Robustel R2120-5G
Industrial Dual-SIM 5G NR Cellular PoE-PSE Router with RS-485
The Robustel R2120 5G is an industrial cellular PoE router designed for field deployments where connected cameras, controllers, sensors, access devices, and legacy equipment need reliable high-capacity backhaul from a single compact router.
Built around the same practical PoE-PSE architecture as the R2120 platform, the 5G variant adds 5G NR SA/NSA connectivity with broad global band support, while retaining five Gigabit Ethernet ports, four 802.3af/at PoE-PSE ports, dual SIM, Wi-Fi, RS-485, digital I/O, and remote management through RCMS.
For systems integrators and operators, this makes the R2120 5G especially useful in distributed sites where several IP devices must be powered, connected, monitored, and remotely maintained without adding separate PoE switches, cellular gateways, or site visits for basic recovery tasks.
DUAL-SIM CELLULAR
5G, 4G/LTE, 3G & 2G with Dual-SIM Card support for failover
PoE-PSE
4× IEEE 802.3af/at PoE‑PSE Ethernet ports
INTERFACES
1x WAN, 4x LAN, 1x RS-485,
2x DI/DO
OPERATING SYSTEM
RobustOS – Lightweight Linux kernel with full SDK
RCMS ON-BOARD
RCMS Cloud device management enabled
Example R2120-5G Use Cases
High-Definition Multi-Camera

A 4K IP camera running H.265 compression generates 8–20 Mbps of upstream traffic depending on scene activity. Four of them, all drawing power from the R2120 5G’s PoE-PSE ports and pushing video simultaneously, puts aggregate upstream demand in the 32–80 Mbps range. That load is manageable on a well-provisioned LTE connection — until it isn’t: cell congestion, edge-of-coverage attenuation, and peak-hour contention all erode LTE uplink headroom in ways that are difficult to predict at the planning stage. The R2120 5G’s 5G NR uplink provides the capacity margin to run that camera density reliably without dialling down resolution or frame rate to compensate for backhaul constraints. Relevant at construction site perimeters, transport hub surveillance rings, warehouse security arrays, and any deployment where PoE camera count and image quality are both non-negotiable.
Smart Traffic Infrastructure

A fully instrumented intersection — ANPR cameras, PTZ overviews, inductive loop detectors, variable message signs — generates both high-bandwidth video and latency-sensitive control traffic at the same time. The R2120 5G carries the video upstream over 5G NR while the RS-485 port handles direct serial communication with legacy traffic controllers that pre-date IP integration. The 2× DI and 2× DO interfaces support hardwired trigger logic — incident detection outputs, signal state inputs — reducing the dependency on application-layer polling for time-critical events. For city authorities and traffic management integrators deploying at scale, the global band set means the same device specification travels across different carrier environments without a hardware change.
5G for Temporary Sites

Construction projects, major public events, and critical infrastructure protection share a common constraint: the security system needs to be operational quickly on a site with no fixed connectivity infrastructure. The R2120 5G consolidates power and backhaul into a single device — one 48V DC feed, four PoE-powered cameras, 5G uplink to the monitoring platform. Where 5G coverage exists, this eliminates cable trenching and reduces on-site installation to hours rather than days. RCMS allows the deployed fleet to be provisioned, monitored, and updated centrally, so that as sites are stood up or decommissioned, the management overhead doesn’t scale linearly with device count.
Looking for more use cases?
With millions of Robustel devices deployed across more than 100 countries, it’s impossible to capture every use case above. Explore the links below to discover some of the exciting and innovative ways our technology is making an impact worldwide.
This Device is RCMS Ready
RCMS is a cloud-based IoT device management platform that gives you real-time visibility across your entire Robustel fleet. So you can troubleshoot, update, and optimize performance from anywhere at anytime, without sending engineers to site.
Product Mounting Options
Desktop Mount

DIN Rail Mount

Wall Mount

System Architecture
|
Operating System |
RobustOS |
|
CPU |
MT7621, 880MHz |
|
RAM |
512MB |
|
Flash |
32MB |
Cellular
|
Supported Technologies |
5G, 4G/LTE, 3G, 2G |
|
Antennas |
4 (MAIN + DIV) |
|
Connector |
SMA-K |
|
SIM |
2 x Mini SIM (2FF) |
Ethernet
|
Ethernet Ports |
5 x 10/100/1000 Mbps – 1 x WAN + 4 LAN or 5 x LAN (Default) |
|
Magnet Isolation Protection |
1 KV |
PoE Out
|
PoE Ports |
ETH1 – ETH4 |
|
PoE Standards |
802.3at, 802.3af |
|
PoE Max Power per Port (PSE) |
Up to 30W |
|
Total PoE Power Budget (PSE) |
Dependent on PSU Capacity |
Serial Port
|
Serial Ports |
1 x RS-485 |
|
Connector |
1 x 3-pin 3.5mm female socket |
|
ESD Protection |
±8 KV air discharge, ±4 KV contact discharge |
|
Baud Rate |
300 bps – 115200 bps |
|
Signal Definition |
RS-485: A, B, GND |
Digital Input/Output
|
DI/DO Ports |
2 x DI + 2 x DO (wet contact) |
|
Connector |
2, each with 4-pin 3.5mm female sockets |
|
Isolation |
3.75 KV DC (opto-isolator) |
|
Absolute Maximum VDC |
+30V DC (DI), +30V DC (DO) |
|
Absolute Maximum ADC |
100 mA (DO) |
|
Signal Definition |
DI1+, DI1-, DI2+, DI2-, DO1+, DO1-, DO2+, DO2- |
Wi-Fi
|
Wi-Fi Antennas |
2 (Wi-Fi 0 + Wi-Fi 1) |
|
Connector |
RP-SMA-K |
|
Standards |
802.11 a/b/g/n/ac, 2 x 2 MIMO, supporting AP and Client modes |
|
Frequency Bands |
2.412 ~ 2.472 GHz (2.4 GHz ISM band) |
|
Security |
WPA, WPA2, WEP, WPA3 |
|
Encryption |
AES, TKIP, WEP64 |
Other Interfaces
|
Reset Button |
1 x RST |
|
LED Indicators |
1 x RUN, 1 x RSSI, 1 x MDM, 1 x USR |
|
Watchdog |
Built-in |
Power Supply & Consumption
|
PSU Connector |
2-pin 3.5mm female socket with lock |
|
Input Voltage |
44 – 57 V DC |
|
Power Consumption |
Idle: 4.5 W@48 V, excluding the PoE consumption |
|
Recommended Power Supply |
48 V DC, 1.25 A (60 W) |
Note:
1. Total power = System 12 W + ∑PoE loads
2. For 100 m cable runs with 30 W loads per port, consider 54 V DC PSU
Physical Characteristics
|
Ingress Protection |
IP30 |
|
Housing & Weight |
Aluminium, 539g |
|
Dimensions |
49x105x143mm |
|
Installation Options |
Desktop, Wall Mount and 35mm DIN Rail |
|
Operating Temperature |
-20 – +70°C |
|
Storage Temperature |
-40 – +85°C |
|
Relative Humidity |
5 – 95% RH (non-condensing) |
Software Features
|
Network Protocols |
PPP, PPPoE, TCP, UDP, DHCP, ICMP, NAT, HTTP, HTTPs, DNS, NTP, SMTP, Telnet, ARP, VLAN, SSH2, DDNS, etc. |
|
VPN Tunnels |
IPsec, OpenVPN, GRE, WireGuard |
|
Firewalls |
DMZ, anti-DDoS, Filtering (IP/Domain name/MAC address), Port Mapping, Access Control |
|
Remote Management |
RCMS, Web, CLI, SMS |
|
Serial Port Protocols |
Transparent, TCP Client/Server, UDP, Modbus RTU to TCP |
|
SIM Management |
Smart Roaming |
|
Optional Apps |
L2TP, PPTP, DMVPN, VRRP, QoS, SNMP, Language, RCMS, Dynamic Route, Captive Portal, Modbus Master, TR069, Edge2Cloud, etc. |
Software Development Kit (SDK)
|
Supported Programming Languages |
C, C++ |
|
Flash available for SDK |
5MB |
|
RAM available for SDK |
256MB |
Regulatory and Type Approvals
|
Environmental |
RoHS 2.0, WEEE |
|
Testing |
IEC 60068-2-6 (Sinusoidal Vibration) |
|
EMI |
EN 55032 Conducted Emission Class B |
|
EMS |
EN 61000-3-2 (Harmonic Current) |
Available Models
|
Model |
Supported Frequency Bands |
Certifications |
Order Code |
Package Contents |
|
R2120-A5AAA-5G-A25GL |
5G NR SA/NSA: n1/2/3/5/7/8/12/13/ 14/18/20/25/26/28/29/30/38/40/ 41/48/66/70/71/75/76/77/78/79 14/17/18/19/20/25/26/28/29/30/ 32/66/71 4G/LTE TDD: B34/38/39/40/41/42/43/48 LAA: B46 (only supports 2 x 2 MIMO) |
CE, UKCA |
|
1x Router (B Code: B015000003) 1x DIN Rail Mounting Kit |
|
R2120-A5AAA-5G-A25GL |
5G NR SA/NSA: n1/2/3/5/7/8/12/13/ 14/18/20/25/26/28/29/30/38/40/ 41/48/66/70/71/75/76/77/78/79 14/17/18/19/20/25/26/28/29/30/ 32/66/71 4G/LTE TDD: B34/38/39/40/41/42/43/48 LAA: B46 (only supports 2 x 2 MIMO) |
CE, UKCA |
|
1x Router (B Code: B015000003) 1x DIN Rail Mounting Kit 4x Cellular Antenna 2x Wi-Fi Antenna 1x Power Adapter |
NOTE:
1. For more information about regional & carrier specific variants please contact us
R2120-5G Downloads
Please note that all product downloads are now located on the Robustel Knowledge Base (https://support.robustel.com) the buttons below will take you to the relevant sections for each product.
Product Documentation
Firmware, Software & Applications
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