Realistic Traffic Profiles Research Articles

Quantifying Bypass Traffic in Partially Meshed Transparent Optical Networks

This work investigates the transparent bypassing capacity requirements of elastic backbone optical networks to determine the all-optical cross-connection capacity needed at network nodes. Topological parameters have been used to develop a random network generator, and the generated topologies are evaluated. Reference values are obtained and applied to well-known topologies, and extensive simulations are conducted to obtain network nodes' bypassing traffic under realistic traffic profiles. The study reveals that although bypassing traffic varies by topology, it never exceeds 9% of total network traffic per node degree. These findings can help properly dimension network nodes by determining the necessary quantity of transceivers and cross-connection capacity based on the network topology and expected traffic.

Assessing the Scalability of Next-Generation Wavelength Switched Optical Networks

We are currently facing two major challenges for the development of future photonic networks: scalability and cost/energy efficiency. The process of evaluating the impact on the network of the expected increase of traffic demand is called scalability analysis. It is one of the most important tasks for a network designer, along with minimizing energy consumption and cost. In this paper, we propose a novel approach to assess wavelength switched optical network (WSON) scalability and efficiency. Our method takes into account the routing constraints of reconfigurable optical add/drop multiplexers (ROADMs), a variety of coherent transmission systems, different amplification schemes and types of fibre. We have assessed the network scalability and the roadmap for technological upgrades by running simulations of the recently deployed Telecom Italia's WSON Kaleidon. We have used realistic traffic profiles and traffic growth-rate projections under a variety of case studies of practical interest. This study provides an innovative tool and insights to drive network designers' decisions based on the impact of present and future photonic technologies.

A local search heuristic to solve the planning problem of 3G UMTS all-IP release 4 networks with realistic traffic

The purpose of this paper is to develop an efficient heuristic in order to solve the planning problem of 3rd Generation 3G Universal Mobile Telecommunication System UMTS all-IP Release 4 networks. Since the problem is NP-hard, an approximate algorithm based on the local search principle is proposed. Targeting a realistic planning tool, a realistic traffic profile was taken from real live networks. To evaluate the efficiency of the proposed heuristic, a comparative study in which the results are compared with respect to a reference model is conducted. Numerical analysis demonstrates that the local search algorithm produces solutions that are, on average, within 5.03% of the optimal solution, and in the best and worst cases at 0.87% and 9.29% of the optimal solution respectively.

Automatic planning of 3G UMTS all-IP release 4 networks with realistic traffic

Most Universal Mobile Telecommunications Systems (UMTS) service providers are switching to an all-IP (also called flat-IP) architecture. Using an all-IP architecture within 3G networks provides a cost-effective transport network since the same infrastructure can be used for both voice and data services. However, planning and designing such an architecture is very complex especially if realistic traffic profiles are taken into consideration. As a result, this paper first provides a mathematical formulation (presented in Appendix for readability reasons) for the global planning problem of 3G UMTS all-IP Release 4 networks with realistic traffic profile. Due to the complexity of the problem, heuristics based on local search and tabu search are also proposed. Finally, a comparative study is performed to evaluate how good the heuristics are with respect to a reference model. Results show that the tabu search is able to provide solutions that are close to optimal solutions in a much shorter computation time.

EDXY – A low cost congestion-aware routing algorithm for network-on-chips

In this paper, an adaptive routing algorithm for two-dimensional mesh network-on-chips (NoCs) is presented. The algorithm, which is based on Dynamic XY (DyXY), is called Enhanced Dynamic XY (EDXY). It is congestion-aware and more link failure tolerant compared to the DyXY algorithm. On contrary to the DyXY algorithm, it can avoid the congestion when routing from the current switch to the destination whose X position (Y position) is exactly one unit apart from the switch X position (Y position). This is achieved by adding two congestion wires (one in each direction) between each two cores which indicate the existence of congestion in a row (column). The same wires may be used to alarm a link failure in a row (column). These signals enable the routing algorithm to avoid these paths when there are other paths between the source and destination pair. To assess the latency of the proposed algorithm, uniform, transpose, hotspot, and realistic traffic profiles for packet injection are used. The simulation results reveal that EDXY can achieve lower latency compared to those of other adaptive routing algorithms across all workloads examined, with a 20% average and 30% maximum latency reduction on SPLASH-2 benchmarks running on a 49-core CMP. The area of the technique is about the same as those of the other routing algorithms.

A Novel Synthetic Traffic Pattern for Power/Performance Analysis of Network-on-Chips Using Negative Exponential Distribution

In this paper, we present an empirically-derived synthetic traffic model based on the Negative Exponential Distribution (NED) for homogenous and heterogeneous Network-on-chips (NoCs) with any dimensionality. Compared to conventional synthetic traffic profiles, this synthetic traffic profile accurately captures key statistical behavior of realistic traces obtained by running different applications on Network-on-chips. To assess the usefulness of this new NoC traffic model, the average packet hops for the proposed traffic profile is compared with those of some synthetic and realistic traffic patterns. The results show that the NED traffic profile has more similarity with the realistic traffic profiles than those of conventional synthetic ones. Adding this traffic profile to the existing profiles, improves the design and characterization of NoCs.

GSE: A flexible, yet efficient, encapsulation for IP over DVB‐S2 continuous generic streams

AbstractThe second‐generation specification for Digital Video Broadcast over Satellite, DVB‐S2, defines an improved and adaptive physical layer. A new framing structure at the link layer, known as the generic stream (GS), is introduced offering an alternative to the well‐known MPEG transport stream (TS). This paper presents the requirements for and the design of an encapsulation protocol to transport IPv4 and IPv6 datagrams and other network protocol packets directly over DVB‐S2 using this GS profile. The resulting generic stream encapsulation (GSE) is a novel method that provides flexible encapsulation with support for fragmentation. A flexible extension header format allows GSE to carry additional header information, suitable for enhanced features, such as link layer encryption and IP header compression. The paper assesses GSE performance by simulation using realistic traffic profiles and attenuation fading. This demonstrates considerable improvement in efficiency compared with the MPE/MPEG‐2 TS, especially when used with adaptive coding and modulation (ACM). Although designed for DVB‐S2 systems, the new encapsulation is suitable for other second‐generation physical layer standards. Copyright © 2008 John Wiley & Sons, Ltd.