Centralized Transport Control for 3GPP LTE Network Efficiency

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Solution Overview

Problem

The existing LTE network architecture faces challenges with increasing cell density and mobility events, leading to complex and error-prone user context transfers between eNBs, which results in dropped calls or sessions, and strains network resources, particularly with the lack of protocol or transport specified for decoupling PDCP and RLC functions from the eNB entity.

Innovation Solution

A server manages transport functions for multiple eNBs over a shared network, decoupling PDCP and RLC functions, using enhanced protocols like GTPv1-U and S1AP for packet transmission, and integrating mobility management and data plane security to centralize control and transport functions, reducing the burden on individual eNBs and enhancing network efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If PDCP and RLC functions are distributed in each eNB entity, then each eNB can independently manage its cells, but the complexity of user context transfers between eNBs increases and reliability decreases

Engineering Contradiction:
ImproveIndependent eNB management capabilityVSAvoidUser session continuity during handover
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts PDCP and RLC functions from individual eNB entities and consolidates them into a centralized transport network. This separation allows eNBs to focus on basic radio access functions while the centralized network handles complex protocol processing, thereby reducing handover complexity and improving session continuity reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a centralized transport network as an intermediary between eNBs, which manages user context transfers and protocol processing. This intermediary absorbs the complexity of inter-eNB coordination, allowing seamless handovers without requiring complex direct interactions between eNBs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the number of cells per eNB is limited to a small number, then each eNB can manage its functions effectively, but the network cannot scale to support high cell density

Engineering Contradiction:
ImproveNetwork scalabilityVSAvoideNB functional complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the network into distributed eNB entities that handle simple radio access functions and a centralized transport network that handles complex protocol processing. This segmentation allows individual eNBs to remain simple while the network as a whole achieves high scalability through the centralized coordination layer.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If complex hand-off signaling protocols are implemented between eNBs, then mobility management is achieved, but the system becomes error-prone and difficult to maintain

Engineering Contradiction:
ImproveMobility management capabilityVSAvoidInter-eNB signaling complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts complex hand-off signaling protocols from the eNB-to-eNB interface and relocates them to the centralized transport network. This extraction simplifies eNB operations while maintaining full mobility management capability through the centralized controller that handles all inter-eNB coordination.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2856837B1Pooled transport and control functions in a 3GPP LTE network
Publication Date: 2019.07.10 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2856837B1 patent drawingFigure 1
  • EP2856837B1 patent drawingFigure 2
  • EP2856837B1 patent drawingFigure 3

AI summary

Presented are methods and apparatus for decoupling transport and control (T&C) functions from a plurality of e NBs and collecting the T&C functions in a centralized entity for managing the T&C functions for a larger pool of e NBs. An enhanced interface and protocol is defined for allowing the new T&C pool entity to communicate with the e NBs over a shared IP based network. The redistributed functionality provides for optimizing both data compression capabilities and security by compressing data earlier in its transmission path and by encrypting data before it is sent to an e NB.