WO2007060577A1

WO2007060577A1 - Method and apparatus for download in digital broadcasting system

Info

Publication number: WO2007060577A1
Application number: PCT/IB2006/054261
Authority: WO
Inventors: Kairaz Contractor; Fang Liu
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2005-11-22
Filing date: 2006-11-15
Publication date: 2007-05-31

Abstract

The invention discloses a method and an apparatus for download in a digital broadcasting system. The method first estimates available bandwidth in transport stream of the digital broadcasting system, then assigns a program stream for a downloadable file by use of the available bandwidth, finally transmits the downloadable file in the assigned program stream. By transmitting the downloadable file in dedicated program stream, not only the download rate of a terminal device is increased but also the system resource is effectively utilized.

Description

METHOD AND APPARATUS FOR DOWNLOAD IN DIGITAL BROADCASTING

SYSTEM

FIELD OF THE INVENTION

The invention relates to a digital broadcasting technology, in particular, to a method and an apparatus providing download service in digital broadcasting system.

BACKGROUND OF THE INVENTION

The simple mobile voice communication could not meet the requirement of the need for information due to the prevailing of mobile communication. The perspectives of various new applications, which could provide much more contents that are convenient in handling business/entertainment and provides more information, are promising. For example, one of the applications is watching TV program on the mobile terminals. For those broadcast providers, the service of providing TV program on mobile terminal could bring in huge potential profit. The application could be further extended to provide large file downloading for multiple terminal users, and the file downloading is not only limited to TV video stream but also could be other contents such as real-time game, software patch etc.

For this purpose, ETSI (European Telecommunications Standards Institute) has disclosed the standard of DVB-H (Digital Video Broadcasting-Handheld). DVB-H is an approach to extend the DVB-T (Digital Video Broadcasting-Terrestrial) standard, and the researches of the DVB-H are mainly concentrated on the applications of handheld devices.

For those conventional DVB systems, the software download service is one of its essential features, and one of standardized applications as well. The "Digital Video Broadcasting (DVB); DVB Data Download Specification; Part 1: Simple Profile" in the file of ETSI TR 102006-1 Vl.1.1 and "Digital Video Broadcasting (DVB); Specification for System Update in DVB Systems" in the file of ETSI TR 102006-1 Vl.2.1 could be referred to for more detailed explanation.

One of the main purposes of providing software download service in DVB system is to fix the bugs in the system software and to update the user's device in order to make the device containing new functions. Compared with other approaches to download software, such as by means of serial interface, flash memory card, optical recording medium or internet, the advantage of download software in DVB system over-the-air (OTA) is that basic apparatus in a existing network could be fully utilized, without adding any other peripheral devices.

Fig.l illustrates the basic structure of TS (Transport Stream) in a conventional DVB system. The TS contains a plurality of different PS (Program Stream), and each PS further includes video stream, audio stream and private stream. The diameter of the cylinders in Fig. 1 represents various streams and indicates the bandwidth each occupies. The software data module provided to terminal users are arranged in certain sequence, and then are sent through private stream sequentially.

However, the conventional software download method of DVB system has a lot of disadvantages. First, the bandwidth allocated by the system is very limited and the private stream only occupies a small portion of whole bandwidth, as shown in Fig.l. Thus, the software downloading process is very slow and takes a lot of time. Since the software for downloading are sequentially transmitted, it could take a long time for the terminal users to wait for beginning to transmit the software he wanted. For those handheld devices using battery as power source, it is extremely difficult to wait such a long time to download software due to the limit of the battery. Usually, the downloaded software is stored in a RAM (Random Access Memory) of the receiving device. Thus, if the receiving device is switched off because out of power or other interruptions, the whole software should be re-downloaded; or if the receiving device is switched off before transmitting the software, the user may miss the downloading of software.

Also, due to the limits on bandwidth and download speed, the network operator could only provide some critical software for user's downloading, which somewhat hinders the wide application and potential market revenue of software downloading in DVB system.

Therefore, it is necessary to propose a preferable software downloading scheme, which could provides highly efficient download service to the user by making full use of system resources. Consequently, users could download software conveniently and quickly, in the mean time, the network operater could gain more market revenue by providing more prosperous services based on this scheme.

OBJECTAND SUMMARY OF THE INVENTION

One object of the invention is to provide a download method and apparatus used in digital broadcast system. The method and apparatus could bring efficient download service to the user by making full use of the bandwidth resources of the system.

The download method used in digital broadcast system according to the invention, including the steps:

(a) estimating the available bandwidth in system transport stream;

(b) assigning a program stream for a downloadable file by use of said available bandwidth; and (c) transmitting said downloadable file in the assigned program stream.

The download apparatus used in digital broadcast system according to the invention, comprises: a bandwidth allocator, which estimates the bandwidth available for downloading in the system transport stream; and a controller, which assigns a program stream for a downloadable file by use of the available bandwidth acquired by the bandwidth allocator, in order to transmit said downloadable file in the assigned program stream.

The download method and apparatus used in digital broadcast system according to the invention provide download service through dedicated program stream, which not only increases download speed but also utilize the system bandwidth resources more efficiently. In the mean time, since the bandwidth for transmitting the downloadable files is increased and those downloaded files do not need to be multiplexed and broadcasted in carousel, the users' waiting time could be reduced.

By referring to the detailed explanation with accompanying figures and the claims, as well as a more comprehensive understanding of the invention, other objects and effects of the invention will be more apparent and easy to understand.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more clearly described from consideration of the following embodiment descriptions in connection with accompanying figures in which: Fig.1 shows a conventional structure of DVB system transport stream;

Fig.2 shows a structure of DVB-H system transport stream of the present invention;

Fig.3 shows the block diagram of a broadcast apparatus of DVB-H system for providing download service in the present invention;

Fig.4 partially shows of signalling structure of DVB-H system for providing download service in the present invention.

In all the figures, the same reference numbers indicate the similar or corresponding functions/features . DETAILED DESCRIPTION OF THE INVENTION

In a digital broadcasting system, Transport Stream (TS) is constructed by a plurality of different Program Streams (PSs). The bandwidth of each PS is allocated according to the corresponding parameters in broadcasting system. Those parameters are generally determined according to the service provided by the broadcasting system.

In the systems focusing on the application of handheld devices, such as DVB-H etc., the receiving terminals are mainly handheld devices. Because of the limits imposed on the hardware of those handheld devices, such as small display panel and lower resolution etc., when compared with the video stream in the DVB-T system, the video stream broadcasted in DVB-H system does not need high speed and high resolution. Therefore, in the DVB-H system, the bandwidth allocated to each PS could be adjusted to be relatively small, such that the utilization of system resource could be more flexible.

For this purpose, a TS-PS system structure scheme according to the present invention can provide a quick download service while providing multimedia broadcasting service by use of system resource more efficiently. The following will take DVB-H system as an example to explain in detail.

Two types of PS are defined in the TS of DVB-H system of the present invention. The first type is standard PS, which is the same with conventional PS, for transmitting video or audio digital multimedia contents, and the second type PS is extended PS, mainly for transmitting downloadable objects (i.e. for software download service etc.).

Referring to the Fig.2, various types of PSs are included in the TS. A standard PS includes video and audio contents and an extended PS includes a plurality of different downloadable objects for user's downloading. The downloadable objects could be software program, a module of a software program or data for executing certain program etc. To efficiently use bandwidth and save time, multi-path of downloadable data could be transmitted in one extended PS simultaneously, and the download rate and resources for each path of downloadable data could be individually adjusted. The operator could make this adjustment according to the fee paid by the user or the size of the downloadable data, in order to utilize the limited bandwidth more efficiently.

Based on the requirement in practical application, each downloadable object could be further divided into a plurality of small data blocks in order to increase downloading efficiency. If some data blocks have download errors during the download procedure, only the data block with errors needs to be re-downloaded rather than trying to download the complete downloadable object again.

In the DVB-H system, the extended PS could be temporarily employed and be dynamically adjusted. That is, if the download service is requested, the system could establish a new PS in TS as an extended PS dedicated to transmit downloadable data, or the system could assign an idle standard PS in TS as extended PS for providing download service temporarily.

The bandwidth for the extended PS is dynamically allocated, if a huge amount of data files need to be transmitted in a certain time interval, the system may allocate a larger bandwidth for the extended PS in order to provide a download service with higher rate.

After finishing the download service, the system could take back the bandwidth allocated to the extended PS. Since the video stream for broadcasting in DVB-H system could achieve desirable visual effect without high rate and high resolution, even if the bandwidth of TS are completely occupied by standard PS, the bandwidth occupied by standard PS could be somewhat reduced in order to get some available bandwidth which could be allocated to extended PS temporarily.

Although the present invention has changed the TS-PS structure of DVB-H system, the conventional hardware devices of DVB-H system, which includes broadcasting devices and receiving devices etc., still could be used. Referring to fig.3, a broadcasting device of the present invention includes a downloading management unit 10, a bandwidth allocating unit 20 and an extended PS control unit 30. The downloading management unit 10 could receive download service information, such as downloadable contents or downloading instructions, from the system, and send corresponding instructions to bandwidth allocating unit 20 and extended PS control unit 30 depending on whether a download service or a downloadable content currently exists. The bandwidth allocating unit 20 allocates bandwidth to extended PS depending on the current bandwidth information of the system and the instruction from the downloading management unit 10. The extended PS control unit 30 establishes a new extended PS or assigns an idle standard PS as extended PS temporarily in order to transmit the content of download service, depending on the instruction from the downloading management unit 10 and the bandwidth acquired from bandwidth allocating unit 20. If the current available bandwidth is not sufficient, the bandwidth allocating unit 20 could also get more available bandwidth for allocating to the extended PS temporarily by adjusting the bandwidth of standard PS.

In order to discriminate different program streams in the transport stream in DVB-H system, service information was added into each transport stream packet, such that the receiving terminal could recognize different program contents. The service information mainly comprises service Bouquet Association Table (BAT), Network Information Table (NIT) and Program Map Table (PMT) etc. As far as a receiver is concerned, it will find different tables to which service information corresponds, and search for Packet Identifier (PID) code of the desired program and corresponding clock via these service information tables, then reproduce the program.

In the present invention, according to above discussion, the download service will be executed through an assigned extended PS in the TS if the system requests this service. The software download service will be marked by specific parameters of a PS Descriptor. In the DVB-H system, the specific parameter could be PMT. If general multimedia contents are transmitted via PS, the PMT will be the same as basic PMT in conventional DVB-H system. The PMT will be different from conventional PMT only if the PS is used for data service such as software downloading etc. In this way, the compatibility of the invention over general multimedia broadcasting could be ensured.

One signalling procedure of the present invention is described in fig.4. The receiving terminal first acquires NIT or BAT, then finds corresponding PMT according to the information in NIT or BAT. The PMT describes the structure of PS. In general, there are two types of data stream, one is ordinary video stream, the other one is service stream, which includes contents such as software/game downloading etc. The PMT also includes Object Download Information (ODI) structure, which describes the features of complete module download. If the downloadable module is divided into multiple data blocks for transmitting, Object Block Information (OBI) will be used for describing the features of the data blocks.

Moreover, User Notification Table (UNT) could be used for notifying the user to download software before the software downloading broadcasting starts.

According to the method and apparatus of the present invention, download rate is increased by providing download service through dedicated PS. In the mean time, since the bandwidth for transmitting downloadable files is increased, these downloadable files do not need to be multiplexed and broadcasted in turn. The downloading period and the waiting time are therefore reduced, and the system bandwidth resources are utilized more effectively without influencing the multimedia content broadcasting.

The method and apparatus of the present invention could be not only used in DVB-H system but also used in other similar broadcast or communication systems, such as Digital Multimedia Broadcast-Handheld (DMB-H) systems etc. It will be appreciated by those skilled in the art, the method and apparatus for download in digital broadcasting systems could be modified without departing from the scope of the invention. Therefore, the scope of protection of the invention should be defined by the content of appended claims.

Claims

CLAIMS:

1. A method for download in digital broadcasting system, including steps:

(a) estimating available bandwidth in system transport stream;

(b) assigning a program stream for a downloadable file by use of the available bandwidth; and

(c) transmitting the downloadable file in the assigned program stream.

2. The method according to claim 1, wherein, the step (b) further includes step:

(bl) temporarily decreasing bandwidth of other program streams in the transport stream, in order to obtain more available bandwidth.

3. The method according to claim 2, further including step:

(dl) recovering the bandwidth for the other program streams which is decreased in the step (bl), after the transmitting of the downloadable file is finished.

4. The method according to claim 1 or 2, further including a step for establishing a new program stream as the assigned program stream.

5. The method according to claim 1 or 2, wherein the assigned program stream in the step (b) is an idle program stream.

6. The method according to claim 1 or 2, further including step:

(d2) if a new downloadable file is acquired before the transmitting of the downloadable file finishes, the new downloadable file will be transmitted in the assigned program stream as well.

7. An apparatus for download in digital broadcasting system, comprising:

a bandwidth allocating means for estimating available bandwidth in system transport stream; and a control means, for assigning a program stream for a downloadable file by use of the available bandwidth acquired by the bandwidth allocating means, to transmit the downloadable file in the assigned program stream.

8. The apparatus according to claim 7, wherein the bandwidth allocating means is also for temporarily decreasing bandwidth of other program streams in the transport stream, in order to acquire more available bandwidth, and recovering the bandwidth for other program streams after the transmitting of the downloadable file is finished.

9. The apparatus according to claim 7 or 8, wherein the control means is further for establishing a new program stream as the assigned program stream.

10. The apparatus according to claim 7 or 8, wherein the control means regards an idle program stream as the assigned program stream.

11. The apparatus according to claim 7 or 8, wherein if a new downloadable file is requested before the transmitting of the downloadable file is finished, the control means is further for transmitting the new downloadable file in the assigned program stream as well.