CN107172026A - A kind of burst transfer dispatching method of mobile media broadcasting network - Google Patents

Abstract

The invention discloses a burst transmission scheduling method of a mobile multimedia broadcasting network. The method comprises: (1) sorting each channel in an increasing manner according to the burst cycle of each channel; (2) first scheduling and sorting The first channel of the first channel, followed by scheduling the second channel after sorting, and so on, until the scheduling of each channel after the sorting is completed, thus completing the first channel scheduling; (3) then proceed to the next channel scheduling, the scheduling The sequence and method are the same as the previous one. The invention not only overcomes the scheduling confusion caused by the RPS scheme when the buffer lengths of different types of receivers in the network are different, but also overcomes the unreasonable phenomenon that some channels cannot be scheduled due to the RPS scheme in extreme cases, and provides a new solution for mobile multimedia broadcasting. The design and implementation of burst transmission scheduling in the network provides an effective solution and helps to improve the burst transmission scheduling performance of mobile multimedia broadcasting network.

Description

A Burst Transmission Scheduling Method for Mobile Multimedia Broadcasting Network

technical field

The invention relates to the technical field of wireless communication, in particular to the transmission technology of a wireless digital multimedia broadcasting system.

Background technique

With the rapid development of mobile technology, the spread of multimedia services has extended from traditional wired networks to wireless users. Relevant mobile TV standards include DVB-H (Digital Video Broadcast-Handheld), MediaFLO (Forward Link Only), ATSC M/H (Advanced Television Systems Committee-Mobile/Handheld), MBMS (Multimedia Broadcast Multicast Services), T-DMB (TerrestrialDigital Multimedia Broadcast) has been widely deployed.

Nevertheless, mobile TV still faces some practical problems, such as the limited use time under the battery power limit. In order to reduce the receiver's energy consumption, the concept of time slicing is proposed in DVB-H and ATSC M/H. Time slicing involves broadcasting video data in bursts at a rate much higher than the bit rate of the video stream, so mobile devices can turn off their receivers between adjacent bursts to save energy. The higher the burst bit rate, the longer the transmitter is off, saving more energy. Due to the need to broadcast multiple TV channels, it is necessary to design a burst scheduling algorithm. In Nokia's MBS (Mobile Broadcast Solution) solution, network operators manually set a common burst period for all TV channels. In the same time period, all TV channels have the same number of bursts, but the channel burst length It varies according to the transmission rate of the channel. When the transmission rate of each channel is very different, the energy-saving effect is not obvious, and it is easy to cause buffer overflow or idleness. DBS (Double Buffering Scheduling) is suitable for any channel bit rate and is an effective burst scheduling method. In DBS, a frame is divided into different number of subframes for different TV channels, the mobile device's buffer is divided into two equal parts, and in each subframe of a channel, the mobile device receives bursts to Fill a part of the buffer while taking away the burst of the previous subframe stored in the other part of the buffer. As long as the total burst length of each subframe is equal to half the length of the receiver buffer, buffer overflow or idle will not occur , its disadvantage is that only half of the buffer of the receiver is used to store bursts, which reduces the energy saving rate. RPS (Regulated Period Scheduling) is less complex than DBS, and obtains a higher energy-saving rate by optimizing the length of the frame. However, RPS still has some defects. For example, the limitation of burst period does not consider the needs of different channels, and the consideration of channel switching delay is also lacking, and it is not suitable for VBR (Variable Bit Rate) coding.

In the RPS scheme, the length of the burst period of a channel is limited by the maximum burst period, and the maximum burst period depends on the burst rate of data, the buffer length of the receiver, and the data usage rate of the receiver. Since the receiver buffer lengths of different types of mobile devices are not necessarily the same, for different mobile devices, the maximum burst period of the same channel will be different, which causes scheduling confusion and is not feasible. In addition, the calculation of the channel burst period in the PRS only needs to meet the condition that the channel burst period is smaller than the maximum channel burst period, and some channels may be over-scheduled while some channels cannot be effectively scheduled.

Contents of the invention

Based on the above background, the present invention provides a burst transmission scheduling method suitable for mobile multimedia broadcasting networks by reasonably setting the maximum burst period of the channel and optimizing the constraint conditions of the burst period on the basis of the RPS scheme. The present invention not only overcomes the scheduling confusion caused by the RPS scheme when the buffer lengths of different types of receivers in the network are different, but also provides an effective solution for the design and realization of burst transmission scheduling in the mobile multimedia broadcasting network; the present invention also overcomes the The unreasonable phenomenon that some channels cannot be scheduled due to the RPS scheme in extreme cases helps to improve the burst transmission scheduling performance of the mobile multimedia broadcasting network. Described below are the main steps of the technical solution of the present invention.

(1) According to the burst period T _i of each channel, i=1, 2, ... N, N is the number of channels; the channels are sorted in an increasing manner; the burst periods corresponding to the sorted channels are respectively T _i ′=T _b,i ′+T _c,i ′; T _b,i ′ is the length of time for the i-th channel to transmit data in a burst period after sorting, and T _c,i ′ is the i-th channel after sorting The length of time a channel does not transmit data within a burst period.

(2) First schedule the sorted first channel, and the start time of the burst cycle of the first channel is the start time of the jth frame Second, schedule the sorted second channel, the start time of the burst cycle of the second channel By analogy, until the scheduling of the Nth channel after sorting is completed, the burst cycle start time of the Nth channel Thus, the first channel scheduling of the jth frame is completed.

(3) After the first channel scheduling of the jth frame is completed, the next channel scheduling of the jth frame is performed, and the order and method of scheduling are the same as the previous one.

detailed description

In the actual burst transmission scheduling process, it is necessary to calculate the burst period T _i of the i-th channel. Currently, there are many methods for determining the burst period. The present invention provides a preferred determination method below. Define the burst period of the i-th channel N is the number of channels, Q _i is a natural number, T _b,i is the time length for the i-th channel to transmit data within a burst period, T _c,i is the time for the i-th channel not to transmit data within a burst period length of time. Therefore, to determine the burst period T _i of the _i -th channel is to determine the value of ki, considering three factors: (1) each channel in each frame is scheduled at least once; (2) the i-th channel The burst period T _i of the i channel is less than or equal to the maximum burst period T _i ^max of the i channel; (3) the burst period of each channel should be less than or equal to the length τ of one frame, Therefore, for i=1, 2, ... N, k _i should satisfy the condition at the same time A natural number as small as possible for T _i ≤ T _i ^max and T _i ≤ τ.

At present, there are various definitions for the determination of the above-mentioned maximum burst period T _i ^max , and the present invention provides a preferred determination method below. Two factors are considered when determining the maximum burst period T _i ^max of the i-th channel: (1) the buffer lengths of different types of receivers, and (2) each channel is scheduled at least once in each frame. Define the maximum burst period of the i-th channel as R is the data burst rate of each channel, B ^min is the minimum buffer length of different types of receivers, and C _i is the data usage rate of the i-th channel of the receiver.

The channel scheduling of each frame starts from the start time of each frame, and the burst transmission scheduling method in the jth frame (j=1,2,3...) is as follows:

Step 1: Calculate the burst period T _i of the i-th channel, i=1, 2, . . . , N.

Step 2: According to the burst period T _i of each channel, the channels are sorted in an increasing manner, and the burst periods corresponding to the sorted channels are respectively T _i ', i=1, 2, ..., N; correspondingly, T _i ′=T _b,i ′+T _c,i ′, T _b,i ′ is the length of time for the sorted i-th channel to transmit data in a burst period, and T _c,i ′ is the sorted The length of time during which the i-th channel does not transmit data within a burst period.

Step 3: Complete the first channel scheduling from the starting time of the jth frame, that is, first schedule the sorted first channel, and the burst cycle start time of the first sorted channel in the first channel scheduling is the start time of the jth frame Next is the second channel after sorting, the burst cycle start time of the second channel after sorting in the first channel scheduling By analogy, until the scheduling of the Nth channel after sorting is completed, the burst cycle start time of the Nth channel after sorting in the first channel scheduling

Step 4: After the first channel scheduling of the jth frame is completed, the next channel scheduling of the jth frame is performed, and the scheduling sequence is the same as that of the previous channel scheduling.

Certain principles should be followed in each channel scheduling process, and slightly different effects will be obtained by following different principles. This embodiment presents a preferred principle here in order to obtain the greatest beneficial effect.

(1) The start time of the burst period of each channel in the first channel scheduling of frame j is the difference between the start time of the burst period of the channel in the last channel scheduling of frame j and the burst period of the channel and the corresponding time; however, if the calculated start time of the channel in a channel scheduling burst period, the time when the channel transmits data in the scheduled burst period and the previous channel scheduling has been scheduled If there is overlap or partial overlap in the time of transmitting data in the burst period of each channel, the start time of the burst period of the channel in the sub-channel scheduling should be delayed until there is no overlap.

(2) When the sum of the start time of the burst cycle of any channel in the first channel scheduling of frame j and the burst cycle of the channel is greater than or equal to that of the channel in the first channel scheduling of frame j+1 At the start time of the burst period, the scheduling of the channel in this and subsequent channel scheduling in the jth frame is terminated.

(3) When all channels terminate the scheduling in the first channel scheduling of the jth frame, the channel scheduling process of this frame ends.

Claims (4)

1. A burst transmission scheduling method of a mobile multimedia broadcasting network, said method comprising: (1) According to the burst period T _i of each channel, i=1, 2, ... N, N is the number of channels; the channels are sorted in an increasing manner; the burst periods corresponding to the sorted channels are respectively T _i ′=T _b,i ′+T _c,i ′; T _b,i ′ is the length of time for the i-th channel to transmit data in a burst period after sorting, and T _c,i ′ is the i-th channel after sorting The length of time that a channel does not transmit data within a burst period; (2) First schedule the sorted first channel, and the start time of the burst cycle of the first channel is the start time of the jth frame j=1,2,3...; secondly schedule the second channel after sorting, the start time of the burst cycle of the second channel By analogy, until the scheduling of the Nth channel after sorting is completed, the burst cycle start time of the Nth channel Thus, the first channel scheduling of the jth frame is completed; (3) After the first channel scheduling of the jth frame is completed, the next channel scheduling of the jth frame is performed, and the order and method of scheduling are the same as the previous one. 2. The method according to claim 1, wherein said burst period T _i is defined as a burst period i=1, 2,...N; k _i =1, 2,...Q _i ; define the maximum burst period of the i channel as Where: T _b,i is the time length during which the i-th channel transmits data in a burst period, T _c,i is the time length during which the i-th channel does not transmit data within a burst period, τ is the time length of a frame length, R is the data burst rate of each channel, B ^min is the minimum buffer length of different types of receivers, C _i is the data usage rate of the i-th channel of the receiver, N is the number of channels, and Q _i is a natural number. 3. The method according to claim 2, wherein said _ki is determined in the following manner: while satisfying The smallest natural number under the condition of T _i ≤T _i ^max and T _i ≤τ. 4. The method according to claim 1, 2 or 3, further comprising: each channel scheduling follows the following principles: (1) The start time of the burst period of each channel in the first channel scheduling of frame j is the difference between the start time of the burst period of the channel in the last channel scheduling of frame j and the burst period of the channel and the corresponding time; if the calculated start time of the channel in a channel scheduling burst period, the time when the channel transmits data in the scheduled burst period and the channels already scheduled in previous channel scheduling If there is overlap or partial overlap in the time of transmitting data in the burst period of the channel, delay the start time of the burst period of the channel in the sub-channel scheduling until there is no overlap; (2) When the sum of the start time of the burst cycle of any channel in the first channel scheduling of frame j and the burst cycle of the channel is greater than or equal to that of the channel in the first channel scheduling of frame j+1 At the start time of the burst period, terminate the scheduling of the channel in the jth frame and subsequent channel scheduling; (3) When all channels terminate the scheduling in the first channel scheduling of the jth frame, the channel scheduling process of this frame ends.