AU3817699A

AU3817699A - Radio telecommunication system, with transmission of user data on a signaling channel

Info

Publication number: AU3817699A
Application number: AU38176/99A
Authority: AU
Inventors: Ulrich Barth; Christoph Sperber
Original assignee: Alcatel CIT SA; Alcatel SA
Current assignee: Alcatel Lucent SAS
Priority date: 1998-04-17
Filing date: 1999-04-16
Publication date: 1999-11-08
Also published as: EP0951192A1; JP2002505829A; WO1999055109A1; HUP0003304A2

Description

Radio Telecommunication System, with Transmission of User Data on a Signaling Channel The invention relates to a wireless telecommunications system with at least one base station and with at least one mobile subscriber terminal in accordance with the preamble of Claim 1 and a base station as well as a subscriber terminal in accordance with the preamble of one of the independent claims. US-A-5371 781 discloses a wireless telecommunications system wherein mobile subscriber terminals and base stations are in radio communication with each other. The base stations send a so-called TCLID (terminating called party identification) during the paging phase (paging) to the called subscriber terminal. This identification is informative data indicating which subscriber is being called. As described in this document in Column 2, Paragraph 1, the TCLID may be sent together with signaling data, namely the ring signal (ringing message). Accordingly, informative data, namely the TCLID, is at least occasionally sent on the signaling channel provided for transmission of signaling data. On arrival of a call at a subscriber terminal, this TCLID makes it possible to determine which 4 subscriber is being called. This permits a plurality of subscribers to be called individually via a single subscriber terminal. WO-A-94/05095 discloses a wireless telecommunications system wherein informative data is transmitted in the form of packet data via a so-called organization channel, i.e., via a signaling channel. Due to this packet data transmission, no through-connection needs to be provided. Rather, the informative data can be nested with the signaling data and transmitted together via the existing signaling channel. The book entitled "The GSM, Global System for Mobile Communications" by M. Mouly and M. B. Pautet, privately published in 1992, Palaiseau, France, Chapter 6.1.2, pp. 317 through 321, describes the sending of such paging signals in a wireless telecommunications system. The telecommunications system described therein is the GSM mobile telephone system, which comprises base stations that send radio signals to mobile subscriber terminals, so-called "mobile stations," on a signaling channel, a so-called "paging channel." The radio signals sent on the signaling channel contain "paging messages" and "initial assignment messages." This means that messages for the execution of the paging procedure and the initialization procedure are transmitted on the signaling channel. These messages are thus signaling data. For the transmission of informative data, the described telecommunications system provides so-called "traffic channels." The invention is based on the finding that a signaling channel, on which at least occasionally informative data may be transmitted, can be used also to send information on the calling subscriber to the called subscriber. This makes it possible for the called subscriber to receive this information even if he has not yet been assigned a traffic channel. The inventive wireless telecommunications system has at least one base station that sends signaling data and informative data containing information on the calling subscriber on the signaling channel to one of the telecommunications terminals for call connection setup. The informative data is preferably text, picture, or voice data providing information on the requested call connection, particularly the subscriber number of the calling subscriber or the telecommunication service requested by the calling subscriber. A base station and a mobile subscriber terminal for such a wireless telecommunications system are also proposed. It is particularly advantageous if the informative data is used to combine a plurality of subscriber terminals into a paging group that receives a common paging signal. This is accomplished in that the informative data contains an identification of these subscriber terminals and that the base station sends a corresponding paging signal to these subscriber terminals, which then form a paging group. Particularly advantageous embodiments of the invention result from the subclaims.

Below, the invention is explained in further detail by means of an exemplary embodiment and with the aid of the following figures: Figure 1 schematically shows the setup of a wireless telecommunications network; Figure 2 is a schematic representation of the radio transmission on the signaling channel; Figure 3 shows the structure and contents of the data transmitted on the signaling channel. Figure 1 is a schematic representation of a wireless telecommunications system CTS with a plurality of base stations, of which two, BS1 and BS2, are shown by way of example. The wireless telecommunications system furthermore comprises a plurality of mobile subscriber terminals, of which three, MX, MY, and MZ, are shown by way of example. Each base station serves a cell, i.e., the telecommunications system is a cellular radio system. The subscriber terminals located within the cell receive radio signals from the base stations on a signaling channel PCH. The subscriber terminals MX and MY are registered in the cell served by base station BS1 and accordingly receive radio signals from this base station BS1. If the subscriber terminal subsequently registers, for example, in the cell served by the other base station BS2, it will receive radio signals from this base station BS2. The signaling channel symbolically represented in Figure 1 is a broadcast signaling channel PCH, on which the base stations send broadcast signals for call setup to the mobile subscriber terminals. A broadcast signal is sent whenever a call connection to one of the mobile subscriber terminals (a so-called "mobile terminated call") is to be set up. For this purpose, conventional signaling data is transmitted. According to the invention, informative data is also transmitted at least occasionally on the signaling channel PCH.

In the exemplary embodiment shown in Figure 1, the mobile subscriber terminals MX and MY receive the same broadcast signal from base station BS1. The mobile subscriber terminal MX, which is also located within the radio field range of the other base station BS2, moreover receives a broadcast signal from this base station BS2. Subscriber terminal MZ is not being called so that no broadcast signal is sent in the direction of this subscriber terminal. Figure 2 schematically shows the radio transmission on the signaling channel between the base station BS1 and the subscriber terminals MX and MY. The radio signals are transmitted according to the TDMA procedure, i.e., within a predefined time pattern, which in this case is a multiframe MF comprising 52 TIDMA frames. The multiframe MF comprises a plurality of time intervals, in this case three time intervals IDL1 through IDL3, which are reserved for executing the paging procedures. The multiframe MF furthermore comprises a first time interval REG, which is reserved for executing a registration procedure. The partitioning of the multiframe MF is indicated by the information of the frame number FN, which in this case is between 1 and 52. The base station is sending on the down channel DL within logic channels PCH and AGCH, which will be described below. The subscriber terminals are sending on the up channel UL within another logic channel RACH, which will be described below. A first radio frequency is used for transmission on the down channel DL and a second radio frequency for transmission on the up channel. In this case, for example, the duplex distance between the two radio frequencies is 45 MHz. At the start of the multiframe MF in the time frame with the numbers FN = 1, the base station sends a broadcast signal on the broadcast channel BCH, which contains information for all the subscriber terminals located within the cell. This information is, for example, the identification of the base station and synchronization data for synchronizing the subscriber terminals to the time standard of the base station. With the sending of the broadcast signal within time frame FN = 1, the time interval REG begins, i.e., the registration phase in which the subscriber terminals can register with the base station. The time interval REG for registration is followed by a plurality of time intervals for executing paging procedures. In this example, three time intervals IDL1 through IDL 3 are provided for this purpose. Accordingly, three different subscriber terminals or three different paging groups can be addressed. For these time intervals IDLI through IDL3, the radio transmission in time interval IDLI is described in further detail by way of example. First, the base station on the down channel DL sends four consecutive paging bursts on the paging channel PCH. These paging bursts contain both signaling data and informative data, by means of which certain subscriber terminals are addressed, either individually or as paging groups. In this example, the subscriber terminals MX and MY are addressed jointly as a paging group. After receiving the paging bursts, the addressed subscriber terminals answer on the up channel UL by returning four consecutive access bursts RA on the access channel RACH to the base station. Subsequently, the base station confirms receipt by sending four access grant bursts on the access grant channel AGCH. With this, time interval IDL1 is concluded and paging per se is terminated. During the following time intervals IDL2 and IDL3 additional subscriber terminals can then by addressed by means of other paging signals. Figure 3 schematically shows the structure of the data transmitted on the signaling channel PCH. The data is 8-bit value signaling data and informative data transmitted in the form of the aforementioned paging bursts. A total of eight such words are transmitted, i.e., eight octets, OCT1 through OCT8 with the following content: the first octet OCT1 contains a first signaling datum IEI, which gives the identification of the called subscriber terminal. The second octet OCT2 contains a second signaling datum LMIC giving the length of the content of the identification. The third octet OCT3 corresponds to a third signaling datum containing an identification digit IDG, a check bit indicator OEI, and information on the type of the identification TID. Octets OCT4 and OCT5 contain information on the temporary identification of the called subscriber terminals. This information TMSI corresponds to a shortened form of the TMSI known from the GSM standard (temporary mobile subscriber identity). The shortened form is created by BCD coding. In addition to the above signaling data, informative data is also transmitted on the paging channel, i.e., in the form of octets OCT6 through OCT8. This informative data DAT contains information that is not required for call setup per se but has purely informational character. The informative data DAT is evaluated on receipt by the subscriber terminal and output in the form of text, pictures, or voice. In this example, the informative data given is the subscriber number and the name of the calling subscriber. This informative data is output as text data on the subscriber terminal display. Thus, the subscriber receives extensive information on the calling subscriber even during call setup. In this example, the transmission also includes informative data indicating which telecommunication service is requested by the calling subscriber. Accordingly, the called subscriber can see even during call setup whether the calling subscriber is requesting, for example, a fax service or a short-message service. The informative data also contains the identifications of the subscriber terminals, which jointly form a paging group. In this example, the subscriber terminals MX and MY (see Fig. 1) are jointly addressed on the paging channel PCH. Figure 3 also shows different bit patterns A, B, C, and D of the first octet OTCl by way of example. These different bit patterns are meant to indicate the type of paging signal. The first bit pattern A indicates that only signaling data for the U paging itself is being transmitted. The second bit pattern B indicates that signaling data in the form of BCD coded words is being transmitted. The third bit pattern C indicates that informative data for a specific telecommunication service is also being transmitted, e.g., for the short-message service. The fourth bit pattern D indicates that the subscriber terminal is to remain in so-called "idle mode" and to wait for the receipt of informative data sent in a subsequent multiframe.

Claims

1. Wireless telecommunications system (CTS) with at least one mobile subscriber terminal (MX, MY) and with at least one base station (BS1, BS2), which sends signaling data (IEl, LMIC) and at least occasionally informative data (DAT) on a signaling channel (PCH) for reception by the at least one mobile subscriber terminal (MX, MY), characterized in that the base station (BS1) sends the signaling data (IEI, LMIC) and the informative data (DAT) for call connection setup from a calling subscriber to a telecommunications terminal (MX) and that the informative data contains information on the calling subscriber.

2. Wireless telecommunications system (CTS) according to Claim 1, characterized in that the informative data (DAT) indicates the subscriber number of the calling subscriber and/or the telecommunications service requested by the calling subscriber. 2

3. Wireless telecommunications system (CTS) according to Claim 1, characterized in that the informative data (DAT) is alphanumeric data, which the subscriber terminal (MX) receives and displays on a display field.

4. Wireless telecommunications system (CTS) according to Claim 1, characterized in that the signaling data (IEl, LMIC) sent by at least one base station (BS1, BS2) indicates whether the informative data (DAT) is text, picture, or voice data.

5. Wireless telecommunications system (CTS) according to Claim 1, characterized in that the base station (BS1) sends the signaling data (IEl, LMIC) and the informative data (DAT) as a paging signal on a frequency monitored by the at least one mobile subscriber terminal (MX, MY).

6. Wireless telecommunications system (CTS) according to Claim 1, characterized in that the signaling data (IEl, LIMC) and/or informative data (DAT), which is sent by the base station (BS]) within the paging signal, contains an identification for the at least one subscriber terminal (MX, MY) and that the base station (BS1) sends this one paging signal to at least two of the subscriber terminals (MX, MY) so that these subscriber terminals (MX, MY) form a paging group. 3

7. Wireless telecommunications system (CTS) according to Claim 6, characterized in that the base station (BS1), within a predefined time frame (MF) comprising a plurality of time intervals (IDL1, IDL1, IDL3), sends call signals to different paging groups at these time intervals (IDL1, IDL2, IDL3).

8. Wireless telecommunications system (CTS) according to Claim 6, characterized in that the informative data (DAT) sent by the base station (BS1) contains information on the subscriber terminals (MX, MY) belonging to the paging group, particularly their identification and/or the names of the corresponding subscribers.

9. Base station (BS1) for a wireless telecommunications system (CTS), which sends signaling data (IEl, LMIC) on a signaling channel (PCH) to at least one mobile subscriber terminal (MX, MY) and which at least occasionally sends informative data (DAT) on the signaling channel (PCH) for reception by the at least one mobile subscriber terminal (MX, MY) characterized in that the base station (BS1) sends the signaling data (IEI, LMIC) and the informative data (DAT) for call connection setup from a calling subscriber to one of the telecommunications terminals (MX) and that the informative data contains information on the calling subscriber. 4

10. Mobile subscriber terminal (MX) for a wireless telecommunications system with at least one base station (BS1, BS2), which receives signaling data (IEI, LMIC) on a signaling channel (PCH), which is sent by the at least one base station (BS1), and which receives informative data (DAT) on the signaling channel (PCH), which is sent at least occasionally by the at least one base station (BS1, BS2), characterized in that the base station (BS1) sends the signaling data (IEI, LMIC) and the informative data (DAT) for call connection setup from a calling subscriber to one of the telecommunications terminals (MX) and that the informative data contains information on the calling subscriber.