Method for transmitting at least one group message, associated radio communications network, subsystem and mobile radio device

Translation of description of equivalent WO 03094552 A1

description

A method for transmitting at least one group message, associated wireless communication network subsystem and mobile radio device

The invention is based on the object of disclosing a way as at least one group message can be transmitted to one or more subscriber devices at least one group in an effective manner as possible in a radio communication network.

This object is solved with the features of claim 1.

The invention also relates to a radio communication network according to claim 6, an associated subsystem according to claim 7 and a radio communication device of claim 8.

The invention and its developments are below other hand drawings explained.

Show it:

Figure 1 is a schematic representation of network elements and their interconnection in

UTRAN subsystem of UMTS (Universal Mobile Telecom System unication),

Figures 2, 3 are each a schematic representation of a MBMS context in the UTRAN subsystem of Figure 1, which is managed by at least one higher-level radio network control unit of this subsystem A process according to the invention, and Figures 4 to 6 are each a schematic illustration for implementing the method according to the invention, the signaling on the air interface between the respective subscriber device and the superordinate radio network controller in the UTRAN subsystem of UMTS according to FIG. 1

Elements having the same function and mode of operation are provided in Figures 1 to 6 with the same reference characters.

For many, offered in modern mobile radio systems, services and applications are news not only to one but to two or more mobile subscribers at least one predetermined group is transmitted. Examples of such services and applications are news groups, video conferencing, video on demand, distributed applications, etc.

When sending messages to the different

Participants it is possible to send each recipient separately a copy of the data. However, this technique is simple to implement, for large groups unsuitable. Since the same message via N (N = number of recipients of the message) individual connections (unicast connections) is transferred and is thereby sent repeatedly over common connection paths, this method requires a very high bandwidth.

A better possibility is the so-called multicast transmission. Here, the various participants, where the same message is to be transmitted, combined to form a group (multicast group) zusa and assigned to this one address (multicast address). The data to be transferred will then be sent only once to this multicast address. About common connection paths from the sender to the recipients, the multicast (= MC) message is sent, ideally only once. For the transmitter, it is not necessary lent to know where and how many recipients are concealed behind the particular multicast address. To news of a certain multicast groups receive, uss a participant enroll for this multicast group.

When broadcast messages are sent to a group of subscribers within a regional area. The area in which the broadcast messages are sent, is characterized as a so-called broadcast Area (broadcast area) described. The size of the broadcast area is determined by the network operator. About common connection paths, the message is thereby ideally like, also sent in multicast only once. A disadvantage here, however, that all participants within the broadcast area will have the opportunity to read broadcast messages, even if they are not entitled. Only certain messages to read and discard other or to filter, participants may make appropriate adjustments to their terminals. An explicit enrollment to a broadcast service is not required.

In the specifications of the third generation of mobile communications systems, in particular for the UMTS mobile communication system (universal mobile telecommunication), the so-called. Multimedia Broadcast and Multicast Service (MBMS) (service = service) is described. This enables the transmission of multimedia data over multicast and broadcast.

The following are only the network elements of the UMTS access network, the so-called UMTS Terrestrial Radio Access Network's (UTRAN), considered in more detail as a subsystem of UMTS radio communication network. In the figure 1, the following components and their connection are of the network elements to each other provided by way of example illustrated schematically: NodeB:

A NodeB (base station), here the two base stations No- DEBL, NodeB2, is a network component that is responsible for the supply of one or more radio cells via at least one air interface. With the help of the respective NodeB communication between the landline portion or superordinate radio network part of the UMTS Mobilfunksyste s and the subscriber devices takes place, in particular mobile phones, which are located in the radio cell surrounding the base station through at least an air interface.

Radio Network Controller (abbreviated RNC) = radio network controller:

An RNC controls the resources of the air interface and provides and controls one or more base stations (NodeB 's).

User eguipment (UE) = subscriber device;

The UE (short for User Equipment) is in particular a mobile terminal, which is connected via the air interface with the UTRAN.

1 shows the two base stations NodeBl, NodeB2 and their associated radio cells CEI, CE2 are controlled by the parent radio network controller RNCl exemplary. The base station NodeBl is a hard line LI1, base station NodeB2 connected via a fixed line LI2 with the commonly assigned radio network controller RNCl. In the radio cell of the base station CEI NodeBl adhere to the three participating Devices UEL, UE2, UE3, who are enrolled and registered for the group GRl. They communicate via the air interface with the base station LSI NodeBl and the control unit coupled thereto RNCl.

In the MBMS specifications is determined that the data of MBMS services to be sent only in the radio cells in which actually subscriber devices or UEs are wishing to receive this service. To realize this, the UTRAN requires, in particular the RNC, knowledge or information about whether participants or UEs want to receive a specific MBMS service to th, in one of the radio cells for which it is responsible. This information has not UTRAN, and in particular the RNC, according to the prior art. It also specified that a subscriber device (= UE) MBMS can receive the so-called idle mode 'is. In this state (idle mode), the UTRAN has no knowledge of the UE, ie it does not even know that it ever is in one of its radio cells.

UTRAN can not make a decision fertil therefore according to the prior art, whether MBMS data to be transmitted in radio cells, even if there are UEs that want to receive the service.

For this embodiment, a radio cell (Zeil- ID = N; cell-ID = cell-identity) is such as CEl considered, which is supplied for example by a NodeB RNCl such as NOdeBl and an RNC. Furthermore, an MBMS service (MBMS group ID = XYZ) is considered.

It is now shown as the first, as a MBMS context in the UTRAN, and in particular in the RNC, can be formed and inserted in an advantageous manner. This is illustrated by two examples.

Example 1:

It is located in the radio cell CEI with the cell ID, N = 1 '1 (a) participants with the UE Id, A' [this Informationsele- is ent optional] which receive the MBMS service with MBMS service ID, XYZ ' would like. In Figure 2 this MBMS context is exemplified. Example 2:

It be assumed that there are now in the radio cell CEI with the cell ID, N = 1 '3 UEs UEL, UE2, UE3 with the UE Ids, A', B 'and C [this information element is optional!], wishing to receive the MBMS service with MBMS service ID, XYZ '. In Figure 3, this MBMS context is exemplified.

If there are no participants in the considered radio cell CEI are wishing to receive the MBMS service, no MBMS context is managed and maintained in the RNC for this MBMS service in this radio cell.

It will now be shown as the second, as an advantageous signaling between UE and RNC looks constructed on the basis of which the MBMS context in the RNC, adapted and / or is degraded.

For this, it is assumed that no UE is in the radio cell look like CEI, which wants to receive the MBMS service, XYZ '. It is therefore maintained service and the radio cell not MBMS context in the RNC for this MBMS. It is thereby further angenommen- that a UE such as UEL with the UE Id, A 'in the radio cell in CEI with the cell ID, N = 1' will change and already for the MBMS service with MBMS service ID., XYZ 'is subscribed. On the basis of measurements, the UE = UE1 now detects that it is located in a new cell. According to the invention, the subscriber device UEL now sends an information signal ISL ( "MBMS notification *) to the higher radio network controller (= RNC) RNCl. This MBMS notification contains the MBMS group ID to which the UE UEL is enrolled (eg the TMGI (^{= Λ}temporary mobile group identifier^Λ = Acronym for "temporary group identifier *) and optional information about his identity (UE ID). The RNC, here RNCl, now establishes the MBMS context of the invention. This looks in this case as in Example 1 above. The same "MBMS notification * ISL sends the subscriber device (= UE) and the RNC when the UE is already in the radio cell in question and for subscribing new to the MBMS service, that is inscribed and thus in each group" on line^NλIe actively connected. This signaling scenario is illustrated in FIG. 4

Sending the information signal ISL ( "MBMS notification *) is now performed by each UE to the parent radio network control unit, here RNCl that changes in the radio cell in question and is enrolled to the MBMS service, and for each UE that is already in the radio cell in is and subscribes to the MBMS service. The MBMS context in the RNC for this radio cell and this MBMS service is then adjusted accordingly.

If necessary, can such instruction or information elements such as MBMS group ID and UE-Id optionally be integrated into existing prior art messages and sent to the relevant RNC.

Should a UE the radio cell in question, so it sends expediently in the new radio cell again an MBMS notification such as ISL to the responsible RNC such as RNCl grooming then a corresponding MBMS context for the new radio cell and the MBMS service managed or. In addition or independently thereof received this, the

Radio cells changing UE expediently in the old radio cell, ie in the radio cell, which just leaves the UE, another Infor ationssignal such as IS2 (, MBMS leave '(eng. Leave = leave)), ie, an indication or a message, to the competent RNC so that it knows that now a UE that wants to receive the MBMS service, is less in the radio cell in question. The "MBMS leave message¹* Expediently contains the information elements MBMS group ID (eg, the TMGI) and optionally the UE ID of the subscriber device (= UE) that the "MBMS leave message * sends. The RNC will adjust appropriately the MBMS context for that radio cell and this MBMS service accordingly. This signaling scenario is illustrated in FIG. 5 There is the information or indication signal of "MBMS leave message" sent by the subscriber unit UEL for competent, parent radio network controller RNCl leaving the radio cell CEI denoted by IS2.

This "MBMS leave message * IS2 is expediently also sent if the UE remains in the radio cell in question and touting of the MBMS service. This signaling scenario is illustrated in FIG. 6

If necessary, can the information elements such as MBMS group ID and UE-Id optionally be integrated into existing already in the prior art messages and sent to the RNC.

Has the last UE wants to receive the data of the respective MBMS services, leave the respective radio cell and is advertised by each MBMS service and a corresponding "MBMS leave message * sent to the RNC, this builds the MBMS context for that radio cell and this MBMS service from or deletes it.

In general terms therefore an MBMS context in UTRAN is introduced advantageously describing per radio cell, whether and how many participants have registered (eg described by a MBMS group identity) to an MBMS group. The MBMS context in the UTRAN, and in particular the RNC maintained, managed and modified. Through the MBMS context is achieved that the UTRAN has knowledge of whether and how many UEs belonging to a particular MBMS Service are enrolled, are located in the radio cells that are managed by it. Based on this information, the UTRAN subsystem, in particular the RNC, to make the decision whether MBMS data is transmitted in a radio cell or not. Furthermore, UTRAN may make the decision based on the MBMS context, if necessary, whether in a small number of participants point-to-point transmission (each participant receives its data assigned him compounds) or point-to-multipoint transmission (the participants he - keep their data through a common connection) should be carried out.

Optionally, the MBMS context in the UTRAN in addition, the information which UEs (in particular which UE identities) are subject to an MBMS group. This information may, for example. Be used to when the UTRAN in a small number of recipients, the decision is made, to-point transmissions to use point for the transmission of MBMS data. The UE identities are then used for the construction of user-specific point-to-point connections.

The MBMS service-specific and cell-specific radio MBMS context is preferably constructed in each jurisdiction, the parent radio network control unit, when the first UE in the cell wants to receive an MBMS service. The MBMS context is there modified in the control unit and adjusted to reflect new user equipments (UEs) in the radio cell you want to receive the same MBMS service or if UEs want to leave the radio cell or no longer receive the service. The MBMS context is expediently terminated, if there is no more UE is in the cell that wants to receive the specific MBMS service.

Once a new UE is in a cell, it sends a notification, hereinafter, MBMS notificati- on denotes' to the UTRAN, in particular to the RNC. These MBMS notification preferably contains at least the MBMS group identity (eg, the TMGI [Temporary Mobile Group Identity]) identify or multiple identities (if UE is subscribed to a number MBMS services), the unambiguous one MBMS service tig. Optionally, the "MBMS notification" additionally contain the UE identity of the UE, which has sent the message.

The respective UE sends the "MBMS notification * to the competent, superior radio network controller (RNC), in particular when:

- Is located in a radio cell and subscribes to a new MBMS service, and / or

- Moves from one radio cell to a new cell. UE recognizes, for example. The basis of measurements that it is in a new radio cell and automatically sends an MBMS notification to the UTRAN.

This UTRAN may adapt the MBMS context when UEs leave the radio cell, turn off, and / or to write out of the MBMS service, transmits the respective UE in these cases expediently a message to the UTRAN so that the UTRAN knows that now a UE less located in this radio cell. When leaving the 'old' radio cell is thus a message in the 'old' cell sent to the local base station to the associated control unit that there is a UE is now less available, and a message in the 'new' cell at the local base station with its associated control unit that there is a UE longer exists now that wants to receive a specific MBMS service. This message is referred to as "MBMS leave message" within the scope of the invention. This "MBMS leave message * preferably contains the MBMS group identity (TMGI as the [Temporary Mobile Group Identity]) or optionally a plurality of identities (if the respective UE to several is MBMS services inscribed) that identify an MBMS service clearly. Optionally, the "MBMS leave message * in addition, the UE identity of the UE, which has sent the message contained.

In the invention, the following abbreviations and terms have been used which are standard introduced in particular in mobile radio technology as acronyms and possibly definitions or common:

Id identity (eg UE Id describes UE uniquely)

MBMS Multimedia Broadcast / Multicast Service

NodeB base station in the UMTS

RNC Radio Network Controller (radio network controller)

TMGI Temporary Mobile Group Id (identifies the MBMS group clearly)

UE User Equipment (Mobilf nkgerät the UMTS network)

UMTS Universal Mobile Telecommunication System

UTRAN UMTS Terrestrial Radio Access Network

In this way, a subsystem for a radio communication network for the transmission of at least one group message to at least one receiving subscriber unit is provided. This subsystem of the radio communication network is formed by at least one user terminal and at least one parent radio network control unit, which are designed for carrying out the process.