uSDR is a compact M.2 software-defined radio designed for practical RF experimentation, embedded integration, and browser-based SDR workflows. One of the most useful application areas for uSDR is cellular network experimentation.
Using uSDR with srsRAN_4G, developers can build LTE test networks for private cellular research, telecom education, wireless prototyping, and SDR-based system development.
This type of workflow is valuable for teams studying eNodeB behavior, EPC configuration, private SIM provisioning, RF performance, and LTE network behavior in controlled lab environments.
Reference: Running an srsRAN LTE Network with uSDR — Crowd Supply update.
| Interface | Practical LTE Bandwidth | Best For |
|---|---|---|
| USB2 | up to 5 MHz with 12-bit I/Q | Portable LTE labs, classroom demos |
| USB3 | wider configurations | Higher-rate prototyping |
| PCIe | full bandwidth | High-performance LTE / 5G research |
uSDR software updates for LTE workflows
Wavelet Lab's uSDR software development has continued to improve performance and compatibility for cellular use cases.
The uSDR software stack supports SoapySDR-based workflows, allowing srsRAN to interface with uSDR through a standard SDR abstraction layer. This makes it possible to run an LTE eNB and EPC configuration using open-source software and compact hardware.
Support for 12-bit I/Q format helps improve USB2 throughput and enables practical 5 MHz LTE operation over USB2. For wider configurations and higher throughput, PCIe connectivity provides more headroom.
Why srsRAN matters
srsRAN is a widely used open-source cellular software stack for LTE experimentation. It includes components for user equipment, base-station operation, and core network functionality.
With uSDR, the typical workflow focuses on a simple eNB plus EPC setup:
- configure EPC network parameters
- configure SIM card credentials
- set MCC and MNC values
- configure the eNB
- connect uSDR through SoapySDR
- run the LTE test network
- attach a phone or test UE using a compatible SIM
This makes uSDR useful for learning how cellular systems operate from the RF layer through authentication and data connectivity.
LTE bandwidth options
Because USB2 has limited bandwidth, lower LTE bandwidths are the most practical option for USB-connected operation. With optimized 12-bit I/Q streaming, 5 MHz LTE operation becomes practical over USB2.
PCIe connectivity provides more flexibility for wider LTE configurations and higher throughput operation.
This gives users two paths:
- USB2 for compact, accessible LTE experimentation
- PCIe for higher-performance SDR workflows
Private SIM cards and controlled testing
Running a private LTE test network requires compatible SIM cards and proper network configuration. Users typically need preprogrammed test SIMs or programmable SIM cards with known authentication credentials.
This is important because LTE attachment depends on proper matching between the SIM credentials and the EPC user database.
For research and lab environments, this setup allows engineers to study authentication, attachment, data sessions, RF behavior, and throughput in a controlled environment.
Applications
uSDR with srsRAN can support:
- LTE lab networks
- private cellular experimentation
- telecom education
- eNodeB prototyping
- EPC configuration testing
- RF performance testing
- SDR-based LTE research
- compact wireless demos
- embedded cellular development
From native LTE workflows to WebSDR
srsRAN represents a native SDR workflow, while WebSDR represents Wavelet Lab's browser-based direction. See also the cloud-based cellular network in a browser with uSDR update.
Together, they show how uSDR can support both traditional open-source SDR tools and newer web-native RF workflows.
This dual approach gives developers flexibility: use native tools like srsRAN, GNU Radio, and SoapySDR when they need direct control and performance, or use WebSDR when they want browser-based setup, visualization, application building, and remote workflows.