Description
High Speed Dedicated Network (HSDN) is a deployment concept within the 5G New Radio (NR) framework, referring to dedicated networks built to deliver high-speed, reliable, and low-latency connectivity for specific enterprise or vertical industry applications. The architecture involves a dedicated radio access network (RAN) and often a dedicated core network (e.g., 5GC), operating either as a fully standalone non-public network (NPN) or as a virtual slice within a public network. Key components include gNBs (5G base stations) deployed on-premises or in a dedicated area, User Equipment (UE) tailored for the use case, and a core network that can be locally hosted. The RAN operates in licensed, unlicensed, or shared spectrum (like CBRS), with configurations optimized for coverage, capacity, and interference isolation.
HSDN works by allocating dedicated network resources exclusively for the use of a specific organization or service. The gNBs are configured with parameters prioritizing high throughput (e.g., wide bandwidth carriers, advanced MIMO) and ultra-reliable low-latency communication (URLLC) features like shortened transmission time intervals (TTI) and redundant transmission paths. UEs access the network using standard 5G NR procedures, but access control is restricted to authorized users, often using closed access group (CAG) or network identifier (NID) mechanisms defined for non-public networks. The core network, if dedicated, hosts application functions (AF) and user plane functions (UPF) locally to minimize latency and keep sensitive data on-site.
Its role is to provide a tailored connectivity solution that public networks cannot guarantee due to shared resource contention. It is documented in RAN specifications (e.g., TS 38.300, TS 36.304) covering UE requirements and procedures in such environments. HSDN supports critical communications for factories (Industry 4.0), smart grids, ports, and campuses, where performance, security, and control are paramount. It coexists with public network deployments but is logically or physically separated to meet stringent service level agreements (SLAs).
Purpose & Motivation
HSDN was introduced to meet the demanding connectivity requirements of vertical industries and enterprises that cannot be satisfied by conventional public mobile broadband networks. These industries, such as manufacturing, energy, and logistics, needed networks with guaranteed high speed, ultra-low latency, high reliability, and strong data privacy. Public networks, designed for broad consumer coverage and shared capacity, often lack the deterministic performance and control required for industrial automation, remote control, and sensitive operations.
The creation of HSDN in Release 15 was motivated by the 5G design principles of supporting enhanced Mobile Broadband (eMBB), URLLC, and massive Machine-Type Communications (mMTC). It addresses the limitations of previous enterprise solutions like Wi-Fi (limited mobility, interference) or early 4G private networks (limited performance customization). HSDN leverages 5G NR's technical advancements—such as flexible numerology, network slicing, and edge computing—to create dedicated networks that are as capable and manageable as traditional wired industrial networks but with wireless flexibility. It enables digital transformation in sectors where connectivity is a critical operational tool.
Classification
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (13 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the HSDN (High Speed Dedicated Network) function was introduced, defining HSDN cells and the behavior of HSDN-capable UEs. The specifications were updated to detail that an HSDN cell has the highest priority for cell reselection when the UE is in a High-mobility state, and the lowest priority otherwise. These changes were documented in running Change Requests for the UE procedures specifications TS 36.304 and TS 36.331.
In Release 16, the new functionality for HSDN (High Speed Dedicated Network) included the addition of a missing HSDN UE capability for LTE. This capability allows a UE to identify HSDN cells, which are given the highest priority for cell reselection when the capable UE is in a High-mobility state, and the lowest priority otherwise. The release also defined procedures for state transitions into this High-mobility state based on specific detection criteria.
- Add the missing HSDN UE capability for LTE TS 36.306CR1829
In Release 17, the key enhancement for the HSDN function was the introduction of mobility-state-based cell reselection for NR HSDN. This new procedure mandates that an HSDN-capable UE in a High-mobility state must always consider HSDN cells to be the highest priority for reselection, overriding other network-configured priorities. The release also included clarifications on priority handling for HSDN cells relative to other services like MBS and V2X.
- Introduction of mobility-state-based cell reselection for NR HSDN [NR_HSDN] TS 36.331CR4730
- Introduction of mobility-state-based cell reselection for NR HSDN [NR_HSDN] TS 38.304CR0223
- Introduction of mobility-state-based cell reselection for NR HSDN [NR_HSDN] TS 38.306CR0650
- Introduction of mobility-state-based cell reselection for NR HSDN [NR_HSDN] TS 38.331CR2846
- Clarification on cell reselection priority handling for HSDN, MBS, V2X/NR sidelink, Slicing and deprioritization request TS 38.304CR0310
In Release 18, the specification introduced a correction for cell type specific cell reselection prioritisation for HSDN (High Speed Dedicated Network). This refinement explicitly defined that an HSDN-capable UE in a High-mobility state must always consider HSDN cells as the highest priority for reselection, overriding any other network-configured priorities. Conversely, when not in a High-mobility state, the UE must treat those same HSDN cells as the lowest priority.
- Correction on cell type specific cell reselection prioritisation [NR_HSDN] TS 38.300CR0993
In Release 19, the key enhancement for the High Speed Dedicated Network (HSDN) function was the introduction of Automatic Neighbour Relation (ANR) reporting specifically for HSDN cells. This new capability allows the network to automatically discover and manage neighbouring HSDN cells, which are defined as cells providing higher reselection priority for HSDN-capable UEs in a high-mobility state. The update integrates HSDN into the existing ANR framework, enabling more efficient network optimization for high-speed scenarios.
Explore further
Broader topics and technologies where HSDN plays a role.
Defining Specifications
3GPP specifications that define or reference HSDN, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 36.304 vj00 | UE Idle Mode Procedures in E-UTRA | Rel-19 |
| TS 36.306 vj00 | E-UTRA UE Radio Access Capability Parameters | Rel-19 |
| TS 36.331 vj00 | LTE RRC Protocol Specification | Rel-19 |
| TS 38.300 vj00 | NG-RAN Overall Description | Rel-19 |
| TS 38.304 vj00 | UE RRC_IDLE and RRC_INACTIVE Procedures | Rel-19 |
| TS 38.306 vj00 | NR UE Radio Access Capability Parameters | Rel-19 |
| TS 38.331 vj00 | NR Radio Resource Control (RRC) Protocol Specification | Rel-19 |
