Description
Non-IP Data Delivery (NIDD) is a core network capability standardized by 3GPP to efficiently support Machine-Type Communication (MTC) and Internet of Things (IoT) devices. It allows for the transmission of small, application-layer data units that are not encapsulated within an IP packet. This is achieved by transporting the data payload directly over the control plane signaling protocols, specifically the Non-Access Stratum (NAS) protocol between the User Equipment (UE) and the Mobility Management Entity (MME) in 4G, or the Access and Mobility Management Function (AMF) in 5G. The data bypasses the traditional user plane bearers (PDN connections or PDU sessions), which are designed for continuous, high-volume IP traffic.
The architectural implementation involves key network functions. In the EPS (4G) architecture, the Serving Gateway (SGW) and Packet Data Network Gateway (PGW) are not used for NIDD traffic. Instead, the MME interacts directly with a Service Capability Exposure Function (SCEF) via the T6a interface. The SCEF acts as an API gateway, securely exposing the NIDD service to external Application Servers (AS). It provides non-IP data delivery, device triggering, and monitoring capabilities. In the 5G System (5GS), the analogous function is the Network Exposure Function (NEF), which interacts with the AMF for control plane data transport.
The procedure for NIDD involves the UE indicating its capability for control plane CIoT EPS/5GS optimizations during attach or registration. When the device or the network has data to send, it is encapsulated within a NAS transport message. For Mobile Originated (MO) data, the UE includes the application data in a NAS message sent to the MME/AMF. The MME/AMF then forwards this data to the SCEF/NEF, which delivers it to the designated AS. For Mobile Terminated (MT) data, the process is reversed: the AS sends data to the SCEF/NEF, which triggers a downlink NAS message to the device via the MME/AMF.
NIDD plays a critical role in enabling massive IoT deployments by significantly reducing signaling and power consumption. Since it uses the always-on signaling connection maintained for mobility management, it eliminates the need for the device to activate a data radio bearer and perform a Service Request procedure for each small data transmission. This is ideal for devices sending infrequent status updates, meter readings, or sensor data, leading to extended battery life (often up to 10 years) and reduced core network processing load.
Purpose & Motivation
NIDD was created to address the fundamental inefficiency of using traditional IP-based mobile data connections for the unique traffic patterns of IoT devices. Early IoT/MTC deployments used standard mobile data, which required establishing a full Packet Data Protocol (PDP) context or PDN connection—a process involving significant signaling exchange and radio resource allocation—even to send a few bytes of data. This was highly wasteful of network resources and device battery power, making large-scale deployments economically and technically challenging.
The primary motivation was to optimize the network for 'sporadic small data transmission,' a hallmark of many MTC applications like smart meters, asset trackers, and environmental sensors. 3GPP recognized that the overhead of IP headers (often 40 bytes for IPv4 or 60+ bytes for IPv6) could be larger than the actual application data payload. By allowing data to be sent without IP encapsulation over the existing control plane signaling path, NIDD drastically reduces protocol overhead and signaling latency.
Historically, NIDD was a key component of the Cellular Internet of Things (CIoT) optimizations introduced in 3GPP Release 13. It solved the limitations of previous approaches by reusing the secure, authenticated NAS signaling connection, thereby providing a lightweight, always-available data path. This enabled new business models and services requiring ultra-low power consumption and high connection density, which were not feasible with conventional mobile broadband architectures.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (114 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-13, normative work from Rel-15.
In Release 15, the NIDD (Non-IP Data Delivery) function was enhanced with new procedures for mobile originated and mobile terminated NIDD, including support for group MT NIDD. The updates formalized SCEF behavior for NIDD configuration, authorization, and delivery procedures, and introduced T8 interface enhancements for direct AS communication and charging management. Furthermore, the release added capabilities for background data transfer policy activation and routing of non-IP traffic between the UE and SCEF.
- Group Message Delivery Procedure changes due to NAPS TS 23.682CR0260
- Background Data Transfer Policy Activation via the SCEF TS 23.682CR0263
- Northbound APIs for SCEF - SCS/AS Interworking - Clause 1-3 enhancements TS 23.682CR0271
- Northbound APIs for SCEF - SCS/AS Interworking - Clause 4 enhancements TS 23.682CR0272
- Enabling the Routing of non-IP traffic between the UE and SCEF TS 23.682CR0277
- SCEF Behaviour in the NIDD Configuration and NIDD Authorisation Update Procedures TS 23.682CR0278
+ 39 more changes
In Release 16, the NIDD function was enhanced with new capabilities including a Downlink Data Delivery Status Event for delivery acknowledgements, a Granted Validity Time for NIDD authorisation, and support for an External Group Identifier. It also introduced specific configurations for these status events and corrections for procedures like Maximum Latency for Mobile Terminating NIDD.
- Notification of Downlink data delivery status and availability after DDN failure notification for multiple Afs TS 29.122CR0156
- Update to NIDD APIs for RDS Dynamic Port Management TS 29.122CR0158
- RDS port mismatch in NIDD TS 29.122CR0205
- Granted Validity Time for NIDD authorisation TS 29.503CR0229
- Downlink Data Delivery Status Event TS 29.503CR0269
- NIDD Authorization Update Notify TS 29.503CR0283
+ 19 more changes
In Release 17, the Non-IP Data Delivery (NIDD) function was enhanced with new authorization mechanisms based on the MTC Provider and S-NSSAI, and its API was significantly refined. The updates included support for the PATCH method for updating resources, improved error handling, and the addition of detailed OpenAPI specification fields like summary and operationId. Furthermore, the release introduced support for redirection for the NIDD API and for legacy 4G SCEF northbound APIs.
- Updates notification destination via PATCH operation in NIDD API TS 29.122CR0444
- Add the support for PATCH method for the update of a NIDD DL Data transfer resource TS 29.122CR0547
- Evolution of UPU delivery mechanism TS 29.503CR0684
- LI for NEF Services (NIDD included) TS 33.127CR0127
- LI for SCEF services TS 33.127CR0128
- Application Identifier for SCEF API ChargebleParty and AS Session with QoS TS 23.682CR0475
+ 17 more changes
In Release 18, the NIDD function within the MSGin5G service introduced support for broadcast message delivery to handle massive communications efficiently, and it enhanced message delivery procedures based on Messaging Topics, including for roaming scenarios. The release also added new message delivery flows, including between different MSGin5G Servers, and improved support for constrained UEs. Furthermore, it expanded capabilities for group messaging and message aggregation based on Messaging Topics.
- Broadcast Message delivery procedure TS 23.554CR0031
- Message delivery based on Messaging Topic for different PLMNs TS 23.554CR0044
- Add message delivery between different MSGin5G Servers TS 24.538CR0032
- ECS Address Configuration Information delivery in roaming TS 29.503CR1039
- Message Aggregation used in Group messaging and Message delivery based on Messaging Topic TS 23.554CR0073
- New Message Delivery Flow TS 23.554CR0138
+ 6 more changes
In Release 19, the NIDD function was enhanced with the new MSGin5G service, which provides point-to-point, application-to-point, group, and broadcast message delivery for IoT communications. Key new capabilities included support for deferred message delivery when a UE is unavailable and the provisioning of parameters like the Messaging Indication via the SCEF. The release also introduced technical clarifications and corrections, such as adding optional serving node information to delivery status reports and defining validity times for NIDD authorization data.
- MSGin5G service in Data delivery management service TS 23.554CR0207
- MSGin5G deferred delivery TS 24.538CR0136
- MPS for Messaging Indication parameter provisioning via SCEF TS 29.122CR0880
- Adding Serving node information as optional IE to Report the SM-Delivery Status TS 29.503CR1474
- Delivery mechanism for the recipient is not registered TS 23.554CR0169
- Clarify the S&F event is sent from SCEF to SCS/AS TS 23.682CR0498
+ 3 more changes
Explore further
Broader topics and technologies where NIDD plays a role.
Defining Specifications
3GPP specifications that define or reference NIDD, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 22.262 vj00 | MSGin5G Service Requirements | Rel-19 |
| TS 23.554 vj70 | MSGin5G Service Application Architecture | Rel-19 |
| TS 23.682 vj30 | 3GPP TS 23682: MTC Architecture Enhancements | Rel-19 |
| TS 23.700 vk00 | XR Services Application Enablement Layer | Rel-20 |
| TS 24.538 vj30 | MSGin5G Service Protocol Specification | Rel-19 |
| TR 28.816 vh00 | Charging for 5G Cellular IoT | Rel-17 |
| TS 29.122 vj40 | T8 Reference Point for Northbound APIs | Rel-19 |
| TS 29.336 vj10 | HSS Diameter Interfaces for PDN Interworking | Rel-19 |
| TS 29.503 vj50 | UDM Service Based Interface Stage 3 | Rel-19 |
| TS 29.541 vj30 | NEF Service-Based Interfaces for NIDD & SMS | Rel-19 |
| TS 29.542 vj30 | SMF NIDD Service Based Interface Stage 3 | Rel-19 |
| TS 32.253 vj00 | Charging for Control Plane Data Transfer | Rel-19 |
| TS 32.298 vj30 | Charging Data Record (CDR) Parameter Specification | Rel-19 |
| TS 32.299 vj00 | Diameter Charging Applications for 3GPP | Rel-19 |
| TS 33.108 vj00 | LI Handover Interface Specification | Rel-19 |
| TS 33.127 vj50 | Lawful Interception Architecture and Functions | Rel-19 |