Network planning and design

About: Network planning and design is a research topic. Over the lifetime, 12393 publications have been published within this topic receiving 229776 citations. The topic is also known as: network design.

Network planning tool

Abstract: A communications packet network is planned by the use of a planning tool. The tool comprises an input for inputting requirements of the network; and an input for determining factors which effect the passage of packet based data through the network. A modelling module determines the performance of the network based on the requirements and factors. The performance of model is compared with that of an objective comparison model. A feedback mechanism iteratively adjusts the input factors to improve the performance and maintain the network requirements. When the desired performance level is achieved, a plan of the network is output from the planning tool.

Robustness of interdependent networks: The case of communication networks and the power grid

Abstract: We study the robustness of interdependent networks, in which the state of one network depends on the state of the other network and vice versa. In particular, we focus on the interdependency between the power grid and communication networks, where the grid depends on communications for its control, and the communication network depends on the grid for power. A real-world example is the Italian blackout of 2003, when a small failure in the power grid cascaded between the two networks and led to a massive blackout. In this paper, we study the minimum number of node failures needed to cause total blackout (i.e., all nodes in both networks to fail). In the case of unidirectional interdependency between the networks we show that the problem is NP-hard, and develop heuristics to find a near-optimal solution. On the other hand, we show that in the case of bidirectional interdependency this problem can be solved in polynomial time. We believe that this new interdependency model gives rise to important, yet unexplored, robust network design problems for interdependent networked infrastructures.

Network Design with Fixed and Variable Cost Elements

Abstract: A route selection algorithm is presented far designing transportation networks. The algorithm balances fixed construction costs and variable user costs in a network having a fixed set of nodes and a known demand, for internode service. The problem solved is a special case of the fixed-cost, multicommodity transshipment problem in which each commodity has a single, unique source node. The route selection algorithm alternatively applies link elimination and link insertion criteria that converge to a local optimum. Upper and lower bounds on the fixed and variable portions of the globally optimum solution are determined and the sensitivity of the solution is estimated. Unique rules are formulated for identifying links that must or must not appear in the globally optimum solution. The solution procedure has been coded for a digital computer and demonstrated using a representation of Minneapolis-St. Paul having 68 nodes and 476 potential oneway links.

Energy-Efficient Virtual Base Station Formation in Optical-Access-Enabled Cloud-RAN

Abstract: In recent years, the increasing traffic demand in radio access networks (RANs) has led to considerable growth in the number of base stations (BSs), posing a serious scalability issue, including the energy consumption of BSs. Optical-access-enabled Cloud-RAN (CRAN) has been recently proposed as a next-generation access network. In CRAN, the digital unit (DU) of a conventional cell site is separated from the radio unit (RU) and moved to the “cloud” (DU cloud) for centralized signal processing and management. Each DU/RU pair exchanges bandwidth-intensive digitized baseband signals through an optical access network (fronthaul). Time-wavelength division multiplexing (TWDM) passive optical network (PON) is a promising fronthaul solution due to its low energy consumption and high capacity. In this paper, we propose and leverage the concept of a virtual base station (VBS), which is dynamically formed for each cell by assigning virtualized network resources, i.e., a virtualized fronthaul link connecting the DU and RU, and virtualized functional entities performing baseband processing in DU cloud. We formulate and solve the VBS formation (VF) optimization problem using an integer linear program (ILP). We propose novel energy-saving schemes exploiting VF for both the network planning stage and traffic engineering stage. Extensive simulations show that CRAN with our proposed VF schemes achieves significant energy savings compared to traditional RAN and CRAN without VF.

A distributed approach to measure IP traffic matrices

Abstract: The traffic matrix of a telecommunications network is an essential input for any kind of network design and capacity planning decision. In this paper we address a debate surrounding traffic matrix estimation, namely whether or not the costs of direct measurement are too prohibitive to be practical. We examine the feasibility of direct measurement by outlining the computation, communication and storage overheads, for traffic matrices defined at different granularity levels. We illustrate that today's technology, that necessitates a centralized solution, does indeed incur prohibitive costs. We explain what steps are necessary to move towards fully distributed solutions, that would drastically reduce many overheads. However, we illustrate that the basic distributed solution, in which flow monitors are on all the time, is excessive and unnecessary. By discovering and taking advantage of a key stability property underlying traffic matrices, we are able to propose a new scheme that is distributed and relies only on a limited use of flow measurement data. Our approach is simple, accurate and scalable. Furthermore, it significantly reduces the overheads above and beyond the basic distributed solution. Our results imply that direct measurement of traffic matrices should become feasible in the near future.