Multi-Layer Design of IP over WDM Backbone Networks: Impact on Cost and Survivability

To address the reliability challenges due to failures and planned outages, Internet Service Providers (ISPs) typically use two backbone routers at each central office to which access routers connected in a dual-homed configuration. At the IP layer, redundant backbone routers and redundant transport equipment to interconnect them are deployed, providing reliability through node and path diversity. However, adding such redundant resources increases the overall cost of the network. Hence, a fundamental redesign of the backbone network avoiding such redundant resources, by leveraging the capabilities of an agile optical transport network, is highly desired. In this paper, we propose such a fundamental redesign of IP backbones. Our alternative design uses only a single router at each office but uses the agile optical transport layer to carry traffic to remote Backbone Routers (BRs) in order to survive failures or outages of the single local BR. Optimal mapping of local Access Routers (ARs) to remote BRs is determined by solving an Integer Linear Program (ILP). We describe how our proposed design can be realized using current optical transport technology. We evaluate network designs for cost and performability, the latter being a metric combining performance and availability. We show significant reduction in cost for approximately the same level of reliability as current designs

Joint Access-Backhaul Perspective on Mobility Management in 5G Networks

The ongoing efforts in the research development and standardization of 5G, by both industry and academia, have resulted in the identification of enablers (Software Defined Networks, Network Function Virtualization, Distributed Mobility Management, etc.) and critical areas (Mobility management, Interference management, Joint access-backhaul mechanisms, etc.) that will help achieve the 5G objectives. During these efforts, it has also been identified that the 5G networks due to their high degree of heterogeneity, high QoS demand and the inevitable density (both in terms of access points and users), will need to have efficient joint backhaul and access mechanisms as well as enhanced mobility management mechanisms in order to be effective, efficient and ubiquitous. Therefore, in this paper we first provide a discussion on the evolution of the backhaul scenario, and the necessity for joint access and backhaul optimization. Subsequently, and since mobility management mechanisms can entail the availability, reliability and heterogeneity of the future backhaul/fronthaul networks as parameters in determining the most optimal solution for a given context, a study with regards to the effect of future backhaul/fronthaul scenarios on the design and implementation of mobility management solutions in 5G networks has been performed.Comment: IEEE Conference on Standards for Communications & Networking, September 2017, Helsinki, Finlan