Access Point Multicast Grouping for Wireless Data Delivery
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Solution Overview
Problem
Existing data transmission methods, particularly in video-on-demand systems over wireless networks, face challenges in efficiently and reliably delivering data to multiple user devices with limited bandwidth and unreliable wireless connections, leading to increased data packet transmission requirements.
Innovation Solution
A method where an access point groups user devices into multicast groups based on their requests and cache contents, using forward error correction to encode and transmit file blocks, allowing devices to reconstruct missing data from cached blocks, thereby reducing the number of transmitted packets and enabling simultaneous transmission of multiple files.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If unicast transmission is used to ensure high transmission quality for each user device, then reliability is improved, but the number of transmitted data packets increases significantly
Solution Approach 1:
The patent combines multiple unicast transmissions into a single multicast transmission by grouping user devices and their requested file blocks into multicast groups. The access point transmits encoded file blocks to multiple users simultaneously over shared wireless links, reducing the total number of transmissions while maintaining reliability through FEC coding.
Solution Approach 2:
The multicast transmission mechanism serves multiple user devices with different file block requests simultaneously. A single encoded transmission can satisfy multiple users' needs, making the transmission system universal rather than dedicated to individual users.
2Reliability
If FEC coding is applied to each individual data stream to ensure high transmission quality, then reliability is improved, but the complexity of the transmission system increases
Solution Approach 1:
Instead of applying FEC coding to multiple separate unicast streams, the patent applies FEC coding once to the combined set of file blocks for each multicast group. This single coding operation serves multiple users simultaneously, reducing computational complexity while maintaining the same level of transmission reliability.
3Productivity
If multiple files are transmitted simultaneously to multiple user devices, then productivity is improved, but the number of required data packets increases
Solution Approach 1:
The patent merges transmissions of multiple files to multiple users into unified multicast groups. File blocks from different files are grouped together and transmitted simultaneously in single encoded packets, enabling efficient parallel delivery of multiple files while minimizing the total packet count.
Data Source
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AI summary
The invention relates to a method which is implemented by an access point, and in which requests are received from a number of user devices, wherein each of the requests specifies one or more requested file blocks of at least one file. A set of multicast groups is determined on the basis of the received requests, wherein each multicast group contains a set of indices of one or more of the user devices and a set of indices of the file blocks which are to be transmitted to the user devices indicated in the multicast group. For each multicast group of the set the file blocks indicated in the multicast group are retrieved and encoded, wherein a forward error correction process is used. For each of the multicast groups of the set the encoded file blocks indicated in the multicast group are transmitted to the user devices indicated in the multicast group. The invention further relates to methods and to access points, to user devices, and to machine-readable media.