Ip multicast service over a broadcast channel

• US 20050044142A1
• Filed: 09/11/2002
• Published: 02/24/2005
• Est. Priority Date: 09/28/2001
• Status: Abandoned Application

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Lefevre, Fabienne, Garrec, David, Benali, Amor
• Application Number:
  US10/491,057
• Publication Number:
  US 20050044142A1
• Time in Patent Office: Days
• US Class Current: 709/204
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04N 21/6112 involving terrestrial transmission, e.g. DVB-T
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/64723 Monitoring of network processes or resources, e.g. monitoring of network load traffic related reporting in data switching networks H04L43/062
• CPC Class Codes: H04N 21/6583 Acknowledgement
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/08 User group management

Abstract

A method of and apparatus for providing an Internet Protocol multicast service wherein multicast data is transmitted through multicast routers (8) to user stations (9) over a digital broadcast channel (especially DVB-T) together with digital broadcast signals, at least if a request has been received from a user station (9) for the multicast data,. The transmission of the multicast data by a multicast router is conditional upon the reception of a request for said multicast data from that multicast router by a plurality of the user stations (9). The number of requests from the user stations (9) has to be greater than a threshold number, which is a function of the available bandwidth for multicast transmission over the broadcast channel. Information concerning the requests for the multicast data by the user stations (9) is unavailable to the other user stations (9).

Claims

1. A method of providing an Internet Protocol multicast service wherein multicast data is transmitted through multicast routers (8) to user stations (9) over a digital broadcast channel together with digital broadcast signals, at least if a request (18) has been received from a user station (9) for the multicast data,

characterised in that the transmission of said multicast data (22) by said multicast routers is conditional upon the reception of said request (18) for said multicast data at said multicast routers from a plurality of said user stations (9).

2. A method as claimed in claim 1, wherein the transmission of said multicast data (22) by said multicast router is conditional upon the reception of a number of said requests (18) from said user stations (9) greater than a threshold number, said threshold number being a function of the available bandwidth for multicast transmission over said broadcast channel.

3. A method as claimed in claim 1 or 2, wherein said user stations (9) are repeatedly interrogated and the continued transmission of said multicast data (22) by said multicast router is conditional upon the reception of responses (18) from a plurality of said user stations (9).

4. A method as claimed in any preceding claim, wherein information concerning said requests (18) for said multicast data from said user stations (9) is unavailable to the others of said user stations (9).

5. A method as claimed in any preceding claim, wherein said signals and data are transmitted through gateways (6) between Internet and broadcast infrastructures (4, 5 and 10) to respective broadcast areas and the transmission of said multicast data (22) within a broadcast area by the corresponding gateway (6) is conditional upon the reception at that gateway of said request (18) for said multicast data from a plurality of said user stations (9) served by said broadcast area.

6. A method as claimed in any preceding claim, wherein announcements (17) of future multicast data transmission sessions are transmitted to said user