunications connec#ion.
Another aspect of the invention is defined as a method of connection
management for a telecommunications system, executing on a telecommunications
server, comprising the s#eps of: interconnecting a first user terminal and a
second
user terminal; and executing modular connection management software including
a
connection management software proxy for each of the first user terminal, the
second
user terminal and the telecommunications server, each of the connection
management software proxies being operable: to execute on the
telecommunications
system; and to provide the functionality to represent its owner's interests in
managing
a telecommunications connection.
Another aspect of the invention is defined as a telecommunications server for
a telecommunications system comprising: interconnecting means for
interconnecting
a first user terminal and a second user terminal; and modular connection
management means including a connection management software proxy for each of
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the first user terminal, the second user terminal and the telecommunications
server,
each of the connection management software proxies being operable: to execute
on
the telecommunications system; and to provide the functionality to represent
its
owner's interests in managing a telecommunications connection.
An additional aspect of the invention is defined as a computer data signal
embodied in a carrier wave, the computer data signal comprising a set of:
machine
executable code being executable by a computer to perform the steps of:
interconnecting a first user terminal and a second user terminal; and
executing
modular connection management software including a connection management
software proxy for each of the first user terminal, the second user terminal
and the
telecommunications server, each of the connection nnanagement software proxies
being operable: to execute on the telecommunications system; and to provide
the
functionality to represent its owner's interests in managing a
telecommunications
connection.
A further aspect of the invention is defined as~ a computer readable storage
medium storing a set of machine executable code, the set of machine executable
code being executable by a computer server to pertorm the steps of:
interconnecting
a first user terminal and a second user terminal; and executing modular
connection
management software including a connection management software proxy for each
of the first user terminal, the second user terminal and the
telecommunications
server, each of the connection management software proxies being operable: to
execute on the telecommunications system; and to provide the functionality to
represent its owner's interests in managing a telecommunications connection..
Brief Description of the Drawings
These and other features of the invention will become more apparent from the
following description in which reference is made to the appended drawings in
which:
Figure 1 presents a schematic diagram of an exemplary telecommunications
system
in a broad embodiment of the invention;
Figure 2 presents schematic diagram of an exemplary mixed-network
telecommunications system in an embodiment of the invention;
Figure 3 presents schematic diagram of a telecommunications system in the
preferred embodiment of the invention;
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Figure 4 presents a block diagram of a high level overview of an established
connection in a preferred embodiment of the invention;
Figure 5 presents a block diagram of how a Connection Object establishes
contact
with a user in a preferred embodiment of the invention;
Figure 6 presents a block diagram of how a Connection Object is established in
a
preferred embodiment of the invention;
Figure 7 presents a block diagram of how a Connection Object establishes a
negotiation in a preferred embodiment of the invention;
Figures 8A and 8B present a flow chart of a process for connection management
in
a preferred embodiment of the invention;
Figure 9 presents a block diagram of a call-processing state machine
responsible for
initiating calls according to a conventional dial-tone model in an embodiment
of the invention;
Figure 10 presents a block diagram of a call-processing state machine with
detailed
billing in an embodiment of the invention; and
Figure 11 presents a block diagram of a call-processing state machine with
multiple
independent bills in an embodiment of the invention.
Description of the Invention
A system which addresses the objects outlined above, is presented as a block
diagram in Figure 1. This figure presents a block diagram of an exemplary
connection management system 10 for telecommunications in which a connection
may be established between a first user terminal 12 and a second user terminal
14
interconnected via a telecommunications network 1fi. The phrase "terminal" is
used
generally in the art to describe any suitable manner of user interface in an
audio,
video, data or other similar fashion, and may include: any type of
telecommunication
device including telephone, personal computer, cellular telephone, pager, fax
machine of other device as known in the art.
The connection itself is managed by modular connection management
software which includes a connection management software proxy for each entity
in
the system. In this case there are three entities with three corresponding
proxies.
The first user's proxy 18 is shown to reside on the first user terminal 12 and
the
second user's proxy 20 and telecommunications nei:work proxy 22 are shown to
reside on the telecommunications network 16 but as will be explained, they
rnay
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reside in other locations. Each of these connection management software
proxies is
operable to execute somewhere on the telecommunications system and to provide
the functionality needed to represent its owner's interests in managing the
telecommunications connection.
In this example, the first user's proxy 18 is shown to reside on the first
user
terminal 12 which requires first user terminal 12 to have the functionality to
execute
the first user's proxy 18. The first user terminal 12 may, for example,
comprise a
microphone and speaker connected to the sound card of a personal computer, or
a
smart telephone with a built-in operating system. Respectively, the first
user's proxy
18 could execute on the microprocessor in the personal computer or on the
digital
signal processor within the smart telephone.
The second user's proxy 20 is shown to reside on the telecommunications
network 16 which may be necessary if the second user terminal 14 does not have
the
functionality to support the software proxy. The second user terminal 14
could, for
example, be a standard telephone or cellular telephone. Nonetheless, the
second
user is still given symmetric treatment along with the other entities in the
system, by
having a proxy provided for it which executes on the telecommunications
network 16.
In such a case, the second user's proxy 20 would ge~neraliy be selected from a
schedule of "generic proxies" by the telecommunicai;ions network 16 or the
first user's
proxy 18. Telecommunications networks 16 that have the functionality to store
and
execute proxies are generally described herein as "active networks".
In fact, all users outside the system need "generic proxies" representing
legitimate uses of the PSTN, for example, or to represent a PSTN calling
party's
requirements to a connection management proxy, such as caller ID. As an
advanced
feature, users may also be able to specify a special proxy to be used by an
outside
user.
A user with a direct connection to the active network who "roams" into the
PSTN will also want to be able to inform hislher proxy of how helshe can be
found.
This could be done by the user accessing the active network via the PSTN, then
authenticating to the active network, and finally by the user providing an
Internet
domain name to identify the Service Broker with which the User Proxy is
associated
so that the proxy can be located.
This connection management architecture is modular in that each entity is
represented by a separate and independent software proxy which represents its
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interests. If more entities are required to establish a connection, for
example, to add
participants to a conference call, or to use additional signal carriers,
additional
proxies are added to represent each participant. As will be explained
hereinafter, this
modularity simplifies the complexity of the system, which allows advances such
as
openness to new functionality. This modularity also allows for a separation of
concerns, in that each entity need only be concerned about his own
requirements.
Again, this reduces the complexity of the system.
Proxies define a user's policies for creating and receiving calls, which deal
with, for example:
~ incoming calls, deciding which calls may ring a telephone, which should be
returned busy signals and which go to voice-mail;
~ billing, representing the end user's policies on what to pay for, such as
900
calls and disk space for voice-mail and how to pay for those services, such as
requesting a bill or having the costs charged to a credit card account; and
~ outgoing calls, using special "speed-dial" directories or voice-dialling
software.
Generally, any party that may pay bills or charge for services may have a
proxy. The invention is generally described with respect to a model of one
proxy per
owner, but other ownership models could also be used. Proxies can also
represent
groups of users such as local exchange carrier or long distance toll
operators, and
911 dispatch operators.
The strength in the invention's generality becomes clear from the application
to a mixed protocol network as presented in Figure 2. This figure presents a
conference call between three parties 24, 26 and 28, in which two of the
parties 24
and 26 have direct access to the active network 30, and the third party 28 is
connected to the PSTN 32, accessing the active network 30 via an Internet
backbone
34. The two parties 24, 26 with access to the active network 30 are connected
to
personal computers 36, 38 which are located physically close to their
telephones, for
example, in the same house or office. The personal computers 36, 38 are shown
to
be on the active network 30 because they are supporting and executing their
corresponding proxies.
The active network 30 is also shown to include four nodes 40, 42, 44, 46 but
any number may exist, and they may be interconnected in any manner. The proxy
for the active network 30 is shown to reside on node: 42, but could reside on
any of
the four nodes 40, 42, 44, 46. It is desirable to balance the loading of the
nodes by
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spreading proxies around, so proxies may be instantiated with respect for the
loading
on the nodes at the time of instantiation, and may also be relocated if a
particular
node becomes overloaded at any time during a connection. Such multitasking and
load management techniques are known in the art.
The proxies for the Internet backbone 34, PSTN 32 and third user 28, are
shown to reside on r ode 46, but again, they may reside on any of the four
nodes 40,
42, 44, 46 on the active network 30. From the perspective of the invention,
the most
significant point is that proxies have been created foir entities which are
not on the
active network 30, and that would not otherwise have the functionality to
perform the
additional processes. When instantiati,ng proxies, it Is desirable to locate
agents as
close as possible to the corresponding entity, to minimize the time required
for
intercommunication, but this must be balanced in consideration for whether
this
causes too great a load on a single node, compromising its real time
operation: If a
scheduler in a real time node recognizes that it will not be able to execute
in real
time, that is, it becomes overloaded, one or more proxies or their agents may
be off
loaded to another node, such as 40 or 44. Again, such load balancing technique
are
known in the art.
Development and addition of new features to a telecommunication system in the
face of growing complexity to those networks, requires the separation of
concerns
between the entities involved, that the invention provides. It must be
possible to
develop software for a new telecommunications application without being
concerned
about its effect on other applications. The use of a ~>roxy for each entity in
an open
telecommunication system accomplishes this and allows for the addition of new
features by outside parties.
Additional aspects of the invention will be described which provide further
advantages, but in the broad implementation, the use of proxies allows users
to
control the features they have access to. New proxies may be written, edited
or
downloaded from the Internet. Knowledge of the proprietary PSTN switches and
switch software is not necessary, as the proxies may be written in any form of
code.
As noted in the background above, outside parties can not access the PSTN to
add
new features, or modify existing ones.
Also as noted above, new applications on thE: PSTN generally must take into
account all other switch functionality, and legacy hardware and software, so
that they
may be reliably employed. As well, new features ofl:en require upgrades to
software
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and hardware at every switch, and possibly every port that is to offer the
service.
This could require upgrades to thousands of ports over a large area! Because
each
new feature may require such a tremendous investment of time and resources,
PSTN
providers focus on providing commodity products rather than differentiated
products,
and their products take a long time to be brought to market.
In contrast, each proxy need only be capable of providing a certain narrow
functionality, so they may be far less complex. As well, proxies may be
written by
any developer, anywhere in the world. A single developer may write a proxy and
make it available over the Internet, being compensated for ifs use via known
electronic commerce or milli-commerce techniques. !n the preferred embodiment
proxies are assemblies of agents, reducing the complexity of the software even
further.
As a simple example, the invention handles the problem of conflicting
features, such as how to respond to a busy tone: by going to voice mail or
call
waiting? As noted in the background, the existing PSTN must be set up one way
or
the other. In order to switch modes, the user must c:antact the LEC and make a
request for the service change, which may require rr~anual changes to switch
software or hardware, may incur a service charge, and may take a long time to
be
effected. As well, either or both of the services may simply not be available
on the
switch that serves the user. In contrast, with the invention, the user merely
specifies
how the situation is to be handled within his proxy. I-le has complete control
over his
proxy and access to it, so he may change it as often as he requires, simply by
changing a software selection switch on his software interface.
The problems identified in the Background with respect to the Internet are
quite different from those of the PSTN. While the PSTN has centralized
control, the
Internet heretofore has positioned control at the ends of the connection. This
limits
connections to situations where both end users are capable of executing their
own
control, complementary to one another, and all other parties, including the
network
itself, are precluded. Also as noted in the background, Internet software
applications
are generally provided as commodity products as well, and do not have the
modularity to add new features or functionality.
As described above, the invention allows the network or networks to
participate in the connection management process. As well, the modularity of
the
invention allows for easy addition of new features.
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In the preferred embodiment of the invention which is described hereinafter,
additional features are described which provide numerous other advantages. In
general, a Proxy is defined as a state machine having a code structure that
makes for
clarity and allows some sort of intuitive interface. The sequence of actions
involved
in taking a call can be described by a state machine, and the state machine
can be
edited as a graph, one which is in turn responsible for setting up switching
graphs.
Those features and their corresponding advantages are summarized as follows:
Proxies CaII Multiple Agents
Proxies may contain multiple agents, each agent dedicated to a particular
task, and the proxy need only call the agents it needs to perform a certain
task. This provides further modularity, reducing the size of the proxy and
making it easier to understand and modify, and to run faster.
The terms proxy and agent are sometimes used interchangeably in the art.
For the purposes of this document, they are distinct: a proxy is built out of
agents, each of which handles a special situation. Therefore, the proxy does
not comprise an immense block of code with all conceivable functionality, but
in its simplest form, is merely a supervisor which instantiates software
agents
as required, discarding them when their task has been completed.
2. Concurrency
The proxy for a particular entity may be invoked multiple times, to handle
several calls arriving at the same time. This requires that the operating
system be multitasking, which is known in the art, and that the proxy
instantiate multiple agents. As well, multiple Filter Runtime Engines (FREs)
must be instantiated, with one per connection. FREs are the software
environment where filters and agents defined by the graph data packet
execute and are described in greater detail hereinafter.
3. Standard Application Programming Interface (API)
As noted above, an API converts a series of comparatively simple and high
level functions into the lower level instructions necessary to execute those
functions, simplifying use of an operating system.
The particulars of how an API for the invention is implemented are not
critical,
but it is desirable that a standard API be employed that expresses control,
connection and negotiation processes, including payment.
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4. Real Time Operating System (RTOS)
Voice telephony is a real time procedure, so if the system is to be applied to
voice, a RTOS should be used as known in tlhe art. Generally, RTOS's
schedule threads and functions. RTOSs specify deadlines prior to which
blocks of software code must be executed, and use schedulers to ensure that
those blocks of code are executed on time, and in proper coordination with
other blocks of code.
5. Distributed Operating System
A distributed operating system is one in which portions of the software can
run
on different nodes. In the case of a telecomrnunications system, distribution
of software makes it easier to maintain real time operation as there are more
options available to schedule timely execution. As well, distributed operation
improves scalability and speed. The use of agents and proxies lends itself to
the efficient use of a distributed system, in that agents and proxies may be
assigned to run on different nodes of the system. Ideally, agents will be
located close to where they are required, to minimize time delays in
communicating with the entities they represent. Such a suitable distributed
RTOS is described in the co-pending patent application under the Patent
Cooperation Treaty, Serial No. , titled Distributed Telco.
6. One Agent per Node
!t is desirable that a software agent be provided which is associated with
each
node of the system through which the connection passes. Firstly, this
provides a uniform node platform in that all nodes appear to be uniform.
Secondly, this allows for control and configuration of the nodes, for example,
allowing them to raise exceptions if frame error rate is exceeded, latency is
too long, or a similar communication requirement has been violated.
7. Administrative Control
It is preferred that an administrator have access to proxies and authority
over
them, allowing for maintenance and control of the system. This would include
such functions as governing who can create proxies and where they may
execute. Because the invention allows such pervasive functionality over all
manner of telecommunication networks, there is a need for a party which can
offer some measure of control. The Administrator's access would of course
have to be very secure to prevent unauthorized tampering.
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8. Market Model for Agents
It is preferred to encapsulated call processing within a market model. That
is,
having a separate software module corresponding to each of a user's voice,
telephone, ISP, Qwest IP backbone, and other distinct products.
The market aspect refers to ownership of a resource and authority to control
it; therefore, the proxies must identify each resource and the party which
controls it: For example, an Internet Service Provider (ISP) may own
switches and nodes, so his proxy administers those resources; while the user
owns his own telephones so will not accept behaviour that infringes his right.
The ISP will set an information rate which the user has no choice but to
recognize. One can however, modify or delegate authority for one's own
resources.
9. Security Mechanism
A strong security mechanism is required that protects proxies from erroneous
or malicious code in other proxies, as well, pieces of proxies may be
distributed to other users and the proxy owner may not wish for his proxy to
be available to others. These security mechanisms could include digital
signatures such as RSA, or other encryption and authentication techniques
known in the art.
10. Graph Model
It is preferred that the invention be applied to a network which employs a
graph model as described in the co-pending patent application under the
Patent Cooperation Treaty, Serial No. ~, titled "Method and System for
Configuring Communication Resources". Briefly, the graph model describes a
call as a small data structure that simply contains calls to desired filters
and
their locations, rather than containing all the code for the filters
themselves.
The graph data packet may be passed around the network, being reviewed
and amended by various entities. When all or part of the graph into be
executed, a device simply assembles the listed filters in the manner defined
in
the graph data packet.
In addition to filters, it is also preferred that this graph data packet
contain
calls to proxy agents required to set up the call. Two examples of such an
implementation are described herein with respect to Figures 10 and 11.
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11. Graphic User Interface {GUI)
A GUI is piece of software that presents data to users in a graphical manner,
allowing for easy interpretation and modification. It is preferred that the
invention be implemented in such a manner, where possible. The GUI runs
as Java in the PC browser, and communicates with call processing
applications running on the active network by means of sockets. Invoking it
involves typing a UFtL (uniform resource locator such as "coolPhones.com"),
after which it sits in a window waiting for an incoming call or a user input
event
to place a call. Inputs can be made via a mouse, keyboard, trackball,
touchscreen, joystick or other similar manner'.
A GUI is particularly well suited to the use of a graph model as described
above, as the GUl may present the assembled filters as defined by a graph
data packet, to the user in a vary logical and understandable form. It is also
preferred that the GUI have the functionality to let the user modify the graph
data packet simply by altering filters and their interconnections.
12. Persistence
Proxies should persist in the presence of component failures, so that, for
example, a user's forwarding instructions do not get lost during a crash. It
is
preferred that persistence be provided via a distributed database which is
continuously updated, so that all concerned parties are aware of the status of
the communication. In the event of a failure, the system is able to work
around the failure, allowing the communication to continue. Such
transactional interaction techniques are knovvn in the art.
13. JavaT"' Code
It is presently desirable that proxies and agents be written in JavaT"", but
another language with similar advantages could also be used. Advantages of
JavaTM include:
i. excellent security
ii. a large community of experienced developers
iii. object oriented code structure
iv. simple net-based distribution mechanism
1~t. Directories
Directories can be implemented as distributed databases, for scalability, and
custom versions can also exist. A directory really belongs to a user or group
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of users, rather than to the netuvork provider. In an open system, it is
desirable for a private "yellow pages" to prosper; for example, and anyway it
can not be prevented because it could be provided from any IP address,
though less efficiently:
15. Call Manager
A "call manager" wilt be needed for setting up complicated types of calls. For
example, one complication in a three-way calling is what to do when the
originating party hangs up: does the call drop? If not, either the calling
party
may fnd itself handling a number of calls of which it is not part or it will
delegate the task to a call manager. The call manager mechanism can also
be used to simplify the task of calf setup for simple calls.
16. Suitability for Negotiation
It is preferred that the architecture for agents provide for use of the
negotiation
system described in the co-pending Canadian Patent Application No.
, titled "Method and System for Negotiating Telecommunication
Resources".
A telecommunications system implemented vvith the functionality described
above provides a foundation for the mixed media applications of the future,
and for
greater flexibility and power to existing services such as high bandwidth
telephone,
and Internet gaming.
The preferred embodiment is to apply the invention to a wireless access
system as presented in Figure 3. In this figure, the telecommunications
network 16
includes both a public switched telephone network (PSTN} 32 and Internet 48.
Part
of the Internet network 48 is shown to comprise an asynchronous transfer mode
(ATM) network 50, but other telecommunication networks are also compatible
with
the invention including synchronous transfer, integrated services digital
network
(ISDN}, asynchronous digital subscriber line (ADSL), local area networks
(LANs), and
wide area networks (WANs). Users may connect to this network 16 by use of hard
wired telephones 52 or wireless telephones 54 which connect to the network 16
through base stations 56 of service provider BS-A. Note that these base
stations 56
are interconnected via a backbone which may comprise hard wired
interconnections,
IP or ATM routers as shown, or other similar means.
Similarly, computers 58 could access either by wireless, through a base
station 56 as shown, or be hard wired to the network 16. Wireless connections
of
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telephones and computers to the network 9 6 are by means of patchpoints {PP)
60.
Redundant illumination, as shown with respect to computer 58 is preferred
where
possible. Also, telephones may have both wireless and hard wire access as
shown
with respect to location 62.
These arrangements are shown simply as examples, and it would be clear to
one skilled in the art that many alternative arrangemE:nts are also possible.
The software layer of the invention is independent of the hardware layer,
allowing filters, proxies, agents and other software components to be Located
anywhere accessible in the system, dynamically mapped onto appropriate
hardware,
and executed.
In the preferred embodiment, a user proxy is software as described above,
which represents the user's interests on the network. This process is
described in
greater detail with respect to Figures 4 - 7, but as an overview may be
described as
follows:
~ That a user proxy is divided into several parts: a User Proxy object,
multiple
User Reactor objects, and multiple Connection Agents. The User Proxy
object lives on the active network and is responsible for creating and
coordinating the User Reactors and Connection Agents. The User Reactor is
a piece of a proxy that reacts to an incoming event a user has an interest in
and is responsible for handling the instantiation of a connection. The
Connection Agent is responsible for ongoing connections.
~ Methods are provided for User Reactor objects to evolve into Connection
Agent objects when a newly instantiated connection becomes active. A single
User Proxy can have multiple instances of U:>er Reactors and Gonnection
Agents each of which represent the user in a connection. A Connection
Object is an object which corresponds to an active connection on the network
and lives on the Service Broker. It is used to interface the various User
Proxies and starts the negotiation process.
~ A Service Broker is a software abstraction of where a connection and the
connection components interact. Therefore, a Services Broker houses the
User Proxies and any active Connection Objects.
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As weft, the implementation as described herein is based on the following
assumptions:
~ All User Proxies are instantiated at start-up and live on a single server of
the
active network
~ All software components are well behaved
~ All software components are trusted
Figure 4 presents a high level overview of an established connection in an
embodiment of the invention. Each of the two users has an associated Filter
Runtime
Engine (FRE) 64 and a Controlling Application 66 running on its terminal. Such
a
pairing is referred to as an Aware Application 67. Each of the two users also
has an
associated User Proxy 68 which represents its interests and resides on the
active
network. These two User Proxies 68 intercommunicate with one another via the
Connection Object 70.
A Controlling Application's 66 contact with a lJser Proxy 68 is always
established through a User Reactor 72 as shown in (Figure 5. A Controlling
Application 66 is one part of the software which controls a terminal on the
active
network. It sits on top of the Filter Runtime Engine (FRE) 64 and acts as an
interface
between the filters and the User Proxy 68: The Filter Runtime Engine (FRE) 64
is the
software environment where filters and agents defined by the graph data packet
execute. The User Reactor 72 is instantiated when the Controlling Application
66
sends an event to the Service Broker 74 as noted above.
As filters and agents execute on the FRE 64, they may pass events to the
Controlling Application 66, which in turn, passes mei:hods and events back to
the
FRE 64. In other languages methods are called functions, subroutines or
procedures. A JavaT"" method make take any number of parameters or none at
all,
and may or may not produce a result, but may never return more than one
result. All
methods in Java are part of some class, and there are no stand-atone methods,
not
even main.
Events are a more complex Java''"" tool, and may be described as:
~ a way one object can call a method in another, but with a delay. Instead of
doing the work right away, the work is postponed by putting into a queue, so
that the caller can get on with more important work;
~ a flexible way of deciding at run time preciselly which objects should have
their
methods called when something interesting happens; or
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~ a way for letting the callee decide when it wants to be called rather than
leaving that decision totally up to the caller.
Events are transferred between, components using a Channel. There are
several implementations of Channels which allow local and remote transfer of
events.
Each of the components can be considered a layer in the event model and can
pass
an event to either the layer above or bellow itself. The layers, in order of
typical event
transfer, are as follows:
~ FRE fitter events
~ Controlling Application
~ User ProxyIReactorlConnection Agent
~ Connection Object
~ Other participant's Connection Agents
User Reactors 72 are specific to a system and are typically used for two
purposes: configuring a User Proxy 68, and establishing a connection. When the
user wishes to establish a connection the User Reactor 72 sets up the
connection
and then evolves into a Connection Agent 76 which is used for the duration of
the
call. The following is a list of the steps used to establish a connection.
1. Some Controlling Application 66 contacts its User Proxy 68 by opening a
Channel 78 to it. A Channel 78 is a conduit for events used to communicate
between various components in the system. The Channel 78 locates the user
proxy using a unique identifier to identify the Service Broker with which the
User Proxy 68 is associated. In the preferred embodiment a "distinguished
name" is used, in accordance with the LDAP (Lightweight Directory Access
Protocol) standard. The User Proxy 68 creates a User Reactor 72 and
passes it the Channel 78.
2. Next, the Controlling Application sends a message to the User Reactor 72
via
the Channel 78, which identifies the other participants in this connection.
This
identification may be their DN or some other mneumonic such as a telephone
number, which it translates to a DN.
3. The User Reactor 72 then uses the Service E~roker 74 to create a new
Connection Object 70 as shown in Figure 6. The Service Broker 74 uses the
Connection Factory to create the Connection Object 70. A Connection
Factory is the interface on the active network used to create Connection
Objects 70.
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The creation of the Connection Object 70 includes a parameter which is a
reference to the User Proxy fib. The User Reactor 72 then adds the proxy for
the other participant to the Connection Object 70 using their DN.
4. The Connection Object 70 contacts the User Proxy 68 of each of the
connection's participants and requests a Connection Agent 76. A different
method is used for this request if the participant is the caller. This allows
the
User Proxy 68 to evolve the User Reactor 72. into a Connection Agent 76.
The Connection Agent 76 and Connection Object 70 are now able to
exchange events and messages.
5. The Connection Object 70 creates a Floor Olbject 80 as shown in Figure 7,
which takes a list of the participant's Connection Agents 76. A Floor is an
object which handles negotiation, which is preferably implemented as a five
step process:
a. Information gathering: each participant is allowed to declare
information about the connection: This information is stored in name
value pairs. The Floor also fills in certain information about the callers,
like their DN, so they can not falsely represent themselves.
b. Terminal Determination: each participant is asked to determine what
terminal it will use in the connection.
c. Terminal Informing: each participant is informed as to what terminals
the other participants are using.
d. Negotiator Determination: each participant is asked to for a
Negotiation class. This is typically based on what Terminal the
participant is using.
e. Negotiation: the Negotiators 82 are put together into the Discipline 84
(determined in the Connection Factory) which results in PDL (Path
Development Language).
A more detailed description of the negotiation process is available in the co-
pending Canadian Patent Application No. - , titled "Method and
System for Negotiating Telecommunication Resources".
6. The Connection Agents 76 are then responsible for taking the resulting PDL
and sending it to their corresponding Controlling Applications.
As an example, Figures 8A and 8B present a flow chart of a process for
establishing a POTS (plain old telephone system} connection. At step 86,
system
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start up is executed, which includes the start up of a Service Broker 74,
which
instantiates an object for every User Proxy 68 for which it is responsible,
and the start
up of each user terminal.
At step 88, terminal registration begins. The terminal registration process
has
been circumnavigated by a combination of command line parameters to the Aware
Application 67 and information stored in the LDAP (Lightweight Directory
Access
Protocol) database. LDAP is an Internet protocol that email programs use to
look up
contact information from a server. Association with a specific User Proxy is
set by
hard coded information in the User Proxy's constructor and command line
parameters for the application. The initial PDL is read out of a file.
Until the user's telephone or equivalent interiface goes off-hook at step 90,
control will remain in a wait state by looping back to itself. When it does go
off-hook,
control passes to step 92, where a filter reacts by generating an off-hook
event. THe
filter waiting for the off hook could either monitor the; telephone
continuously, or wait
for off-hook until it is instantiated.
This off-hook event may initiate the controlling application at step 94, or it
may
already be installed on the system in which case it changes the state of the
controlling application. Part of this state change may by the return of a dial
tone to
the user's telephone.
The user then begins to enter digits or other keystrokes which are recognized
by a DTMF filter on the FRE as an incoming events at step 96. The DTMF filter
detects these digits and generates digit events which are collected by the
Controlling
Application 66. The FRE sends events by raising an exception of DTMF code + #,
and JavaT"" has a routine to catch exceptions, which acts something like a
software
interrupt.
At step 98, the Controlling Application fib considers whether it has enough
digits to identify the called party, and if not, returns control to step 96.
If sufficient
digits have been received, a Channel 78 is opened to the User Proxy 68 of the
Controlling Application 66 at step 100; which connects it to a User Reactor 72
and
sends a start call message. The start call message includes the digits
dialled.
At step 102, the User Reactor 72 receives the start call message and
translates the digits dialled string into a domain name (DN) for the called
party. The
User Reactor 72 then establishes a connection between the parties as described
above.
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Code Architecture:
The current architecture of the code is separated into three concerns:
~ the core system software, which typically would only be altered by system
administrators or close affiliates. This code includes the Service Broker,
Connection Object, Floor, Channels, and PDL;
~ the Software Development Kit which is a set of base classes and interfaces
for use by developers. This includes abstract classes which define the
concepts of User Proxies, User Reactors, Connection Agents, Negotiators
and Disciplines. There are also some basic implementations of these abstract
classes which make development easier. For example: the LookupCA is an
abstract Connection Agent which has default actions for everything except the
terminal determination. This allows a developer to extend the LookupCA,
implement just the terminal determination method and have a working
Connection Agent; and
~ the remaining pieces of code required to implementation a complete, although
basic, system.
Examples:
Voice-mail and its video and text equivalents are usually thought of as pure
data, but should be seen as objects with methods for reading and writing, or
as filters
that persist after calls complete. The reason to genf:ralize is to allow
different types
of coders including encryption and fax data, to be used in a flexible manner
with
voice-mail.
Therefore reading voice-mail can be thought of as accepting a call, albeit a
time-shifted one. Voice-mails are all pending requests to the called party's
proxy,
and display the graph of the call that set them up, even though it has long
since been
torn down, so that the accepting party can see data type, coding and
encryption
needs, source of call, identify who is paying, and other such information.
A single-use proxy stays alive and attached to the mail, into which one may
also call to retrieve mail. This permits group messaging or retrieval by
password,
situations in which the voice-mail does not know who to contact. In this sense
reading voice-mail can be thought of as originating <a call.
Figure 9 for example, presents a block diagram of a call-processing state
machine responsible far initiating calls according to a conventional dial-tone
model.
In particular, this figure shows the filters that a user assembles to
implement a
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standard dialling model. This representation can be edited graphically, and
different
blocks substituted to allow voice dialling or different interpretations of
numbers, for
example, the PBX convention of dialling 9 to access an outside line or
something
where press-and-hold of a digit gives speed dialling.
A telephone device normally resides in a wait state 106. If an incoming call
arrives, the state shifts to process the incoming call 108. If the telephone
goes off
hook, processing shifts to the dialling interpretation routine 110 which
offers a dial
tone to the user until the first keystroke is made, which causes a
corresponding
DTMF signal to be returned, and a change made to state 112. Processing then
awaits the entry of additional keystrokes which are interpreted in state 114
and
corresponding DTMF signals are returned. Once the dialled number is complete,
control passes to the call set up routine at state 116. Call setup is executed
as
described above: set up your half of the call per steps 106 - 114, then a cal/
manager
will make the connection to the called party or parties. The called party or
parties
may return withe counterproposals as part of the negotiation process, and the
call
manager adjusts the cafi graph as required, or allowed by the calling party's
proxy.
The user may have changes to he call graph flagged to him, or allow them to be
accepted without review
Figure 10 presents a block diagram of a calf-processing state machine with
detailed billing in an embodiment of the invention. Filters for billing
services are
simply interposed between the body of the call 118 .and the ultimate source of
money,
represented in this case by a credit card company 120. The call manager passes
the
billing service 122 a copy of the entire call graph on call setup so that it
has all the
necessary information to describe the call, and it also receives copies of
warranty-failure alerts from the warranty monitoring filter 124. It stores its
results on
rented disk, which can then be read through a Web interface or printed and
mailed.
The call graph presented in this figure is bet~Neen the source 126 and
destination 1 128, and has been negotiated through a channel 130 which has
guaranteed a certain minimum latency. As part of the call graph, the source
126 has
therefore inserted a latency cop 132 which monitors the latency through the
channel
130 and advises the warranty filter 124 if the channel 130 has failed to meet
its
obligations by sending it failure signals. The duration of the call is also
sent by the
timestamp 134 through the graph for use by the billing service 122.
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if there is a failure, the warranty filter 124 will affect some form of
compensation to the source 126 andlor destination 1128, which may, for
example,
be in the form of free transmission frames. This information is passed on to
the
billing service 122 which compiles the bill, forwardinc,~ it to the credit
card filter 120,
which confirms the payment back through the other filters in the chain.
Similarly, Figure 11 presents a block diagrann of a call-processing state
machine with multiple independent bills. Multiple billing sources are handled
by
attaching different money sources to different subgraphs. In this example, a
broadcast-type transmission is being made from a source 136; through a
splitter 138
to two receivers: destination 1 140 and destination 2 142. Each of the three
parties
has an independent credit card filter 144, 146 and 148, to settle the
respective costs
to each of the three parties. This model is useful in the case of point-to-
multipoint
services, like MBone or other pseudo-broadcasts.
Examples have been shown to demonstrate various aspects of the invention,
but the number of variations is by no means complete. Comparable
implementations
could be made for any telephony device, including personal digital assistants,
fax
machines, pagers, point of sale computers, amateur radios, local area networks
or
private branch exchanges. While particular embodirnents of the present
invention
have been shown and described, it is clear that charges and modifications may
be
made to such embodiments without departing from the true scope and spirit of
the
invention.
The method steps of the invention may be embodied in sets of executable
machine code stared in a variety of formats such as object code or source
code.
Such code is described generically herein as programming code, or a computer
program for simplification. Clearly, the executable machine code may be
integrated
with the code of other programs, implemented as subroutines, by external
program
calls or by other techniques as known in the art.
The embodiments of the invention may be executed by a computer processor
or similar device programmed in the manner of method steps, or may be executed
by
an electronic system which is provided with means for executing these steps.
Similarly, an electronic memory means such computer diskettes, CD-Roms, Random
Access Memory (RAM), Read Only Memory (ROM) or similar computer software
storage media known in the art, may be programmed to execute such method
steps.
CA 02347405 2001-03-26
WO 00/19677 PCT/CA99100876
-29-
As well, electronic signals representing these method steps may also be
transmitted
via a communication network.
It would also be clear to one skilled in the art that this invention need not
be
limited to the described scope of computers and computer systems. The
principles of
the invention could be applied to citizen's band radio, amateur radio, or
packet radio.
Again, such implementations would be clear to one skilled in the art, and do
not take
away from the invention.
