Cisco 1552EU-E 2.4 Ghz Weak Signal

radu.ioncu · ‎09-21-2013

Hi,

I have just installed a Cisco 1552EU-E outdoor access point with the standard antennas: AIR-ANT2480V-N and AIR-ANT5180V-N. The 5 Ghz signal is great and still strong (-65 dB) even 100 meters away, however the 2.4 Ghz signal is beyond weak - 4 meters from the AP and it is barely visible. The 2.4 Ghz network is enabled from the WLC and everything looks ok settings-wise. The AP is configured in Flexconnect local switching with a virtual WLC.

Has anyone encountered simmilar issues and found a solution or root cause?

Thanks!

Scott Fella · ‎09-21-2013

From the data sheet, the EU is a single band AP

AIR-CAP1552E-x-K9
802.11N Outdoor Mesh Access Point, Dual band Ext. Antenna

AIR-CAP1552EU-x-K9
802.11N Outdoor Mesh Access Point, Single Band Ext. Antenna

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-Scott
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Jacob Snyder · ‎09-21-2013

Scott, these are dual band APs. The U stands for uniband antennas. The 1552e has dual band antennas and the EU uses separate 2.4 and 5Ghz antennas on this model.

I would check the power level on the 2.4 radio. You might try manually setting it to power level 1.

Show also might post the results of
> show ap auto-rf 802.11b

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radu.ioncu · ‎09-21-2013

Hi,

I have deployed a second, identical 1552 for the same project and the signal is strong for both 2.4 Ghz and 5 Ghz.

I have conducted a site survey in the vicinity of the 'faulty' 1552, and within 3 meters of the AP the 5 Ghz signal was -39 dB and the 2.4 Ghz signal was -89 dB and flapping. The power level is maxed out (1). I have checked the antenna connections and they are OK. The funny thing is that when I first installed it I quickly tested the connection using my iPhone 5 and a MB Pro, both which connected in the 5 Ghz band and thought everything was OK. However, users with mobile devices without a 5 Ghz radio soon started to complain about poor / non-existent signal.

Do you think I might be dealing with a faulty 2.4 Ghz radio on the 1552?

The result is below of the command is below:

(Cisco Controller) >show ap auto-rf 802.11b xx

Number Of Slots.................................. 2

AP Name..........................................

MAC Address......................................

Slot ID........................................ 0

Radio Type..................................... RADIO_TYPE_80211b/g

Sub-band Type.................................. All

Noise Information

Noise Profile................................ PASSED

Channel 1.................................... -100 dBm

Channel 2.................................... -96 dBm

Channel 3.................................... -93 dBm

Channel 4.................................... -98 dBm

Channel 5.................................... -96 dBm

Channel 6.................................... -97 dBm

Channel 7.................................... -96 dBm

Channel 8.................................... -98 dBm

Channel 9.................................... -88 dBm

Channel 10................................... -89 dBm

Channel 11................................... -90 dBm

Channel 12................................... -91 dBm

Channel 13................................... -94 dBm

--More-- or (q)uit

Interference Information

Interference Profile......................... FAILED

Channel 1.................................... -88 dBm @ 16 % busy

Channel 2.................................... -85 dBm @ 19 % busy

Channel 3.................................... -87 dBm @ 3 % busy

Channel 4.................................... -90 dBm @ 13 % busy

Channel 5.................................... -88 dBm @ 2 % busy

Channel 6.................................... -92 dBm @ 21 % busy

Channel 7.................................... -128 dBm @ 0 % busy

Channel 8.................................... -86 dBm @ 8 % busy

Channel 9.................................... -84 dBm @ 21 % busy

Channel 10................................... -79 dBm @ 2 % busy

Channel 11................................... -83 dBm @ 10 % busy

Channel 12................................... -84 dBm @ 2 % busy

Channel 13................................... -91 dBm @ 4 % busy

Load Information

Load Profile................................. PASSED

Receive Utilization.......................... 0 %

Transmit Utilization......................... 2 %

Channel Utilization.......................... 57 %

Attached Clients............................. 0 clients

Coverage Information

Coverage Profile............................. PASSED

--More-- or (q)uit

Failed Clients............................... 0 clients

Client Signal Strengths

RSSI -100 dbm................................ 0 clients

RSSI -92 dbm................................ 0 clients

RSSI -84 dbm................................ 0 clients

RSSI -76 dbm................................ 0 clients

RSSI -68 dbm................................ 0 clients

RSSI -60 dbm................................ 0 clients

RSSI -52 dbm................................ 0 clients

Client Signal To Noise Ratios

SNR 0 dB.................................. 0 clients

SNR 5 dB.................................. 0 clients

SNR 10 dB.................................. 0 clients

SNR 15 dB.................................. 0 clients

SNR 20 dB.................................. 0 clients

SNR 25 dB.................................. 0 clients

SNR 30 dB.................................. 0 clients

SNR 35 dB.................................. 0 clients

SNR 40 dB.................................. 0 clients

SNR 45 dB.................................. 0 clients

Nearby APs

AP 00:24:14:31:d6:00 slot 0.................. -63 dBm on 1 (192.168.2.100)

AP b4:e9:b0:16:74:e0 slot 0.................. -53 dBm on 11 (192.168.2.100)

--More-- or (q)uit

Radar Information

Channel Assignment Information

Current Channel Average Energy............... unknown

Previous Channel Average Energy.............. unknown

Channel Change Count......................... 0

Last Channel Change Time..................... Sun Sep 22 03:43:30 2013

Recommended Best Channel..................... 1

RF Parameter Recommendations

Power Level.................................. 1

RTS/CTS Threshold............................ 2347

Fragmentation Threshold...................... 2346

Antenna Pattern.............................. 0

Persistent Interference Devices

Class Type Channel DC (%%) RSSI (dBm) Last Update Time

------------------------- ------- ------ ---------- ------------------------

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(Cisco Controller) >

Scott Fella · ‎09-21-2013

My bad... I don't know what I was thinking. Any who... The only other thing I would do is make sure that the antennas are indeed the correct one for the 2.4ghz radio. Do you have another 1552 and is that working or are you also seeing the same issue. Post your:

show advanced 802.11b txpower

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-Scott
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radu.ioncu · ‎09-21-2013

Hi Scott,

I have indeed deployed a second 1552 and the signal levels are as expected. The antennas are connected in the right ports, I could try swapping out the 2.4 Ghz antennas :-?

Thank you!

The output for the command is below:

(Cisco Controller) >show advanced 802.11b txpower

Leader Automatic Transmit Power Assignment

Transmit Power Assignment Mode................. OFF

Transmit Power Update Interval................. 600 seconds

Transmit Power Threshold....................... -70 dBm

Transmit Power Neighbor Count.................. 3 APs

Min Transmit Power............................. -10 dBm

Max Transmit Power............................. 30 dBm

Transmit Power Update Contribution............. SNI..

Transmit Power Assignment Leader............... Cisco_01:02:c5 (192.168.2.100)

Last Run....................................... 291 seconds ago

TPC Mode....................................... Version 1

TPCv2 Target RSSI.............................. -67 dBm

TPCv2 VoWLAN Guide RSSI........................ -67.0 dBm

TPCv2 SOP...................................... -85.0 dBm

TPCv2 Default Client Ant Gain.................. 0.0 dBi

TPCv2 Path Loss Decay Factor................... 3.6

TPCv2 Search Intensity......................... 10 Iterations

AP Name Channel TxPower Allowed Power Levels

--More-- or (q)uit

-------------------------------- ---------- ------------- ------------------------

AIR-CAP1552-BAD *1 1/5 (15 dBm) [15/12/9/6/3/0/0/0]

AIR-CAP1552-GOOD *11 *1/5 (15 dBm) [15/12/9/6/3/0/0/0]

(Cisco Controller) >

Scott Fella · ‎09-22-2013

I would try swaping the antennas just to test. From the output, the radio is set as 15dbm just like the one that is working fine. If you swap the antennas and you still have issues, then I would open up a TAC case and tell them what you did and what you have seen and they will probably RMA that 1552.

AIR-CAP1552-BAD *1 1/5 (15 dBm) [15/12/9/6/3/0/0/0]

Thanks,

Scott

Help out other by using the rating system and marking answered questions as "Answered"

-Scott
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wuliting · ‎02-26-2018

I have the ANT2480V work with the AP 1562E with a very weak signal too.

My ANT5180V working fine with good signal.

I had make the tx power to level one, and i set the extantenna gain to 16, because this antenna ANT2480V is 8dbi.

I connect it to port 3&4 while the 5G antenna at port 1 & 2.

Any idea what i could change or check for the weak signal?

thank you.