Spatial Grounding and mobile phones

I have read an interesting paper "Why people say where they are during mobile phone calls" form Eric Laurier (submitted to Environment and Planning D : Society and Space). The author presents the specific feature of mobile phone conversation : the giving of a geographical formulation as part of an opening of a phone call. Look Schlegoff (1972) who worked on the analyses of "locational formulations". Laurier's study deals with how space influence grounding in the context of nomadic workers. His methodology is quite odd ?????

How a spatio-temporal context is being mutually accomplished between the caller and the called. The answerer's locational formulation is setting up some kind of mutual sense of his/her context.

He examined two cases : - the caller asks "where are you ?" or the answerer says where he is before being asked. - the caller asks "where are you TODAY ?"

The problem of this paper is that the writer focuses on people who needs space for their jobs : space is embedded in the task. Hence it must be different for other users (hanging out youngsters for instance).