Design of partially survivable networks for cellular telecommunication systems

In cellular networks, cells are connected to the mobile telephone switching office (MTSO) directly or via hubs. It may also be desirable for some cells to split their traffic to two or more hubs for partial survivability in the case of equipment failures; such cells are said to have diversity requirement greater than one. Assuming that hubs are connected to the MTSO via self-healing rings, as is common in current cellular implementations, the objective is to find the assignment of cells to hubs – including the MTSO – that meets demand as well as survivability requirements at minimum cost. With the increasing use of fiber for high capacity backbone transmission, networks have become sparser, and the consequences of link failures much more serious. Hence network survivability has taken on added urgency. Our paper models this problem in the context of cellular networks.