Exactly, and this is
can be compounded on a new installation as you might be seeing noise or could
it be you are just misaligned?
Techs are creatures
of habit. They may think 4 LED bars is all that is ever needed because
thats what they typically see. The next install they throw up a radio
and get their usual 4 LED bars and dont realize 5 or more is
obtainable. Then a rainstorm comes in along with a 20F drop in
temperature and the link goes to crap because in fact they aligned the radio
on a side lobe.
Brad
-----Original
Message-----
From:
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gino A.
Villarini
Sent: Sunday,
September 24, 2006 11:48 AM
To: 'WISPA General List'
Subject: RE: [WISPA] vendor
specs
The
problem with SNR for alignment purposes is that you are dealing with a
variable in noise, with rssi you work with fixed numbers. Im not
dissing SNR, it is extremely important, But for example, in order to trouble
shoot a link
let say I install a Link and Im seeing a a SNR of 6 on this
link,how the heck can I determine if the antenna is miss aligned or the noise
floor is very high ???
Gino A.
Villarini
[EMAIL PROTECTED]
Aeronet Wireless
Broadband Corp.
tel
787.273.4143 fax 787.273.4145
From:
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Patrick Leary
Sent: Sunday, September 24, 2006 12:24
PM
To: WISPA General
List
Subject: RE: [WISPA]
vendor specs
Right, but the LED bar on the CPE can be
used to do that. I mean, isn't SNR more complete than just RSSI, meaning if
your SNR is good than the RSSI is by default good. Anyway, I have never heard
of any moderately experienced VL user say the units did not convey enough info
to easily establish a link and understand the quality of the connection.
Consider that with the CPE VL radio the LEDs will show:
WLAN link light-
·
Solid Green Unit is associated with an AU, no
wireless link activity
·
Blinking Green Data received or transmitted on
the wireless link, blinking rate is proportional to wireless
traffic rate
·
Off Wireless link is disabled
Status light
·
Solid Green Power is available and self-test
passed
·
Blinking Amber Testing (not ready for
operation)
·
Red Self-test failed fatal error
Ethernet light
·
Solid Green Ethernet link between the indoor and
outdoor units is detected, no activity
·
Blinking Green Ethernet connectivity is OK, with
traffic on the port. Blinking rate proportional to traffic rate
·
Red No Ethernet connectivity between the indoor
and outdoor units
SNR bar
·
Red LED: Signal is too low (SNR<4 dB)
·
Orange LED: Signal is too high (SNR > 50
dB)
·
8 green LEDs: Quality of the received signal
(green LEDs translate per below)
LED 1 (red) is On - Signal is too low
(SNR < 4 dB)
LED 2 (green) is On - SNR > 4
dB
LEDs 2 to 3 (green) are On - SNR > 8
dB
LEDs 2 to 4 (green) are On - SNR > 13
dB
LEDs 2 to 5 (green) are On - SNR > 19
dB
LEDs 2 to 6 (green) are On - SNR > 26
dB
LEDs 2 to 7 (green) are On - SNR > 31
dB
LEDs 2 to 8 (green) are On - SNR > 38
dB
LEDs 2 to 9 (green) are On - SNR > 44
dB
LEDs 2 to 9 (green) and 10 (orange) are
On Signal is too high (SNR > 50 dB)
Mod level : Sensitivity : Min. SNR (this
chart for 20MHz channel)
1 : -89 dBm : 6 dB
2 : -88 dBm : 7 dB
3 : -86 dBm : 9 dB
4 : -84 dBm : 11 dB
5 : -81 dBm : 14 dB
6 : -77 dBm : 18 dB
7 : -73 dBm : 22 dB
8 : -71 dBm : 23 dB
Patrick Leary
AVP WISP Markets
Alvarion, Inc.
o: 650.314.2628
c: 760.580.0080
Vonage: 650.641.1243
-----Original Message-----
From:
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of G.
villarini
Sent: Sunday, September 24, 2006 8:48 AM
To:
wireless@wispa.org
Subject: RE: [WISPA] vendor specs
Patrick,
Rssi is very important to determine if a
link is properly aligned and its achieving its link budget.
Altough we dont use alvarion(yet), we
are currently researching backhaul options and the way we comission ptp links
here is that we run the calcs on radio mobile and spreedsheet to determine the
link budget in advance to implementation. Snr wont help much
there...
Gino
-----Original
Message-----
From: "Patrick
Leary"<[EMAIL PROTECTED]>
Sent: 9/24/06 11:32:47
AM
To: "WISPA General
List"<wireless@wispa.org>
Subject: RE: [WISPA]
vendor specs
Brad,
Software controlled
dual polarity might be nice. Not sure why you
consistently harp on
us though since no one else has it either other
than your longtime
preferred vendor.
I am not as convinced
about your complaint about RSSI. Is it just used
to RSSI like being
used to feet in stead of meters. But also, isn't RSSI
less sophisticated and
a less useful number than SNR since it is only an
indication of receive
signal without discounting noise? SNR provides a
more accurate
representation of wanted signal since it discounts for
unwanted
noise.
Not sure of your
complaint about the RJ45. No one else remarks about it
and we don't have
issues with water intrusion. In other words, it works
well. If the opening
was enlarged you increase the potential for water
intrusion.
Following the color
code? Yes, as an old cabling guy, I would agree. But
I am pleased to note
that one is really running out of things to harp
about when one
continually highlights this a major deficiency.
So now that I have
responded here to your public mail, will you please
admit that even if the
VL came to life and saved your kid from a flood
you complain that it
was not fast enough and that it ripped the kid's
clothes. I wish some
day you'd accept that your customer chose VL and
you should take the
opportunity to learn about it instead of still
trying to make it fail
so you can get them to switch to Trango. Even the
best radios will have
room for improvement and every decent brand should
have something special
that differentiates it. You work so hard to find
fault you miss
opportunities to become proficient in more than one
brand. So accept our
invitations to allow engineer visits and accept our
invitations to be
trained. Know what I mean?
Patrick
Leary
AVP WISP
Markets
Alvarion,
Inc.
o:
650.314.2628
c:
760.580.0080
Vonage:
650.641.1243
************************************************************************************
This footnote confirms
that this email message has been scanned by
PineApp Mail-SeCure
for the presence of malicious code, vandals & computer
viruses.
************************************************************************************
--
WISPA Wireless List:
wireless@wispa.org
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives:
http://lists.wispa.org/pipermail/wireless/
--
WISPA Wireless List:
wireless@wispa.org
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives:
http://lists.wispa.org/pipermail/wireless/
************************************************************************************
This footnote confirms that this email
message has been scanned by
PineApp Mail-SeCure for the presence of
malicious code, vandals & computer viruses(191).
************************************************************************************
************************************************************************************
This footnote confirms that this email
message has been scanned by
PineApp Mail-SeCure for the presence of
malicious code, vandals & computer viruses(43).
************************************************************************************