There can be several different types of wireless challenges, especially in environments/areas such as warehouses/production facilities etc.
Most often, a non-uniform device type is used, e.g. scanners from different manufacturers (intermec, symbol etc.) and these can then have different supplicants installed to take care of the network connection. It is more the rule than the exception that these are not centrally managed/configured, so you usually see different devices with different network setups. Drivers and supplicant versions are usually not maintained and can vary a lot in relation to which wireless setup will be optimal for your particular setup. The areas that should be looked into in order to have a good wireless environment are reviewed below.

• RF environment
  • Does the device support the configured channels
    • On 2.4GHz, it has been seen that devices do not support channel 13 (Because this is not found in e.g. regulatory Domain A). However, channel 13 is rarely used.
    • Does the device support the UNII channels that are configured. Examples have been seen of devices not having support for e.g. UNII-2/UNII-3 channels.
    • Due to the often challenging placement of APs, it may be necessary to activate lower data rates than usual. In some cases, it may be necessary to enable 802.11b to support certain devices. Most of the time, high throughput is not required and a low data rate that gives a larger coverage area will usually be preferable.
    • It is often necessary to use external antennas with extra amplification and directional ones, which can mean that you usually have to lock the output power and/or channel.
    • It is my experience that you are often forced to create specific RF profiles for warehouses/halls. Partly due to various AP/antenna types and their location and partly to accommodate various devices that often support different technology. Typically, there is a need for lower data rates than in office environments as well as a narrowing of channels and at the same time it may be necessary to set a min. power output so as not to “lose” coverage in outer areas. It is also necessary in some cases to determine channels manually if there are strong inner walls where devices traverse.

Always use Separate RF profiles in every challenging location

• Roaming
  o Longer roaming time for high 5GHz channels
  • Some NIC manufacturers scan higher 5GHz channels less often than the low 5GHz rates. This can cause the device not to roam before it releases the AP it is associated with, which will cause a greater or lesser interruption when roaming.

Be care of using FT / adaptiv FT and PMF. Have seen many devices that not support these settings

• Roaming technologies
  • 802.11k
    • A standard that, when the client supports this, helps to optimize roaming using information that the client builds up around the surrounding APs.
  • 802.11r
    • This is also called FT (Fast Transition) and optimizes the authentication process when roaming. Can be implemented as:
      • Adaptive Supports both devices with and without 802.11r
      • Enable Devices must support 802.11r
      • None 802.11r is not supported. Works for all devices.
  • 802.11v
    • Optimizes roaming by selecting the AP that is best suited to handle the device. It also has other features such as multicast optimization.
  • CCX/Aironet extension
    • This is an older Cisco proprietary standard that has some of the same features as 802.11k. A number of older devices support this and can advantageously make use of this.
• Authentication
  • On devices in the mentioned environments there may be advantages/disadvantages depending on which authentication is used. Most often, when you don’t have managed devices, PSK is used, if necessary, together with an iPSK solution on ex. ISE. For PSK solutions, the key is located on the individual APs, which results in minimal roaming times. If dot1.x authentication is used where a radius server must be involved, it is recommended to use FlexConnect groups/Site tags, which reduce the need for radius communication.
• Devices
  • On Scanners etc., a supplicant (e.g. FUNK) is often used to control the network card. This applies especially if Win CE is used. If using Win10 or Windows’ own network management is usually used. Common to these is that the setup is made in accordance with the wireless network. Of the set-up that should be looked into are, among other things, the following:
    • Roaming aggressiveness (most often, with advantage, can be set to high… but takes more battery)
    • Channel selection (If possible, only look for channels the wireless network uses, so that the device does not spend time scanning channels where it cannot be connected anyway). Also applies if scanning is to be done on both 2.4GHz and 5GHz.
    • CCX should be enabled if it is enabled on the wireless network (aironet extension)