Multicast Encapsulator for Uni-Directional DVB-T Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional IP multicasting is impractical over uni-directional wireless networks like DVB-T due to the inability to send join and leave messages, and the need for expensive DVB multiplexers and equipment for data transmission.
Innovation Solution
A node in a bi-directional network that can transmit join and leave messages unidirectionally, using an encapsulator and controller to manage multicast sessions, acting as a proxy client for mobile user equipment, and encapsulating multicast data for transmission over DVB-T systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional IP multicasting is used over uni-directional wireless networks, then data can be transmitted to mobile clients, but join and leave messages cannot be sent back to the network
Solution Approach 1:
The patent introduces a reflection point as an intermediary component in the network that reflects multicast data back to mobile clients. This intermediary enables the unidirectional link to function bidirectionally for control messages by reflecting the data stream, allowing clients to send join and leave messages without requiring complex network reorganization or additional communication paths.
2Ease of manufacture
If DVB multiplexers and equipment are used for data transmission, then IP data can be encapsulated and transmitted over DVB-T networks, but the cost of equipment and deployment increases significantly
Solution Approach 1:
The patent makes existing network infrastructure multi-functional by enabling it to handle both traditional multicast traffic and IP data encapsulation for mobile clients. The reflection point and network elements can serve multiple purposes: standard multicast routing, IP data transmission over unidirectional links, and control message handling, thereby eliminating the need for dedicated expensive DVB-specific equipment.
Solution Approach 2:
The system enables the existing network infrastructure to serve itself by implementing IP data encapsulation and transmission capabilities within current network elements. Rather than requiring separate specialized equipment, the existing routers and network components can perform the necessary functions through software or configuration changes, reducing equipment costs.
3Adaptability or versatility
If a separate multicast tree for control messages is implemented, then bi-directional communication can be achieved over uni-directional links, but significant reorganisation of network functionality is required
Solution Approach 1:
The patent segments the data stream at the reflection point, separating control messages from data traffic. By reflecting specific portions of the multicast stream back towards clients, the system creates bidirectional communication capability without requiring a completely separate control message tree. This segmentation approach maintains adaptability while minimizing the reorganization needed in network functionality.
Data Source
AI summary
IP data is multicast from one or more servers (4) in sessions through a network (N) comprising a plurality of routers (R) in a multicast tree to transmission sites (S) of a DVB-T network, where the data is encapsulated by IPEs 28 and transmitted uni-directionally to mobile user equipment (UE). A controller (38) builds up a schedule of session data concerning sessions transmitted by the servers (4) and instructs the IPEs to send join messages to receive data for selected sessions. The join messages may include the address of the source and may be transmitted in good time before the start of the session.