DOWNLOAD MY Ph.D Thesis - UNAM

Chapter 4Simulation and analytical modelling p4.3.3 Interactive Network Adaptor designThe Interactive Network Adapter (INA) node consists of the IA MAC and four linkaccess points to interact to the CATV network, the Network Cloud and StatisticsCollection node as pointed out in Figure 4.9a.The representation of the INA into an OPNET node is shown in Figure 4.9b. Here theIA MAC was connected to the downstream bus access point via a statistical wire, thuspreventing the IA MAC sending another frame to the bus. Currently, the trafficgenerator (Downstream source) has been disabled, thus no data packet would betransmitted downstream, since the main research focuses on the performance analysis ofthe upstream channel, which is the only critical network resource because of thereservation access mechanism and its marked asymmetry. In addition, the upstreamscheduler is part of the IA Manager process.The IA MAC node is also modelled as two asynchronous processes, the IA Managerand the IA Transmitter (TX) process. The IA Manager process handles the MACInitialisation (which consists of initialisation, provisioning, ranging, calibration andconnection signalling), receipt of upstream packets and downstream traffic. The IA TxController handles transmission of data and MAC signalling messages generated by theIA Manager process.a) INA Designb) INA Representation in OPNETPacket-OutPacket-OutStatisticsCollectionINA MACIAManagerTransmitterSystemfrom_network_cloud_txto_network_cloud_txto_stat_collection_txDowstreamTrafficIA TxControllerReceiverSystemINA_MACDownstream_sourcePacket-InPacket-Infrom_bus_rxto_bus_txFigure 4.9 – INA node description.4-12