WO2002082841A1

WO2002082841A1 - Data transmission system in which a mobile terminal is used as a virtual workstation.

Info

Publication number: WO2002082841A1
Application number: PCT/FI2002/000230
Authority: WO
Inventors: Jari Peuralahti; Kari Rajahalme
Original assignee: Oy Datatie Ab
Priority date: 2001-03-22
Filing date: 2002-03-20
Publication date: 2002-10-17
Also published as: FI118916B; FI20010590A; FI20010590A0

Abstract

A data transmission system for sending information over PLMN network (3) via wireless interface (2) linked with PLMN between terminal (1) and resource server (8), which PLMN network (3) is in data transmission communication via resource server with data network (5, 6, 7) such as LAN network. According to the invention, in order to change PLMN terminal into virtual workstation of resource server (8) in communication with PLMN network, resource server of data transmission system is located in data transmission path from terminal over PLMN to resource server after PLMN switching centre (33). The data transmission capacity of interface between terminal and PLMN base station (31) is at least 20kbps, and the resource server remote control and use facilities include communication protocol between terminal and resource server, with the means of which only mouse clicks etc. transfer from terminal over PLMN to resource server in which applications runs, and only changed display data transfers from resource server over PLMN to terminal.

Description

Data transmission system in which a mobile terminal is used as a vir.tual workstation .

5 The present invention relates to telecommunications and data transmission. In more detail, the object of the present invention is a transmission system for transmitting information or data over a mobile communication or a cellular radio network, that is, a public land mobile network, into another PLMN network with the means of a wireless interface between connecting terminal, such as a mobile station or a pocket 10 computer or a portable computer, and resource server, which public land mobile network is advantageously in telecommunications and/or data transmission communication with a packet switched data network, such as LAN, WAN, intranet, X.25 network, IP network etc.

15 In general, it can be stated on PLMN communication that wireless communication enables the production of many customised services for PLMN system users. Such wireless mobile services include special features which give added value for users. Such added value comprise, for example, of: mobility or possibility to maintain continuous speech and/or data 20 communication even though the user is on the move, quickness or possibility to switch into the PLMN system network irrespective of place without long waiting periods, and regionalisation or possibility to gain relevant information on present location.

By combining these added value features, one is able to create different service 25 entities, examples of which are: communication: electronic mail, fax, uniformed communication, intranet or Internet connection;

VAS or value added services: information, games; electronic commerce: retail, ticket sales, banking, stock exchange; location-dependent applications: navigation, traffic monitoring, timetables, localisation; vertical services, freight services, delivery area management, direct sales; and advertising.

In this patent application, PLMN system generally means any such mobile phone or cellular radio system in which digital information is transmitted over the radio interface between terminals and base station pertaining to PLMN system with the means of a wireless interface which applies xDM multiplexing, that is, advantageously CDM, TDM and/or FDM multiplexing.

In this application, telecommunications network means any such commercial or noncommercial, usually circuit switched telecommunications or data transmission network, owned and/or maintained by a teleoperator or a mobile station operator, which is generally called by acronym CSN. In such CSNs, the technology is nowadays typically completely or almost completely digital, except for constantly decreasingly the last connection from the local switching centre to the user's terminal equipment. The switching centre or the interface server of the PLMN pertains to the CSN typically through the PLMN's gateway switching centre which may be a separate network unit or a part of the PLMN switching centre.

hi this application, data network means any such commercial or non-commercial packet switched data transmission network, usually owned and/or maintained by a teleoperator and/or mobile station operator, which is generally called by acronym PSN. hi such PSNs the data is routed to the target over the network packeted in relatively small units, that is, packets. Typically a PSN, such as Internet, intranet, X.25 network etc., pertains to the telecommunications network by an interface server. When applying CDM multiplexing for data transmission in PLMN, one employs one frequency channel the bandwidth of which one optimises. The original CDMA standard, which is also known as CDMA One, and which is still in general use in the United States of America, offers one-channel data transmission speed of even 14.4kbps, and offers eight-channel data transmission speed of even 115kbps. Also already known CDMA systems are CDMA2000 and wideband WCDMA system, with the means of which greater data transmission speeds can be offered. WCDMA is an ITU standard which is based on CDMA technology, which is officially known as IMT-2000. WCDMA is a third generation (3G) wireless communication technology the purpose of which is to offer mobile phones and other terminals greater data speeds than current ones. WCDMA technology is designed to support moving picture and data and video communication between LAN and terminal even at the speed of 2Mbps, and between WAN (Wide Area Network) and terminal even at the speed of 384kbps. The width of the WCDMA system frequency band is 5Mz, but the bandwidth in the narrow-band CDMA system is only 200kHz.

When applying TDM multiplexing for data transmission in PLMN, the terminal connects into one of many frequency channels for the time of data transmission, and data transmission takes place in the TDMA frame time slots of the frequency channel in question. Digital PLMN systems which apply TDMA are, for example:

GSM systems standardised by ETSI;

PCS systems according to EIA's (Electronic Industries Association) and TIA's (Telecommunication Industries Association) standards IS-95 and IS- 136; - D-AMPS systems; and

PDC systems defined by the Japanese RCR with 11 component and or system manufacturers.

hi TDMA systems, data transmission is thus typically based on time division multiplexing with the means of which the frequency channel(s) is(are) divided into time slots in order to transmit information at least on one frequency channel of the interface. For instance GSM system employs typically an eight-time-slot TDMA frame, and digital D-AMPS and PCD systems employ typically a three-time-slot TDMA frame. One must note, however, that different systems apply TDM technology in different ways, and are not compatible with each other.

Formerly is also known a GPRS system which applies TDM multiplexing and is standardised by ETSI and which is supported by, among others, GSM and PCS systems. With GPRS system, the capacity of data transmission over PLMN radio interface can be increased in the traffic channel which applies TDM technology, that is, in a frequency band. This increase of data transmission capacity is based on information packeting and information transmission in a time slot which has the data transmission capacity of 21.4kbps. It is also characteristic for GPRS system that there is a possibility to chain TDMA frame time slots, when packet information may be sent in successive time slots which each have the data transmission capacity of 21.4kbps. h theory by chaining all eight time slots, with GPRS system it is possible to obtain the maximum data transmission capacity of 171.2kbps. The problem of time slot chaining is, however, that chaining, correspondingly, decreases the possibilities to send information in TDMA frame between more terminals and base stations. If all TDMA frame time slots are chained, the problem is that the whole TDMA frame is reserved for data transmission between only one terminal and PLMN base station.

A common feature of GSM and GPRS systems is that they are narrow-band PLMN systems, and the bandwidth of their frequency channels, which form traffic channels, is constant.

Formerly is also known a system which was originally known by the acronym FPLMNS: its wireless traffic channels, or frequency bands, apply time-slot TDM multiplexing, and it is standardised by ETSI and known in Europe as UMTS. UMTS operates on the frequency of 2GHz, and in order to increase data transmission capacity, it is designed as a wideband system, although UMTS system does not replace GSM or GPRS system but must be considered their extension. The essential difference of UMTS system, when compared to GSM and GPRS systems, is that in UMTS the bandwidth of the frequency band is flexible, which enables greater data transmission capacity and is adequate, for example, for showing moving picture on terminal display or for Internet use.

Connected to TDMA applications, from FI patent 104676 is especially known an interface for WLL applications in which, with the means of many simultaneous frequency bands, data is transmitted between terminal and base station. From the same applicant's DE patent 3609395, is known the arranging of time slots of different lengths in a TDMA frame dependent on the modulation method.

FDM multiplexing generally means the allocation of the frequency band into 30 channels for wireless digital and/or analogue mobile communications, when in each channel speech and/or data may be transmitted. FDM is a basic technology of analogue AMPS system which is most widely employed in North America. When applying FDM multiplexing, each channel may in turn be arranged for one user only. FDM multiplexing is also employed in the English TAGS. Furthermore, the digital D-TACS applies FDM multiplexing, but, furthermore, also TDM multiplexing is employed so that one FDMA channel is able to accommodate n*3 channels, or, one channel is able to accommodate triple the users.

The basic general characteristic and, at the same time, a weakness and a problem related to the transmission of information of known PLMN systems adapted into practice and which apply xDM multiplexing was typically the fact that the systems are narrow-band networks in which the band employable for data transmission is minor. For example, in a GSM system which employs TDM multiplexing, there is only a band of 9.6kbps in use. Furthermore, in the GSM system in order to transmit information, the terminal locks into one traffic channel, or, frequency band, for the time of information transmission, and information is sent only in one time slot of this frequency channel at a time. The general object of the present invention is to aim to eliminate or at least essentially decrease the known telecommunications and data transmission linked disadvantages and weaknesses of PLMN system, to intensify data transmission over PLMN system, and to change the PLMN terminal into a virtual network workstation, with which one is able to remote control, utilise and employ telecommunications, data transmission and data processing resources over PLMN so that the application processing, information transmission and employment of resources over PLMN with a PLMN terminal essentially speeds up and intensifies.

The second object of this invention is to aim to intensify data transmission over PLMN system radio interface without excessive consuming of the band in a limited traffic channel or in xDMA frame of the traffic channel.

The third object of the present invention is to produce a new and inventive service entity for data network, such as LAN, WAN or X.25 or IP network, such as an Internet or intranet network, which connects over PLMN into telecommunications network, and/or for gateway switching device, which connects into telecommunications network switching centre in order to virtually allocate the resources of data network and/or gateway switching device for PLMN terminal(s) and in order to employ them with terminal(s).

These objects are accomplished with the previously mentioned data transmission system the general characteristics of which are illustrated in the characterising part of the enclosed patent claim 1.

According to the invention, the PLMN terminal is changed into a virtual network workstation which communicates with a resource server of telecommunications network or data network which includes at least an application or a disk server, and which virtual network workstation communicates with PLMN via a wireless interface the capacity of which is least 20kbps, and in which virtual workstation no application is processed, but from which virtual workstation only control and utilisation facilities, such as keystrokes and/or mouse clicks, are essentially transferred in the data transmission path from the virtual workstation over PLMN into the resource server, and the changed data, such as changed user interface or display data, is transferred in the data transmission path from the resource server over PLMN into the virtual workstation.

As information or data is transmitted over PLMN according to the invention, a data transmission system according to the invention may essentially be utilised regardless of the type of PLMN. It is, however, especially recommended that PLMN is chosen among the group including PLMNs applying TDM, FDM and CDM multiplexing in which the data transmission capacity of the wireless interface is at least 20kbps. Then information is transmitted packeted over a wireless interface applying xDM multiplexing. Most advantageous PLMN types are PLMNs applying TDM multiplexing, such as PLMNs in accordance with GPRS and UMTS standards. Then it is advantageous, according to the invention, that the interface employing TDM multiplexing includes at least one frequency band of fixed or changing bandwidth and a TDMA frame, in which interface the data transmission capacity of either one TDMA frame time slot of an individual frequency band or the many chained time slots of an individual frequency band or the many time slots of many simultaneous TDMA frame of parallel frequency bands is at least 20kbps. By chaining time slots, GPRS system is able to produce data transmission capacity from 20kbps to 171kbps.

In GPRS system, the number of successive data transmission time slots may be even eight. As a browser function implemented to the terminal requires only the data transmission capacity of 20-40kbps, the necessary data transmission capacity in GPRS can be obtained with either one TDMA frame time slot or with the chaining of two TDMA frame time slots. Then one TDMA frame of the traffic band is not allocated only for data transmission between one terminal and the PLMN base station, but the TDMA frame accommodates also other PLMN system users. The most significant difference of UMTS when compared to GPRS and GSM systems is that the UMTS traffic channel has a more flexible bandwidth which enables flexible data transmission capacity. Then it is confirmed that even in a single TDMA frame time slot, one is always able to transmit information with adequate speed for virtual allocation and remote control and use of the resources of the data system and/or data network.

As information or data is transmitted over PLMN according to the invention, the resource server according to the invention can be arranged to the data transmission path so that, with the data transmission system according to the invention, one is able to implement: a regional or an IP network solution, such as LAN, WAN, Internet, intranet etc. packet switched network, when the regional or IP network interface server pertains a resource server which is arranged for data transmission communication with a telecommunications network, such as PLMN or PLMN-linked fixed network, switching centre or gateway switching centre or interface server, a "service provider" service, such as Internet operator service, when the resource server is located in the service operator's data and/or network system and is arranged for data transmission communication with a telecommunications network, such as PLMN or PLMN-linked fixed telecommunications network, switching centre or gateway switching centre or interface server, or - a network operator's intelligent network service, when the resource server is advantageously arranged in the SCP point of the intelligent network or IN with which PLMN switching centre either communicates via IN's SSP switching point or is routed via PLMN gateway switching centre and possibly via fixed telecommunications network and IN's SSP switching point. One must note that SSP and SCP may be integrated into one SSCP switching and control point. Furthermore, the telecommunications or PLMN switching centre can be equipped or modified to operate as IN's SSP and/or SSCP switching and control point, when the telecommunications network's or PLMN's switching centre and IN's SSP switching point and SCP control point are integrated into one SSCP switching centre.

With the data transmission system according to the invention, one is also able to implement a network operator switching centre service, when the resource server is arranged as an element of a telecommunications network, such as a PLMN or a PLMN-linked fixed telecommunications network, which is advantageously in data transmission communication with the means of a fixed connection, for example, a cable or wireless link connection, with telecommunications network, such as PLMN or PLMN-linked fixed telecommunications network, switching centre or gateway switching centre.

The communication protocol for remote control and employment of the resource server pertaining to the data transmission system, according to the invention, in order to transmit control facilities, such as keystrokes and/or mouse clicks, and the changed data, such as changed user interface or display data, in the data transmission path between terminal and resource server, is advantageously a distributed presentation protocol supporting Windows, Unix, Linux or other operating systems. Most advantageously this communication protocol is an ICA communication protocol, such as advantageously Citrix¹"¹ ICA communication protocol, which is a communication protocol intended for Windows or Unix or Linux etc. environment which enables the fact that the changed data of the application running in the resource server is shown in the terminal at the same time as the application logic runs in the resource server.

The resource server is, according to one advantageous embodiment of the invention, a SBC server which comprises of at least an application server and a disk server in order to establish resources for utilisation in the terminal over PLMN. Such a SBC server is, most advantageously, a multi-user MetaFrame operation system and application server, advantageously a Citrix¹"¹ MetaFrame server, which is equipped with a Windows and/or Unix and or Linux terminal server, hi the SBC server, the SBC processing and SBC signalling is implemented with MetaFrame software, when the terminal only seems like an ordinary workstation, but between the terminal and the SBC server no application, windowing nor database data is transmitted, but with the means of the communication protocol, which is advantageously ICA communication protocol and most advantageously Citrix¹™ ICA communication protocol, essentially only the terminal keystrokes and/or other control facilities, such as mouse clicks, are sent from the terminal, and the terminal receives essentially only changed information/data, such as changed display or interface data. As the ICA communication protocol is implemented into system level, it is extremely effective and compact, when running applications, which usually demand wide bandwidth, almost in LAN speed is enabled over narrow-band PLMN and especially over its wireless interface.

One must emphasise that, instead of the above-mentioned examples of Citrix^ta MetaFrame server and Cirrix¹™ ICA communication protocol, one may naturally employ also other SBC servers and communications protocols which are designed for Windows and or Unix and/or Linux or other operation system environments and which are designed for SBC processing and signalling and telecommunications and/or data transmission via narrow-band traffic channel. For instance Tarantelum^ta is a commercial trade name for suitable SBC servers and communication protocols with the means of which one is able to produce both a data transmission system and a narrow-band traffic and interface, according to the invention, between PLMN terminal and resource server.

The advantage of the invention is that, with the means of SBC architecture, different data networks, such as LAN, WAN, Internet, x.25, intranet and similar networks and their resources, are acquired for remote use over PLMN in a PLMN terminal, when the terminal becomes a virtual network workstation via the resource server. As remote control and use is possible in the whole PLMN system service area(s) and/or coverage area(s), the data transmission system according to the invention is not positional but it is extremely flexible and adapts for changing needs. Furthermore, all connections linked to the data transmission system, such as the Internet, are in remote use, when because of SBC architecture, a traffic channel which has advanced data transmission capacity and an ICA communication protocol, the virtual network workstation is essentially or almost able to utilise the data transmission speed of a fixed interface. Especially connected to SBC and ICA technologies, one must emphasise that, with the means of them, one is able to overcome the limitations of narrow band, h addition to running applications, the user of the terminal, for example a GPRS terminal, is able to transfer data files and surf on the Internet with the connection speed with which the data network, such as LAN or Internet, links to the resource server, because the applications run entirely in the resource server, not the terminal.

On the advantages of the above-mentioned example of GPRS execution format, one can state that the GPRS technology, which can supplement current SMS short message services and CDS data transmission services, has many unique features because of which:

GPRS makes it possible to reach multiple data transmission capacity compared to GSM system, that is, theoretically the maximum of eightfold the data transmission capacity (171.2kbps) by the simultaneous employment of all eight time slots. Correspondingly, for example in D-AMPS systems the data transmission capacity can be increased into threefold with the invention,

When the GPRS terminal is in the service or coverage area of PLMN system, forming the connection is quick as information can be send or received as soon as required, - GPRS system facilitates the employment of new and old applications over

PLMN system network, as there is essentially more employable band than, for example, the 9.6kbps enabled by CSD used in GSM, and there is no limitation of 160 characters in SMS messages,

GPRS system does not limit the use of typical connectionless data transmission networks, such as IP or Internet networks, or applications, such as FTP, WWW browsing, Telnet etc., The GPRS terminal can be connected to be a part of the Internet network, and the GPRS terminal can also be assigned a dynamic IP address. Then, the IP' address pool unit is integrated into the resource server or gateway switching device.

The invention will next be explained as examples by way of its certain advantageous embodiments and by referring to the enclosed patent drawings in which FIG.l diagrammatically illustrates the first advantageous embodiment of the invention with the means of which both "service provider" and LAN and Internet network solution may be implemented, and

FIG.2 diagrammatically illustrates the second advantageous embodiment of the invention with the means of which the switching centre solution of the telecommunications network can be implemented.

As from Figures 1 and 2 becomes evident, the data transmission system according to the invention comprises of mobile phone or cellular radio network or PLMN network 3, and mobile stations 1, which communicate with PLMN 3 via wireless interface 2. PLMN 3 connects via its switching centre 33 or gateway switching centre 34 to the fixed telecommunications network 4 switching centre 41 or to telecommunications network interface server (not described) or to packet switched data network or resource server 8 of the data transmission system according to the invention.

Regardless of PLMN system type, PLMN 3 includes, in addition to PLMN switching centre(s) 33 and PLMN gateway switching centre 34, at least one base station system 31, 32, with the means of which the terminals 1, which are able to move in PLMN 3 service area service cells, communicate with PLMN 3 via the wireless interface 2.

As according to the basic idea of the invention information or data is transmitted over PLMN 3, the PLMN type can be chosen quite freely without compromising the invention's functionality. Thus, the invention may generally be applied into all such

PLMN systems, or radio or cellular radio systems, the radio paths of which, according to the invention, have the data transmission capacity of at least 20kbps for the interface 2. It is advantageous, according to the invention, to apply xDM multiplexing, such as TDM, CDM and/or FDM multiplexing, to form interfaces 2.

According to the basic idea of the invention, the interface 2, which applies xDM multiplexing, comprises of at least one traffic channel which has a fixed or changing bandwidth. Most advantageously xDM multiplexing is then TDM multiplexing.

The invention will next be explained in more detail, by way of certain especially advantageous embodiments illustrated in Figures 1 and 2. Then xDM multiplexing is represented by TDM multiplexing, and the PLMN system is a GPRS system.

In the embodiment according to the Figures 1 and 2, the GPRS network 3 comprises of at least one SGSN central processing unit 33 and a base station system, which comprises of at least one base station controller 32 and base stations 31, which base station 31 serves a cell of PLMN 3. h the coverage area of base station 31, the GPRS terminal 1 is mobile and able to be in data transmission connection with base station

31 via a wireless, TDM-based interface 2. The base station controller 32 and pertaining base stations 31 may exist in GPRS network either separately or integrated into one unit. In the embodiment according to the figure, the base station controller

32 and the base stations 31 are presented as separate units, and thus they constitute the base station system 31, 32 of the GPRS network 3.

As the interface 2 applies TDM multiplexing, the interface 2 comprises of at least one frequency channel of a fixed or changing bandwidth composed of TDMA frames. Thus, the data transmission capacity of one TDMA frame time slot of a single frequency band, or many chained time slots of a single frequency band, or many time slots of many simultaneous TDMA frames of parallel frequency bands of the interface 2, which optionally applies TDM multiplexing, is at least 20kbps. As the most advantageous embodiment of PLMN 3, which applies TDM multiplexing, is a GPRS network, the data transmission capacity of the wireless interface 2 between terminal 1 and GPRS 3 base station 31 is, depending on the number of chained time slots, between 20kbps and 171kbps.

To further explain the invention, one must state that the known server application systems apply one of the following principles:

In terminal application solution, all necessary software is saved on the terminal memory when the sole running of applications in the terminal is fast, but the updating of data received from the remote server into the terminal is slow and totally dependent on the data transmission capacity of the slowest connection, that is, on the data transmission capacity of the wireless interface in mobile solutions. - In terminal/server solution, terminal or client software is saved on the terminal, with the means of which one makes and sends necessary control commands to the server application, after which the server processes the request and sends the result back to the terminal. With this solution, one is only able to decrease the memory consumption of the software on the terminal, but the applications' processing and data access speed is slow, because the data access from the application to the terminal is entirely dependent on the transmission speed of the slowest single connection of the data transmission path between terminal and server, that is, in mobile solutions on the data transmission capacity of the wireless interface, and - In browser/network solutions, browser software, such as Netscape¹"¹ and

Microsoft Internet Explorer*¹¹¹, is saved on the terminal, with which one is able to browse and contribute to the server application. Technically, the browser software is terminal software which utilises connection protocol and makes inquiries to the server. The operation of the browser solution is slow as in browser solutions the basic principle is to send all inquiry data from the terminal and to receive all response data in the terminal, and because the data access from the application to the terminal is entirely dependent on the transmission speed of the slowest single connection of the data transmission path between terminal and server, which in mobile solutions, such PLMN systems, is the data fransmission capacity of the wireless interface.

As in the data transmission system according to the invention information or data is transmitted between terminal 1 and resource server 8, the connection from telecommunications network 3, 4, such as a PLMN and/or a fixed PLMN-linked network, switching centre 33 or gateway switching centre 34 or interface server (not shown) to the resource server 8, and vice versa, can be routed quite freely, that is, it is not essential how the data transmission path between the terminal 1 of PLMN 3 and the resource server 8 is arranged and what it is like. Thus, with the data transmission system according to the invention one is able to implement: a) an area or IP network solution, when the area or IP-type data network 5, 6, 7 is advantageously a LAN or WAN or Internet or intranet etc. packet switched network, and when the resource server 8 pertaining to the area or IP network interface server 51, 61, 71 is arranged into data transmission communication with a telecommunications network, such as a PLMN 3 or a fixed PLMN-linked network 4, switching centre 33, 41, which connections are illustrated in Figure 1 with an unbroken line, or with gateway switching centre 34, which connection is illustrated in Figure 1 with a line of dots and dashes, or with a interface server

(not shown), b) a "service provider" solution, for instance a service via an Internet or other service operator, when the resource server 8 is located in the service operator data and/or network system, which may be a computer system or, for example, an area or IP-type data network 5, 6, 7, and when the resource server 8, which pertains to the area or IP network 5, 6, 7 interface server 51, 61, 71, is in data transmission communication with a telecommunications network, such as a PLMN 3 and/or a fixed PLMN-linked network 4, switching centre 33, 41, which connections are illustrated in Figure 1 with an unbroken line, or with the PLMN gateway switching centre 34, which connection is illustrated in Figure 1 with a line of dots and dashes, or with a telecommunications network 3, 4, such as PLMN network 3 and/or a fixed network 4 linking to a PLMN network 3, interface server (not shown), c) an operator solution, in fact, a service via a telecommunications network operator, such as PLMN network 3 and or a fixed network 4 linking to a PLMN network 3, when the resource server 8 is arranged as an element of the telecommunications network 3, 4, which is in data fransmission communication with the means of a fixed connection, which can be implemented by a cable or wireless link, with the telecommunications network, such as PLMN 3 and/or a fixed PLMN-linked network 4, switching centre 33, 41, which connections are illustrated in Figure 2 with an unbroken line, or with the gateway switching centre 34 of PLMN 3, which connection is illustrated in Figure 2 with a line of dots and dashes, or, d) an IN solution, in fact, as an Intelligent Network or TN service (not shown) via a telecommunications network operator, such as a PLMN network 3 and/or a fixed network 4 linking to a PLMN network 3, when the resource server 8 is advantageously arranged in the IN (not shown) SCP control point (not shown), with which the PLMN 3 switching centre 33 communicates directly via an IN SSP connection point (not shown) or routed via PLMN 3 gateway switching centre 34 and IN SSP connection point or via a fixed telecommunications network 4 switching centre 41 and IN SSP connection point. The connection control from PLMN or telecommunications network to IN and back is advantageously managed with general SS7 signalling, hi addition, one must note that SSP and SCP can be integrated into one SSCP connection and control point. Furthermore, the telecommunications or PLMN switching centre 41 or 33 can be equipped or modified to function as the IN SSP and/or SSCP connection and control point, when the telecommunications network or PLMN switching centre and IN SSP connection point and SCP control point are integrated into one SSCP switching centre (not shown).

Establishing connections in telecommunications and data networks is familiar for persons skilled in the art as such, so it will not be explained in detail in this application at hand. The following is, however, mentioned. i. hi both internal and inter-network routing of TCP/IP protocol applying data networks, such as Internet, intranet and extranet, one typically employs routers and IP addresses. ii. In routing of area networks, such as LAN and WAN, one employs both routers and bridges. The essential difference between a router and a bridge is that the router recognises a network address of the third OSI level, for example, an IP address, but a bridge is only able to utilise addresses of the second OSI level, for example, MAC addresses. Furthermore, bridges do not support handshake protocols, such as ICMP employed by routers. For routing, one often nowadays uses bridge-router combinations, that is, so- called brouters. Area networks can be linked to each other via a modem connection of a bridge, router or two bridges. iii. Routing in telecommunications networks and PLMNs and between these networks and TN is typically based on sending the call dial-up of the desired destination or B connection, that is, the resource server 8, in the calling or A connection, that is, the terminal 1, when the call dial-up is routed from terminal 1 to resource server 8 via telecommunication network and/or PLMN and/or IN 3,4 nodes, such as switching centres 33, 34, 41 and SSP connection points, with the means of signalling. For signalling, one may use any CAS or CCS signalling designed for information or data transmission between nodes.

An advantageous CCS signalling designed for connecting between digital network nodes is the general SS7 signalling, which is standardised by ITU-T (friternational Telecommunication Union-Telecommunications standardization sector). This standardised SS7 signalling is mainly based on SCCP protocol and the levels 1 to 3 of OSI model, which include the physical level SDL, data link level SLF and network level SNF, and which together form a MTP, with which the SCCP protocol forms a NSP, which is thus formed of levels 1 to 3 of OSI model and the SCCP protocol linked with level 3.

According to the invention, the resource server 8 is a SBC server, advantageously a multi-user MetaFrame operation system server which advantageously supports at least Windows and Unix operation systems, when the connection protocol is advantageously an ICA connection protocol. Most advantageously the SBC server is a Citrix"¹¹ MetaFrame SBC server, and the connection protocol is correspondingly Citrix¹"¹ ICA connection protocol. Another SBC server functioning as MetaFrame operation system server is, for instance, Tarantellum¹"¹ MetaFrame SBC server, when the connection protocol is Tarantellum¹¹¹¹ ICA connection protocol.

In the first embodiment of the invention, illustrated in Figure 1, the resource server 8 is arranged into an area network, advantageously a LAN 5, the interface server 51 of which is in data transmission communication via a cable connection directly or via another telecommunications network 4, which is advantageously a fixed circuit switched network CSN or another PLMN, with PLMN switching centre 33, PLMN gateway switching centre 34 or another PLMN 3 linked telecommunications network 4 switching centre 41. Advantageously, the resource server 8 connects to the interface server 51 via a cable link, but the resource server 8 can also be integrated to be a part of interface server 51. One must notice that, in addition to or instead of locating it in LAN 5 interface server 51, the resource server 8 may be integrated with other packet switched data networks 6, 7 interface servers 61 and 71, as has been illustrated in Figure 1 with a broken line. Thus, the data transmission path from terminal 1 over PLMN 3 always extends, accordingly, to the resource server 8 located in the data network 6, 7 in question, such as Internet, intranet, WAN or corresponding PSN, which resource server 8 advantageously pertains, accordingly, to the data network 6, 7 interface server 61, 71. Thus, it is generally advantageous that, in this first embodiment of the invention, the PLMN 3 switching centre 33 or gateway switching centre 34 is directly in data fransmission communication with data network 5, 6, 7 via a direct cable link or another, for example fixed telecommunications network 4. Most advantageously, the resource server 8 is located between PLMN switching centre 33 or PLMN gateway switching cenfre 34 or another PLMN-linked telecommunications network 4 switching centre 41 or another PLMN 3 linked telecommunications network interface server and data network 5, 6, 7 interface server 51, 61, 71. In the second embodiment of the invention, in accordance with Figure 2, the resource server 8 is arranged as an element of a PLMN 3 or PLMN 3 linked circuit switched network CSN so that the resource server 8 is arranged in PLMN 3 and, in the data transmission path, from the terminal 1 over PLMN 3 to the resource server 8, with the means of a cable connection, to data fransmission communication either with PLMN switching centre 33 or PLMN gateway switching centre 34. After the mentioned data transmission path, from the terminal 1 over PLMN 3 to the resource server 8, the resource server 8 is arranged either via a cable connection or a network connection, for example via a circuit switched telecommunications network 4 illustrated in Figure 2, to data transmission communication with the packet switched data network 5 interface server 51, which data network is in the second embodiment of the invention, illustrated in Figure 2, an area network, most advantageously a LAN. Alternatively or in addition, such as also illustrated in Figure 2, the resource server 8 may be combined with another data network 6, 7, for example Internet, intranet, WAN or corresponding PSN, interface server 61, 71. Then the data transmission path extends from terminal 1 over PLMN 3, accordingly, to the resource server 8 located in data network 6, 7, such as Internet, intranet, WAN or corresponding PSN, which resource server 8 advantageously pertains, accordingly, to the data network 6, 7 interface server 61, 71. Thus, it is also generally advantageous that, in this second embodiment of the invention, the PLMN switching cenfre 33 or gateway switching centre 34 is in direct data transmission communication via a cable link or another, for example, fixed telecommunications network 4 with data network 5, 6, 7. Most advantageously, the resource server 8 is located between PLMN switching centre 33 or PLMN gateway 34 or another PLMN-linked telecommunications network 4 switching cenfre 41 or another PLMN 3 linked telecommunications network interface server and data network 5, 6, 7 interface server 51, 61, 71.

According to the invention, it is advantageous to connect the resource server 8 via a cable link connection or wireless link connection to the PLMN 3 switching centre 33 or gateway switching centre 34 or another PLMN-linked telecommunications network 4, for example CSN, switching centre 41. In order to offer as many as possible utilisable resources over PLMN 3 to the virtual network workstation 1 or PLMN 3 terminal with the means of the resource server 8, it is advantageous, according to the invention, that, at the minimum, the resource server 8 comprises of application server 81 and disc server 82. In the advantageous embodiments of the invention according to both Figures 1 and 2, a connecting and browser application, for example Netscape*¹" or Microsoft Internet Explorer*"¹, is implemented in the resource server 8 application server 81, when with the resource server 8 one is able to utilise besides the resources of the area and/or data network 5, 6, 7 in question also other resources linked to the interface server 51, 61, 71 of the area and or data network 5, 6, 7 in question, such as Internet network.

Most advantageously, the resource server 8 is arranged as a network element of PLMN 3, or the resource server 8 pertains to the telecommunications network 5, 6, 7 interface server 51, 61, 71, which data network is linked directly via a cable connection or via another telecommunications network, such as fixed CSN, to the PLMN 3 switching centre 33 or gateway switching centre 34. Then with the means of the data fransmission system according to the invention, one is able to utilise virtually all data network 5, 6, 7 resources in the terminal 1 via the data transmission path between the resource server 8 and PLMN terminal in addition to the resource server 8 application and disk resources.

According to the invention, the resource server 8 is implemented utilising SBC architecture with a SBC server. SBC server is advantageously a multi-user MetaFrame operation system server, which supports at least Windows, Unix and

Linux operation systems, most advantageously SBC server is a Citrix*™ SBC server.

In the multi-user SBC MetaFrame operation system server, all SBC processing and

SBC signalling is implemented with MetaFrame software arranged in SBC server 8.

In order to support, for example, Windows and/or Unix and/or Linux operation environment, the SBC server 8 includes, accordingly, Windows and/or Unix and/or

Linux terminal server(s), which is/are equipped with Citrix*¹" MetaFrame software.

Then PLMN terminals 1 are and seem to be ordinary workstations, but no application, windowing or databank data moves between the terminal and SBC server 8, when the terminals 1 are genuinely virtual network workstations. Only terminal 1 keystrokes and/or other control facilities, such as mouse clicks, are transferred to the SBC server 8 via the data transmission path between terminal 1 and SBC server 8. In SBC processing, also only the changed parts of the terminal 1 display are updated. Such operating principle enables operating in an extremely small data fransmission band. Because of SBC processing, only 20kbps of band is needed for each terminal 1 over the radio interface between terminal 1 and base station 31, when, for example, one time slot of GPRS system TDMA frame, which is 21.4kbps, or, for example, one time slot of UMTS system wideband TDMA frame is enough for virtual on-line remote work with a data system and/or resources pertaining to a fixed network.

The protocol component designed for remote control and use of data network 5, 6, 7 pertaining to the data transmission system, according to the invention, for transferring control facilities, such as keystrokes and/or mouse clicks, and changing data, such as changing user interface or display data, in the data transmission path between terminal 1 and resource server 8 is the above mentioned ICA connection protocol, advantageously a distributed Windows, Unix, Linux or other operating system presentation protocol. The ICA connection protocol enables the fact that the application user interface is shown on the terminal 1 display at the same time as the application runs in the multi-user resource server 8, which is advantageously a SBC server, such as MetaFrame server. An advantageous MetaFrame server is, for example, Citrix*¹" or Tarantellum*"¹ MetaFrame server. Because the ICA connection protocol is implemented into system level, it is exfremely effective and compact, when the running of applications, which usually demand wide bandwidth, at almost

LAN speed is enabled over interface and telephone lines.

The following abbreviations were used in this patent application:

PLMN Public Land Mobile Network SGSN Serving GPRS Support Node LAN Local Area Network WAN Wide Area Network TCP Transmission Control Protocol ΓP Internet Protocol

CAS Channel Associated Signalling

CCS Common Channel Signalling

VAS Value Added Services

CDM Code-Division Multiplexing TDM Time-Division Multiplexing

FDM Frequency-Division Multiplexing

CSN Circuit Switched Network

PSN Packet Switched Network

CDMA Code-Division Multiple Access WCDMA Wideband Code-Division Multiple Access

TDMA Time-Division Multiple Access

FDMA Frequency-Division Multiple Access

ETSI European Telecommunications Standards Institute

GSM Global System for Mobile communications PCS Personal Communications Services

D-AMPS Digital- American Mobile Phone System

AMPS Advanced Mobile Phone Services

PDC Personal Digital Cellular

GPRS General Packet Radio System FPLMNS Future Public Land Mobile Network System

UMTS Universal Mobile Telecommunication System WLL Wireless Local Loop TAGS Total Access Communication System D-TACS Digital-Advanced Mobile Phone Service ICA Independent Computing Architecture SBC Server Based Computing SMS Short Message Service CSD Circuit Switched Data FTP File Transfer Protocol WWW World Wide Web ΓN Intelligent Network

SCP Service Control Point SSP Service Switching Point

SS7 Signalling System 7

OSI Open System interconnection MTP Message Transfer Part

SCCP Signalling Connection Control Part

NSP Network Service Part

SDL Signalling Data Link

SLF Signalling Link Functions SNF Signalling Network Functions

ICMP Internet Control Message Protocol

MAC Media Access Control

The invention was only explained above by way of its alternative examples of application and by way of its certain advantageous embodiments. Naturally, this is not to limit the invention at hand to apply to only such individual embodiments. Indeed, as is evident to the persons skilled in the art, many alternative applications and variations are possible within the scope of the frames of the new and inventive idea, defined in the accompanying claims.

Thus, from the point of view of the functionality of the invention, it is not extremely relevant which type the PLMN is or how the resource server 8 is arranged to the data transmission path, that is, if the resource server 8 connects to the PLMN 3 switching centre/gateway switching centre 33/34 via cable contact(s), satellite or other wireless link(s), PSN(s) or CSN(s) 4.

Claims

1. A data transmission system for sending information or data over mobile communication or cellular radio or PLMN network (3) into PLMN (3) with the means of wireless interface (2) from connecting terminal (1), such as mobile station or pocket computer or portable computer, and back, which PLMN (3) is optionally in telecommunications and/or data transmission communication advantageously with packet switched data network (5, 6, 7), such as LAN, WAN, Intranet, X.25, IP network etc., characterised in that, in order to change PLMN (3) terminal (1) into a virtual network workstation, PLMN (3) pertains a resource server (8), which is in data transmission communication directly or via another telecommunications or data network (4, 5, 6, 7) with PLMN (3) switching centre (33), that resource server (8), which includes at least an application server (81) and a disk server (82), is located in data transmission path which extends from terminal (1) over PLMN (3) into resource server (8), that in data transmission path the data transmission capacity of interface between terminal (1) and PLMN (3) base station (31) is at least 20kbps, and that resource server (8) remote control and remote use devices include a connection protocol between terminal (1) and resource server (8), with the means of which essentially only control and use facilities, such as keystrokes and/or mouse clicks, are transmitted from terminal (1) over PLMN (3) to resource server (8), and changed data, such as changed user interface or display data, is transferred from resource server (8) over PLMN (3) to terminal (1).

2. A data transmission system according to Claim 1, characterised in that resource server (8) is arranged into data transmission communication with a data network (5, 6, 7) and with either a) a fixed telecommunications network (4) switching centre (41) or interface server, or b) a PLMN (3) switching cenfre (33) or gateway switching centre (34).

3. A data transmission system according to Claims 1 and/or 2, characterised in that resource server (8) is arranged into PSN network (5, 6, 7), via the interface server (51, 61, 71) of which is arranged a data transmission contact directly or via another telecommunications network (4), advantageously via a fixed telecommunications network (4), into PLMN network (3), advantageously into PLMN (3) switching centre (33) or gateway switching centre (34).

4. A data fransmission system according to Claims 1 and/or 2, characterised in that resource server (8) is arranged between PLMN (3) linked fixed telecommunications network (4) switching centre (41) or interface server and data network (5, 6, 7) interface server (51, 61, 71).

5. A data fransmission system according to Claims 1 and/or 2, characterised in that resource server (8) is linked with the means of a cable link connection or wireless link connection into PLMN network (3) or CSN network (4) switching centre (33; 41) or PLMN (3) gateway switching centre (34).

6. A data fransmission system according to any of the preceding Claims, characterised in that resource server (8) is a SBC server, which includes at least an application server (81) and a disk server (82).

7. A data transmission system according to Claim 6, characterised in that SBC server (8) is a multi-user operation system server, which advantageously includes Windows, Unix and/or Linux or corresponding terminal server(s).

8. A data transmission system according to Claims 6 and/or 7, characterised in that, in SBC server (8), SBC processing and SBC signalling is accomplished by SBC software implemented into SBC server so that terminal (1) is and seems like an ordinary workstation, but between terminal (1) and SBC server (8) no application, windowing nor database data is transmitted, but with the means of ICA communication protocol between terminal (1) and SBC server (8) the following information is transferred: from terminal (1) into SBC (8) terminal (1) keystrokes and/or other control facilities, such as mouse clicks, and from SBC server (8) into terminal (1) changed user interface or display information.

9. A data transmission system according to Claims 7 and 8, characterised in that SBC server (8) and ICA connection protocol are intended for Windows, Unix, Linux etc. operating system environment in order to implement SBC processing in SBC server (8) and in order to implement telecommunications and/or data transmission between SBC server (8) and terminal (1) via a narrow-band wireless interface (2).

10. A data transmission system according to any of the preceding Claims 1-9, characterised in that, in order to produce a narrow-band data transmission system and interface (2) between terminal (1) and resource server (8), resource server (8) has been chosen from among multi-user SBC servers, which include Citrix*"¹, Tarantellum*¹¹¹ and corresponding operating system and application servers intended for Windows, Unix, Linux etc. operating system environments and applying multiuser SBC architecture, and that ICA communication protocol intended for data transmission between resource server (8) and terminal (1) is a distributed Windows, Linux and Unix and/or corresponding operating system based presentation protocol, which is chosen from among a group which includes Citrix*¹", Tarantellum*¹" etc. ICA communication protocols intended for data transmission via a narrow-band data transmission band.

11. A data transmission system according to any of the preceding Claims, characterised in that data transmission capacity of data transmission communication, which is based on optional protocol, between a) data network (5, 6, 7) interface server (51, 61, 71) and resource server (8), or b) telecommunications network (3, 4) switching centre (33, 41) or PLMN gateway switching centre (34) and resource server (8) is between 64kbps and n*2Mbps.

12. A data transmission system according to any of the preceding Claims, characterised in that, in order to share and utilise data network (5, 6, 7) resources (81, 82) virtually with terminal (1), between terminal (1) and PLMN (3) base station (31) only control commands and changed user interface data of computer network (5) and/or data transmission system(s) chosen on terminal (1).

13. A data transmission system according to any of the preceding Claims, characterised in that terminal (1) is a virtual network workstation utilising resource server (8) in data transmission communication with PLMN network (3).

14. A data transmission system according to any of the preceding Claims, characterised in that wireless and digital interface (2) of terminal (1) into PLMN (3) base station (31) for data transmission applies multiplexing for transferable information, which was chosen from among a group which includes FDM, CDM and TDM multiplexing.

15. A data transmission system according to Claim 14, characterised in that interface (2) applying xDM multiplexing includes at least one traffic channel of fixed or changing bandwidth, and that data transmission capacity of interface is at least 20kbρs.

16. A data transmission system according to Claims 14 and/or 15, characterised in that interface (2) applies TDM multiplexing, which includes at least one frequency band of fixed or changing bandwidth composed of TDMA frame, in which interface data transmission capacity of either one TDM frame time slot of an individual frequency band or many chained time slots of an individual frequency band or many time slots of many simultaneous TDMA frame of parallel frequency bands is at least 20kbps.

17. A data transmission system according to any of the preceding Claims 14-16, characterised in that PLMN network (3) is a GPRS, and that data transmission capacity of wireless interface (2) between terminal (1) and PLMN base station (31) is between 20kbps and 171kbps.

18. A data transmission system according to any of the preceding Claims 1-17, characterised in that resource server (8) optionally: is located in IN network, which pertains to PLMN network (3) and/or telecommunications network (4), - is located in data network (5, 6), when resource server advantageously pertains to data network (5, 6) interface server (51, 61), is located in TCP/IP network (7), when resource server advantageously pertains to TCP/IP network (7) interface server (71), is a network element of PLMN network (3) or fixed telecommunications network (4) linked to PLMN (3), when there is a fixed connection between resource server (8) and PLMN (3) switching centre (33) or PLMN (3) gateway switching centre (34) or telecommunications network (4) switching centre (41).