Simulating Cellular Communications in Vehicular Networks: Making SimuLTE Interoperable with Veins

The evolution of cellular technologies toward 5G progressively enables efficient and ubiquitous communications in an increasing number of fields. Among these, vehicular networks are being considered as one of the most promising and challenging applications, requiring support for communications in high-speed mobility and delay-constrained information exchange in proximity. In this context, simulation frameworks under the OMNeT++ umbrella are already available: SimuLTE and Veins for cellular and vehicular systems, respectively. In this paper, we describe the modifications that make SimuLTE interoperable with Veins and INET, which leverage the OMNeT++ paradigm, and allow us to achieve our goal without any modification to either of the latter two. We discuss the limitations of the previous solution, namely VeinsLTE, which integrates all three in a single framework, thus preventing independent evolution and upgrades of each building block.Comment: Published in: A. Foerster, A. Udugama, A. Koensgen, A. Virdis, M. Kirsche (Eds.), Proc. of the 4th OMNeT++ Community Summit, University of Bremen - Germany - September 7-8, 201

System-level analysis of the tradeoffs between power saving and capacity/QoS with DRX in LTE

In an LTE cell, Discontinuous Reception (DRX) allows the central base station to configure User Equipment for periodic wake/sleep cycles, so as to save energy. Several parameters are associated to DRX operations, thus allowing for optimal performance with different traffic profiles (i.e., CBR-like, bursty, periodic arrivals of variable-sized packets, etc.). This work investigates how to configure these parameters and explores the tradeoff between power saving, on one side, and per-user QoS and cell capacity, on the other. Unlike previous work, mostly based on analytical models neglecting key aspects of LTE, our evaluation is carried out using a fully-fledged packet simulator. This allows us to discover previously unknown relationships and to propose configuration guidelines for operators

A comprehensive simulation analysis of LTE Discontinuous Reception (DRX)

In an LTE cell, Discontinuous Reception (DRX) allows the central base station to configure User Equipments for periodic wake/sleep cycles, so as to save energy. DRX operations depend on several parameters, which can be tuned to achieve optimal performance with different traffic profiles (i.e., CBR vs. bursty, periodic vs. sporadic, etc.). This work investigates how to configure these parameters and explores the trade-off between power saving, on one side, and per-user QoS, on the other. Unlike previous work, chiefly based on analytical models neglecting key aspects of LTE, our evaluation is carried out via simulation. We use a fully-fledged packet simulator, which includes models of all the protocol stack, the applications and the relevant QoS metrics, and employ factorial analysis to assess the impact of the many simulation factors in a statistically rigorous way. This allows us to analyze a wider spectrum of scenarios, assessing the interplay of the LTE mechanisms and DRX, and to derive configuration guidelines

Performance evaluation of TCP-based traffic over direct communications in LTE-Advanced

Direct (or device-to-device, D2D) communications are being investigated in the framework of LTE-Advanced. They allow one-to-one communications between two endpoints, under the control of the eNodeB, which allocates resources for the d2d flow, but does not act as a relay for its traffic. The direct link can also be used for file transfer or proximity-based browsing, i.e. applications running on TCP. In this paper, we evaluate the performance of TCP-based traffic transported through the direct link, in several scenarios. We show and explain non-intuitive results, which arise from the interplay of TCP and LTE-A protocol mechanisms, and compare the existing TCP versions in a dynamic environment, where mode switches between the direct and the infrastructure link may induce periodic losses

Automating Large-Scale Simulation and Data Analysis with OMNeT++: Lession Learned and Future Perspectives

Simulation is widely adopted in the study of modern computer networks. In this context, OMNeT++ provides a set of very effective tools that span from the definition of the network, to the automation of simulation execution and quick result representation. However, as network models become more and more complex to cope with the evolution of network systems, the amount of simulation factors, the number of simulated nodes and the size of results grow consequently, leading to simulations with larger scale. In this work, we perform a critical analysis of the tools provided by OMNeT++ in case of such large-scale simulations. We then propose a unified and flexible software architecture to support simulation automation

Modeling unicast device-to-device communications with SimuLTE

In LTE-Advanced (LTE-A), device-to-device (D2D) transmissions allow two peering User Equipments to communicate directly without using the Evolved Node-B as relay. D2D is regarded as one of the enablers to bring LTE-A in the context of vehicular networks, smart cities, or M2M applications. Research on this topic is mostly carried out through link-level simulations. In this work, we describe instead the modeling of D2D into a system-level simulator, namely SimuLTE, which enables us to analyze the performance of applications and higher-layer protocols using D2D transmission. We first describe the modeling within the SimuLTE architecture, then we validate it and analyze the performance of D2D communications with frequency reuse

Simulating device-to-device communications in OMNeT++ with SimuLTE: scenarios and configurations

SimuLTE is a tool that enables system-level simulations of LTE/LTE-Advanced networks within OMNeT++. It is designed such that it can be plugged within network elements as an additional Network Interface Card (NIC) to those already provided by the INET framework (e.g. Wi-Fi). Recently, device-to-device (D2D) technology has been widely studied by the research community, as a mechanism to allow direct communications between devices of a LTE cellular network. In this work, we present how SimuLTE can be employed to simulate both one-to-one and one-to-many D2D communications, so that the latter can be exploited as a new communication opportunity in several research fields, like vehicular networks, IoT and machine-to-machine (M2M) applications

Simulating LTE/LTE-Advanced Networks with SimuLTE

In this work we present SimuLTE, an OMNeT++-based simulator for LTE and LTE-Advanced networks. Following well-established OMNeT++ programming practices, SimuLTE exhibits a fully modular structure, which makes it easy to be extended, verified, and integrated. Moreover, it inherits all the benefits of such a widely used and versatile simulation framework as OMNeT++, i.e., experiment support and seamless integration with the OMNeT++ network modules, such as INET. This allows SimuLTE users to build up mixed scenarios where LTE is only a part of a wider network. This paper describes the architecture of SimuLTE, with particular emphasis on the modeling choices at the MAC layer, where resource scheduling is located. Furthermore, we describe some of the verification and validation efforts and present an example of the performance analysis that can be carried out with SimuLTE

A fast and reliable broadcast service for LTE-advanced exploiting multihop device-to-device transmissions

Several applications, from the Internet of Things for smart cities to those for vehicular networks, need fast and reliable proximity-based broadcast communications, i.e., the ability to reach all peers in a geographical neighborhood around the originator of a message, as well as ubiquitous connectivity. In this paper, we point out the inherent limitations of the LTE (Long-Term Evolution) cellular network, which make it difficult, if possible at all, to engineer such a service using traditional infrastructure-based communications. We argue, instead, that network-controlled device-to-device (D2D) communications, relayed in a multihop fashion, can efficiently support this service. To substantiate the above claim, we design a proximity-based broadcast service which exploits multihop D2D. We discuss the relevant issues both at the UE (User Equipment), which has to run applications, and within the network (i.e., at the eNodeBs), where suitable resource allocation schemes have to be enforced. We evaluate the performance of a multihop D2D broadcasting using system-level simulations, and demonstrate that it is fast, reliable and economical from a resource consumption standpoint

Simulating Cellular Communications in Vehicular Networks: Making SimuLTE Interoperable with Veins

The evolution of cellular technologies toward 5G progressively enables efficient and ubiquitous communications in an increasing number of fields. Among these, vehicular networks are being considered as one of the most promising and challenging applications, requiring support for communications in high-speed mobility and delay-constrained information exchange in proximity. In this context, simulation frameworks under the OMNeT++ umbrella are already available: SimuLTE and Veins for cellular and vehicular systems, respectively. In this paper, we describe the modifications that make SimuLTE interoperable with Veins and INET, which leverage the OMNeT++ paradigm, and allow us to achieve our goal without any modification to either of the latter two. We discuss the limitations of the previous solution, namely VeinsLTE, which integrates all three in a single framework, thus preventing independent evolution and upgrades of each building block