The software radio systems Radio Access Network or srsRAN project aims to implement 4G/LTE and 5G stacks. Previously, the project was known as srsLTE.
Main changes compared to the previous version:
- Fixed srsUE errors associated with widths of 5, 10, 15 and 20 MHz.
- Added a new algorithm for frequency calculation.
- Updated cmake.
- Some bug fixes to improve stability and performance.
Main modules of srsRAN 4G:
- srsENB (software radio systems eNodeB) - implementation of Evolved UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network NodeB or E-UTRAN NodeB or simply eNodeB (eNB). Essentially this is a software implementation of a 4G/LTE base station;
- srsUE (software radio systems User Equipment) - implementation of a 4G/LTE modem that can connect to the eNB base station;
- srsEPC is an implementation of the network core, which includes MME (Mobility Management Entity), HSS (Home Subscriber Server), SGW (Serving Gateway) and PGW (PDN (Packet Data Network) Gateway).
- implementation of the stack of both the base station and the software modem;
- it is possible to work with both software and hardware SIM cards (via PC/SC) for srsUE;
- support for bandwidths of 1.4, 3, 5, 10, 15 and 20 MHz;
- AES support;
- optimization for SSE4.1/AVX2;
- LTE Release 10 support;
- Intra-ENB and Inter-ENB support for eNodeB.
It is worth noting that srsRAN is developing and O-RAN 5G support.
Main restrictions
- No VoLTE support. (VoLTE can be implemented using a third party IMS, such as Kamailio, which is located at kamailio.org using the article https://open5gs.org/open5gs/docs/tutorial/02-VoLTE-setup and this is how VoLTE works https://www.youtube.com/watch?v=gBX-ZX_d1uY)
- For 5G, only support for gNodeB (next generation NodeB) is implemented for both CU and DU/RU - that is, the base station, but the soft modem is not implemented.
- Only FR1 is supported.
- No 2G or 3G support.
Unlike Osmocom CNI, srsRAN is aimed at creating a 4G and 5G stack for transmitting IP traffic. At the same time, Osmocom CNI is aimed at implementing 2G and 3G, which are focused on SMS, USSD and voice transmissions. That is why Osmocom CNI can transmit voice traffic not only to IP-PBX (IP-PBX) like Asterisk but also, for example, to E1 using icE1usb.
Source: linux.org.ru
