Hi Colin
I greatly appreciate your reply.
I should have made myself more clear on the voice picking terminals. These terminals are not actually true voice over wifi. They are really text-to-speech over wifi.
Basically The Warehouse Management System sends data to the terminal that is displayed on the screen but also translated into speech -that is heard through a headset that is attached to the terminal.
The user then uses phrases and commands (that each user has to train when initially getting setup for use) that are then sent back to the Warehouse Management System. When there are problems with the connection to this system, the user will hear a number of beeps that are then followed by a comms error on screen. This then causes the user to get kicked out of their picking task, This causes alot of frustration for the guys as they are paid on a performance based pay scheme, therefore these interruptions/disconnects are affecting their pay packet.
The forklift terminals are bit more simple. Basically they logon to a Telnet session either using 'RFTerm' (on the Honeywelll Thor VM1 units) or with TelnetCE (on the IND3475). Alot of the time, the screens they are in can lag or else they can be completely kicked out/disconnected from their telnet session. The forklift driver then has to contact the WMS System Admin to kill their session so that they can login again and continue their work.
Just a note:
Warehouse 1 - is the only place where we use the Forklift Terminals
Warehouse 2 - is the only place where we use the "Text-to-speech"/Voice Picker Terminals
- What kind of access points do you have deployed?
Warehouse 1
A mixture of IAP304 (with directional antenna - AP-ANT-38) and IAP305 (omni). There is an IAP304 mounted on every aisle in the Warehouse - these are staggered so that they are at opposite ends every aisle (x22). The IAP305s are mounted in the middle of every other aisle (x11).
Warehouse 2
A mixture of IAP304 (with directional antenna - AP-ANT-38) and IAP305 (omni). There is an IAP304 mounted on every aisle in the Warehouse - these are staggered so that they are at opposite ends every aisle (x9). There are x2 IAP305s in the middle of the warehouse although we currently have these set to spectrum monitor mode.
Note: There are sections in this Warehouse/Cluster, dry goods and the freezer. I've only given you the AP numbers and information for the dry goods area as this is the area I have been focusing my testing and troubleshooting in.
- How high are they mounted?
Warehouse 1
IAP304 - at one end 6m high at the other end approx. 4m high
IAP305 x11 - approx. 50ft/15m high
Warehouse 2
IAP304 - x5 at one end approx. 3.4m high. x4 at opposite end approx. 5m high
- How far apart are they mounted?
Warehouse 1
IAP304 - approx. 12m apart
IAP305 - approx. 12m apart
Warehouse 2
IAP304 - approx 12m apart
IAP305 - approx. 18m apart
- How many SSIDs do you have deployed?#
Warehouse 1
1 x SSID in Cluster
Warehouse 2
1 x SSID in Cluster
- Do you have individual clients running on both bands? (Is the voice picker configured to operate on both the 2.4ghz and the 5ghz band)?
Warehouse 1
No, currently we are running the Forklift Terminals on 2.4ghz band only - 802.11g. I have actually tried running these on 5ghz band - 802.11a - but we just have the same issues.
Warehouse 2
No, the "Text -to-speech"/Voice Picker Terminals are all running on 5ghz band - 802.11a.
- Are your drivers up to date on your scanners and voice pickers? Many of those devices were not deployed initially on 802.11ac access points and updated drivers allow better interoperability.
Yes, we have updated the drivers of the client devices to the latest possible versions.
- Do you have any non-default settings on your SSIDs? (I see you cut of the lower transmit rates...why?)
The lower rates were trimmed I believe to promote better roaming. This was done by TAC when we had contacted them during our initial setup phase of Warehouse 1. We then carried this on when we setup Warehouse 2.
As regards non-default settings - the following were also set:
Broadcast filtering to All
Multicast transmission optimization to Enabled
Dynamic multicast optimization to Enabled
DMO channel utilization threshold 90%
802.11r, 802.11k & 802.11v are all unticked.
- If you disable scanning, APs will not be able to scan other channels to mitigate interference. Turning off scanning is typically a troubleshooting step to make the environment more stable, if the access points have already chosen optimal channels.
Scanning is off in Warehouse 1. But on in Warehouse 2. This hasn't made a difference either way.
- Client Match depends on scanning to find clients that are nearby, but not on their same channels. You should be able to operate your network without client match, in principle.
On another note in Warehouse 2 we have completely locked down (admin assigned) channels and power on APs (All APs are either channels 36 , 40, 44 or 48 - non-DFS channels and are either set to 15dbm or 18dbm). When ARM was enabled we thought it might be making too many changes making the RF environment unstable - I admit this is a longshot, but I would try anything to stop these disconnects.
I can upload maps if this helps at all.
Thanks