Free Speak-II: Does FS-II create any interference with a DAS system?

A customer has an AT&T DAS system (Distributed Antenna System) and wants to install a 1.9GHz FS-II system, but is concerned about any interference created by the FS-II or received from the DAS system since AT&T also operates in the 1.9GHz range.


AT&T uses the PCS-1900 band in the US for LTE they use frequency block 2

Uplink =              1850.2 – 1909.8

Downlink =         1930.2 – 1989.8

 Transmission power is up to 5 watts

 FSII uses DECT frequencies with a maximum of 250 milliwatt transmission power

 1,928,448 - 1,921,536

 1,928,448           1,926,720           1,924,992           1,923,264           1,921,536

The FS-II system is in the 1.9 GHz range, but we use different frequencies within this band, in addition we have guard band filters to avoid bleed over into adjacent frequencies.

On top of that, we transmit at such low power we cannot affect ATT. It’s the other way around. They can affect us, but they also have guard band filters, so this is not going to be a problem coexisting in this facility.