Btw. as a side note, I tried using AI to solve some issues. I abandoned it, when it kept repeating that the /dev/ttyUSB4 was for AT commands (it’s 2; 4 is for audio) even after I provided correcting info. And at one point it was convinced that the modem had no audio functionality - or at least that L5 wasn’t capable of pcm audio (probably because it’s not explicitly mentioned anywhere). It got funny when I realized that it was repeating stuff from this forum as it’s main source - and most posts here are not solutions 
8 Likes
Some mmcli -m any info of sim8208g:
-----------------------------------
General | path: /org/freedesktop/ModemManager1/Modem/0
| device id: 69bde8e7507797d3f8c0bed47be3eb523fa0a174
-----------------------------------
Hardware | manufacturer: QUALCOMM INCORPORATED
| model: 0
| firmware revision: MPSS.HI.2.0.3-00269-SDX55_CPEALL_PACK-1 1 [Aug 03 2021 13:00:00]
| carrier config: Elisa_Finland
| carrier config revision: 0A015200
| h/w revision: 20000
| supported: gsm-umts, lte, 5gnr
| current: gsm-umts, lte, 5gnr
| equipment id: 861164060034834
-----------------------------------
System | device: /sys/devices/platform/soc@0/38200000.usb/xhci-hcd.4.auto/usb1/1-1/1-1.2
| physdev: /sys/devices/platform/soc@0/38200000.usb/xhci-hcd.4.auto/usb1/1-1/1-1.2
| drivers: qmi_wwan, option
| plugin: simtech
| primary port: cdc-wdm0
| ports: cdc-wdm0 (qmi), ttyUSB0 (ignored), ttyUSB1 (gps),
| ttyUSB2 (at), ttyUSB3 (at), ttyUSB4 (audio), wwu1u2i5 (net)
-----------------------------------
Status | lock: sim-pin2
| unlock retries: sim-pin (3), sim-puk (10), sim-pin2 (3), sim-puk2 (10)
| state: [connected]
| power state: on
| access tech: lte, 5gnr
| signal quality: 78% (recent)
-----------------------------------
Modes | supported: allowed: 3g; preferred: none
| allowed: 4g; preferred: none
| allowed: 3g, 4g; preferred: 4g
| allowed: 3g, 4g; preferred: 3g
| allowed: 5g; preferred: none
| allowed: 4g, 5g; preferred: 5g
| allowed: 4g, 5g; preferred: 4g
| allowed: 3g, 5g; preferred: 5g
| allowed: 3g, 5g; preferred: 3g
| allowed: 3g, 4g, 5g; preferred: 5g
| allowed: 3g, 4g, 5g; preferred: 4g
| allowed: 3g, 4g, 5g; preferred: 3g
| current: allowed: 3g, 4g, 5g; preferred: 5g
-----------------------------------
Bands | supported: utran-1, utran-3, utran-4, utran-6, utran-5, utran-8,
| utran-9, utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5,
| eutran-7, eutran-8, eutran-12, eutran-13, eutran-14, eutran-17,
| eutran-18, eutran-19, eutran-20, eutran-25, eutran-26, eutran-28,
| eutran-29, eutran-30, eutran-32, eutran-34, eutran-38, eutran-39,
| eutran-40, eutran-41, eutran-42, eutran-43, eutran-46, eutran-48,
| eutran-66, eutran-67, eutran-71, utran-19, ngran-1, ngran-2, ngran-3,
| ngran-5, ngran-7, ngran-8, ngran-12, ngran-20, ngran-28, ngran-38,
| ngran-40, ngran-41, ngran-48, ngran-66, ngran-71, ngran-77, ngran-78,
| ngran-79
| current: utran-1, utran-3, utran-4, utran-6, utran-5, utran-8,
| utran-9, utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5,
| eutran-7, eutran-8, eutran-12, eutran-13, eutran-14, eutran-17,
| eutran-18, eutran-19, eutran-20, eutran-25, eutran-26, eutran-28,
| eutran-29, eutran-30, eutran-32, eutran-34, eutran-38, eutran-39,
| eutran-40, eutran-41, eutran-42, eutran-43, eutran-46, eutran-48,
| eutran-66, eutran-67, eutran-71, utran-19, ngran-1, ngran-2, ngran-3,
| ngran-5, ngran-7, ngran-8, ngran-12, ngran-20, ngran-28, ngran-38,
| ngran-40, ngran-41, ngran-48, ngran-66, ngran-71, ngran-77, ngran-78,
| ngran-79
-----------------------------------
IP | supported: ipv4, ipv6, ipv4v6
-----------------------------------
3GPP | imei: [redacted]
| enabled locks: fixed-dialing
| operator id: 24405
| operator name: FI elisa
| registration: home
| packet service state: attached
-----------------------------------
3GPP EPS | ue mode of operation: csps-2
| initial bearer path: /org/freedesktop/ModemManager1/Bearer/0
| initial bearer apn: internet
| initial bearer ip type: ipv4v6
-----------------------------------
SIM | primary sim path: /org/freedesktop/ModemManager1/SIM/0
| sim slot paths: slot 1: /org/freedesktop/ModemManager1/SIM/0 (active)
| slot 2: none
-----------------------------------
Bearer | paths: /org/freedesktop/ModemManager1/Bearer/2
| /org/freedesktop/ModemManager1/Bearer/1
4 Likes
Woah, this is awesome, so this talk about us being able to keep our phone current (without needing to throw it away and buy new ones all the time) is not just marketing, it’s actually real! 
So far, I got my phone in 2022, and in three years I’ve replaced the wi-fi card with a better one, replaced the battery to have as-new battery life, replaced a damaged USB board, and it looks like I may replace the 4G modem with one that supports 5G in the near future. And I’m thinking of changing to another Linux distribution (Mobian).
Don’t think I could have done much, or indeed any, of that on my old Samsung phone.
8 Likes
Just for funzies, as the Dl speed is quite good already, I got to wondering: how fast could L5 download, in theory? The sim8202g has theoretical limits of 2.4Gbps(DL)/500Mbps(UL) for “sub-6G” (which I take to meaning 5G specific frequencies and protocols) and 1Gbps(DL)/200Mbps(UL) using LTE (which it seem to be doing in my current network and with L5’s antennas). This is much faster than the theoretical upper limits of bm818, 150/50. Real world is never as fast and L5 has adequate but less than super optimal antennas.
But setting those aside, what internal parts are the bottleneck? I have a hunch that L5 (and any currently existing phone for that matter) is not able to handle 1Gbps or 2.4Gbps top speeds of data download. Upload speeds either - maybe peak, but not consistently. Is the USB setting the limits for this (somewhere around 200-480Mbps range, maybe), as it does with the memory card? Or is it something else?
2 Likes
Yes.
Absolute theoretical limit 480 Mbit/sec. Real world limit somewhat lower. (There’s no point having a 5G modem from the point of view of download speed.)
Random question … and I apologise if you already answered but … how do you know for sure that the modem is actually using 5G for voice? for data? (given that the modem also supports 4G)
One answer to that might be “you chose the mode where only 5G is allowed”. Another answer to that is that you issued the command AT+BMRAT during a voice call / not during a voice call and it clearly indicated that 5G was in use. A third possible answer is that the plan associated with your SIM is 5G-only (but I would be a little surprised if providers were offering that - certainly in my country we are still a million miles from 5G-only being viable).
For privacy reasons therefore you would never want to connect ANT2 with this modem.
That by itself is a win for some Librem 5 customers, and probably a win for Purism if they want to switch over to a global modem.
4 Likes
Well, it is faster and more stable too. Bm818 couldn’t reach the potential maximum.
Interesting point. I’ve been so caught up on having a stable modem (the bm818 has never worked well for me here) that I’ve yet to do much testing. I’m pretty sure the actual connections - especially data - is via LTE (at better speed and stability than before). 5G comes from how the system sees it as it identifies if it’s connected via 3G, 4G or 5G (looking at upper left corner of screen). My settings are automatically “3G, 4G, 5G (preferred)” and it never drops from 5G. What I’d question here is that, due to L5 antennas, it must use the freq areas same or close to 4G (as the 5G special frequences are not available - but those are only part of the whole) but it’s using 5G protocols and algorithms to manage the signals, datastreams and network use.
When I now tested it, it still retains network connectivity but gives no 5G marking when selecting “5G only” and voice call fails. It does give 4G when selecting “4G only” [meaning also that if someone wants to limit the modem not to use 5G, it works well without it]. yet, when I select the “3G, 4G, 5G (preferred)”, it shows 5G for network. This seems like the logic is that 5G can not function without 4G (probably due to Volte needing LTE data), at least in this network. As for further testing, I’m open for suggestions (of the previous, number one done, two is a bit redundant, three is not possible) but I think more can be learnt if we’d understand how the system interprets 5G (what does it - or standards regarding 5G - consider to be 5G in order to show that symbol).
[edit to add: quick test with using ANT1 too (and additional external antenna) didn’t produce anything new on 5G so I surmise that having extra antennas does not bring 5G - it’s something else (extra antennas are not connected to frequencies or bands available, they are separate channels if I understand the manual correctly). A slight increase in DL speeds - even a bit over 200Mbps single temporary peak.]
Same with bm818 (it has three antenna connectors) and most other modems as well.
5 Likes
Truly inspiring result!
Just two questions:
- Where are you get the additional antenna? Was it sold together with the modem or separately?
- You mentioned about GNSS functionality. Are you trying to get satellites data? In my case L5 GNSS module shows only GPS ones, no GLONASS or BeiDou at all. So, the modem could improve this point too :).
2 Likes
That doesn’t sound good. (The term, VoLTE, tends to be used even when using 5G but maybe that indicates that the modem firmware can’t do calls over actual 5G and wants to drop down to 4G.)
Even so, that is exactly why you would want to use AT+BMRAT
1 Like
They (I have couple different - small flat to fit inside L5 back cover, a 30cm table antenna etc.) are from online radio stores. The connector is standard and there are adapters to connect even larger externals to it. I wasn’t about the specs - “works for3G/ 4G” was enough as that covers most fregs and all that the modem manual has listed. They look ridiculous and since I live in a city, there’s no real need for them to get signal.
GNSS is something I’m not testing on the modem. I’m not sure if the L5 would even receive it, how the wiring is done, since it has a separate receiver for that. For all I know, it’s only the network operator (and bad actors) that even could get that info then from the modem. True, there is potential there but it does go against the L5 security fencing of the modem.
4 Likes
I may try that. But if you missed it, the one AT command that I did check and use was “AT+VOLTESETTING=1” that the modem has. As it’s not documented, I’m not sure if it’s to enable “Volte only” or “possible to use Volte”. (it’s probably the equivalent of the BMRAT)
And what’s the definition, is Volte for 4G only or is it what 5G also uses? Noting, “VoLTE = Voice over LTE”.
[edit ot add: for a deepdive into VoLTE vs. VoNR (the 5G upgrade that is still rolled out and needs devices that suport it), see VoLTE vs. Vo5G (VoNR): A Comprehensive Technical Comparison - Cafetele Telecom Training Sim8202 supports both SA and NSA modes, so it should (?) potentially be able to do VoNR… if everything else supports it too (my network maybe uses 5G VoLTE for instance) - and I’m not sure if my current setup is using it (how would the user even know as 5G uses VoLTE too and the quality is so good with both that it’s impossible for a normal human to tell them apart - the loudspeaker may be the limitation)]
3 Likes
The datasheet says that GLONASS and BeiDou are mutually exclusive, but I don’t know how to switch your choice between them.
2 Likes
Librem 5’s module supports GPS, GLONASS, Galileo, QZSS and BeiDou, with SBAS augmentation (though GLONASS and BeiDou are mutually exclusive unless all other constellations are disabled). If you don’t see other constellations, they’re probably disabled in the module’s configuration. Following the instructions at Assisted GNSS ($1207) · Snippets · GitLab will enable them (GPS, Galileo and BeiDou to be exact, but changing the bitmask is trivial).
I’m not sure how a BroadMobi’s custom command could be useful there.
6 Likes
Oops, yes. Need to discover the equivalent command for this modem in order to work out what is actually in use at any given time. Otherwise it’s just guesswork.
2 Likes
It is true, but not for me 
I even downloaded the original datasheet and protocol specification to manipulate the bitmask, but I never able to see more satellites… I will try again when make Crimson backports be ready for upgrading my Byzantium backports installation, but I have no illusions about. Thanks for the link and sorry for offtopic 
1 Like
Btw. I’m not associated with this entity, but it seems like it should be mentioned that someone has a pile of these modems used on eBay for a more decent price (from Germany): SIMCom SIM8202G-M2 M.2 Multi-Band 3G/4G/LTE/5G NR/LTE-FDD/LTETDD/HSPA+ _0.008_6 | eBay
2 Likes
Yeah, it never makes a ring sound. There is no default sound file.
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So is this implying that 5G data does work? Even that would be progress. It would future-proof the phone and you could still make calls using VoIP. (I understand that it’s not that big a deal because 4G isn’t going to disappear soon.)
The modem may just be lacking some configuration data.
I guess one question that comes up for me is … how good is the support from the manufacturer? is it possible to get answers to some of the questions that have come up in this topic? can the firmware be updated? how is that done? are new firmware versions forthcoming?
2 Likes
Searching the internet for “Sim8202G AT commands” turns up some results.
2 Likes
I will pick this one up in a couple of paychecks.
3 Likes