Hi all, have a force 25 and just want to share its stats to gain some insight on all the values.....
It is 12 km from the AP
RSSI downlink/uplink is -64/-60
SNR downlink/uplink 26/26
Downlink quality is 100% and downlink quantity is 75%
Downlink MCS stats.... 75% MCS 8 MCS 7 25%
Uplink MCS stats.... MCS 7 92%
My downlink quantity never goes above 75%... what should I do and where should I start investigating?
Thanks!!
For the RSSI and SNR, that looks about right. If you want to get to MCS 9, you will need to increase the RSSI at the SM. If you already have LOS to the tower, then there is not much more you can do, besides maybe using a 300 CSM with a 2ft dish. That will give you around a 3-4db increase in RSSI.
@CWB wrote:For the RSSI and SNR, that looks about right. If you want to get to MCS 9, you will need to increase the RSSI at the SM. If you already have LOS to the tower, then there is not much more you can do, besides maybe using a 300 CSM with a 2ft dish. That will give you around a 3-4db increase in RSSI.
Thank you for the reply! I will try a realignment at the SM side to be sure.... I was just curious if I was perhaps having a interference issue
@DigitalMan2020 wrote:RSSI downlink/uplink is -64/-60
You'll also want to keep particular attention to the chains too. A -64 signal seems good, BUT in a 2x2 scenario, that can be comprised of a -67 & -67 = -64 . . . but it can also be comprised of a -64 & -77 = -64 instead. That -77 chain will perform horribly, and will reduce capacity (and overall AP Sector capacity too)
Likewise, in a 4x4 scenario, it's even more critical. Thinking a -64 is a good signal... that's not necessarily true anymore in a 4x4 world. That -64 in 4x4 might comprised of a -69 & -71 & -70 & --69 chains added together to give that -64... Yet none of those chains are stellar and aren't really going to want to modulate at the maximum modulation. Plus that -64 might be a -67 & -81 & -68 & -77 too.
So, what we're trying to do is to achieve a -60 on each chain if possible (which often results in a -54 signal when all chains are added together), and to really try to make sure we have chains as balanced as possible - - which isn't easy with the Force300-25's mounting.
But, the worst chain is the key - - - a -60 & -76 signal will add together into a -59 and that signal might lookd good, but will perform poorly due to the wonky aiming/chain. :)
@ninedd wrote:
@DigitalMan2020 wrote:RSSI downlink/uplink is -64/-60
You'll also want to keep particular attention to the chains too. A -64 signal seems good, BUT in a 2x2 scenario, that can be comprised of a -67 & -67 = -64 . . . but it can also be comprised of a -64 & -77 = -64 instead. That -77 chain will perform horribly, and will reduce capacity (and overall AP Sector capacity too)
Likewise, in a 4x4 scenario, it's even more critical. Thinking a -64 is a good signal... that's not necessarily true anymore in a 4x4 world. That -64 in 4x4 might comprised of a -69 & -71 & -70 & --69 chains added together to give that -64... Yet none of those chains are stellar and aren't really going to want to modulate at the maximum modulation. Plus that -64 might be a -67 & -81 & -68 & -77 too.
So, what we're trying to do is to achieve a -60 on each chain if possible (which often results in a -54 signal when all chains are added together), and to really try to make sure we have chains as balanced as possible - - which isn't easy with the Force300-25's mounting.
But, your worst chain is the key - - - a -60 & -76 signal will add together into a -59 and will seem good, but will perform poorly. :)
Thank you for the awesome, informative reply ninedd! Vey helpful! Okay so my signal is a bit bouncy... at worst -64 at best -62, it flip flops between the two signals... so ch0 is at worst -67 and at best -66 and ch1 is at worst -65 and best -64. So what formula are you using for taking a -60 and -76 signal to add into a -59? Also for a good balance of chains is all in the alignment?,in which I believe you eluded to that I now know that Im not the only one that hates the 25s mounting bracket ;)
Also I just looked and the download capacity is now sitting at 90% instead of 75% as of earlier. One other thing to note is that on the sector perfomance stats the SM is showing 4.7% packet retransmission and on the SM itself it shows currently a 3% packet retransmission... probably some interference?
@DigitalMan2020 wrote:Okay so my signal is a bit bouncy... at worst -64 at best -62, it flip flops between the two signals... so ch0 is at worst -67 and at best -66 and ch1 is at worst -65 and best -64.
OK - so those are fairly well balanced. 2 db chain imbalance is decent. So, that's not your problem then. :) I had mentioned that as a potential problem, because I have seen times when people are looking at an overall -64 thinking that is a good signal, but hidden in the weeds is a horrible chain - but this is not the situation in your case. :)
>>So what formula are you using for taking a -60 and -76 signal to add into a -59?
Well, every 3db is double the signal. So, adding a -60 & a -60 is a -57. Likewise, going from a -65 to a -68 seems like not too much of a loss, but that 3db loss it's actualy 1/2 as loud.
So, I was just saying that it's not safe to simply look at a -59 and think it's all wonderful - if you've got a bad chain imbalance (which you don't have) and if that -59 is comprised of a -60 and a -76... that -76 is still as much of a problem as it was back in the single-polarity days. Again - you have about 2 dB chain difference, which is pretty decent. :)
>>Also for a good balance of chains is all in the alignment?
Well, that's the thing you can be careful about. Some people have reported a bad batch of F300's, but I'm not sure I've seen that problem with the stock we have. So you can have a chain imbalance for other reason, but for sure, aiming can be one of those chain-mismatch reasons.. and it's something we can be very careful of and do our best for.
>>I now know that Im not the only one that hates the 25s mounting bracket ;)
it's especially frustrating because the F200 dish/mount/bracket was really good. I don't understand why they couldn't have made the F300 feedhorn fit the existing F200 dishes. That would have been SO MUCH cheaper to just buy/ship feedhorns, and not 100's of boxes and essentially identical dishes to what we already had installed. Don't get me started...
Again, thank you for the replies and info! So as for bad batches of f300 25s... what are people reporting?
@DigitalMan2020 wrote:Again, thank you for the replies and info! So as for bad batches of f300 25s... what are people reporting?
A couple people reported that they had some F300's with chain inbalances. I haven't seen that in all the ones we have - and you don't have chain inbalances anyway. You are 1 or 2 db out between chains, which is excellent. :)
@ninedd wrote:
@DigitalMan2020 wrote:Again, thank you for the replies and info! So as for bad batches of f300 25s... what are people reporting?
A couple people reported that they had some F300's with chain inbalances. I haven't seen that in all the ones we have - and you don't have chain inbalances anyway. You are 1 or 2 db out between chains, which is excellent. :)
Oh I see, great! Again thank you for the info!
So I forgot to ask, if the chain is good, and I cant get uplink capacity beyond 75%, am I dealing with interference? I have another customer that is relatively the same distance from tower and pretty much the same LOS situation and they have a balanced chain, 99% uplink quality and 90% uplink quantity.