Radio Access Network (RAN)
This page summarizes most relevant open-source solutions for RAN applications.
Open Air Interface (OAI)
OAI provides software-based implementations of LTE base stations (eNBs), UEs and EPC compliant with LTE Release 8.6 (with an additional subset of features from LTE Release 10). OAI source code is written in C to guarantee real-time performance, and is distributed under the OAI Public License, a modified version of the Apache License v2.0 that allows patent-owning individuals and companies to contribute to the OAI source code while keeping their patent rights. Both the eNB and UE implementations are compatible with Intel x86 architectures running the Ubuntu Linux operating system. (An experimental version for the CentOS 7 is under development.) Several kernel- and BIOS-level modifications are required for these implementations to achieve real-time performance, including installing a low-latency kernel, and disabling power management and CPU frequency scaling functionalities.
srsLTE provides software implementations of LTE eNB, UE, and EPC compliant with LTE Release 10 (with some features from higher versions, e.g., NR Release 15). The software suite is written in the C and C++ programming languages and it is distributed under the GNU AGPLv3 license. srsLTE is compatible with the Ubuntu and Fedora Linux distributions. It does not require any kernel- or BIOS-level modifications to achieve real-time performance though disabling CPU frequency scaling is recommended.
Radisys O-RAN gNB DU
Radisys is a 4G/5G vendor that contributes to a number of open source software consortia, including O-RAN and several Open Networking Foundation (ONF) initiatives.As part of O-RAN, Radisys provides an open source implementation of the 3GPP NR stack for the gNB DU. To date, does not represent a complete solution that can be deployed to run real-world experiments (as with OAI and srsLTE), as it lacks integration with open source CU and RU implementations. However, this represents a key first step toward the availability of an open source 5G gNB based on the CU/DU split principle. he currently available open source code provides a complete implementation of the MAC and RLC layers. The Radisys release also provides a layer that manages the operations of the DU and interfaces it with the CU, the RU and external controllers, when available. The codebase is aligned with Release 15 of the 3GPP NR specifications. The NR MAC uses the Functional Application Platform Interface (FAPI) to interact with a scheduler, adapted from an LTE implementation. The RLC layer supports TM, UM, AM modes.