CJ Cherryh’s long-running Foreigner series has a lot of interesting linguistics in it. One of her specialties is writing non-human species (or post-human, in the case of Cyteen) with an almost anthropological bent. Whenever people ask for “social-science fiction,” she’s the second person I recommend (Le Guin being first). These stories usually involve intercultural communication and its perils and pitfalls, which is one aspect of sociolinguistics. It covers a variety of areas and interactions, from things like international business relationships to domestic relations among families. Feminist linguistics is often part of this branch: studying the sociology around speech used by and about women and marginalized people.
In Foreigner, the breakdown of intercultural communication manifests itself in a war between the native atevi and the humans, who just don’t understand why the humanoid atevi don’t have the same feelings.