EP1459529A1

EP1459529A1 - A method and system for announcing a ip based service in a transmission stream

Info

Publication number: EP1459529A1
Application number: EP02779591A
Authority: EP
Inventors: Jarno Kallio; Jani VÄRE
Original assignee: Nokia Oyj; Nokia Inc
Current assignee: Nokia Oyj; Nokia Inc
Priority date: 2001-11-19
Filing date: 2002-11-18
Publication date: 2004-09-22
Also published as: FI20012245A7; WO2003045054A1; AU2002342939A1; FI20012245A0

Abstract

A method for discovering service announcements for IP based services in MPEG-2 Transport Stream using PSI tables. These service announcements contain the mapping of IP based services into physical and link layer parameters and description of content. With the method described in these embodiments, the receiver can automatically discover all the IP based services existing in the TS described in SA without requiring any use of the interaction network. Also only a few configuration is required in the transmission network in order to provide full access to all available broadcast IP based services.

Description

A METHOD AND SYSTEM FOR ANNOUNCING A IP BASED SERVICE IN A TRANSMISSION STREAM

TECHNICAL FIELD OF THE INVENTION

This invention relates to systems and methods for distributing data over a data link.

BACKGROUND OF THE INVENTION

Broadcast has an almost century long tradition in radio. Even with TV, the history goes back to 1930's. Broadcasting has been successful throughout the world in bringing both entertainment and information to mass audiences.

The latest step in broadcasting is the digitalisation of both radio and TV. Digital radio has not gained much acceptance on the market. However, many hope that digital TV will bring new benefits and services to the consumer and, as a result, generate new revenue streams for the broadcasting industry. The basic concept of the TV service itself has, however, not changed much. Rather, the TV lives on as before even if it has become digital.

In later half of 1990's we saw the boom of the Internet. A whole set new of services and content became available to the consumers during a short, revolutionary and hype intense period. That period introduced e-commerce, Internet Service Providers (ISPs), Portals, eyeballs game, dotcom companies and even the new economy. The developments in both access technologies (e.g. ADSL) and coding technologies (e.g. MPEG-2 streaming) has made it possible to bring rich media content like video content to homes via the Internet. Despite of these technology and market breakthroughs media houses have been reluctant to distribute their content via the Internet due to its "free-of-charge" nature and the direct threat of piracy. Internet has also not been able to challenge the role of traditional media as the primary advertisement platform despite is great popularity. Broadcast provides the receiver device with huge amount of information. The receiver device needs to obtain linking and guidance information from broadcast information for obtaining services which can be indicated in the linking and guidance information.

SUMMARY OF THE INVENTION

Now a method and arrangement has been invented where at least one service announcement is discovered in a stream that is transferred over a data link.

In accordance with a first aspect of the invention there is provided a method for announcing of a service in a transmission stream that a digital broadcast network is transmitting, the method comprising: generating a first table and a second table, linking the first table with the second table, transmitting the first table and the second table to a wireless terminal via the digital broadcast network, receiving the first table at the wireless terminal, wherein the first table comprises an identifier of the second table, and identifying the second table in the transmission stream using the identifier, and identifying a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.

Advantageously, service discovery for all IP based services provided in the digital broadcast network is provided automatically. Service announcements can be obtained without the use of the interaction network. There is only required few configurations in the digital broadcast network in order to provide full access to all available IP based services. Since the embodiment of the invention uses only Program Service Information (PSI) tables that are defined in MPEG-2, the invention provides a compatible solution for ATSC systems as well as for DVB systems. Preferable embodiments of the invention provide method for discovering service announcements. These service announcements contain the mapping of IP based services into physical and link layer parameters and description of content. With the method described in these embodiments, the receiver can automatically dis- cover all the IP based services existing in the TS and described in Service Announcements (SA) without requiring any use of the interaction network. Also only a few configurations are required in the transmission network in order to provide full access to all available broadcast IP based services.

In the preferred embodiment the first table comprises a Program Association Table (PAT). The second table comprises a Program Map Table (PMT). The digital broadcast network is one of a Digital Video Broadcasting (DVB) network, a network compliant for Advanced Television Systems Committee (ATSC) and a Digital Audio Broadcasting (DAB) network. Advantageously, the digital broadcast network may comprise a terrestrial digital video broadcasting (DVB-T) network. The identifier comprises a Packet Identifier (PID). The component comprises Service Announcements (SA). The component identifier comprises stream_type_id. The transmission stream comprises a transport stream.

In accordance with a second aspect of the invention there is provided a method in a transmission for announcing of a service in a transmission stream that a digital broadcast network is transmitting, the method comprising: generating a first table and a second table, linking the first table with the second table, and transmitting the first tables to a wireless terminal via the digital broadcast network, wherein the first table comprises an identifier of the second table, and the second table comprises a component, which component is tagged with a component identifier contained in the second table, the component comprising parameters for the reception of the service.

In accordance with a third aspect of the invention there is provided a method in a reception for discovering a service in a transmission stream that a digital broadcast network is transmitting, the method comprising: receiving a first table at a wireless terminal, wherein the first table comprises an identifier of a second table, and identifying the second table in the transmission stream using the identifier, and identifying a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.

In accordance with a fourth aspect of the invention there is provided a wireless terminal for discovering a service in a transmission stream that a digital broadcast network is transmitting, the wireless terminal comprising: means for receiving a first table at a wireless terminal, wherein the first table comprises an identifier of a second table, and means for identifying the second table in the transmission stream using the identifier, and means for identifying a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.

In accordance with a fifth aspect of the invention there is provided a system for announcing of a service in a transmission stream that a digital broadcast network is transmitting, the system comprising: means for generating a first table and a second table, means for linking the first table with the second table, and means for transmitting the tables to a wireless terminal via the digital broadcast network, wherein the first table comprises an identifier of the second table, and the second table comprises a component, which component is tagged with a component identifier contained in the second table, the component comprising parameters for the reception of the service.

In accordance with a sixth aspect of the invention there is provided a computer program product comprising a program of instructions executable by a computing system for processing an announcement of a service in a transmission stream that a digital broadcast network is transmitting, the computer program product comprising: computer program code for causing the system to generate a first table and a second table, computer program code for causing the system to link the first table with the second table, computer program code for causing the system to transmit the tables to a wireless terminal via the digital broadcast network, computer program code for causing the system to receive the first table at the wireless terminal, wherein the first table comprises an identifier of the second table, computer program code for causing the system to identify the second table in the transmission stream using the identifier, and computer program code for causing the system to identify a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows an example of Program Associating Table (PAT),

Figure 2 shown an example of Program Map Table (PMT) in accordance with a further embodiment of the invention,

Figure 3 shows a general architecture of the system where principles of the invention can be applied,

Figure 4 shows table structures and relationships by which a service is announced in a transmission stream in an embodiment of the invention, Figure 5 depicts in a form of a flowchart a method for announcing a service by generating PAT and PMT table structure in a digital broadcast network in accordance with an embodiment of the invention, Figure 6 depicts in a form of a flowchart a method for announcing a service in MPEG-TS using PAT and PMT tables in the wireless terminal in accordance with a further embodiment of the invention,

Figure 7 depicts a wireless terminal for discovering service announcements in MPEG-TS using PAT and PMT tables.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Digital Video Broadcasting (DVB) offers a high bandwidth transmission channel wherein delivery is typically multicast. The high bandwidth transmission channel can offer a user of such system various services. Identifications for the various services are necessary to focus on appropriate receivers. Preferably, a Terrestrial Digital Video Broadcasting (DVB-T) is applied in the invention. Alternatively, the invention is also applicable in transmissions according to Advanced Television Systems Committee (ATSC) because the applied transfer protocol is compatible in both systems.

The digital broadcast transmission provides a receiver device with huge amount of data information. The receiver device should be able find the relevant data infor- mation among the huge amount of transmitted data information. The receiver device requires certain parameters in order to be able to receive the relevant service which is intended for the receiver device. Because the digital broadcast transmission can distribute a lot of data, it can also distribute the parameters which enables the receiver device to discover the service among many services. These parame- ters are digitally broadcast to the receiver device. The receiver device recognises them and can modify itself in accordance with the parameters. Therefore, the receiver device can now start receiving the service, by identifying the relevant data from the huge amount of data in the broadcast transmission.

Some embodiments of the applied transfer protocol in the invention are based on the methods and system presented in a specification ISO/IEC 13818-1 Information Technology - Generic Coding of Moving Picture and Associated Audio Information: Systems on pages viii - xii, incorporated herein as a reference. Some embodiments of the invention apply a Packet Identifier (PID). PID is a unique integer value that identifies elements in the transport stream (TS) such as tables, data, or the audio for a program. Some more detailed technical examples of PID can be found in the specification ISO/IEC 13818-1 Information Technology - Generic Coding of Moving Picture and Associated Audio Information: Systems on page 19.

Some embodiments of the invention apply a Program Association Table (PAT). Figure 1 shows an example of a PAT. A PAT provides the correspondence between a program number and the PID value of the Transport Stream (TS) packets which carry the component data. The program number is the numeric label associated with a program. Some more detailed technical examples of the PAT can be found in the specification ISO/IEC 13818-1 Information Technology - Generic Coding of Moving Picture and Associated Audio Information: Systems on page 41.

Some embodiments of the invention apply a Program Map Table (PMT). Figure 2 shows an example of a PMT. Each PMT literally maps out a specific program, listing the PID values for the packets containing the program's video, audio and data components. With this information, the decoder can easily discover, decode and display the program's contents. The Specification ISO/IEC 13818-1 Information Technology - Generic Coding of Moving Picture and Associated Audio Information: Systems provides some more detailed technical examples on the PMT on page 44. A component identifier 200 is an area of values declaring the PID which is used by Service Announcements. A value 0x90 of the component identifier 200 is only one example and other values can be applied.

In some further embodiments, the PMT also indicates the PID value for a program's Entitlement Control Message (ECM). The ECM supplies the decoder with the keys necessary to descramble the audio and video for a program.

Some of the embodiments of the invention applies a component identifier or alternatively expressed a streamjype_id bit field. Any value of stream_type_id not re- served for other defined purpose can advantageously be used to declare PID that is used by SA. Conventionally, stream_type_id is an 8 bit field specifying the type of program element carried within the packets associated with the PID. The specification ISO/IEC 13818-1 Information Technology - Generic Coding of Moving Pic- ture and Associated Audio Information: Systems provides some more detailed technical examples on stream_type_id field on page 45.

Fig. 3 has been described in the foregoing. In the following, corresponding reference signs have been applied to corresponding parts. Some embodiments of the invention apply the system of figure 3. A wireless terminal 306 operates preferably under the coverage of a digital broadcast network (DBN) 300. The wireless terminal 306 is capable of receiving IP based services that the DBN 300 is providing. The transmission of the DBN 300 comprises Transport Stream (TS). The DBN 300 comprises means for modifying the transport stream that it is transmitting. The DBN 300 provides a Program Association Table (PAT), which comprises a Packet Identifier (PID) that is allocated to a Program Map Table (PMT). The DBN 300 can enter service announcement (SA) parameters into a component identifier which is comprised in the PMT. The PMT is arranged to comprise a certain component identifier, such as stream_type_id indicating value 0x90 as described in the exam- pie of Figure 2. The component identifier declares the PID which is used by the SA. The SA comprises parameters based on which it is possible to map IP based services into physical and link layer parameters. The physical and link layer parameter comprises the parameter that the receiver requires for receiving IP based service, such as parameter transport_stream_id, PID, Medium Access Control (MAC) address, IP address, port, etc. The wireless terminal 306 receives the PAT and the PMT. The wireless terminal 306 can identify and obtain the SA from the component identifier. Therefore, the wireless terminal 306 can discover the certain IP based service that is defined in the SA parameters. Advantageously, the wireless terminal 306 does not require beforehand modification to such SA parameters but they can be taken care while receiving the broadcast transmission. Advantageously, the wireless terminal 306 does not require any interaction for discovering the service announcement. Therefore, the embodied invention is cost efficient. Still referring to figure 1 , the digital broadcast network (DBN) 300 transfers the data to the user wirelessly. Examples of the DBN 300 are a Digital Video Broadcasting (DVB) or alternatively Digital Audio Broadcasting (DAB) network configured to transfer data information. Advantageously, a terrestrial digital video broad- cast (DVB-T) network is applied in the invention. The DBN 300 comprises an ability to transfer data wirelessly. Before wireless transmission, the data is processed in the DBN 300. As is well known in the art, IP encapsulators 304 perform a multiprotocol encapsulation (MPE) and places the IP data into Moving Picture Experts Group-Transport Stream (MPEG-TS) based data containers. The encapsulators 304 perform the generation of the tables, the linking of the tables and the modification of the tables. Alternatively, a multiplexer of the DBN 300 can perform this. According to some embodiments, the operation of the IP encapsulators 304 may involve placing the received data into UDP packets, which are encapsulated within IP packets, which are in turn encapsulated into DVB packets. Details of this multi- protocol encapsulation technique may be found, for example, in standard document EN 301 192, incorporated herein as a reference. At the application layer, usable protocols include UHTTP (unidirectional HTTP), RTSP (Real-Time Streaming Protocol), RTP (Real-time Transport Protocol), SAD / SDP (Service Announcement Protocol / Service Description Protocol) and FTP.

In certain further embodiments, IP encapsulation may make use of IPSEC (Internet Protocol Security) to ensure that content will only be usable by receivers with the appropriate credentials. During the encapsulation process, a unique identifier may be added to at least one of the headers. For example, when UHTTP is used, the unique identifier may be encoded in the UHTTP header under the UUID field. Therefore in certain embodiments, to cater for the delivery of data to a particular terminal or group of terminals, the containers may also hold address information which can be identified and read by a conditional access component in the wireless terminal 306 to determine whether the data is intended for that terminal. Al- ternatively, to cater for the delivery of data to a plurality of terminals multicast can be applied, and advantageously single sender can reach multiple receivers. A Virtual Private Network (VPN) can also be formed in the system of the DBN 300, and the wireless terminal 306. A certain bandwidth of the DBN 300 broadcasting is al- located to a point-to-point or point-to-multipoint communication from the DBN 300 to the wireless terminal 306. The DBN 300 may also have various transmission channels for other streams running. The wireless terminal 300 performs a multiprotocol decapsulation to form the IP data packets.

The DVB packets so produced are transmitted over the DVB wireless link as is known in the art. The wireless terminal 306 receives digitally broadcast data. The wireless terminal 306 receives the PAT and the PMT. The wireless terminal 306 can identify and obtain the SA from the component identifier. Therefore, the wire- less terminal 306 can discover the certain IP based service that is defined in the SA parameters. The wireless terminal 306 can discover the service, and the user can consume the provided service using the wireless terminal 306. When a transmission rate is specified by the caster, that rate is adhered to.

Fig. 4 has been described in the foregoing. In the following, corresponding reference signs have been applied to corresponding parts. Some embodiments of the invention apply the table structures and relationship that are depicted in Figure 4. The Program Association Table 400 comprises a Packet Identifier (PID). The PID is allocated to a Program Map Table (PMT) 402. The PAT and the PMT are com- prised in the transmission stream where the service is also comprised. The PMT 402 comprises a component identifier such as stream_type_id, or a user private defined area, hexadecimal values 0x80 - OxFF. In the example of Figure 4, the value 0x90 is applied but other values are applicable as well. The stream_type_id declares the PID which is used by Service Announcements (SA) 404. The SA 404 comprises SA parameters that are transmitted in the transmission stream. The SA 404 is used to map IP-based services into the physical and link layer parameters. The parameters may comprise MPEG-2 level parameters and DVB-T modulation parameters, or when reviewing Open Systems Interconnection (OSI) model the two lower layers. For example, the SA 404 maps frequency, Medium Control Ac- cess (MAC) address, IP address, ports, etc.

Figure 5 depicts in a form of a flowchart a method for discovering service announcements (SA) in MPEG-TS using PAT and PMT tables in the digital broad- cast network in accordance with a further embodiment of the invention. Figure 3 shows an example of the Digital Broadcast Network (DBN) 300 operation in accordance with the further embodiment of the invention. In the DBN 300, the multiprotocol encapsulator (MPE) 304 is configured to perform the functions of the method. Alternatively, a multiplexer of the DBN can be applied. In step 500 Program Association Table (PAT) is generated. The PAT is generated by the IP encapsulators 304 in the DBN 300. The PAT comprises a Packet Identifier (PID). In step 502 the PAT is linked to a Program Map Table (PMT) by the IP encapsulators 304. The PID is allocated to the PMT so that the PID can identify the PMT. In step 504 the PMT is generated. The PMT defines a component identifier for a component that comprises service announcement. The PMT comprises the component identifier such as stream_type_id, or a user private defined area, hexadecimal values 0x80 - OxFF. The stream_type_id declares the PID which is used by Service Announcements (SA). For example, a value 0x90 is selected but some other val- ues are applicable as well. The SA is used to map IP-based services into the physical and link layer parameters. The parameters may comprise MPEG-2 level parameters and DVB-T modulation parameters, or when reviewing Open Systems Interconnection (OSI) model the two lower layers. For example, the SA maps Medium Control Access (MAC) address, IP address, ports, etc.

Figure 6 depicts in a form of a flowchart a method for discovering service announcements in MPEG-TS using PAT and PMT tables in the wireless terminal in accordance with a further embodiment of the invention. The wireless terminal 306 receives the transmission from the DBN 300. Operations in the example of Figure 6 are performed in the wireless terminal 306. In step 600, signal scanning is performed. The wireless terminal 306 scans signals in an appropriate frequency range, for example UHF. In condition 602, there is being checked whether an appropriate broadcast signal is available. If the appropriate broadcast signal is available, the wireless terminal 306 is able demodulate the signal using, for example Orthogonal Frequency Division Multiplexing (OFDM), modulation and can obtain wirelessly broadcasted possible channel and IP supply. Then, there is being checked whether there is MPEG-TS available in condition 604, so that the transmission from the DBN 300 to the wireless terminal 306 comprises the MPEG pro- tocol. If there is MPEG-TS available the wireless terminal 306 can identify tables. In condition 608, there is being checked whether the PAT is available among the broadcast transmission. The wireless terminal 306 can receive and identify the PAT from the TS. In condition 610, there is being checked whether the PMT is de- fined in the PAT. The PMT can be defined in the PAT, for example, in such a way that the PAT comprises the PID which is allocated to the PMT. Therefore, the PAT is linked to the PMT. In condition 612, there is being checked whether there is a component corresponding to a component identifier. The PMT defines a component identifier for a component that comprises a service announcement. For ex- ample, the PMT comprises streamjypejd, or a user private defined area, hexadecimal values 0x80 - OxFF. The stream_type_id declares the PID which is used by Service Announcements (SA). In the example of figure 6, a value 0x90 is selected but some other values are applicable as well. The SA is used to map IP- based services into the physical and link layer parameters. The parameters may comprise MPEG-2 level parameters and DVB-T modulation parameters, or when reviewing Open Systems Interconnection (OSI) model the two lower layers. For example, the SA maps Medium Control Access (MAC) address, IP address, ports, etc. In step 614, the wireless terminal 306 can create a filter for service announcement. Therefore, the wireless terminal 306 is able to obtain the SA from the transmission stream which contains a big number of other information. If any of the conditions are not met, the process ends in step 604. However, the process may continue if the wireless terminal 306 starts receiving the transmission stream again, for example, due to a carouselling or a re-transmission.

Figure 7 depicts an exemplary block diagram of a wireless terminal for discovering service announcements in MPEG-TS using PAT and PMT tables. The wireless terminal 306 of Fig. 7 may be used in the example of figure 3. The wireless terminal 306 comprises a processing unit CPU 703, a broadcast receiver part 705 and a user interface Ul (701, 702). The broadcast receiver part 705 and the user inter- face Ul (701 , 702) are coupled with the processing unit CPU 703. The user interface Ul (701 , 702) comprises a display and a keyboard to enable a user to use the wireless station 306. In addition, the user interface Ul (701 , 702) comprises a microphone and a speaker for receiving and producing audio signals. The user inter- face Ul (701 , 702) may also comprise voice recognition (not shown). The processing unit CPU 703 comprises a microprocessor (not shown), memory 704 and software SW (not shown). The software SW is stored in the memory 704. The microprocessor controls, on the basis of the software SW, the operation of the wireless terminal 306, such as the receiving of the stream, the discovering of the SA, displaying output in the user interface Ul and the reading of inputs received from the user interface Ul. The operations are described in the example of figure 6. For example, the software SW comprises means for identifying the signal, means for demodulation, means for identifying the stream, means for identifying and reading the tables, and means for receiving IP based services. Alternatively, is hardware or middleware implementation can be applied (not shown). The wireless terminal 306 can be a hand-held device which the user can comfortably carry. Advantageously, the wireless terminal 306 can be a cellular mobile phone which comprises the receiver 705 for receiving the transmission stream. Therefore, the wireless terminal can also interact with the service providers.

Because some embodiments of the inventions uses MPEG-2 defined Program Specific Information (PSI) tables, the invention provides compatible solutions for ATSC systems as well.

Particular implementations and embodiments of the invention have been described. It is clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented above, but that it can be implemented in other embodiments using equivalent means without deviating from the characteris- tics of the invention. The scope of the invention is only restricted by the attached patent claims.

Claims

1. A method for announcing of a service in a transmission stream that a digital broadcast network is transmitting, the method comprising: generating a first table and a second table, linking the first table with the second table, transmitting the first table and the second table to a wireless terminal via the digital broadcast network, receiving the first table at the wireless terminal, wherein the first table comprises an identifier of the second table, and identifying the second table in the transmission stream using the identifier, and identifying a component identifier in the second table, the component identifier identifying a component in the transmission stream, which compo- nent comprises parameters for the reception of the service.

2. The method according to claim 1 , wherein the first table comprises a Program Association Table (PAT).

3. The method according to claim 1 , wherein the second table comprises a Program Map Table (PMT).

4. The method according to claim 1 , wherein the digital broadcast network is one of a Digital Video Broadcasting (DVB) network, a network compliant for Advanced Television Systems Committee (ATSC) and a Digital Audio Broadcasting (DAB) network.

5. The method according to claim 1, wherein the digital broadcast network comprises a terrestrial digital video broadcasting (DVB-T) network.

6. The method according to claim 1 , wherein the identifier comprises a Packet Identifier (PID).

7. The method according to claim 1 , wherein the component comprises Service Announcements (SA).

8. The method according to claim 1 , wherein parameters for the reception of the service comprise at least two selected from the group of: trans- port_stream_id, PID, Medium Access Control (MAC) address, IP address, and port.

9. The method according to claim 1 , wherein the component identifier comprises stream_type_id.

10. The method according to claim 1 , wherein the component identifier comprises a certain value.

11. The method according to claim 1 , wherein the transmission stream comprises a transport stream.

12. A method in a transmission for announcing of a service in a transmission stream that a digital broadcast network is transmitting, the method comprising: generating a first table and a second table, linking the first table with the second table, and transmitting the first tables to a wireless terminal via the digital broadcast network, wherein the first table comprises an identifier of the second table, and the second table comprises a component, which component is tagged with a component identifier contained in the second table, the component comprising parameters for the reception of the service.

13. A method in a reception for discovering a service in a transmission stream that a digital broadcast network is transmitting, the method comprising: receiving a first table at a wireless terminal, wherein the first table comprises an identifier of a second table, and identifying the second table in the transmission stream using the identifier, and identifying a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.

14. A wireless terminal for discovering a service in a transmission stream that a digital broadcast network is transmitting, the wireless terminal comprising: means for receiving a first table at a wireless terminal, wherein the first table comprises an identifier of a second table, and means for identifying the second table in the transmission stream using the identifier, and means for identifying a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.

15. The wireless terminal according to claim 14, further comprising means for interaction with the digital broadcast network.

16. A system for announcing of a service in a transmission stream that a digital broadcast network is transmitting, the system comprising: means for generating a first table and a second table, means for linking the first table with the second table, and means for transmitting the tables to a wireless terminal via the digital broadcast network, wherein the first table comprises an identifier of the second table, and the second table comprises a component, which component is tagged with a component identifier contained in the second table, the component comprising parameters for the reception of the service.

17. The system according to claim 16, wherein means for generating and mapping the tables comprises a multi-protocol encapsulator.

18. The system according to claim 16, wherein means for generating and mapping the tables comprises a multiplexer of the digital broadcast network.

19. The system according to claim 16, wherein means for transmitting comprises at least one transmission station of the digital broadcast network.

20. The system according to claim 16, further comprising means for receiving the first table at a wireless terminal.

21. The system according to claim 20, further comprising means for discovering said parameters with the wireless terminal.

22. A computer program product comprising a program of instructions executable by a computing system for processing an announcement of a service in a transmission stream that a digital broadcast network is transmitting, the computer program product comprising: computer program code for causing the system to generate a first table and a second table, computer program code for causing the system to link the first table with the second table, computer program code for causing the system to transmit the tables to a wireless terminal via the digital broadcast network, computer program code for causing the system to receive the first table at the wireless terminal, wherein the first table comprises an identifier of the second table, computer program code for causing the system to identify the second table in the transmission stream using the identifier, and computer program code for causing the system to identify a component identifier in the second table, the component identifier identifying a component in the transmission stream, which component comprises parameters for the reception of the service.