Revolutionary mobile technologies, such as high-speed packet access 3G (HSPA+) and LTE, have significantly increased mobile data rate over the radio link. While most of the world looks at this revolution as a blessing to their day-to-day life, a little-known fact is that these improvements over the radio access link results in demanding tremendous improvements in bandwidth on the backhaul network. Having said this, today’s Internet Service Providers (ISPs) and Mobile Network Operators (MNOs) are intemperately impacted as a result of this excessive smartphone usage. The operational costs (OPEX) associated with traditional backhaul methods are rising faster than the revenue generated by the new data services. Building a mobile backhaul network is very different from building a commercial data network. A mobile backhaul network requires (i) QoS-based traffic with strict requirements on delay and jitter (ii) high availability/reliability. While most ISPs and MNOs have promised advantages of redundancy and resilience to guarantee high availability, there is still the specter of failure in today’s networks. The problems of network failures in today’s networks can be quickly but clearly ascertained. The underlying observation is that ISPs and MNOs are still exposed to rapid fluctuations and/or unpredicted breakdowns in traffic; it goes without saying that even the largest operators can be affected. But what if, these operators could now put in place designs and mechanisms to improve network survivability to avoid such occurrences? What if mobile network operators can come up with low-cost backhaul solutions together with ensuring the required availability and reliability in the networks? With this problem statement in-hand, the overarching theme of this dissertation is within the following scopes: (i) to provide low-cost backhaul solutions; the motivation here being able to build networks without over-provisioning and then to bring-in new resources (link capacity/bandwidth) on occasions of unexpected traffic surges as well as on network failure conditions for particularly ensuring premium services (ii) to provide uninterrupted communications even at times of network failure conditions, but without redundancy. Here a slightly greater emphasis is laid on tackling the ‘last-mile’ link failures. The scope of this dissertation is therefore to propose, design and model novel network architectures for improving effective network survivability and network capacity, at the same time by eliminating network-wide redundancy, adopted within the context of mobile backhaul networks. Motivated by this, we study the problem of how to share the available resources of a backhaul network among its competitors, with whom a Service Level Agreement (SLA) has been concluded. Thus, we present a systematic study of our proposed solutions focusing on a variety of empirical resource sharing heuristics and optimization frameworks. With this background, our work extends towards a novel fault restoration framework which can cost-effectively provide protection and restoration for the operators, enabling them with a parameterized objective function to choose desired paths based on traffic patterns of their end-customers. We then illustrate the survivability of backhaul networks with reduced amount of physical redundancy, by effectively managing geographically distributed backhaul network equipments which belong to different MNOs using ‘logically-centralized’ physically-distributed controllers, while meeting strict constraints on network availability and reliability
Multi-operator greedy routing based on open routers