7 ms·

> They're using a base OEM model from someone that happens to have opensource drivers for everything (which makes me think it's an older model). I... don't thi

> They're using a base OEM model from someone that happens to have opensource drivers for everything (which makes me think it's an older model). I... don't think that's the case here. In the specifications they state: CPU separate from Baseband My reading is that modem is connected to the CPU via USB. The only other project I know of that was looking at doing such a thing were the OpenMoko guys (GTA04 with an OMAP3xxx, I think? My memory is fuzzy on this). AFIAK, there are no 3G/4G modems with an open source baseband. So the traditional route for libre/privacy conscious people has been to isolate the baseband from the application processor via USB. Normal phones have the baseband and SoC integrated on the same SoC and connected via a high speed serial bus. On further reading, it's going to be an i.MX6 (because i.MX8 is not available yet and you don't typically use unreleased SoCs for your libre hardware) which is pretty inefficient by modern ARM SoC standards. So this is essentially a small tablet running Linux with an integrated cellular modem.

sounds 9y ago
Yup. On their site: "will work with 2G/3G/4G, GSM, UMTS, and LTE" If it's using something like this: http://a.co/9IVPmkI http://a.co/9IVPmkI -- then maybe it's using the USB pins on a mini PCIe card. I think it would be wise to wait until they have committed to a particular cell modem. Most people will not be able to use a phone day to day if it suffers from: • Dropped calls • Bad call quality • Low speed data (anything less than 4G/LTE)
- kogepathic 9y ago
  > then maybe it's using the USB pins on a mini PCIe card. Every mini-PCIe cellular modem I've seen interfaces via USB and not via native PCIe. You can even buy adapters to use a mini-PCIe modem as a USB modem. [0] I don't think this is standardized, but it seems to be the defacto standard for all modems in this form factor. Now this may change once LTE/5G speeds regularly exceed what USB 2.0 is capable of since mini-PCIe does not provide pins for USB 3.0, the standard is too old. I would guess they'll move to NGFF as that's already the case for newer business notebooks which offer a WWAN slot. [0] https://www.amazon.com/PCI-E-Adapter-Module-Support-connector/dp/B01FCU61TG/ https://www.amazon.com/PCI-E-Adapter-Module-Support-connecto...
- notspanishflu 9y ago
  This is that link without the reference https://www.amazon.com/dp/B00NPX09QY/ https://www.amazon.com/dp/B00NPX09QY/
rsync 9y ago
"My reading is that modem is connected to the CPU via USB. The only other project I know of that was looking at doing such a thing were the OpenMoko guys (GTA04 with an OMAP3xxx, I think? My memory is fuzzy on this)." First, modem connected via USB is a good thing - it's the least bad option with regard to closed basebands. Second, it's not that rare of a configuration - I believe there are quite a few consumer smartphones that connect the baseband via a USB interface ... it's not like there's a little USB connector inside there... "So this is essentially a small tablet running Linux with an integrated cellular modem." I don't think that's exactly correct ... It is indeed possible to stick a USB cellular modem onto a tablet device and even use it for telephony. The problem with this arrangement is that there are many other things (like echo cancellation and other voice enhancements that need realtime processing) the baseband processor does - and you lose those functions. An integrated USB modem that is actually the integrated baseband of a mobile phone does not have those problems - even though the bus used is USB.
timonovici 9y ago
It will most likely be a USB-like connection; HSIC, I suppose. BTW, this is the condition that all Replicant phones have to meet in order to be ported to it. So quite a lot of phones already have such an architecture.
timonovici 9y ago
https://redmine.replicant.us/boards/33/topics/7383?r=7569 https://redmine.replicant.us/boards/33/topics/7383?r=7569
rhn_mk1 9y ago
At least the Nokia N900 used the separate CPU and baseband configuration. The osmocombb project [0] is an implementation of baseband modem functionality, but I'm not aware of anyone using it. Old TI Calypso modems also have an open source firmware implementation [1]. [0] http://osmocom.org/projects/baseband http://osmocom.org/projects/baseband [1] http://www.freecalypso.org http://www.freecalypso.org
NoGravitas 9y ago
> So this is essentially a small tablet running Linux with an integrated cellular modem. This reminds me that the 3G version of the 2012 Nexus 7 tablet had the baseband processor separate from the CPU. It was generally said that this was one of the reasons it had sub-par battery life, but I don't know if that was true.

sounds 9y ago

Yup. On their site: "will work with 2G/3G/4G, GSM, UMTS, and LTE" If it's using something like this: http://a.co/9IVPmkI http://a.co/9IVPmkI -- then maybe it's using the USB pins on a mini PCIe card. I think it would be wise to wait until they have committed to a particular cell modem. Most people will not be able to use a phone day to day if it suffers from: • Dropped calls • Bad call quality • Low speed data (anything less than 4G/LTE)

kogepathic 9y ago
> then maybe it's using the USB pins on a mini PCIe card. Every mini-PCIe cellular modem I've seen interfaces via USB and not via native PCIe. You can even buy adapters to use a mini-PCIe modem as a USB modem. [0] I don't think this is standardized, but it seems to be the defacto standard for all modems in this form factor. Now this may change once LTE/5G speeds regularly exceed what USB 2.0 is capable of since mini-PCIe does not provide pins for USB 3.0, the standard is too old. I would guess they'll move to NGFF as that's already the case for newer business notebooks which offer a WWAN slot. [0] https://www.amazon.com/PCI-E-Adapter-Module-Support-connector/dp/B01FCU61TG/ https://www.amazon.com/PCI-E-Adapter-Module-Support-connecto...
notspanishflu 9y ago
This is that link without the reference https://www.amazon.com/dp/B00NPX09QY/ https://www.amazon.com/dp/B00NPX09QY/

rsync 9y ago

"My reading is that modem is connected to the CPU via USB. The only other project I know of that was looking at doing such a thing were the OpenMoko guys (GTA04 with an OMAP3xxx, I think? My memory is fuzzy on this)." First, modem connected via USB is a good thing - it's the least bad option with regard to closed basebands. Second, it's not that rare of a configuration - I believe there are quite a few consumer smartphones that connect the baseband via a USB interface ... it's not like there's a little USB connector inside there... "So this is essentially a small tablet running Linux with an integrated cellular modem." I don't think that's exactly correct ... It is indeed possible to stick a USB cellular modem onto a tablet device and even use it for telephony. The problem with this arrangement is that there are many other things (like echo cancellation and other voice enhancements that need realtime processing) the baseband processor does - and you lose those functions. An integrated USB modem that is actually the integrated baseband of a mobile phone does not have those problems - even though the bus used is USB.

timonovici 9y ago

It will most likely be a USB-like connection; HSIC, I suppose. BTW, this is the condition that all Replicant phones have to meet in order to be ported to it. So quite a lot of phones already have such an architecture.

timonovici 9y ago

https://redmine.replicant.us/boards/33/topics/7383?r=7569 https://redmine.replicant.us/boards/33/topics/7383?r=7569

rhn_mk1 9y ago

At least the Nokia N900 used the separate CPU and baseband configuration. The osmocombb project [0] is an implementation of baseband modem functionality, but I'm not aware of anyone using it. Old TI Calypso modems also have an open source firmware implementation [1]. [0] http://osmocom.org/projects/baseband http://osmocom.org/projects/baseband [1] http://www.freecalypso.org http://www.freecalypso.org

NoGravitas 9y ago

> So this is essentially a small tablet running Linux with an integrated cellular modem. This reminds me that the 3G version of the 2012 Nexus 7 tablet had the baseband processor separate from the CPU. It was generally said that this was one of the reasons it had sub-par battery life, but I don't know if that was true.