Description
The Wireline 5G Cable Access Network (W-5GCAN) is a standardized architecture within 3GPP that facilitates the convergence of cable broadband networks, primarily those based on Data Over Cable Service Interface Specification (DOCSIS) standards, with the 5G Core network. Similar to W-5GAN and W-5GBAN, it classifies cable access as a trusted non-3GPP access type. The key network function enabling this integration is a Cable Access Gateway Function, which performs the critical role of protocol adaptation between the DOCSIS cable network domain and the 5G Core domain.
This gateway function interfaces with the Cable Modem Termination System (CMTS) or Converged Cable Access Platform (CCAP) in the cable network. It intercepts control and data traffic from cable modems (CM) and embedded Multimedia Terminal Adapters (eMTAs). The gateway translates cable-specific provisioning, authentication, and management protocols (such as DOCSIS MAC management messages and PacketCable signaling) into 5G-native signaling over the N2 interface to the AMF. For the user plane, it establishes GTP-U tunnels over the N3 interface to a UPF, effectively routing subscriber data traffic directly into the 5G Core's data network, bypassing the traditional cable modem termination system's routing functions.
The technical process involves the cable modem or gateway being recognized as a 5G UE with a subscription in the UDM. During initial provisioning or service flow establishment, the Cable Access Gateway Function facilitates 5G-AKA authentication. Once authenticated, the SMF establishes a PDU Session for the device. The cable network's QoS parameters (e.g., DOCSIS service flows with specific latency and bandwidth guarantees) are mapped to 5G QoS Flows under the control of the PCF. This allows the cable operator to apply the rich policy control, charging, and network slicing capabilities of the 5G Core to its fixed broadband subscribers, creating a seamless service experience across cable and mobile access.
Purpose & Motivation
W-5GCAN was created to address the strategic need for cable network operators (Multi-System Operators or MSOs) to participate in the 5G ecosystem using their extensive Hybrid Fiber-Coaxial (HFC) infrastructure. Historically, cable networks provided broadband internet, voice, and video using entirely separate core networks (PacketCable for voice, DOCSIS for data) from mobile operators. This separation prevented the offering of converged services and resulted in duplicated network functions for authentication, policy, and charging.
The primary problem W-5GCAN solves is the technological silo between the DOCSIS/PacketCable world and the 3GPP mobile world. It provides a clear, standards-based path for cable operators to modernize their networks by adopting a 5G Core, thereby gaining access to advanced 5G capabilities like network slicing for enterprise services, edge computing integration, and unified policy frameworks. This is particularly motivated by cable operators' expansion into mobile services (via MVNO or own radio) and the desire to offer a consistent "wireless-like" experience over their fixed network.
Introduced in Release 16, W-5GCAN leverages the same convergence principles as W-5GAN but tailors them to the specific protocols, QoS models, and operational practices of the cable industry. It addresses limitations of previous convergence attempts by providing native support for cable-specific features like multicast video delivery within a 5G PDU Session context. This enables cable operators to compete effectively with fiber and mobile operators by offering a unified, next-generation service portfolio anchored by their existing coaxial plant.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (53 CRs across 4 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 16, the W-5GCAN function was newly introduced to enable wireline cable access to the 5G Core, defining key elements like the Global Cable Identifier (GCI) for subscriber line identification and the HFC Node ID for user location information. This release specified the architecture and protocols for integrating a 5G-CRG or FN-CRG over a hybrid fiber-coaxial network into the 5GS, including the necessary QoS model extensions and policy control triggers for this convergence.
- SUPI and SUCI for wireline access TS 23.501CR0744
- Mobility restrictions for wireline access TS 23.501CR0745
- Architecture and reference points for Wireline AN TS 23.501CR0863
- Protocol stack for W-5GAN support TS 23.501CR0961
- Extension of the QoS model for wireline access TS 23.501CR0981
- Removal of roaming support from Rel-16 for W-5GAN TS 23.501CR1239
+ 32 more changes
In Release 17, the W-5GCAN function introduced specific user location reporting using a Global Cable Identifier (GCI) and an HFC Node ID, and defined the GCI as a variable-length opaque identifier for the cable line. The release also addressed policy control refinements by correcting supported Policy Control Request triggers and clarified operational constraints, such as not supporting User Location Change reporting for policy control in this access type. Furthermore, it specified details like the MTU value for the wireline cable access.
In Release 18, the W-5GCAN function was extended to support Standalone Non-Public Network (SNPN) access via wireline, enabling cable-connected devices to connect to private 5G networks. This included defining the necessary user location information, specifically the Global Cable Identifier (GCI) and HFC Node ID, for devices accessing the 5G Core via this cable infrastructure. The release also addressed UE policy restrictions specific to wireline access within this convergence architecture.
- Support of wireline access as access to SNPN TS 23.316CR2076
- Support for SNPN via wireline access TS 23.316CR2078
- Support of wireline access as access to NPI-NPN and to SNPN TS 23.316CR2095
- Support of wireline access as access to SNPN TS 23.501CR4124
- Support of SNPN services via wireline access network TS 29.512CR1201
- Non-support of URSP Enhancement for wireless and wireline convergence case TS 29.512CR1235
+ 1 more changes
In Release 19, the W-5GCAN function introduced support for the L4S (Low Latency, Low Loss Scalable Throughput) protocol within the wireline access to manage quality of service. It also enhanced PDU Session handling procedures specific to the cable access network. Furthermore, updates were made to the capability reporting mechanism, clarifying scenarios where the PCRT (PDU Connectivity Request Type) is not supported for the wireline access type.
Explore further
Broader topics and technologies where W-5GCAN plays a role.
Defining Specifications
3GPP specifications that define or reference W-5GCAN, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.003 vj50 | Numbering, addressing and identification in 3GPP | Rel-19 |
| TS 23.316 vj30 | Wireline and Wireless Convergence Access Support | Rel-19 |
| TS 23.501 vk00 | 5G System Architecture Stage 2 | Rel-20 |
| TS 23.716 vg00 | Wireline and Trusted Non-3GPP Access to 5G Core | Rel-16 |
| TS 29.507 vj40 | 5G Access & Mobility Policy Control Service | Rel-19 |
| TS 29.512 vj40 | 5G Session Management Policy Control Service | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |