Multiple Gazell networks in close proximety

[Rick.Soza]

We are using Gazell to stream data at <=6mS intervals for very low latency wireless gaming peripherals. We'd like to have many of these peripherals devices (more than 24) located in the same proximate area, each talking back to a different central gazell host.

Was curious what issues we'd run into, if each "Device to Host" network had the same channel tables (or very similar), but different base addresses. Can base addresses alone be used to identify a unique gazell network, and not run into collision issues from neighboring gazell networks?

If not, what is a better addressing and channel scheme to have many gazell devices streaming at maximum capacity?

[ovrebekk]

Hi

Unique base addresses is sufficient to identify the various Gazell networks, and avoid 'cross talk', but it is not sufficient to avoid packet collisions. If you have two different packets sent at the same time on the same RF channel you will most likely lose one or both of the packets.

Ideally then you would want as few Gazell networks as possible using the same RF channel.

The simplest way to do this is probably to randomize the channel tables for each network during the initial pairing phase (assuming you have one). You don't mention which chips you are using, but both the nRF24LE1 and nRF51x22 devices have a true random generator that can be used for this purpose.

Depending on the number of channels in the channel table you don't want to make the channel selection completely random, as it is recommended to spread the channels over the entire 2.4GHz band to make sure they can't all be blocked by just one WiFi network.

If several Gazell networks share a single channel in their table with each other it should not be a big issue, as each network will stick to a channel where they experience little interference.

Regards Torbjørn