Hi all, just looking for opinions/thoughts on a 13km 4600c, both sides with 3ft dishes. I have excellent line of sight as per link planner, full 36dbm as per the AFC tool, I have used the rain prediction tool in LP as well. What are thoughts on this link in real world?
We use Force400c on a 15Km PTP link, with 3’ dish on Master side, and 2" dish on Slave side. I wish I had room for a 3’ dish on both sides – but even as it is, it works really really well. I realize my 400c is 5ghz but I’d expect the results would be similar and very very good.
I really appreciate the reply… the 13km link does not need to be crazy but as per link planner it should aggregate 900mbps using eptp on 160mhz channel. I am always hesitant with link planner to real time lol
Well, this was a test I did quite a while ago (Firmware 5.1 even!) with Force 400c at nearly 15km, and got 450mbit in 40Mhz channel in 5Ghz. This was running Mikrotik bandwidth test between two MT 4011’s on either side of the Force 400c, so this isn’t using the built in Cambium Link Test thing.
2 Likes
Is that tdd ptp or eptp?
This particular backhaul link is ePTP. Mostly all of my Force 300 Backhauls are TDD (75%/25%) because for us, 300’s ePTP falls apart when it’s at high usage, so TDD works better for us on Force 300s. BUT, for 1000/2000/4000 series and PTP links, ePTP usually gives us much better results without a fixed duty cycle, as long as it’s someplace where we can be in a flexible mode, and aren’t concerned about SYNCing with anything else.
That being said, probably longer term, we’re likely to go GPS Sync & Frequency use, and then of course that’d be TDD at that time.
Also to note again - this is a 400c so that’s 5Ghz, not a 6Ghz 4600. But I just wanted to help out and show what we’re getting with a ‘4000 series AX’ ePMP backhaul.
I appreciate that, it helps as I am troubleshooting 2 400c eptp links right now. one is on 5.9 and its link test is 350 DL and 100 UL and the modulation goes to shit, before 5.9 it was solid ds11 on both UL and DL. The other link is 5.6 and solid ds11 and 467DL and 424 UL.
Question for you, if I have 467 DL and 424 UL in eptp mode should tdd ptp be roughly 660 DL and 220 for UL?
ePTP mode is typically more efficient then TDD fixed or flexible mode. TDD flexible mode operates similar to ePTP mode in that each frame can be nearly 100% uplink or downlink, or a dynamic ratio of the two as conditions demand. Finally, speeds using TDD with a fixed duty cycle will typically be slightly lower then ePTP due to TDD overhead.
e.g. if you’re getting 500/500 in ePTP mode… then you’ll probably get around 325/125 in TDD-fixed mode with a 75/25 duty cycle. The only time you might see better aggregate speeds using TDD fixed mode is if there are collocation considerations that demand a fixed ratio and GPS sync in order to reduce interference.
No. ePTP and TDD Flexible Frame should give pretty much the full link capacity in either direction. So, if a link is capable of 460 mbit of total capacity, then Flexible Frame or ePTP (also Flexible) will give close to that capacity in either direction, based on the needs.
If you go to fixed frame TDD, that is you telling the radio to have a fixed duty cycle of 75% / 25% or of 66% / 30% or whatever you choose. So if your radio link is capable of 460 mb, and if you choose 66/33, then at maximum, you’ll get 66% of that 460 in download - and you’ll get act maximum 33% of that 460 and upload. In fixed frame, the point is to always spend the set percentages in the transmit mode, and in the received mode - even if there’s no data going in that direction.
So, TDD Fixed Frame will usually give you less throughput in either direction overall, but it is designed to give you more organized and therefore synchronizable use of your frequencies. If you want to reuse frequencies, the only way to do it would be to have all your AP and all your SM to be all synchronized so they are transmitting and receiving the same intervals, and it therefore (it still requires some planning and design) therefore possible to reduce self interference.
But flexible frame, and eptp mode, will be able to entirely fill the link up with 97% / 3% if that’s what the current bandwidth requirements are. So if your link is capable of 460 megabit, in theory you could get 440 in one direction, and 20 in the other… A little dynamically adjust on the fly, to try to maximize the throughput, based on which direction you’re pushing data at that instant. But the trade-off is no frequency reuse. There’s no way to have two radios that are arbitrarily TX and RX at any given time, and to try to synchronize and share channels. That’s the downside of flexible / eptp frames.
2 Likes
Hi, I was able to get 1300mbps via wireless test on my 10km link with eptp + low latency.
Setup
algcom uhpx 30db both ap and station
My best signal is -42 RSSI
Is that a 400c or 4600c? If it is a 400c, is it a 40 or 80mhz channel?
its 4600c at 160mhz on 27db power at 6370mhz, sorry forgot to provide more info
@DigitalMan2020
with 3ft dish, I think you’ll be able to meet DS MCS 13 if no EIRP limit
Hi @DigitalMan2020. I’m wondering if you have you tried the 5.9.1-RC yet?
One of the fixes listed is the following:
1 Like
Appreciate the feedback! Is that 1300mbps aggregate?
Thank you and sorry for late reply, I was able to implement the 5.9.1 RC and it is solid!
2 Likes
AWESOME to hear that!
1 Like