Tinted glass can have a definite affect on cell phone signals.
Propagation of Radio Waves (802.11)
Properties of media
The weakening of signal strength is largely due to the properties of the medium that the wave is passing through. Here is a table showing attenuation levels for different materials:
MaterialsDegree of attenuationExamples
AirNoneOpen space, inner courtyard
WoodLowDoor, floor, partition
PlasticLowPartition
GlassLowUntinted windows
Tinted glassMediumTinted windows
WaterMediumAquarium, fountain
Living creaturesMediumCrowds, animals, people, plants
BricksMediumWalls
PlasterMediumPartitions
CeramicHigh Tiles
PaperHigh Rolls of paper
Concrete High Load-bearing walls, floors, pillars
Bulletproof glassHigh Bulletproof windows
MetalVery high Reinforced concrete, mirrors, metal cabinet, elevator cage