Using DFS for userfiles between 2 locations that are in the same Site

We have dfs installed on ServerA and ServerB.
Both servers are Windows Server 2008 R2 running DFS 2008.
Replication is being done on user home folders.
ServerA and ServerB are in the same Site – but they are at different locations that are connected wirelessly.
When a user logs on to a workstation that is at the same location as ServerA – we want ServerA to be the ActiveSite.
When a user logs on to a workstation that is at the same location as ServerB – we want ServerB to be the ActiveSite.

How can I accomplish this?