Dynamic Bitmap Configuration for VoIP Packet Acknowledgment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional block ACK schemes in mobile communication systems, particularly in VoIP services, result in increased transmission delay and deteriorated speech quality due to the acknowledgment of reception results, which is inefficient for real-time services where packet loss is less critical than delay time.
Innovation Solution
A method is introduced to configure and transmit bitmaps based on packet error rates and intervals between errors, allowing for flexible adjustment of reception result reporting, assuming lost packets have been successfully received within user-defined conditions, thereby reducing retransmissions and minimizing transmission delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional block ACK scheme is used to acknowledge reception results, then reliability of packet delivery is improved, but transmission delay increases and speech quality deteriorates in real-time services
Solution Approach 1:
The patent dynamically adjusts the bitmap configuration based on packet error rates and intervals between errors. When packet error rates are low and intervals between errors are large, the system assumes lost packets were successfully received, reducing retransmissions. This dynamic adaptation resolves the contradiction by making the acknowledgment mechanism flexible rather than static, allowing it to optimize between reliability and delay based on current channel conditions.
Solution Approach 2:
The patent changes key parameters including the bitmap configuration (which packets to acknowledge), packet error rate thresholds, and interval between errors. By varying these parameters based on channel conditions, the system can reduce unnecessary retransmissions in good conditions (reducing delay) while maintaining adequate reliability when conditions deteriorate.
2Productivity
If block ACK message is transmitted to acknowledge multiple packets, then network efficiency is improved, but system load increases due to additional messaging
Solution Approach 1:
The patent applies partial action by selectively acknowledging only necessary packets in the bitmap. Instead of always acknowledging all packets in a block, the system uses error rate and interval information to determine which packets truly need acknowledgment, reducing unnecessary messaging overhead while maintaining network efficiency.
3Reliability
If retransmission is performed for every lost packet, then reliability is improved, but transmission delay increases and system load increases
Solution Approach 1:
The system uses self-service by leveraging the receiver's local knowledge of packet error rates and error intervals to make intelligent decisions about which packets need retransmission. Instead of blindly retransmitting all potentially lost packets, the receiver autonomously determines which packets are likely lost and requests only those, reducing unnecessary retransmissions and associated delays.
Data Source
AI summary
Disclosed is a method for configuring a bitmap in a mobile communication system employing a block ACK scheme, which faithfully performs its intrinsic function of acknowledging a reception result, and yet can reduce transmission delay and the overall system load due to retransmission in the case where packet loss is relatively less important than transmission delay time, such as in the case of voice communication. To this end, a recipient compares a PER of a received packet signal with a threshold value. If the PER is higher than the threshold value, the recipient operates in the block ACK scheme, and if the PER is lower than the threshold value, the recipient determines a bitmap configuration scheme on the assumption that an erroneous frame has been successfully received. Also, using the determined bitmap configuration scheme, the recipient transmits a reception result for each received packet.