Single-channel wifi design instead of standard multi-channel

Hi, I'm interesting in another wifi design than classic. Standard design with APs managed by WLC use different channels (e.g. for 2,4GHz ch.no. 1, 6 and 11) which alternates from one AP to the second. This design is very usefull, if wifi-clients don't move too much or too quickly. But if wifi client moves, especially if it moves rapidly, there are issues by roaming from one AP to second - many times reassociation takes too long time, or client keeps association with original AP up to very low signal and tries to reconnect too late (not from original AP to the nearest, but for a far AP).

I listen about another wifi design, when all managed APs are on the same channel and decision about association with AP is on WLC. I tried to find some documents about this on Zyxel, but unsuccessfully.

Does anybody know, how is single-channel design called by Zyxel and what WLC can support this? It is applicable on NXC5500? Or it depends on AP types too?

Kind regards

Jindrich

Answers

  • Good8WifiGood8Wifi Member, R Posts: 4  Freshman Member
    As far as I know, this wasn't supported by current Zyxel WLAN solution.
    The benefit of "Single channel" wifi is that all APs behave like one AP. So when client roam from one AP to the other, client doesn't need to roam. The benefit of single channel is obvious, while the disadvantages are probably also very obvious:
    1. capacity - while only one channel is used, comparing to utilize all the available spectrum, the capacity is much smaller.
    2. co-channel-interference - WLAN is CSMA/CA, to avoid collision, IEEE standard defines the CCA (clear channel assessment), even manipulate the threshold, it is unavoidable that  the collision will happen. (or to be more precisely, the co-channel-interference will impact the receive sensitivity and causing a lot of retries wasting air-time in the end).
    3. Limited scalability - Multiple APs to form a single AP, means several things. For example, APs have to take turns and send beacon one by one. This will very easily cause scalability problem and often interoperability problem.

    The 802.11K/V/R together has greatly improve the roaming capability and it will be only gets better. The single channel is to form a mega AP to eliminate the roaming. Which way to choose? I know with current zyxel solution, i can build a very robust wireless network for voice with any roaming problem.
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