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
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (41 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 newly introduced, defining an HSDN cell as one with higher priority for cell reselection specifically for HSDN-capable UEs in a High-mobility state. The release specified that such a UE in the High-mobility state must always consider HSDN cells as the highest priority, overriding other network-configured priorities, and clarified speed-dependent mobility procedures alongside corrections for handling dedicated cell reselection priorities.
- TS 36.304 running CR for HSDN TS 36.304CR0410
- Running 36.331 CR for HSDN TS 36.331CR3343
- Corrections to 36.304 speed dependent mobility and inter-RAT cells with cell reservations, access restrictions, or unsuitable for normal camping TS 36.304CR0748
- RRC corrections for URLLC TS 36.331CR3751
- CQI and MCS for URLLC TS 38.300CR0154
- Clarification on dedicated serving cell configuration in Re-establishment TS 38.331CR0823
+ 1 more changes
In Release 16, the new HSDN (High Speed Dedicated Network) function introduced UE capabilities and signalling specifically for high-speed train scenarios. The key enhancement was a new cell reselection rule where an HSDN-capable UE in a High-mobility state must always consider HSDN cells to be the highest priority, overriding all other network-configured priorities. Conversely, when not in a High-mobility state, the UE treats HSDN cells as the lowest priority.
- Introduction of UE capabilities for further performance enhancement for LTE in high speed scenario in Rel-16 TS 36.306CR1712
- Introduction of signalling for high-speed train scenarios TS 36.306CR1767
- Introduction of RRC parameters and UE capabilities for enhanced high speed scenario TS 36.331CR4095
- Introduction of signalling for high-speed train scenarios TS 36.331CR4326
- Introduction of signalling for high-speed train scenarios TS 38.331CR1464
- Correction on the configuration of subframe #0 and #5 for MCH in MBMS dedicated cell TS 36.331CR4259
+ 1 more changes
In Release 17, the key enhancement for HSDN 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 shall always consider HSDN cells to be the highest priority for reselection, overriding any other network-configured priorities. Conversely, when the UE is not in a High-mobility state, it shall treat those same HSDN cells as the lowest priority.
- Introduction of mobility-state-based cell reselection for NR HSDN [NR_HSDN] TS 36.331CR4730
- Introduction of Rel-17 IIoT/URLLC to TS 38.300 TS 38.300CR0416
- 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
- Introduction of enhanced IIoT&URLLC support for NR TS 38.331CR2887
+ 3 more changes
In Release 18, the HSDN (High Speed Dedicated Network) function was enhanced to improve cell reselection for capable UEs by introducing specific behavior based on the UE's mobility state. When an HSDN-capable UE is in a High-mobility state, it must always consider HSDN cells as the highest priority, overriding any other network-configured priorities. Conversely, when not in a High-mobility state, the UE must treat HSDN cells as the lowest priority.
- Introduction of NR support for dedicated spectrum less than 5MHz for FR1 TS 36.331CR4983
- Introduction of Timing Resiliency and URLLC enhancements TS 38.300CR0730
- Introduction of NR support for dedicated spectrum less than 5MHz for FR1 TS 38.300CR0766
- Introduction of URLLC and Timing Resiliency TS 38.331CR4258
- Introduction of NR support for dedicated spectrum less than 5MHz for FR1 TS 38.331CR4525
- Correction on UAI for URLLC TS 38.300CR0793
+ 5 more changes
In Release 19, the HSDN function was enhanced with the introduction of Automatic Neighbour Relation (ANR) reporting specifically for HSDN cells, improving network management. Furthermore, the release defined that an HSDN-capable UE must consider HSDN cells as the highest priority when in a High-mobility state, a condition now detectable in RRC_CONNECTED with the addition of Mobility State reporting.
- Introduction of ANR reporting of HSDN cells [ANR_HSDN] TS 36.306CR1911
- Introduction of ANR reporting of HSDN cells [ANR_HSDN] TS 36.331CR5110
- Introduction of ANR reporting of HSDN cells [ANR_HSDN] TS 38.306CR1264
- Adding Mobility State in RRC_CONNECTED [SpeedStatePars] TS 38.306CR1395
- Introduction of ANR reporting of HSDN cells [ANR_HSDN] TS 38.331CR5318
- Adding Mobility State in RRC_CONNECTED [SpeedStatePars] TS 38.331CR5615
+ 1 more changes
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 |