5 ms·

For those interested, this project seems to be a rewrite of https://nextepc.org/ https://nextepc.org/ into Go. Alternative projects include https://github.com/f

by Jhsto 6y ago

For those interested, this project seems to be a rewrite of https://nextepc.org/ https://nextepc.org/ into Go. Alternative projects include https://github.com/facebookincubator/magma https://github.com/facebookincubator/magma and https://github.com/openairinterface https://github.com/openairinterface. You can start your own telenetwork with these projects (but of course doing such would be highly illegal without a spectrum license), but first, you need a gNB or eNodeB which is lingo for a base station. It is possible to buy an SDR and use software like https://github.com/srsLTE/srsLTE https://github.com/srsLTE/srsLTE to make the SDR receive and broadcast LTE/5G connections. After this, you need to have blank SIM cards to code. For example, this post instructs how to do so: https://cyberloginit.com/2018/05/03/build-a-lte-network-with-srslte-and-program-your-own-usim-card.html https://cyberloginit.com/2018/05/03/build-a-lte-network-with.... You might also consider writing eSIMs https://github.com/bagyenda/njiwa https://github.com/bagyenda/njiwa. After this, you should be able to use a commercial phone to connect to the network. In general, these networks function quite well even on commodity hardware. Some tests I worked on produced end-to-end latency of around 20ms on LTE, and throughput of around 7MB/s. This was using NextEPC on a 400 euro computer with a 50 euro router and a Nokia base station. Further, it was possible to make the system to work in a Heroku like manner by exposing PaaS endpoints and running Kubernetes in the access network: https://www.semanticscholar.org/paper/Open-source-RANs-in-Practice%3A-an-Over-The-Air-for-Haavisto-Arif/38aa0fcd59646de9cf54fdae812349def01fb02a https://www.semanticscholar.org/paper/Open-source-RANs-in-Pr... I think it's quite likely that sooner or later we will have 5G networks with intra-services running as edge-services, providing us low-latency. It's worth noting that with the latest LTE versions 5G and LTE access latency is virtually the same. The real latency-optimization would be, at least to my perspective, to allow software to be deployed _into_ these cellular networks to minimize network hops.

newhouseb 6y ago
I'm not an expert, but there are variants of LTE and 5G (LTE-U and 5G NR-U) that support operating in the unlicensed 5Ghz band. That said, I'm not sure a commercial handset would connect to anything in that range. You could probably get an SDR-based UE (UE is telecom-speak for "thing that connects to a cell network") to work.
- Jhsto 6y ago
  Yeah, I'm not an expert either, but there are initiatives to this as well. One such initiative is Nokia Kuha: https://www.kuha.io/ https://www.kuha.io/ The problem is exactly what you described: there are currently no commercial UE or base stations. So yeah, I suppose one is supposed to use SDR for the 5Ghz band.
  - sdjkfgsdjkfghjh 6y ago
    That site does not load here. I get a CSP error. sigh, nokia. https://www.nokia.com/networks/solutions/community-hosted-network/ https://www.nokia.com/networks/solutions/community-hosted-ne... is this the same? there is zero information about nokia kuha! interesting if this can hold more 24/7 broadband clients than wifimax et al.
    - Jhsto 6y ago
      It seems to be the same thing. The use-case displayed on Nokia's website matches to one of the blog-posts available on kuha.io
      - sdjkfgsdjkfghjh 6y ago
        thanks, it's loading here now. It seems that this is aimed exclusively at operators that already have the infrastructure to issue SIM cards et al, and communities that are barred from deploying their own infrastructure but willing to pay for it. A weird use case but clearly aimed at US and AU markets I'd guess. You need a community that will want to front the cost of laying fiber, and then instead of distributing or starting a small ISP/coop will give that new termination to a telecom giant who will plug this device into their existing billing network to provision their new subscribers with access under the existing plans costs.
- bluishscreen 6y ago
  https://translate.google.com/translate?sl=auto&tl=en&u=https%3A%2F%2Fprkele.prk.tky.fi%2Fwiki%2FHamLTE https://translate.google.com/translate?sl=auto&tl=en&u=https... Apparently, there are overlaps between common LTE bands and both ham radio bands and unlicensed (... low-power) ones... the above page states that any device with the right bands will work (... and they even got them working presumably?)
solarkraft 6y ago
> I think it's quite likely that sooner or later we will have 5G networks with intra-services running as edge-services, providing us low-latency. Noob question, sorry, but: Why not Wifi?
- Jhsto 6y ago
  LTE (and 5G on 3.6Ghz, I guess) signal can cover many kilometers. The protocols are built to be more reliable (a phone keeps a tab of access points to which it can quickly hop if access to one base station is lost) and the licensing ensures that there cannot be spectrum suffocation at any time, which is quite common in bigger cities with WiFi.
  - g_p 6y ago
    Seamless handovers are definitely key to mobile networks, and much of the 3GPP technology is designed around this. Spectrum licensing is more about ensuring exclusive use of spectrum - in a busy built up area (less common during current times hopefully), you'll still suffer from "spectrum suffocation" like with WiFi - if you ever experienced data stalling where your phone indicated a signal, but weren't getting any actual traffic through, you were on a cell that was hitting the limits of the air interface capacity. The nice part of cellular networks is that you can add more base stations using other licensed spectrum the operator has, in order to get more capacity. So with 3.5 GHz 5G bands, and wider cell widths supported, these can take some of the load in busy places. Otherwise the alternative is to deploy more base stations with lower power on each, to better and more effectively reuse the spectrum. Since the same operator runs all the equipment on their own spectrum, they can coordinate this much more effectively than ad-hoc multi operator WiFi in a congested area. The downside is the vastly increased complexity of a cellular solution (the sheer number of pages of standards), and the "entrenched player lock-in" available to legacy telecoms operators who already hold spectrum.
    - matt9j 6y ago
      In addition to just the total amount of spectrum, coordinated scheduling between towers in the cellular standards helps with cooperative management of interference. Some of this is just now happening in 802.11ax, but without the high-speed non-microwave connections that celltowers in dense areas enjoy to coordinate over. 5G-NR also allows coordinated multipoint transmission, which you can think of kind of like MIMO but from multiple towers instead of just multiple antennas on the same tower. I don't know if this would ever be feasible in consumer WiFi equipment due to the challenges of synchronizing clocks across the different APs.
non-entity 6y ago
Any recommended resources for learning about mobile communications technologies that aren't overpriced engineering certificates or surface level marketing material for / from telcoms?
- Jhsto 6y ago
  Coming from a software background, I think NextEPC and its new variant called Open5GS have the most down-to-earth documentation and code to start from: https://open5gs.org/open5gs/docs/ https://open5gs.org/open5gs/docs/. The authors have many good papers that are easy to follow. Osmocom also has good resources https://osmocom.org/projects/cellular-infrastructure/wiki https://osmocom.org/projects/cellular-infrastructure/wiki Most of the learning curve comes from the lingo. Especially now that 5G introduces softwarization of many of the network functions, the terms used by the cellular and software industries clash and may be confusing at times. But you can definitely learn the high-level idea of how the cellular networks function in this way. For physical level things, I imagine that a degree in signal processing is required. And for more advanced software interfaces, I am afraid that you can only read about them, as most devices on which the software is implemented is proprietary. The open-source software you can find is in no-way as fully implemented as the actual software which runs commercial networks.
  - non-entity 6y ago
    > the terms used by the cellular and software industries clash and may be confusing at times. lol, I've found a lot of terminology around digital communications seem to be confusing. Terms meaning two or three different things depending on context, etc.
- 14k12j41j211 6y ago
  https://www.sharetechnote.com/ https://www.sharetechnote.com/
  - non-entity 6y ago
    Oh nice, this is really cool. It even has some 802.11 stuff which I was having a hard time finding as well (apparently IEEE used to make the specs available after a certain time, but that appears to have been killed)
g_p 6y ago
Just to add to the above, some countries have very lightweight spectrum access and licensing regimes. Ofcom in the UK let you apply for a low power license (fine for around the home etc.) for a relatively nominal fee, and that will get you usable mobile spectrum - 3.3 MHz in the DECT guardband at the top end of the 1800 MHz band (FDD Band 3), or the 10 MHz slice at the top of the 2300 MHz band (2390 to 2400 MHz, which is TDD band 40). From memory, a 1-year local spectrum license should cost about £50.
mcspiff 6y ago
That’s basically what AWS has proposed with Wavelength: https://aws.amazon.com/wavelength/ https://aws.amazon.com/wavelength/
matt9j 6y ago
Magma at its initiation extended a hard fork of OAI. The projects have since diverged quite a bit, but some of the core bits are still shared. NextEPC was renamed to open5gs a while back, and a lot of the open source telecom work seems to be happening there https://github.com/open5gs/open5gs https://github.com/open5gs/open5gs . The project was recently reorganized by its founder though, and currently requires a CLA to contribute upstream.

by Jhsto 6y ago

newhouseb 6y ago

I'm not an expert, but there are variants of LTE and 5G (LTE-U and 5G NR-U) that support operating in the unlicensed 5Ghz band. That said, I'm not sure a commercial handset would connect to anything in that range. You could probably get an SDR-based UE (UE is telecom-speak for "thing that connects to a cell network") to work.

Jhsto 6y ago
Yeah, I'm not an expert either, but there are initiatives to this as well. One such initiative is Nokia Kuha: https://www.kuha.io/ https://www.kuha.io/ The problem is exactly what you described: there are currently no commercial UE or base stations. So yeah, I suppose one is supposed to use SDR for the 5Ghz band.
- sdjkfgsdjkfghjh 6y ago
  That site does not load here. I get a CSP error. sigh, nokia. https://www.nokia.com/networks/solutions/community-hosted-network/ https://www.nokia.com/networks/solutions/community-hosted-ne... is this the same? there is zero information about nokia kuha! interesting if this can hold more 24/7 broadband clients than wifimax et al.
  - Jhsto 6y ago
    It seems to be the same thing. The use-case displayed on Nokia's website matches to one of the blog-posts available on kuha.io
    - sdjkfgsdjkfghjh 6y ago
      thanks, it's loading here now. It seems that this is aimed exclusively at operators that already have the infrastructure to issue SIM cards et al, and communities that are barred from deploying their own infrastructure but willing to pay for it. A weird use case but clearly aimed at US and AU markets I'd guess. You need a community that will want to front the cost of laying fiber, and then instead of distributing or starting a small ISP/coop will give that new termination to a telecom giant who will plug this device into their existing billing network to provision their new subscribers with access under the existing plans costs.
bluishscreen 6y ago
https://translate.google.com/translate?sl=auto&tl=en&u=https%3A%2F%2Fprkele.prk.tky.fi%2Fwiki%2FHamLTE https://translate.google.com/translate?sl=auto&tl=en&u=https... Apparently, there are overlaps between common LTE bands and both ham radio bands and unlicensed (... low-power) ones... the above page states that any device with the right bands will work (... and they even got them working presumably?)

solarkraft 6y ago

> I think it's quite likely that sooner or later we will have 5G networks with intra-services running as edge-services, providing us low-latency. Noob question, sorry, but: Why not Wifi?

Jhsto 6y ago
LTE (and 5G on 3.6Ghz, I guess) signal can cover many kilometers. The protocols are built to be more reliable (a phone keeps a tab of access points to which it can quickly hop if access to one base station is lost) and the licensing ensures that there cannot be spectrum suffocation at any time, which is quite common in bigger cities with WiFi.
- g_p 6y ago
  Seamless handovers are definitely key to mobile networks, and much of the 3GPP technology is designed around this. Spectrum licensing is more about ensuring exclusive use of spectrum - in a busy built up area (less common during current times hopefully), you'll still suffer from "spectrum suffocation" like with WiFi - if you ever experienced data stalling where your phone indicated a signal, but weren't getting any actual traffic through, you were on a cell that was hitting the limits of the air interface capacity. The nice part of cellular networks is that you can add more base stations using other licensed spectrum the operator has, in order to get more capacity. So with 3.5 GHz 5G bands, and wider cell widths supported, these can take some of the load in busy places. Otherwise the alternative is to deploy more base stations with lower power on each, to better and more effectively reuse the spectrum. Since the same operator runs all the equipment on their own spectrum, they can coordinate this much more effectively than ad-hoc multi operator WiFi in a congested area. The downside is the vastly increased complexity of a cellular solution (the sheer number of pages of standards), and the "entrenched player lock-in" available to legacy telecoms operators who already hold spectrum.
  - matt9j 6y ago
    In addition to just the total amount of spectrum, coordinated scheduling between towers in the cellular standards helps with cooperative management of interference. Some of this is just now happening in 802.11ax, but without the high-speed non-microwave connections that celltowers in dense areas enjoy to coordinate over. 5G-NR also allows coordinated multipoint transmission, which you can think of kind of like MIMO but from multiple towers instead of just multiple antennas on the same tower. I don't know if this would ever be feasible in consumer WiFi equipment due to the challenges of synchronizing clocks across the different APs.

non-entity 6y ago

Any recommended resources for learning about mobile communications technologies that aren't overpriced engineering certificates or surface level marketing material for / from telcoms?

Jhsto 6y ago
Coming from a software background, I think NextEPC and its new variant called Open5GS have the most down-to-earth documentation and code to start from: https://open5gs.org/open5gs/docs/ https://open5gs.org/open5gs/docs/. The authors have many good papers that are easy to follow. Osmocom also has good resources https://osmocom.org/projects/cellular-infrastructure/wiki https://osmocom.org/projects/cellular-infrastructure/wiki Most of the learning curve comes from the lingo. Especially now that 5G introduces softwarization of many of the network functions, the terms used by the cellular and software industries clash and may be confusing at times. But you can definitely learn the high-level idea of how the cellular networks function in this way. For physical level things, I imagine that a degree in signal processing is required. And for more advanced software interfaces, I am afraid that you can only read about them, as most devices on which the software is implemented is proprietary. The open-source software you can find is in no-way as fully implemented as the actual software which runs commercial networks.
- non-entity 6y ago
  > the terms used by the cellular and software industries clash and may be confusing at times. lol, I've found a lot of terminology around digital communications seem to be confusing. Terms meaning two or three different things depending on context, etc.
14k12j41j211 6y ago
https://www.sharetechnote.com/ https://www.sharetechnote.com/
- non-entity 6y ago
  Oh nice, this is really cool. It even has some 802.11 stuff which I was having a hard time finding as well (apparently IEEE used to make the specs available after a certain time, but that appears to have been killed)

g_p 6y ago

Just to add to the above, some countries have very lightweight spectrum access and licensing regimes. Ofcom in the UK let you apply for a low power license (fine for around the home etc.) for a relatively nominal fee, and that will get you usable mobile spectrum - 3.3 MHz in the DECT guardband at the top end of the 1800 MHz band (FDD Band 3), or the 10 MHz slice at the top of the 2300 MHz band (2390 to 2400 MHz, which is TDD band 40). From memory, a 1-year local spectrum license should cost about £50.

mcspiff 6y ago

That’s basically what AWS has proposed with Wavelength: https://aws.amazon.com/wavelength/ https://aws.amazon.com/wavelength/

matt9j 6y ago

Magma at its initiation extended a hard fork of OAI. The projects have since diverged quite a bit, but some of the core bits are still shared. NextEPC was renamed to open5gs a while back, and a lot of the open source telecom work seems to be happening there https://github.com/open5gs/open5gs https://github.com/open5gs/open5gs . The project was recently reorganized by its founder though, and currently requires a CLA to contribute upstream.