Multi-carrier access dynamically selects a preferred cellular carrier, by leveraging the availability and diversity of multiple carrier networks at a location. It o ers an alternative solution to the dominant single-carrier practice, and shows early signs of success through the operational Project Fi by Google. In this paper, we study an important, yet largely unexplored problem of inter-carrier switch for multi-carrier access. We show that policy con icts may arise between the inter- and intra-carrier levels, resulting in oscillations among carriers in the worst case, akin to BGP looping. We derive the conditions under which such oscillations occur for three categories of popular policy, and validate them with Project Fi whenever possible. We provide practical guidelines that ensure loop-freedom and assess them via trace-driven emulations.
|Resolving Policy Conflicts in Multi-Carrier Cellular Access ACM MobiCom'18|
Zengwen Yuan*, Qianru Li*, Yuanjie Li, Songwu Lu, Chunyi Peng, George Varghese
We gratefully acknowledge research support from NSF (CNS-1526985, CNS-1526456, CNS- 1423576, CNS-1421440, CNS-1749049, CNS-1750953, and CNS-1719403.) and the generous departmental support from UCLA and Purdue University.