Abstract:
A home WAP gateway system is disclosed that provides user selectable access from digital cordless telephone handsets adapted to WAP communications to services of a local home WAP gateway or to services of a remote WAP gateway in a public network. By a switching means responsive to a message from a handset comprising switching information, the system provides a communication path between a communicating handset and a home WAP gateway when the switching information specifies a predefined home WAP gateway path or between a communicating handset and a public or private telephone network when the switching information specifies a different path.

Description:
FIELD OF THE INVENTION 
     The invention relates to the field of wireless data communication, and particularly a system based on digital wireless telephone systems technology such as the standardised Digital Enhanced Cordless Telecommunication (DECT) and operating according to the Wireless Application Protocol (WAP) for providing access to local data applications and data files on a private “home” WAP gateway. 
     Without getting as much attention as cellular phones, cordless telephones (CT) are becoming widespread consumer products, and they are paving the way towards ubiquitous low cost personal communications networks. The cordless telephone systems were first manufactured and made commercially available in 1980s. They operate solely as an extension telephones to a transceiver connected to a subscriber line on the public telephone network (PTN) and are primarily for in-home use. They enhance fixed telephones by offering more freedom and higher mobility degree, i.e. allowing the user to operate in a wider area. Cordless telephone systems are generally full duplex communication systems that use radio to connect a portable handset to a dedicated base station, which is then connected to a telephone line associated with a specific telephone number on the public telephone network (PTN). In the first generation, the portable unit communicates only to the dedicated base unit and only over distances of a few tens of meters. Cordless telephone systems provide the user with limited range and mobility, as it is usually not possible to maintain a call if the user travels outside the range of the base station. Typical second generation base stations provide coverage ranges up to a few hundred meters. FIG. 1 illustrates a typical state-of-the-art cordless telephone system. 
     CT2 is a digital version of the first generation, analogue cordless telephones, introduced in Great Britain. When compared with analogue cordless phones, CT2 offers good speed quality, is more resistant to interference, noise, and fading, and like other personal telephones, uses a compact handset with built-in antenna. The Digital European Cordless Telephone (DECT), later renamed to Digital Enhanced Cordless Telecommunication, is a universal cordless telephone Standard developed by the European Telecommunications Standards Institute (ETSI), issued in 1992. 
     The Problem Areas 
     Although digital cordless telephone standards such as DECT specify both voice and data applications, they are limited to the bearer level, that is the ISO-OSI physical and data link layers (layers  1  and  2 ) and are not sufficient to enable data applications on the handset (or portable unit). 
     Known Solutions and Problems with These 
     Generally, existing cordless telephone systems on the market allow only voice communication services on the handsets. Such a limitation is expected soon to be intolerable by the market now that the WAP enabled cellular phones are being launched. The need for a solution enabling access to data and applications both on the world wide web and locally on a PC or workstation via cordless telephone is getting more and more urgent. With the advent of the Internet and the arrival of new generation of handsets having larger displays, the demand for data applications for cordless telephone systems is imminent. 
     There are some activities in the “WAP Forum” aiming to define DECT as an access technology enabling WAP, and to specify how to implement it. A description in this regard is given in the document “CR to WAP” of May 29, 1999, Change Request to WAP Forum Ltd, San Francisco, by Arjan te Marvelde, Ericsson, and Dr. G. Kelnhofer, Siemens. However, these activities have focus on the protocol level, i.e. how should the protocol stacks be for different units (handset, Fixed part, WAP gateway, etc.). The main architecture for WAP over DECT is the standard WAP architecture where the public WAP gateway is own and administered by a network operator or a service provider. Such a WAP gateway will also serve a number of users having subscription to the network operator or service provider. As shown in FIG. 2, in the “WAP over DECT” architecture the user via his DECT handset can have access to a WEB/WAP server via a public WAP gateway. Such a solution will allow the DECT users to access data and applications residing on remote computers or servers which are in the World Wide Web. However, the architecture does not give direct local access to data and applications residing on a local PC or workstation. 
     At present the applicant is not aware of any solution that enables access to both data and applications on the web and those residing on a local PC or workstation via cordless telephone handsets. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention to extend the “WAP over DECT” architecture and thereby allow access from cordless telephone handsets to data and applications on the web as well as those residing on a local PC or workstation. 
     It is a further object of the present invention to propose a way to obviate the limitation in current cordless telephone systems and to enable all data application types, ranging from Web content access to management of the cordless telephone system itself by means of the Wireless Application Protocol (WAP). 
     BRIEF DISCLOSURE OF THE INVENTION 
     In order to enable data applications on digital cordless telephone systems which can be CT2, DECT or others, this invention promotes the introduction of the Wireless Application Protocol (WAP) in a single base station cordless telephone system. The invention proposes a new architecture for home WAP where a PC-based private WAP gateway is introduced. The private WAP gateway may be owned and administered by the user or user organisation as in the case of a small office or a private home. Such a private WAP gateway allows the user to have access to data applications located locally in his PC as well as those residing on a WEB/WAP server on the Internet. 
     The objects of the invention are met by a system comprising at least one local PC or similar computer device serving as a local WAP gateway, at least one DECT bases station, and one or more DECT handsets adapted to wireless communication with said at least one base station, wherein the DECT base station is connected to the local WAP server and optionally to a public communications network, the system further comprising a switching function for routing information traffic between the DECT handset and the selected WAP gateway. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic drawing illustrating a typical state-of-the-art cordless telephone system, 
     FIG. 2 is a schematic drawing illustrating a PRIOR ART proposed “WAP-over-DECT” architecture, 
     FIG. 3 is a schematic drawing of an example of a WAP cordless telephone system according to the invention, 
     FIG. 4 is a schematic drawing illustrating an example of components in the WAP cordless telephone system shown in FIG. 3, and 
     FIG. 5 is a schematic drawing of another example of a WAP cordless telephone system according to the invention 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In the following, the present invention will be described by way of examples and with reference to the accompanying drawings. 
     As shown in the example of FIG. 3, the architecture of a first example of the “Home WAP cordless system” according to the invention could include the following main units: 
     a home WAP gateway based on a personal computer (PC) or similar computer device, 
     a Base station (also called Fixed Part in DECT terminology), and 
     one to twelve handsets. 
     The PC is connected to a DECT cordless base station by a standard means for data communication such as USB (Universal Serial Bus), RS232 serial connection or other standard peripheral bus. The PC will provide the WAP gateway function. The WAP gateway function could include standard gateway functions, such as: 
     a WAP protocol stack, a bearer adaptation for the cordless standard (DECT), 
     a management unit, 
     a context manager to correlate the device-to-gateway and gateway-to-server sessions, 
     a compiler and encoder to convert WML to binary code, and 
     an HTTP manager to manage the session between the gateway and the WEB/WAP application servers. 
     The connection of the PC to the Internet can be achieved in several ways. It can be done via for example TV cable or xDSL. The network connection can also be accomplished via a regular PSTN/ISDN data call. The connection for the data call may be established via the cordless base station or directly to a PSTN/ISDN network. The PC may also contain control and management software for the base station, and software for providing voice-based services like PBX and answering machine functions. 
     In the example of FIG. 3, the base station, which may also be referred to as the fixed part of the cordless system, in addition to the basic functions of a regular cordless base station, provides the switching function that permits to direct WAP data requests from the cordless handset to either the home WAP gateway function of the local PC or the public WAP gateway. It is contemplated that the switching function could be pre-configured via an interface on the base station, or it can be set upon request from the user via a cordless handset. The WAP data request is based on standard data communication capabilities provided by the cordless communication system. 
     FIG. 4 shows components of a WAP cordless telephone system shown in FIG. 3, including the protocol stacks of the handset, of the base station and of the Home WAP gateway in the case where the home WAP gateway is used. It is important to note that the cordless radio does not indicate any specific radio protocol but general protocol layers  1  and  2  in the ISO OSI layers which are necessary to realise the radio link between the base station and the cordless handset. The case where the public WAP is used is not part of invention and has been described by the referenced prior art. The cordless handset is equipped with a WAP protocol stack and a micro browser that is capable of handling the Wireless Mark-up Language (WML) and the WAP Application Environment (WAE). From the micro browser the user can choose to use either his “Home WAP gateway” or public WAP gateway: 
     To use his Home WAP gateway the user could specify: 
     home: &lt;URI&gt; 
     where &lt;URI&gt; is a standard World Wide Web Universal Resource Identifier. 
     For accessing a local file on the PC, the URI could be for example be specified as: 
     file://myfilename 
     For an object or resource on the “web”, the URI could be for example be specified as: 
     http://www.ericsson.com/ 
     Upon receipt of the keyword home, the switching function in the base station will forward the data request to the Home WAP gateway in the PC via a local connection such as a serial or USB connection. The Home WAP gateway will carry a protocol conversion and assembling, and then forward the data request to the appropriate final destination. 
     To use a public WAP gateway the user may specify: 
     public: &lt;URI&gt; 
     where &lt;URI&gt; is a standard World Wide Web Universal Resource Identifier. It is worth noting that in this case the user can no longer access the local files on his PC. 
     Upon receipt of the keyword public, the switching function in the base station will forward the data request to public gateway that the user has subscription with. Depending on the network connection type and protocols, i.e. circuit switched or packet switched the base station will carry the appropriate actions to establish the connection with the public gateway in order to deliver the request. 
     In FIG. 5 is shown another example of a “Home WAP cordless system” according to the invention. The system could include the following main units: 
     a home WAP gateway based on a personal computer (PC) or similar computer device, 
     a DECT cordless telephone base station (also called Fixed Part in DECT terminology) unit, 
     a telephone line switching unit (could be an integral part of the home WAP gateway computer), and 
     one to twelve handsets. 
     By assigning to the home WAP gateway one or more special telephone numbers that have characteristics which are significantly different from the numbers typically used by public telephone networks, the switching unit will be able to distinguish between calls made to the public telephone network such as PSTN or ISDN and calls made to the home WAP gateway. A call made to the home WAP gateway would be intercepted by the switching unit, and a connection would then be established between the home WAP gateway and the base station. Subsequently the user would access the home WAP gateway in the same way as any other WAP gateway. 
     A combination of digits that could be suitable for many telephone systems for assignment as a number for a home WAP gateway connection could for example be four or more consecutive zeros. In such a case, to connect with the home WAP gateway the user could specify a number such as: 
     0000. 
     For each call, combinations of digits which are different from the number or numbers assigned to the home WAP gateway will be disregarded by the switching unit in the sense that they will be routed through to the telephone line connection, as will any communications traffic associated with such calls. 
     Accordingly, to connect with a remote WAP gateway of a service provider on the public network, or for the sake of placing an ordinary telephone call, the user would specify a typical telephone number such as: 
     81007107. 
     It should be understood that the switching unit, shown in FIG. 5 as being connected to the telephone line interfaces of the cordless phone base station and the telephone network and to a communications interface of the home WAP gateway, could be an integral part of the home WAP gateway itself. 
     Uploading of software for and configuration of the switching means could be made from either the home WAP gateway, from the digital cordless telephone handset, from a device connected to the telephone network or via a dedicated interface of the switching means, or from a combination of any of the aforementioned. 
     Advantages 
     The present invention has multiple merits: 
     It extends the range of applications for the cordless phone user from voice to data applications. 
     It is probably the best way to enable data applications on cordless telephone system by using the Wireless Application Protocol. This is due to several reasons. Firstly, WAP is intended for mobile devices with small display, limited keypad, no pointing device, and limited processing power and memory capability similar to the capabilities of a DECT handset. The multi-bearer architecture of WAP makes it simple to adapt to DECT. Secondly, WAP does not, for the time being, have any serious competitor within the phone segment, and it has been accepted by a wide range of telecom manufacturer and operators and is on its way to become a de-facto standard. Thirdly, seen from a user&#39;s point of view it is much better to have the same interface on the DECT handset as on the cellular phone. 
     In particular, a system according to the invention may provide a highly competitive low-end alternative to screenphones and similar low-end web services in order to provide simple data applications on home or small office phones.