ProSe Buffer Status Report Handling in D2D Resource Allocation
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Solution Overview
Problem
In 3GPP LTE compliant communications systems, device-to-device (D2D) buffer status reports (BSRs) and scheduling requests (SRs) face ambiguities in contention resolution, particularly when proximity services (ProSe) BSRs are involved, leading to inefficient handling and resource allocation.
Innovation Solution
A method and system for transmitting ProSe BSRs and SRs, where a user device sends a message to a communications controller, receives a D2D resource grant, and cancels pending ProSe BSRs, ensuring clear resource allocation and contention resolution by distinguishing between cellular and D2D resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ProSe BSR is sent in MSG3 during random access procedure, then D2D resource allocation can be requested, but ambiguity arises in contention resolution between cellular and D2D resources
Solution Approach 1:
The patent segments the resource allocation process into two distinct parts: cellular resources for control signaling and D2D resources for device-to-device data transmission. By separating these resource types and their corresponding BSR handling, the patent eliminates ambiguity in contention resolution while maintaining both cellular and D2D communication capabilities.
2Loss of information
If pending ProSe BSRs are not canceled after resource grant, then buffer status information may be lost, but resource allocation efficiency decreases
Solution Approach 1:
The patent implements a feedback mechanism where the eNB sends an explicit cancellation indication in the uplink grant message to the UE. This feedback loop ensures that pending ProSe BSRs are properly canceled after successful resource allocation, preventing information loss while maintaining efficient resource utilization by avoiding redundant BSR transmissions.
Data Source
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AI summary
A method for device-to-device (D2D) communications by a user device includes transmitting a first message including a proximity services (ProSe) buffer status report (BSR) to a communications controller, receiving a second message including information regarding a D2D resource grant scheduled for the user device by the communications controller, and canceling all pending ProSe BSRs in accordance with the D2D resource grant.