In the scenario of 802.11n 2.4GHz routers, and assuming a very simplified example of only channels 6 and 11:
- Us in Building A: router on channel 6
— next door —
- Building B: router on channel 6
— far away —
- Building C: router on channel 11
For best performance for us working in Building A,
will the routers share the channel 6 frequency proactively, and therefore less likely to have collisions,
OR
Is it better to pick channel 11 as the router using that is far away and less likely to interfere?
Essentially do wireless routers engage in a primitive form of TDMA (time-division multiple access) or similar?
Best Answer
If those are your only two choices, building A should be on 11 for best performance. Access points use CSMA/CA, not TDMA. The CA stands for collision avoidance, so they listen first before transmitting. If they hear someone else talking (over a certain threshold), they will wait until the channel is clear before transmitting.
If you use Ch 11, then you will not have any channel contention, since the other AP signal (bldg C) will be very low (I am assuming no other APs than what you've described).
If you put bldg A on channel 6, then it will compete with bldg B for channel time, reducing throughput for both buildings. If the signal from the adjacent building is low enough, it won't cause channel contention, but it can still lower your SNR (signal to noise ratio) and lower your throughput due to errors and retransmissions.