Two-Step RACH With Combined Preamble-Payload Messaging
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Solution Overview
Problem
Existing wireless communication systems face latency issues in the random access procedure, particularly in 4G and 5G networks, as they rely on a 4-step process that is not optimized for faster and newer communication needs.
Innovation Solution
Implementing a 2-step random access channel (RACH) procedure where a UE transmits both a preamble and a payload in a single message, with the base station responding in a second message, optimizing the mapping of transmission resources and including contention resolution information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a 4-step random access procedure is used, then the random access process is completed with separate message exchanges, but the latency is high and communication efficiency is reduced
Solution Approach 1:
The patent combines the preamble transmission and payload transmission into a single message (Message 1), and combines the random access response and contention resolution into a single message (Message 2). This merging of multiple functions into fewer messages directly reduces the number of round-trip exchanges from 4 to 2, thereby reducing latency and improving communication efficiency during the random access procedure.
2Productivity
If a 2-step random access procedure is implemented, then latency is reduced and communication efficiency is improved, but the mapping of transmission resources becomes more complex
Solution Approach 1:
The patent segments the transmission resources into distinct types: RACH occasions for preamble transmission, payload transmission occasions for data transmission, and response windows for receiving acknowledgments. By segmenting and clearly defining these resource types, the system manages the complexity of 2-step random access resource mapping through structured organization rather than monolithic resource allocation.
3Loss of time
If preamble and payload are transmitted in a single message, then the random access process is accelerated, but the message structure becomes more complex
Solution Approach 1:
The patent segments Message 1 into distinct components: a preamble portion for random access initiation and a payload portion for data transmission. Similarly, Message 2 is segmented into a random access response portion and a contention resolution portion. This segmentation allows the complex combined message to be structured and processed in manageable, functionally-distinct parts, reducing the practical complexity despite the accelerated process.
Data Source
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AI summary
Methods, apparatus and systems for performing a random access procedure in a wireless communication are disclosed. In one embodiment, a method performed by a wireless communication node is disclosed. The method comprises: receiving, from a wireless communication device, a first message comprising a preamble and a payload for an access to the wireless communication node; and transmitting, to the wireless communication device, a second message in response to the first message.