|LANCOM Systems Support KnowledgeBase - Support Information|
Document No: 1404.1610.5851.RHOO
The IEEE 802.11 standard contains virtually no criteria by which a WLAN client should select the access point for a connection. While there are, for example, general guidelines for the preference given to an access point with a higher RSSI value (i.e. the received signal strength), WLAN clients do not, in practice, adhere strictly to these definitions or the general guidelines. If both 2.4GHz and 5GHz are used to broadcast an SSID, there is normally no way of influencing the client as regards the preferred frequency band.
There are several, sometimes highly advanced, criteria for steering. One of these criteria relates to the wireless frequency ranges used for client communication. Modern dual-band WLAN clients are expected to prefer the 5GHz frequency band over the (now) overcrowded 2.4GHz band. Band Steering is the term given to purposefully assigning a WLAN client to a particular frequency band or range.
This document describes how WLAN Band Steering operates and how you set up the feature in the configurations of LANCOM access points.
WLAN Band Steering is a component of the LANCOM Active Radio Control (ARC) .
In LANconfig you can use Configuration -> Wireless LAN -> Band Steering to enable and manage the LANCOM access point's Band Steering feature.
How WLAN Band Steering works:
For the process of WLAN Band Steering, the LANCOM access point maintains a list of all WLAN clients that it can "see" after receiving a probe request from each of them. In combination with the radio frequency on which the WLAN client sends the probe request, this list is one of the bases used by the access point to decide whether or not to respond to the request.
If a WLAN client has too low a transmit strength when SSIDs are reported, the WLAN client may not receive any probe responses at all on the preferred frequency band. In this case, it is important to ensure that the access point does not suppress probe responses on the less favored frequency band.
This is controlled by the minimal client signal strength setting to be found in LANconfig in the menu Configuration -> Wireless LAN -> General -> Logical WLAN settings -> Network -> Minimal client signal strength.
With a value set for the minimal client signal strength, the effect is as follows:
This value is specified as a percentage. This specifies the ratio of the signal and noise levels (SNR). A percentage value of 100% infers an SNR of 64 dB, smaller percentage values are correspondingly lower. The default value is 0 and with this value, no WLAN clients are ignored.