EP1621031A2

EP1621031A2 - Method for operating a radio communications system

Info

Publication number: EP1621031A2
Application number: EP04723194A
Authority: EP
Inventors: Christina Gessner; Jean-Michel Traynard
Original assignee: Siemens AG; Nokia Siemens Networks GmbH and Co KG
Current assignee: Nokia Solutions and Networks GmbH and Co KG
Priority date: 2003-05-07
Filing date: 2004-03-25
Publication date: 2006-02-01
Also published as: CN1820524A; MXPA05011987A; WO2004100460A3; KR20060009290A; US20080200197A1; JP2006525689A; RU2005138037A; DE10320418B3; WO2004100460A2; BRPI0410241A; AU2004237277A1

Abstract

A data service is provided in which a network-side radio station (BSS) emits data, which can be received by at least one subscriber's station (MS) without a logical connection being set up between the subscriber's station (MS) and the network-side radio station (BSS). Radio parameters for emitting the data are set according to features of subscriber's stations (MS) located within an area assigned to the network-side radio station (BSS). The network-side radio station (BSS) obtains the items of information concerning the subscriber's stations (MS) located within the area and items of information concerning the features of these subscriber's stations (MS), in particular, from a higher-ranking network unit (SGSN).

Description

description

Method for operating a radio communication system

The invention relates to a method for operating a radio communication system, in particular a mobile radio system.

Radio communication systems are used to transmit information, voice or data using electromagnetic waves over a radio interface between a transmitting and a receiving radio station. An example of a radio communication system is the known GSM mobile network, as well as its further development GPRS, the architecture of which, for example, in B. Walke, Mobile Networks and their Protocols, Volume 1, Teubner-Verlag Stuttgart, 1998, pages 139 to 151 and page 295 to 311 is described. A channel formed by a narrow-band frequency range and a time slot is provided for the transmission of a subscriber signal.

For packet data transmission, a radio communication system, for example a GSM mobile radio network with GPRS, comprises a large number of packet data service nodes (serving GPRS support node SGSN) which are networked with one another and which provide access to a fixed data network. For circuit-switched data transmission, the radio communication system comprises mobile switching centers which are networked with one another and which provide access to a fixed network. The packet data service nodes and the mobile switching centers are also connected to base station controllers (BSC). Each base station controller in turn enables a connection to at least one base station (BTS) and manages the radio resources of the connected base stations. Base station and base station control are referred to as base station systems. A base station is a transceiver unit that can establish a message connection to subscriber stations via a radio interface. A distinction is made between two operating modes of a subscriber station: In the idle state, for which the term "idle mode" is common in the professional world, there is no logical connection between the subscriber station and a base station. In the dedicated state, for which the term “dedicated mode” is also used, there is a logical connection between the subscriber station and a base station, in which the subscriber station is assigned a dedicated channel via which a message can be transmitted.

Novel data services have been proposed in which a radio station, for example a base station, transmits data without these data being assigned to a special connection. Rather, the data are sent in the form of a radio transmission and can be received by all subscriber stations located in the radio communication network, in particular within the range of the base station or a defined group of subscriber stations located in the radio communication system. The receiving subscriber stations can be in the idle state, i.e. Idle mode. These services also include the service proposed under the term "Multimedia Broadcast Multicast Services" with the abbreviation "MBMS" for the GERAN standard and the UTRAN standard. For this purpose, reference is made, for example, to the following technical specifications: 3GPP TR 25.992, VI.2.0 (2003-01) "Multimedia Broadcast Multicast Service (MBMS); UTRAN / GERAN Requirements", TR 23.846, V6.1.0 (2002-12) "MBMS ; Architecture and functional description (Release 6) ", and TS 22.146, V6.1.0 (2002-09)" MBMS; Stage 1 (Release 6) ".

Potential subscribers to such data services can be registered in the radio communication system. They are then provided with an identifier and can be assigned to certain signaling channels as a group, for example as a paging group Paging channel. These services are billed through registration.

In these data services, the data are only transmitted from a network radio station. Since no dedicated connection is established between potential subscribers to the data service and the network radio station, the network radio station generally does not have any information about the features of the subscriber stations participating in the data service. The transmission of the data must therefore be configured by the network radio station so that reception is possible for all subscriber stations. The configuration must therefore be based on the minimum performance features of subscriber stations that can be operated in the radio communication system. Features of higher-quality subscriber stations that go beyond the minimum features can only be taken into account in the context of a dedicated point-to-point connection, which should not be used for such data services because of the required radio resources.

The invention is based on the problem of specifying a method for operating a radio communication system in which, for data services in which a network-based radio station transmits data without these data being associated with a specific connection, features of subscriber stations which go beyond a minimal configuration can be taken into account.

This problem is solved by a method and an arrangement according to the independent claims. Further refinements of the invention result from the dependent patent claims.

A data service is provided in which a network-based radio station transmits data that can be received by at least one subscriber station without a logical see connection between the subscriber station and the network radio station is set up. The network-side radio station is designed, for example, as a base station system (BSS - Base Station System). For example, short video clips are sent out via the data service. As a rule, the data service is received by more than one subscriber station. The data is sent in the form of a broadcast. The radio parameters for the transmission of the data are set as a function of performance features of subscriber stations that are located in an area assigned to the network-side radio station.

The method thus takes into account which features support subscriber stations that are actually potential subscribers to the data service because they are in the area assigned to the network radio station. Subscriber stations that are outside this area and that may support fewer features are not taken into account when setting the radio parameters. The transmission of the data can thus take place with the radio parameters that can be supported by the subscriber station in the area with the worst or the fewest performance features. The performance features relate, for example, to different modulation and coding schemes or the property of subscriber stations to be able to receive data over more than one time slot, for which the term multi-slot capability is common in the professional world.

An advantage of the proposed method is that subscriber stations with demanding performance features can also use these performance features as far as possible. Information that the base station system needs for this is provided within the radio communication system without the signaling traffic on the air interface between the subscriber station and the base station system being burdened thereby. In a network unit which is superior to the network radio station, there is preferably information about the subscriber stations located in the area assigned to the network radio station and information about the performance features of these subscriber stations. The higher-level network unit then transmits a message to the network-side radio station, on the basis of which the network-side radio station sets the radio parameters for the transmission of the data.

For example, the higher-level network unit corresponds to a packet data switching unit, as is provided under the term SGSN in a radio communication system constructed according to the GERAN standard or in a UTRAN standard. Location data, so-called routing information, is collected in the packet data switching unit for all subscriber stations located in a location area for which the term routing area is used. This routing information can be used to determine the subscriber stations located in the area assigned to the network radio station. In this case it is advantageous if the area assigned to the network radio station corresponds to the routing area. However, the area assigned to the network-side radio station can also affect only a part of the routing area, for example a radio cell that is served by the network-side radio station.

This message is preferably transmitted before radio resources for the data service are allocated in the network radio station. This can be done, for example, with the MBMS Radio Access Bearer Setup, which is provided in the UTRAN standard, or with the PFC (Packet flow context) setup, which is provided in the GERAN standard.

According to one embodiment of the invention, the message that is transmitted from the higher-level network unit to the network-side radio station contains the information about the performance features of all subscriber stations that are in the Stop area. In this case, this information is evaluated in the network-side radio station and it is determined which is a minimum combination of features that is supported by all subscriber stations located in the area. This minimal combination of features is then used as a basis when setting the radio parameters for the transmission of the data service.

According to another embodiment of the invention, a minimum combination of features is determined in the higher-level network unit and is supported by all subscriber stations located in the area. In this case, the message to the network-side radio station only contains information about the minimum combination of features. This procedure has the advantage that less data is transmitted between the higher-level network unit and the network-side radio station and that the processor of the network-side radio station is not burdened with this evaluation.

It is within the scope of the invention that the higher-level network unit has information about the registration of the respective subscriber station for participation in the data service and the higher-level network unit receives the information about the performance features of the subscriber station when the subscriber station is registered.

Alternatively, in the event of a change of location, the subscriber station sends a message to the higher-level network unit, which contains the information about the features of the subscriber station. This can be done, for example, as part of the messages that are already provided for exchanging the routing information in accordance with the GERAN standard or UTRAN standard. The radio parameters for the transmission of the data service are preferably changed when the number of subscriber stations located in the area changes. If a subscriber station thus leaves the area, a check is carried out to determine whether the minimum combination of features that was used when setting the radio parameters still corresponds to the current minimum combination of features of the subscriber stations remaining in the area. For example, if the subscriber station with the lowest combination of features has left the area, the radio parameters are reset in accordance with the current minimum combination of features, which is supported by the remaining subscriber stations. If, on the other hand, a subscriber station is added, it is checked whether this subscriber station supports all the features that are contained in the minimum combination of features that was used as the basis for the current setting of the radio parameters. If the newly added subscriber station supports fewer features than are contained in the minimal combination of features used, an updated combination of features is determined which is used as the basis for re-setting the radio parameters for the transmission of the data service. This ensures that the newly added subscriber station can also receive the data service.

If the information about the subscriber stations located in the area and their performance features is managed in the higher-level network unit, it is advantageous to notify the network-side radio station of this information regularly or whenever there is a change.

The invention is explained in more detail below on the basis of an exemplary embodiment which is illustrated in the figure.

The figure shows a message exchange when setting up a transmission of a data service. One or more subscriber stations MS, a base station system BSS, which comprises a base station controller BSC and a base station BTS, and a packet data switching unit SGSN are involved in the data service, for example an MBMS. First, the subscriber station MS is registered 1 with the packet data switching unit SGSN. Registration 1 includes, for example, the scope of the data to be received as part of the data service, information about the subscriber station that is necessary for billing the data service and information about performance features that the subscriber station MS supports. Registration 1 is generally carried out independently of a current broadcast as part of the data service. As a rule, registration 1 takes place between a plurality of subscriber stations MS and the packet data switching unit SGSN.

At the beginning of the transmission of data as part of the data service, an announcement 2 is made, with which the packet data switching unit SGSN uses a broadcast channel to indicate the intended transmission. The announcement 2 can be received by all subscriber stations MS located in the transmission range of the SGSN, so that potential subscribers can set up to receive the data.

The packet data service unit SGSN sends a message 3 to the base station system BSS which contains information about the subscriber stations MS located in an area assigned to the base station system BSS and information about the performance features of these subscriber stations MS. The message 3 contains, for example, the minimum combination of features that is supported by all subscriber stations MS located in the area.

The packet data switching unit SGSN takes the information about which subscribers MS are in the area routing information sent regularly in accordance with the GERAN or UTRAN standard.

On the basis of the minimum combination of performance features taken from message 3, the base station controller BSC within the base station system BSS sets radio parameters which are used for a subsequent transmission 4 of the data from the base station system BSS to potentially participating subscriber stations MS.

If a subscriber station MS leaves the area assigned to the base station system BSS, the packet data switching unit SGSN receives information about this change of location. An updated minimum combination of features is then determined in the packet data switching unit SGSN and transmitted to the base station system BSS via a further message. If the updated minimum combination of performance features and the previously used minimum combination of performance features differ, the base station controller BSC within the base station system BSS re-sets the radio parameters for the further transmission of the data service.

Claims

claims

1. A method for operating a radio communication system, in which a data service is provided, in which a network radio station transmits data that can be received by at least one subscriber station without a logical connection between the subscriber station and the network radio station being established, and in which Radio parameters for the transmission of the data can be set as a function of performance features of subscriber stations that are located in an area assigned to the network-side radio station.

2. The method of claim 1, in which in a network unit superordinate to the network radio station, there is information about the subscriber stations located in the area assigned to the network radio station and information about the performance characteristics of these subscriber stations, in which the network unit transmits a message to the network radio station , on the basis of which the network radio station sets the radio parameters for the transmission of the data.

3. The method of claim 2, wherein the message contains information about the features of the subscriber stations that are in the area.

4. The method according to claim 2, in which in the network unit the minimum combination of features is determined, which is supported by the subscriber stations located in the area, in which the message contains information about the minimum combination of features.

5. The method according to any one of claims 2 to 4, in which there is information in the network unit about the registration of the subscriber station for participation in the data service, in which the network unit receives the information about the features of the subscriber station when the subscriber station is registered.

6. The method according to any one of claims 2 to 4, in which the subscriber station in the event of a change of location sends a message to the higher-level network unit, which contains the information about the features of the subscriber station.

7. The method according to any one of claims 1 to 6, in which the radio parameters for the transmission of the data are changed when the number of subscriber stations located in the area changes.

8. Arrangement for operating a radio communication system, with a network-side radio station for transmitting data from a data service to at least one subscriber station located in an area assigned to the network-side radio station with radio parameters that are set as a function of performance features of subscriber stations located in the area, with between no logical connection is set up for the at least one subscriber station and the network radio station.

9. Arrangement according to claim 8, consisting of a base station controller (BSC) and at least one base station (BS).