OpenBSC November 2025

openbsc@lists.osmocom.org

17 participants
25 discussions

Front and back sides of an MSC
by Mychaela Falconia 09 Dec '25

09 Dec '25

Hello Osmocom community, I have a question about terminology that is not really specific to Osmocom, but is specific to GSM/3G/etc cellular industry, or whatever is left of it. An MSC in a GSM or 3G or any other circuit-switched cellular network has two sides: one side facing the RAN (A interface in GSM, IuCS in 3G), the other side facing PSTN or ISDN or BICC or SIP-I or whatever the fixed telephone network may be. My question: is there a general industry-wide agreement as to which side should be called the front and which should be called the back? To me it seems intuitive to refer to the A/IuCS side of an MSC as the front and the PSTN/ISDN/BICC/SIP-I side of the same MSC as the back. However, I am just one person, and I have no idea whether or not my view is intuitive to others. And it would even worse if the opposite convention happens to be widely used... Hence I am asking this community, in the hope that someone with more industry experience would know how telco network engineers casually refer to RAN-facing and fixed-network-facing sides of an MSC. For a long time I had the idea of building ThemWi MSC as a modular system (multiple processes talking to each other via sockets) with a stripped-down OsmoMSC derivative as the "central" component, and with a radically different placement of MSC-MGW. However, as I started working on more detailed design, I realized a major flaw in my originally envisioned architecture: my original approach to MSC-MGW would break TFO for AMR, specifically the dialogue between TFO-aware BTS and the TRAU equivalent in the MGW. I am now spinning a new architecture in my head, one which tentatively includes two dissimilar MGWs in the MSC. If my front vs back terminology is valid, then the front MGW (talking to AoIP user plane) would perform speech transcoding but become a transparent pass-through for CSD (basically a software-only, IP-based equivalent of a hardware TCSM colocated at the MSC site), while the back MGW would be a transparent pass-through for speech calls, but turn into a complex IWF for CSD. This tentative architecture exactly matches the placement of speech transcoding and CSD IWF functions in traditional hardware MSCs of TDM-based, before-AoIP world. But I need to know if I should keep these front and back terms, or swap them the other way around. M~

3 3

osmo-trx-ms documentation
by Степан Королев 08 Dec '25

08 Dec '25

Hello. I'm looking for a replacement for grgsm_trx, and I came across osmo- trx-ms in the osmo-trx repository. But I came across a lack of information about this project. You can find out its status and whether it is recommended to use it in principle as a Front-End SDR for osmocom-bb mobile.

4 3

osmo-trx tx/rx Tx / Rx sample offset measure
by nero.moonnn＠gmail.com 28 Nov '25

28 Nov '25

Hello, everyone! How can I correctly measure the TX/RX sampling offset? I need to implement a new sampling frequency (7.68e6) for usrp b200. I added the coefficients for the receiver, and the transmission looks fine, but the reception is not working. I think it's all about the TX/RX sampling offset. What are some ways to measure this offset? Maybe there's something ready-made?

1 0

Struggling with Your Final Research? Let's Talk About PhD Dissertation Help!
by teves20525＠binafex.com 27 Nov '25

27 Nov '25

I’ve been spending weeks trying to find a reliable dissertation writing help service, but the options online feel endless and honestly, overwhelming. Some seem legit, others not so much. I'm at the PhD level, so the stakes are high, and I can’t afford to take risks on poor quality or generic content. Has anyone here actually used a dissertation writing service they’d recommend? I’m especially looking for something that offers strong PhD dissertation help with proper research support. What red flags should I watch for? How do you even verify a service is trustworthy? Any insights or personal experiences would really help me (and others) out! https://www.dissertationproposal.co.uk/dissertation-services/phd-dissertati…

3 4

New MGW for E1 Abis, future ThemWi sw plans
by Mychaela Falconia 24 Nov '25

24 Nov '25

Dear Osmocom community, I am pleased to announce the first usable version of my new MGW for use with OsmoBSC and E1-based BTS: https://gitea.osmocom.org/themwi/tw-e1abis-mgw This new sw component works as a drop-in replacement for osmo-mgw in the role of BSC-associated MGW for E1 Abis. Principal new features compared to OsmoMGW-E1 are: * The path from RTP input to fixed-timing TRAU-DL output passes through ThemWi jitter buffer (twjit), instead of blindly converting every received RTP packet to a TRAU-DL frame, queueing those frames to I.460 MUX Tx and hoping for the best. * For FR codec in the present implementation and for EFR coming later, a proper UL-to-DL transform (aka TFO transform) is applied to this RTP-to-DL path. This way if the stream of UL frames from the other call leg includes gaps due to radio errors, FACCH stealing or DTXu pauses, or if gaps are caused by packet loss, the stateful transform will produce proper error concealment or comfort noise insertion per TS 28.062 section C.3.2.1.1. * CSD is supported! This development may be the first time in Osmocom history of CSD working on an E1-based BTS. I tested this new MGW with Nokia InSite BTS and confirmed it working with all 3 classic GSM voice codecs (FR, HR and EFR) and with CSD up to 9600 bps. CSD at 14400 bps (D145_SYNC and EDATA frames) is supported too, but remains untested due to lack of needed support in OsmoMSC. My eventual goal is to use OsmoBSC and this new MGW with Ericsson RBS6k BTS, consisting of DUG20 and RUS or RRUS. I already have DUG20 and RUS01 hardware, but given all other work I still have to do on ThemWi CN software, I haven't got around to playing with Ericsson gear yet. My plans going forward are: * Get back to twrtp patches in Gerrit: implement the next round of changes per last round of review, and hopefully get twrtp into libosmo-netif so we can make it an option in OsmoBTS, in addition to E1 BTS. * Finish long-deferred work on libgsmhr1 in gsm-codec-lib. HRv1 codec is of course of no practical interest, can be regarded as a "just for fun" retronetworking feature, but I need to finish it so certain ThemWi components can rely on having encoders and decoders for all GSM codecs always available, and my TFO transform for HRv1 will serve as a stepping stone toward much more important TFO transform for EFR. * After the above, the big work item for me will be ThemWi-MSC. I won't get into details as I don't like writing about vaporware, but many of you know that currently I am still stuck on 2023-02 version of OsmoMSC while running newer versions of all other components. ThemWi-MSC will be my proper solution, but I'll write about it in detail only when it becomes a reality. Never stopping work toward restoration of top-quality GSM/2G networks, Mother Mychaela

2 1

Digital Frontiers: Online Platforms and Media Expansion in Uzbekistan
by vanjohnson716＠proton.me 23 Nov '25

23 Nov '25

What distinguishes Linebet Online from older platforms is its user-centric design and commitment to a seamless experience. Players can place bets across a wide range of sporting events, from football and basketball to niche competitions like darts or esports tournaments. This diversity appeals to a broader audience, catering both to seasoned bettors and newcomers looking for a straightforward entry into online gaming. In addition to variety, Linebet Online emphasizes safety and reliability. Advanced encryption protocols protect users’ data and financial transactions, ensuring that security is not sacrificed for convenience. Many platforms in the industry struggle to balance these aspects, but Linebet Online has maintained a strong reputation by prioritizing responsible gaming and regulatory compliance. This approach is essential as online betting continues to attract international attention and grow in markets where gambling has traditionally been restricted. Mobile compatibility also defines the modern betting https://jamiyatgzt.uz/ landscape. Linebet Online’s mobile app ensures that users can manage bets, monitor results, and even stream live events in real time. The integration of mobile-friendly interfaces has become a crucial factor in retaining active users, particularly among younger demographics who prefer smartphones over desktop devices for most activities. Another notable aspect of the platform is its engagement with the global community. Interactive features, such as live chats and community forums, allow users to exchange insights, discuss strategies, and share experiences. This social component transforms online betting from a solitary activity into a more communal experience. Gamification elements, including achievements, leaderboards, and rewards, further enhance user involvement, making Linebet Online more than just a betting site—it becomes a hub for entertainment and engagement. The economic impact of platforms like Linebet Online cannot be ignored either. By attracting a large international user base, these platforms contribute to local economies through taxes, affiliate programs, and partnerships. For countries looking to embrace digital entrepreneurship, the growth of online betting platforms exemplifies how technology-driven services can generate significant revenue and employment opportunities. While the excitement of online betting is apparent, experts caution that it must be approached responsibly. Educating users about risk management, promoting responsible spending, and providing support for gambling addiction are essential components of a sustainable platform. Linebet Online’s implementation of these measures demonstrates that the industry can thrive while still prioritizing the well-being of its users.

1 0

Struggling to Find the Right Assignment Writing Help? Let’s Talk!
by teves20525＠binafex.com 19 Nov '25

19 Nov '25

I’ve been exploring different options for assignment writing help lately, but the process feels more confusing than I expected. There are so many services out there—some promise quick delivery, others focus on quality but it’s hard to know which ones actually deliver on their claims. For those who’ve gone through this search before, how did you decide which service to trust? Did you rely on reviews, personal recommendations, or trial and error? I’ve also seen people recommend specific options when they needed to buy dissertation work, which made me wonder if the same tips apply to regular assignments. What red flags should I watch out for? And are there any hidden factors like customer support or revision policies that made a big difference in your experience? Visit Here: https://www.helpwithdissertation.co.uk/write-my-dissertation-proposal/

2 1

ip.access nano 3G S8 Configuration
by John Thewlis - Meath Broadband 18 Nov '25

18 Nov '25

We are trying to setup this AP as part of the 3.5G Osmocom project. We have the software stack operational and are now preparing the nano for testing. When we try to login via telnet at port 8090 we are getting a constant refusal to connect:- root@osm/openbsc/openbsc/src/ipaccess# telnet 192.168.192.30 8090 Trying 192.168.192.30... telnet: Unable to connect to remote host: Connection refused The device seems to be locked as indicated by the leds on the front panel. We have tried resetting the nano to see if this would help but to no avail. Any ideas as to how to access the device for initial configuration?. Thanks John

4 4

GPRS - local and foreign TLLIs
by Luca Melette 18 Nov '25

18 Nov '25

Hello everybody, after setting up a nanoBTS with OpenBSC/SGSN/GGSN, I had some troubles trying to connect my smartphone to the GPRS cell. Investigating the BTS-to-SGSN traffic, I saw that the frames sent by the SGSN were all marked with the same N(U) value (at LLC layer), the value was 0. With some debug, I found that the there was a mismatch in the TLLI storage, used to keep the status of attached terminals. The mentioned code is contained in gprs_llc.c, involving LL Entity functions and gprs_llc_tx_ui(). /* look-up or create the LL Entity for this (TLLI, SAPI) tuple */ lle = lle_by_tlli_sapi(msgb_tlli(msg), sapi); if (!lle) { struct gprs_llc_llme *llme; LOGP(DLLC, LOGL_ERROR, "LLC TX: unknown TLLI 0x%08x, " "creating LLME on the fly\n", msgb_tlli(msg)); llme = llme_alloc(msgb_tlli(msg)); lle = &llme->lle[sapi]; } The TX function uses the previously received TLLI to lookup for the LLE. The lle_by_tlli_sapi() performs the search, but preliminary it applies a foreign2local TLLI conversion to ensure to have a local one. Since no valid entry for the searched TLLI is found, a new one is created. And the problem is here. The new entry has the foreign TLLI. Next time the lookup fails again, and a new entry is created. This way, the counter N(U) is always reset, and the mobile do not recognize the message sequence and no attach is possible. My question is about foreign and local TLLIs. I patched the lookup, avoiding the conversion, so that the LLE is found and everything works fine... but... What is the sense of the conversion? Should the TLLI be always stored as a local one? Can this problem be solved with another foreign2local while allocating new entries? Actually, my problem has been solved with that workaround. But I'm curious to know what is the right way. Hope somebody can answer :) Thanks. Cheers, LM

4 5

Best Options for Branded Shoes in 2025?
by shahabmuhammad5656＠gmail.com 15 Nov '25

15 Nov '25

Hi everyone, I’ve been thinking about upgrading my shoe collection and wanted to get some advice. Lately, I’ve noticed so many different options in the market, but I’m specifically interested in [branded shoes](https://dealsexpress.pk/) that offer both style and durability. I usually wear casual and sports shoes, so recommendations for both types would be great. I’m also curious about which brands are currently considered worth the investment and why. Are there any particular stores or online shops you trust for authentic branded shoes? Also, how do you balance quality and price when choosing your shoes? Any personal experiences or tips would be really helpful. Thanks in advance!

1 0

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

OpenBSC November 2025