Pure Packet Research Articles

Design of Optoelectronic Hybrid Switching High Performance Computing Internet

Optoelectronic hybrid network technology is mixed with pure electric packet switching network, which can improve network capacity and reduce power consumption. However, the long configuration time and complex management of optical circuit switch affect the performance of optoelectronic hybrid network. Therefore, a new optoelectronic hybrid network architecture (BET) is designed. The network architecture consists of Ethernet electric packet switching network and optical wavelength routing network. The signal receiving and dispatching of optical routing network is realized by circular arrayed waveguide grating router. Based on the characteristics of wavelength cycling routing, there is no need to adjust the routing of optical signals to the destination port, that is, there is no need to configure the optical wavelength routing network. At the same time, an intelligent node dynamic reconfiguration (RG) algorithm is designed to improve the resource utilization of optical nodes. In this method, the network link utilization, cache occupancy, and network load are taken into account to adjust the distribution of optical nodes in the optoelectronic hybrid network. In the process of the experiment, by changing the message length, it is found that the optical wavelength routing network can achieve large capacity and new-type transmission and effectively reduce the delay at the same time; on the optoelectronic hybrid network, with the help of Hadoop platform, distributed cluster is built and used to transmit an XML data encoding (ED code), solve the finite state transducers (FST) and encode them. Compared with the traditional electric packet switching network, the transmission delay of ED code is greatly reduced after the introduction of optical circuit switch, and the efficiency of FST solution and coding calculation is improved by at least 30%.

Optoelectronic Hybrid Network Architecture and Its Performance Analysis

Optoelectrical hybrid network technology is introduced into a network based on pure electrical packet switching, which increases network capacity and reduces power consumption. However, the problems of long configuration time and complex management of optical circuit switches affect the performance of hybrid optoelectrical networks. A new type of hybrid optoelectronic network architecture (HOEP) cooperated by Ethernet packet switching network and optical wavelength routing network was designed in the study. The optical routing network transmitted and received optical signals by using a circular array waveguide grating router, and transmitted the optical signal carrying data to the target port based on the characteristics of wavelength cyclic routing. The entire process only needed to modulate the data signal, and did not need to configure the optical wavelength routing network. At the same time, in order to further improve the resource utilization of optical nodes, a kind of intelligent node dynamic reconstruction (RC) algorithm was designed. Combining with network link utilization, cache occupancy, and network load value, this method could dynamically adjust the usage distribution of optical nodes for reconstruction. During the experiment, the RC algorithm was applied to the HOEP network architecture. Compared with other typical network architectures, the HOEP network proposed in the study can effectively reduce the network cost, power consumption, and improve network throughput. Moreover, the introduction of RC algorithm and network equipment can make the cost remain within the controllable range, while it can further increase the network throughput and reduce the power consumption of the HOEP network, thereby meeting the dynamic demand for network bandwidth with larger data traffic.

LTE Capacity Estimation with Changing Different Planning Parameters

Capacity improvement is the essential advantages in 4th generation mobile systems which called Long-Term Evolution (LTE). The maximum data transmission rate of LTE cell is 100 Mb/s in downlink direction and 50Mb/s in uplink, and this rate can be enhanced with deploying different techniques like MIMO, carrier aggregation, and many others. Because of that 4G-LTE mobile network is considered pure packet switching, there are many parameters which affect the maximum cell capacity. This study will evaluate the result of changing many parameters on the maximum mobile cell capacity. The aim is to extract the best values of the different parameters to maximize LTE mobile cell capacity.

The Two-Step P2P Simulation Approach

In this article a framework is introduced that can be used to analyse the effects & requirements of P2P applications onapplication and on network layer. P2P applications are complex and deployed on a large scale, pure packet level simulations do not scale well enough to analyse P2P applications in a large network with thousands of peers. It is also difficult to assess the effect of application level behavior on the communication system. We therefore propose an approach starting with a more abstract and therefore scalable application level simulation. For the application layer a specific simulation framework wasdeveloped. The results of the application layer simulations plus some estimated background traffic are fed into a packet layer simulator like NS2 (or our lab testbed) in a second step to perform some detailed packet layer analysis such as loss and delay measurements. This can be done for a subnetwork of the original network to avoid scalability problems.

Analysis of Power Consumption in Future High-Capacity Network Nodes

Power consumption and the footprint of future network elements are expected to become the main limiting factors for scaling the current architectures and approaches to capacities of hundreds of terabits or even petabits per second. Since the underlying demand for network capacity can be satisfied only by contemporaneously increasing transmission bit rate, processing speed, and switching capacity, it unavoidably will lead to increased power consumption of network nodes. On the one hand, using optical switching fabrics could relax the limitations to some extent, but large optical buffers occupy larger areas and dissipate more power than electronic ones. On the other hand, electronic technology has made fast progress during the past decade regarding reduced feature size and decreased power consumption. It is expected that this trend will continue in the future. This paper addresses power consumption issues in future high-capacity switching and routing elements and examines different architectures based on both pure packet-switched and pure circuit-switched designs by assuming either all-electronic or all-optical implementation, which can be seen as upper and lower bounds regarding power consumption. The total power consumption of a realistic and appropriate technology for future high-performance core network nodes would probably lie somewhere between those two extreme cases. Our results show that implementation in optics is generally more power efficient; especially circuit-switched architectures have a low power consumption. When taking into account possible future developments of Si CMOS technology, even very large electronic packet routers having capacities of more than hundreds of terabits per second seem to be feasible. Because circuit switching is more power efficient and easier to implement in optics than pure packet switching, the scalability limitation due to increased power consumption could be considerably relaxed when a kind of dynamic optical circuit switching is used within the core network together with an efficient flow aggregation at edge nodes.

High-Performance Simulation of Low-Resolution Network Flows

Simulation of large-scale networks demands that we model some flows at coarser time scales than others, simply to keep the execution cost manageable. This article studies a method for periodically computing traffic at a time scale larger than that typically used for detailed packet simulations. Applications of this technique include computation of background flows (against which detailed foreground flows are simulated) and simulation of worm propagation in the Internet. The approach considers aggregated traffic between Internet points of presence (POPs) and computes the throughput of each POP-to-POP flow through each router on its path. This problem formulation leads to a nonlinear system of equations. The authors develop means of reducing this system to a smaller set of equations, which are solved using fixed-point iteration. They study the convergence behavior, as a function of traffic load, on topologies based on Internet backbone networks. They find that the problem reduction method is very effective and that convergence is achieved rapidly. The authors also examine the comparative speedup of the method relative to using pure packet simulation for background flows and observe speedups exceeding 3000 using an ordinary PC. They also simulate foreground flows interacting with background flows and compare the foreground behavior using their solution with that of pure packet flows. They find that these flows behave accurately enough in their approach to justify use of the technique in their motivating application. The authors parallelize the algorithm on a distributed-memory multiprocessor. They exploit the flexibility offered by noncommittal barrier synchronization that permits a processor to handle computation messages even after it invokes a barrier primitive. They also take advantage of application-specific knowledge to minimize synchronization cost, study the performance of their parallel algorithm with both fixed and scaled problem sizes, and observe excellent scalability on a multiprocessor supercomputer.

All-optical header processing system based on time-to-wavelength conversion for pure DPSK packets

Presented is a novel asynchronous all-optical header processing system for pure DPSK packets based on time-to-wavelength conversion of the header information that requires only four optical functions independently of the number of headers. Experimental results at 12.5 Gbit/s demonstrate that four DPSK headers are distinguished at four distinct outputs. The system requires low optical power, is highly scalable, and allows for potentially high-speed operation and photonic integration in a single chip.

All-optical header recogniser for pure DPSK optical packets

A novel low power and asynchronous all-optical header recogniser for pure DPSK packets based on narrow filtering and optical correlators is demonstrated. Experimental results show the recognition of two different packet headers at 12.5 Gbit/s at two distinct outputs. This concept can be extended to distinguish a larger number of headers at distinct outputs, to operate at higher bit rate and can be used in devising an all-optical packet switch.

Integrated Voice/Data Packet Switching Techniques for Future Military Networks

Virtual circuit and pure packet (datagram) based switching techniques are studied for future application to the integrated voice/data telecommunications. The coexistence of voice with both interactive and bulk data in an integrated network suggests the desirability of a mixed switching technique to allow the efficient sharing of both the switching and communications resources. Such a mixed packet switching scheme is also evaluated. It uses virtual circuit for regular traffic (voice and bulk data), and uses pure packet (datagram) for bursty traffic (interactive and query/response). It also adapts to changes in voice/ data input traffic mixture.