30/11/2022, 12:50 AM
I did some further testing with a borrowed GoMo SIM (Eir network) which has band 28 coverage on the same >50km distant mast I pick up Three from. Unlike Three, Eir has recently become a right pain for trying to use cell locking to a band 20 or 28 cell when a band 1 or 3 cell is present. It kept trying to transfer my modem to band 1 or 3 as the primary band causing the connection to cycle up/down in a loop due to the distance. This showed up in the log as repeat "NW Detach" events:
The only way I managed to eventually get it to settle was to turn the dish antenna away such that bands 1 and 3 became very weak (around -120dBm). After a minute the connection finally settled on band 28 and was able to turn the antenna back towards the mast, where it then aggregated band 1 or 3 instead of trying to switch to it as the primary band. Disconnecting (e.g. reboot) would cause the issue to return until I turned the dish temporarily away again, so this rules out ever using that mast for Eir here.
This modem uses the same cell lock AT command as the EG12 and RG502 modems:
The upload speed is roughly the same as what I get on band 20 with Three from that distant mast with this setup. It was also interesting to see what download speed I could get with band 1 from Eir here as Eir requires an RSRP of -103dB or better on band 1 to aggregate it. The Iskra antennas with past testing could only achieve an RSRP of around -107dBm on band 1 with Eir, resulting in the network not aggregating band 1.
Band 3 performs better on Eir, again requiring turning the antenna away until the cell stopped trying to hand over to band 3 as the primary band.
The only way I managed to eventually get it to settle was to turn the dish antenna away such that bands 1 and 3 became very weak (around -120dBm). After a minute the connection finally settled on band 28 and was able to turn the antenna back towards the mast, where it then aggregated band 1 or 3 instead of trying to switch to it as the primary band. Disconnecting (e.g. reboot) would cause the issue to return until I turned the dish temporarily away again, so this rules out ever using that mast for Eir here.
This modem uses the same cell lock AT command as the EG12 and RG502 modems:
The upload speed is roughly the same as what I get on band 20 with Three from that distant mast with this setup. It was also interesting to see what download speed I could get with band 1 from Eir here as Eir requires an RSRP of -103dB or better on band 1 to aggregate it. The Iskra antennas with past testing could only achieve an RSRP of around -107dBm on band 1 with Eir, resulting in the network not aggregating band 1.
Band 3 performs better on Eir, again requiring turning the antenna away until the cell stopped trying to hand over to band 3 as the primary band.