He directs research in mobile computing, is a pioneer in the area of location privacy and recognized for his work on connected vehicles.

Beyond these topics, his more than hundred peer-reviewed articles and patents span a wide range of wireless, mobile systems, and pervasive computing issues. He has served as program co-chair or vice-chair for conferences such as ACM MobiSys, ACM WiSec, IEEE VNC and IEEE Percom. He has delivered nine conference and workshop keynotes, served as panel moderator at ACM MobiCom, and as panelist at ACM MobiSys, IEEE Infocom, and IEEE ICC. He was elected treasurer and member of the executive committee of ACM SIGMOBILE.