Hi Alls,
I have 5.7 BH 20 Mbps with reflector each side n connect two location (approx. 15 miles). If i switch to 10 Mbps, i can get throughput about ~5-6 Mbps, but when i switch to 20 Mbps, the throughput only ~1-2 Mbps, RSSI 975 Jitter about ~11. How can 20 Mbps can give result than lower 10 Mbps at same place, same direction, and same frequency?
regards,
mrdlnf
What is the received power level at 10 and 20? It is expected that the jitter will go higher when using the 20 Mbps setting, but I still think 11 is kind of high. Can you paste the exact numbers when set at 10, and when set at 20?
Also, be sure that BOTH ends of the link are set to the correct modulation type. I ran into an issue where I was performing a link test and was getting 100% downlink and only 50% uplink. I looked into it and the problem ended up being that I had the master set to 20 Mbps and the slave still set at 10 Mbps.
15 miles is really pushing it at the 2x signalling rate. with a jitter of 11 at 2x (or 20MBps) you have to set it down, it will be more reliable and consistent that way.
I don’t know what is the relation between BH and X2, but the main difference between 10mbps and 20mbps modulation, that 10mbps needs at least -86dB power level, while 20mbps needs -76 or -78dB!!!
so on a 15mile link, i think you have to have at least 60-65 dB power level for a solid link with high enough link margin.
The higher jitter can be normal, while 10mbps modulation 1-3 is allowed, with 20mbps <10 is normal.
I have the same problem - sometimes the powerlevel is reached -76dB so 20mbps modulation did not work well so i’m switched the modulation back to 10. It would be nice if the unit 'd automatically can fallback in case of counters reaching the treshold value.
Dear Alls,
Thanks for explanation, i will try to re-align my BHs.
reagrds,
mrdlnf
Just for the sake of knowing, is there a published or well-known distance limitation where the 20 Mbps signaling should not be attempted, or is the power level the suggested guideline?