Single Buffer RLC Entity for Relay Node
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Solution Overview
Problem
Current wireless communications networks face challenges in supporting a wide range of devices, including low complexity IoT devices and wearable devices, due to issues such as high power consumption and processing load in relay devices, particularly when optimizing user-plane relaying operations at the RLC layer for LTE systems.
Innovation Solution
The implementation of a single buffer RLC entity for relay nodes, which combines reception and transmission buffers, and the use of independent RLC entities for each radio link, along with a method to trigger reporting of the relay transmission buffer status to the original transmitter, to reduce delay, processing overhead, and prevent protocol stalling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate reception and transmission buffers are used in relay nodes, then reliability of data forwarding is improved, but memory requirements and device complexity increase
Solution Approach 1:
The patent combines separate reception and transmission buffers into a single unified buffer structure at the relay node. This single buffer serves both reception and transmission functions, reducing memory requirements and simplifying the buffer management architecture while maintaining reliable data forwarding through proper protocol state tracking.
Solution Approach 2:
The single buffer at the relay node performs multiple functions - it stores both received data units from the transmitting node and prepares them for transmission to the receiving node. This multi-functional buffer design eliminates the need for separate buffer structures while supporting both reception and transmission operations.
2Reliability
If protocol data units are stored in buffer for relaying, then data forwarding reliability is improved, but processing overhead and delay increase
Solution Approach 1:
The relay node performs preliminary actions by pre-processing and storing protocol data units in the single buffer during idle periods or when buffer conditions permit. This allows the relay to have data ready for immediate transmission when opportunities arise, reducing actual transmission delay while maintaining reliability through advance preparation.
Solution Approach 2:
The buffer management system dynamically adjusts its behavior based on current conditions - it stores data units when capacity allows and processes/forwards them when transmission opportunities arise. This dynamic approach optimizes the balance between reliability (ensuring data is available) and delay (minimizing storage time).
3Adaptability or versatility
If relay node performs user-plane relaying operations at RLC layer, then communication flexibility is improved, but processing load and power consumption increase
Solution Approach 1:
The patent extracts and implements user-plane relaying functionality specifically at the RLC layer, separating this function from other protocol layers. By concentrating relaying operations at the appropriate layer (RLC), the system achieves communication flexibility where needed while avoiding unnecessary processing at other layers, thus reducing overall power consumption.
Solution Approach 2:
The relay node applies enhanced processing and buffer management specifically at the RLC layer where user-plane relaying is required, rather than uniformly across all protocol layers. This localized approach provides the necessary communication flexibility at the RLC layer while minimizing processing load and power consumption at other layers where full relaying functionality is not needed.
4Reliability
If transmission buffer status is continuously monitored and reported, then flow control reliability is improved, but processing overhead and signaling load increase
Solution Approach 1:
The relay node implements feedback mechanisms to monitor transmission buffer status and report when thresholds are exceeded. This feedback enables the transmitting node to adjust its data unit transmission rate, ensuring reliable flow control while avoiding the need for continuous monitoring and reporting - feedback is triggered only when necessary (e.g., when buffer exceeds threshold).
Solution Approach 2:
The system changes the monitoring parameter from continuous to event-driven, triggering buffer status reports only when specific conditions are met (such as buffer occupancy exceeding a predetermined threshold). This parameter change reduces processing overhead and signaling load while maintaining flow control reliability through timely feedback when needed.
Data Source
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AI summary
A communications device acting as a relay device is configured to communicate with a transmitting node operating with a mobile communications network and a receiving node operating with the mobile communications network. The communications device acting as the relay device comprises receiver circuitry configured to receive signals representing protocol data units formed from one or more service data units via a first wireless access interface from the transmitting node according to a first automatic repeat request process for transmission to the receiving node, transmitter circuitry configured to transmit signals representing the received protocol data units via a second wireless access interface to the receiving node according to a second automatic repeat request process, controller circuitry configured to control the transmitter circuitry to transmit the signals and to control the receiver circuitry to receive the signals to transmit, and a buffer configured to store the protocol data units received by the receiver circuitry for transmission to the receiving node according to the second automatic repeat request process. If the number of protocol data units or number of bytes stored in the buffer exceeds a predetermined threshold, the controller circuitry is configured in combination with the transmitter circuitry and the buffer to transmit to the transmitting node an indication that the number of protocol data units or the number of bytes stored in the buffer exceeds the predetermined threshold. In embodiments of the present technique, the transmitting node may be a communications device, or an infrastructure equipment. In embodiments of the present technique, the receiving node may be a communications device or an infrastructure equipment. In embodiments of the present technique, the buffer is a first buffer, the first buffer being a transmission buffer configured to receive the protocol data units formed from the one or more service data units received from the receiver circuitry for transmission to the receiving node according to the second automatic repeat request process from a second buffer, the second buffer being a reception buffer.