Hello Osmocom community,
Is there anyone here who uses Osmocom CNI software to operate a "real" cellular phone network (2G or 3G or both) anywhere in USA, or am I going to be the first? By "real", I mean operating a cellular phone network that strives to provide a user experience to its subscribers that is as close as possible to what one would get from a "regular" operator like AT&T or T-Mobile, aside from much much smaller coverage area, perhaps as small as the operator's house and its immediate surroundings. But aside from the tiny coverage area, all other aspects of user experience need to be fully "real": each subscriber gets a real 10-digit phone number in the North American Numbering Plan, can receive calls and SMS at this number, and can place calls and send SMS to the outside world, with the user's real NANP number appearing as the source. The principal difference from a self-contained classic NITB setup is that subscribers' MSISDNs are real NANP, rather than made-up "extension" numbers, plus a PSTN gateway implementation for outside connectivity.
Is there anyone in USA (or anywhere else in the world, substituting your country's "real" numbering plan for NANP) who operates an Osmocom CNI network in this manner? If there isn't, I will be happy to be the first, and I will also be quite happy to publish the source for all of the custom sw components I'm going to develop for this task - which I plan to implement as add-ons to Osmocom CNI, connecting via MNCC, SMPP and GSUP interfaces, rather than patches to Osmocom sw components themselves. However, if I am not the first to embark on such a venture, it would be nice to know how others have done it before me, so I can make a more informed decision as to what I can reuse vs which wheels I would rather reinvent per my own taste.
Someone please correct me if I'm wrong, but it is my understanding that Rhizomatica (the most "real" and "production" user of Osmocom CNI I know of) does things differently from what I envision: aside from being in Mexico rather than USA (hence no NANP), it is my understanding (again, someone please correct me if I'm wrong) that they don't give their individual subscribers (end users) direct phone numbers in the Mexican numbering plan, directly reachable from anywhere in the world as +52-xxxxx, instead subscribers get "extension" numbers that are meaningful only inside those special village networks. In other words, a PBX-style network like the inside of a company with phone extensions, rather than direct PSTN phone numbers.
I currently plan on using bulkvs.com as my North American PSTN connectivity back-end provider with real NANP phone numbers, at least for voice - I haven't found a solution for P2P SMS connectivity yet, but because of the complexity of the task, I decided to break it into pieces and focus on just voice at first. However, if someone else has already done something similar, operating your own cellular network where your subscribers get real 10-digit NANP phone numbers instead of just internal extensions, I would be interested in knowing whom you use (or used) as your back-end provider for PSTN connectivity and source of phone numbers, and if anyone was able to get P2P SMS included in the deal.
M~
Hi Mychaela,
I'd consider Rhizomatica the most successful, but we have run Osmocom with paying subscribers a few times, notably in Indonesia (https://kurti.sh/pubs/vbts_itid_15.pdf) and the Philippines (https://kurti.sh/pubs/Scaling_Community_Cellular_Networks.pdf). Neither of these are operational at the moment, having been deprecated for LTE instead (https://kurti.sh/pubs/CoLTE_Mobicom_2019.pdf). However, each included significant engineering efforts that may be useful for your own deployment. It can definitely be done and we used a bulk SIP-Based Voice/SMS provider (Nexmo, now vonage) to do it.
On Sat, Jun 4, 2022 at 10:35 PM Mychaela Falconia mychaela.falconia@gmail.com wrote:
Hello Osmocom community,
Is there anyone here who uses Osmocom CNI software to operate a "real" cellular phone network (2G or 3G or both) anywhere in USA, or am I going to be the first? By "real", I mean operating a cellular phone network that strives to provide a user experience to its subscribers that is as close as possible to what one would get from a "regular" operator like AT&T or T-Mobile, aside from much much smaller coverage area, perhaps as small as the operator's house and its immediate surroundings. But aside from the tiny coverage area, all other aspects of user experience need to be fully "real": each subscriber gets a real 10-digit phone number in the North American Numbering Plan, can receive calls and SMS at this number, and can place calls and send SMS to the outside world, with the user's real NANP number appearing as the source. The principal difference from a self-contained classic NITB setup is that subscribers' MSISDNs are real NANP, rather than made-up "extension" numbers, plus a PSTN gateway implementation for outside connectivity.
Is there anyone in USA (or anywhere else in the world, substituting your country's "real" numbering plan for NANP) who operates an Osmocom CNI network in this manner? If there isn't, I will be happy to be the first, and I will also be quite happy to publish the source for all of the custom sw components I'm going to develop for this task - which I plan to implement as add-ons to Osmocom CNI, connecting via MNCC, SMPP and GSUP interfaces, rather than patches to Osmocom sw components themselves. However, if I am not the first to embark on such a venture, it would be nice to know how others have done it before me, so I can make a more informed decision as to what I can reuse vs which wheels I would rather reinvent per my own taste.
Someone please correct me if I'm wrong, but it is my understanding that Rhizomatica (the most "real" and "production" user of Osmocom CNI I know of) does things differently from what I envision: aside from being in Mexico rather than USA (hence no NANP), it is my understanding (again, someone please correct me if I'm wrong) that they don't give their individual subscribers (end users) direct phone numbers in the Mexican numbering plan, directly reachable from anywhere in the world as +52-xxxxx, instead subscribers get "extension" numbers that are meaningful only inside those special village networks. In other words, a PBX-style network like the inside of a company with phone extensions, rather than direct PSTN phone numbers.
I currently plan on using bulkvs.com as my North American PSTN connectivity back-end provider with real NANP phone numbers, at least for voice - I haven't found a solution for P2P SMS connectivity yet, but because of the complexity of the task, I decided to break it into pieces and focus on just voice at first. However, if someone else has already done something similar, operating your own cellular network where your subscribers get real 10-digit NANP phone numbers instead of just internal extensions, I would be interested in knowing whom you use (or used) as your back-end provider for PSTN connectivity and source of phone numbers, and if anyone was able to get P2P SMS included in the deal.
M~
Hello Mychaela,
First would be good to talk to FCC when you apply for commercial frequency, what requirements they have.
The numbering format is the last of your issues. If you provide a telephone service with a real number for dial out/in you must have also emergency services working. If you are a really small operator maybe you will not be required to have lawful interception but in your country you never know unless you discuss it with authorities.
What is happening if your subscriber is outside of your coverage area and wants dial another number? Maybe you will need some local roaming agreements with the big operators.
There is a reason why the other networks running opensource mobile networks like Rhizomatica don't use real numbering plan and keep the networks isolated.
Good luck, I hope you succeed. Let us know the results.
Regards, R.
On 05/06/2022 07:35, Mychaela Falconia wrote:
Hello Osmocom community,
Is there anyone here who uses Osmocom CNI software to operate a "real" cellular phone network (2G or 3G or both) anywhere in USA, or am I going to be the first? By "real", I mean operating a cellular phone network that strives to provide a user experience to its subscribers that is as close as possible to what one would get from a "regular" operator like AT&T or T-Mobile, aside from much much smaller coverage area, perhaps as small as the operator's house and its immediate surroundings. But aside from the tiny coverage area, all other aspects of user experience need to be fully "real": each subscriber gets a real 10-digit phone number in the North American Numbering Plan, can receive calls and SMS at this number, and can place calls and send SMS to the outside world, with the user's real NANP number appearing as the source. The principal difference from a self-contained classic NITB setup is that subscribers' MSISDNs are real NANP, rather than made-up "extension" numbers, plus a PSTN gateway implementation for outside connectivity.
Is there anyone in USA (or anywhere else in the world, substituting your country's "real" numbering plan for NANP) who operates an Osmocom CNI network in this manner? If there isn't, I will be happy to be the first, and I will also be quite happy to publish the source for all of the custom sw components I'm going to develop for this task - which I plan to implement as add-ons to Osmocom CNI, connecting via MNCC, SMPP and GSUP interfaces, rather than patches to Osmocom sw components themselves. However, if I am not the first to embark on such a venture, it would be nice to know how others have done it before me, so I can make a more informed decision as to what I can reuse vs which wheels I would rather reinvent per my own taste.
Someone please correct me if I'm wrong, but it is my understanding that Rhizomatica (the most "real" and "production" user of Osmocom CNI I know of) does things differently from what I envision: aside from being in Mexico rather than USA (hence no NANP), it is my understanding (again, someone please correct me if I'm wrong) that they don't give their individual subscribers (end users) direct phone numbers in the Mexican numbering plan, directly reachable from anywhere in the world as +52-xxxxx, instead subscribers get "extension" numbers that are meaningful only inside those special village networks. In other words, a PBX-style network like the inside of a company with phone extensions, rather than direct PSTN phone numbers.
I currently plan on using bulkvs.com as my North American PSTN connectivity back-end provider with real NANP phone numbers, at least for voice - I haven't found a solution for P2P SMS connectivity yet, but because of the complexity of the task, I decided to break it into pieces and focus on just voice at first. However, if someone else has already done something similar, operating your own cellular network where your subscribers get real 10-digit NANP phone numbers instead of just internal extensions, I would be interested in knowing whom you use (or used) as your back-end provider for PSTN connectivity and source of phone numbers, and if anyone was able to get P2P SMS included in the deal.
M~
Kurtis Heimerl wrote:
I'd consider Rhizomatica the most successful, but we have run Osmocom with paying subscribers a few times, notably in Indonesia
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.
However, each included significant engineering efforts that may be useful for your own deployment. It can definitely be done and we used a bulk SIP-Based Voice/SMS provider (Nexmo, now vonage) to do it.
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@gmx.ch wrote:
The numbering format is the last of your issues.
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.)
If you provide a telephone service with a real number for dial out/in you must have also emergency services working.
bulkvs.com provides E911 support, and so do most VoIP/SIP providers.
What is happening if your subscriber is outside of your coverage area and wants dial another number?
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.
Maybe you will need some local roaming agreements with the big operators.
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.
There is a reason why the other networks running opensource mobile networks like Rhizomatica don't use real numbering plan and keep the networks isolated.
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.
Good luck, I hope you succeed.
"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.
Let us know the results.
Once I have some working code implemented, I will upload it to a Mercurial repository on freecalypso.org and post the link.
M~
Comments in line:
On Mon, Jun 6, 2022 at 4:39 PM Mychaela Falconia mychaela.falconia@gmail.com wrote:
Kurtis Heimerl wrote:
I'd consider Rhizomatica the most successful, but we have run Osmocom with paying subscribers a few times, notably in Indonesia
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.
Mayhaps, but we're currently running an LTE-based community network here in Seattle (https://seattlecommunitynetwork.org/) and seeing uptake from exactly those types of folks.
However, each included significant engineering efforts that may be useful for your own deployment. It can definitely be done and we used a bulk SIP-Based Voice/SMS provider (Nexmo, now vonage) to do it.
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.
Numbers outside the US can vary quite a bit in their availability and cost. It should be a lot easier in the US. For VoLTE, there are other technical concerns that remain unsolved; I agree access to numbers is not an issue.
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?
They seem like a good vendor and things have gotten a lot better than the times when we were producing that work.
Labs rp.labs@gmx.ch wrote:
The numbering format is the last of your issues.
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.)
If you provide a telephone service with a real number for dial out/in you must have also emergency services working.
bulkvs.com provides E911 support, and so do most VoIP/SIP providers.
What is happening if your subscriber is outside of your coverage area and wants dial another number?
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.
Maybe you will need some local roaming agreements with the big operators.
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.
There is a reason why the other networks running opensource mobile networks like Rhizomatica don't use real numbering plan and keep the networks isolated.
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.
Good luck, I hope you succeed.
"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.
Let us know the results.
Once I have some working code implemented, I will upload it to a Mercurial repository on freecalypso.org and post the link.
M~
Kurtis Heimerl wrote:
Mayhaps, but we're currently running an LTE-based community network here in Seattle (https://seattlecommunitynetwork.org/)
Are you running it in CBRS band? I found only one page on your website that makes a passing reference to CBRS, hence asking to be certain. You don't run any services in either of the two traditional bands (AMPS/GSM850 and PCS), do you?
and seeing uptake from exactly those types of folks.
What do you mean by "those types of folks"? The "type of folks" I was referring to are anti-smartphone, anti-4G/5G/etc conscientious objectors, those who refuse to own or use any kind of 4G (or newer) device - how can these "type of folks" possibly use your network if you only operate LTE, the "enemy" technology which people of my kind want nothing to do with? Hence I reason that you probably meant something different by "those types of folks" - but what?
M~
-
Kurtis Heimerl -
Labs -
Mychaela Falconia