Linear Cellular Network Handover Extension via Frequency Division
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In linear cellular networks, the fast movement of user terminals poses a challenge for handover procedures, as the time available for a seamless transition between nodes is extremely limited, potentially leading to communication interruptions critical for safety in transportation systems.
Innovation Solution
The system extends the handover area by configuring nodes to communicate over a downlink channel with allocated subsets of channel resources, allowing data mirroring between nodes to maintain communication beyond the traditional overlap area, thereby prolonging the handover time and ensuring stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nodes are aligned to create overlapping coverage areas for handover, then communication continuity is enabled, but the handover area is too small for fast-moving terminals
Solution Approach 1:
The patent extends the handover area by utilizing frequency resources as an additional dimension. Instead of only relying on spatial overlap of coverage areas, the system uses frequency division to create virtual extension of the handover region. The target node transmits data in frequency resources allocated to the source node, effectively expanding the handover area along the frequency dimension to accommodate fast-moving terminals.
2Device complexity
If coverage areas overlap only in a small area, then node density is reduced, but handover time becomes insufficient for fast terminals
Solution Approach 1:
The patent implements preliminary action by having the target node receive and prepare data in advance before the terminal actually enters the overlap area. The target node proactively transmits data in the source node's frequency resources while the terminal is still being served by the source node, ensuring that handover can occur seamlessly without waiting for the terminal to reach the traditional handover boundary.
3Area of stationary object
If additional hardware like repeaters is deployed to extend coverage, then coverage area is enhanced, but system complexity and cost increase
Solution Approach 1:
The patent uses copying by having the target node transmit copies of data in the source node's frequency resources. Instead of deploying physical repeaters or additional hardware, the system creates virtual copies of the data transmission using available frequency resources, effectively extending coverage and handover area through software-controlled resource allocation rather than additional hardware.
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a system (1) comprising a first and a second node (21, 22) of a linear cellular network, the first node (21) having a first antenna (71) for wirelessly communicating with a user terminal (4), wherein a scheduler (111) of the first node (21) is configured to allocate a first subset (s1) of all available channel resources (CRi) of a downlink communication channel, a scheduler (112) of the second node (22) is configured to allocate a second subset (s2) comprising the remaining available channel resources (CRi), and the second node is configured to communicate received data (3) in the first subset (s1) of channel resources (CRi) to a user terminal (4) when the user terminal (4) is located within the second coverage area (92) but outside the overlap area (10) to extend the area available for a handover. The invention also provides for a system (1) to extend the area available for a handover for an uplink communication channel.