MBMS Synchronization Offset Adjustment for Wireless Delay Reduction
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Solution Overview
Problem
The existing wireless communication systems, particularly those supporting Multimedia Broadcast/Multicast Service (MBMS) in LTE systems, experience significant delays in data transmission due to the limitations of the MCCH modification period, leading to synchronization issues and quality of service degradation in broadcast services such as live video and voice transmissions.
Innovation Solution
A method is introduced to reduce data transmission delays by determining the eNB with the longest packet delay, calculating a new offset for the system frame number, and adjusting the offset value to synchronize data transmission across cells, thereby minimizing packet loss and ensuring timely delivery of broadcast data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the MCCH modification period is used for synchronization in MBMS transmission, then synchronization between eNBs is improved, but transmission delay increases significantly (up to 5.12 seconds or more)
Solution Approach 1:
The patent applies preliminary action by having the eNB determine the transmission time of the first packet in advance and communicate this timing information to the BMSC before actual data transmission begins. This allows the BMSC to pre-process and prepare data packets according to the predetermined timing, eliminating the need to wait for the MCCH modification period to expire before transmission can start, thus reducing the initial transmission delay while maintaining synchronization.
Solution Approach 2:
The patent implements feedback by establishing a communication loop where the eNB reports its determined transmission timing to the BMSC, and the BMSC adjusts its packet transmission schedule based on this feedback. This closed-loop feedback mechanism ensures that the BMSC can synchronize its data transmission with the eNB's transmission plan, maintaining synchronization between eNBs while avoiding the fixed delay imposed by the MCCH modification period.
2Stability of the object's composition
If the MCCH modification period is set to the standard minimum (5.12 seconds), then system stability is maintained, but real-time broadcast quality deteriorates
Solution Approach 1:
The patent applies preliminary action by having the eNB determine and communicate its transmission timing to the BMSC in advance, before the MCCH modification period expires. This allows the system to prepare for transmission ahead of time, enabling real-time broadcast quality improvement without reducing the MCCH modification period below the standard minimum, thus maintaining system stability while enhancing real-time performance.
3Stability of the object's composition
If data transmission waits for MCCH modification period completion, then synchronization is ensured, but packet delay increases causing quality of service degradation
Solution Approach 1:
The patent applies preliminary action by having the eNB determine its first packet transmission time in advance and communicate this to the BMSC before the MCCH modification period completes. This allows the BMSC to prepare data packets according to the predetermined timing, ensuring synchronization is maintained while eliminating the wait time that currently causes packet delay and quality of service degradation.
Solution Approach 2:
The patent implements feedback by establishing a communication loop where the eNB reports its determined transmission timing to the BMSC, and the BMSC adjusts its packet transmission schedule based on this feedback. This ensures synchronization is maintained while preventing the packet delays that degrade quality of service.
Data Source
AI summary
A method and an apparatus are provided for reducing a delay in a wireless communication system supporting a broadcast service. A message including last timestamp information is received from one or more eNBs in a broadcast service area. An eNB is determined that has received a packet with a longest delay, among the one or more eNBs based on the last timestamp information. A new offset of a system frame number is determined using the last timestamp information of the eNB. The new offset of the system frame number is transmitted to the one or more eNBs.