Problem to TX End device to Coordinator, and RANGE indoor

Hello, Im building a WSN for a domotic application, at this moment, im testing the Xbee ZB, im making a network with 1 coordinator and 2 end devices. My principal problem is that sometimes one of the ED doesnt TX the information to the coordinator and other times it does. All End Devices are connected to a pic microcontroler that indicates what is gonna be TX using the serial interface, and the Coordinator is pluuged to the PC using te XBEE Xplorer.

Another cuestion inside my apartment, the network doesnt form if the EDs are in another room (3 mtrs to the coordinator), only separated with the coordinator for 1 wall, according to the datashhet, the network should be form because for this devices the range is 40 mtrs indoor… anybody can explain this to me?

I hope if you are using PIC controller, then you can use Sleep Mode as ‘Cyclic Sleep Pin Wake’. So while sending data from PIC over the UART you can wake the XBee by Pin Wake technique.

If the Wall in between is the Cement Concrete Wall, or if other RF interference like florecent light etc are there, then the indore range can decrease. You need to calculate link budget for RF signals…

As you know, each wavelength can passthrough certain width of different materials. Therefore the RF link budget calculation you need to do.