Why do I need to use a SAW filter in my design?
In several regions, upload in the LTE band occurs at frequencies located closer than 10 MHz from frequencies used by Z-Wave. Due to the high power level allowed, in addition to the loose restrictions on side band emissions granted to the LTE band, the LTE upload may interfere significantly with the operation of a listening Z-Wave node located nearby.
To reduce the impact from other devices, the Z-wave device must incorporate a SAW filter which attenuates these technologies, thus preventing saturation of the receiver.
The effects of interference from LTE is outlined in LTE Case Study.