How do I use the standard IP models to simulate a Wireless IP scenario ?

How do I use the standard IP models to simulate a Wireless IP scenario ?

This information may be useful to the non-advanced users of IP. Here is a simple step-by-step procedure I followed to verify that the OPNET standard model for IP does indeed work with radio links. 1. Create a node model of a router with one point-to-point link and one radio link (one radio transmitter and radio receiver object) by suitably modifying a standard router model (e.g.. ethernet8_slip4_gtwy). In this node model, the following must be configured: a) Add an extended attribute ip addr index to each packet stream connecting the ip QP to the lower layer object. For the packet stream pair within each interface (upstream and downstream) this index should have the same value. The packet streams corresponding to different interfaces should be indexed with a different index with values running from zero tomaximum-number-of-interfaces - 1.b) The IP addresses should be assigned manually. Here, it is important to match the ip addr index set in the previous step to the row number of the corresponding interface address in the IP Interface Information compound attribute (with version 8.0 and beyond, please refer to IP Routing Parameters | Interface Information). The Loopback Interface address should also be set manually. Ensure that none of the interfaces are shutdown. 2. Create a node model of a mobile radio. This can be easily done by modifying a standard client model (the advanced version) (e.g.. Replace the point-to-point Rx/Tx objects with radio Rx and Tx objects). In this node model, ensure that the following is configured. a) As a matter of convenience you can set the closure model to dra_closure_all (to ensure link closure irrespective of earth curvature). You'll have to ensure that the link is good at some point during the simulation by othermeans. Leave the closure model as dra_closure if you need to consider the effects of earth's curvature. The transmitter and receiver channel should be separated in frequency so that the radio does not receive its own transmissions. b) Under IP Host Parameters, set Interface Information->Address and Default Route manually (in version 8.0 and beyond, IP Routing Parameters | Interface Information | Address and IP Routing Parameters | Default Route). 3. Any other node connected to the router should also have addresses manually assigned. With the network set up as described, packets should be routed successfully across the radio link. As an additional note, with version 8.0 and beyond, please refer to the Wireless_LAN project (e.g., scenario wlan_routed_network) for an example of the use of IP nodes with wireless and wired interfaces (it shows examples of end devices and router devices with wireless and wired interfaces). Here is another very simple approach to interface the IP layer to a wireless interface using an external radio node. Follow the directions below to create a radio modem node.1.Create a new node model.2.Copy an SLIP/PPP interface (a transmitter-receiver pair connected by an association) from an existing a PPP router or workstation node model and copy onto the new node model3.Add a radio transmitter and receiver to the node model4.Connect the point-to-point receiver to the radio transmitter and vice-versa using the packet streams.5.Set the altitude attribute value to 100 from interfaces->node interfaces menu6.Promote the channel data rate and min frequency attribute from the radio transmitter and receiver moduleOnce the radio node model is ready, follow the directions below to create a radio IP scenario.1.Start from an existing working scenario which has two routers connected through a PPP link2.Remove the PPP link3.Place two radio models created from previous step between the two routers4.Connect the routers to the radio nodes using PPP links (preferably using the same ports that was used before in order not to manually assign IP addresses)5.Set the datarate attributes on the radio nodes to match that of the datarate of the PPP links connecting them to the routers6.Configure the min frequency attributes of the radio nodes such that the transmitter frequency of one radio matches that of the receiver frequency of the other radio nodeKeep in mind that this will only provide a point-to-point radio connection, not a brodcasting radio interface.

DES Kernel->Process Modeling/Coding,Protocols->Wireless LAN,Protocols->IP