WO2007112696A1

WO2007112696A1 - Method and system for realizing multimedia broadcast multicast service

Info

Publication number: WO2007112696A1
Application number: PCT/CN2007/001090
Authority: WO
Inventors: Xiaodong Zhang; Hao Hu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-04-06
Filing date: 2007-04-04
Publication date: 2007-10-11
Also published as: CN101052203B; CN101052203A

Abstract

A method and a system for realizing multimedia broadcast multicast service are disclosed. During receiving the multimedia broadcast multicast service in a SFN network, the user equipment obtains the idle transmission interval time slot in a transmission interval between two successive frames or in a transmission interval of a frame via the compression mode or data scheduling by the schedule unit; the user equipment could handover to the LTE network (or other networks) to perform measurement, registration or paging respondence as required. The user equipment could handoff to the LTE network to perform cell reselection or location area update during the transmission interval time slot based on the measurement results. When receiving a call, the user equipment could handoff to the LTE network to send a rejection-receiving-message or receive corresponding service during the transmission interval time slot.

Description

Method and system for realizing multimedia broadcast multicast service. The present application claims to be filed on April 06, 2006 in the Chinese Patent Office, the application number is 200610060203.5, and the invention is entitled "Implementation Method of Multimedia Broadcast Multicast Service". Priority is hereby incorporated by reference in its entirety. Technical field

The present invention relates to the field of wireless communication and broadcast multicast technologies, and in particular, to a multimedia broadcast and multicast technology in a wireless network, and more particularly to a method and system for implementing a multimedia broadcast multicast service. Background technique

Multicast and broadcast are technologies that transfer data from one data source to multiple destinations. In a conventional mobile communication network, a cell multicast service or a cell broadcast service (CBS) allows low bit rate data to be transmitted to all users through a cell shared broadcast channel, which belongs to a message type service.

Nowadays, the demand for mobile communication is no longer satisfied with the telephone and message services. With the rapid development of the Internet, a large number of mobile multimedia services have emerged. Some of the mobile multimedia services require multiple users to receive the same data at the same time. Examples include video on demand, TV broadcasts, video conferencing, online education, interactive games, and more. Compared with general data services, these mobile multimedia services have the characteristics of large data volume, long duration, and delay sensitivity. Current Internet Protocol (IP) multicast and broadcast technologies are not suitable for mobile communication networks because mobile communication networks have a specific network structure, functional entities, and wireless interfaces that are different from wired communication IP networks.

In order to effectively utilize mobile communication network resources, the industry proposes a Multimedia Broadcast Multicast Service (MBMS) for mobile communication networks, thereby providing a point in the mobile communication network to send data from one data source to multiple users. Multi-point service, realize network resource sharing, improve network resource utilization, especially air interface resources. The proposed MBMS can not only realize plain text low-rate message class multicast and broadcast, but also realize multicast and broadcast of high-speed multimedia services to adapt to the future development trend of mobile data.

FIG. 1 is a schematic diagram of a structure of a wireless network supporting broadcast/multicast services. As shown in FIG. 1, a wireless network entity supporting a broadcast/multicast service is a broadcast/multicast service server (BM-SC) 101. The BM-SC 101 is connected to a Gateway GPRS Support Node (GGSN) 102 via a Gmb interface or a Gi interface, and one BM-SC 101 can be connected to multiple GGSNs; the GGSN 102 communicates with a serving GPRS support node via a Gn/Gp interface. (SGSN, Serving GPRS Support Node) 103 is connected, one GGSN 102 can be connected to multiple SGSNs 103; SGSN 103 can be connected to Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) 104 via Iu interface, and then UTRAN 104 The UE (User Equipment) 106 is connected through a Uu interface, and the SGSN 103 can also be connected to the Global System for Mobile Communications Enhanced Radio Access Network (GERAN) 105 via the Iu/Gb interface, and then the GERAN 105 is connected to the UE 107 via the Um interface. Among them, the GGSN and the SGSN belong to nodes in the core network (CN) in the wireless network.

In order to support the MBMS service, a mobile network function entity-broadcast/multicast service server is added in the mobile communication system, that is, the BM-SC shown in FIG. 1, which is an entry of the content provider for authorization and on the mobile network. Initiate the MBMS service and deliver the MBMS content according to the scheduled schedule. In addition, MBMS-related functions are added to functional entities such as UE, UTRAN GERAN, SGSN, and GGSN.

The MBMS includes the multicast mode and the broadcast mode. The multicast mode requires the user to subscribe to the corresponding multicast group, perform service activation, and generate corresponding accounting information. Since the multicast mode and the broadcast mode differ in service requirements, the respective service processes are different. Figure 2 is a schematic diagram of the business process of the MBMS multicast mode.

Referring to FIG. 2, the processing involved in the MBMS multicast service includes: subscription, service announcement, user joining, session start, MBMS notification, MBMS notification, Data transfer, session stop, and user exit (Leaving). Figure 3 is a schematic diagram of the service flow of the MBMS broadcast mode. As shown in Figure 3, the MBMS broadcast mode service processing process includes: service announcement, session start, MBMS notification, data transfer, Session Stop (Session Stop). During the start of the session, the BM-SC prepares the data transmission and informs the network to establish the bearer resources of the corresponding core network and the access network. The MBMS notification procedure is used to notify the UE of the MBMS multicast session by the Radio Network Controller (RNC). Coming soon; in the data transmission process, the BM-SC transmits data to the UE through the bearer resources established during the start of the session, and the MBMS service has two modes when transmitting between the UTRAN and the UE. Type: Point-to-multipoint (PTM) mode and point-to-point (PTP) mode. The ΡΤΜ mode transmits the same data through the MBMS point-to-multipoint traffic channel (MTCH). All UEs that join the multicast service or are interested in the broadcast service can The receiving mode transmits data through the DTCH logical channel, and only one corresponding UE can receive the data; after the session ends, the bearer resource is released.

Currently, the MBMS service is carried over existing transmission channels and physical channels, using existing frequencies and bandwidths, and the like. The provision of the MBMS service can be divided into three phases:

First, the network does not provide any MBMS service during the period before the session starts. The user may be constantly trying to read the MBMS notification information. In this stage, the user can join any service at any time.

Second, the UTRAN receives a Session Start from the core network until the UTRAN establishes a Radio Bearer (RB) for the service. The UTRAN will notify the user to receive the MBMS service and perform a counting process on the MBMS service in order to determine the bearer type. At this stage, the UE may receive the MBMS Control Channel (MCCH) in response to counting to obtain relevant control information.

Third, the user starts to receive the MBMS service until the UTRAN obtains a session stop from the core network.

In the above process, the UTRAN sends MBMS control information to the UE through the MCCH. Since the current MBMS uses the same carrier frequency band (referred to as carrier frequency) as the WCDMA system, the transmission of control information on the MCCH channel is performed through the carrier frequency band of the existing network, that is, the UE does not have the selected carrier frequency band to receive the MBMS control information. The problem.

Due to the large number of types of services involved in the MBMS system, from background services (such as software downloads) to real-time services such as video browsing. As the number of service providers SP increases, the number of services will continue to increase. Currently, MBMS is an enhancement of the existing WCDMA system, which uses existing WCDMA resources, including transport channels and physical channels. MBMS occupies a large amount of existing wireless resources, which causes the existing business to be greatly affected; the types of services that MBMS can provide at the same time are limited.

When the MBMS service is implemented in the existing mobile communication system, the frequency band resource allocation of the system is mainly symmetrically allocated by using the uplink and downlink resources. However, most of the MBMS services are data-type services, and the upstream and downstream resources are asymmetric. Especially for some MBMS services, such as mobile TV services, uplink resources are not used at all, and video-on-demand services are used up. Resource It is also much smaller than the downlink resources. Then, if the existing system or the LTE system is used to implement the MBMS service, a huge waste of uplink resources is caused.

In order to avoid the huge waste of uplink resources caused by MBMS services in a mobile communication system, such as a Long Term Evolution (LTE) system, a Single Frequency Network (SFN) can be used to carry MBMS services. A new single-carrier broadcast multicast system is formed by coordinating cooperation between the separately allocated downlink carriers and the existing symmetric uplink and downlink carriers. Separate allocation 7 | In the MBMS service system, the separate MBMS carrier frequency can carry more MBMS services, which can more fully, efficiently and reasonably utilize wireless resources. However, the inventor found in the research process that when the UE is in the normal working condition of the mobile communication network, the UE can perform services such as calling, and only the MBMS service can be received under the SFN network. When the UE does not receive the MBMS service, it is in the mobile communication network, and the UE enters the SFN network only when MBMS service reception is required. In the prior art, when the UE registers with the mobile network or performs other services (such as voice service, etc.), it can no longer receive the signal of the SFN network, which may cause the video stream to be interrupted. Summary of the invention

Embodiments of the present invention provide a method and system for implementing a multimedia broadcast multicast service in a wireless communication system, to ensure that when a user equipment receives an MBMS service in a single frequency network SFN network, it can still communicate with a mobile communication network, such as long term evolution ( LTE, Long Term Evolution) The network remains in normal contact.

An embodiment of the present invention provides a method for implementing a multimedia broadcast multicast service, where a user equipment receives a multimedia broadcast multicast service in a single frequency network SFN network, including:

Obtaining a transmission interval slot in the process of receiving the multimedia broadcast multicast service;

The measurement, registration, or response paging is performed in the second network outside the SFN network in the transmission interval slot.

An embodiment of the present invention provides a system for implementing a multimedia broadcast multicast service, including: a single frequency network SFN, configured to release multimedia broadcast multicast service data;

a wireless communication network for transmitting wireless communication service data;

The user equipment UE receives the multimedia broadcast multicast service data in the single frequency network SFN; and obtains the idle transmission interval in the process of receiving the multimedia broadcast multicast data in the SFN network. The time slot, the user equipment switches to a wireless communication network outside the SFN network at a corresponding transmission interval slot for measurement, registration, or response paging.

In the technical solution provided by the embodiment of the present invention, the user equipment receives the multimedia broadcast multicast service in the single-frequency network SFN network, and obtains the transmission interval time slot in the process of receiving the multimedia broadcast multicast service; The slot switches to a second network outside the SFN network for measurement, registration, or response paging. When the user equipment receives the multimedia broadcast multicast service in the SFN network, it can perform measurement, registration, or response paging in the mobile communication network. Moreover, when a call or a page for the UE is initiated in the mobile communication network, the network can send the paging notification information to the user equipment according to the current location and the cell of the user equipment, and the user equipment can A corresponding response is required. DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1 is a schematic structural diagram of a wireless network supporting broadcast/multicast services in the prior art; FIG. 2 is a schematic diagram of a service flow of an MBMS multicast mode in the prior art;

3 is a schematic diagram of a service flow of an MBMS broadcast mode in the prior art;

4 is a schematic diagram of a conventional transmission interval slot obtained by compression;

Fig. 5 is a flow chart showing measurement at a predetermined cycle in the embodiment of the present invention. detailed description

In order to make the principles, features, and advantages of the present invention clearer, the present invention will be described in detail by taking a multimedia broadcast multicast service in an LTE network as an example.

The frequency band resource of the SFN is a fixed frequency band resource. It has only downlink resources and no uplink resources. The MBMS service data is mainly sent in the form of broadcast. The introduction of a single frequency network can avoid the huge waste of system resources caused by the low utilization of uplink resources, and facilitate the efficient use of system resources.

Therefore, the introduction of a new carrier frequency band to carry the MBMS service and coordinate with the original carrier can overcome the limitation of the air interface to the MBMS service capacity.

When the user terminal UE switches from the LTE network to the SFN network or directly to the SFN network to receive the MBMS service, since the frequency band of the SFN network is different from the frequency band of the LTE network, the UE of the single receiver cannot receive two UEs at the same time. Network information, so it is connected to the LTE network The system will be interrupted.

In the embodiment of the present invention, when the UE receives the MBMS service in the SFN network, the UE may switch to the frequency band of the LTE network during the idle time between the transmission intervals (the transmission gap between two frames or within one frame). Measure, register, or respond to a page. Such transmission interval time slots can be implemented by a method using a compressed mode, such as speeding up the data transmission rate, increasing the instantaneous transmission power, or the data scheduling of the scheduling unit, or by other methods.

Taking the compression mode as an example, in the frequency division duplex (FDD), the UE needs to perform inter-frequency measurement or different-system measurement. Since a transceiver can only work on a set of transmission and reception frequencies at the same time, For signals of other frequencies, the receiver needs to stop working to switch the frequency to the target frequency for measurement. In order to ensure the normal transmission of the signal, the compressed mode is used to transmit the original signal within the remaining transmission time. When a handover is required between the systems, the UTRAN 104 instructs the UE to operate in a compressed mode, which creates an interval by turning off a portion of the transmitted 10ms frame, leaving time for the UE to measure, register, or respond to the page. Compressed mode operation can be achieved by reducing the spreading factor, removing multiple bits (breakdown) from the data, or using advanced scheduling to allocate less time slots to the user traffic. As shown in Fig. 4, in the compressed frame, the length of the transmission interval slot 200 (defined as Nfirst to Nlast slots) is not used for data transmission. The instantaneous transmit power will be increased in the compressed frame to maintain quality during processing gain reduction, such as bit error rate BER, frame error rate FER, and the like. Among them, the increased power value depends on the method used to reduce the transmission time. The higher protocol layer determines the number of frames used in compressed mode. Compressed frames can be set to occur on a regular basis or set to occur on demand. The rate and type of compressed frames can vary, depending on the environment and measurement requirements. Different compressed mode signals can be defined for the uplink and downlink paths and for each mode, radio access technology and frequency band supported by the UE. In a typical application, in compressed mode, the upstream data rate is doubled (using half of the frame), while the downstream data rate is set to more than twice the higher protocol layer.

Example 1

In the embodiment of the present invention, the relationship between the UE and the SFN network and the LTE network is as follows: When the UE receives the MBMS service in the SFN network, the transmission interval slot can be obtained by using the compressed mode or the data scheduling of the scheduling unit. As shown in Fig. 5, in this embodiment, transmission interval slots are obtained in a predetermined cycle. The UE may switch to the LTE network to perform measurement in the transmission interval time slot, and the time and period of the trigger may be determined by the network side. In specific implementation, it may also be triggered by a specific event without a predetermined period, for example, to complete a predetermined operation. The corresponding transmission interval time slot is obtained by scheduling, and then the obtained transmission interval time slot is switched to the LTE network to complete the corresponding operation. For example, the network side may perform operations such as measurement, registration, and the like on the UE in batches according to a grouping method such as a channel, a program, or a certain probability that the UE is receiving.

Example 2:

If the UE is in the mobile and the cell that was originally registered in the LTE network is removed, the UE performs the above measurement to indicate that the UE needs to initiate cell reselection. At this time, the UE switches to the LTE network for cell weight in the corresponding transmission interval slot. Alternatively, the cell reselection operation may be completed in the transmission interval time slot or in the next transmission interval time slot.

Example 3:

If the ΌΈ is in the mobile and the location area originally registered in the LTE network is removed, the result of the above measurement indicates that the UE needs to initiate the location area update. At this time, the UE will switch to the LTE network in the corresponding transmission interval slot. Location area update.

Example 4:

Since the UE receives the MBMS service in the SFN network most of the time, if the UE is in the mobile, it will also perform location area update or cell reselection in the SFN network. At this time, the UE will switch to the corresponding transmission interval slot. The LTE network informs the LTE network of its new cell information in the SFN network.

Example 5

When the UE receives the MBMS service in the SFN network, if there is a paging for the UE in the LTE network, the LTE network may be based on the system information of the UE in the SFN network, such as according to the current location information of the UE. A message is sent to the UE in the SFN network, and the user equipment can respond as needed. After the UE receives the message,

(1) If the page is to be rejected, it may be switched to the LTE network at the corresponding transmission interval slot, a message rejecting the reception is sent, and then the SFN network is returned to continue the reception of the MBMS service;

(2) If it is decided to receive the page in the LTE network, it can be cut in the corresponding transmission interval slot. Switch to the LTE network for service reception;

(3) If you do not wish to respond to the paging message, you can leave no action in the SFN network.

It can be seen from the above embodiments that, in the technical solution provided by the present invention, when the UE receives the MBMS service in the SFN network, it can switch to the LTE network to perform measurement, registration, or response paging in the transmission interval slot. In this way, when a call or paging for the UE is initiated in the LTE network, the network can send the paging notification information to the UE in the SFN network according to the location and cell where the UE is currently located.

The second network in the embodiment of the present invention is an LTE network. In actual applications, the second network may also be other networks than the LTE network, such as a GSM network, a GPRS network, a WCDMA network, a TD network, and the like.

The above embodiments are intended to illustrate and explain the principles of the invention. It is to be understood that the specific embodiments of the present invention are not limited thereto. Various changes and modifications may be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is defined by the claims.

Claims

Rights request

A method for implementing a multimedia broadcast multicast service, where a user equipment receives a multimedia broadcast multicast service in a single frequency network SFN network, and the method includes:

In the process of receiving the multimedia broadcast multicast service, a transmission interval slot is obtained; and the transmission interval slot is switched to a second network outside the SFN network for measurement, registration, or response paging.

2. The method according to claim 1, wherein the transmission interval slot is a transmission gap between two adjacent frames or an idle transmission interval slot in a transmission gap within one frame.

3. Method according to claim 1, characterized in that the switching from the SFN network to the second network is made at a respective transmission interval time slot on a predetermined period or triggered by a predetermined event.

4. The method according to claim 1, further comprising:

According to the result of the measurement performed in the second network, when the multimedia broadcast multicast user equipment needs to perform cell reselection, it switches to the second network for cell reselection in the corresponding transmission interval slot.

The method according to claim 1, wherein, according to the result of the measurement performed in the second network, when the multimedia broadcast multicast user equipment needs to perform location area update, switching in a corresponding transmission interval time slot Go to the second network for location area update.

The method according to claim 1, wherein when the multimedia broadcast multicast user equipment performs cell reselection or location area update in the SFN network, the user equipment switches to the corresponding transmission interval time slot. The second network notifies the second network of the SFN network cell information of the user equipment.

The method according to claim 1, wherein when there is a paging for the multimedia broadcast multicast user equipment in the second network, the second network is based on the multimedia broadcast multicast user System information of the device in the SF network, and sending a message to the user equipment through the SFN network;

The multimedia broadcast multicast user equipment switches to the second network in response to the paging message according to the system information carried in the message in a corresponding transmission interval slot.

8. The method according to claim 7, wherein when the user equipment is at the SFN When the paging message is received in the network,

If the user equipment is to refuse to receive the page, then the corresponding transmission interval slot switches to the second network to send a message rejecting the reception, and then returns to the SFN network to continue receiving the multimedia broadcast multicast service;

If the user equipment is to receive the page, the corresponding transmission interval slot is switched to the second network for receiving the corresponding service.

The method according to claim 1, wherein the network performs the above measurement, registration or response paging in batches according to a packet method of a channel, a program or a certain probability that the UE is receiving.

The method according to any one of claims 1 to 9, wherein the second network is an LTE network, a WCDMA network, a TD network, or a GSM/GPRS network.

A system for implementing a multimedia broadcast multicast service, comprising: a single frequency network SFN, configured to release multimedia broadcast multicast service data;

Receiving, by the user equipment UE, the multimedia broadcast multicast service data in the single frequency network SFN; in the process of receiving the multimedia broadcast multicast data in the SFN network, obtaining an idle transmission interval time slot, where the user equipment is at the corresponding transmission interval The time slot is switched to a wireless communication network outside the SFN network for measurement, registration, or response paging.

The system according to claim 11, wherein the wireless communication network comprises an LTE network, a WCDMA network, a TD network or a GSM/GPRS network.