The nRF9151 SiP contains a Low-Power Wide-Area (LPWA) network processor with dedicated flash/RAM, which controls the radio and baseband hardware components. DECT NR+ (NR+) capabilities are provided by installing Nordic Semiconductor firmware, that implements the physical layer (PHY) level operation of the NR+ radio protocol stack according to ETSI specifications (TS 103 636-2 and TS 103 636-3). Current implementation supports standard v1.5.1.
NR+ runs an alternative modem firmware that is separately available from Nordic Semiconductor. When using NR+, the LTE and GPS functionality cannot be used.
NR+ is a non-cellular radio standard included as part of the 5G standards by the International Telecommunication Union (ITU). It is designed for massive Machine Type Communication (mMTC) and for Ultra-Reliable Low Latency Communication (URLLC).
NR+ operates on the global and license-exempt 1.9 GHz band, which significantly cuts deployment costs by eliminating the need for frequency planning or heavy certification. The NR+ device developer can design optimal radio behavior since there is no need for third-party cellular infrastructure. Additionally, the range and dense topology properties of NR+ make it highly scalable. A square kilometer can be covered by as little as 100 devices or scaled up to over 1 million devices while maintaining the same reliable, low-latency communication.
The physical radio layer in NR+ reuses known techniques from cellular radios, reaching the same level of reliability that is proven by billions of devices already in the field.
The following are key features of NR+:
- License-exempt global band
- Built-in coexistence of multiple networks in the same location
- Flexible, low-latency system and network architectures
- High reliability, using hybrid ARQ
- Possibility of hiding the network, using AES-128 encryption and integrity protection
- Peak data rate up to 3.4 Mbps, depending on modulation
See ETSI TS 103 636-1 for more information.
Application and LPWA network domains interact through the interprocessor communication (IPC) mechanism. The application processor is the system master and is responsible for starting and stopping the NR+ device. The LPWA network processor enables the clocks and power required for its own operation. The platform handles shared resources, such as clocks, and does not need user participation.
massive Machine Type Communication (mMTC)
mMTC is used for large networks with machine-type devices, connecting tens of billions of nodes that operate for many years using small batteries and transmit small amounts of data.
Typical use cases involve collecting measurements from many sensors, such as smart metering, which requires a low-maintenance and low-cost autonomous network structure.
A key feature of NR+ is its self-healing and self-organizing properties. Each node can function as a router to an access point with a connection to the internet. Nodes can change to a routing role based on the needs of the network. Multiple access points to the internet can be supported in a single network. These properties eliminates single points of failure and resolves high-traffic situations that can occur in dense IoT networks.
Ultra-Reliable Low-Latency Communication (URLLC)
URLLC enables mission-critical wireless use cases where failure is not an option.
Examples include management of self-driving factory vehicles, high-speed robots working alongside human operators in warehouses, and critical infrastructure in buildings, cities, and utilities.
NR+ is designed to reach one-millisecond latency between devices, opening the possibility for low-latency systems to consider wireless operation, even where ranges are over a kilometer. This makes NR+ an open, standardized alternative to existing proprietary technology.
DECT NR+ on the nRF9151
Nordic Semiconductor provides NR+ firmware that implements the physical layer (PHY) level operation of the NR+ radio protocol stack according to ETSI specifications (TS 103 636-2 and TS 103 636-3).
The antenna interface and recommendations are the same as for the LTE modem. NR+ does not require a SIM or eSIM.
Key RF Parameters
NR+ RF performance parameters are shown in the following table.
| Description | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Bands supported | 1, 2, 4, 9, 22 | |||
| Transmission Bandwidth | 1.728 | MHz | ||
| Occupied Bandwidth | 1.539 | MHz | ||
| Antenna impedance, single-ended | 50 | Ω | ||
| RX: Sensitivity |
-105 dBm, PLCF Type 1 (beacon reception, MCS 0) -103 dBm, PLCF Type 2 (unicast reception, MCS 1) |
dBm | ||
| TX: Maximum output power |
19 dBm on band 4 21 dBm on bands 1, 2, 9, 22 |
dBm | ||
| TX: Minimum output power | -40 | dBm |
DECT NR+ coexistence interface
NR+ uses a dedicated two-pin coexistence interface to avoid RF interference to a companion radio device such as an external positioning device or a Bluetooth® Low Energy device.
The user can configure COEX0 and COEX2 pin functions through the NR+ AT commands.