Re: Using Osmocom CNI to operate a "real" cellphone network

Kurtis Heimerl wrote: Thanks for the links. I imagine that most people on this list probably already know that my use case is very different, but perhaps some people might not know, so let me restate it briefly: I don't have the luxury of operating in a remote/rural geographical area that has NO existing cellphone services, none of any G at all - instead I live in an area where every square mm of Earth's surface is carped-bombed with super-strong 4G and 5G signals from at least 3 major carriers. Given this super-strong major carrier coverage, all mainstream sheeple with their 4G/5G smartphones are perfectly happy and satisfied, creating zero demand for community cellular networks. Instead the only people who desire a community cellular network are those who have drawn a line in the sand, said a resolute 'NO!' to all those later-G technologies and want GSM/2G service instead, for use with either historical handsets, specifically procured and acquired for nostalgia purposes, or self-made ones. I noticed one element of strangeness: in all of your articles you talked about the difficulty of acquiring real phone numbers in the operating country's PSTN numbering plan. In the first paper you wrote how a deployment in Indonesia used Swedish phone numbers instead of native Indonesian ones, in the second paper you wrote about your specific partner MNO lending you not only spectrum, but also maintaining a chokehold over your pool of phone numbers, and in the last LTE paper you wrote about specifically opting out of standard VoLTE because getting phone numbers and PSTN interconnection is so difficult and expensive. Why is it that your experiences with obtaining real phone numbers and PSTN interconnection are so sharply different from mine? Right now I can go to bulkvs.com and buy USA phone numbers (real 10-digit NANP, in the same numbering space as decades-old land lines and mainstream cell carriers) for something like $0.06 (yes, 6 _cents_) per month, with super-cheap PSTN interconnection included - super-cheap meaning $0.0003 (yes, count the zeros) per minute for inbound and $0.004 per minute for outbound. When I saw these prices for the first time about a month ago, I was shocked, I couldn't believe my eyes that traditional PSTN interconnection can be _this_ cheap - but there it is... Is this type of deal a USA-only phenomenon? Are you saying that similar deals for PSTN interconnection with real phone numbers are not available in other countries that are primary targets for building community cellular networks? Labs <rp.labs(a)gmx.ch> wrote: Yet in the context of this technical mailing list, providing correct user experience with respect to phone numbers is one of the reasons why I need to develop custom sw beyond what Osmocom already provides. At first glance, in both OsmoHLR and OsmoMSC the legacy term "extension" has already been replaced with the standard term MSISDN - thus my first naive thought was that I could enter NANP numbers as MSISDNs in the OsmoHLR database and have these MSISDNs seen natively by OsmoMSC. But the way in which the MSISDN concept is implemented in OsmoHLR/MSC currently disregards all notions of TON and NPI (type of number, numbering plan indicator), instead treating the MSISDN datum as a raw string of digits only. With all mainstream cell operators in USA, a user can dial a domestic number in 3 ways: as just 10 digits NPANXXxxxx, as 1NPANXXxxxx, or as +1NPANXXxxxx, and the network is smart enough to recognize all three as valid ways of dialing the same number. I insist on implementing the same user experience on my Themyscira Wireless network - but neither OsmoMSC's built-in MNCC nor its built-in SMSC are smart enough to handle such number nuances, hence I will need to replace both the built-in MNCC and the built-in SMS routing mechanism with my own external implementations. (I am not smart enough to implement a patch to OsmoHLR and OsmoMSC that would handle TON and NPI for MSISDN generally, beyond my own specific use case, hence I am going for external augmentation instead.) bulkvs.com provides E911 support, and so do most VoIP/SIP providers. Naturally, providing any kind of service outside of coverage area is impossible: even in those areas where T-Mobile have not shut down their GSM service yet, they will never allow my made-up IMSIs (starting with my own made-up PLMN code, *not* stepping on any assigned one) to register on their network - hence no services of any kind are possible then. The same T-Mobile who are itching to kill the last remains of their GSM network? I don't see how there can be any possibility of a roaming agreement with them - if the sole reason for We the People needing to set up our own community GSM networks is because T-Mobile are killing theirs, they certainly won't be inclined to give us roaming access to that same GSM network of theirs which they are itching to kill. Yes, they have their reasons - but I continue to argue that their approach would not be right in USA. Even if someone were building a network in a desert location with no existing services, as opposed to my very different use case, as long as that desert is located somewhere within USA where NANP phone numbers would be culturally appropriate, I argue that they should give their subscribers "the real thing". I imagine one could probably connect to/with USA phone numbers from anywhere in the world, by connecting over the Internet to a USA-based VoIP provider, but it would "feel wrong" to do it outside of USA, it would be like those Swedish phone numbers in Indonesia. "I hope you succeed" is rather meaningless without defined criteria for what counts as success. For the present phase of my project, I have set a very low bar for what I would count as success. In the present phase of my project, my goal is to demonstrate some really, really old phones to an assembled audience and show them working. Right now the oldest phone in my collection is a recently acquired Ericsson I888 (late 1990s), and I already have it connecting successfully to my Themyscira GSM network with my own Themyscira SIM - FCSIM1 programmed with my own fc-simtool. But without outside connectivity it does not "feel real" - hence my continued work to implement the necessary software for outside connectivity. Now imagine me handing this ancient 1990s phone (big and heavy as a brick) to an audience member and inviting that person to call someone with it - *that* would be impressive, and getting to that stage is what I am currently working on. All of the necessary work is software, _not_ political or regulatory etc. Once I have some working code implemented, I will upload it to a Mercurial repository on freecalypso.org and post the link. M~