MAC Management Response Reliability via Robust Modulation
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Solution Overview
Problem
In wireless communication systems, the unreliable transmission of Media Access Control (MAC) management messages from a base station to a mobile station can lead to operational mode desynchronization, resulting in throughput loss or call drops, especially when the mobile station fails to receive response messages.
Innovation Solution
The method involves transmitting MAC management responses using a more robust modulation and coding scheme than regular data bursts, with the level of robustness adjusted to achieve a predefined target error rate lower than the reported Carrier-to-Interference-Plus-Noise Ratio (CINR), and retransmitting until successful receipt, to enhance transmission reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a standard modulation and coding scheme is used for data bursts, then bandwidth efficiency is improved, but transmission reliability of MAC management messages deteriorates
Solution Approach 1:
The patent applies different modulation and coding schemes to different types of data bursts. MAC management messages use a more robust MCS (first MCS) while regular data bursts use a standard MCS (second MCS). This local differentiation ensures high reliability for control messages without sacrificing bandwidth efficiency for data traffic.
Solution Approach 2:
The system dynamically adjusts the modulation and coding scheme parameters based on the message type and channel conditions. The base station selects between multiple MCS levels (first MCS for robustness, second MCS for efficiency) and can adapt the robustness level to achieve a predefined target error rate, optimizing the trade-off between reliability and efficiency.
2Reliability
If a more robust modulation and coding scheme is used for MAC management messages, then transmission reliability is improved, but bandwidth overhead increases
Solution Approach 1:
The patent differentiates the quality level of modulation and coding schemes based on message importance. Only MAC management messages receive enhanced robustness, while data bursts use standard schemes. This localized approach minimizes bandwidth overhead by applying high robustness only where necessary.
Solution Approach 2:
The system uses a slightly excessive robustness level for MAC management messages to ensure reliable transmission even under poor channel conditions. The robustness level is set to achieve a predefined target error rate lower than the reported CINR, providing a margin of safety that justifies the minor bandwidth cost.
3Reliability
If retransmission is implemented until successful receipt, then transmission reliability is improved, but transmission time increases
Solution Approach 1:
The base station uses channel state information (CINR reports from the mobile station) to preliminarily select an appropriate robust MCS before transmission. This preliminary action reduces the need for retransmissions by ensuring the initial transmission has high reliability, thereby minimizing time loss.
Solution Approach 2:
The system implements feedback mechanisms where the mobile station reports its CINR to the base station, and the base station adjusts the MCS accordingly. This feedback loop enables adaptive modulation and coding that reduces transmission failures and minimizes retransmission time.
Data Source
AI summary
Certain embodiments of the present disclosure improve a robustness of some critical MAC management response massages transmitted from a base station (BS) to a mobile station (MS). In this way, a reliability of transmission can be increased and a messaging failure that results in out of sync state between the MS and the BS can be avoided.