WO2009024068A1

WO2009024068A1 - The method for determining the time of sending data, the method, device and system for multicast blocking

Info

Publication number: WO2009024068A1
Application number: PCT/CN2008/072000
Authority: WO
Inventors: Jie Ma
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-08-15
Filing date: 2008-08-15
Publication date: 2009-02-26
Also published as: CN101370175B; CN101370175A

Abstract

The method for determining the time of sending data includes the following steps: the data source determines the optimum time window to send the data packet based on the first time and the last time in which the transmitter must receive the data packet, and selects the sending time point in the optimum time window. The method for multicast blocking, the device for determining the time of sending data, the device for multicast blocking, the device for multicasting are disclosed at the same time. Therefore the probability about the data packet would reach the transmitters synchronously can be improved, then each transmitter can send data packet synchronously.

Description

Method for determining data transmission time, multicast grouping method, device and system

Technical field

The present invention relates to the field of communications, and more particularly to techniques for determining the time at which data is transmitted.

Background technique

With the rapid development of the Internet, a large amount of mobile multimedia service data has emerged. Some of these mobile multimedia service data require multiple users to receive the same data at the same time, such as video on demand, TV broadcast, video conferencing, online education, interactive games, and so on.

The Third Generation Mobile Communications Global Standards Organization (3GPP) proposes a Multimedia Broadcast Multicast Service (MBMS) technology for mobile communication networks, which can provide a data source to multicast and broadcast service data to multiple users. Point-to-multipoint services, which include not only plain text low-rate messaging services, but also high-speed multimedia services, which undoubtedly conform to the trend of business data development.

In the MBMS technology, in order to enable the UE (terminal equipment) side to better receive services, a technique of air interface merging is used on the UE side. Correspondingly, it is required to support air interface merging on the network side, which requires that the same coding mode is used when multiple MBMS services are transmitted by multiple cells, and strict air interface synchronization is transmitted; the UE side receives the same service with different power sizes from neighboring cells. After the signal, the UE side regards the signals of these different cells as different multipath components of one signal, performs air interface combining by RAKE (multipath diversity) receiver, and regards the combined signal as a signal input decoder. Thereby, the signal-to-noise ratio (SNR) of the input decoder signal is relatively large compared to when only the signal of the own cell is considered.

In order to achieve simultaneous transmission of MBMS data packets at the IP multicast layer, the prior art typically utilizes timestamps to meet the requirements for synchronous transmission. The timestamp sent by the air interface ^ ^ The time when the station sends the data packet from the air interface. It can be a certain exact time or a frame number. However, each base station that requires air interface merging must have the same definition and arrangement of the frame number.

Prior Art One provides an E-HSPA (Evolved High Speed Data Access) network based on Figure 1 The implementation of the MBMS service architecture, using timestamps to achieve synchronous transmission of MBMS services, as follows:

After the GGSN (Gateway GPRS Support Node) or the SGSN (Serving GPRS Support Node) receives the MBMS service data delivered by the BM-SC (Program Source), the GGSN/ Or the SGSN gateway is used as a data source, and the MBMS service data packet is sent to the IP router (multicast router), and the air interface sending time stamp is specified in the MBMS service data;

The IP router copies and distributes the MBMS service data packets to each eHSPANodeB according to the multicast tree. Each eHSPA NodeB acts as a data termination sender, and after processing the received MBMS service data packets, finally transmits the data of the own cell in the air. In order to realize that MBMS service data can be combined when receiving on the UE side, each data termination sender synchronously transmits MBMS service data according to the timestamp on the data packet.

The prior art 2 provides an IP multicast architecture for implementing an MBMS service in an HSPA+ network as shown in FIG. 2, and a method for synchronously transmitting an MBMS service by using a timestamp, as follows:

Before the start of the MBMS service, the core network represented by the SGSN (or GGSN) first determines one or more Master e-NodeB+s (primary base stations) within the service transmission range, and other e-NodeB+s as Slave e-NodeB+s (slave base stations); The IP multicast address is sent to the IP Router and each Slave e-NodeB+ through the control plane process;

As the data source, the master e-NodeB+ receives the MBMS service data from the core network, and after the layer processing, determines the transmission timestamp of each data block, and sends the MBMS service data;

The MBMS service data is copied and distributed to each Slave e-NodeB+ through the IP Router;

Each Slave e-NodeB+ is used as a data termination sender, and the received MBMS service data is sent out through the physical layer at the time corresponding to the timestamp. Thereby, the MBMS service data is merged when it is received by the UE side.

The prior art 3 provides an IP multicast architecture based on the implementation of the MBMS service in the S AE/LTE network as shown in FIG. 3, and uses the timestamp to implement the method for synchronously transmitting the MBMS service, as follows: After receiving the MBMS data packet sent by the BM-SC, the MBMS GW determines the final air interface transmission timestamp as the data source, and sends the MBMS data packet at the timestamp;

MBMS packets are distributed to each eNodeB through IP Router replication;

Each eNodeB acts as a data termination sender, using the allocated resources (in this architecture, the MCE (MBMS Control Entity) is responsible for the resource allocation and coordination process of each eNodeB), and the MBMS data packet is sent at the specified time.

It can be seen from the above prior art that when the MBMS service data packet arrives at the data termination sender, it is copied and distributed by the multicast router, which reduces the transmission load from the data source to the data termination sender, but The path of the multicast router to each sender of the data is different. Therefore, the time when the data packet arrives at the sender of each data cannot be guaranteed. If the arrival time is too early, the data packet will be stored in the data termination sender for too long. It is possible. Causing a buffer overflow; if the arrival time is too late, the data termination sender will not have enough time to process and send, so there is no guarantee that multiple data termination senders will send out the received data packets synchronously, and thus the data packets are not sent. Synchronous transmission causes the user to fail to merge the received data.

Summary of the invention

Embodiments of the present invention provide a method of determining a transmission time, a multicast packet method, a transmission time determining apparatus, a multicast packet apparatus, and a multicast system, which enable a plurality of data terminating senders to synchronously transmit a data packet.

Embodiments of the present invention are implemented by the following technical solutions:

Embodiments of the present invention provide a method for determining a data transmission time, including:

Determining an optimal time window for the data source to send the data packet according to the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet according to the plurality of data belonging to the same multicast packet;

The transmission time is selected in the optimal time window.

An embodiment of the present invention further provides a multicast grouping method, including:

The earliest transmission time corresponding to the time window in which the sender must receive the data packet according to multiple data terminations And the latest transmission time, determining that the plurality of data terminates the multicast packet to which the sender belongs. An embodiment of the present invention further provides a data sending time determining apparatus, including:

An optimal time window determining unit, configured to determine, according to a plurality of data belonging to the same multicast packet, an earliest sending time and a latest sending time corresponding to a time window in which the sender must receive the data packet, and determining the data source sending the data packet Best time window;

a sending time determining unit, configured to select a sending time in the optimal time window.

An embodiment of the present invention further provides a multicast grouping apparatus, including:

An obtaining unit, configured to acquire a plurality of data terminations, an earliest sending time and a latest sending time corresponding to a time window in which the sender must receive the data packet;

And a grouping unit, configured to perform multicast grouping on the plurality of data termination senders according to an earliest transmission time and a latest transmission time corresponding to a time window in which the sender must receive the data packet according to the plurality of data terminations.

The embodiment of the present invention further provides a multicast system, including a data source and a plurality of data termination senders, where the data source sends a data packet to the data termination sender, where the data source includes: a time determining device, configured to determine, according to a plurality of data belonging to the same multicast packet, an earliest sending time and a latest sending time corresponding to a time window in which the sender must receive the data packet, determining an optimal data packet sending data packet Time window; select the sending time of the data packet in the optimal time window.

It can be seen from the specific implementation provided by the foregoing embodiment of the present invention that the data source determines the maximum transmission time of the data packet according to the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet. Good time window; select the sending time in the best time window. The probability that a data packet transmitted based on the transmission time arrives at a plurality of data to terminate the sender at the same time is improved, so that each data termination sender can synchronously transmit the data packet.

DRAWINGS

1 is an architecture diagram of implementing an MBMS service in an E-HSPA network provided by the prior art; FIG. 2 is an IP multicast architecture for implementing an MBMS service in an HSPA+ network provided by the prior art 2. FIG. The IP multicast architecture of MBMS in SAE/LTE provided by Technology 3; 4 is a process of setting a cache amount according to an embodiment of the present invention;

Figure 5 is a flow chart of the first embodiment of the present invention;

6 is a schematic diagram of time parameters involved in a sender from a data source to a data termination in the first embodiment of the present invention;

FIG. 7 is a flowchart of obtaining an IP path transmission time by a data source according to a first embodiment of the present invention; FIG. 8 is a flowchart of a data termination sender acquiring an IP path transmission time according to the first embodiment of the present invention; The reporting process of the number m of data waiting to be processed in the cache in an embodiment; FIG. 10 is a reporting process of the time window in the first embodiment of the present invention;

FIG. 11 is a schematic diagram of an algorithm for determining an actual transmission time window of a data source according to the first embodiment of the present invention; FIG. 12 is a flow chart of a time adjustment notification according to the first embodiment of the present invention;

13 is a schematic diagram of a multicast grouping of an SGSN before a service starts in a second case in the first embodiment of the present invention;

14 is a schematic diagram of re-dividing a multicast packet in a second case in the first embodiment of the present invention; FIG. 15 is a schematic diagram of a multicast architecture in a fifth case in the first embodiment of the present invention;

Figure 16 is a schematic view showing the structure of a third embodiment of the present invention.

detailed description

Because in the process of multicast sending MBMS service data, the difference in transmission speed of each link will cause some data to arrive early and some data to arrive late. Data arriving early must wait until the sending time arrives; the data arriving late cannot meet the sending requirements of the air interface, so the data source is required to be sent early or resent. Therefore, it is inevitable to require a certain amount of cache on the sender side of the data to buffer the transmission speed when the data is transmitted.

Considering that a data termination sender will run many business data at the same time and the data terminates the sender's physical memory is limited, so you need to set a maximum cache number and the most d, the number of caches for each multicast service before transmitting the service data.

The minimum number of caches should be able to satisfy the jitter of its own link; the maximum number of caches can be set according to the amount of physical memory. The minimum amount of cache set for a multicast service can be calculated according to Equation 1:

Size _t = V _air * Si Equation 1 The transmission rate of the air interface in Equation 1; the difference between the maximum time and the shortest time of the data source to the data-terminated sender link transmission unit number.

Since a link with a faster average speed stores a certain amount of data in a unit time than a link with a slower average speed, it is necessary to set a certain amount of cache for the above multicast service on a link with a fast average speed. The number of caches is as shown in Equation 2:

ASize = AV _t Equation 2 where represents the difference between the average speeds of the two links.

Therefore, in the maximum jitter period, the maximum number of buffers per unit time set for the above multicast service is as shown in Equation 3:

The process of setting the number of caches in Equation 3 is shown in Figure 4, including:

The data source sends a Buffer set Indication message, which carries one or more of the following parameters: the minimum number of caches, the maximum number of caches, and the average number of caches.

When sending the above message, it can be based on one or more of the following transmission policies:

1) When the event command needs to be adjusted or set for the first time;

2) periodic setting;

3) According to the specified number of cache thresholds.

The data termination sender sets the corresponding cache amount according to the parameters carried in the message.

The above method is also applicable to the multicast router to the data termination sender. At this time, the multicast router, such as the IP router, can send a corresponding indication message to the data termination sender as a data source.

The above method is also applicable to the data source to the multicast router (such as the IP Router). At this time, the multicast router can determine the corresponding data termination according to the corresponding indication message sent by the data source and the route of the multicast router to the data termination sender. The sender's cache count. After the above buffer quantity is set, each data termination sender uses the cache quantity to buffer the received service data, so that the received service data can be synchronously transmitted.

After an MBMS service decides to start using multicast transmission, the data source needs to determine the transmission time of the data packet that is sent by itself, so that multiple data termination senders belonging to the same multicast packet can receive the multicast data, so that Multiple data termination senders simultaneously deliver the service data they receive. To this end, the first embodiment of the present invention provides a method for determining a data transmission time. The specific implementation process of the method is as shown in FIG. 5, and includes the following steps:

Step S101: The data source acquires an earliest sending time and a latest sending time corresponding to a time window in which the data packet of the same multicast packet belongs to the same multicast packet that the sender must receive the data packet.

In the implementation of step S101, the following two methods can be used:

In the first method, the data source may first acquire a time parameter involved in transmitting the data packet from the data source to the data termination sender, and then calculate, according to the time parameter, a time window in which each data termination sender must receive the data packet. Corresponding earliest sending time and latest sending time.

In the second method, each data termination sender obtains a time parameter involved in transmitting a data packet from the data source to the data termination sender, and then calculates, according to the time parameter, a time at which each data termination sender must receive the data packet. The earliest sending time and the latest sending time corresponding to the window, and the calculated earliest sending time and the latest sending time are sent to the data source.

In the above two methods, the time parameters involved in the data source to the data termination sender are shown in Figure 6. As can be seen, these time parameters include:

The IP path transmission time r _t from the data source to the data termination sender (the maximum value is the dish and the minimum value is Γ Min );

The data terminates the sender's air interface transmission time T;

The data packet is processed at the sender's processing time Γ _ρ ;

The data packet is buffered at the sender's buffer time; (the maximum value is _⁄3⁄4Μ4 and the minimum value is T _bMm , and the delay offset is 7 due to the difference in the merge mode; _fei (the terminal needs to combine the received data packets) And processing, the merge mode can use air interface merge, soft merge or selective merge. Each combination mode is different for the time synchronization accuracy of transmitting data packets in the air interface or the deviation of the transmission time with respect to the specified time, so the difference of the combining mode leads to the delay offset 7; ^).

Use 2 to indicate the earliest transmission time corresponding to the time window in which the data packet must be received by the sender. 2, as shown in Equation 4:

Ts = T _air ― T Max - T p - T b max + ^offset Equation 4

Use ; to indicate the latest transmission time corresponding to the time window in which the data packet sender must receive the data packet; as shown in Equation 5:

TL = T _air - T _tMIN - Τ _ρ + _βί Equation 5

Corresponding to the first method described above, the acquisition of the IP path transmission time r _t (the maximum value is the dish and the minimum value is T _Mm ) can be seen in FIG. 7 , including:

The data source sends an IP roundtrip time request message, and the parameters carried in the message are: time when the message is sent 2;

After receiving the above message, the data termination sender returns an IP roundtrip time response (IP loopback time response) message, which carries the following parameters: time T ₂ when the IP roundtrip time request message is received; time _{3 of the} IP roundtrip time response ;

After receiving the IP roundtrip time response, the data source calculates the IP simplex transmission time 7 according to the Τ ₂ and ₃ time parameters carried in the time and the time when the message is received; as shown in Equation 6:

Τ _χ = Τ _Α - Τ^ Τ ₂ - Τ _χ ) Ι 2 Formula 6

Considering that IP transmission has jitter, IP simplex transmission time; the determination often cannot be based on the results of one measurement and calculation, but is determined according to a certain strategy:

1) Perform multiple measurement and detection processes in multiple time periods, then average the values in each segment, and then process the measured values of each segment to obtain the maximum, minimum and average values in all time periods. Value

2) Perform multiple measurement and detection processes in multiple time periods and in each segment, taking the maximum value of each segment or Minimum value; then the measured values of each segment are processed to obtain the maximum, minimum and average values over all time periods.

In order to reduce the load brought to the link by the measurement process, the measurement process of determining the IP simplex transmission time T _t can also be performed according to a certain strategy. These strategies include:

1) After measuring for a period of time, it is found that the transmission time is distributed in a very narrow interval (for example, the range of the interval is less than 1 millisecond), the measurement can be stopped, and the periodic measurement phase is specified.

2) When there are data packets on the link for interaction, the transmission time of the data packet is monitored instead of the transmission time measurement.

3) Only some links are measured, these links have the longest or shortest transmission time or these links are particularly busy or determined based on past experience.

4) Select the timing of the measurements so that the timing of the measurements is performed according to a certain distribution, which also reduces the link load and the system burden of processing these measurements.

Corresponding to the second method of implementing the foregoing step S101, the acquisition of the IP path transmission time r _t (the maximum value is the dish and the minimum value „) can be referred to FIG. 8 and includes:

The data termination sender sends an IP roundtrip time request message, and the parameters carried in the message are: time 2 of sending the message;

After receiving the message source data, message returned IP roundtrip time response, which carries the following parameters: receiving IP roundtrip time request message transmission time T ₂ IP roundtrip time response time T _3;

After the data termination sender receives the IP roundtrip time response, according to the Τ ₂ and ₃ time parameters carried in it and the time when the message is received, the IP simplex transmission time j ₌ (7 -WJ is still calculated using Equation 6) ;)/2.

Also considering that IP transmission has jitter, the data termination sender determines the IP simplex transmission time according to a certain strategy; The specific strategy is similar to the above description, and will not be described in detail here.

Corresponding to the first method of implementing the foregoing step S101, the buffer time of the foregoing data packet (the maximum value is The minimum value and the minimum value of U can be estimated based on experience, or a reasonable value can be set according to the actual service transmission requirement, or can be calculated by the following method:

Considering the minimum cache time is related to the following two factors:

1. The amount of data in the cache that has been processed for processing m;

2. The processing time of each packet is Γ _ρ . So the minimum buffer time of the packet can be calculated using Equation 7:

m

TbMin = Σ ^ _{P i} Equation 7 When each packet processing time is the same, the minimum buffer time can be calculated using Equation 8:

TbMin = m " T _p Equation 8 The maximum buffer time for a packet is related to several factors:

1, the amount of data in the cache that has been waiting to be processed m;

2. The processing time of each data packet Γ _ρ ;

3. The maximum deviation of the transmission time of the transmission link;

4. The maximum deviation of the transmission time of this transmission link and other transmission links in multicast.

So the maximum buffer time of the packet can be calculated using Equation 9:

T _bMAX = S + Ae + ∑ T _Pi Equation 9 where, when m is the maximum number of buffers max^S z calculated by Equation 3, the maximum buffer time can be obtained by Equation 9.

The number m of data already waiting to be processed in the buffers in Equation 7, Equation 8, and Equation 9 above can be obtained by the following two ways:

The first way is when the data source sends data, records the amount of data sent and the required sending time. By comparing the sending time of the already sent data with the current time, the number of data waiting to be processed in the sender's buffer can be obtained. m ;

The second way is the data termination sender reports how much data is still waiting to be processed, the data source root According to the report, the data is obtained to terminate the number m of data waiting to be processed in the sender buffer. The reporting process of the number m of data waiting to be processed in the specific cache is as shown in FIG. 9, and includes:

The data source sends a Buffer report Request message to the data termination sender, and the request data terminates the sender for the cache usage report. The message carries: the reporting policy; the usage of the cache number (that is, the amount of data waiting to be processed in the cache) m) and so on.

The reporting policy includes any one or more of the following:

1) Report according to the event order;

2) Periodic reporting, this method is generally applicable to the case where the data terminates the sender's smooth operation;

3) Reporting according to the specified threshold value: for example, when the buffer idle amount is sharply reduced to 50% of the original value; or, when the cache idle amount is increased to twice the original value, the report is performed;

4) reporting a partial data terminator belonging to the same multicast packet;

5) When the multicast packet is established, the notification data is terminated by the sender.

The cached unit of measure can be a number, such as 5 blocks of cache; the cached unit of measure can also be a number of bytes, such as 1 Mbyte.

After the data termination sender receives the Buffer report Request message, it responds according to the specified reporting method. Buffer report Response.

For the second and third types of reporting methods, the data termination sender will report it periodically or when the conditions are met. In these cases, there will be multiple "Buffer report Response" in Figure 9.

The maximum deviation δ of the transmission link itself in the above formula 8 and the maximum deviation of the transmission time between the transmission links can be obtained by measuring the transmission time of the IP path.

Corresponding to the second method of implementing the above-mentioned step S101, in the buffering time η of the data packet, the number of data waiting to be processed in the buffer involved in the calculation process of the maximum value and the minimum value U, the data termination sender can The situation of the self is determined, so the processing flow of obtaining the number m of data waiting to be processed in the cache in the first method is no longer needed, and the other descriptions are similar to those in the first method, and will not be described in detail here.

Corresponding to the first method of implementing step S101 above, when the data source acquires each data termination sender The "time window reporting" process is required when the earliest sending time and the latest sending time corresponding to the time window of the data packet must be received, as shown in FIG. 10, including:

The data source sends a time window report request message, and the request data terminates the sender's time window report. The message carries: the report policy; the time window for requesting the report.

The escalation strategy can be any one or more of the following:

1) Report according to the event order;

2) Periodic reporting, this method is usually applied to the case where the data terminates the sender's smooth operation; 3) Report according to the specified threshold: For example, when the starting value of the time window is reduced by 50%, report it. Or, when the latest time of the time window increases to twice the original value, it is reported;

4) reporting a partial data terminator belonging to the same multicast packet;

After receiving the message, the data termination sender returns a Time window report Response message according to the specified report mode. For the second and third types of reporting methods, the data termination sender will report it periodically or when the condition is met. In these cases, there will be multiple "time window report Response" in Figure 10.

The unit of the reported time window can be milliseconds, subtle, chip, connection frame number;

The value of the reported time window may be the earliest transmission time and the latest transmission time calculated according to Equation 4 and Equation 5; or may be the earliest transmission time corresponding to the time window obtained by reducing the time window based on the calculated time window. And the latest transmission time (the earliest transmission time is later than the calculated earliest transmission time, and the latest transmission time is earlier than the calculated latest transmission time). When the time window is reduced, it can be performed according to the distribution of IP transmission time jitter, for example When the distribution of the IP transmission time jitter conforms to the normal distribution, the amount that needs to be reduced is the variance of the jitter, so that the processing can effectively handle the burst on the transmission path.

The initiation of the time window may be based on other policies, for example, when the multicast group is established, the notification data is terminated by the sender to actively report the time window.

Step S102: The data source calculates, according to each data, an earliest sending time and a last sending time corresponding to a time window in which the sender must receive the data packet, and calculates an optimal time window for sending the data packet by the data source. The data source terminates the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet according to each data calculated by Equation 4 and Equation 5, and calculates the most data packet actually transmitted by the data source according to Formula 10. Good time window:

T send (leg T _Si , mm T _Li . Equation 10 In Equation 10, n is the number of data-terminated senders; _{m ax} f is the terminator for each data.

S / ' must receive the maximum value of the earliest transmission time corresponding to the time window of the packet; _{m in} f- ¹ is the end of each data

The sender of the Li must receive the minimum of the latest transmission time corresponding to the time window of the packet.

It can be seen from Equation 10 that the optimal time window for the data source to actually send the data packet is the intersection of multiple data termination senders that must receive the data packet.

Taking the data source as the master e-NodeB and the data termination sender as Slave e-NodeB1 to Slave e-NodeB4 as an example, the algorithm determines the actual transmission time window algorithm of the data source, as shown in FIG. It can be seen that as the data termination sender Slave e-NodeB1 must receive the data packet time window (T _sl , T _Ll ); as the data termination sender Slave e-NodeB2 must receive the data packet time window ( , T _L2 ) ; as the data termination sender Slave e-NodeB3 must receive the data packet time window ( _s3 , T _L3 ) ; as the data termination sender Slave e-NodeB4 must receive the data packet time window ( _s4 , T _L4 ). As the data source, the Master e-NodeB must ensure that each data termination sender must receive the data packet, and then consider the time window in which each data termination sender must receive the data packet, and each data termination sender must receive the data packet. The maximum value of the earliest transmission time of the time window: r _S4 , the minimum value of the latest transmission time of the time window in which the data packet must be received by the sender, as the best time to send the data packet as the data source window.

In step S103, the data source determines the calculated 7 . ₆ is empty set if not, proceed to step S104; if so, it means that the data source found it impossible to find time to meet all of the data window of the sender's end, so to step S105. Step S104: Select one time from the sending optimal time window to send the data packet. The data source transmits the data packet at any time within the transmission optimal time window shown in FIG. 11, and the data termination sender can finally perform the air interface transmission at the time specified by the time stamp.

Step S105, the data source uses a method of re-sending the sender of each data to adjust the sending time, or adjusts the sending time by using the method of resetting the data to terminate the sender's buffer, or adjusting the sending time; or sending the data according to the point-to-point The method of the packet, adjusting the sending time of the sender for one data termination.

When performing multicast grouping, the data terminating sender corresponding to the time window having the intersection is divided into one multicast packet, and the time window in which the sender must receive the data packet is terminated according to the data belonging to the same multicast packet. Corresponding earliest sending time and latest sending time, determining an optimal time window for the data source to send the data packet; selecting the sending time in the optimal time window.

An example of re-mapping a multicast packet is as follows:

First, the intersection of these time windows is searched again based on the earliest transmission time and the latest transmission time corresponding to the time window of the sender. If the time window of one data termination sender and the time window of the other two data termination senders respectively intersect, but there is no intersection between the time windows of the other two data termination senders, then the one with the largest time intersection is selected as a group. . By analogy, there is finally one data to terminate the sender to find a common time window 1; one data termination sender found a common time window 2;

The data source sets up a multicast group with the data of the common time window 1 to terminate the sender, and sets a data group with the common time window 2 to terminate the sender to form a multicast group;

The data source notifies the sender that the sender re-divides the multicast group and notifies the group address; the data termination sender rejoins the multicast group, and the data is re-transmitted.

Before performing the foregoing multicast grouping, the method further determines whether the number of data terminating senders corresponding to the time window having the intersection exceeds a set threshold, and when the determined result is exceeded, performing the multicast grouping process; If it is not exceeded, if the number of data termination senders corresponding to a time window with an intersection is less than a certain threshold (for example, less than 3), the data source no longer establishes a multicast group for them. Instead, according to the method of sending data packets point-to-point, adjust the sending time of sending data packets from the data source to a data termination sender.

If the process of re-dividing a multicast group occurs in the service transmission process, the data source maintains the continuity of the service. The process of re-dividing the multicast group learns the peer-to-peer transmission mode for each data termination sender.

When the method of adjusting the transmission time by resetting the data to terminate the sender's buffer is used to adjust the maximum buffer size of the multicast service, the maximum number of buffers of a multicast service can be calculated by Equation 1 to Equation 3, and then adjusted according to the adjustment. The maximum number of caches afterwards and the time parameters involved in transmitting data packets from the data source to the data termination sender, determining the earliest transmission time and the latest transmission time corresponding to the time window in which each data termination sender must receive the data packet, and Each data terminates the intersection of the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet, as the best time window for the data source to send the data packet, and then selects any within the optimal time window. One time as the sending time.

After the data source sends the data packet based on the selected transmission time, the data termination sender receives the data packet sent by the data source. When the data termination sender finds that the data packet arrives too late, the data source is notified to perform the transmission time adjustment. The specific time adjustment notification process is shown in Figure 12, including:

The data source selects a time to transmit within the calculated time window. Due to the abnormal condition of the burst on the transmission path, the data termination sender receives a burst of late packets, and the data terminates the sender. A "Time Adjustment Indication" message is reported, which carries: the difference between the late arrival packet and the latest arrival time considered by the data termination sender.

After the data source is received, an appropriate amount of time adjustment is performed according to the difference between the late arrival packet and the latest arrival time that the data terminates the sender, so as to ensure that all data termination senders are in their own time window. Received a packet. For example: According to the data termination sender, the late packet is 3 milliseconds later than the data termination sender thinks the latest arrival time, the data source advances the packet transmission time by 3 milliseconds.

When the data termination sender repeatedly discovers that the data packet arrives later than the latest transmission time of the time window, Then, according to the method in the above step S101, the calculation and reporting of the earliest transmission time and the latest transmission time corresponding to the time window are re-executed.

After the data source receives the time adjustment indication message of the same data termination sender multiple times in succession, the data source should recalculate the time window corresponding to the time window of the sender and other data termination senders according to the method in step S101 above. The earliest send time and the latest send time, and then according to the formula

10 Determine the final best time window for transmission.

In the foregoing first embodiment, the first transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet may be determined in advance according to the plurality of data terminations, and the group to which the plurality of data termination senders belong is determined. The broadcast packet is divided into a multicast packet by the data termination sender corresponding to the time window having the intersection. Then the processes of steps S101 to S105 are performed.

The foregoing data source may be an SGSN, a GGSN, or an MBMS gateway, or the like; or an evolved base station, or an RNC, or a multicast router.

The above data termination sender may be a base station, an evolved base station, a multicast router, or an RNC. The implementation of the first embodiment of the present invention will be described in detail below in several cases:

The first case:

A total of three e-NodeBs in an SFN (Single Frequency Network) need to receive MBMS services, and send time for the air interface of the e-NodeB, which is set to 11:5:55:45, and e-NodeB 1 is merged due to air interface. The delay offset caused by the mechanism is T. _Ffset = 0.1 milliseconds, the delay offset of e-NodeB2 due to air interface merging and other mechanisms is T. _Ffsen =0.05 milliseconds, the delay offset caused by the mechanism of e-NodeB3 due to air interface merging is ₃ = 0.1 milliseconds, each e-NodeB has 100 buffers, and e _ρ1 = 0.2 milliseconds of e-NodeBl, e-NodeB2 Γ _ρ2 = 0.3 ms, e-NodeB3 Γ _ρ3 = 0.1 ms, and IP transmission time is _tl = 25 ms, _t2 = 30 ms, _t3 = 40 ms.

According to the above time parameters, formula 4 and formula 5, each e-NodeB can obtain the earliest transmission time and the latest transmission time corresponding to the time window in which the data packet must be received, as follows:

e-NodeB 1 : T _S1 = T _air ― T _n ― T _pl

T _n =T _air -T _n -T _pl +T _offsetl = 11 points 5 minutes 55 seconds 19.9 milliseconds e-NodeB2:

T, ₂ = T _air ― T _t2 ― T _p2 — (TV-1) * T _p2 + T _{offset 2} = 11 points 5 minutes 54 seconds 993.15 milliseconds T _L2 =T _air -T _t2 -T _p2 +T _offset2 = 11 Point 5 minutes 55 seconds 14.75 milliseconds e-NodeB3: 3 = T _air ― Γ, ₃ ― Τ _ρ3 — — 1) * Τ _ρ3 + T _offset 3 = 11 points 5 minutes 54 seconds 995.1 milliseconds T _L , =T _air -T _Ti -Τ _ρ3 +Τ _φββ = 11:5:55:5 milliseconds Each e-NodeB will calculate 7 each; and report it to SGSN/GGSN, SGSN/GGSN can easily get the best time window according to formula 10:

3 3

τ [11 points 5 minutes 55 seconds 0.1 milliseconds, 11 points 5 minutes 55 seconds 5 milliseconds: I face ' ^min

i=\ i=\

Of course, each of the e-NodeB T _p may be reported to other time parameters SGSN / GGSN gateway,

Based on these time parameters, the SGSN/GGSN gateway uses Equation 4 and Equation 5 to calculate the earliest transmission time and the latest transmission time corresponding to the time window in which each e-NodeB must receive the data packet, and then obtain the most transmission using Equation 10. Good time window.

The second case:

MBMS service 1 is to be sent in HSPA+ network P in soft combining mode. Network P has one master node, such as Master e-NodeB+1, 3 slave nodes, such as Slave e-NodeB+2, Slave e-NodeB+3. , Slave e-NodeB+4. Before the service starts to be sent, the master node sends a "time window Request" message to the three slave nodes respectively. The message indicates that the upper 4艮 mode is: 1) Firstly, 4 time window is immediately applied; then, the short cycle report is performed. The short period is 0.25 milliseconds; 2) After 5 minutes of measurement, it is found that the change of the earliest transmission time and the latest transmission time of the time window is less than 5%, and it is transferred to the long period (500 milliseconds) for reporting. It also stipulates that "IP roundtrip time Request" is not sent for IP transmission when there is actually sending a packet. Time monitoring, the simplex transmission time can be obtained only through the data packet; the time window of the transmission should have a margin of 6% (meaning: the earliest transmission time reported is later than the actual transmission time, the latest transmission time ratio Take the time early).

Slave e-NodeB+2 After measuring the IP transmission time, using Equation 4 and Equation 5, the earliest transmission time corresponding to the time window in which the packet can be correctly processed is 150 milliseconds earlier than the air interface transmission time, and the latest transmission time is The air interface transmission time is 75 milliseconds ahead.

Slave e-NodeB+3 After measuring the IP transmission time, using Equation 4 and Equation 5, the earliest transmission time corresponding to the time window in which the packet can be correctly processed is 152 milliseconds earlier than the air interface transmission time, and the latest transmission time is The air interface transmission time is 70 milliseconds ahead.

Slave e-NodeB+4 After measuring the IP transmission time, using Equation 4 and Equation 5, the earliest transmission time corresponding to the time window in which the packet can be correctly processed is 140 milliseconds earlier than the air interface transmission time, and the latest transmission time is The air interface transmission time is 85 milliseconds ahead.

Slave e-NodeB+2, Slave e-NodeB+3, Slave e-NodeB+4 use the message "time window report Indication" to calculate the earliest transmission time and the latest transmission time.

After receiving the report from each slave node, the master node calculates its own best time window for sending according to formula 10: {140, 80}. The master node randomly selects a value between the two points 140 and 80 for the data packet to be sent.

Within 5 minutes after the start of the service, the three slave nodes report the time window according to the short cycle. After 5 minutes, each slave node finds that the time window requested by the slave node has not changed, so it is transferred to the time window of the longer cycle, that is, 500. In milliseconds, ^ time window.

After the service runs for a period of time, the Slave e-NodeB+3 has a sudden change in the traffic of the user within the coverage of the cell, so that the processing load of the Slave e-NodeB+3 itself reaches 80% of its full load capacity. The processing speed of Slave e-NodeB+3 is slightly decreased and the number of caches is greatly reduced. Therefore, the time window required by it changes, and the earliest transmission time is 100 milliseconds earlier than the air interface transmission time. The latest transmission time is the air interface. The sending time is 80ms in advance. When the value calculated by Slave e-NodeB+3 continuously in 200 milliseconds changes, although the period of reporting the transmission time window is not reached, Slave The e-NodeB+3 is still on the transmit time window and automatically transitions to a short period of time. The master node receives the time window after Slave e-NodeB+3, and adjusts the transmission window [100, 80]. Then select the sending time to send the data packet in the new sending time window.

The third case:

In an MBMS HSPA+ network, the SGSN sends the MBMS service 1 and 50 neighboring e-NodeBs receive the service. Therefore, the SGSN decides to deliver the data packet in multicast mode, and the SGSN will use the 50 before the service starts. e-NodeB+ is set to a multicast packet (shown in Figure 13). The SGSN specifies in the session control flow the time synchronization method for sending packets:

a) Each e-NodeB+ reports its own buffering and processing time and the reporting time is as follows: Starting from a certain time A, with + ₆ ^ 0 (168 + serial number 1110 (125 milliseconds (this can prevent the SGSN from receiving the reported data) Peak).

b) The transmission time is measured by the SGSN, and finally the transmission time of each e-NodeB+ is obtained.

Before the data is sent, the SGSN sends the message "IP roundtrip time Request" to each e-NodeB+. This message is sent by multicast through the multicast router. It can also be sent in one-to-one mode, that is, SGSN. Sent separately to each e-NodeB+. The message carries the time T1 at which the SGSN sends the message. After receiving this message, each e-NodeB+ first records the time T2 when it receives the message, then generates the response message "IP roundtrip time Response", and records the time of the time when it is ready to send Τ3, and finally the message The parameters carried are Τ2 and T3. The SGSN receives the response message of each e-NodeB+, and records the arrival time as T4. Therefore, the transmission time of the IP path of the SGSN to the e-NodeB+ is calculated by Equation 6.

At the same time, each e-NodeB+ also reports the number of caches that can be used and the maximum processing time of the data (or the average processing time or the minimum processing time) according to the specified time.

Based on the obtained parameters of each e-NodeB+, the SGSN calculates the earliest transmission time and the latest transmission time corresponding to the time window of each e-NodeB+ by using Equation 4 and Equation 5.

The SGSN calculates the earliest transmission time corresponding to the time window of each e-NodeB+ according to the above calculation. At the latest transmission time, using Equation 10, the common time window of the above 50 e-NodeB+s is calculated, that is, the transmission optimal time window is determined, and a transmission time is selected within the optimal time window for data transmission.

In order to avoid excessive measurement of the IP transmission time for the transmission link and the processing capacity of the SGSN, the SGSN starts to monitor the IP transmission time when transmitting the data packet. If the IP transmission time is found during a period of monitoring, Very stable, and the length of the distribution is less than the length of the common time window. It is considered that the current time window is not adjusted, and the frequency of monitoring can be reduced. For example, it is monitored once every 100 milliseconds. It is found that after 5 minutes of smooth operation, it is changed to 2 Monitor once in seconds.

During the service transmission process, the e-NodeB+'s own cache idle rate is reduced to 40%, and the cached quantity is reported. After receiving the cache report, the SGSN determines whether to recalculate the transmission time window and adjust the transmission time according to the number and distribution of the report. For example: Suppose only 2 e-NodeB+s report their own cache number reduced to 40%. The SGSN thinks that the number of abnormal e-NodeB+s is only 4%, and does not receive the message from these two e-NodeB+ request time adjustments. (The time-adjusted message indicates that the data was sent too early or late), so it was decided not to recalculate the time window and not adjust the transmission time.

After the service has been sent for a period of time, the SGSN finds that the range of transmission times of many e-NodeB+s varies greatly according to the monitored transmission time, so it is decided to initiate the IP transmission time measurement process of all e-NodeB+s. After the above measurement process is finished, the calculation of the time window shows that the time window of 10 e-NodeB+s has an intersection of 1, and the time windows of the other 20 e-NodeB+s have an intersection 2, and the time windows of the other 20 e-NodeB+s. There is an intersection of 3. Therefore, the SGSN changes the multicast group and sends a session update message to all e-NodeB+s to notify them of the changes of their respective multicast groups, as shown in Figure 14. The new three multicast groups then resume the transmission of data.

The fourth situation:

The network environment of the fourth case is the same as the network environment of the third case, but the data flow is from the GGSN through the multicast router to each e-NodeB+, and the SGSN has only session control function. Therefore, the process of calculating the optimal time window for transmitting, adjusting the IP transmission time, the buffering time, and the processing time to be reported is performed between the GGSN and the e-NodeB+, and all the process messages are controlled by the user plane. Framed to carry. The adjustment method, monitoring method, and reporting strategy in this case can be referred to the third case. The fifth case: In the multicast architecture under the MBMS HSPA+ network as shown in Figure 15, the time window is changed after the reporting method and the condition change, and the above is again performed.

As shown in Figure 15, the master node is the traditional Master RNC (master radio network controller) and the slave node is e-NodeB+. The MBMS service combines air interfaces in this network to form an SFN. Before the start of the service, the earliest sending time and the latest sending time corresponding to the time window of each slave node e-NodeB+ are calculated by the master node itself; the relevant transmission time parameters and the available buffer number and processing time are required for each reporting, The reporting method is to perform the measurement process of "IP transmission time" for 1 minute, then stop the measurement, use the accompanying measurement of the data packet in the process of transmitting the data packet, and the accompanying measurement is only for the shortest IP transmission time (e-NodeB) +1) and the two nodes of the longest IP transmission time (e-NodeB+4).

During the transmission of the SFN service, the e-NodeB+3 continuously reports 10 packets of time delay due to interference, so the e-NodeB+3 continuously reports 10 "time adjustment indications" to the traditional Master RNC. The traditional RNC adjusts the transmission time at the beginning of reception and starts monitoring the transmission time of the data packet. When the "time adjustment indication" of the e-NodeB+3 is received 10 times in succession, the reception path of the e-NodeB+3 is considered to be a problem. Therefore, at this time, the e-NodeB+3 is first required to no longer receive the data packet through the multicast address or process, and instead uses the separate transmission to enable the service to continue the SFN integration within the e-NodeB+3 coverage. Then the IP transmission time measurement is performed, and the multicast router is also required to perform the transmission time measurement between it and the e-NodeB+3. After measuring for 30 seconds, by comparing the data of other nodes and the current measurement, it is found that the multicast router arrives. The e-NodeB3+ has been taking too long.

The traditional Master RNC notifies the multicast router to re-route the e-NodeB+3 route to achieve the purpose of re-transmitting the multicast, and starts the timing monitoring of the transmission time to the e-NodeB+3. The multicast router re-updates the routing table after the routing calculation result, and re-defines the priority of the data sent to the e-NodeB+3.

After a period of detection, the traditional Master RNC finds that the IP transmission time from Master RNC to e-NodeB+3 has been between the maximum transmission time and the minimum transmission time for 30 consecutive seconds. Therefore, The legacy Master RNC notifies the e-NodeB+3 to the multicast group, and re-uses the multicast mode to send data to the e-NodeB+3. The e-NodeB+3 exit and join the multicast group can be notified by the control plane and can also be notified through the control plane of the user plane.

Sixth situation:

In the sixth case, the multicast architecture and the required adjustment method are basically the same as the fifth case. After the service is sent for a period of time, 90% of the time adjustment indication messages are continuously reported from the e-NodeB+, so the traditional RNC of the master node thinks that the timestamp needs to be changed at this time to meet the transmission requirements. Therefore, the traditional RNC adjusts the timestamp, increasing the timestamp interval of every two adjacent data packets to be able to perform multicast transmission and satisfying service characteristics and combining requirements.

The second embodiment of the present invention further provides a multicast grouping method, which determines that the plurality of data ends according to an earliest sending time and a latest sending time corresponding to a time window in which a plurality of data ends a sender must receive a data packet. The multicast packet to which the sender belongs, that is, the data terminator corresponding to the time window having the intersection is divided into one multicast packet.

The multicast grouping method may further determine whether the number of data termination senders corresponding to the time window of the intersection exceeds a set threshold. When the determination result is exceeded, the foregoing multicast grouping process is performed; when the determination result is not exceeded When the number of data termination senders corresponding to a time window with an intersection is less than a certain threshold (for example, less than 3), the data source no longer establishes a multicast group for them.

Thereafter, for a plurality of data termination senders belonging to the same multicast packet, the data source can use the method of the first embodiment of the present invention to determine the optimal time of the data packet from the data source to the plurality of data termination senders. Window, and selecting a sending moment to send a data packet from the optimal time window. For these data termination senders that do not have multicast packets, the data source determines the transmission time from the data source to the data sender to the sender based on the point-to-point method of sending the data packet.

Corresponding to the first embodiment of the present invention, a third embodiment of the present invention provides a data transmission time determining apparatus, which has a structure as shown in FIG. 16, and includes: an optimal time window determining unit 161 and a transmission time determining unit 162.

The optimal time window determining unit 161 is configured to use a plurality of data belonging to the same multicast packet. Terminating the sender to receive the earliest transmission time and the latest transmission time corresponding to the time window of the data packet, and determining the optimal time window for the data source to send the data packet;

The sending time determining unit 162 is configured to select a sending time in the optimal time window. The optimal time window determining unit 161 may further include:

The optimal time window determining sub-unit is configured to use the intersection of the earliest sending time and the latest sending time corresponding to the time window that the sender must receive the data packet, and the best time window for sending the data packet as the data source .

The data transmission time determining apparatus may further include:

a grouping unit, configured to determine, according to a plurality of data terminations, an earliest transmission time and a latest transmission time corresponding to a time window in which the sender must receive the data packet, and determine the multicast packet to which the plurality of data terminates the sender. For example, the grouping unit divides a plurality of data terminators corresponding to the time window of the intersection into the same multicast packet. Or, the grouping unit determines whether the number of data termination senders corresponding to the time window having the intersection exceeds a set threshold, and if so, divides the plurality of data termination senders corresponding to the time window having the intersection into the same multicast group. in.

The data transmission time determining apparatus may further include:

a calculating unit, configured to acquire a time parameter involved in transmitting a data packet from the data source to the data termination sender, and calculate, according to the time parameter, an earliest sending time corresponding to a time window in which the data end sender must receive the data packet And the latest transmission time; the calculation result is supplied to the above-described optimal time window determining unit 161. The specific processing is similar to the related description in the first embodiment, and will not be described in detail herein. Or,

An obtaining unit, configured to terminate a sender's report information according to the data, and obtain an earliest sending time and a latest sending time corresponding to a time window in which the sender must receive the data packet, where the earliest sending time and the latest sending time are The data termination sender calculates the time parameter involved in transmitting the data packet from the data source to the data termination sender, or the earliest transmission time and the most calculated by the data termination sender according to the time parameter. The earliest transmission time and the latest transmission time obtained after the reduction is based on the late transmission time. Provide the obtained data to the above best time The window determining unit 161. The specific processing situation is similar to the related description in the first embodiment, and will not be described in detail herein.

The data transmission time determining apparatus may further include:

a detecting unit, configured to determine whether an intersection of an earliest sending time and a latest sending time corresponding to a time window in which the data end sender must receive the data packet is empty;

a time adjustment unit, configured to adjust a transmission time when the detecting unit detects that the intersection is empty. The time adjustment unit may further include:

a first time adjustment subunit, configured to: according to each data, a time window corresponding to a transmission time at which the sender must receive the data packet, obtain a data sender having an intersection of the time window; and determine a data termination sender corresponding to the intersection window Divided into a multicast packet, and according to the data belonging to the same multicast packet, the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet, determine the most data packet transmission data packet. a good time window; the transmission time is selected in the optimal time window; the specific processing situation is similar to the related description in the first embodiment, and will not be described in detail herein. Or,

a second time adjustment subunit, configured to: according to each data, the time window corresponding to the sending time that the sender must receive the data packet, obtain the data sender with the intersection of the time window; determine the data end corresponding to the time window with the intersection When the number of senders does not exceed the set threshold, the transmission time of the data packet from the data source to the data termination sender is adjusted according to the method of transmitting the data packet by point-to-point; the specific processing is similar to the related description in the first embodiment, It will not be described in detail here. Or,

The third time adjustment sub-unit is configured to adjust the maximum buffer quantity of the multicast service, and determine, according to the adjusted maximum number of buffers and the time parameter involved in transmitting the data packet from the data source to the data termination sender, The earliest transmission time and the latest transmission time corresponding to the time window of the received data packet, and each data terminates the intersection of the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet as data. The optimal time window for the source to send the data packet; the specific processing situation is similar to the related description in the first embodiment, and will not be described in detail herein. or, The fourth time adjustment subunit is configured to adjust a sending time of the data packet from the data source to a data termination sender according to the method of sending the data packet in a point-to-point manner. The specific processing situation is similar to the related description in the first embodiment, and will not be described in detail herein.

The data transmission time determining apparatus may further include:

The adjusting unit is configured to adjust the sending time according to the difference between the time when the data packet arrives at the end of the data packet and the latest sending time corresponding to the time window in which the data terminal must receive the data packet.

The adjusting unit may further include:

a first adjusting subunit, configured to reselect a sending time in the optimal time window; or, a second adjusting subunit, configured to send, according to the data, the earliest sending corresponding to the time window that the sender must receive the data packet The time and the latest sending time, re-determine the best time window for sending the data packet, and select the sending time in the best time window. The specific processing is similar to the related description in the first embodiment, and will not be described in detail herein.

Corresponding to the second embodiment of the present invention, a fourth embodiment of the present invention provides a multicast grouping apparatus, including:

The grouping unit may further include:

A grouping subunit, configured to divide a data terminator corresponding to a time window having an intersection into a multicast packet. The specific processing is similar to the related description in the first embodiment, and will not be described in detail here.

The grouping unit may further include:

The determining unit is configured to determine whether the number of data termination senders corresponding to the time window having the intersection exceeds a set threshold, and when it exceeds, trigger the grouping subunit to work. The foregoing sending time determining apparatus may be configured in a data source, where the data source may be an SGSN, a GGSN, or an MBMS gateway, or the like, or an evolved base station, or an RNC, or a multicast router.

A fifth embodiment of the present invention provides a multicast system, including a data source and a plurality of data termination senders, where the data source includes:

a data sending time determining means, configured to determine, according to a plurality of data belonging to the same multicast packet, an earliest sending time and a last sending time corresponding to a time window in which the sender must receive the data packet, determining that the data source sends the data packet An optimal time window; selecting a transmission time of the data packet in the optimal time window. The data source transmits a data packet to the data termination sender based on the transmission time. The specific processing is similar to the related description in the first embodiment, and will not be described in detail herein.

In addition, the data source may further include:

The multicast grouping device is configured to perform multicast grouping on the plurality of data termination senders according to a plurality of data terminations, an earliest transmission time and a latest transmission time corresponding to a time window in which the sender must receive the data packet. The specific processing situation is similar to the related description in the first embodiment, and will not be described in detail herein.

The above data termination sender may be a base station, an evolved base station, a multicast router, or an RNC. It can be seen from the specific implementation provided by the foregoing embodiment of the present invention that the data source determines the maximum transmission time of the data packet according to the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet. Good time window; select the sending time in the best time window. The probability that a data packet transmitted based on the transmission time arrives at a plurality of data to terminate the sender at the same time is improved, so that each data termination sender can synchronously transmit the data packet. The spirit and scope of the Ming. Thus, it is intended that the present invention cover the modifications and variations of the inventions

Claims

Claim

A method for determining a data transmission time, comprising:

The transmission time is selected in the optimal time window.

2. The method for determining a data transmission time according to claim 1, further comprising: terminating, according to the plurality of data, an earliest transmission time and a latest transmission time corresponding to a time window in which the sender must receive the data packet, Determining that the plurality of data terminates a multicast packet to which the sender belongs.

The method for determining a data transmission time according to claim 2, wherein the determining, according to the plurality of data, the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet, determining The plurality of data terminates the multicast packet to which the sender belongs, including:

The data terminator corresponding to the time window with intersection is divided into a multicast packet.

The method for determining a data transmission time according to claim 1, further comprising: obtaining, by the data source, a time parameter involved in transmitting the data packet from the data source to the data termination sender, and calculating the time parameter according to the time parameter The data termination sender must receive the earliest transmission time and the latest transmission time corresponding to the time window of the data packet; or

The data source terminates the earliest sending time and the latest sending time corresponding to the time window in which the sender must receive the data packet according to the data reporting end report information fed back by the sender, and the earliest sending time and the latest sending time are data endings. The sender calculates according to the time parameter involved in transmitting the data packet from the data source to the data termination sender, or the earliest transmission time and the latest transmission calculated by the data termination sender according to the time parameter. After the reduction on the basis of time, the earliest transmission time and the latest transmission time are obtained.

The method for determining a data transmission time according to claim 4, wherein the time parameters involved in transmitting the data packet from the data source to the data termination sender include: Maximum IP path transmission time Γ and minimum IP path transmission time from data source to data termination sender^

The data terminates the sender's air interface transmission time T;

The data packet is processed at the sender's processing time Γ _ρ ;

The maximum buffer time of the data packet at the sender of the data is _Γ3⁄4Μ4 and the minimum buffer time T _bMm ; the delay offset T _ffset due to the difference in the merge mode

The method for determining the data transmission time according to claim 5, wherein the IP path transmission time is based on the time when the IP loopback time request message is sent, and the time when the peer end receives the IP loopback time request message. And sending the IP loopback time response corresponding to the request message, and receiving the response time, and determining.

7, as claimed in claim 5 method of determining a data transmission time, characterized in that the maximum packet data buffer time at the end of the sender T _b, the following factors are calculated:

The number m of data waiting to be processed in the buffer, the processing time of each packet Γ _ρ , the maximum deviation of the transmission time of the transmission link, and the maximum deviation of the transmission time of the transmission link from other transmission links in the multicast Ae ;

The data packet is calculated at the minimum buffer time T _{bMm of the} data termination sender, according to the following factors:

The number of data in the cache that has been processed and the processing time of each packet T _p

The method for determining the data transmission time according to claim 7, wherein the number m of data that has been waiting to be processed in the buffer is obtained according to the report information fed back by the sender of the data.

The method for determining the data transmission time according to any one of claims 4 to 8, wherein the data termination report information fed back by the sender is based on one or more feedbacks in the following reporting policy: according to the event The command is reported, periodically reported, and reported according to the specified threshold value related to the reported information. The partial data belonging to the same multicast packet is reported by the sender. When the multicast packet is established, the sender is notified of the data.

10. The method for determining a data transmission time according to claim 5, wherein, according to a time parameter involved in transmitting a data packet from the data source to the data termination sender, the following formula is used to calculate that the data termination sender must receive The earliest sending time corresponding to the time window of the packet:

T - T - T - one

S air tMax T p T b max + T offset

Wherein, 2 indicates the earliest transmission time corresponding to the time window in which the data termination sender must receive the data packet; indicates the air interface transmission time of the data termination sender; ; _Ma indicates the maximum IP path transmission time from the data source to the data termination sender; Γ _ρ indicates the processing time of the data packet at the sender of the data termination;

T _bmax represents the maximum buffer time of the packet at the end of the sender; T. _Ffset represents the delay offset due to the difference in the merge mode;

According to the time parameter involved in transmitting the data packet from the data source to the data termination sender, the following formula is used to calculate the latest transmission time corresponding to the time window in which the data termination sender must receive the data packet:

T - T - T - T + T

L 丄air ¹ tMIN P offset

Where: , indicates the latest transmission time corresponding to the time window in which the data packet must be received by the sender; _M „ indicates the minimum IP path transmission time from the data source to the data termination sender; _ρ indicates the data packet is terminated at the data The sender's processing time; T. _ffset indicates the delay offset due to the difference in the merge mode.

The method for determining a data transmission time according to claim 1, 2, 3 or 4, wherein the data is based on an earliest transmission time and a latest time corresponding to a time window in which the sender must receive the data packet. The sending time determines the best time window for the data source to send the data packet, including:

The intersection of the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet is used as the optimal time window for the data source to transmit the data packet.

12. The method of determining a data transmission time according to claim 1, further comprising: when the data source determines a plurality of data termination senders must receive the most recent time window of the data packet When the intersection of the early transmission time and the latest transmission time is empty, the transmission time is adjusted.

The method for determining a data transmission time according to claim 12, wherein the adjusting the transmission time comprises:

According to each data termination sender must receive the time window corresponding to the transmission time of the data packet, and obtain the data sender with the intersection of the time window; determine whether the number of data termination senders corresponding to the time window having the intersection exceeds the setting. Threshold, when the determined result is exceeded, the data termination sender corresponding to the time window having the intersection is divided into a multicast packet, and the sender must receive the data packet according to the data belonging to the same multicast packet. The earliest sending time and the latest sending time corresponding to the time window, determining an optimal time window for the data source to send the data packet; selecting the sending time in the optimal time window; or

According to each data termination sender must receive the time window corresponding to the transmission time of the data packet, and obtain the data sender with the intersection of the time window; determine whether the number of data termination senders corresponding to the time window having the intersection exceeds the setting. The threshold, when the determined result is not exceeded, adjusts the sending time of the data packet from the data source to a data termination sender according to the method of sending the data packet by point-to-point; or, adjusts the maximum buffer quantity of the multicast service, according to the adjusted The maximum number of buffers and the time parameters involved in transmitting data packets from the data source to the data termination sender, determining the earliest transmission time and the latest transmission time corresponding to the time window in which each data termination sender must receive the data packet, and each The data termination sender must receive the intersection of the earliest transmission time and the latest transmission time corresponding to the time window of the data packet, as the optimal time window for the data source to send the data packet; or

According to the method of sending data packets point-to-point, adjust the sending time of the data packet from the data source to a data termination sender.

The method for determining a data transmission time according to claim 1, 2, 3 or 4, characterized in that the method further comprises:

The data source adjusts the transmission time based on the difference between the time when the packet arrives at the data termination sender and the latest transmission time at which the data termination sender must receive the packet's time window.

15. The method of determining a data transmission time according to claim 14, wherein the data source Adjusting the sending time according to the time adjustment indication sent by the sender of the data, including: the data source reselecting a sending time in the optimal time window; or

The data source re-determines the optimal time window for sending the data packet according to the earliest sending time and the latest sending time corresponding to the time window in which the sender must receive the data packet, and selects the sending time in the optimal time window. time.

A multicast grouping method, comprising:

Determining, according to the plurality of data, the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet, determining the multicast packet to which the plurality of data terminates the sender.

The multicast grouping method according to claim 16, wherein the first transmission time and the latest transmission time corresponding to a time window in which the sender must receive the data packet according to the plurality of data terminations, Multiple data terminates the sender for multicast grouping, including:

18. The multicast grouping method according to claim 17, wherein said intersecting time

19. A data transmission time determining apparatus, comprising:

The optimal time window determining unit 161 is configured to determine the data source sending data according to the earliest sending time and the latest sending time corresponding to the time window that the sender must receive the data packet according to the plurality of data belonging to the same multicast packet. The best time window for the package;

The sending time determining unit 162 is configured to select a sending time in the optimal time window.

The data transmission time determining apparatus according to claim 19, further comprising: a grouping unit, configured to: according to the plurality of data terminations, an earliest transmission time and a maximum time corresponding to a time window in which the sender must receive the data packet The late transmission time determines that the plurality of data terminates the multicast packet to which the sender belongs.

The data transmission time determining apparatus according to claim 19 or 20, further comprising:

a calculation unit for obtaining the time involved in transmitting the data packet from the data source to the data termination sender And calculating, according to the time parameter, an earliest sending time and a latest sending time corresponding to a time window in which the data end sender must receive the data packet; or

An obtaining unit, configured to terminate a sender's report information according to the data, and obtain an earliest sending time and a latest sending time corresponding to a time window in which the sender must receive the data packet, where the earliest sending time and the latest sending time are The data termination sender calculates the time parameter involved in transmitting the data packet from the data source to the data termination sender, or the earliest transmission time and the most calculated by the data termination sender according to the time parameter. The earliest transmission time and the latest transmission time obtained after the reduction is based on the late transmission time.

The data transmission time determining apparatus according to claim 21, wherein the optimal time window determining unit 161 comprises:

The data transmission time determining apparatus according to claim 19, further comprising: a detecting unit, configured to determine an earliest transmission time and a maximum time corresponding to a time window in which the plurality of data termination senders must receive the data packet Whether the intersection of the late sending times is empty;

a time adjustment unit, configured to adjust a transmission time when the detecting unit detects that the intersection is empty.

The data transmission time determining apparatus according to claim 23, wherein the time adjustment unit comprises:

a first time adjustment subunit, configured to: according to each data, a time window corresponding to a transmission time at which the sender must receive the data packet, obtain a data sender having an intersection of the time window; and determine a data termination sender corresponding to the intersection window Divided into a multicast packet, and according to the data belonging to the same multicast packet, the earliest transmission time and the latest transmission time corresponding to the time window in which the sender must receive the data packet, determine the most data packet transmission data packet. Good time window; select in the best time window Send time; or,

a second time adjustment subunit, configured to: according to each data, the time window corresponding to the sending time that the sender must receive the data packet, obtain the data sender with the intersection of the time window; determine the data end corresponding to the time window with the intersection When the number of senders does not exceed the set threshold, the transmission time of the data packet from the data source to a data termination sender is adjusted according to the method of transmitting the data packet by point-to-point; or, the third time adjustment sub-unit is used to adjust the multicast. The maximum number of caches of the service, according to the adjusted maximum number of caches and the time parameters involved in transmitting data packets from the data source to the data termination sender, determining the earliest transmission corresponding to the time window in which each data termination sender must receive the data packet The time and the latest sending time, and each data terminates the intersection of the earliest sending time and the latest sending time corresponding to the time window in which the sender must receive the data packet, as the best time window for the data source to send the data packet; or

The fourth time adjustment sub-unit is configured to adjust the sending time of the data packet from the data source to a data termination sender according to the method of sending the data packet point-to-point.

The data transmission time determining apparatus according to claim 19, further comprising: an adjusting unit, configured to terminate the time and data of the sender according to the data packet arrival data, and terminate the time window in which the sender must receive the data packet. The difference between the corresponding latest transmission times is adjusted for the transmission time.

The data transmission time determining apparatus according to claim 25, wherein the adjustment unit comprises:

a first adjusting subunit, configured to reselect a sending time in the optimal time window; or, a second adjusting subunit, configured to send, according to the data, the earliest sending corresponding to the time window that the sender must receive the data packet The time and the latest sending time, re-determine the best time window for sending the data packet, and select the sending time in the best time window.

27. A multicast grouping device, comprising:

An obtaining unit, configured to acquire a plurality of data terminations, an earliest sending time and a latest sending time corresponding to a time window in which the sender must receive the data packet; a grouping unit, configured to perform multicast grouping on the plurality of data termination senders according to a plurality of data terminations, an earliest transmission time and a latest transmission time corresponding to a time window in which the sender must receive the data packet.

The multicast grouping apparatus according to claim 27, wherein the grouping unit comprises: a grouping subunit, configured to divide a data terminator corresponding to a time window having an intersection into a multicast packet .

The multicast grouping device according to claim 28, wherein the grouping unit further comprises:

The determining unit is configured to determine whether the number of data termination senders corresponding to the time window having the intersection exceeds a set threshold, and when it exceeds, trigger the grouping subunit to work.

30. A multicast system, comprising: a data source and a plurality of data termination senders, wherein the data source sends a data packet to the data termination sender, and the data source includes:

a data sending time determining means, configured to determine, according to a plurality of data belonging to the same multicast packet, an earliest sending time and a last sending time corresponding to a time window in which the sender must receive the data packet, determining that the data source sends the data packet An optimal time window; selecting a transmission time of the data packet in the optimal time window.

The multicast system according to claim 30, wherein the data source further comprises: a multicast grouping device, configured to: according to the plurality of data terminations, the earliest time window corresponding to the time that the sender must receive the data packet The sending time and the latest sending time, and multicasting the plurality of data termination senders.

The multicast system according to claim 30 or 31, wherein the data source comprises: a serving general packet radio service support node SGSN, or

Gateway General Packet Radio Service Support Node GGSN, or,

Multimedia Broadcast/Multicast Service Gateway, or,

Base station, or,

Wireless network controller RNC, or,

Multicast router.