XBee (series 1) miss reading outdoor

I set up a star network with 36 nodes in API 2 mode.

It worked good indoors (no miss reading), however it missed most readings outdoors.

It seems EVERY XBee can only listen to its neighbours within 2-3 meters in this outdoor network.

Who know what is this problem? Cheers.

Who know what is this problem?

We don't know what kind of XBees you are using (specifically what kind of antenna), what the environment is like, how the XBees are configured, how often they are sending data, or how much data they are sending. So, there is no way to guess what the problem is.

Networks are generally created using Series 2 models, since that is what they are designed for.