WO2006027367A1

WO2006027367A1 - Data communication system and data communication method

Info

Publication number: WO2006027367A1
Application number: PCT/EP2005/054411
Authority: WO
Inventors: Kai Lauterjung
Original assignee: Kai Lauterjung
Priority date: 2004-09-10
Filing date: 2005-09-07
Publication date: 2006-03-16
Also published as: DE102004043868B4; DE102004043868A1

Abstract

The invention relates to a data communication method and a data communication system comprising at least one client (1) and at least one server (2). Said method and system are characterized in that a device is provided by means of which objects that are displayed on a client (1) screen are controlled in accordance with object control data received from the server (2).

Description

description

Data communication system, as well as data communication methods

The invention relates to a data communication system, in particular a data communication system having at least one, in particular a plurality of clients, in particular client computers, and having at least one server, in particular server computer.

In particular, the invention relates to a system and a method for reducing the volume of traffic and for reducing delay times for applications that are used on a client computer that serves as the input and output device for the applications and directly or indirectly via a mobile network and / or a line-based network, which is characterized in that it has a total high signal delay (of> 50 ms, for example), is connected to an application server, which executes the actual application and connected via the network client computer (terminal) for input and output , as well as display of program controls (eg selection menus), data and graphics uses.

The transmission capacities of mobile networks and terrestrial wide area networks are constantly being expanded and expanded. In addition to voice or messaging services, this now also enables the use of mobile data transmissions for applications in the private and business customer sector.

The high coverage and mobile availability of the connection to networks also opens up new possibilities for solutions in the client / server application area. An example of this are application servers in which a server executes the applications for several clients connected via a network in a central data center. The Clients serve only as input (mouse, keyboard, etc.) or output device (screen / printer, etc.). An example would be the architecture Microsoft Application Server.

The advantage of a client server solution is that you can centralize the administration and investment costs of a software solution and thus save costs. In addition, expensive HW investments can be shared by many, and the security level increases with centralized administration.

The communication between an application client and an application server computer is characterized by a constant exchange of data between the two devices.

The input of the user of the client will be used

(e.g., keyboard input or mouse movement) to the server. Data, graphics or control signals used for

Display the application transmits the server over the network to the application client.

The previously available solutions were based on the assumption that the signal runtime of the network is low, so the user gets a refreshed display of the screen relatively quickly after entering a character, which is transmitted from the client to the server, the server to the client via the network Computer transfers.

For networks with high delay time, the previous methods lead to problems. Due to the high signal transit times, the user only gets delayed reactions to his

Inputs are displayed. Thus, e.g. when clicking on a pull

Down menus, which makes multiple interactions between the client and the server necessary, possibly only several seconds later by opening the menu, the reaction to the client are displayed. This sometimes leads to an effective work with the application is impossible. One Another problem is that in networks with high costs for data volume, very high costs for the connection of the remote input-output units (terminals) incurred.

Accordingly, it is an object of the present invention to provide a method with which the effects of the latency of a mobile network and / or a terrestrial network on an application that is executed on a central server and for inputs and outputs with a via mobile - and / or terrestrial network connected client terminal communicates, eliminated or largely reduced, so that a comfortable operation for the user with the application is possible, and the data volume transmission costs for the user can be significantly reduced.

This object and / or further objects is or are achieved according to the invention by the subject matter of claims 1 and 9.

Further, advantageous embodiments of the invention are specified in the subclaims.

According to the inventive method for eliminating or reducing the effects of the latency of a mobile network and / or a terrestrial network on an application and to save data volume in the necessary for the execution of an application communication is a client computer with a server computer via a mobile network and / or a terr. Network, the client computer (terminal) only for input and output of data and information (eg via a keyboard, a mouse, a screen or printer) is used. The program code, the application used by a user on the client computer, is executed on the server accessible via the network server. The client server architecture according to the invention described here can, however, not have to be characterized in that methods already known and generally used in data communication in the satellite sector for optimizing the data flow between a client and a server via a time-delayed satellite network now also via a mobile radio network and / or a terrestrial network can be used. Software and hardware-based solutions for avoiding acknowledgment messages of received / transmitted data packets (avoidance of acknowledgments (ACKs), for example through the use of enhanced TCP) for the conversion of TCP into UDP are among the methods already known and generally used in the satellite sector UDP tunneling, optimizations of the MTU (Maximum Transfer Unit of a data packet), removal of redundancies in a data sequence (for example by compression), avoiding repeated transmissions of frequently transmitted information (for example by local storage of the data in the memory, automatic data transfer) Detection and caching).

FIG. 1 shows by way of example a network architecture according to an exemplary embodiment of the present invention, wherein corresponding client computers 1 are connected to one or more application servers 2 via corresponding mobile radio and / or territorial networks 3.

In the case of the network architecture according to the invention, at the location of a client computer 1 there can be additional suitable software or hardware (referred to below as SI) which calculate the screen representation or parts of the screen representation of the client computer 1 in the same manner as in an application server 2 and can control by signals.

At the location of the client computer 1 there may be an object database that is capable of parts of Display screen representations (objects), such as pixels, lines, graphics, menus, etc., as well as correlations of input sequences to the objects. Sl has access to the object database.

At the location of the server computer 2, there may be additional suitable software or hardware (referred to below as S2) which examines the data sent by the server computer 2 to the client computer 1 as to whether it contains signaling data which causes a change in the screen display which has already been controlled by Sl. In this case, S2 has been informed of the changes already processed by Sl by a message from Sl transmitted to S2 via the network 3.

The data communication between the client computer 1 and the server computer 2 can additionally be optimized as follows: The inputs for the application program (eg keystrokes, mouse movements or clicks) are already examined by SI to see whether they change the screen display on the client computer to lead.

If this is the case, then Sl examines which data and objects are needed to change the screen display, such as:

• Graphics / bitmaps

• Icons • various window types

• lines

• Frame

• Backgrounds

• shades • pull down menus

• Menu selection boxes and their possible entries

• Check mark, points, selection elements • Characters or letters in the form of different fonts

• And any number of other freely definable graphic elements

are present in the local object database to be able to locally calculate the change or parts of the change in the screen display without information from the central server computer 2, taking into account the current inputs by Sl. In this case, the size or the position of individual screen elements can be recalculated by Sl. The locally possible changes, ie changes in the screen representations, which thus require no data transmission or control by the central server 2, are signaled locally by the client computer 1 by Sl, who then displays these changes to the screen display virtually without a time delay. This signaling takes place in the same way as normally the central server computer 2 performs against the client computer 1 via the network 3. Thus, for example, the changed position of the mouse pointer by a movement input of the mouse, or the display of a menu after clicking or moving a window, etc. can be displayed immediately.

According to the inputs of the client computer 1, as otherwise also forwarded via the network 3 to the central server computer 2 parallel to this process. In addition, S2 is informed by Sl via the network 3, which changes the screen display on the client computer 1 have already been made by Sl. The answers of the server computer 2 to the inputs to the client computer 1 are then examined as to whether they contain control data or signaling information that should cause changes to the screen display on the client computer 1, which have already been controlled by Sl. To avoid duplicate signaling, these data and signals already filtered out by Sl and not transmitted via the network 3 to the client computer 1. This achieves a significant reduction in the data transport volume normally caused by the application.

In a further embodiment of the method, the client server architecture according to the invention (supplemented by S 1 and S 2) is extended to the effect that additional suitable software or hardware (referred to below as S 3) is used for the automatic creation of the object database. S3 examines the data stream sent by the client computer 1 for frequently repeated input combinations as well as the reactions of the server computer 2 received shortly afterwards via the network to screen signalisations. Correlations are derived from these investigations and stored in the object database. Thus, the object database is automatically filled with information (trained) that allow Sl to automatically calculate changes in the screen representations and to locally control the screen display or parts of the representation of the client computer 1 accordingly.

In the network architecture shown in FIG. 1, in the communication between client computer 1 and server computer 2 (and vice versa), data first generated by the respective client computer 1 (or server computer 2) for communication with the server computer 2 (or client computer 1) - Packages - eg Transmission Control Protocol (TCP) data packets - into corresponding data packets of a different protocol, e.g. converted into corresponding UDP packets, and these - via the o.g. Network 3 - to the server computer 2 (or the client computer 1) are transmitted.

Correspondingly vice versa can - from the respective server computer 2 (or client computer 1) - received from the client computer 1 (or from the server computer 2) data packets - eg the og UDP data packets - are converted into corresponding data packets of a different protocol, eg - back - into corresponding TCP data packets.

According to the TCP protocol, it is provided that the (correct) reception of each individual data packet by the respective recipient is (re) confirmed to the respective sender - the UDP protocol, by contrast, does not provide any corresponding (re) acknowledgment mechanisms.

In the present embodiment, instead, e.g. in each case before or after a predetermined number of UDP packets exchanged between the client computer 1 and server computer 2, the number of transmitted or subsequently transmitted packets (ie the number of packets of a "packet series") is transmitted With each package, data can be transmitted which identify the number of packages within the respective package series, which can be used by the respective recipient (ie client 1, or server 2) to determine whether an application is being used Package - and if so, which - did not arrive or did not arrive correctly.This package can then be requested - one at a time - thus ensuring that no data is lost within the network architecture without a complex (back) confirmation mechanism.

In addition to the above explanations, in order to restrict unnecessary data traffic to and from the server computer 2 in certain cases explained below, in these cases only or as large a proportion of user data as possible can be transmitted. For this purpose can be examined by the server computer 2 to the client computer 1 screen contents to be transmitted on the server computer 2, whether they can not be replaced by a suitable coding. The

Screen contents are usually represented as objects, eg comboboxes, or fields to fill in, which then unique, be assigned to the client computer 1 to be transmitted codes. The objects are present in the operating system of the client computer 1, as long as they are not application-specific objects that have to be made available to the respective client computer 1 (more precisely: S1) by customizing by S3. In the present embodiment, the computer 1 is advantageously no longer provided by the server computer 2 with the "screen" or the entire data of the central application initiating a corresponding display on the screen, instead the client computer 1 is only informed as to which objects The objects are then filled locally on the client computer 1, and the server computer 2 is only informed of the new data entered, which has two advantages: a) The the amount of data transferred is essentially reduced to the actual payload data, and b) the delay between an input and the response of the server computer 2 is reduced.

Claims

claims

1. Data communication system, characterized by at least one client (1), and at least one server (2), characterized in that a device (S1) is provided with which objects displayed on a screen of the client (1) in dependence on the server (2). received object control data are controlled.

2. Data communication system according to claim 1, wherein on the objects corresponding payload data in the client (1) can be entered.

3. Data communication system according to claim 2, wherein only the input user data, but not other objects characterizing data from the client (1) to the server (2) are transmitted.

4. Data communication system, in particular according to one of the preceding claims, wherein at the client (1) input control data, which are to cause a change in the representation of the objects on the screen of the client - without prior interposition of the server (2), or without waiting for a response from the server (2) - effect a modified representation of the objects on the screen of the client (1).

5. Data communication system according to one of the preceding claims, wherein the client (1) or the device (Sl) and the server (2) are wirelessly connected to each other.

6. Data communication system according to one of the preceding claims, wherein the communication between the client (1) or the device (Sl) and the server (2) under Use of data packets corresponding to the UDP protocol takes place.

A data communication system according to claim 6, wherein upon transmission of the UDP packets an identifier is transmitted indicating how many UDP packets belong to a UDP packet series to be transmitted.

A data communication system according to claim 7, wherein upon transmission of a UDP packet an identifier is transmitted indicating the number of UDP packets of a respective UDP packet series.

9. data communication method, in particular for use in a data communication system with at least one client (1), and at least one server (2) according to one of claims 1 to 7, characterized in that on a screen of the client (1) objects shown in dependence on Server (2) received object control data to be controlled.