First of all, signal strength (RSRP=-98) is not great.
Next: B12 is 700MHz and at this frequency SXT as antenna has quite bad gain (negative). Gain in B2 (1900MHz) is a tad better, but that frequency suffers from higher free-air loss so net effect is probably the same.
Third: cell capacity is not great: 25MHz bandwidth (both bands combined) with CAT6 modem means up to 175Mbps for all active client devices combined. But that’s in perfect radio conditions which you’re not. (Perfect radio conditions would be RSRP greater than -70dBm and RSRQ greater than say -5dB).
Fourth: CA does not guarantee higher throughput … if the secondary bands (in your case B12) are highly utilized (e.g. because there are many users close to cell tower and they use lots of resources in that cell), then they easily don’t contribute much. Specially if radio conditions are not good (and secondary channels usually have worse radio signal than primar one).
If I assume some cell load (say 5 users active at the same time, all in mediocre to bad radio conditions - allowing something like 100Mbps of realistic cell capacity) I’d say what you get is decent.
the radio is NOT in the final installed location. Currently on a shelf in my office. I had no references
for signal strength. So will mount it on my mast later this afternoon.
Appreciate the info on the values, as now know what to look for.
I bought one of this for my dad, who plans to put it on a 80 foot tower. What is the reasonable range
on the SXT’s with free-air ? He’s about 8 miles from the nearest cell.
Low frequency bands (such as B2) without any obstacles in Fresnel Zone will reach much farther than 8mi. However this much depends on cell tower antenna placement (azimuth, tilt), usually these are high-gain antennae which means that signal out of main direction drops quite much (e.g. with 60° HBW antenna signal measured in direction say 40° from antenna direction can be 20dB lower than in main direction). Performance drops if there are obstacles blocking considerable part of Fresnel zone and plummets if more than half of Fresnel zone is blocked (i.e. in non-line of sight case).
Placing client device antenna on high mast helps a lot of course. The idea is to have LOS between SXT and cell tower antenna.
Throughput is always affected by interference (it mostly comes from adjacent towers, operating at the same frequency). As long as RSRP is good, the effect of interference is not too big. However, when signal drops below some decent threshold (say around -95dBm give or take), interference can become a big issue. Using directional antenna and adjusting azimuth helps with that. When mounting SXT, try turning antenna around to get highest RSRP with decently high RSRQ (RSRQ is in reality upwards limited to something like -2dB, anything higher than -5dB is good, higher than -8dB or something is decent). If you get comparable RSRP from two directions, choose direction with better RSRQ.
Max cell throughput for CAT6 terminal (modem) can be calculated as follows:
throughput = 150Mbps / 20MHz * frequency bandwidth
E.g.: cell operating on B2 with 10MHz bandwidth will be able to offer max 75Mbps. Obtainable throughput almost linearly drops with RSRP between -70dBm and -90dBm from 100% to something like 30% (e.g. terminal receiving said cell at -90dBm will be able to pull something like 25Mbps give or take). With signal further dropping towards -110dBm realistic throughput drops again, this time the relation may not be linear, depending on cell Tx power (if Tx power is high, then downlink might still work, but uplink becomes problem), also interference becomes more of an issue.
Higher categories of terminals (given support from network) rises max throughput to 200Mbps per 20MHz bandwidth (due to use of 256QAM modulation), but that only works in ideal radio conditions. Higher rank of MIMO (e.g. 4x4, comes in higher Cat terminals) rises the max throughput again, but that is mostly limited to high-frequency bands (i.e. above 2.4GHz), it’s impractical to build low-frequency cells for higher MIMO rank due to physical size of cell tower antennae.
You should do a Cell Monitor to check what your SXR detect the other sector antennas at the same Tower & other Towers antennas…
You should LOCK connection to B2 = earfcn:1125 with his antenna at tower: 101 by comman
/interface lte at-chat lte1 input=“atcell=2,3,1125,101" ;
what can be reverted/reset by
/interface lte at-chat lte1 input="atcell=0” ;
This do Cell Lock for stay connected with better band.
Remember that LTE Cat.6 device is DL+DL but UL is only from primary band and by locking primary band you are safe that upload will be dependence from one band.
Sunday they are standing up the 80ft tower, going to put the SXT on a rotor since there are
several cell towers in the 8-9 mile range, according to cellmapper.