Hi,

I'm evaluating the performance of routerOS on a RB912UAG-2HPnD board for use on an autonomous underground loader. They are intended to be a replacement for ACKSYS units that can do rapid roaming between Ubiquiti Bullet 2HP APs for the automation system with as little packet loss as possible. In the area that the machine travels in, there are multiple AP's with the same SSID and channel to roam to and signal levels rarely drop below -60dBm across the area, with two or three AP's being visible at any one time. Having all the APs on the same channel does make roaming easier for the station, and there is typically only the one station on each site as the area is restricted access when the machine is operating so there is little interference in practice.

With the latest software release, the units seem to roam reasonably well, however currently it seems that the units wait until almost complete loss of signal from an AP before seeking out and connecting to another AP. The resulting packet loss and lower modulation speeds before disconnect/reconnect tends to upset the automation system.

Ideally, I'd like to be able to set a minimum signal strength that, once reached, prompts the station to start looking for a new AP to connect to. For example, at -60dBm the station checks all the beacon packets of APs nearby and if there is one with a higher signal, it roams to it in an orderly manner. The signal strength from a single AP can go from marginal to very poor fairly quickly (in a couple of seconds) if the machine goes around a corner, so by being able to set a custom minimum strength to begin the roaming process I can avoid packet loss.

So...... is anything like this in the works? Seeing as both the ACKSYS and Bullet2HP units have both suddenly been discontinued, I'd like to try and stick with one manufacturer for everything on these sites.

I know this is an old thread, but if you are still looking for a solution, you may want to look for APs that support 802.11k (roaming/neighbor reports). (and maybe also 802.11r) . these protocols, if the AP and client support them, allow the AP to give the client a list of "offical similar" aps near by, for the client to very quickly roam to when needed (helps the client in that client does not need to keep doing background scans to find new APs to roam to).

Im pretty sure MT APs do not support 802.11k (i dont think MTs as clients do either, but you should prob test this). I dont think UBNT APs do either (they have their own form of "fast roaming" but i dont think its real 802.11k , and ive seen alot of bugs on their fourms on their implementation). I think ruckus APs support 11k/r, but *only* when APs are used with a ruk controller ( $$). (maybe check if MT APs mgmt'd by capsman support 11k ? i havent tested capsman much myself)

If you want to stick with all MT (aps and clients, bc of mt amazing features and functionality), on the station side, the mt manual states that if "Station roaming" is enabled, the AP will background scan for new APs to roam to MORE frequently if the current AP signal is lower, and less frequently if signal is higher. (in my limited tests/experience, mt to mt roaming does result in a few seconds of connectivity disruption though, but my tests where limited and a yr or so ago). On the MT AP side, you could try specifiying the AP's Clients minium signal in the APs connect-list (or maybe its in the access-list). what this will do on the AP side is, if a client signal drops below X signal, the AP will kick the client (thus forcing client to connect to a new AP).

If you really need seamless, un-interupted station roaming, you will just need to test (either MTs solution, or APs/clients that support 802.11k / r )