Network Node Random Access Preamble Collision Reduction
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Solution Overview
Problem
In wireless communication systems, random access procedures in cellular networks face challenges such as preamble collisions during high network access loads, leading to increased radio resource consumption, delayed access, and energy consumption, particularly exacerbated by the emergence of numerous machine-type communication devices.
Innovation Solution
A method and system where a network node differentiates wireless devices using their System Architecture Evolution (SAE) Temporary Mobile Subscriber Identity (S-TMSI) to allocate resources, allowing for efficient contention resolution and reducing preamble collisions by using pre-allocated Cell-Radio Network Temporary Identifiers (C-RNTIs) for known devices, thereby optimizing PRACH capacity and reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless devices use random access preambles to initiate network access, then network access capability is improved, but preamble collisions occur leading to increased access delay and failed attempts
Solution Approach 1:
The network node maintains a history of previously connected wireless devices and their identifiers. Before processing random access requests, the node checks this history to identify known devices and allocate dedicated resources in advance, avoiding the need for these devices to go through the standard random access procedure and thereby eliminating access delays.
Solution Approach 2:
The patent introduces an intermediary mechanism (history storage and identification system) that mediates between wireless devices and the random access procedure. By identifying devices through their S-TMSI in the random access preamble or subsequent messages, the system can redirect known devices to dedicated resources, effectively mediating the conflict between random access and resource allocation.
2Productivity
If more random access resources are allocated to handle high network loads, then network capacity is improved, but radio resource consumption increases
Solution Approach 1:
The patent applies local quality by differentiating resource allocation based on device characteristics. Known devices (identified through S-TMSI matching) receive dedicated time-frequency resources, while unknown devices use the standard random access preamble resources. This localized differentiation optimizes resource usage by allocating resources only where needed rather than uniformly across all devices.
Solution Approach 2:
The system dynamically adjusts resource allocation based on real-time identification of wireless devices. When a random access request is received, the node checks the history to determine if the device is known, and then dynamically assigns either dedicated resources or standard random access resources accordingly. This dynamic adaptation allows the system to handle varying network loads efficiently without over-provisioning resources.
3Reliability
If wireless devices restart the random access procedure after failure, then access attempt is resumed, but radio resource consumption and energy consumption increase
Solution Approach 1:
The network node performs preliminary identification of wireless devices by checking their S-TMSI against the stored history before the random access procedure completes. This preliminary action allows the system to recognize known devices early and allocate dedicated resources for subsequent communication, preventing access failures that would require restarts and the associated energy consumption.
Data Source
AI summary
A network node, a wireless device and methods performed thereby for use in a Random Access, RA, procedure with wireless devices in a cell of the network node are provided. The method includes receiving, from at least two wireless devices, a RA message comprising an RA preamble; transmitting an RA Response, RAR, to the at least two wireless devices, the RAR comprising a TC-RNTI and an RA preamble identifier identifying the received RA preamble; and receiving, from each of said at least two wireless devices, a connection request message comprising a respective S-TMSI. The method includes for a wireless device previously connected to the network node in the same cell, transmitting a connection setup message addressed to a C-RNTI previously assigned to the wireless device; and for a wireless device not previously connected to the network node in the same cell, transmitting, a connection setup message addressed to the TC-RNTI.