MAC Signaling for Direct Device-to-Device Communications
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Solution Overview
Problem
Current wireless communication systems face challenges in enabling direct device-to-device communication without network control, which can cause interference and require continuous network involvement, limiting the potential of proximity-based applications and offloading network traffic.
Innovation Solution
The system allows for direct medium access control (MAC) message transmission between user equipment (UE) devices, including control information for inter-device sessions, using inter-device session radio network temporary identifiers (IDS-RNTI) and resource allocation, enabling UE-to-UE communication while maintaining network control and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If direct device-to-device communication is enabled without network control, then communication efficiency and autonomy are improved, but interference to other mobile devices increases
Solution Approach 1:
The patent introduces a base station as an intermediary that provides semi-persistent scheduling control for D2D communications. The base station allocates resources and sends scheduling commands to UE1, enabling direct communication while maintaining network control to prevent interference to other devices.
Solution Approach 2:
The patent changes the operational parameters of D2D communication from completely autonomous to semi-persistent scheduling mode. The base station configures scheduling parameters (resource allocation, timing, frequency) that remain persistent across multiple transmissions, balancing autonomy with network control to reduce interference.
2Object-affected harmful factors
If continuous network involvement is maintained for D2D communication, then interference control is improved, but communication autonomy and offloading capability deteriorate
Solution Approach 1:
The patent implements semi-persistent scheduling where the base station performs periodic control actions rather than continuous control. The base station sends scheduling commands at specific intervals and maintains persistent resource allocations, reducing network involvement while preserving interference control capability.
Solution Approach 2:
The base station performs preliminary resource allocation and scheduling configuration before D2D communication begins. This preliminary action establishes persistent resource allocations that enable autonomous communication while pre-configured interference control measures remain in place.
3Productivity
If autonomous D2D communication is fully enabled, then network offloading capability is improved, but network control and interference management worsen
Solution Approach 1:
The patent segments the control function into two parts: semi-persistent scheduling control remains with the base station for interference management, while actual data transmission and MAC layer operations are autonomous at the UE level. This segmentation enables offloading while maintaining necessary network control.
Solution Approach 2:
The UEs perform self-service in terms of autonomous MAC message transmission and data exchange using pre-configured resources. The devices independently manage their communications without continuous network intervention, achieving offloading while the base station maintains overall resource coordination.
Data Source
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AI summary
A method performed at a first user equipment, UE, of a wireless communications network, the method comprising receiving, by the first UE from a base station, configuration information for the first UE to establish an inter-device session, IDS, between the first UE and a second UE, the configuration information including a first IDS radio network temporary identifier, IDS-RNTI, transmitting, by the first UE, a medium access control, MAC, message to the base station, the MAC message comprising a buffer status report, BSR control element, CE, the BSR MAC CE indicating a total amount of data available to be transmitted across a plurality of logical channels of a logical channel group associated with the IDS between the first UE and the second UE, receiving, by the first UE from the base station, a control message addressed to the first IDS-RNTI, the control message comprising a radio resource identifier, the radio resource identifier indicating a radio resource to be used for transmitting data directly from the first UE to the second UE, and the control message further comprising a resource for an IDS Transmit Control Channel, IDS-TxCCH, for transmission parameter indication with respect to the IDS between the first UE and the second UE, transmitting the data by the first UE over the IDS session using the radio resource indicated by the radio resource identifier and transmitting by the first UE to the second UE a transmission parameter using the indicated IDS-TxCCH resource, wherein the transmission parameter indicates a change in a Modulation and Coding Scheme, MCS, of the IDS session.