LTE eMBMS Multicast Bearer for Group Communication Continuity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Push-to-Talk over Cellular (PoC) services in LTE networks face challenges with bursty downlink traffic causing network congestion, long call setup times, and service interruptions during handovers, particularly in large group communications.
Innovation Solution
Implementing Multimedia Broadcast and Multicast Service (eMBMS) in LTE networks for efficient radio resource utilization, supporting PoC downlink traffic multicasting, and enabling seamless handovers through dynamic scheduling and cell-multicasting schemes, along with RRC_IDLE mode reception for power saving and reduced latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PoC downlink traffic is transmitted using traditional multi-unicasting, then each user can receive traffic independently, but network congestion occurs and radio resource utilization is inefficient
Solution Approach 1:
The patent merges multiple unicast traffic streams into a single multicast transmission by establishing a multicast bearer that carries PoC downlink traffic for multiple users simultaneously. The eNodeB multiplexes traffic from multiple sources and delivers it efficiently to multiple UEs through the multicast channel, reducing redundant transmissions and optimizing radio resource utilization.
2Ease of operation
If traditional PoC service is used, then group communication is enabled, but call setup time is long
Solution Approach 1:
The patent applies preliminary action by pre-establishing a multicast bearer before actual PoC traffic needs to be transmitted. The network prepares the multicast channel and configures necessary resources in advance, allowing users to join groups and receive traffic immediately without long setup delays. This pre-configuration enables rapid service activation while maintaining reliability.
3Productivity
If MBMS bearer is established for PoC traffic, then efficient multicast transmission is achieved, but service interruption may occur during handover
Solution Approach 1:
The patent implements feedback mechanisms where the eNodeB monitors UE location and handover events in real-time. When a UE performs handover, the network receives feedback about the new location and dynamically adjusts the multicast bearer configuration accordingly. This feedback loop ensures continuous service by adapting the multicast transmission to maintain optimal delivery conditions during mobility.
4Reliability
If unicast bearer is used for PoC traffic, then service continuity is maintained, but network capacity drops and congestion increases
Solution Approach 1:
The patent segments the PoC downlink traffic delivery into two parts: a multicast bearer for efficient group transmission and a unicast bearer for individual user communication. The multicast component handles the bulk of group traffic to preserve network capacity, while the unicast component manages individual user needs and handover scenarios, achieving both efficiency and continuity.
Data Source
AI summary
A method of supporting group communication over LTE MBMS is provided. A UE first establishes a unicast bearer in a network for group communication. The UE belongs to a communication group having a communication group ID. The UE receives access information from the network for monitoring downlink (DL) multicast traffic of the DL group communication based on a multicast decision. The UE is then ready for monitoring a multicast Multimedia Broadcast Multicast Service (MBMS) bearer for receiving the DL multicast traffic. In one embodiment, The UE requests to switch the DL multicast traffic from the multicast MBMS bearer to the unicast bearer upon detecting that the UE is approaching an MBMS coverage boundary. In another embodiment, the UE transmits an indication of preferred target cells to the network before performing a handover and thereby maintaining multicast service continuity of the group communication.