@trendbook wrote:

Ideal would be:

A, A 4G capable cell phone that has an antenna connection like the old 2G Nokia

No, that is not an ideal solution.

If the external antenna is not equipped with an LNA (=> which is the case in 99.99% of all mobile phone external antennas with (RP-)SMA-Anschluss), the signal losses caused by the long antenna cable are so serious that mobile phone reception is severely impaired. For further arguments see the articles linked above. Long antenna cables to an outdoor antenna should generally only be used if an LNA or LNB directly on the outdoor antenna amplifies the received signal!

[/t5/Mobile/Abschaltung-Frequenzen-3G-amp-2G/m-p/612337#M7150](https://community.swisscom.ch/t5/Mobile/Abschaltung-Frequenzen-3G-amp-2G/m-p/612337 #M7150)

The ideal solution would be a cell phone repeater to improve in-house cell phone reception. See also:

https://community.swisscom.ch/t5/Mobile/Abbruch-des-telefonat/m-p/636411

[https://www.bakom.admin.ch/bakom/de/home/geraete-anlagen/besondere-geraete/mobilfunk-verstaerker.html](https://www.bakom.admin.ch/bakom/de/ home/devices-systems/special-devices/mobile-radio-amplifiers.html)

Swisscom does not offer private customers a mobile phone repeater. Private customers are only allowed to use passive mobile phone repeaters. See (also note page 2!):

https://community.swisscom.ch/t5/Mobile/Passive-Signalumlenkung/m-p/668125

Cell phones with Anschluss for an external cell phone antenna were available in the age when cell phones still had a “rubber sausage” as a cell phone antenna. And the cell phones support one, at most two cellular frequency bands (900 + 1800 MHz).

https://de.wikipedia.org/wiki/Gummiwurst

Mobile phones with a mobile phone antenna protruding from the housing (for example: "rubber sausage) are undesirable among customers. This means that you will most likely not find a 4G/LTE-capable mobile phone on the market that has a Anschluss for an external mobile phone antenna.

http://ewh.ieee.org/r2/no_virginia/aps/DL_small_antennas_PDF.pdf

In addition, practically all modern cell phones today have 2 internal cell phone antennas installed. So that the advantages of antenna diversity can be fully exploited when sending and receiving the mobile signal.

[https://www.lancom-forum.de/lancom-wireless-aktuelle-accesspoints-f35/leitungsabbrueche-im-wlan-t17257.html#p98059](https://www.lancom-forum.de/lancom- wireless-current-accesspoints-f35/connection-aborts-im-wlan-t17257.html#p98059)

[https://www.lancom-forum.de/lancom-wireless-aktuelle-accesspoints-f35/l-321-mit-repeater-schneller-als-ohne-t16822.html#p95263] (https://www.lancom-forum.de/lancom-wireless-aktuelle-accesspoints-f35/l-321-mit-repeater-schneller-als-ohne-t16822.html#p95263)

This is the reason why good, 4G/LTE-capable cellular routers have two (RP) SMA antenna connections for two (cross-polarized) external antennas!

@trendbook wrote:

B, A router/gateway that turns the prepaid SIM card into an analogue telephone again

If an analog telephone is to be connected, a converter should be used which uses a SIP client to convert VoIP telephony into analog telephony. For example: Cisco SPA112. I consider the use of such converters to be “not recommended” for various reasons!

@trendbook wrote:

What actually happens on the 2G frequencies that become available? Will the 4G stay where it is or will 4G also be broadcast on the frequencies that become available so that he can possibly continue to use his antenna?

The cellular frequencies used for 2G/GSM will be used for 4G/LTE or 5G in the near future. See the Wikipedia article linked above.

Show original language (German)

If voice telephony takes place via LTE/4G without the use of VoLTE (Voice over LTE => VoIP voice telephony over the 4G/LTE mobile network with SIP/RTP), there is no QoS for voice telephony over the LTE mobile network. Similar to WLAN transmission, this leads to a loss in the voice quality of voice telephony.

For the best voice quality for voice telephony, a VoLTE-capable VoIP gateway should be used in the alpine hut. These are also called “Session Border Controllers” (SBC) and have firewall-like tasks for VoIP telephony.

https://de.wikipedia.org/wiki/Session_Border_Controller

[https://www.lancom-systems.de//download/documentation/Whitepaper/WP-Session-Border-Controller-DE.pdf](https://www.lancom-systems.de//download/documentation/ Whitepaper/WP-Session-Border-Controller-DE.pdf)

An example of a VoLTE-capable SBC is the beroNet VoLTE SBC:

https://www.beronet.com/de/gateway/volte-sbc/

Another example of a VoLTE-capable VoIP gateway is the Zyxel LTE3316-M604:

[https://www.zyxel.com/de/de/products\_services/4G-LTE-A-Indoor-IAD-LTE3316-M604/](https://www.zyxel.com/de/de/products_services /4G-LTE-A-Indoor-IAD-LTE3316-M604/)

However, the total costs of such a VoLTE-capable VoIP gateway should be considered over the entire lifespan of the VoIP gateway. The cheapest data package offer for Swisscom prepaid SIM cards costs CHF 4.90 per month (combi package S). That’s 59.- CHF per year in “subscription costs” for the “alpine hut internet connection” (if you visit the alpine hut all year round). I described the possible and recommended structure of the “alpine hut internet connection” in article no. 2. This means that VoIP telephony via the “alpine hut internet connection” is probably significantly cheaper than voice telephony via a (relatively expensive) VoLTE-capable VoIP gateway.

Be careful when using prepaid SIM cards from the mobile phone provider Swisscom: Prepaid SIM cards from Swisscom do not (yet) support VoLTE or VoWLAN! See:

[/t5/Mobile/Callfilter-f%C3%BCr-Mobiltelefone-against-unerw%C3%BCnschte-Advertising Calls/m-p/616781#M7377](https://commu nity.swisscom.ch/t5/Mobile/Callfilter-f%C3%BCr-Mobiltelefone-gegen-unerw%C3%BCnschte-Werberufe/m-p/616781#M7377)

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In this case, I would also use a mobile phone repeater that can repeat at least UMTS 900 and LTE 800. Or order the basic service product from Swisscom. That just costs 25 CHF/month, but Swisscom then ensures that the installation runs either via 4G or via satellite.

Show original language (German)

Swisscom will cover the additional costs for installation and communication - that’s how I understand the basic service mandate. The customer simply pays the 25.35 CHF/month and the call costs for a simple telephone. But they are the same depth, whether there is copper, glass, LTE or satellite in between, it doesn’t matter.

Show original language (German)

You can find information on the topic of “basic supply of alpine huts with voice telephony” on this Swisscom website:

[https://www.swisscom.ch/de/about/unternehmen/portraet/netz/all-ip/alpen-und-ip-telefonie.html](https://www.swisscom.ch/de/about/ company/portraet/netz/all-ip/alpen-und-ip-telefonie.html)

and in the Swisscom leaflet:

[https://www.swisscom.ch/content/dam/swisscom/de/about/unternehmen/portraet/netz/all-ip/publikationen/downloads/grundbedarf-an-abgelegenen-standorten.pdf.res/grundbedarf-an -remote-locations.pdf] (https://www.swisscom.ch/content/dam/swisscom/de/about/unternehmen/portraet/netz/all-ip/publikationen/downloads/grundbedarf-an-abgelegenen-standorten.pdf.res/grundbedarf-an -remote-locations.pdf)

Technical details can be found in the SAB report:

[http://www.sab.ch/fileadmin/user\_upload/customers/sab/Press Releases/2020/Final Report_Conversion_to_IP_Final.pdf](http://www.sab.ch/fileadmin/ user_upload/customers/sab/Press Releases/2020/Final Report_Umstellung_auf_IP_Final.pdf)

in the magazine “Schweizer Landtechnik” from March 2015 on page 18.

https://issuu.com/svlt-aseta/docs/lt_03_2015?e=1078673/57844620

and here:

[/t5/Archive-Internet/FritzBox-behind-4G-Router-DHCP-von-FritzBox-m%C3%B6glich/td-p/278783](https://commu nity.swisscom.ch/t5/Archiv-Internet/FritzBox-hinter-4G-Router-DHCP-von-FritzBox-m%C3%B6glich/td-p/278783)

Show original language (German)

@trendbook wrote:

Thank you very much Walter. I know the map. That’s why I know that there is actually no reception at that point according to this map.

I have my stance on these mobile network coverage maps at:

[/t5/Mobile/2G-shutdown-2020-new-white-spots-no-reception/m-p/617829#M7421](https://commu nity.swisscom.ch/t5/Mobile/2G-Abschaltung-2020-neue-weisse-Flecken-kein-Empfang/m-p/617829#M7421)

described.

Measure cell phone reception with a cell phone with “Network Monitor” (also note page 2!):
[/t5/Mobile/Natel-Empfang-bricht-%C3%BCber-die-Staffelegg-immer-ab/td-p/525279](https://community.swisscom.ch/t5/Mobile/Natel-Empfang- breaks-%C3%BCber-die-Steffelleg-always-off/td-p/525279)

Everything else is reading coffee grounds!

Aids for signal measurements are the cell phone’s internal network monitor (Samsung smartphone: call the phone number *#0011#) or the Cellmapper app:

https://www.cellmapper.net/apps

The information about SINR can be found at:

https://www.cellmapper.net/First_Time_Startup

observe!

The information on Timing Advance (TA) can be found at:

https://community.swisscom.ch/t5/Mobile/5G-Standalone/m-p/802417#M13826

observe!

You can also use a dual SIM-capable mobile phone and the BAKOM radio transmitter card to find out where and which mobile phone provider (Swisscom, Sunrise, Salt) operates its mobile phone antennas. Another mobile phone provider may be better positioned with its mobile phone antenna and offer a stronger mobile signal at the alpine hut!

[https://community.swisscom.ch/t5/Mobile/Mit-welcher-Handy-Antenne-bin-ich-verbunden/m-p/646543](https://community.swisscom.ch/t5/Mobile/Mit- which-cell-phone-antenna-am-I-connected/m-p/646543)

[https://community.swisscom.ch/t5/Mobile/Mobilfunkmasten-karte-nach-provider/m-p/813826#M14495](https://community.swisscom.ch/t5/Mobile/Mobilfunkmasten-karte-nach- Provider/m-p/813826#M14495)

The “Electric field strength” map is also helpful for finding Swisscom mobile phone antennas. See:

[https://community.swisscom.ch/t5/Mobile/Mobilfunkantenne-Eigent%C3%BCmer/m-p/799020#M13653](https://community.swisscom.ch/t5/Mobile/Mobilfunkantenne-Eigent%C3% BCmer/m-p/799020#M13653)

For voice telephony in the 4G/LTE and 5G mobile network, the measured value “RSRP” should be ≥ -90 dBm and the RSRQ value ≥ -11 dB.

https://arimas.com/2016/04/24/164-rsrq-to-sinr/

[https://www.lancom-forum.de/fragen-zu-lancom-umts-lte-router-f33/1780ew-4g-besser-durchsatz-t17549.html](https://www.lancom-forum. de/questions-about-lancom-umts-lte-router-f33/1780ew-4g-bad-throughput-t17549.html)

https://www.lte-provider.info/technik/rsrp.php

https://www.lte-provider.info/technik/rsrq.php

Another way to assess the 4G/LTE mobile signal received in the downlink is with the SNR value (more precisely: SINR). For voice telephony in the 4G/LTE and 5G mobile network, the measured value “SINR” should be ≥ 12 dB. For fast data transfers (Internet connection) the measured value “SINR” ≥ must be 12 dB.

[https://de.wikipedia.org/wiki/Reichweit\_(radio technology)](https://de.wikipedia.org/wiki/Reichweit_(radio technology))

https://arimas.com/2016/04/24/164-rsrq-to-sinr/

https://www.lte-provider.info/technik/sinr.php

Personally, I prefer to assess the cellular connection via the transmission power in the uplink. Thanks to the automatic, adaptive transmission power control (TPC), the transmission power in the uplink is reduced if the cell phone signal sent by the cell phone is received by the cell phone provider’s cell phone antenna with sufficient strength.

https://de.wikipedia.org/wiki/Uplink

https://de.wikipedia.org/wiki/Transmitter_Power_Control

The current transmission power in the uplink can be read out with the Network Monitor (value: TXPower, TXLevel or similar). When using not-too-long antenna cables between the mobile device and the external mobile phone antenna, the critical path is the uplink. The range of a mobile network is limited by the uplink. The range of the downlink is usually significantly greater thanks to the higher possible transmission power of the mobile phone antenna.
/t5/Mobile/Willkommen-in-Frankreich/m-p/616797#M7382

If the transmission power is limited in the uplink (thanks to TPC), it is very likely that the mobile phone will simultaneously receive a sufficiently strong mobile signal in the downlink (=> a sufficiently high SNR/SINR value). In this case, the mobile phone provider’s mobile antenna can reduce the transmission power in the downlink to the required minimum (=> lower radiation exposure thanks to TPC).

The rule of thumb for reliable terrestrial radio connections (without line of sight between the transmitting and receiving antenna; with multipath reception), such as mobile communications, is a transmission power reserve of 25 dB. 25 dB means that the radio signal received by the receiver is received 316 times stronger than would actually be minimally required. A detailed explanation of why a transmission power reserve of 25 dB (Rayleight fading) should be aimed for in mobile communications can be found at:

[https://community.sunrise.ch/d/26711-feedback-zur-netzcover-an-eine-specific-ort/8](https://community.sunrise.ch/d/26711-feedback-zur- network coverage-at-a-specific-location/8)

https://de.wikipedia.org/wiki/Reichweit_%28Funktechnik%29

https://en.wikipedia.org/wiki/Rayleigh_fading

According to 3GPP TS 36.101, Chapter “6.2 - Transmit Power”, the maximum permissible transmission power for mobile devices in the frequency band 20 (800 MHz) is 200 mW (23 dBm). The desired transmission power reserve of 25 dB is achieved with a transmission power of -2 dBm (10 µW).

If there is a line of sight between the transmitting and receiving antennas, the required transmitting power reserve must be calculated using the Rice fading channel model. See:

https://de.wikipedia.org/wiki/Reichweit_%28Funktechnik%29

[https://www.gaussianwaves.com/2020/08/rician-flat-fading-channel-simulation/](https://www.gaussianwaves.com/2020/08/rician-flat-fading-channel-simulation /)

https://nbviewer.org/github/kirlf/CSP/blob/master/MIMO/RicianFlatFadingMATLAB.ipynb

https://www.lntwww.de/Mobile_kommunikation/nichtFrequenselektives_Fading_mit_Direktkomponent

Salt has already stopped broadcasting the 2G/GSM mobile radio signal, Swisscom will follow suit by switching off 2G/GSM at the end of 2020. And Sunrise probably knows which end customers are allowed to use the Sunrise 2G/GSM mobile phone network, over what period of time and with what network coverage not exactly myself…

[https://www.sunrise.ch/de/business/produkte-und-loesungen/connectivity/2G-weiterhin-nutzen-sunrise.html](https://www.sunrise.ch/de/business/produkte- und-loesungen/connectivity/2G-weiterhin-nutzen-sunrise.html)

[https://mobilecommunity.ch/wbb/index.php?thread/370-salt-gsm-abschaltung/&postID=2931#post2931](https://mobilecommunity.ch/wbb/index.php?thread/370- salt gsm shutdown/&postID=2931#post2931)

[https://mobilecommunity.ch/wbb/index.php?thread/370-salt-gsm-abschaltung/&postID=3006#post3006](https://mobilecommunity.ch/wbb/index.php?thread/370- salt gsm shutdown/&postID=3006#post3006)

[https://www.heise.de/news/GSM-Mobilfunk-Die-Schweiz-schaltung-ab-5000513.html](https://www.heise.de/news/GSM-Mobilfunk-Die-Schweiz- switches-off-5000513.html)

I expect all Swiss 3G/UMTS mobile networks to be switched off between 2025 and 2030.

https://de.wikipedia.org/wiki/Mobilfunkfrequencies_in_der_Switzerland

An official statement from Swisscom on the shutdown date of the 3G/UMTS mobile network (UMTS900 => 3G/UMTS on mobile frequency band 8 => 900 MHz) can be found at:

[https://community.swisscom.ch/t5/telefonie-Wissensbox/2025-ist-Schluss-3G-macht-Platz-f%C3%BCr-mehr-leistung/tac-p/703050] (https://community.swisscom.ch/t5/telefonie-Wissensbox/2025-ist-Schluss-3G-macht-Platz-f%C3%BCr-mehr-leistung/tac-p/703050)

Therefore, new mobile communications solutions for voice telephony that are VoLTE-compatible should be implemented in 2020.

[/t5/Mobile/2G-Abschaltung-2020-neue-weisse-Flecken-no-Empfang/m-p/618372](https://community.swisscom.ch/t5/Mobile/2G-Abschaltung-2020-neue-weisse -Stains-no-reception/m-p/618372)

Show original language (German)
3 months later

Hello.

Yes, in the meantime I have installed an official analogue Swisscom satellite Anschluss with Swisscom. But thank you for the info, I will keep the product in mind for other inquiries.

Show original language (German)
a year later

Hello,

I happened to read this article while looking for information about VoLTE.

I researched AVM routers (FritzBox!) and VoLTE

Their 5G router (6890) is backwards compatible - but does NOT support VoLTE.

A few days ago I read at AVM that a laboratory firmware was offered for the FritzBox 8650.

This laboratory firmware enables telephony via the mobile phone number.

Just saying….. in case anyone is interested….

Btw. Brack currently has the best offer for the 6850

Show original language (German)

Caution!!!!!!!!!!!

I posted the wrong link earlier/just now!!

The previous one was for the 6890 LTE!

This is NOT possible with the 6890 LTE!

Here’s the right one:

[https://avm.de/fileadmin/user\_upload/DE/Labor/Download/fritzbox-6850\_lte-labor-96343.zip](https://avm.de/fileadmin/user_upload/DE/Labor/ Download/fritzbox-6850_lte-labor-96343.zip)

To read:

[https://avm.de/fritz-labor/frisch-aus-der-entwicklung/neues-und-besseren/einfacher-telefonieren-mit-fritzbox-6850-direkt-ueber-die-mobilrufnummer-ihrer-sim-karte -call/] (https://avm.de/fritz-labor/frisch-aus-der-entwicklung/neues-und-besseren/einfacher-telefonieren-mit-fritzbox-6850-direkt-ueber-die-mobilrufnummer-ihrer-sim-karte -call/)

Please check whether the 6850 LTE has the latest firmware!

Only then play the laboratory.

Btw: You can always reset using recovery

Here you go 🙂

Show original language (German)

I just ordered a 6850 LTE.

I wanted to make the second router unnecessary.

Because I want to turn off my cell phone after work, I have the following constellation:

An older Fritzbox 6840 LTE as a modem

Behind it is a 7490 - it has a 3G modem in it:

Huawei E-173 - bought from Swisscom at the time.

However, NOT all E-173s were CSV capable.

It doesn’t say that anywhere. - can only be found out by looking at the firmware.

Now I wanted to make the 7490 unnecessary.

When I’ve installed everything, I’ll report back 🙂

Show original language (German)
7 months later

Installed it a week ago - worked for a week!

Now I suddenly can’t call German numbers.

Swiss mobile numbers work.

Swiss landline numbers only partially!

Swisscom? NO support! - no supported device!

AVM? - so far no result.

They say that it CANNOT be due to the Fritzbox 6850 LTE,

because it can make calls, receive and sometimes send with the laboratory FW.

Well - if that’s true…

Now I’m in a quandary…

I was so happy that the telephony worked via VoLTE…

Show original language (German)

@Fuchspassauf wrote:

Now I suddenly can’t call German numbers.

Swiss mobile numbers work.

Swiss landline numbers only partially!

Sounds like there is a configuration issue or a firmware issue with the country code or area code. And in the laboratory, AVM of course tests with the country code for Germany…

For outgoing telephone calls, is the telephone number to be called always dialed with +41 or +49?

When using VoIP-capable telephones that are connected via an Ethernet network cable, the SIP data traffic must be monitored for troubleshooting and evaluated with Wireshark. Eavesdropping is difficult to implement on all other telephone connections.

Show original language (German)