Handover 3g – 2g 850 – 1900

Hi,

Can you help me please, we have NSN network with 850 an 1900MHZ, and also 2g network with 850 and 1900. The recommendation of NSN, is that there should only be adjw between 2g (850-1900) and 3g (850), 3g(1900) only receives the handover from 850 3g.

I think there should be all the adjacencies between both technologies (2g-3g) and interfrecuency 2g (850 -1900 ) vs 3g (2g -3g)

What do you people think?

Thanks