When my husband is far (in other country) are we allowed to talk about sex on telephone and as if we were in bed together?

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

As for your talking about sexual matters to arouse each other's sexual desire, this can have very bad consequences as it might lead you or him to searching for some place to satisfy that desire, hence committing Zina. So we advise both of you to be patient and occupy yourselves in what pleases Allah.
We advise your husband to do his best to bring you next to him or return home as soon as he can.

Allah knows best.