Transmitting multicast messages, especially in mobile radio network, involves originating subscriber unit sending message via subordinate, superior network control units to multicast center

The invention relates to methods, devices and software programs to send a multicast message to a multicast group.

In modern mobile radio systems such. As to the UMTS (Universal Mobile Communication System), GPRS (General Packet Radio Service), EDGE (Enhanced Data Rates for GSM Environment) it is desirable to messages not only to an individual, but to two or to transfer more mobile subscribers. Examples of such services and applications are called. Neves-Groups, video conferencing, video on demand, distributed applications, etc ..

To date, several methods for transmitting messages to subscribers or members of a group are already known.

document <patcit><text>WO 99/63773 A1</text></patcit> discloses a distribution device (Packet Handler), distributes the messages to multiple users of a group, for which purpose each individual links between the members of a group and the distribution device (Packet Handler) are furnished.

document <patcit><text>WO 01/20939 A1</text></patcit> discloses a so-called point-to-multipoint service center, which also distributes messages to multiple users of a group, this individual connections to the subscribers of the group are also set up.

From document <patcit><text>WO 01/45335 A1</text></patcit> it is known to realize a group call by using a so-called gateway server, wherein the group call is implemented using individual connections to the gateway server.

From document <patcit><text>WO 01/45310 A1</text></patcit> is a network known by each network node is a potential multicast center, can be made via the transmission of multicast messages.

From the non-prepublished document <patcit><text>DE 101 32 795 A1</text></patcit> A method is known, accordingly to participants of a group using a multicast Centers messages can be sent via multicast method. Whether the source of the message in this case even a member of the group is, or may be, remains open.

When sending messages to the various participants, it is advantageous, the various NEN subscriber devices, where the same message is to be transmitted, combined to form a group (= multicast group) and this assigned a common identification address. This prevents the same message via N (N = number of recipients of the message) individual connections to transmit (unicast connections) and to send several times over common connection paths. Using the multicast method needs the multicast message (= message group) are sent only once to the multicast address (= group address).

To facilitate understanding of the problem by way of example on the components of the packet-switched network architecture (packet switched domain) of a UMTS mobile network are addressed below. Currently, the data transmission in the packet switched transmission is specified, only the connection between a mobile station or a subscriber device and an external network for the UMTS standard, which is described in more detail below.

According to the <figref idrefs="S23">1</figref> is in a mobile radio system according to the UMTS standard, a user equipment UE (User Equipment) - in <figref idrefs="S23">1</figref> several UEs, namely UE1, UE2, UE 4 and shown UE5 - connected via an air interface with at least one base station NB (Node B), which in turn via a phantom shown landline connection with a higher-level network unit, the radio network controller RNC (Radio Network Controller) connected is. Several base stations may be connected to a RNC. In the<figref idrefs="S23">1</figref> are z. B. two base stations connected to the RNC 1 and RNC2. An RNC has the task to manage the resources within the cell and to check the connection between user equipment and base station and base station and RNC. An RNC and one or more base stations form a radio subsystem (Radio Network Subsystem RNS), wherein a number of so-called RNSs the. UTRAN (UMTS Terrestrial Radio Access Network) form.

Each RNC is referred via another landline connection at a higher network entity in UMTS as SGSN (Serving GPRS Support Node), respectively. It can be connected to a SGSN several RNCs. In the<figref idrefs="S23">1</figref> the RNC1, RNC2 and RNC3 are connected to the SGSN 1. A SGSN has the task of establishing the connection between a user terminal and an external packet data network EN (External Network) and configure. Access to the external packet data network EN is implemented by a further network unit, the GGSN (Gateway GPRS Support Node). Multiple SGSNs can thereby be connected to a GGSN. In the<figref idrefs="S23">1</figref> are SGSN 1, SGSN2 and SGSN3 connected to a GGSN.

The signaling to establish a connection between a UE and an external network EN is in <figref idrefs="S24">2</figref> shown. Want a user equipment UE1 to connect to an external packet data network EN build, so is first starting from the user equipment a signaling connection N1 "RRC Connection Setup" (= "RRC connection setup", said RRC Radio Resource Control) established between UE 1 and RNC2, s.<figref idrefs="S23">1</figref>, The user equipment UE1 now sends a message N2 "Service Request" (= "Service Request") via RNC2 to SGSN 1. This message is first sent to RNC2, which forwards the message in another message "Initial UE Message" (= "Initialize UE Message") to the SGSN 1. With the message "Initial UE Message" a signaling connection between RNC and SGSN is simultaneously constructed, which is uniquely assigned to the user equipment UE1.

Now that a signaling connection between user equipment UE1 and the network unit has been built SGSN 1 sends the user equipment UE1 a message N3 "Activate PDP Context Activation" (= "Activate PDP Context Activation", said PDP = Packet Data Protocol = Packet Data Protocol) to the SGSN 1 , with the SGSN1 is prompted to establish a data connection between the UE 1 and the external network EN. This message contains the desired quality of services (QoS = Quality of Service), so the settings for the connection between UE 1 and the external network EN. In addition, an identification of the external network EN and an identification of the desired services are included.

SGSN 1 stores the received parameters for the connection in the form of a connection parameter set, this is referred to in UMTS as PDP context and then sends a message N4 "RAB Assignment Request" (= "RAB Assignment Request", said RAB = Radio Access Bearer) to RNC2 , A PDP context is always exactly one UE assigned, ie the PDP context also includes an identification of the corresponding UE. In this message, the RNC2 the settings to establish the connection between SGSN 1 and RNC2 are notified. In addition, the RNC2 is communicated to an identification of the link between SGSN 1 and RNC2 in direction of RNC2 to SGSN 1. This identification is then added later in the data transmission from the RNC2 to data packets that it has received from the user terminal UE1, before forwarding the data packet to the SGSN1. SGSN 1 can thus be assigned to a PDP context, ie a compound based on this identification the message.

After receiving the message N4 "RAB Assignment Request" RNC2 stores the parameters of the connection (PDP context) and builds in turn using message N5 "RB Setup" (= "RB-building") and N6 "RB Setup Complete" (= " RB-construction completed ") a data connection between the user equipment UE1 and the radio network controller RNC2 on. In the UMTS standard, this connection with radio bearer (RB) is called. After establishment of the radio bearer of RNC2 a message N7 "RAB Assignment Response" sends (= "RAB Assignment Response") back to the SGSN 1, which confirms the structure of the connection between UE 1 and RNC2, and the connection between RNC2 and SGSN 1. The message N7 "RAB Assignment Response" provides a corresponding identification of the PDP context and an identification for the connection between RNC2 and SGSN 1 (TEID = Tunnel Endpoint Identifier = Tunnelendpunktidentifizierer) towards SGSN 1 to RNC2, which later added the SGSN 1 in packet data transfer packet data is that received from a GGSN for transmission to the subscriber device UE1 the SGSN 1. On hand of the TEID of the RNC2 then know for which PDP context the message is intended and may forward them to the corresponding radio bearer to the UE1.

After receiving the message N7 "RAB Assignment Response" message the SGSN1 N8 a "Create PDP Context" sends (= "Create PDP Context") to the GGSN, which forms the access to the external network. Within this message again the parameters for the connection (PDP context), an identification of the PDP context and an identification for the connection between the SGSN1 and the GGSN GGSN in the direction of to SGSN1 are included. The identification for the connection between the SGSN1 and GGSN (TEID) is later added to the packet data transmission from the GGSN to the packet data that are sent for the PDP context of the user equipment UE1 from the GGSN to the SGSN 1. This allows the SGSN 1 to assign the packet data corresponding to the PDP context.

The GGSN then sends a message N9 "Create PDP Context Response" (= "Create PDP Context Response") to the SGSN1 back, it is confirmed by means of which the connection between GGSN and SGSN1. The message in turn contains an identification of the PDP context for which the connection has been established, and an identification of the compound (TEID) itself, which will be added later by the SGSN 1 in packet data transmission from the UE 1 in the external network EN the packet data and which allows the GGSN1 , the packet data assigned to a particular PDP context.

Now that the entire connection is established between UE 1 and GGSN1, sends the SGSN 1 a confirmation message N10 "Activate PDP Context Accept" (= "Activate PDP Context Accept") This connection setup to the user equipment UE1.

When the UE1 now transmits packet data over the established this bearer for the PDP context Radio be sent to the RNC2. The RNC2 detects due to the radio bearer, via the packet data has been received, to which PDP context includes the packet data and to which connection between RNC2 and SGSN 1 used for the transmission of data. For this purpose, the RNC2 adds the corresponding TEID, which identifies the connection between the RNC2 and SGSN1 in the direction of RNC 1 to SGSN 1, the data packets and sends them to the SGSN1. The SGSN 1 detects based on the TEID of the PDP context, which includes the data packets, and knows which connection is associated with the PDP context between SGSN1 and GGSN. The SGSN1 then adds the TEID of the connection between the SGSN1 and the GGSN GGSN in the direction of SGSN1 according to the data packet and sends it to the GGSN. The GGSN recognizes from the TEID to which PDP context includes the packet data and forwards them to the appropriate service and the corresponding external packet data network EN further.

It is an object of the present invention, the functionality on the dispatch and reception of multicast messages in a cellular network, especially one of the so-called. Generartion third, to expand.

This object is achieved in the method according to the invention by the features of claim 1. Furthermore, this object is achieved in the devices of the invention or the software programs according to the invention by the features of claims 12 and 13 and 18 respectively.

The advantages of the invention are, in particular, that by means of the invention, a simple sending of multicast messages from a mobile station or a user equipment (UE) is allowed to a network entity called a multicast center, then the distribution of the multicast message to the participants the multicast group initiates.

Advantageously, the inventively used multicast Center is logically connected to one or more GGSNs, the multicast Center can also be located on an external network. Alternatively, the functionality of the multicast Centers is constitutes in one or in all GGSNs. Again, an appropriate accommodation in one or more external networks is possible. In the event that the multicast center functionality is not present in all GGSNs may preferably without the GGSNs multicast center functionality logically be associated with one or more GGSNs, which contain a multicast center functionality.

According to the multicast Center - also known as' the MCC - designed so that it can receive multicast messages from users within the mobile network.

Since the data traffic of different user terminals, the message will be sent to a particular multicast group, can not be predicted, it is hardly possible to transfer characteristics for a common connection for. B. between RNC and SGSN for multiple user devices which a multicast group are to be determined. Preference is therefore given for the transmission of multicast messages to a multicast Center used towards the user equipment no common connections, but it is in each case a connection is established between UE and multicast Center per multicast group for each user equipment.

To enable the transmission of a user to a multicast Center, the functionality of the network units GGSN, SGSN and RNC is expediently extended: The GGSN is preferably extended by at least one of the following functionalities: <ul list-style="bullet"><li>- The GGSN preferably recognizes that this to be a multicast message in a message sent from a subscriber unit message received from an SGSN, the GGSN, which is forwarded to the multicast Center. Preferably, this can be done on the connection between GGSN and multicast Center Use the illustration of the connection between SGSN and GGSN, which was made when the connection between US and MCC.</li><li>- Preference assigns the GGSN the connection in the direction from SGSN to GGSN only a PDP context. Preferably, for this purpose each have a connection identifier TEID is assigned to a PDP context for connecting SGSN to GGSN. Note: For the opposite direction, the GGSN assigns preferably the connection between GGSN and SGSN in the direction of the GGSN to SGSN multiple PDP contexts, preferably by means of a connection identifier TEID for this PDP contexts.</li><li>- Preferably, the GGSN detects when a connection, that there is a connection for the transmission of multicast messages.</li></ul>

The SGSN is preferably extended by at least one of the following functions: <ul list-style="bullet"><li>- Preferably, the SGSN is able to assign the connection in the direction of RNC by SGSN only a PDP context. It is therefore proposed, for connecting RNC to SGSN a PDP context in each case one connection identifier, particularly the TEID assigned. Note: The connection between SGSN and RNC in the direction of SGSN to RNC is preferably associated with multiple PDP contexts.</li><li>- Preferably, the SGSN on the ability to associate a connection coming from the GGSN multiple PDP contexts, but in each case assigned exactly the same PDP contexts for a GGSN outbound connection. This is preferably realized in that several PDP contexts of the incoming connection from the GGSN, a connection identifier, particularly the TEID, and for the GGSN to the same PDP contexts outgoing connections to in each case one is assigned TEID.</li><li>- Preferably, the SGSN detects when a connection, that there is a connection for the transmission of multicast messages.</li><li>- Preferably initiated the SGSN independently to connect to all UEs of the multicast group, managed by the SGSN.</li></ul>

The RNC is preferably extended by at least one of the following functions: <ul list-style="bullet"><li>- Preferably, however, the RNC's ability to assign a connection coming from the SGSN several PDP contexts, the same PDP contexts exactly one outgoing connection to SGSN assigned. This is preferably realized in that several PDP contexts from the SGSN of the incoming connection is a connection identifier, particularly the TEID, and for the outgoing connections to the same SGSN PDP contexts each a TEID is assigned.</li></ul>

Advantageous developments of the invention are characterized by the features of the subclaims.

The invention and its developments are explained in more detail using the drawing. The invention is here described by way of example with reference to the modifications of the known UMTS network and the corresponding protocols. But the invention is of course also suitable for mobile networks.

Show it:

<figref idrefs="S23">1</figref> a schematic representation of the basic architecture of a UMTS Mobi radio system according to the prior art;

<figref idrefs="S24">2</figref> a schematic illustration of the sequence of a connection setup for a known data packet transmission from a user equipment in an external network according to <figref idrefs="S23">1</figref> according to the prior art;

<figref idrefs="S25">3</figref> a schematic representation of the basic architecture of the mobile radio system using a multicast center according to this invention, and

<figref idrefs="S26">4</figref> a schematic illustration of the sequence of a connection setup for the sending of a multicast message by a single user terminal according to the inventive method.

<figref idrefs="S25">3</figref> shows the network according to an embodiment of the present invention. It is further believed that UE4 a multicast message, called MCN1, wants to send to participants of a multicast group A, which includes the well believed to UE5 and UE1. The difference compared with the known construction according to the<figref idrefs="S23">1</figref> consists especially in the additionally provided Multicast center MCC connected according to this embodiment with the GGSN. The differences in the protocols and the messages sent is in reference to the<figref idrefs="S26">4</figref> explained in more detail.

While the focus of the invention on the sending of a multicast message from a subscriber device to a multicast Center for the purpose of forwarding the message is to participants of the multicast group, is also described in the following in an appropriate place, such as sending the multicast message of the multicast Center to the participants of or a multicast group can be realized via a logical connection.

According to <figref idrefs="S26">4</figref> sends UE4 a first message N1 "Activate PDP Context Request" (= "Activate PDP Context Request") to the SGSN 1. This message includes according to the invention an identification of the multicast group, hereinafter referred to as multicast address. The SGSN 1 detects the invention now that this is a multicast address in the address.

Below is a link in the direction from UE to GGSN as UL connection (uplink, ie uplink) and a compound of GGSN toward UE DL connection (downlink, ie, downlink) refers. It is also assumed for this embodiment that no connections between RNC1 and RNC2 SGSN 1 and SGSN 1 and have been established for the transmission of multicast messages to the group A, and the SGSN 1 is not known in whatCell to UE5 and UE1 are. Furthermore, it is assumed that the area in which the SGSN1 the UE5 and UE1 believed comprises cells that are associated with RNC1 and RNC2. The plan is to UE1 are in a cell, which is spanned by RNC2.

For simplicity is considered in the further connection establishment for UE5 and UE 4 in detail, as these are both in accordance with this embodiment, in cells that are associated with the RNC1. The SGSN 1 therefore now first sends a message N2 "Paging Request" (= "paging request", the so-called. Paging control radio calls referred) to the RNC 1 and encourages it to order, a message N3 "Paging Type 1" ( = "Pagingtyp 1") to send in all the cells in which the UE5 is suspected (the same is true for RNC 2 and UE1). The UE5 receives in one of the cells, the message N3 and then establishes a signaling connection N4 "RRC Connection" (= "RRC connection") to RNC1 on. In addition, with message N5 "service request" (= "Service Request") set up a signaling connection between UE5 and SGSN 1. Subsequently, the SGSN 1 a message N6 "Request PDP Context Activation" sends (= "Ask PDP Context Activation to") to UE5. Decides UE5 that it wants to establish a connection for the multicast group A, it sends a message N7 "Activate PDP Context Request" (= "Activate PDP Context Request") back to the SGSN 1. Now, the SGSN 1 knowledge of which UEs of the multicast group A are to which RNCs. In this embodiment, these are UE4 and UE5 to RNC1 and RNC2 to UE1. The SGSN 1 then sends a message N8 "Common RAB assignment request" (= "Common RAB Assignment Request") to the RNC 1 (the same applies of course again for UE1, a message is sent to the N8 at RNC2). According to this message contains a list of PDP contexts. Each PDP context, an identifier (TEID = Tunnel Endpoint IDentifier) ​​the connection between RNC 1 and SGSN 1 towards RNC1 to SGSN 1 (UL) is assigned. There is therefore a logical UL connection per PDP context, ie per UE of the multicast group A. In this embodiment, the identifier UL TEID1 denotes the UL connection between RNC 1 and SGSN 1 for UE 4 and UL-TEID2 the connection between RNC 1 and SGSN 1 for UE5. The RNC 1 now establishes connections to UE 4 and UE5. In<figref idrefs="S26">4</figref> this is ( "RB-construction completed" =) presented with the news N9 "RB Setup" (= "RB-building") and N10 "RB setup complete". Could the connections are established successfully ( "Common RAB assignment response" =) sends the RNC1 a message N11 "Common RAB assignment response" back to the SGSN 1. This message also contains a list of PDP contexts, but only an identifier (DL-TEID1) for the DL connection between RNC 1 and SGSN 1 towards SGSN 1 to RNC1. There is therefore only a logical DL connection for all PDP contexts, ie for all UEs of the multicast group A. According to RNC and SGSN so on the uplink or in the UL the PDP contexts each a logical connection and the DL the PDP contexts assign a common connection. be set up and the links to RNC2 analog. The UL connection between RNC2 and SGSN 1 for the identifier UE1 UL TEID3 is thereby assigned.

Because according to this embodiment in the area of ​​RNC2 merely consulted UE1 the multicast group A, the DL connection between RNC2 and SGSN 1 which is to be designated by the identifier DL TEID3, also assigned to only one PDP context.

The SGSN 1 has therefore now established connections to RNC1 and RNC2. Subsequently, the SGSN 1 a message N12 "Create PDP Context Request" (= "Create PDP Context Request") sends to the GGSN. This message contains a list of PDP contexts belonging to the multicast group A, in this embodiment, ie PDP contexts that are the UE5 1, 4 and 5 associated with, and a common identifier (DL-TEID4) for the DL connection between GGSN and SGSN 1. The GGSN detects the invention with reference to the multicast address that the PDP contexts describe a connection for the transmission of multicast messages. The GGSN then sends a message back N13 "Create PDP Context Reponse" (= "Create PDP Context Response") to the SGSN 1, which is also the list of the PDP includes present invention contexts, but any PDP context, an identifier for the UL connection is allocated between SGSN 1 and GGSN. The UL connection that is assigned to the UE 4, shall be assigned to the identifier UL TEID4, UE5 the identifier UL TEID5 and the UE1 the identifier UL TEID6. Messages received by the GGSN via the compounds represented by the identifiers UL TEID4-6 are thus forwarded to the multicast Center. Then a message N14 "Activate PDP Context Accept" (= "Activate PDP Context consent") returns the SGSN 1 to UE 1, UE 4 and UE5, bringing the UE5 the connection is confirmed.

The UE4 then its multicast message MCN1 sends via the established connection to the RNC1. RNC1 adds the MCN1 the identifier UL TEID1 the UL connection between RNC 1 and SGSN 1 for the PDP context of the UE 4 added. The SGSN 1 detects that the associated UL connection between the SGSN1 and GGSN is the compound with the identifier UL TEID4. The UL TEID1 is removed from the SGSN 1 from the message MCN1 and added, instead, the UL TEID4 and sent the message to the GGSN. The GGSN detects invention that messages that it receives via the connections with the identifiers UL TEID 4-6, are forwarded to the multicast Center. The GGSN removed so the UL TEID4 and sends the MCN1 to the MCC.

Does the MCC received the MCN1, the message is distributed to all UEs of the multicast group in the network of the provider. The connections to UEs managed by SGSN 1, it need not be constructed, as this has already been initialized by sending the message MCN1 of UE4. By providing a connection between SGSN and RNC in the direction of SGSN is for all UEs belonging to the multicast group A, up to the RNC, needs advantageously to the transmission of the multicast message MCN1 those UEs that are also dependent on the SGSN 1, no Another connection to take place.

The invention provides, after all, a way for a user equipment is, itself to be the source of the packet data and thus data to a group of subscriber devices on the same network as well as to recipients in external packet data networks, ie to send other operators' networks. It is particularly advantageous that the architecture of the UMTS network can be used. Essence of the invention is in this case in particular, to allow the transmission of multicast messages from a subscriber device to a multicast Center, which then redistributes the messages to all the users belonging to this multicast group.

The invention comprises, in addition to the inventive method and the corresponding devices which having respective means, in particular processor units and / or control units to implement the assigning of the connections to the described parameter sets and connection identifiers. Further comprising means for appending and deleting the connection identifiers are according to the invention provided at the Center for multicast transmitted from the subscriber unit multicast message, and in particular processor units and / or control units. Part of the invention are also a computer-readable storage medium on which a program is stored which enables a computer or microprocessor of the respective radio network control unit, or each subscriber device, after it has been loaded in the memory of the computer or microprocessor, method steps of the invention after the principle and execute its developments. Furthermore, the invention also relates to a computer program product comprising a computer readable storage medium on which a program is stored which enables a computer or microprocessor of the respective radio network control unit, or each subscriber device, after which it or in the memory of the computer has been microprocessor loaded to execute method steps of the inventive principle and its further developments.