According to the documentation I can find, Cellular.RSSI().rssi values should be in the range of -113 to -51. I’m getting values in the range from 43 to 46. My .qual values are around 18 to 20, so within the documented range of 0 to 49.

Boron LTE or 3G/2G? The exact model will be useful :slight_smile:

Good point. It’s the Boron LTE

Not sure… but mine shows up fine! unsigned long old_time = 0; void loop() { if (millis() - old_time > 10000) { CellularSignal sig = Cellular.RSSI(); Particle.publish("CS", String(sig), PRIVATE); old_time = millis(); } }

What are some typical values that you get for the CS sig value?

I’m getting the same issues with odd signal values. I’m getting RSSI values around 30-40 (which isn’t in the documented -113dBm to -51dBm range), and quality of around 10 (which is a lot lower than a SIMComm module on the same antenna). It is running an external SIM from Telstra in Australia, and running rc.25. Cellular is working, as it’s the only connectivity the module has, but is having stability issues.

I have confirmed that we have an issue with Electron-compatible RSSI / quality calculation on Borons, which we’ll fix in the next release, however going forward we’ll be migrating to using the new (and currently undocumented) API that provides information on the current radio access technology (RAT) as well as RAT-specific strength/quality parameters along with percentages: https://github.com/particle-iot/firmware/blob/mesh-develop/wiring/inc/spark_wiring_cellular_printable.h#L48. I can suggest using it as a workaround on Borons to get more sensible strength and quality values for now. getAccessTechnology() returns one of the following values: NET_ACCESS_TECHNOLOGY_UNKNOWN = 0, NET_ACCESS_TECHNOLOGY_NONE = 0, NET_ACCESS_TECHNOLOGY_WIFI = 1, NET_ACCESS_TECHNOLOGY_GSM = 2, NET_ACCESS_TECHNOLOGY_EDGE = 3, NET_ACCESS_TECHNOLOGY_UMTS = 4,, NET_ACCESS_TECHNOLOGY_CDMA = 5, NET_ACCESS_TECHNOLOGY_LTE = 6, NET_ACCESS_TECHNOLOGY_IEEE802154 = 7 For each RAT getStrengthValue() and getQualityValue() return RAT-specific strength and quality parameters, whereas getStrength() and getQuality() will return the percentage based on minimum and maximum values (0% - 100%). GSM Strength: RSSI (dBm) [-111, -48], see 3GPP TS 45.008 8.1.4 Quality: BER (Bit Error Rate) (%) [0.14%, 18.10%], see 3GPP TS 45.008 8.2.4 EDGE Strength: RSSI (dBm) [-111, -48], see 3GPP TS 45.008 8.1.4 Quality: log10(Mean BEP) (Bit Error Probability) [-0.6, -3.6] (QPSK table), see 3GPP TS 45.008 10.2.3.3 UMTS (3G) Strength: RSCP (dBm) [-121, -25], see 3GPP TS 25.133 9.1.1.3 Quality: Ec/Io (dB) [-24.5, 0], see 3GPP TS 25.133 9.1.2.3 LTE Strength: RSRP (dBm) [-141, -44], see 3GPP TS 36.133 subclause 9.1.4 Quality: RSRQ (dB) [-19.5, -3], see 3GPP TS 36.133 subclause 9.1.7 (cc @rickkas7)

@avtolstoy, thanks for the note, but I’m not quite clear on what you mean by “use it as a workaround on Boron for now.” getAccessTechnology() is not defined on my Boron. Do mean that it should be available now automatically? Or available now if I do something special (like include a library)? Or is it something that is not yet available, but will be coming in the future? Thanks.

It should be available. It is a method of CellularSignal class. CellularSignal s = Cellular.RSSI(); auto rat = s.getAccessTechnology(); float strengthVal = s.getStrengthValue(); float strengthPercentage = s.getStrength(); float qualityVal = s.getQualityValue(); float qualityPercentage = s.getQuality();

@avtolstoy, While I value compatibility with the 2G devices, this is a significant improvement over what we had before. I have tested this approach in my own applications and am very happy with this change. I would only suggest updating the Bottom reference documentation to reflect this new approach. Thank you! Chip

Boron LTE and Cellular.RSSI() - funny values

Connectivity BLE // NFC

superseb December 18, 2018, 4:37am 7

Same issue for me on Boron LTE, I get 44 and 22 for both RSSI value as an example.

Boron LTE now support in Canada?

Topic		Replies	Views
Boron Cellular Signal General boron	7	1520	August 8, 2019
Calculation of cellular signal indicator in web interface Cloud boron , cellular	0	842	June 4, 2019
Cellular.RSSI() not working on E-Series Firmware	2	737	August 16, 2018
No signal strength information for Electron 2G on Device OS 1.0.0 Firmware electron	23	2054	October 1, 2019
Electron Cellular RSSI returns 0 Troubleshooting	3	985	February 27, 2018

Boron LTE and Cellular.RSSI() - funny values

Related topics