AP7562i count of radios issue

[Aviv_Kedem]

Hello community,

I have AP7562i is 3x3 with 3 RF connectors: R1-A,R1-B, R1-C.
When disconnecting the antenna from R1-A connector, but R1-B & R1-C still connected to their connectors - the transmit power is dropped to near 0.
It seems R1-B & R1-C RF connectors are not transmitting at all.

CLI output:

show ver
AP7562 version 5.9.2.5-001R
Copyright (c) 2004-2018 Extreme Networks, Inc. All rights reserved.
Booted from primary

ap7562-xxxxxx uptime is 0 days, 00 hours 03 minutes
CPU is ARMv7, No. of CPUs 2
Base ethernet MAC address is xxxxxxxxxxxxxx
System serial number is xxxxxxxxxxxxxx
Model number is AP-7562-670042-xx

ap7562-xxxxxx#show wi ra de

Radio: 74-67-F7-xx-xx-xx:R1, alias ap7562-xxxxxx:R1
STATE : On
PHY INFO : Bssid: 74-67-F7-xx-xx-xx RF-Mode: 2.4GHz-wlan
ACCESS POINT : Name: ap7562-xxxxxx Location: default Placement: Outdoor
CHANNEL : Current: 1 Configured: smt Width: 20MHz
TRANSMIT POWER : 20 dBm
ANTENNA USAGE : 3x3
MAXIMUM DATA RATES : Phy: 288 Mbps User: 216 Mbps
PHY SETTINGS : Short Preamble: N Dual Channel: N Spectrum Mgmt: N
RATE SELECTION : Standard
ANTENNA DOWNTILT : Not-Supported
RADIO SHARE MODE : Off
TRANSMIT BEAMFORMING : Enabled
MU-MIMO : Not-Supported
SCAN_AHEAD CHANNEL : -
ERP COEXISTENCE : ERP Protection: N Non-ERP detected: N Non-ERP associated: N
HT COEXISTENCE : HT Protection: nonmember mode, Non-HT detected: Y
Current Channel Width: 20Mhz, reason: per configuration
Num of Mcast Streams : 0 (max:25)
Multicast streams :
# MP Mcast Streams : 0
WLAN MAP :
BSS-1 : test123* (*=primary)
Shutdown WLANs :
MESHPOINT map :
BSS MAP :
BSS-1 : basic-rates = 1 2 5.5 11
: supported-rates= 1 2 5.5 6 9 11 12 18 24 36 48 54 mcs-1s mcs-2s mcs-3s
Last error :

Any ideas?

Thanks,

Aviv Kedem

[vanelm]

Hello Aviv,
Even if we manage to send unicast frames to clients in isolated freezer with antenna B or C. Beacons and broadcast will _always_ sent from antenna A.
As I said, AP is designed to use all antennas simultaneously - it is how 802.11 works.

Misha

[Aviv_Kedem]

Hello Миша,

The goal in this case is to split the wireless coverage of the AP for 2 small frigidaired rooms.
So tested with "antenna-diversity" but without any change on AP7562, but with AP6532 "antenna-diversity" is working well.
Tried with 2x2 mode - with no change.
Tried configure with TKIP only mode + "antenna-diversity" to do it work in legacy mode - no change.

Any suggestion for suitable configuration in this case?

Thanks a lot!

Aviv K

[vanelm]

Hello Aviv,

- AP7562i as it certified for IL comes with facade antenna which is perfectly tuned. Replacing integrated antenna is a regulatory violation. But who cares.
- 802.11n and 802.11ac utilize all available antennas while listening. Every additional antenna provides roughly 2dBm on RX. This is calls MRC (Maximal Radio Combining) and considered as a main benefit coming with 11n.
- Replacing factory antennas with a "better ones" will bring you improvement not because you will send a better signal at a maximum power but because better antennas will provide a better gain on listening the clients.
- Sending "better" signal to the air will create additional co-channel interference which kill the service
- As others said, management traffic is always sent as a single stream with single antenna (normally A). As well as to legacy clients and single stream clients.
- 802.11n and 802.11ac access point is designed to use all antennas in a same RF environment simultaneously. I.e. any client should create a signal on all antennas - than MRC will work.
- In case the "design" presume to use antennas in separated RF environments (like in a different freezers) than disabling MRC with "antenna-diversity" will solve the issue. Although dramatically decrease performance
- "no dynamic-chain-selection" will require 802.3at power and did not bring any feasible benefits

Misha

[Aviv_Kedem]

Hello Chris,

I trying to split the wireless coverage of the AP for 2 small frigidaired rooms.
antenna-mode 2x2 Not changed anything for me.Thanks,

Aviv K