OPNET Platform Research Articles

Design and Performance Testing of a Simulation Model for Time-Triggered Ethernet

Abstract Time-Triggered Ethernet (TTEthernet) is a new hybrid transmission network technology that introduces time-triggered, synchronization, and security mechanisms based on traditional Ethernet. It is difficult to verify the overall performance mechanism of the TTEthernet through manual calculation. Therefore, this paper models the TTEthernet End System and Switch, and simulates the overall performance of the TTEthernet Model based on the OPNET platform. Firstly, this paper introduces the key mechanisms and development status of the TTEthernet. Secondly, the simulation modeling of the TTEthernet End System and Switch are described, and the key technologies within the model are explained; The End system is an important component of the network, responsible for data generation, transmission, and processing. The Switch is responsible for data forwarding and routing, which plays a crucial role in the performance and stability of the network. Finally, the performance of the TTE network model in this article is analyzed through simulation data, verifying the timeliness, determinacy, and reliability of the model. Simulation data shows that the global throughput of the TTE network model in this article is stable at around 70Mbps, the End-to-End Delay of TT services is around 2.5ms, and the packet loss rate is almost zero, which meets the expected results. However, RC and BE services have higher end-to-end latency and packet loss rates than TT services due to their event triggered messages, but they still meet expectations.

Threshold‐based key management scheme for space network

SummaryThe data link protocols proposed by the Consultative Committee for Space Data Systems (CCSDS) is widely used in space missions. However, the current space key management schemes are inefficient in scalability, security, and key update. In this work, a threshold‐based spatial key management scheme is proposed and applied to the CCSDS telecommunication control (TC) protocol to ensure the security of spatial networks. The threshold‐based key management algorithm using LDPC code is designed to generate, distribute, update, and deactivate the master key. The bilinear pairing cryptosystem is used to protect the group key and provide authentication. The security and performance of the proposed scheme are analyzed. Furthermore, the network model, node model, and process model of CCSDS‐TC protocol based on the proposed scheme are constructed and simulated on OPNET platform. The result shows that the storage overhead of the proposed scheme is lower than the improved Shamir and ECC‐based key management schemes. Its computational overhead is approximately changeless, whereas the network scale is increasing. Furthermore, the proposed scheme only uses binary multiplication, which takes lower computation overhead. Therefore, the proposed scheme has higher security, scalability, and low resource consumption.

Research on effective jamming style of projectile-carried communication for FH communication radio under common modulation systems

This work addresses the effective jamming style of projectile-carried communication for frequency hopping radio with different modulation by applying simulation verification via OPNET platform to construct the projectile-carried communication jamming system model. A general projectile-carried communication jamming style based on the signal combination of sweep saw-tooth wave and noise frequency modulation is proposed and analyzed. The network model of projectile-carried communication jamming system is constructed, and then the model building process of frequency hopping radio from the two aspects of transmitter model and receiver model is deeply elaborated. We demonstrate that the general projectile-carried communication jamming style has good jamming effect on the frequency hopping radio receivers with five modulation modes of 2FSK, 2PSK, 2DPSK, MSK and GMSK by comparing the simulation results, including receiving throughput, end-to-end delay, time delay of wireless channel access, delivery rate of synchronized header message, signal-to-noise ratio, bit error rate, packet loss rate, remaining power of jammer. Among them, the bit error rate of radio receiver with five modulation modes is more than 20%.

Design and implementation of dynamic high-speed switches in super base station architectures

Novel centralized base station architectures integrating computation and communication functionalities have become important for the development of future mobile communication networks. Therefore, the development of dynamic high-speed interconnections between baseband units (BBUs) and remote radio heads (RRHs) is vital in centralized base station design. Herein, dynamic high-speed switches (HSSs) connecting BBUs and RRHs were designed for a centralized base station architecture. We analyzed the characteristics of actual traffic and introduced a switch traffic model suitable for the super base station architecture. Then, we proposed a data-priority-aware (DPA) scheduling algorithm based on the traffic model. Lastly, we developed the dynamic HSS model based on the OPNET platform and the prototype based on FPGA. Our results show that the DPA achieves close to 100% throughput with lower latency and provides better run-time complexity than iOCF and HE-iSLIP, thereby demonstrating that the proposed switch system can be adopted in centralized base station architectures.

A BUS‐aided RSU access scheme based on SDN and evolutionary game in the Internet of Vehicle

SummaryThe Internet of Vehicle (IoV) is known as a kind of highly dynamic network, in which the vehicle needs to exchange information with the fixed Roadside Unit (RSU) or other moving vehicles frequently. In order to improve the performance of existing RSU access schemes, in this paper, we proposed a BUS‐aided RSU connection scheme based on the software‐defined networking (SDN) and evolutionary game theory, in which the costs during multiple‐user access and following RSU handoff are considered. At first, we constructed a SDN‐IoV architecture and showed the benefits by introducing SDN into IoV. After that, we modified the original OpenFlow protocol stack in order to apply it to the wireless vehicular networks. Next, to explore more accessing opportunities in moving cases, the BUS was further introduced as a mobile RSU. With these fixed and mobile RSUs, an evolutionary game is then envisioned to model the multiple‐user access process with the aim to maximize the rewards of all participants. To make our proposed protocol practical, we also illustrated the implementation procedure of our protocol on the OPNET platform and gave out the finite state machine (FSM) of major routines. Numerical results showed that our proposed scheme could outperform the schemes without BUS, SDN, and game theory enabled, in terms of RSU load ratio, throughput, and handoff times.

Influence Analysis of Typical Operational Environment on the Use of Projectile-carried Communication Jammer on the OPNET Platform

Influence Analysis of Typical Operational Environment on the Use of Projectile-carried Communication Jammer on the OPNET Platform

OPNET平台下视频会议系统性能的半实物仿真方法探析

OPNET平台下视频会议系统性能的半实物仿真方法探析

A Mobility-Based Routing Protocol for CR Enabled Mobile Ad Hoc Networks

With the fast development of hardware and chipset functionality and capability, smart devices equipped with advanced technologies, such as Cognitive Radio (CR) will offer promising opportunities for mobile network. The authors in this work design a mobility based routing protocol (CRMBR) which operates in CR enabled Mobile Ad hoc Networks (MANETs). The adopted cross layer structure transfers the cognitive sensing data, such as channel quality and available bandwidth, from Physical layer up to MAC/Network layers periodically. Network layer uses such information for executing route selection algorithm while MAC layer runs the sub-channel scheduling algorithm based on CR data before each transmission. CRMBR further employs an advanced acknowledgment scheme in MAC layer for sub-channel selection to reduce the control overhead while forwarding data in MANETs. The performance of CRMBR is investigated via simulations on OpNET platform and the results confirm its favorable operation within CR MANET environments compared to two classic routing protocols in Ad hot networks: AODV and DSR.

Differentiated cooperative multiple access for multimedia communications over fading wireless networks

The quality of service (QoS) support for multimedia communications faces a big challenge in a fading wireless network. On one hand, conventional automatic repeat request (ARQ) schemes are not effective for small-scale fading channels with correlated errors due to consecutive retransmission failures. On the other hand, large-scale fading due to propagation loss or shadowing severely limits transmission range. A novel differentiated cooperative medium access control (MAC) protocol, called DC-MAC, is proposed to enhance the QoS support for multimedia communications while supporting service differentiation based on the IEEE 802.11e architecture. By enabling cooperative ARQ, the retransmission is initiated from an appropriate transmission queue of an appropriate relay node instead of the original source. Since unnecessary and useless retransmissions may intensify the node contention and degrade the system performance contrarily, a novel negative acknowledgement feedback mechanism is introduced for loss distinguishing and channel estimation such that cooperative retransmission will be employed only when necessary and only by competent nodes. Extensive simulations are conducted on the OPNET platform to analyse the performances of DC-MAC under both small-scale and large-scale fading. Simulation results show that the proposed scheme significantly improves the performances of both multimedia applications and best-effort data applications in terms of throughput, delay and coverage with moderate user contention.

Performance Impairments in Single-Mode Radio-Over-Fiber Systems Due to MAC Constraints

This paper investigates performance impairments due to constraints imposed by the MAC layer when single-mode fiber (SMF) is used to extend the reach of an IEEE 802.11 network. It is shown that data throughput decreases as fiber length increases. It is also noted that the network fails long before physical layer limitations set in due to the timeout values defined within the MAC protocol. This study is based on both variants of the IEEE 802.11 Distributed Coordination Function. Moreover, both UDP and TCP packet transmissions are taken into account. An experimental enquiry is initially developed to provide a set of validation points before extending these results by simulations using the OPNET platform. Finally, an analytical approximation is presented to these results that allows designers of Radio-over-fiber (RoF) systems to quickly and accurately predict the data throughput given the specific parameters of their network. To our knowledge, this is the first analysis of this kind for a long reach fiber system.