GB2271910A - Digital access signalling architecture - Google Patents

Abstract

A digital access signalling architecture based on three independent components, namely application management 22 human machine interface (HMI) management 21 and connection management 20. Call control 24 is provided by either HMI management or application management. Connection control 23 is provided by connection management. The clear separation of these independent components provides a very flexible signalling architecture whilst not in any way restricting the ability to control basic and supplementary services, and at the same time providing a framework within which existing signalling systems can converge. The architecture also enables users to move effortlessly between multiple simultaneous applications. <IMAGE>

Description

DIGITAL ACCESS SIGNALLING This invention relates to digital access signalling systems and in particular to their evolution in order to be able to provide an enhanced platform for the development of future telecommunications services.

"Lift handset, dial tone, *55*0730#, indication, replace handset". Ten years ago, this was the CEPT's recommended access signalling sequence to activate a 7.30am alarm call - one of the many new services that were made possible by the development of Multi Frequency (MF) access signalling systems.

Today, in the early 90s, a much greater range of services can be provided through the increasing use of powerful message-based signalling systems in association with ISDN and Digital Cellular Networks. Access signalling systems represent a key factor in a network's ability to offer new services and consequentially in the ability of Network Operators and Service Providers to open up new revenue streams.

According to the present invention there is provided a digital access signalling system involving three independent components, which components comprise an application management component, a human machine interface (H MI) management component and a connection management component.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which: Fig. 1 illustrates the provision of telecommunications services by a range of applications running in a variety of locations; Fig. 2 illustrates ISDN and computer-to-switch application interfaces enabling the interchange of information and control with user applications; Fig. 3 illustrates the signalling architecture according to the present invention; Fig. 4 illustrates establishment of an HMI association and voice connection to a conference application in order to facilitate management of a conference call; Fig. 5 illustrates transfer of access to the user's display and soft keys to the voice mail application whilst the voice connection is still to the conference bridge;; Fig. 6 illustrates the voice mail application requesting the exchange application to reconfigure the connection when the user requests to read the voice mail; Fig. 7 illustrates use of a wireless notebook computer to manage remotely exchange, video and file server applications; Fig. 8 illustrates dedication of HMI resources to specific applications eg. key and lamp pairs, in order to support multiple simultaneous applications, and Fig. 9 illustrates the architecture of the present invention providing a framework for the convergence of existing digital access signalling systems.

In today's competitive environment, flexibility is the key to survivaL Network Operators and Service Providers need the ability to display new services rapidly in the marketplace, both to meet the changing requirements of their customers and to differentiate themselves from their competitors. To facilitate rapid deployment, access signalling systems must provide mechanisms for the management of services that are truly transparent to the services being offered. Without service transparency it would be necessary to enhance both the access signalling system and the user's terminal before a new or modified service could be introduced.

Advanced Intelligent Network (AIN) achitectures rely on the introduction of service independent platforms in order to facilitate the rapid creation and deployment of new services.

Access signalling systems, and indeed terminals, are an integral part of that platform. Service transparency is a very effective way to ensure that access signalling systems do not become a limiting factor in the overall service velocity of the network (speed of deployment of new services).

Service transparency is, therefore, one of the essential characteristics required in access signalling systems.

In the past, access signalling systems have focused on the need for the user to manage the services provided by their local exchange. This situation is changing rapidly. Services can now be offered to the user from applications running in a wide variety of locations both within and outside the network. An example of this is illustrated in Fig. 1. Inside the public network 1, services provided by the local exchange (local exchange applications 2) are complemented by services realised in Service Control Points (SCP) (Centralised SCP Applications 3) or remote exchanges (remote exchange applications 4). Outside the network, services are also provided from value added applications 5, and from the user's terminal itself (terminal based applications 6). However, many of these applications have one thing in common.They are all competing for the user's attention, and therefore access to the user's Human Machine Interface (H MI). The challenge of the future will be allowing the same user to move effortlessly between multiple simultaneous applications.

Thus effective management of multiple simultaneous applications is therefore another important new characteristic which will be required in future access signalling systems.

As business competition increased and decision intervals shorten, business people are finding it important to stay constantly in touch. Sales personnel are being encouraged to spend less time in the office and more time talking and listening to their customers and prospective customers. As outsourcing increases, a wide range of professionals find themselves increasingly on the move, visiting and working with their clients. The logical conclusion of these trends is the emergence of a group of Truly Mobile workers, who need to recreate as many aspects as possible of their office environment, while they are on the move. Therefore in providing services to such workers, applications must be capable of adapting to a range of terminals and their associated HMIs.

Access signalling systems must therefore allow users to access services from a wide range of terminal types.

The introduction of powerful message based signalling systems has greatly increased the potential for exchanging information and control between the network and user applications. For example, an ISDN interface 10 enables call forwarding information to be delivered to an automated voice answering system 11 so that the application can interact with the forwarded user appropriately. Automatic Call Distribution (ACD) services 13 use computer-to-switch application interfaces 12 to interact with telemarketing applications 14, enabling call delivery simultaneously with the automatic retrieval and display of clients records. This is illustrated in Fig. 2.

As will be appreciated, Figs 1 and 2 are just two examples of the improved levels of service and productivity that can be achieved through the exchange of information and control between the network and user applications. Enabling such intelligent interactions therefore represents an important and growing revenue stream for Network Operators and Service Providers.

Communication is inherently multi-media. Existing networks have, however, traditionally focused on single media services. It is therefore not surprising that existing access signalling systems are oriented towards the control of single media services.

However, the introduction of narrow band ISDN and the trialling of broadband networks have made multi-media communications a reality.

In a multi-media environment, a communication between two users may start as a voice service, expand to incorporate a video service, and finish as a data transfer service. Thus a single call could involve the management of three different types of connections. As a consequence, it is necessary to separate out more clearly two different aspects of access signalling, namely call control and connection control. Call control enables the user to manage a range of basic and supplementary services, whereas connection control establishes and releases the information transfer carrying capabilities associated with the service requested by the user.

Separation of call and connection control is therefore a further key characteristic required in future access signalling systems, as it enables multi-media services to be controlled more effectively.

To provide an enhanced platform for the delivery of new services, it is therefore essential that future access signalling systems exhibit all of the key characteristics identified above: - the ability to control services transparently to the services themselves; - the ability to manage multiple simultaneous applications effectively; - the ability for users to access services from a wide range of terminals; - the ability to support the interchange of information and control with value-added user applications; - the ability to control multi-media services through the separation of call control and connection controL Many of today's signalling systems provide different subsets of these characteristics, rigidly packaged in specific combinations.

What is missing is an architecture which allows the different aspects of access signalling to be combined in a flexible manner.

Historically, digital access signalling systems have been structured around the commercial needs to control basic and supplementary services. In contrast, this invention proposes that future access signalling systems be structured around the following three independent components of access signalling, namely: - Human Machine Interface (HMI) Management; - Application Management, and - Connection Management The clear separation of these independent components provides a very flexible signalling architecture, whilst not in any way restricting the ability to control basic and supplementary services.

Connection Management 20 is the simplest component of the architecture and provides for establishment, switch through, and release of information channels on the access. Collectively, these capabilities can be thought of as Connection Control 23.

HMI and Application Management 21 and 22 complete the architecture by providing two complementary alternatives for Call Control 24. This is illustrated in Fig. 3.

HMI Management provides a service - transparent mechanism for signalling between multiple applications and a terminal's HMI. It supports the rapid deployment of new or modified services in a manner which allows the HMI resources of different terminal types to be fully exploited. To provide terminal independence, each terminals HMI is mapped onto an upward compatible series of virtual terminals classes ranging from simple telephone sets, through feature phones with displays and soft keys, to Graphical Use Interfaces and beyond. However, as a result of its service transparent nature, HMI Management cannot be used to interact effectively with user applications in an intelligent manner.

This role is played by Application Management, whose procedures enable the exchange of information and control with user applications located on either centralised computers or individual terminals. This integration of computing with telecommunications provides a very powerful platform for the enhancement of a wide variety of applications, including telemarketing and customer service bureaus. However, as a result of its service-specific interactions with the network, Application Management signalling will typically require user applications to be updated to exploit any new network capabilities, unlike HMI Management. This makes Application Management an inappropriate vehicle for the rapid deployment of new and modified services.

The roles of HMI and Application Management are, therefore, complementary. In addition, their clear separation, combined with a common solution for Connection Management, provides a very powerful architecture. Such an approach avoids the introduction of unnecessary compromises and rigidity into the signalling system, and allows the exact functionality required to be selected in a flexible manner from a single solution.

The potential of this architecture is best illustrated by considering examples of how it can be used to provide an enhanced platform for the delivery of new services.

Consider the arrangement illustrated in Fig. 4. A Marketing Director in the UK is speaking over a voice conference bridge with the Product and Design Directors in North America. The conference application 41 is assumed to be located in N America so that only a single transatlantic connection is required.

However, an HMI Management association is established between the Marketing Directors feature phone 42 and the remote conference application 41. This enables the conference application 41 to have access to the feature phones display and softkeys to provide a more intuitive service interface to the Marketing Director.

During the conference call, a question arises on the situation in France. The market prime in France had promised to leave a voice message the previous evening - it should be on the voice mail system. The message waiting indication on the phone 42 is on, so that there is at least one message waiting. However, with the new architecture there is no need to put the existing conference on hold; instead a second HMI Management association (Fig. 5) is established with the voice mail application 43. Access to the display and soft keys is now passed to the voice mail application, and the Marketing Director can scan his voice mail while still listening to the conference call.

The marketing director locates the message from the French market prime. Rather than worrying about how to hold the connection to the conference and establish a new connection to the voice mail system, the Marketing Director simply presses the nRead" key. That command is passed to the voice mail application 43, which uses an Application Management dialogue with the local exchange 44, to complete the necessary commands on his behalf (Fig. 6).

The flexible use of HMI, Application and Connection Management procedures have therefore made it possible for the Marketing Director to manage this complex telecommunication environment in an intuitive and user-friendly manner.

In a second example, consider an Engineer visiting a subcontractor's office in order to discuss the development of a new car. At the Engineer's office a video file server 71 (Fig. 7) holds a number of videos of the concept model of the car and a file server 72 holds the CAD (Computer Aided Design) information.

During the discussions, the engineer decides it would be useful to show a number of the concept videos on the subcontractorts HDTV (High Definition Television) facility 73. Using a notebook computer 74 with digital cellular access, the Engineer establishes an HMI Management association with the exchange application 75. Once security procedures are complete, the Engineer uses the association to establish an appropriate connection between the video file server 71 and the subcontractor's HDTV facility 73. Then by establishing a second HMI Management association with the video application 76 itself, the Engineer is able to control the selection and presentation of the videos themselves.

While one of the videos is playing, the Engineer accesses the exchange application 75 a second time, in order to set up an additional connection between the file server 72 and the subcontractor's file server 77. Then by establishing a third HMI Management association with the file server application 78 itself, the Engineer is able to select and institute transfer of the appropriate CAD files. It is important to note that the separation of HMI Management from Connection management has allowed the signalling path to follow a separate route from the paths of the connection. In addition, the reuse of HMI Management associations to control the video and server applications provides a consistent, efficient and standardised approach for managing the complete environment.

As will be apparent from the above, the architecture provides a structured approach to digital access signalling. The HMI Management is used to provide service transparency. As with existing signalling systems, service transparency is achieved by enabling applications to interact directly with a user through a logical representation of the terminals HMI. However, unlike existing signalling systems, the logical representation of the terminal is organised as a series of upward compatible classes, which enables the application to interact with the user at the highest level available to both terminal and application. The basic class could be for POTS sets with HMI resources such as keypads and a variety of ringing cadences and dialling tones.

Higher classes could be used for feature phones with HMI capabilities such as displays, soft keys and keys and lamps.

Higher classes still could be used to represent Personal Computer based terminals with HMI capabilities based on Graphical User Interface (GUls).

HMI Management also enables the simultaneous support of multiple applications by allowing the HMI resources of the terminal to be used flexibly in either a dedicated or a shared role. Dedicated HMI resources are assigned to specific applications in order to guarantee a minimum level of interaction between the application and the user. The dedicated resources could take the form of key and lamp pairs 81 (Fig. 8), a softkey in a menu, or an icon in a GUI. In the example described with reference to Figs 4, 5 and 6, a key and lamp pair was assigned to the voice mail application so that the application could signal that messages were waiting and that the user could activate a session with the voice mail application. Shared HMI resources are available to any number of applications on a temporary basis under the control of the user.In the example described with reference to Fig. 4, 5 and 6, the display and softkeys were a shared HMI resource between the conference and voice mail applications.

Application Management provides a complementary alternative to HMI Management for Call Control which enables a user application to interact intelligently with the network. The HMI Management exploits service transparency to provide a very flexible solution for rapid service deployment. However, as a result of its service transparent nature it is not possible for a terminal to track the state of the service or to interpret any of the information it receives. Application Management, on the other hand, supports exchange of service specific information and control with the network and thereby enables the user application to add value.

HMI and Application Management therefore provide complementary alternatives for Call Control with Connection Management providing a common set of procedures for Connection Control. A service such as a speech bearer service call could therefore be invoked through either the HMI or Application Management, but it would be the same Connection Management procedures that would be used to establish, switch through and release the associated information channel on the access.

Many business users are currently connected to Centrex and PBX services via feature phones. These are typically interfaced to the switch via proprietary digital interfaces which support a wide range of voice and data services. This type of interface could be described as a mixture of HMI and connection control functionality. With the architecture of the present invention, feature phones would be served by a combination of HMI and Connection Management. This solution provides an enhanced platform for the delivery of business services with the following advantages over many existing feature phone signalling systems: - access to multiple simultaneous application, and - support of an upward compatible range of HMI classes.

ISDN user terminals are supported by DOSS1 (Digital Subscriber Signallinvsystem number 1) which is defined by CCITT recommendations Q.930 to Q.931. DOSS1 is primarily a functional signalling protocol which allows the ISDN terminal or PBX to add value through the interchange of information and control with the network. These capabilities correspond to a mixture of Application and Connection control functionality. In addition, a limited number of service transparent procedures are provided for the control of supplementary services. These correspond to a subset of the HMI Management signalling procedures of the present invention. Under the architecture of the present invention, ISDN functionality would be supported through a combination of HMI, Application and Connection Management.

The inventive solution offers the following advantages over the DSS1 standards.

- a more powerful platform for service transparent signalling; - improved control of multi-media services through a cleaner separation of call and connection control, and - a common approach for application control functionality with SCAI (Switch Computer Application Interface) Computer-to-switch application interfaces are the subject of study in both ECMA and ANSI accredited T1 committees. The access signalling procedures used on these interfaces enable value added user applications to interact intelligently with the network. As the computer-to-switch application interfaces are logically associated with the informal channels they support, they do not require connection control functionality. For example, a computer-to-switch application interface used to link a switch with a telemarketing application will be logically associated with the ACD lines that support the agents.

Therefore, there is no need for connection control on the computer-to-switch application interface. This is different from ISDN in that the physical association of the signalling channel with the information channels i.e. a Basic or Primary rate configuration, has created a mixture of connection and application control functionality in the signalling system.

Under the architecture of the present invention, the computer-to-switch application control functionality would be released by the Application Management. This solution offers the following advantages over currently proposed computer-to-switch applications signalling standards: - a consistent solution for both physically and logically associated information channels, and - HMI Management procedures which allow an application access to the HMI of the users' terminals.

Therefore, one key benefit of the architecture of the present invention is that it provides a framework within which the existing access signalling systems can converge - avoiding unnecessary duplication of functionality and a proliferation of differing solutions. For example, it can provide a common approach to Application Management between ISDN and computer-to-switch application interfaces 91 and 92, and a common approach to Connection Management between ISDN and feature phones 91 and 93. See Fig. 9. Convergence onto a single access signalling architecture avoids added development costs for the manufacturer, increased complexity for the operator and ultimately a more expensive and less flexible solution for the end user.

Claims (8)

1. A digital access signalling system involving three independent components, which components comprise an application management component, a human machine interface (HMI) management component and a connection management component.

2. A system as claimed in claim 1 wherein the connection management component provides connection control, and wherein call control is provided by either the HMI management component or the application management component.

3. A system as claimed in claim 2 wherein call control enables a user to manage a range of basic and supplementary services, and wherein connection control establishes information transfer carrying capabilities associated with a said service requested by said user.

4. A system as claimed in claim 1 or claim 2 wherein the connection management component provides for the reservation, switch-through and release of information channels.

5. A system as claimed in claim 1 or claim 2 wherein the HMI management component provides a services transparent mechanism for signalling between multiple applications and the HMI of a terminal.

6. A system as claimed in claim 5 wherein the HMI of a terminal can be mapped onto any one of a series of virtual terminal classes of increasing complexity.

7. A system as claimed in claim 1 or claim 2 wherein the application management component provides exchange of information and control with user applications located on computers or terminals.

8. A digital access signalling system substantially as herein described with reference to and as illustrated in Fig. 3 or Fig. 9 of the accompanying drawings.