I have an LTAP Mini and a mANT omni directional antenna. My installation is stationary for now. Right now, the router and the antenna are on the side of a tree, near the ground. I have run both of them way up into the tree, 90 feet or so, and not seen an appreciable difference in signal.
From a user experience perspective, things seem barely fine until the evenings when I assume the towers get totally clobbered… the signal doesn’t seem to change but my speeds sure do.
1 - Given these numbers, is there any way I can predict what kind of improvement might be possible with a higher gain / more directional antenna? Can I subtract the 5 dBi rating of the mANT antenna from my current signal, and then add the dBi rating of an antenna I’m interested in to try to predict my upgraded signal strength?
2 - Can I just connect one antenna? Under what conditions do I need two antennas / both antenna connectors in use.
Antennas are expensive… the mANT just barely gets me online. I don’t want to waste more money!
Signal strength (RSRP) you’re getting is, as chart indicates, poor. And with poor signal you can’t get decent throughputs. GSMA has a document about LTE network performance which includes indicative table on pages 15-16. Don’t choke on band (1800MHz) mentioned, LTE performance is almost same on every frequency band. If frequency channel used is narrower than 20MHz, then performance decreases almost linearly.
Using better antenna directly improves performance. Just take antenna gain (note that antenna gain varies with frequency and you have to consider gain for frequency band your device actually uses), add currently measured RSRP and substract gain of currently used antenna. E.g. if you get antenna with gain of 10 dBi and current setup gets RSRP at - 112dBm while currently used antena gain is 2 dBi, you will get (10+(-112)-2)=-104dBm. Table in linked document indicates that you’d double throughput you’re getting.
Another fact: signal doesn’t pass through tree tops easily. So you may actually get better results if you mounted LTE antenna low (e.g. 5-10 ft above ground) but away from trees. Try to get clear line of sight between your LTE antenna and cell tower, specially in vicinity of your antenna.
Thanks! It sounds like maybe my understandings aren’t too far off.
The antenna situation is a real bummer. It looks like the higher gain antennas don’t generally hit band 12 very well… A common Wilson yagi has just 7.3 dB gain in band 12 freqs, but 10.6 at higher frequencies. That’s just not gonna make much of a difference. Though… Mikrotik wasn’t able to provide me any frequency response specs for the mANT antenna, so maybe its gain is much lower than I think.
Which particular mANT antenna are you using? But it is true that wide-band antenae generally have smaller gain in low frequencies than in higher frequencies[*] … I’ve seen Mikrotik directional antenna with nominal gain of around 5dBi but had negative gain at 700MHz (also band 12) that they didn’t really advertise. That’s why it is important to consider antenna gain for the frequency actually used and I’d stay away from antenna vendor who doesn’t provide decent gain charts (both frequency domain as well as spatial charts). For example LTE antenna by Iskra, they provide technical catalogue with decent information for all of their products.
[*] It’s all about size. Antenna elements must have dimensions proportional to wavelength and 700MHz antenna with similar performance as 3.5GHz antenna has to be 5-times larger in all dimensions. With small multi-band antennae this simply isn’t possible because vendors tend to use whole available volume for high-band portion which makes low-band portion physically of same size, hence performance of such antenna sucks in low band.
Just as illustration: professional antenna for low band (e.g. 15dBi gain, 10° vertical beam height, 60° horizontal beam width) used in comercial LTE networks, has dimensions around 1’x0.5’x10’ (WxDxH). If high-band antenna is done with same physical dimensions (i.e. combined antenna), the high-band part will have 3-5dBi higher gain (and only 4-5° vertical beam height).
I have the mANT LTE 5o and L-COM HG72710XP-065. The difference is 10 ~ 12 dBm of RSRP (-103 to -93) (Both tested on indoors, not outdoors). The main difference was the upload speed in my case. The tower that I’m connect, is very good.