Thank you.
Performance is not the issue here. The issue is predicted signal
strength vs measured signal strength. The link works and works well.
Thruput and latency are well within expected ranges. I am just getting
numbers that don't make sense. Like the high power SR5 cards having a
lower output that the low power CM9 cards.....
Before I proceed with my planned deployment, I want to understand my
test readings.
Julius Igugu wrote:
Upgrade to 2.9.12. It has better wireless performance. Chech the
mikrotik forums.
----- Original Message ----- From: "Blair Davis" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Thursday, February 09, 2006 8:07 PM
Subject: [WISPA] MikroTik 5.8GHz Radio cards and settings.
Hey all:
I'm getting some odd results here with a PtP 5.8GHz link using
MikroTik that I setup to test with. Let me describe the setup...
The link is 7.9 miles with clear LoS and clear Frenel zone. Each end
has a 27db grid with a 3ft LMR-400 jumper to the MikroTik radio.
Using the link calculator at
http://www.zytrax.com/tech/wireless/calc.htm I get a predicted rx of
-60.8db at each end with CM9 radio cards (17db output). Using the
SR5 cards, (400mW), I get a predicted rx of -51.8
On to the real world results.... (all reading taken from the
MikroTik's winbox. I am using version 2.9.11 on RouterBoard 230's)
With the CM9 cards, I get a measured rx of -62db, well within the
margin of error. An interesting note here is that I must set the
CM9's output power in the MikroTik at 30db to get these results.. I
know that the MikroTik must be doing something odd with this setting,
as the CM9 can not put out 30db. Reducing the setting drops the rx
strenth by a like amount. This link is stable and will pass 30Mb/sec
in UDP and 22Mb/sec in TCP mode
With the SR5 cards, I get a measured rx of -66db, well outside the
margin of error and 15db below the expected rx strength! An
interesting note here is that I must set the SR5's output power in
the MikroTik at 30db to get these results. I know that the MikroTik
must be doing something odd with this setting, as the SR5 should not
put out 30db. Reducing the setting drops the rx strength by a like
amount. This link is stable and will pass 24Mb/sec in UDP and
16Mb/sec in TCP mode.
Nothing else is changed when I swap the SR5's for the CM9's or back
again. I use the same antennas, cables, boards and pigtails. The
antennas and cables are not moved between tests. (except for moving
the pigtail from one card to the other).
Can anyone tell me what I am doing wrong here? Or do I just have
some bad SR5 cards? Or is the tx power setting in the MikroTik
flakey? Or is the tx power setting relative db not absolute db?
BTW, I will be changing one end to a sector and wish to use the SR5
cards then. Otherwise I'd be happy with the -62 on the CM9's
Thanks in advance.
--
Blair Davis
AOL IM Screen Name -- Theory240
West Michigan Wireless ISP
269-686-8648
A division of:
Camp Communication Services, INC
--
WISPA Wireless List: [email protected]
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives: http://lists.wispa.org/pipermail/wireless/
--
Blair Davis
AOL IM Screen Name -- Theory240
West Michigan Wireless ISP
269-686-8648
A division of:
Camp Communication Services, INC
--
WISPA Wireless List: [email protected]
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives: http://lists.wispa.org/pipermail/wireless/
