CN1571531A - Method of reliable transmission of public control information in multimedia broadcasting and multicast service - Google Patents

Abstract

A method for ensuring reliable transmission of common control information in multimedia broadcast and multicast services, comprising the steps of: before starting the transmission of common control information, notifying all user terminal equipment UEs that they are ready to receive common control information; Limited public control information transmission; if the public control information is not received correctly on the public channel, the user terminal equipment UE requests the network to establish a dedicated channel for the transmission of public control information; the network establishes a dedicated channel for the requesting user terminal equipment UE ; The network transmits the common control information on the above-mentioned dedicated channel; after completing the transmission of the common control information, the network instructs the user terminal equipment UE to release the above-mentioned dedicated channel. The invention reduces the times of repeated transmission of common control information on the common channel, reduces the load of the common channel, increases the transmission capacity of the common channel, and reduces the influence of the transmission of the common channel on a dedicated channel.

Description

Method for Reliable Transmission of Common Control Information in Multimedia Broadcast and Multicast Service

technical field

The present invention relates to multimedia broadcast and multicast service (hereinafter referred to as MBMS), in particular to a method for ensuring reliable transmission of public control information in MBMS.

Background technique

MBMS is a new service for which relevant standards are being formulated in the third generation mobile communication system partnership project for standardization. The MBMS service is a one-way point-to-multipoint service (that is, multimedia data broadcast from a single data source is sent to multiple users for reception through network transmission). The biggest feature of this kind of business is that it can effectively utilize wireless resources and network resources. MBMS services are mainly used in wireless communication network systems, such as broadband code division multiple access communication systems and global mobile communication systems. The transmission of business data in MBMS basically goes through several processes: data source transmission, intermediate network transmission, destination cell air transmission, and user reception. Fig. 1 is a logical network equipment diagram of a wireless communication system capable of providing MBMS services. In this figure, MBMS actually utilizes a General Packet Radio Service (hereinafter referred to as GPRS) network as a core transmission network. As shown in Figure 1, the broadcast and multicast service center (hereinafter referred to as BM-SC) is the data source for sending MBMS service data; the gateway GPRS support node (hereinafter referred to as GGSN) is used for the communication between the GRPS network and the external network (such as the Internet network) Connection; in the MBMS business, the gateway GPRS support node connects to BM-SC and sends MBMS data to a specific serving GPRS support node (hereinafter referred to as SGSN); the cell broadcast center is the data source of the cell broadcast, and in MBMS, the cell broadcast center It is interconnected with BM-SC so that the cell broadcast center can provide the MBMS service announcement function; SGSN is used for UE access control and mobility management and at the same time sends MBMS data from GGSN to a specific radio unit controller (hereinafter referred to as RNC) ); RNC is used to control a group of base stations and transmit multimedia data to a specific base station; the base station (hereinafter referred to as Node-B) establishes an air data transmission channel for the MBMS service of a certain cell under the control of RNC; the user A terminal device (hereinafter referred to as UE) is a terminal device that receives MBMS data.

In a wireless communication network system, the information exchange between a user and the network system is completed through the transmission channel. MBMS service data must also be transmitted to the end user through a suitable transmission channel. There are generally two types of transmission channels in a wireless communication network system: a dedicated channel occupied by a single user alone or a common channel shared by multiple users. Generally speaking, point-to-point (that is, data sent from a data source is sent to a user to receive through network transmission) data transmission is completed through a dedicated channel, while point-to-multipoint data transmission is completed through a public channel. In the MBMS service, in order to effectively utilize radio resources and network resources, RNC can determine the type of channel that should be selected according to the actual situation in a cell.

Normally, the RNC determines the channel type to be selected for MBMS service data transmission in a cell according to the number of people using the same MBMS service in a cell. When the number of users using the same MBMS service is small, the MBMS channel type should be a point-to-point dedicated channel; when the number of users of this service exceeds a certain threshold, the MBMS channel type should be a point-to-multipoint common channel. In addition, the RNC can also determine the type of channel to be selected according to other criteria such as the transmit power of a cell.

In the MBMS service, in addition to the MBMS service data need to be transmitted to the end user, some control information related to the MBMS service also needs to be transmitted to the end user. These control information can be divided into two categories: one type is related to a single end user, such as authentication information for an end user; but more control information is the other type, that is, common control information for multiple users, For example, the paging prompt information for the user when the service data is ready to be transmitted, and the decryption information required for decrypting the service data.

Also in consideration of effective use of wireless resources and network resources, usually the transmission of control information related to a single user is transmitted using a dedicated channel; the transmission of public control information related to services is transmitted using a common channel.

Generally, a certain transmit power is selected for information transmitted on a common channel in a cell to ensure that the cell can be basically covered, that is, all user terminals within the cell can receive it under normal conditions. In contrast, the transmission power of a dedicated channel for a specific user can be controlled and changed according to the actual situation; if the user is far away from the transmitting base station, or due to factors such as the user's location, the user receives When the signal strength of the user decreases, the transmission power of the dedicated channel for this user can be increased accordingly; and when the distance between the user and the transmitting base station is relatively short, or when the signal strength received by the user is compared due to factors such as the specific location of the user, the transmission power for the dedicated channel can be increased accordingly. The transmit power of the user's dedicated channel can also be reduced accordingly.

Due to the characteristics of wireless signal transmission, in a mobile communication system, generally there are places in a cell where the reception signal is not good or even no signal at all, which is also an inherent characteristic of the mobile communication system itself. At the same time, due to the mobility and autonomy of the end users, the end users may be in these places sometimes. At this time, these end users cannot correctly receive the common control information of the MBMS service transmitted on the common channel. In addition, due to the autonomy of the end user, the user terminal equipment may sometimes be in some specific states, so it cannot correctly receive the common control information of the MBMS service transmitted on the common channel.

Usually, the common control information can be repeatedly transmitted on the common channel, so as to reduce or even avoid the occurrence of this situation. But this will increase the information transmission on the already very busy public channel, which will bring additional load to the system; at the same time, since the public channel needs to guarantee a certain transmission power, this will bring a certain impact on the transmission of the dedicated channel , thereby reducing the capacity of the system. In addition, users may still not receive these public information, also due to their mobility and autonomy.

Contents of the invention

Therefore, the purpose of the present invention is to provide a transmission method that effectively utilizes radio resources and network resources, reduces system load and impact on the system, and at the same time ensures reliable transmission of public control information.

In order to achieve the above object, a method for ensuring reliable transmission of public control information in multimedia broadcast and multicast services, comprising steps:

1) Before starting the transmission of the common control information, notify all user terminal equipment UEs to prepare to receive the common control information;

2) Transmission of common control information with a limited number of repetitions on the common channel;

3) If the common control information is not received correctly on the common channel, the user terminal equipment UE requests the network to establish a dedicated channel for transmission of the common control information;

4) The network establishes a dedicated channel for the requesting user terminal equipment UE;

5) The network transmits the public control information on the above-mentioned dedicated channel;

6) After completing the transmission of the common control information, the network instructs the user terminal equipment UE to release the above-mentioned dedicated channel.

The invention reduces the number of repeated transmissions of common control information on the common channel, reduces the load of the common channel, increases the transmission capacity of the common channel, reduces the impact of the common channel transmission on a dedicated channel, and increases the system capacity. It alleviates or avoids that the user may not receive the MBMS common control information due to the mobility and autonomy of the user, and improves the reliability of receiving the common control information.

Description of drawings

Fig. 1 is the wireless communication system logical network equipment diagram of MBMS business;

Fig. 2 has demonstrated the work flowchart of the BMSC of the updating process of the MBMS service data decryption key of application one embodiment of the present invention;

Fig. 3 is a working flowchart of the user terminal equipment UE corresponding to Fig. 2;

Fig. 4 has demonstrated the working flowchart of the RNC that has applied the MBMS service parameter notification process of two embodiments of the present invention;

FIG. 5 is a flowchart of the operation of the UE corresponding to FIG. 4 .

Detailed ways

The present invention relates to a transmission method suitable for MBMS services, which effectively utilizes wireless resources and network resources, reduces system load and impact on the system, and at the same time ensures the transmission of reliable public control information; The number of times the common control information is repeatedly transmitted on the channel; the user terminal equipment UE that has not correctly received these common control information can effectively use the wireless network by requesting to use a dedicated channel that can perform power control and thus be more reliable to receive these common control information. Resources and network resources, reducing system load and impact on the system, while ensuring the purpose of transmitting reliable public control information. Referring to the accompanying drawings, two embodiments of the present invention are given below. In order to avoid making the description of this patent too lengthy, in the following description, detailed descriptions of functions or devices that are well known to the public are omitted.

first embodiment

Fig. 2 demonstrates the working flow chart of BMSC applying an update process of MBMS service data decryption key according to an embodiment of the present invention. FIG. 3 is a working flowchart of the user terminal equipment UE corresponding to FIG. 2 . In this embodiment, the BMSC and the user terminal equipment UE agree in advance to update the decryption key at regular intervals.

201. BMSC in the above Fig. 2 judges whether it is time to update the decryption key. If the agreed time arrives, the BMSC proceeds to process 202 . Otherwise, the BMSC waits and proceeds with process 201 .

202. The BMSC in FIG. 2 above starts the timer, and transmits the updated service data decryption key on the common channel through the RNC.

203. BMSC in FIG. 2 above judges whether to continue to wait to receive a request for transmitting a service data decryption key that may come from the user terminal equipment UE according to whether the timer in process 202 expires. Before the timer expires, the BMSC executes process 204; if the timer expires, the BMSC returns to execute process 201.

204 in the above FIG. 2 , if there is a user terminal equipment UE requesting to transmit the service data decryption key, then the BMSC executes the process 205 ; otherwise, the BMSC returns and proceeds to the process 203 .

205. The BMSC in FIG. 2 above guides the UE to establish the UE-specific channel through the RNC.

206. The BMSC in FIG. 2 transmits the updated service data decryption key on the dedicated channel established in the above process through the RNC. After the transmission process is completed, the RNC instructs the UE to release the dedicated channel in the above process, and the BMSC returns to process 203 .

301. UE in FIG. 3 above judges whether it is time to update the decryption key. If the appointed time arrives, the UE proceeds to process 302 . Otherwise, the UE waits and proceeds to process 301 .

302. The UE in FIG. 3 above attempts to receive the service data decryption key transmitted on the common channel.

303 in the above FIG. 3 . If the UE can receive correctly in the above 302 process, then the UE returns to perform the process 301 . Otherwise, proceed to process 304 .

304 in Fig. 3 above, the UE requests the BMSC to transmit the service data decryption key through the RNC.

305. UE in the above Figure 3 establishes a dedicated channel under the guidance of the RNC.

306. The UE in FIG. 3 above receives the service data decryption key from the BMSC on the above channel.

307. The UE in FIG. 3 above releases the dedicated channel in the above process under the guidance of the RNC after completing the above process. After completion, the UE returns to process 301 .

second embodiment

Fig. 4 demonstrates the working flowchart of the RNC applying the MBMS service parameter notification process of the two embodiments of the present invention. FIG. 5 is a flowchart of the operation of the UE corresponding to FIG. 4 . In this embodiment, the service parameter notification from the RNC is sudden, that is, the UE cannot know in advance when the RNC will give the service parameter notification.

401. The RNC in Figure 4 above decides to notify the service parameters.

402. RNC in the above Fig. 4 starts the timer, and transmits the service parameters on the common channel.

403. The RNC in FIG. 4 above judges whether to continue to wait for a request from the UE to transmit service parameters according to whether the timer in the procedure 402 expires. Before the timer expires, the RNC executes process 404; if the timer expires, the RNC ends the notification process.

404 in the above Fig. 4. If there is a UE request to transmit service parameters, then the RNC executes the process 405; otherwise, the RNC waits and proceeds to the process 403.

405. RNC in the above Fig. 4 instructs the user terminal equipment to establish a dedicated channel for the user terminal equipment.

406. The RNC in FIG. 4 transmits service parameters on the dedicated channel.

407 in the above-mentioned Figure 4. After the transmission process is completed, the RNC instructs the user terminal equipment UE to release the above-mentioned dedicated channel. After completion, the RNC returns to the execution process 403 .

501 in FIG. 5 above. The UE periodically monitors the common channel.

502. UE in the above-mentioned FIG. 5 judges whether there is information it needs on the common channel. If there is information it needs, the UE proceeds to process 503 . Otherwise, the UE waits and proceeds to process 501 .

503. The UE in FIG. 5 above tries to receive the service parameters transmitted on the common channel. If it can be received correctly, then the UE returns to the execution process 501 . Otherwise, proceed to process 504 .

504 in the above Figure 5. The UE requests the RNC to transmit service parameters.

505 in the above Figure 5. The UE establishes a dedicated channel under the guidance of the RNC.

506 in the above-mentioned Figure 5. The UE receives the service parameters from the RNC on the above-mentioned channel.

507. The UE in FIG. 5 above releases the dedicated channel in the above process under the guidance of the RNC after completing the above process. After completion, the UE returns to process 501 .

Claims (4)

1. A transmission method for public control information in multimedia broadcasting and multicasting services, characterized in that it comprises steps: a) Before starting the transmission of the common control information, notify all user terminal equipment UEs to prepare to receive the common control information; b) Transmission of common control information with a limited number of repetitions on a common channel; c) If the common control information is not received correctly on the common channel, the user terminal equipment UE requests the network to establish a dedicated channel for transmission of the common control information; d) The network establishes a dedicated channel for the requesting user terminal equipment UE; e) The network transmits the public control information on the above-mentioned dedicated channel; f) After completing the transmission of the common control information, the network instructs the user terminal equipment UE to release the above-mentioned dedicated channel. 2. The transmission method according to claim 1, characterized in that in step a), the network and the user terminal equipment UE agree in advance to start the transmission of the common control information at a certain time. 3. The transmission method according to claim 1, characterized in that in step a), the network notifies the user terminal equipment UE to start receiving common control information through MBMS paging. 4. The transmission method according to claim 1, characterized in that in step a), the UE periodically monitors the common channel to determine whether there is common control information required by itself on the common channel.

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