Subnet-Aware Multicast Packet Forwarding in Wireless Networks

The patent segments the packet delivery process by introducing subnet-level matching as an intermediate layer between receiving multicast/broadcast packets and forwarding them to sessions. The user plane network element divides packets into different subnets based on subnet identifiers, then selectively forwards only to sessions within matching subnets. This segmentation prevents unnecessary network resource consumption by ensuring packets are delivered only to appropriate recipients.

The patent applies preliminary action by pre-establishing the correspondence between sessions and subnet identifiers before packet forwarding occurs. During session establishment or modification, the user plane network element stores the mapping between session identifiers and subnet identifiers in advance. When multicast or broadcast packets arrive, the system only needs to perform a simple lookup operation against this pre-built mapping table, significantly reducing the complexity of real-time packet processing while maintaining high delivery precision.

The patent makes the subnet identifier information multi-functional by storing it in a centralized correspondence table that serves multiple purposes: it enables accurate packet routing for multicast/broadcast traffic, supports session management operations, and provides subnet-based policy enforcement capabilities. This universal storage approach avoids redundant storage of subnet information in multiple locations, reducing overall information storage requirements while maintaining high routing accuracy.