Introduction

In NetSim’s Internetworks library, wireless nodes connect to an Access Point (AP) while in NetSim’s LTE and 5G libraries, the mobile nodes (UEs) connect to base stations (eNBs, gNBs). There is no such association between the wireless stations and any fixed infrastructure in MANETs.

A Mobile Ad hoc Network (MANET) is an autonomous system of mobile nodes. In such networks, information transport services are built over a set of arbitrarily located nodes, which are possibly mobile. Every node behaves both like a mobile host and as a wireless router. There are many obvious applications for such networks, including emergency communications, vehicular communications, and military applications, etc.

Such networks have dynamic (sometimes rapidly changing), random, multi-hop topologies that are composed of relatively bandwidth-constrained wireless links. MANETs must therefore support efficient operation in mobile wireless environments by incorporating routing functionality into mobile nodes. Note that such multi-hop networks exploit spatial reuse; transmissions can occur simultaneously on links that are sufficiently separated in space.

In NetSim MANETs, data packets are sent between source-destination pairs by multi-hop relaying. The MANETs in NetSim may operate in isolation or may have bridge nodes to interface with other networks (wired networks or even other MANETs).

NetSim MANET library supports the following protocols [1]. - Layer 3 Unicast Routing

  • Dynamic Source Routing (DSR)

  • Ad hoc On demand Distance Vector Routing (AODV)

  • Optimized Link state Routing (OLSR)

  • Zone Routing Protocol (ZRP)

  • MAC / PHY (interfaced from NetSim Internetworks library)

  • 802.11 a, b, g, n, ac. p and e

NetSim MANETs component can be interfaced with:

  • NetSim Component 6 (IOT) module to run 802.15.4 in MAC/PHY

  • NetSim Component 9 (VANETs) module to run IEEE 1609 WAVE in MAC/PHY

  • NetSim TDMA Radio Networks (Add on) to run TDMA/DTDMA in MAC/PHY

_images/Figure-110.png

Figure-1: A typical Cognitive Radio Network scenario in NetSim. The topology shows two CR Base Stations communication with CR CPEs and connected to an external network via a Router

_images/Figure-210.png

Figure-2: The Result dashboard and Plot window shown in NetSim after completion of simulation

The digital communication system employed, the transmit power used, and the radio propagation characteristics of the environment determine the “links” in the network.

Performance analysis of wireless ad hoc networks is a challenging task because such analysis must consider the interactions between the wireless physical layer, radio propagation, multiple access, random topology, routing, and the characteristics of the application that generates the traffic carried by the network. Therefore, unlike wired and fixed-topology networks, understanding and optimizing the performance of MANETs is a difficult undertaking owing to the complex interaction between the various “layers” of the network.