[Paper Review] E2E Migration Strategies Towards 5G: Long-term Migration Plan and Evolution Roadmap

Abolfazl Zakeri, Narges Gholipoor+5 more|arXiv (Cornell University)|Feb 20, 2020

Telecommunications and Broadcasting Technologies4 citations

TL;DR

This paper proposes a comprehensive end-to-end (E2E) migration framework for 5G evolution, addressing long-term deployment strategies across radio access, transport, and core networks. It outlines phased migration paths based on technical, cost, and standardization factors, with a vision for 5G evolution (E5G) through 3GPP Releases 18–20, enabling future-proof, scalable, and interoperable network transitions for CSPs.

ABSTRACT

After freezing the first phase of the fifth generation of wireless networks (5G) standardization, it finally goes live now and the rollout of the commercial launch (most in fixed 5G broadband services) and migration has been started. However, some challenges are arising in the deployment, integration of each technology, and the interoperability in the network of the communication service providers (CSPs). At the same time, the evolution of 5G is not clear and many questions arise such as whether 5G has long-term evolution or when 5G will change to a next-generation one. This paper provides long-term migration options and paths towards 5G considering many key factors such as the cost, local/national data traffic, marketing, and the standardization trends in the radio access network (RAN), the transport network (TN), the core network (CN), and E2E network. Moreover, we outline some 5G evolution road maps emphasizing on the technologies, standards, and service time lines. The proposed migration paths can be the answer to some CSPs concerns about how to do long-term migration to 5G and beyond.

Motivation & Objective

• Address the lack of holistic, long-term migration planning for 5G deployment across all network domains (RAN, TN, CN).
• Identify and evaluate E2E migration options that balance technical feasibility, cost, and service KPIs for communication service providers (CSPs).
• Provide a forward-looking vision for 5G evolution (E5G) beyond initial 5G standards, aligning with emerging services like URLLC and mMTC.
• Ensure backward/forward compatibility and interoperability in multi-vendor, heterogeneous network environments during migration.
• Support CSPs in making strategic decisions on when and how to deploy 5G technologies while planning for future 6G evolution.

Proposed method

• Proposes five 3GPP-defined 5G deployment options (Options 1–5) with architectural, cost, and performance trade-offs for E2E migration.
• Analyzes RAN migration via C-RAN evolution using RoE (Radio over Ethernet) to transition from TDM-based to Ethernet-based fronthaul.
• Introduces SDN-enabled transport networks (T-SDN) using hierarchical SDN controllers to manage multi-domain, multi-layer TNs.
• Outlines three deployment models for TN migration: greenfield, mixed, and hybrid, based on device compatibility and upgrade paths.
• Applies a domain-based hierarchical architecture with parent and child SDN controllers to enable incremental, scalable TN evolution.
• Integrates network slicing and E2E management systems to support end-to-end service provisioning and dynamic resource allocation.

Experimental results

Research questions

• RQ1 What are the viable long-term E2E migration paths from 4G to 5G that balance cost, scalability, and service KPIs?
• RQ2 How can CSPs ensure interoperability and forward/backward compatibility during multi-vendor, multi-technology coexistence in 5G networks?
• RQ3 What are the key enablers and timelines for 5G evolution (E5G) beyond 3GPP Releases 15–17, particularly for URLLC and mMTC services?
• RQ4 How can legacy transport networks be evolved to support SDN and network slicing with minimal disruption?
• RQ5 What role do standardization trends (e.g., 3GPP, IEEE, ETSI) play in shaping sustainable 5G and E5G migration strategies?

Key findings

• The paper identifies five 3GPP-defined 5G deployment options (Options 1–5), each with distinct architectural, cost, and performance trade-offs, enabling CSPs to choose based on network maturity and investment capacity.
• Radio over Ethernet (RoE) with CPRI mapping enables a smooth transition from legacy TDM-based 4G C-RAN to Ethernet-based 5G C-RAN, supporting future-proof fronthaul evolution.
• Transport network evolution via T-SDN is feasible through three deployment models—greenfield, mixed, and hybrid—allowing incremental migration with coexistence of legacy and SDN-enabled devices.
• A hierarchical SDN controller architecture (parent and child controllers) enables scalable, domain-based evolution of multi-administrative, multi-layer transport networks.
• E5G (3GPP Releases 18–20) is projected to emerge around 2021–2025, focusing on enhanced URLLC, further eMBB, and reliable mMTC to support next-generation services like telesurgery and autonomous vehicles.
• The paper establishes that 5G evolution is not a one-time event but a continuous process, with 4G and 5G coexistence expected until at least 2022–2023, and 6G research already beginning in parallel.