DE10143064A1 - Component-based ad hoc network service - Google Patents

Abstract

The invention proposes to create a central component repository (CR) which implements a query language (QE) with which the components of a requested service can be found which best meet the needs of the user. The selection is made via the meta information registered with the service. By decoupling the service (3) and interface (4) into several components and their precise description in the collaboration, new scenarios are possible, such as: B. the automatic installation of part or all of the service on an additional network participant, which provides the necessary resources. As a result, a service is also available on a terminal device which itself does not have the required resources. Services that are not required are unloaded again and resources saved.

Description

The invention relates to a method for making available a service in a network on a network participant, who originally had no knowledge of the configuration and possibly also no knowledge of the existence of this service has, especially on a device that is connected to the network is connected, as well as a corresponding network structure.

In distributed systems, especially when using Devices with limited resources (e.g. less Network bandwidth and low memory) like a cell phone, a Personal digital assistant PDA etc. for users of the Desire to use services in a network (satellite and Base stations included) to use spontaneously, without prior notice To have known existence and configuration.

The problem also arises that due to Limitations such as lack of memory, CPU time and bandwidth such services not at the same time or not at all on the Device can be executed. Especially with regard to future digital networks based on UMTS (Universal Mobile Telecommunication System) with new memory-intensive There is a great need to solve the problems here outlined problem. It can also be assumed that future networks will offer even more complex services who will experience this problem even more.

No solutions to this problem are known to date become. Most of the scenarios are also future behaviors due to lack of technology were previously inconceivable.

The object of the present invention is therefore a To create a process that is desired by network participants Services available without knowing their configuration makes. Above all, this should also be possible spontaneously.

According to the present invention, this object is achieved by a Method of the type mentioned solved by a Decoupling from the service and the associated Access information is provided and, if necessary, the service on one Network participants or a plurality of network participants implemented with the required resources while the access information to the person accessing the service Network participants is made available.

It is advantageous if the information about the Decoupling of service and access information centrally in the Network is held. This can take the form of a own network unit, a so-called component Administration.

• - der Dienst bei einer Komponenten-Verwaltung des Netzwerks registriert wird und sofern über das Endgerät dieser Dienst angefordert wird
• - der Dienst von der Komponenten-Verwaltung aufgeteilt wird und
• - eine Dienst-Implementierung auf einem anderen Netzwerkteilnehmer erfolgt, welcher über die erforderlichen Ressourcen verfügt, während
• - die Zugriffsinformation des Dienstes einschließlich der Adresse dieses anderen Netzwerkteilnehmers dem Endgerät zur Verfügung gestellt wird, worauf
• - das Endgerät mit Hilfe der Zugriffsinformation auf den Dienst auf dem anderen Netzwerkteilnehmer zugreift.

In order to make a service available on a terminal device that is connected to this network, the following procedure is proposed:

• - The service is registered with a component management of the network and if this service is requested via the terminal
• - the service is divided by the component management and
• - A service implementation takes place on another network participant who has the necessary resources during
• - The access information of the service including the address of this other network participant is made available to the terminal, whereupon
• - The terminal accesses the service on the other network participant using the access information.

• - der Dienst bei einer Komponenten-Verwaltung des Netzwerks registriert wird und sofern über das Endgerät dieser Dienst angefordert wird
• - über die Komponenten-Verwaltung geprüft wird, ob das Endgerät über alle erforderlichen Ressourcen verfügt,
• - falls ja, der komplette Dienst über die Komponenten- Verwaltung auf dem Endgerät installiert wird, oder
• - falls nein, der Dienst von der Komponenten-Verwaltung aufgeteilt wird und eine Dienst-Implementierung auf einem anderen Netzwerkteilnehmer erfolgt, welcher über die erforderlichen Ressourcen verfügt, während die Zugriffsinformation des Dienstes einschließlich der Adresse dieses anderen Netzwerkteilnehmers dem Endgerät zur Verfügung gestellt wird, worauf das Endgerät mit Hilfe der Zugriffsinformation auf den Dienst auf dem anderen Netzwerkteilnehmer zugreift.

If there is a possibility that such a terminal may have the necessary resources for at least some of the available services itself, but should be able to access all available services, the following specialized procedure is preferred:

• - The service is registered with a component management of the network and if this service is requested via the terminal
• - Component management is used to check whether the end device has all the necessary resources,
• - if yes, the complete service is installed on the device via the component management, or
• - if no, the service is divided by the component management and a service implementation is carried out on another network subscriber who has the necessary resources, while the access information of the service, including the address of this other network subscriber, is made available to the terminal, whereupon the terminal accesses the service on the other network subscriber with the aid of the access information.

On the other hand, the resource requirements of a service should be so great be that none of the available network participants alone about the resources required to implement the service , it has proven to be advantageous if through the Component management a distribution of service Implementation on several other network participants he follows.

In order to save scarce resources, there is another advantageous embodiment of the method according to the present Invention proposed that services no longer needed from the respective end device and the respective Network subscriber on which the service or parts of a service implemented, unloaded.

According to a further advantageous embodiment, the Access information that a network participant, in particular a terminal device, Service interfaces and proxies.

A person skilled in the art understands a proxy as Information technology the term for services that replace the actual function for other network elements. This makes it possible, for example, to implement safety functions realize. Proxy agents that enable proxy services are often used at interfaces between networks and allow only a defined set of operations. For the They appear transparent to users. A so-called proxy Server takes over the provision of data, programs etc. for more distant servers. Only when the on the Proxy server data is not that of the client received requested data, it is necessary to the real, far to access remote servers. In this sense it is also possible with the invention instead of on the service itself, to access an associated proxy that is as above described works.

It has also proven to be beneficial if one Linking and / or a configuration of a service and the associated access information takes place via meta information, which is on the component management side. Under the The term meta information is understood to mean "data about other data ", for example in databases and the like Systems for the management of stored user data intrinsic data that is used to manage the actual User data can be used. The exact structure of the metadata is depending on the specific application. Metadata and User data do not always have to be in the same storage systems be filed. Depending on the application, it may be useful to Having metadata quickly available and the user data to keep decentralized on so-called background memories.

So-called. Are particularly suitable for describing this meta data. XML descriptors. XML stands for "Extended Markup Language "and is a label for a subset the language SGML for the description of pages in the World Wide Web WWW. It is in contrast to the more popular HTML (Hypertext Markup Language) possible that the author of an XML Document in the document itself certain extensions of XML in the so-called Document Type Definition part of the document defined and also used in the same document. While HTML is one Page description language, XML can thus be considered a Data description language are called.

If the accessing network participant also does not Has knowledge of the existence of the service this in connection with the original task by the Invention also solve by finding the service by the requesting network participant, in particular by the end device, via a query language that is in the Network is provided, especially centrally via the Component management, with a selection about using the Service registered meta information is done.

It has a further advantageous form proven to be favorable if the service is always installed, the associated meta information of an access request on best matches.

• - mindestens einen Dienste-Anbieter,
• - eine Komponenten-Verwaltung, bei der alle verfügbaren Dienste durch Meta-Information registriert sind und die eine Abfragesprache bereitstellt, über die Dienste oder Komponenten solcher Dienste anhand der zugehörigen Meta-Information auffindbar sind,
• - einem Endgerät, mit dem zum Zugriff auf einen Dienst über die Abfragesprache auf die Metainformation der Komponenten- Verwaltung zugreifbar ist, und
• - einem weiteren Netzwerkteilnehmer, der über ausreichende Ressourcen zur Implementierung eines Dienstes verfügt und auf den durch das Endgerät zugreifbar ist.

Furthermore, the object of the invention is achieved by a network structure with a plurality of network subscribers which corresponds to the inventive method described above, these network subscribers comprising the following components:

• - at least one service provider,
• component management in which all available services are registered by meta information and which provides a query language via which services or components of such services can be found on the basis of the associated meta information,
• a terminal with which the meta information of the component management can be accessed via the query language in order to access a service, and
• - Another network participant who has sufficient resources to implement a service and is accessible by the terminal.

• - mindestens einen Dienste-Anbieter,
• - eine Komponenten-Verwaltung, bei der alle verfügbaren Dienste durch Meta-Information registriert sind und die eine Abfragesprache bereitstellt, über die Dienste oder Komponenten solcher Dienste anhand der zugehörigen Meta-Information auffindbar sind,
• - einem Endgerät, mit dem zum Zugriff auf einen Dienst über die Abfragesprache auf die Metainformation der Komponenten- Verwaltung zugreifbar ist, und
• - einer Gruppe von weiteren Netzwerkteilnehmern, die gemeinsam über ausreichende Ressourcen zur Implementierung eines Dienstes verfügen und auf die durch das Endgerät zugreifbar ist.

Alternatively, the object is also achieved according to the invention by a network structure with a plurality of network participants, which comprise the following components:

• - at least one service provider,
• component management in which all available services are registered by meta information and which provides a query language via which services or components of such services can be found on the basis of the associated meta information,
• a terminal with which the meta information of the component management can be accessed via the query language in order to access a service, and
• - A group of other network participants who jointly have sufficient resources to implement a service and which can be accessed by the terminal.

This ensures that the object of the invention also is resolved if no single network participant is found who has all the necessary resources for the Service.

Here, too, it is advantageous according to the invention if services and associated interfaces are decoupled by a respective service on the one or more Network participant (s) is implemented by the end device the related one received from component management Interface information is accessible.

It has proven advantageous if the Component management centrally on one network participant is arranged. Alternatively, the component management however, it can also be arranged on several network participants.

By implementing on the network participant (s), not more needed services can be dynamically unloaded save scarce resources.

Possible uses are mainly in distributed Systems with a spontaneous claim to service, especially with Use of the devices mentioned at the beginning with limited Resources, e.g. B. low network bandwidth and low Storage.

The invention thus proposes a central component Administration to create which is a query language implemented with which the components of a requested Service can be found that best meets the needs of the service User. The selection is made using the Service registered meta information. By decoupling of service and interface in several components and their precise description in the collaboration are new scenarios possible such as B. Automatic installation of a part of or all of the service on an additional one Network participant who has the necessary resources available provides. This means that a service is also available on a terminal available, which itself does not have the required Resources. Services that are not required are unloaded again and saved resources.

Further advantages and details of the invention emerge based on the embodiment shown below and in connection with the figures. Each show in Schematic diagram:

Fig. 1 shows a network structure according to the invention with components of administration and decoupling of service and access information,

Fig. 2 is a block diagram of a possible realization of the components of management in the form of a Component repository,

Fig. 3 is a flowchart for setting up a service on the component repository and

FIG. 4 shows a further flowchart to illustrate a possibility for accessing a service according to the invention on the basis of the network structure shown in FIG. 1.

In the illustration of FIG. 1 is a network structure of the invention with components of administration and decoupling of service and access information is shown. Component management is implemented in the form of a component repository CR. A "respository" is basically understood to be a data storage system in which all information about reusable software modules is contained. Repository technology is beneficial because it enables reusability. The stored data are e.g. B. Interface descriptions, functional descriptions, underlying models and concepts (relationships to other software modules, database models and especially models of business processes and objects that are to be mapped in software) as well as the program code of the software modules themselves. The previous use of the software modules can also be in one Repository. In contrast to program libraries, repositories do not only have a standardized program code, but, at a higher level, complete programs, their descriptions and the associated models.

In addition to such a component repository CR, a service Provider SP (service provider), a terminal C (client) as well another network participant P (participating site) intended.

In a first step 1 , the service provider SP registers a service or a component of such a service together with information (descriptors) about the manner in which such a component is executed in the component repository CR. In this way, a large number of such components and services can be registered with the component repository CR.

If a client C now wants to access a certain type of service, a corresponding request is made to the component repository CR in a further step 2 .

The component repository CR then examines whether the client C itself has the necessary resources to implement the requested service. Due to the limitations mentioned at the beginning such as low bandwidth, low CPU capacity, etc., this will usually not be the case. For this reason, in a further step 3, a search is made for a further network subscriber P who has the necessary resources for implementing the service and on which the service is installed. If no such network subscriber is available, it is checked to what extent the service can be split into several parts. These parts are then installed on several network participants, which provide the necessary partial resources.

The access information in the form of interface definitions and proxies are separated from the actual service or its components and are provided to the client 4 by the component repository CR in a step 4 .

This access information gives the client knowledge of the type of service, its configuration, where the service is currently located (network subscriber P) and how it must be accessed (interface). On the basis of this information, the client C then accesses the network subscriber P in step 5 and thus receives access to the desired service. As soon as the service is no longer required, the service is unloaded again by the network subscriber P, so that its resources are again available for other services.

An example application for such a network structure According to the invention is a time service. Assuming the client C needs the exact current time for an application for a time an internal timer is not accurate enough. For this reason, the client C access the time service of a transmitter, the exact one Time signals, e.g. B. from an atomic clock. The client C however, does not have the required functionality and Resources to receive these signals.

For this reason, a corresponding request is sent to the Component management CR, which then the desired time service on one that is as close as possible to the network Machine / network participant with sufficient functionality installed and the client C sufficient Provides access information so that this is now there can access available exact time information.

In order to be able to use complex services spontaneously, they become Services in the form of independent components provided. With complex services it is important Access information such as interfaces and proxies from which decouple actual service implementation. This allows the variable distribution of the service in the network.

On the end device / client C either the complete service installed, if possible, or only Interface information, the service itself becomes spontaneous on one available device installed in the network. Both, the service and the access information are preferably dynamic (Unloadable) to be able to save resources.

To link service and access information must enough meta information, e.g. B. in the form of XML descriptors (see EJB, CORBA Components). In this The service and the access information become meta information described in detail, as well as their linkage and configuration.

A possible structure of the component repository CR is explained in more detail below. This is shown in Fig. 2. Starting from a central component memory CS, which includes a file memory FS and a memory for properties PS, two central functions are offered, the component installation CI and the component management CR. The component memory is preferably based on a database, but in the simplest case can also take the form of a table of contents / directory.

The CI component installation has a central one Installation module I, which on the component memory CS accesses and implementations based on Identification symbols (IDs) of the components.

The component management CR comprises a module / query engine QE, which implements a query language, about the requests of a client C can be edited. This is especially true then significant if the client C has no knowledge of configuration and also has existence of a service. The Query Engine QE also accesses the component memory CS and provides corresponding IDs of suitable service Components.

Component management also includes CR Registration module R. This also accesses the component Storage CS to and additionally to an XML converter XML, which is the interpretation of commands for Data description enabled. The registration module R holds Information about service implementations and related Service descriptions.

In the representation of FIG. 3 is a flow diagram for establishment of a service on the components repository CR is shown. In a step 10, the service provider SP creates a service component SC on the part of the component repository CR. The service components can e.g. B. in the form of a runtime library (so-called Dynamic Link Library DLL), that is, as a software component that is only loaded when necessary. The term DLL thus stands for files with subroutines in the form of already compiled program code, which are only called up and executed by the associated main program at runtime and when required (service request by a client C). Furthermore, the subroutines can be used simultaneously by several different clients C or by several instances of the same program, so that this subroutine is not additionally called up by every main program and brought into the main memory. This reduces the size of the main program and thus the space that it needs in the main memory.

In a subsequent step 11 , a corresponding archive with the program code is generated on the part of the service provider SP and this is registered in step 12 with the component repository CR.

FIG. 4 shows a further flowchart to illustrate a possibility for accessing a service according to the invention on the basis of the network structure shown in FIG. 1 and the registration of a service shown in FIG. 3. The names of the individual steps are as well as possible assigned to those from FIG. 1.

In addition to the modules C, component repository CR, service providers SP and service component SC, which have already been explained above, a name service NS is also provided, which holds central information about the network components available in the network and the addressing. In a step 0, the component management CR is connected to this name service NS. The service is already shown in FIG. 1 and FIG. Registered with the components repository CR 3.

The client C now establishes a connection to this name service NS in step 2 via a so-called bootstrapping protocol. Bootstrapping is a protocol that is typically implemented as UDP "multicast bootstrapping". A station sends a multicast packet to all other network participants and only the network participant that feels addressed responds with a reference to itself (e.g. CORBA Object Reference, see below).

After the connection has been established, the component repository CR is accessed in step 2 'by means of the address information, and in step 2 "a service request is made to the component repository CR in accordance with valid service implementations (cf. step 4 in FIG. 3). is queried.

The client C then uses received IDs from suitable service implementations in step 4 in order to find corresponding DLL objects or other distributed objects on the network subscribers on which services are implemented. In step S, the components found are then loaded to the extent that execution 5 'of the corresponding service components SC is made possible.

Optionally, the service component SC can also contact the service provider SP 5 ″ if the latter has further information that is necessary for the execution of the service.

A possible software implementation of a component repository CR according to the CORBA standard is shown below as an example. CORBA stands for "Common Object Request Broker Architecture". Description of a standardized model for the abstract description of distributed, i.e. active, network-oriented, object-oriented systems and their interaction. CORBA supports the communication between distributed objects, often also called components, and defines a large number of operations that enable the working and interaction of distributed systems and various processes in them. The following implementation is based on such CORBA operators and also uses JINI ™ technology, a connection technology developed by SUN Microsystems, which makes it possible to make devices with different basic technologies available in a common network:

Claims (16)

1. A method for making a service available in a network on a network subscriber who initially has no knowledge of the configuration of this service, characterized in that a decoupling (CR) from the service (SP, SC; 3) and the associated access information ( 4th ) is carried out and, if necessary, the service is implemented on a network subscriber (P or C) or a plurality of network subscribers with the required resources, while the access information ( 4 ) is made available to the network subscriber (C) accessing the service. 2. Procedure for making a service available in one Network according to claim 1, characterized in that Information about the decoupling of service and Access information is kept centrally (CR) in the network. 3. A method for making a service available in a network according to claim 1 or 2 on a terminal connected to this network, characterized in that
the service (SP, SC) is registered ( 1 ) with a component management (CR) of the network and if this service is requested ( 2 ) via the terminal (C)
the component management (CR) service is split and
a service implementation ( 3 ) takes place on another network participant (P) who has the necessary resources while
the access information of the service including the address of this other network participant is made available to the terminal ( 4 ), whereupon
the terminal (C) uses the access information to access the service on the other network participant (P) ( 5 ). 4. A method for making a service available in a network according to claim 1 or 2 on a terminal which is connected to this network, characterized in that
the service (SP, SC) is registered ( 1 ) with a component management (CR) of the network and if this service is requested ( 2 ) via the terminal (C)
the component management (CR) is used to check whether the terminal (C) has all the necessary resources,
if yes, the complete service via the component management (CR) is installed on the terminal (C), or
if not, the service is divided by the component management (CR) and a service implementation ( 3 ) takes place on another network subscriber (P) who has the necessary resources, while the access information of the service including the address of this other network subscriber the terminal (C) is made available ( 4 ), which the terminal (c) accesses with the help of the access information to the service on the other network participant ( 5 ). 5. Procedure for making a service available in one Network according to claim 3 or 4, characterized in that through the component management (CR) a distribution of the Service implementation on several other network participants takes place, especially if no single network participant can be found using all the necessary resources for the service. 6. Procedure for making a service available in one Network according to one of claims 3 to 5, characterized in that services no longer required from the respective end device and the respective network participant on which the service or Parts of a service have been implemented to be unloaded. 7. Procedure for making a service available in one Network according to one of claims 1 to 6, characterized in that Access information that a network participant, in particular a terminal device, Interfaces and proxies of the service includes. 8. Procedure for making a service available in one Network according to one of claims 3 to 7, characterized in that a link and / or a configuration of a service and the associated access information via meta information on the part of the component management (CR) is available, especially via XML descriptors (XML). 9. Procedure for making a service available in one Network according to one of claims 1 to 8, wherein the Accessing network participants also have no knowledge of the existence of service, characterized in that a finding of the service by the inquirer Network participants (C), in particular through the terminal, via a Query language (QE) is made available in the network is, especially centrally via the component management (CR), with a selection about registered with the service Meta information takes place. 10. Method of making a service available in one Network according to claim 9, characterized in that the service is always installed, the associated meta Information best corresponds to an access request. 11. Network structure with a plurality of network participants, which include:
at least one service provider (SP),
component management (CR), in which all available services are registered by means of meta information and which provides a query language (QE) via which services or components of such services can be found using the associated meta information,
a terminal (C) with which the meta information of the component management (CR) can be accessed to access a service via the query language (QE), and
a further network participant (P) who has sufficient resources to implement a service and who can be accessed by the terminal (C). 12. Network structure with a plurality of network participants, which include:
at least one service provider (SP),
component management (CR), in which all available services are registered by means of meta information and which provides a query language (QE) via which services or components of such services can be found using the associated meta information,
a terminal (C) with which the meta information of the component management (CR) can be accessed to access a service via the query language (QE), and
a group of further network participants (P) who jointly have sufficient resources to implement a service and which can be accessed by the terminal (C). 13. Network structure according to claim 11 or 12, wherein services and associated interfaces are decoupled in that a respective service is implemented on the further network participant (s), on which by the terminal (C) via that of the components Administration (CR) received associated interface information ( 4 ) is accessible. 14. Network structure according to one of claims 11 to 13, the component management (CR) centrally on one Network participants is arranged. 15. Network structure according to one of claims 11 to 13, the component management (CR) distributed over several Network participants is arranged. 16. Network structure according to one of claims 11 to 15, being implemented on the network participant (s), not more needed services can be dynamically unloaded.