CN101304560B - Wireless broadcast/multicast system and method - Google Patents

Abstract

The invention discloses a wireless broadcast multicast system and method, the system includes a mobile terminal, a wireless base station, a content distribution center, a broadcast multicast gateway and a broadcast multicast control center, the broadcast multicast control center includes a service configuration module, It is used to determine the resource allocation mode of the service in the cell according to the service information of the content distribution center, and control different resource allocation modes such as single frequency network mode, single cell broadcast or mixed mode resource allocation mode. It has good service continuity, so that terminal equipment can receive broadcast multicast data as well as possible when moving between different types of cells.

Description

A wireless broadcast multicast system and method

technical field

The invention relates to the technical field of wireless communication, in particular to a wireless broadcast multicast (MBMS) system and method.

Background technique

Multimedia Broadcast Multicast Service (MBMS) is a service introduced by the 3rd Generation Mobile Communication Organization (3G Partner Project, 3GPP) after the version Rel6 of its standardized document, which refers to a data source to multiple users The point-to-multipoint service of sending data, so as to realize the sharing of network resources, realize the service to as many multimedia users as possible with the same requirement with as few resources as possible. In the wireless access network part, the multimedia broadcast multicast service can realize the multicast and broadcast of high-speed multimedia services through the use of public transmission channels and public radio bearers.

In the long term evolution project (Long Term Support, LTE) of 3GPP, an enhanced MBMS service, that is, E-MBMS, is proposed, which has the following characteristics: MBMS can use the same carrier of unicast service, and can also use the carrier independently, that is, single frequency Network mode (Single Frequency Network, SFN); in broadcast mode, E-MBMS achieves a spectrum utilization rate of 1 bit/s/Hz at the edge of the cell; E-MBMS basic modulation, coding and multiple access mechanisms and unicast services Same, and can provide MBMS service and unicast service at the same time; single cell broadcast and multi-cell broadcast service can adopt different transmission mechanisms; mobile terminal equipment (Mobile Terminal, MT) can receive MBMS service in both idle mode and connected mode; MBMS transport channel (MBMS point-to-multipoint TrafficCHannel, MTCH) and MBMS control channel (MBMS point-to-multipoint ControlCHannel, MCCH) are defined as the transmission and control channels of MBMS services; for MBMS dedicated cells, uplink data and Counting does not support unicast services.

According to the range of transmission services, E-MBMS is divided into single-cell transmission (non-SFN mode) and multi-cell transmission (SFN mode).

Single Frequency Network (SFN) mode for multi-cell transmission: MBMS services are transmitted in multiple cells, and both MBMS Transport Channel (MTCH) and MBMS Control Channel (MCCH) are carried on a broadcast multicast channel (Multi-Channel, MCH); Support information merging of multiple cells; use point-to-multipoint transmission; use synchronous content transmission.

For the non-single frequency network mode (non-SFN) transmitted by a single cell: the MBMS service is only transmitted in a specific cell; the MBMS service combination of multiple cells is not supported.

The core of multi-cell E-MBMS transmission is single frequency network (SFN) downlink macro-diversity soft combining. The synchronization between the cells is required so that the terminal equipment (MT) can combine the signals of multiple cells. Time Division Multiplexing (Time Division Multiplexing) is adopted. , TDM) or frequency division multiplexing (Frequency Division Multiplexing, FDM) transmission. For Time Division Multiplexing (TDM) and Frequency Division Multiplexing (FDM), the E-MBMS data stream needs to be multiplexed with downlink physical layer and MAC layer signaling. The multiplexing between multiple E-MBMS data streams mainly adopts time division multiplexing to reduce the receiving time of E-MBMS data streams.

However, for E-MBMS, there are still many problems to be solved, including whether to use the feedback mechanism to control MBMS? Which feedback method to use? How to manage the MBMS service of multiple cells dynamically? How to manage the wireless resource allocation of MBMS? How to deal with mobile terminal (MT) mobility issues when receiving MBMS services and so on. Therefore, the prior art cannot dynamically manage the E-MBMS service.

Contents of the invention

The purpose of the present invention is to provide a wireless broadcast multicast system and method, which has good service continuity, so that terminal equipment can receive broadcast multicast data as well as possible when moving between different types of cells.

A kind of wireless broadcast multicast system provided for realizing the object of the present invention, comprises mobile terminal, wireless base station, content distribution center, broadcast multicast gateway and broadcast multicast control center, and described broadcast multicast control center comprises service configuration module , which is used to determine the resource configuration mode of the service in the cell according to the service information of the content distribution center, and different resource configuration modes are used to control different resource configurations.

The resource configuration mode is a single frequency network mode, a single cell broadcast mode, or a single cell mixed mode resource configuration mode.

The service configuration module includes a single frequency network area configuration module, which is used to dynamically configure the resources of all the cells in the multiple cells covered by a single frequency network area during the provision of broadcast and multicast services in the single frequency network mode. manage.

The service configuration module includes a resource allocation module and a storage module, wherein:

The resource allocation module is used to dynamically allocate broadcast and multicast wireless resources according to the information fed back by the terminal feedback module through the feedback channel in the mixed mode of single frequency network and single cell;

The storage module is used for storing location and type information of each broadcast multicast service.

The wireless base station includes a second resource allocation module, configured to allocate wireless resources in the single cell broadcast mode, and notify the broadcast-multicast control center of the operation by sending signaling.

In order to realize the object of the present invention, a method for configuring resources in a wireless broadcast multicast system is also provided, including the following steps:

Step A, according to the service information of the content distribution center, determine the resource configuration mode of the service in the cell, and control different resource configurations by different resource configuration modes.

Described step A comprises the following steps:

Step A1, in the case of sufficient resources, the broadcast and multicast control center configures a service to use the single frequency network mode. In the single frequency network mode, for multiple cells covered by a single frequency network area, the broadcast and multicast service During the provisioning period, the resources of all cells are dynamically managed.

Said step A1 comprises the following steps:

Step A11, when a user joins the broadcast multicast service in a cell adjacent to the single frequency network area, and the resource of the cell is sufficient, add the cell to the single frequency network area to expand the single frequency network area;

Step A12, when a cell in a single frequency network area no longer needs to send broadcast multicast data, the cell no longer uses radio resources for broadcast multicast resources, and the single frequency network area is reduced.

Said step A11 comprises the following steps:

Step A111, when the mobile terminal applies for joining the broadcast and multicast service, if the wireless base station detects that the broadcast and multicast service is not configured in the cell, the wireless base station sends the broadcast and multicast service configuration to the broadcast and multicast control center ask;

Step A112, the broadcast multicast control center detects the dynamic resource allocation of base stations around the wireless base station after receiving the request;

Step A113, if the wireless base station is adjacent to a single frequency network area and the broadcast multicast service has been configured in the single frequency network area, the broadcast multicast control center sends the resource allocation information of the single frequency network to the A wireless base station, the wireless base station performs resource allocation after receiving the information;

Step A114, if the wireless base station allocates the same resources as the single frequency network, then the wireless base station configures resources for the broadcast multicast service, joins the single frequency network area, and then reports the configuration information to the broadcast multicast control center.

Described step A12 comprises the following steps:

Step A121, when the mobile terminal moves to another cell to trigger the cell handover process, if the mobile terminal has been configured with broadcast and multicast services, the wireless base station reports the broadcast and multicast service change of the user to the broadcast and multicast control center during the handover process ;

Step A122, after the broadcast and multicast control center detects the broadcast and multicast service configuration of the target cell of the mobile terminal, if it finds that the target cell is configured with broadcast and multicast control services and the target cell has not joined the single frequency network area, then detect The user's reception of the broadcast multicast service in the wireless base station;

Step A123, if no user in the wireless base station is receiving the broadcast and multicast service, the broadcast and multicast control center notifies the wireless base station to release the resources allocated to the broadcast and multicast service; at the same time, the broadcast and multicast control center modifies the area coverage of the single frequency network Information.

Said step A also includes the following steps:

Step A2, in the case of insufficient resources, the broadcast and multicast control center configures a service to use the mixed mode of single frequency network and single cell broadcast; in the mixed mode of single frequency network and single cell, according to the information fed back by the feedback channel uplink, Dynamic allocation of broadcast and multicast wireless resources, and storage of location and type information of each broadcast and multicast service.

Said step A2 also includes the following steps:

When the mobile terminal is in the connected state, it feeds back its information to the network side through the feedback channel, and the network side controls the switching process to perform cell switching and broadcast multicast services.

The wireless broadcast multicast system resource configuration method also includes the following steps:

Step B, in the single cell broadcast mode, radio resource allocation is performed, and the radio base station sends a signaling to inform the broadcast multicast control center of its operation.

Said step B comprises the following steps:

Step B1, the broadcast multicast control center sends resource configuration information to the radio base station of the cell covered by it for each broadcast multicast service;

Step B2, when the wireless base station receives the broadcast multicast service request from the mobile terminal, it detects its resource configuration. Send resource configuration information, and at the same time, the wireless base station sends the user's service configuration information to the broadcast multicast control center;

Step B3: After receiving the service configuration information sent by the wireless base station, the broadcast and multicast control center saves the service configuration information in this cell, and uses it as a reference for resource allocation of other cells and/or other broadcast and multicast services.

The beneficial effects of the present invention are: the wireless broadcast multicast system and method of the present invention, by setting the functions in each entity in the wireless broadcast multicast system, through the signaling interaction between each entity and the flexible system policy method, can On the premise of providing broadcast and multicast services of different types and different coverage areas, good continuity of broadcast and multicast services is guaranteed, thereby improving the quality of broadcast and multicast services.

Description of drawings

Fig. 1 is a schematic structural diagram of the wireless broadcast multicast system of the present invention;

Fig. 2 is a schematic diagram of the movement of a mobile terminal (MT) within a single frequency network according to the present invention;

Fig. 3 is a schematic diagram of a mobile device moving between a single frequency network and a single cell broadcast;

FIG. 4 is a schematic diagram of movement in a single cell broadcast mode;

Fig. 5 is a flowchart of a mobile single cell broadcast mode of a mobile terminal (MT) in an idle state.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, a wireless broadcast multicast system and method of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

A wireless broadcast multicast system and method of the present invention, for the enhanced wireless broadcast multicast system (E-MBMS) using dynamic service management and single frequency network mode (SFN) technology, through the technical solution provided by the present invention, Good broadcast and multicast service quality assurance can be provided for mobile terminal equipment (MT), so that the equipment can receive broadcast and multicast data as well as possible when moving between different types of cells.

The wireless broadcast multicast system of the present invention is described in detail below, as shown in Figure 1, comprises: mobile terminal (MT) 4, wireless base station (Base Station, BS) 3, broadcast multicast control center (Multicast BroadcastCenter, MBC) 2, Content Distribution Center (Content Delivery Center, CDC) 5, and Broadcast Multicast Gateway (Multicast Broadcast Gateway, MB-GW) 1, wherein:

The mobile terminal (MT) 4 is used to receive wireless data, and assist the wireless base station (BS) 3 to realize mobility through measurement and feedback;

The wireless base station (BS) 3, as the main entity of the wireless air interface, is used for wireless resource management and dynamic unicast wireless resource allocation;

The broadcast multicast gateway (MB-GW) 1, as a connection entity between the core network and the air interface, is used for data distribution, sends broadcast multicast data to a group of cells that have applied for a broadcast multicast service and ensures This process is carried out synchronously among the cells;

The broadcast and multicast control center (MBC) 2, as the main entity in the broadcast and multicast system that supports broadcast and multicast dynamic, flexible and efficient provision of broadcast and multicast services, is used to manage broadcast and multicast resources within different management scopes Dynamic allocation of and handling of service continuity for broadcast-multicast services.

The content distribution center (CDC) 5, as a data distribution entity, is used to provide and issue broadcast-multicast data.

Generally, the transmission of a wireless broadcast multicast service starts from a content distribution center (CDC) 5 . The content distribution center 5 obtains the data source of the broadcast multicast service from the content provider, and then, for each broadcast multicast service that can be provided, notifies the broadcast multicast gateway (MB-GW) 1 to provide the configured initial service area Issue a service available announcement; when the broadcast multicast data is ready, the broadcast multicast gateway (MB-GW) 1 will send session start information to the relevant area; then the corresponding broadcast multicast gateway 1 requests the content distribution center 5 to send The corresponding data source is sent from the content distribution center 5 to the broadcast multicast gateway 1 itself in the form of a standard service; after sending the service notification, the broadcast multicast gateway 1 starts to send synchronously to all associated wireless base stations (BS) 3 Broadcast multicast service data to Terminal 4. These processes are carried out with the assistance and control of the Broadcast Multicast Control Center (MBC) 2 .

A broadcast-multicast service area may include one or more SFN areas, a varying number of cells that use single-cell broadcast, and possibly some cells that do not send service data.

Usually, when wireless resources are sufficient, the entire broadcast multicast service area is configured as the same SFN area, and the same frequency and other data stream configurations are used to send the broadcast multicast service in the entire area.

When radio resources are insufficient to configure an overall SFN area for the entire service, some smaller SFN areas can be configured inside the service area, and at the same time, the single cell broadcast mode is used for those cells that cannot be allocated in SFN mode.

Therefore, resource allocation modes include a single frequency network (SFN) mode, a mixed mode of a single frequency network and a single cell, and a single cell mode.

In the wireless broadcast multicast system of the present invention, in the enhanced wireless broadcast multicast system (E-MBMS), the broadcast multicast control center (MBC) 2 of the present invention includes a service configuration module 21 for Service information determines the resource allocation mode of the service in the cell, and different resource allocation modes control different resource allocation.

The service configuration module 21 of the broadcast and multicast control center 2 determines the resource configuration mode of the service in the cell according to the broadcast and multicast service information (ie service information) transmitted by the content distribution center 5. The service is configured as a single frequency network , single cell broadcast or hybrid mode and other resource configuration methods. The broadcast and multicast control center 2 obtains information such as the range covered by the service and service requirements from the content distribution center 5, and then the resource allocation module 21 of the broadcast and multicast control center 2 checks the resource configuration of each cell saved on the control center, combines The coverage of the service and the bandwidth requirement information determine the resource configuration methods such as single frequency network, single cell broadcast or mixed mode for the service in the cell covered by the service, and different resource configurations are controlled by different configuration methods. Different scenarios, so as to ensure the continuity of the enhanced broadcast multicast service to the greatest extent.

Further, the service configuration module 21 includes an SFN area configuration module 211, which is used to configure the resources of all cells for multiple cells covered by a SFN area during the provision of broadcast and multicast services in the single frequency network mode. Dynamic management.

Furthermore, the service configuration module 21 includes a resource allocation module 212 and a storage module 213 .

The resource allocation module 212 is configured to dynamically allocate broadcast and multicast wireless resources according to the information fed back by the terminal feedback module 41 through the feedback channel uplink in the mixed mode of single frequency network and single cell;

The storage module 213 is configured to store information such as location and type of each broadcast multicast service.

The mobile terminal (MT) 4 includes a feedback module 41, which is used to feed back the information of the mobile terminal to the network end through the feedback channel when the mobile terminal is in the connected state, and the network end controls the handover process to perform cell handover and broadcast Multicast service.

Furthermore, the wireless base station (BS) 3 of the present invention includes a second resource allocation module 31, which is used to allocate wireless resources in the single cell broadcast mode, and notify the broadcast multicast control center (MBC) by sending signaling 2 the operations it does.

Correspondingly, the present invention also provides a wireless broadcast multicast system resource configuration method, including the following steps:

Step S100, according to the service information of the content distribution center, determine the resource configuration mode of the service in the cell, and control different resource configurations according to different resource configuration modes.

The broadcast and multicast control center determines the resource allocation mode of the service in the cell according to the broadcast and multicast service information (that is, service information) transmitted by the content distribution center, and the broadcast and multicast control center obtains the scope and coverage of the service from the content distribution center. Then the multicast control center checks the resource configuration of each cell saved in the control center, combines the service coverage and bandwidth requirement information, and decides to configure the service as a single frequency in the cell covered by the service. Network, single-cell broadcast, or hybrid mode and other resource configuration methods, and different resource configurations are controlled by different configuration methods to form different scenarios, so as to ensure the continuity of the enhanced broadcast multicast service to the greatest extent.

Further, the step S100 includes the following steps:

Step S110, in the single frequency network mode, for multiple cells covered by a SFN area, during the provision of broadcast and multicast services, dynamically manage the resources of all cells;

In the enhanced wireless broadcast multicast system (E-MBMS) using single frequency network mode (SFN) technology, a broadcast multicast service area includes the SFN synchronization area, by using the same frequency between different cells , sending broadcast and multicast services to form a single frequency network (SFN), which can improve spectrum utilization, improve terminal reception quality and eliminate edge effects.

A SFN area can contain two types of cells, one type of cell is a common SFN cell, this type of cell is configured in SFN mode and sends broadcast and multicast data; the other type of cell is a reserved cell, this type of cell Also allocate resources for a broadcast multicast service to this service, the difference is that these resources are not used to bear data, that is, the cell will not send the corresponding broadcast multicast service, and the corresponding resources are reserved to prevent being allocated It causes interference to adjacent SFN cells for other services. Preferably, at a moment, only some of the cells at the edge of the SFN area are configured as reserved cells, so as to save radio resources.

Described dynamic management comprises the following steps:

Step S111, when a cell adjacent to the SFN area has a user joining the broadcast multicast service, and the resource of the cell is sufficient, add the cell to the SFN area to expand the SFN area;

Specifically, the expansion of the single frequency network (SFN) includes the following steps:

When a mobile terminal (MT) applies to join the broadcast multicast service S1, if the wireless base station Cell A detects that the broadcast multicast service S1 is not configured in the cell, the base station sends a broadcast multicast service to the broadcast multicast control center (MBC) service configuration request;

The broadcast multicast control center (MBC) detects the base station dynamic resource allocation around the wireless base station Cell A after receiving the request;

If the wireless base station Cell A is adjacent to a single frequency network (SFN) area and the broadcast multicast service S1 has been configured in the single frequency network (SFN) area, the broadcast multicast control center (MBC) will set the single frequency network (SFN) ) resource allocation information is sent to the wireless base station Cell A, and the wireless base station Cell A performs resource allocation after receiving the information;

If the wireless base station Cell A allocates the same resources as the single frequency network (SFN), the wireless base station CellA configures resources for the broadcast multicast service S1, joins the single frequency network (SFN) area, and then reports the configuration information to the broadcast multicast control center (MBC).

Step S112, when a cell in an SFN area no longer needs to send broadcast multicast data, the cell no longer uses radio resources for broadcast multicast resources, and shrinks the SFN area.

The reduction of the SFN includes the following steps:

When the mobile terminal (MT) moves to other cells to trigger the cell handover process, if the mobile terminal (MT) has been configured with the broadcast multicast service S1, the wireless base station Cell A will report to the broadcast multicast control center (MBC) during the handover process. Report user's broadcast multicast service S1 service change;

After the broadcast and multicast control center (MBC) detects the broadcast and multicast service S1 configuration situation of the mobile terminal (MT) target cell, if it is found that the target cell has configured the broadcast and multicast control center S1 and the target cell has not joined the single frequency network ( SFN) area, then detect the receiving situation of user broadcast multicast service S1 in wireless base station Cell A;

If there is no user in the wireless base station Cell A to receive the broadcast multicast service S1, then the broadcast multicast control center (MBC) notifies the wireless base station Cell A to release the resource allocated to the broadcast multicast service S1; meanwhile, the broadcast multicast control center (MBC) Modification of Single Frequency Network (SFN) area coverage information.

Step S120, in the mixed mode of single frequency network and single cell, according to the information fed back by the terminal feedback module through the feedback channel uplink, dynamically allocate broadcast multicast wireless resources, and store information such as the location and type of each broadcast multicast service ;

At this point, the resource allocation method also includes the following steps:

Step S1201, when the mobile terminal is in the connected state, it feeds back its information uplink to the network side through the feedback channel, and the network side controls the handover process to perform cell handover and broadcast multicast services.

According to the situation of moving between different cells, different wireless resources are selected and allocated to the cells for broadcast and multicast services. For example, when using the static SFN mode, moving the border of the SFN area by the user will cause the broadcast multicast control center (MBC) to allocate a different frequency for the target cell, and provide broadcast multicast service in the single cell broadcast mode in the cell.

In the mixed mode of single frequency network and single cell, the wireless broadcast multicast system uses the carrier to carry data in the air interface part, and the unicast data and broadcast multicast data are sent to the mobile terminal (MT) through the carrier. According to the usage of the carrier, a cell can be divided into a broadcast multicast dedicated cell and a hybrid cell. For broadcast-multicast dedicated cells, all wireless carrier resources are used to send broadcast-multicast data, and there is no unicast service, so there is no uplink channel feedback. The hybrid cell carries broadcast multicast service and unicast data on one carrier at the same time, so the uplink feedback channel can be used.

For the mobile terminal in the connected state, through the uplink feedback mechanism of the feedback channel, the information of the mobile terminal is fed back to the network side through the uplink feedback channel, and the network side controls the handover process to perform cell handover, and the network side can well control the broadcast Behavior of multicast services.

For example, in a possible example, for a user moving to an external cell at the edge of the SFN area, the network side configures the target cell of the user in SFN mode by performing SFN expansion, so that the mobile device can receive the broadcast in the target cell Multicast service and guarantee the continuity of reception.

For a mobile terminal in an idle state, when the target cell is included in the available set of the terminal but the required broadcast multicast service is not provided, the mobile terminal (MT) notifies the network end by sending a broadcast multicast service request, and the network end according to the current The network configuration of the cell and the target cell ensures the continuity of the service. A possible situation is that the network side establishes a connection with the mobile terminal in advance, and then ensures the continuity of the service through the mobile processing mechanism of the connection state.

The broadcast and multicast service request is related to a specific communication system service platform, which is not limited in the present invention. The request is sent as a Non-Access Stratum (NAS) signaling from the Mobile Terminal (MT) to the Broadcast Multicast Control Center (MBC) through the Base Station.

Further, the resource allocation method of the present invention also includes the following steps:

Step S200, in the single cell broadcast mode, perform radio resource allocation, and notify the Broadcast Multicast Control Center (MBC) of the operation by sending signaling.

In some cases, due to the need to send a series of operations such as signaling and scheduling at the same time, it is difficult to ensure the continuity of services through the dynamic allocation of wireless resources by the Broadcast Multicast Control Center (MBC). In the cell broadcast mode, the second resource allocation module of the wireless base station allocates wireless resources, which can greatly reduce the delay of the service in the handover process, and broadcast and multicast in the second resource allocation module of the wireless base station After the service allocates resources, it notifies the MBC of its operations by sending signaling, so that the MBC can still allocate resources globally. The system load and delay time are reduced when user equipment moves between cells in a wireless broadcast multicast system.

The process of allocating radio resources when using the single cell broadcast mode includes the following steps:

Step S210, the broadcast multicast control center (MBC) sends configuration information to the cell base stations covered by it for each broadcast multicast service;

Step S220, when the wireless base station Cell A detects its own resource configuration after receiving the broadcast multicast service request of the mobile terminal (MT), if the wireless base station Cell A is configured as a single cell broadcast mode, then the wireless base station itself provides the broadcast multicast service request for the broadcast multicast service. The broadcast service sends resource configuration information to the mobile terminal (MT), and at the same time sends the user's service configuration information to the broadcast multicast control center (MBC);

In step S230, the broadcast multicast control center (MBC) saves the service configuration information on this cell after receiving the configuration message sent by the wireless base station, and uses it as a reference for resource allocation of other cells and/or other broadcast multicast services.

The wireless broadcast multicast system and its resource configuration method of the present invention will be described below using the resource configuration of an enhanced wireless broadcast multicast system (E-MBMS) during a mobile terminal (MT) movement.

As shown in FIG. 2 , a mobile terminal (MT) is located in a SFN area on which a broadcast multicast service (MBMS) is configured. The mobile terminal (MT) is currently located in cell A and is moving to cell B.

A1. For the case where the mobile terminal (MT) is located in cells A and B, a possible example is that both cells A and B are configured in single frequency network mode (SFN) and are sending broadcast multicast data.

A11) If the mobile terminal (MT) is in an idle state, when the mobile terminal moves to the B cell, use the method of cell reselection to receive the data of the B cell;

A11A) When the mobile terminal (MT) is farther and farther away from the base station of cell A, the signal from cell A that the mobile terminal can receive will gradually weaken.

Use a RAKE receiver or similar technology that can take advantage of the multipath effect on the mobile terminal device to select the one with the same information as the A cell and the largest signal amplitude (in the embodiment of the present invention, cell B) in the available cell set of the mobile terminal. ).

When the amplitude of the signal sent by the wireless base station of cell B exceeds a threshold value Ta, the signal sent by the wireless base station of cell B to the mobile terminal (MT) can be used together with the signal sent by the wireless base station of cell A to the mobile terminal using a RAKE receiver to receive. Since the synchronous transmission protocol is used in the SFN area, the signals transmitted by these two cells can be treated by the wireless terminal (MT) as a multipath situation.

At this time, due to the use of the space diversity technology, the mobile terminal can obtain a better gain, thereby ensuring that the mobile terminal can still normally receive the broadcast multicast service when it is relatively close to the edge of the cell.

The Rake receiver utilizes the concept of space diversity, and the Rake receiver is a standard device type, which is not limited in the present invention.

A11B) As the mobile terminal (MT) approaches cell B, the signal strength difference between the wireless base station of cell A and the wireless base station of cell B sent to the mobile terminal becomes smaller and smaller. When the mobile terminal receives the signal of the wireless base station of cell B After the strength starts to be higher than the signal strength of the radio base station receiving cell A for a period of time t1, the mobile terminal starts the cell reselection process and takes cell B as the result of the cell reselection.

Afterwards, the mobile terminal camps in cell B, and the base station of cell A is still used as a transmission source of a RAKE receiver. At this time, the mobile terminal has successfully moved from cell A to the coverage of cell B.

A11C) If the mobile terminal (MT) is further away from the wireless base station of cell A, so that the signal strength received from the wireless base station of cell A is lower than the threshold Ta, then the mobile terminal no longer receives data from the wireless base station of cell A and sends A Cells are excluded from the currently available set.

The cell reselection is completed jointly by the MT and the base station, and the use of space diversity is performed on the MT, both of which are common processes.

During the moving process of the mobile terminal (MT), the network does not know the location of the mobile terminal, nor does it send signaling information to the mobile terminal, and the mobile terminal can keep receiving broadcast and multicast service data continuously during the moving process.

A12) If the mobile terminal (MT) is in the connected state, or the SFN area carries broadcast multicast service and unicast service at the same time, then the mobile terminal is allocated an uplink channel and establishes a connection, then from cell A to cell B The process of cell movement will trigger the cell handover process, which is similar to the operation in the communication system with only unicast service, and it is consistent with the processing process of the existing unicast service system such as WCDMA, except that the multicast Service information exchange. The information sent during this process and the load and delay generated by operations such as allocating unicast channels will not affect the reception of broadcast-multicast data by the mobile terminal (MT).

Another possible example of A2, mobile terminal (MT) moving inside the SFN area is that the B cell is located at the edge of the SFN area, so it may be a reserved cell; the broadcast multicast service carried by the SFN area on the reserved cell Radio resources are not used to transmit data. In this case, the mobile terminal (MT) is in the process of moving to cell B, and the cell B belongs to an available set of the mobile terminal.

A21) For the system using static SFN management, when the mobile terminal (MT) gradually moves away from cell A and moves towards cell B, the broadcast multicast service signal that the mobile terminal (MT) can receive becomes weaker and weaker.

A21A) When the signal strength received by the mobile terminal (MT) from cell A is lower than a threshold Tb, the mobile terminal will send a service request to the base station of cell A, the service request includes the identification number of cell B and the required broadcast Multicast service ID.

A21B) The base station in cell A forwards the request to the broadcast and multicast control center (MBC), and the broadcast and multicast control center configures cell B into a single-cell broadcast mode for sending the broadcast and multicast service, and then performs the request for cell B. Dynamic resource allocation.

The following process description can be used:

Cell A uses RRC layer signaling to send a broadcast multicast service configuration request to the MBC;

MBC receives the request;

If(MBC calculates that the cell cannot join the SFN area)

then

MBC sends cell configuration information to Cell A base station through RRC signaling;

The Cell A base station configures the service to use the single cell broadcast mode;

Endif

While (MT sends the broadcast multicast service request through RRC message)

then

The Cell A base station will jointly schedule the service and the unicast service;

Cell A sends the scheduling result to MT through physical layer signaling;

end

A21C) Thereafter, the wireless base station in cell B will join the broadcast multicast service group, and realize the synchronous sending of broadcast multicast data in cell A and cell B through the synchronous sending protocol.

A21D) Cell B will send paging information to notify all mobile terminals (MT) in the cell to start receiving broadcast multicast services after completing the synchronous transmission, and the mobile terminals will switch and reside in cell B. At the same time, the mobile terminals will receive The signal is switched to the resource and modulation mode used by cell B.

After the mobile terminal finishes switching, it starts to receive data using the broadcast multicast service provided by the cell B.

Preferably, the threshold Tb is set high enough, and the threshold Tb is higher than the minimum value at which the mobile terminal can correctly receive data, so that the mobile terminal can still receive the signal of the cell A when switching to use the service of the cell B, Avoid service discontinuities.

A22) For the system using dynamic SFN management, similar to the static management system, when the mobile terminal (MT) moves to cell B and the signal strength received from A is lower than the threshold Tb, the mobile terminal will move to cell A A radio base station sends a service request, which is forwarded to a Broadcast Multicast Control Center (MBC) for processing.

The difference is that the broadcast and multicast control center (MBC) does not need to allocate specific wireless resources for cell B, but uses the reserved wireless resources in cell B to configure the wireless base station in cell B to SFN mode, and at the same time, broadcast multicast The control center (MBC) sets the cells outside the SFN area adjacent to cell B to the SFN mode through the dynamic SFN management strategy and uses them as reserved cells.

Since cell B is configured as SFN mode, the mobile terminal (MT) does not need to switch frequency resources, but uses the cell reselection operation to camp in cell B, that is, the ordinary cell reselection process, which is not limited in the present invention.

As shown in FIG. 3 , a schematic diagram of a mobile terminal (MT) moving between cells in an SFN area and a non-SFN area. The following are divided into two directions of movement:

B1. The mobile terminal moves from the edge of an SFN area to a cell in a non-SFN area.

B11) A possible situation is that border cell A in the SFN area is sending broadcast multicast service data, while cell B outside the SFN area is also carrying the same broadcast multicast service on other resources.

B11A) If the mobile terminal (MT) is in the connected state in the cell A, the mobile terminal will send a measurement report to the wireless base station during the movement of the cell B in the mobile terminal. When the base station finds that the signal that the mobile terminal can receive is constantly weakening, it will Trigger the cell handover process.

Through a common cell handover procedure, a mobile terminal (MT) is handed over from cell A to cell B, and switches the reception of the broadcast multicast service from the resources on the radio base station in cell A to the corresponding frequency of the radio base station in cell B.

B12B) If the mobile terminal (MT) is in an idle state in cell A, before performing cell handover, the mobile terminal finds that the signal of the wireless base station of cell B gradually becomes stronger in its own available set, but in the current wireless resource, the cell The wireless base station of B does not transmit the expected broadcast multicast service data. Therefore, when the signal strength received by the mobile terminal from the radio base station of cell A decreases to a threshold Tc, the mobile terminal (MT) will send a connection establishment request to the radio base station of cell A.

The radio base station in cell A starts to establish a connection between the mobile terminal and the network, so that the mobile terminal transitions from the idle state to the connected state.

Then, since the measurement signal received by the base station of cell A from the mobile terminal continues to weaken, the radio base station of cell A decides to perform a cell handover and handovers the mobile terminal from cell A to cell B through the general handover procedure.

Since the mobile terminal has switched from the idle state to the connected state in advance, it can continuously receive broadcast multicast data between cells using different frequencies through a handover process.

Preferably, the value of the threshold Tc is slightly larger than the threshold used by the wireless base station of the cell A to start to determine the handover of the mobile terminal.

B2. Another possible situation is that the cell A in the SFN area is sending a broadcast multicast service, but the cell B to which the mobile terminal (MT) is moving does not carry the service.

If the mobile terminal (MT) is in the connected state, the mobile terminal will send a measurement report to the base station of cell A during the movement of the mobile terminal. The wireless base station of cell A can learn that these base stations carry broadcast multicast services by exchanging information with the surrounding base stations. Condition. When the wireless base station of cell A detects the measurement report fed back by the mobile terminal (MT), once it finds that the mobile terminal receives the broadcast multicast service quality of this cell is lower than a threshold Td, the wireless base station of cell A sends broadcast multicast The control center (MBC) sends service request signaling. The broadcast multicast control center immediately allocates resources for the service and sends the allocation result to the radio base station of cell B. At the same time, the wireless base station in cell B configures the newly allocated resources into a single-cell broadcast mode, and then joins the corresponding broadcast and multicast group. After that, the wireless base station in cell B starts to send broadcast and multicast services through the synchronization protocol with the network. , while the radio base station in cell B starts to bear the broadcast multicast service, the mobile terminal will start the handover process controlled by the network, from cell A to cell B. Since the wireless base station in cell B has been configured before the handover and starts to send broadcast multicast service data, the mobile terminal can continuously receive broadcast multicast data during the movement from cell A to cell B.

B3. The mobile terminal moves from a cell using single cell broadcasting to a cell using single frequency network (SFN).

B31) If the mobile terminal (MT) is in the connected state, the mobile terminal will trigger handover to cell A during the moving process.

Since the broadcast and multicast service has been carried in the SFN area, when the wireless base station of cell B decides to start handover, the information about the broadcast and multicast service carried by the wireless base station of cell A can be learned through the interface with base station A. When the wireless base station of cell B finds that the two cells carry the same service but use different wireless resources, the wireless base station of cell B will notify the mobile terminal (MT) of The broadcast multicast reception switches to the resources used by the single frequency network mode (SFN). Therefore, as long as the unicast data of the mobile terminal can be continuously received between the two cells, the switching requirement for the broadcast multicast service can also be completed on the mobile terminal at the same time.

B32) If the mobile terminal (MT) is in an idle state, before performing cell handover, the mobile terminal finds that the signal of the wireless base station of cell A gradually becomes stronger in its own available set but the wireless base station of cell A does not have any signal on the current wireless resource Send desired broadcast multicast service data. Therefore, when the signal strength received by the mobile terminal (MT) from the radio base station of cell B drops to a threshold Tc, the mobile terminal will send a connection establishment request to the radio base station of cell B. The radio base station of cell B starts to establish a connection for the mobile terminal, so that the mobile terminal transitions from the idle state to the connected state.

Then, because the measurement signal received by the wireless base station of cell B from the mobile terminal continues to weaken, the wireless base station of cell B decides to perform handover of the mobile terminal, and the mobile terminal is handed over from cell B to cell A through a common handover procedure.

After the mobile terminal is handed over correctly, the mobile terminal can receive broadcast multicast data from the cell A.

After a time t2, if the mobile terminal does not actually have any unicast service to be processed, in order to save resources, the radio base station of cell A switches the mobile terminal to an idle state. Afterwards, as long as the mobile terminal is still moving in the SFN area, the mobile terminal can be in an idle state, and at this time, the continuity of the mobile terminal receiving broadcast and multicast services can be guaranteed.

As shown in Figure 4, when the mobile terminal moves between two cells that do not use the single frequency network mode (SFN), the processing of the situation is the same as that shown in Figure 3, and at this time a cell is regarded as An SFN area containing only one cell. In this case, continuity of broadcast-multicast service reception can be guaranteed.

As shown in FIG. 5 , it is a signaling flowchart of a mobile terminal (MT) in an idle state moving from cell A to cell B.

Generally speaking, if a mobile terminal (MT) is in a connected state, it triggers a handover process when it moves between cells, and a large part of the corresponding broadcast and multicast signaling is reused in the handover signaling, which can reduce signaling overhead.

The invention sets the conversion process of the unicast data and the conversion of the broadcast multicast service data at the same time when switching, so that after the mobile terminal (MT) switch is completed, both the unicast and broadcast multicast service resources have been switched to the new cell. Here, the radio base station of cell A is transmitting a broadcast multicast service, while the radio base station of cell B is not carrying the service. At the same time, it is assumed that during the process of the service request, the broadcast multicast control center (MBC) decides to configure the cell B in a single-cell broadcast mode to bear the broadcast multicast service.

Step 1. When the mobile terminal (MT) moves from cell A to cell B, because the quality of the received broadcast multicast service deteriorates, and the mobile terminal finds that it is moving away from cell A through measurement, the mobile terminal (MT) passes the uplink The channel sends a service request to the wireless base station of cell A, which contains the required broadcast multicast service identifier and the target cell;

Step 2, the wireless base station of cell A forwards the service request to the broadcast multicast control center;

Step 3, since the broadcast and multicast control center saves the distribution of broadcast and multicast services, the broadcast and multicast control center can make a decision on how to configure and allocate resources to cell B, and then return the result of the decision to The wireless base station of cell A; at the same time, the broadcast multicast control center (MBC) and the wireless base station of cell B start to configure the broadcast multicast service;

Step 4, the wireless base station of cell B is configured according to the scheduling result of the broadcast multicast control center (MBC), that is, when Cell B is scheduling, the resource allocation of the broadcast multicast service is strictly matched with the result given by MBC ; At the same time, the wireless base station of cell B joins the multicast group of the broadcast multicast service, and the wireless base station of cell B starts to provide the broadcast multicast service to the cell after receiving the confirmation information;

Step 5, while the wireless base station of cell B is running, the wireless base station of cell A receives the service decision, and controls the mobile terminal (MT) to switch from the idle state to the connected state,

The description of the original text of the present invention is specific to two situations, one is the mobility management when the MT is in the idle state, and the other is the mobility management when the MT is in the connected state, and the transition between the two states is not included in the scope of the invention Within the range of MT, all mobility actions are set based on the current state of the MT;

Step 6, after the mobile terminal (MT) switches to the connected state, it starts to send a measurement report to the wireless base station of cell A;

Step 7, the wireless base station of cell A initiates the handover process in a timely manner according to the measurement report, that is, when the MT detects that the signal quality of the current serving cell is below a certain threshold Sho; the wireless base station of cell A and the wireless network of cell B Signaling interaction is performed between the base stations to obtain resources for unicast and broadcast multicast services prepared by mobile terminals in cell B;

Step 8, the radio base station of cell A sends switching signaling to the mobile terminal (MT) according to the obtained information, informing the mobile terminal (MT) to switch both unicast and broadcast multicast services to the new channel configuration.

The process is described as follows:

Cell B initiates the scheduling process to allocate channels for the MT's service

Cell B sends the scheduling result to cell A through RRC signaling

Cell A forwards the scheduled signaling to MT through RRC message

MT prepares to use a new channel in its own data link layer scheduling and channel multiplexing process;

Step 9, the mobile terminal (MT) receives the handover signaling, starts to convert its own data receiving configuration, and starts to perform data synchronization with cell B;

Step 10, after the data synchronization is completed, the mobile terminal sends a handover completion signaling to the wireless base station of cell B;

Thereafter, the mobile terminal camps on cell B and no longer receives data from A;

In step 11, the base station of cell B notifies the wireless base station of cell A to release the connection resources of the mobile terminal after learning that the mobile terminal has completed the handover, and deletes the mobile terminal from the members of the multicast group of cell A.

The wireless broadcast multicast system and method of the present invention, in the enhanced wireless broadcast multicast system (E-MBMS), uses the single frequency network mode to improve the utilization rate of wireless resources, when the mobile terminal moves in different types of cells It can better guarantee the continuity of the broadcast multicast service and make full use of the advantages of the single frequency network, improve the utilization rate of wireless resources of the system and reduce the number of signaling used for the broadcast multicast service.

Other aspects and features of the present invention will be apparent to those skilled in the art by describing specific embodiments of the present invention in conjunction with the accompanying drawings.

The specific embodiments of the present invention have been described and illustrated above, and these embodiments should be considered as exemplary only, and are not used to limit the present invention, and the present invention should be interpreted according to the appended claims.

Claims (10)

1. a wireless broadcast/multicast system comprises portable terminal, the wireless base station, content Distribution Center, broadcast multi-broadcasting gateway and broadcast multi-broadcasting control centre is characterized in that, be applicable to the wireless broadcast multicast service of enhancing, described broadcast multi-broadcasting control centre comprises the service configuration module;

Described service configuration module comprises the single-frequency network area configuration module, is used under the single frequency network pattern, and a plurality of sub-districts to a single-frequency network area covers are providing the broadcast multi-broadcasting viability, and the resource of whole sub-districts is carried out dynamic management;

Described service configuration module comprises resource distribution module and memory module, wherein:

Described resource distribution module is used under single frequency network and single sub-district mixed mode, according to the information of the up feedback of feedback channel, to the dynamic assignment of the Radio Resource of broadcast multi-broadcasting;

Described memory module is used to store position, the type information of each broadcast multi-broadcasting service;

Wherein, broadcast multi-broadcasting control centre obtains scope and the demand for services that a service covers from content Distribution Center, by checking the resource distribution situation of each sub-district of preserving in the broadcast multi-broadcasting control centre, coverage and bandwidth demand in conjunction with this service, determine the resources employment methods of this service on the sub-district that this service covers, and control different resource distributions by different configuration modes:

Under the situation of resource abundance, broadcast multi-broadcasting control centre becomes to use the single frequency network mode with a service configuration; Under the situation of inadequate resource, broadcast multi-broadcasting control centre becomes to use single frequency network and single Cell Broadcast CB hybrid mode with a service configuration.

2. wireless broadcast/multicast system according to claim 1 is characterized in that, described resources employment methods is single frequency network pattern or single Cell-Broadcast mode or single sub-district mixed mode resources employment methods.

3. wireless broadcast/multicast system according to claim 1 and 2 is characterized in that, described wireless base station, comprise second resource distribution module, be used under single Cell-Broadcast mode, carrying out allocation of radio resources, and by sending its operation done of the described broadcast multi-broadcasting of signaling control centre.

4. a wireless broadcast/multicast system resource allocation method is characterized in that, is applicable to the wireless broadcast multicast service of enhancing, and described method comprises the following steps:

Steps A, broadcast multi-broadcasting control centre obtains scope and the demand for services that a service covers from content Distribution Center, by checking the resource distribution situation of each sub-district of preserving in the broadcast multi-broadcasting control centre, coverage and bandwidth demand in conjunction with this service, determine the resources employment methods of this service on the sub-district that this service covers, and by the different different resource distributions of configuration mode control; Described steps A comprises the following steps:

Steps A 1, under the situation of resource abundance, broadcast multi-broadcasting control centre becomes to use the single frequency network mode with a service configuration, under the single frequency network pattern, to a plurality of sub-districts that a single-frequency network area covers, during the broadcast multi-broadcasting service provides, the resource of whole sub-districts is carried out dynamic management;

Steps A 2, under the situation of inadequate resource, broadcast multi-broadcasting control centre becomes to use single frequency network and single Cell Broadcast CB hybrid mode with a service configuration; Under single frequency network and single sub-district mixed mode,,, and store position, the type information of each broadcast multi-broadcasting service to the dynamic assignment of the Radio Resource of broadcast multi-broadcasting according to the information of the up feedback of feedback channel.

5. wireless broadcast/multicast system resource allocation method according to claim 4 is characterized in that, described steps A 1 comprises the following steps:

Steps A 11 adds the broadcast multi-broadcasting service when there is the user sub-district of single-frequency network area adjacency, and the resource of this sub-district adds single-frequency network area with this sub-district when enough, carries out the expansion of single-frequency network area;

Steps A 12, when the sub-district in the single-frequency network area no longer needed to send the broadcast multi-broadcasting data, Radio Resource was no longer used for the broadcast multi-broadcasting resource in this sub-district, carries out the reduction of single-frequency network area.

6. wireless broadcast/multicast system resource allocation method according to claim 5 is characterized in that, described steps A 11 comprises the following steps:

Steps A 111 when the portable terminal application adds the broadcast multi-broadcasting service, does not dispose in this sub-district if the wireless base station detects the broadcast multi-broadcasting service, and then described wireless base station sends the request of broadcast multi-broadcasting service configuration to broadcast multi-broadcasting control centre;

Steps A 112, described broadcast multi-broadcasting control centre receives that this request back detects the base station Dynamic Resource Allocation for Multimedia around described wireless base station;

Steps A 113, if described wireless base station and single-frequency network area are adjacent and this single-frequency network area has been configured the broadcast multi-broadcasting service, then described broadcast multi-broadcasting control centre sends to this wireless base station with the resource allocation information of this single frequency network, and this wireless base station carries out resource distribution after receiving information;

Steps A 114, if distribute the resource identical with single frequency network in this wireless base station, then this wireless base station is a broadcast multi-broadcasting service configuration resource, and the adding single-frequency network area, then configuration information is reported to described broadcast multi-broadcasting control centre.

7. wireless broadcast/multicast system resource allocation method according to claim 5 is characterized in that, described steps A 12 comprises the following steps:

When steps A 121, portable terminal moved the triggering cell handoff procedure to other sub-districts, if this portable terminal has been configured the broadcast multi-broadcasting service, then user's broadcast multi-broadcasting service change was reported in the wireless base station to broadcast multi-broadcasting control centre in the process of switching;

Steps A 122, this broadcast multi-broadcasting control centre is after detecting the broadcast multi-broadcasting service configuration situation of portable terminal Target cell, if find that Target cell has disposed broadcast multi-broadcasting control service and Target cell does not add described single-frequency network area, then detect the reception condition of user's broadcast multi-broadcasting service in the wireless base station;

Steps A 123 if there is not the user receiving the broadcast multi-broadcasting service in the wireless base station, then will be distributed to the resource release of broadcast multi-broadcasting service by broadcast multi-broadcasting control centre notice wireless base station; Simultaneously, the information that single-frequency network area covers is revised by broadcast multi-broadcasting control centre.

8. wireless broadcast/multicast system resource allocation method according to claim 4 is characterized in that, described steps A 2 also comprises the following steps:

Portable terminal by the up network terminal that feeds back to of feedback channel, carries out its information the sub-district by network terminal control handoff procedure and switches when being in connection status, and the broadcast multi-broadcasting service.

9. wireless broadcast/multicast system resource allocation method according to claim 4 is characterized in that, also comprises the following steps:

Step B under single Cell-Broadcast mode, carries out allocation of radio resources, and the wireless base station is by sending its operation done of signaling broadcast multi-broadcasting control centre.

10. wireless broadcast/multicast system resource allocation method according to claim 9 is characterized in that described step B comprises the following steps:

Step B1, broadcast multi-broadcasting control centre sends resource allocation information for each broadcast multi-broadcasting service to the wireless base station of the sub-district of its covering;

Step B2, detect its other resources configuration receive the broadcast multi-broadcasting service request of portable terminal when this wireless base station after, if this wireless base station is configured to single Cell-Broadcast mode, then send resource allocation information by the wireless base station from serving to portable terminal as this broadcast multi-broadcasting, this wireless base station sends to broadcast multi-broadcasting control centre with this user's service configuration information simultaneously;

Step B3, broadcast multi-broadcasting control centre are kept at this service configuration information on this sub-district after receiving the service configuration information that this wireless base station sends, and as the reference of other sub-districts and/or other broadcast multi-broadcasting service resource allocation.

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