Because it locates cellular devices, assigns frequencies, transmits signals to the correct sites, the is probably the most important part of any cellular network.

Mobile switching station

The mobile switching station is the most important part of any cellular network. It is associated with communications functions such as call set-up, release, and routing, locating cellular devices, assigning frequencies and transmitting signals to the correct sites. It also provides useful information such as user registration required to support mobile service subscribers.

a community that experiences major changes undergoes progress

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.