Modeler Day2 (reupload)

8/12/2019 Modeler Day2 (reupload)

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OPNET Modeler

Day 2


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copyright 2001 OPNET Technologies, Inc.

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Course Outline

Events and Event List Concepts

Process Modeling Process Modeling Lab Collecting Scalar Statistics Radio Modeling


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Events and

Event List Concepts


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Agenda

Event-driven Simulation

Event List and the Simulation Time Clock

Simulation Kernel

Interrupts

Processes and Interrupts

Event List Example


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Event-Driven Simulation

Events are specific activities that occur at a certain time

OPNET simulations are event-driven

Simulation time advances when an event occurs

A different method might be to sample at regular intervals Disadvantages:

Accuracy of results is limited by the sampling resolution Simulation is inefficient if nothing happens for long periods



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Time Event Type Module0.0 Initialize src.gen0.0 Initialize src.rte4.3 Timer expires src.gen

4.3 Packet arrives src.rte

Head

Event List Concepts

Single global event list

Shared simulation time clock

Events scheduled in time order

Event removed from event list when it completes



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The Simulation Kernel

Simulation Kernel (SK) manages the event list

SK delivers each event, in sequence, to the appropriate module

SK receives requests from processes and inserts new events in the event list



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Event Generation and Cancellation

Events can be generated in several ways

BEGSIM/ENDSIM interrupts Self interrupts Packet arrivals (STRM interrupts) Writing to a statwire (STAT interrupts)

Events can be cancelled before they occur



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Interrupts

First event in the event list becomes an interrupt

Delivered by the Simulation Kernel to the designated module

Data associated with the event can be obtained by the module

Processors and queues can have BEGSIM interrupts



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How Does the Event List Work?

New event reaches head ofevent list, which causes

Simulation Kernel to deliveran interrupt to the appropriate

module

Simulation Kernel regainscontrol from module

Process within themodule gains control

and processesinterrupt

Simulation Kerneldeletes event fromevent list, allowingnew event to reach

head of list



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Event List Implementation

The Simulation Kernel uses an efficient proprietary algorithm to maintainthe event list

Event times are expressed as double-precision, floating-point numbers andare used to keep the event list sorted

0.01234 56789 11111 11

0.01234 56789 11111 22

0.01234 56789 11111 33

0.01234 56789 11111 44

0.01234 56789 11111 55

0.01234 56789 11111 66

0.01234 56789 11111 77

Suppose that this interrupt triggers an event to occur at0.01234 56789 11111 75.

The Simulation Kernel minimizes the time required to place this event at the correct place on the list.


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Delivery of Interrupts

When an interrupt is delivered to a module, control passes from theSimulation Kernel to the module

If the module is a queue or processor, the interrupt is delivered to the process running within the module

Other modules have default behaviors


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Event List Concepts Reviewed

Events must exist in the event list at the start of a simulation

A processor or queue module has the begsim interrupt attribute enabled

An event list typically has a few events each event may schedule otherevents

The event list is always growing and shrinking

An event is pending until executed

A pending event can be cancelled


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Forced States

Forced (green) and unforced (red)states differ significantly inexecution timing

In a forced state, the process: Invokes the enter executives

Invokes the exit executives Evaluates all condition statements If exactly one condition statement

evaluates to true, the transition istraversed to the next state

OPNET convention: code in enterexecs only

Transition to next state


Forced (green) states

Enter execsinvoked

No blocking or waiting

Exit execsinvoked

Enter execsinvoked

Exit execsinvoked

No blocking or waiting


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Unforced States

In an unforced state, the process:

Invokes the enter executives Places a marker at the middle ofthe state

Releases control to the SimulationKernel and becomes idle

Resumes at the marker and processes the exit execs when nextinvoked

Start of invocation

End of invocation

Unforced (red) states


Blocking, waitingfor invocation

Exit execs processedwhen invocation occurs

Enter execsinvoked

Next

invocationstarts here

Blocking, wait fornext invocation


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Transitions Between States

After completing the exit executives, the process evaluates theconditions for all transitions from the state

One and only one condition statement must evaluate to true

The single true transition is taken to the next state

A transition with condition = default is true if and only if no otherconditions are true

A transition with no condition set is termed unconditional and isalways true


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How a Process Handles an Interrupt

Flow diagram showing how a process handles an interrupt:

(except the initial interrupt)

Implementexit execs

Set marker; block and wait

for interrupt

Receiveinterrupt

Evaluateconditionstatements

Red state? Yes

No

Follow transitionto next state Implement enter

execs

Find marker


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Process Model Example

Model with three forced states and one unforced state:

3. Transition occurs. 6. Transition occurs.

2. Exit execs invoked immediately. Transitioncondition (pk_count == 0) evaluates totrue. 5. Exit execs invoked immediately.

8. Marker is placed and process stops here.

7. Enter execs invoked.4. Enter execs invoked.1. Initial interrupt delivered and the enterexecs invoked.


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The Simulation Kernel and Processes

Control passes between the Simulation Kernel (SK) and multiple processes(pr1, pr2 , etc.), as described below:

Description In control Idle Read first event on event list. Deliver to appropriate process ( pr1 ). SK All processes

Invoke enter and exit execs of initial state ( forced1 ) . Evaluate pr1 SK; other processescondition statements and transition to next state ( forced2 ).Invoke enter and exit execs of forced2 . Transition to next state ( unforced ).Invoke enter execs of next state ( unforced ). Release control to SK. Become idle.

Remove first event from event list. Advance next event to SK All processeshead of list. Deliver interrupt to pr2.

Invoke enter and exit execs of initial state (this process model is not shown). pr2 SK ; other processesEvaluate condition statements and transition to next state


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Event List Example

Consider this model:

Network model

Node model

Node model

Node model: src

Node model: dest1

Network model


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The BEGSIM Interrupt

BEGSIM is an interrupt that occurs at simulation time 0.0, before any othertype of interrupt

A BEGSIM interrupt usually initializes a module and schedules futureevents

Any processor or queue can have its begsim intrpt attribute enabled,resulting in an event being placed on the event list for time 0


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Event List Example (cont.)

The begsim intrpt attribute for modules src.gen and src.queue is enabled; this places two events in the event list

Time Event Type Module0.0 BEGSIM src.gen0.0 BEGSIM src.queue

Node model


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Processing the First Interrupt

Consider the process model specified by the src.gen module

Node model: src

Process model: gen


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h ( )


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Processing the First Interrupt in Process gen (cont.)

Process model

Process model: gen

P i h Fi I i P ( )


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Because Init is a forced (green) state, process immediately invokes andcompletes the exit execs.

Process evaluates all condition statements. This state has only onedeparting transition which evaluates to true.

Process transitions to Wait state.


P i h Fi I i P ( )


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Process model

Process invokes and completes the enter execs of Wait .


P i th Fi t I t t i P ( t )


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Line 9 of the enter execsschedules a self interrupt usinga KP. This adds an event tothe event list.

Process places a marker at the

middle of Wait .

Process becomes idle.

Time Event Type Module0.0 BEGSIM src.gen0.0 BEGSIM src.queue4.3 SELF src.gen

Marker



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Processing the Next Interrupt at module src gen


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Processing the Next Interrupt at module src.gen

Simulation Kernel removes the previous event and advances the nextevent to the head of the event list. The simulation time becomes 4.3

seconds.

Simulation Kernel delivers the SELF interrupt to the gen process. The process resumes at the marker in the middle of Wait .

Process invokes and completes the exit execs of Wait .

Time Event Type Module 4.3 SELF src.gen


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Continuing the Process at gen (cont )


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Continuing the Process at gen (cont.)

Process transitions to Send . Process invokes the enter execs of Send and calls op_pk_send( ) to

send a packet. This results in an event of type STRM being placedon the event list.

Time Event Type Module 4.3 SELF src.gen4.3 STRM src.queue

Continuing the Process at gen (cont )


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Continuing the Process at gen (cont.)

Process immediately invokes and completes the exit execs, becauseSend is a forced (green) state.

Process evaluates all possible transitions. One evaluates to true.

Process transitions to Wait

Process invokes enter execs of Wait , schedules another SELF interruptin the event list and becomes idle.

Simulation Kernel takes control and processes the next event in the list.

Simulation Termination


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Simulations terminate in one of four ways: The event list is emptied Simulation attribute duration expires A process calls for termination, using the KP op_sim_end() A fatal error occurs

How Does Time Advance?


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How Does Time Advance?

Simulation time advances only when an event with a later time is processed from the event list

No simulation time occurs during the execution of a process

No time elapses during transitions between states

A process model must always have an unforced (red) state so time canadvance Avoid endless looping between

forced (green) states

Events and Event List Concepts: Summary


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Events and Event List Concepts: Summary

Forced and unforced states execute differently

Any processor or queue can have the attribute begsim intrpt enabled,scheduling an event for time 0.0

Control passes dynamically between the Simulation Kernel and individual

processes


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Process Modeling

Agenda


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g

Process models

Process Editor State transitions Executive blocks

Kernel Procedures

Examine acb_fifo

Lab: Modify a process model

Process Models


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Process models represent algorithms Communications protocols and algorithms Shared-resource managers Queuing disciplines Specialized traffic generators Statistic-collection mechanisms Control Processes

Process Editor provides the features for creating process models

Process Editor


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1. Create state2. Create transition3. Set initial state4. Edit state variable5. Edit temporary variable6. Edit header block7. Edit function block8. Edit diagnostic block9. Edit termination block10. Compile process model

1 2 3 4 5 6 7 8 9 10

Toolbar Buttons:

State Transitions


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Transitions connect states Conditional

Unconditional Transition executive

Exactly one condition must evaluate to true If the condition statement (x == y) is true, the transition executive (Reset_Timers)

is invoked

Transition executiveCondition statement

State Executive Blocks


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Each state has two executive blocks Enter executives are invoked upon entering a state

Exit executives are invoked before exiting a state

Introduction to Kernel Procedures


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Pre-written functions for difficult, tedious, or common operations

KPs free users from addressing memory management, data structure,handling event processing, etc.

KPs focus on communication modeling

All KPs begin with prefix op_

Common Kernel Procedures


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Packet Package: op_pk_create ()op_pk_create_fmt ()op_pk_copy ()op_pk_get ()op_pk_total_size_get ()op_pk_nfd_set ()op_pk_nfd_get ()op_pk_send ()op_pk_send_delayed ()

op_pk_destroy ()

Subq Package :op_subq_pk_insert ()op_subq_pk_remove ()

Interrupt Package:op_intrpt_schedule_self ()

op_intrpt_type ()op_intrpt_strm ()op_intrpt_code ()

Simulation andEvent Packages: op_ev_cancel ()

op_sim_time ()

ID, Topo and InternalModel Access Packages:op_id_self ()op_topo_parent ()op_topo_child ()

op_ima_obj_attr_get ()

Distribution Package :op_dist_load ()op_dist_outcome ()

Naming convention for Kernel Procedures -

op__

Kernel Procedures Help


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From the Help menu, select Online Documentation and refer to theSimulation Kernel manual

Press + to view Essential Kernel Procedures Press + + to view All Kernel Procedures

Each KP is described in several paragraphs. Review at least theAbstract, Syntax, and ReturnValue fields.

KP Name

Syntax

Return Value

Example

The manual is divided into sections by KP family (such as Anim, Dist,Sim, Stat) and sorted by KP namewithin each section.

Details

Purpose

Errors

Reference

Abstract

Proto- C


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State transition diagrams C programming language Library of OPNET Kernel Procedures (KPs) State variables (private to each process) Temporary variables

Example Process Model: acb_fifo


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Queue process model

Characteristics Has a service rate, in bits/sec FIFO queue

Active Concentrating Bit-oriented First In First Out queue Active: Has a processor Concentrating: Will take from many input streams and output to only one

stream Bit-oriented: Delay is based on number of bits processed

acb_fifo: State Overview


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Purpose of each state init initializes state variables arrival queues packets svc_start calculates when the packet can be sent svc_compl sends the packet idle is the wait state

acb_fifo: Idle state


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Packet arrival Packet is queued in arrival To svc_start if not busy Back to idle if busy

Service completion Sends queued packet in svc_compl

To svc_start if queue nonempty Back to idle if queue busy

acb_fifo: arrival State


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Gets the incoming packet

Tries to queue packet

Destroys packet ifqueue is full

acb_fifo: svc_start State


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Begins servicing the packet Schedules an interrupt for service completion

acb_fifo: svc_compl State


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Sends the serviced packet Receiving module will get control immediately


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Process Modeling: Summary


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Process models Finite state machines

Proto-C acb_fifo

Kernel Procedures


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Process Modeling Lab

Lab Description


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This lab uses the project bank_net , to model changes in the transaction rateand measure the effects of those changes

Create modified sink process model to compute ETE delay Get the packet Obtain the creation time Write out its ETE delay as a global statistic Destroy the packet

Incorporate new sink process model into existing node model

Create ETE delay statistic probe

Run simulation

Filter the View Results graphs to answer questions


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CollectingScalar Statistics

Agenda


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Conceptual goals: Creation of an attribute of a

process model Collect scalar statistics

Tool goals: View scalar analysis results

Creating an Attribute for the Process Model


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4

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Scalar Statistics


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A scalar statistic is a single value representing a statistic computed over aninterval, typically the entire simulation. A scalar statistic:

Allows for parametric studies. Must be plotted versus another scalar. Shows the effect that making a change has on certain output parameters. Is usually a summary of some aspect of a networks behavior.


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Scalar Statistics


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A scalar statistic is a single value representing a statistic computed over aninterval, typically the entire simulation (example: average end-to-end delay

for all received packets in a simulation).

Scalar statistics: Must be plotted versus

another scalar statistic

Allows for parametric studies Requires many simulation

runs because each run produces only one data point

Collecting Scalar Statistics


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Use any of three methodsto collect a scalar

statistic: A statistic probe created

in the Probe Editor (as below)

An attribute probe

The KPop_stat_scalar_write(scstat_name, value)

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1

3

Using the Simulation Sequence Editor


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In order to collect scalarstatistics, a scalar file must

be specified. This output file will record

the scalar simulationstatistics.

There is only one data point per simulation run.

The simulation programappends data to an existingfile, allowing for multi-simulation parametricstudies.

Using the Simulation Sequence Editor


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By promoting an objectsattribute to the simulation

level, multiple values forthat attribute can be set. By left-clicking on a blank

under Attribute the usercan add a currently

promoted attribute. After adding the attribute to

the table, the user can selectmultiple values for thatstatistic, and simulations

will run with each value.

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2 3

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Plotting a Scalar Panel


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Understanding the Problem and Questions


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Modify the Bank_net project to include a custom generator that has anattribute transaction_rate , the transaction rate in transactions

per second.

Answer the following questions: Are your results the same with this customized generator as with the ideal

generator? Hint: run the simulation with the same probe file as before.

Verify that results are the same. What is the maximum generation rate such that the average ETE delay for

all transactions is less than 5 seconds? Hint: run multiple simulations withdifferent transaction rates, collecting scalar data.

Creating a Custom Generator Procedure


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1. Determine functionality of the process model.2. Determine necessary states.

3. Create transitions between states. Write condition statements andcreate macros for them.

4. Determine state variables.5. Use C code and KPs to implement each states enter and exit

executives.6. Declare variables.7. Compile the process model.


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Useful KPs for This Model

k d( k d ) f d k h h


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op_pk_send (pkptr , outstrm_index) forwards a packet through anoutput packet stream and schedules its arrival at a destination module.

cur rent_ti me = op_sim_time () obtains the current simulation time. object_id = op_id_self () obtains the value of the surrounding

processor or queue. op_ima_obj_attr _get (objid, attr_name, value_ptr) obtains the value

of an attribute for the specified object.

Lab Approach and HintsRemember the questions we are trying to answer:


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Are your results the same with this customized generator as with the ideal generator?

What is the maximum generation rate such that the average ETE delay for all transactions is less than 5 seconds?

1. Create a new generator process model.a. Create an attribute of the process named transaction_rate .

b. Place states and transitions.c. Define code in executive blocks.d. Compile the process model.

NOTE: if you do not want to create this model, it is available as model "mdlr_lab12_gen".Examine it to see how it was implemented.

2. Modify the node model to include the new generator process (use a processor instead of anideal generator).

3. Modify probe file to capture the scalar statistic ETE delay by adding a global statistic probe.

4. Run multiple simulations and view output in the Analysis Tool. To ensure convergence,you may want to run with a duration longer than 1000 sec (however, the simulations willtake longer to complete).

Lab Results


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If you finish early, try the Advanced Lab

Modify the sink process to collect the total number of bits that it receives


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Modify the sink process to collect the total number of bits that it receives(use op_pk_total_size_get () ). At the end of the simulation, write out the

the statistic: "Global Bit Throughput" = total bits received / total simulation time

Add an additional receiver to the PHIL node model that also sends packetsto the sink module.

Add an additional New York node that sends bank transactions to PHIL.

Plot the scalar panel ETE Delay vs. Global Bit Throughput for a variety oftransaction rates.


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Radio Modeling

Agenda

C l G l T l G l


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Conceptual Goals Introduction to radio modeling

Introduction to TransceiverPipeline Stages

Mobile/Satellite Nodes Custom Packets Custom Antennas

Link Models Custom PDFs

Tool Goals Define Trajectory

Packet Format Editor Link Model Editor Antenna Pattern Editor PDF Editor

Radio Modeling

Modeler / Radio allows models to utilize


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Modeler / Radio allows models to utilizemobile nodes and mobile subnets using

dynamic RF links.

Node and subnet positions are updated (lazyevaluation) based on user specifications suchas time step, altitude and a defined path that is

anchored on absolute or relative coordinates.

Radio transceivers must be used that employ a14 stage link budget model called theTransceiver Pipeline

Radio Modeling

Radio is a broadcast technology and depends on dynamically changing


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Radio is a broadcast technology and depends on dynamically changing parameters. The simulation must evaluate the possible connectivity

between a transmitter channel and every receiver channel for eachtransmission.

The network level characteristics factored into these calculations are thelocations of the source and destination nodes, the distance between the

nodes, and the direction the radio signal travels from the source node tothe destination node.

If the nodes are mobile or satellite nodes, these position-related parametersmay change during simulation.


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Transceiver Pipeline

Models the transmission of packets across a communications channel (link)


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p ( ) Implements the physical layer characteristics

Divided into multiple stages , each modeling a particular aspect of thechannel

Determines whether or not a packet can be received at the links destination

S1 S2 S3 S4

Transmitter Receiver

Each stage models an aspect ofthe links behavior

Radio Transceiver Attributes for Specifying Pipeline Stages


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8 Stages (6-13) Associatedwith Radio Receiver

6 Stages (0-5) Associatedwith Radio Transmitter

Receiver GroupTransmission DelayLink Closure (LOS)Channel MatchTx Antenna GainPropagation Delay

Rx Antenna GainReceived PowerBackground NoiseInterference NoiseSignal-to-Noise RatioBit Error RateError AllocationError Correction

Radio Transmitter Radio Receiver

Radio Transmitter and Receiver Attributes

Modulation - name of modulation table used to look up the bit error


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prate (BER) as a function of effective signal to noise ratio

Channel - specifies the number and attributes of the channels in thetransceiver Noise figure - represents the effect of thermal noise on radio

transmission (receiver only) Ecc threshold (err/bits) - specifies the highest proportion of bit

errors allowed in a packet in order for the packet to be accepted by areceiver (receiver only)

... model - these attributes specify the various Transceiver PipelineStage models used

Radio Channel Attributes Data rate (bps) - rate at which data may be transmitted or received


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Packet formats - determines the types of packets a channel cantransmit or receive

Bandwidth (KHz) - specifies bandwidth of channel Min frequency (MHz) - specifies the base frequency of the channel Spreading code - used to specify a user-assigned code for the

channel Power (W) - transmission power of packets transmitted through this

channel (transmitter only)


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Mobile Node Trajectories

A trajectory is the path a mobile node moves along during simulation


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Trajectories can be created using the Define Trajectory selection in

the Network pull down menu. During simulation, the mobile node follows the trajectory by

traveling in a straight line from one defined position to the next. Once the simulation time exceeds the last specified time in the

trajectory file, the mobile node remains at its final position.

Defining a Trajectory1. Choose Define Trajectory

from Network pull downmenu


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Mobile nodes support an attribute called trajectory which specifies the nameof an ASCII text file defining the path of the mobile node during thesimulation.

2. Set the Trajectoryattributes to the desiredvalues.

menu

3. Click on Define Path.

5. Left-click in the work space todefine intermediate positions for themobile node.

4. Left-click at somelocation in the ProjectEditor to begin thetrajectory.

Defining a Trajectory Continued6. Define Trajectory

Segment Information


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8. Click on complete tofinish the trajectorycreation process.

7. Left-click in the work space to

define more intermediate positionsfor the mobile node.

9. Type in a trajectoryname. Click OK tosave the trajectory.

Satellite Nodes

Satellite nodes model network elements in orbit around the earth, such as


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satellites and spacecraft

Like mobile nodes, satellite nodes cannot be connected by point-to-pointand bus links because they change positions during a simulation Satellite nodes change position based on an assigned orbit or by direct

changes to the nodes position attributes.


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Lab Description

This lab will model a mobile paging system.


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Parameters: Telephones initiate pages addressed to a specific mobile pager The pages are relayed through a central base station A radio tower broadcasts the pages If the appropriate mobile pager receives the page, an ack is transmitted back to

the radio tower The radio tower relays the ack back to the base station and a successful page

statistic is recorded

Lab : Overview Create the acknowledgement and page packet formats


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Create the necessary antenna pattern, PDF, and link parameter models

Use the provided node models and the newly created parameter models to build the mobile paging network

Configure the radio transmitters and receivers

Create trajectories for the mobile pagers

Choose results, run the simulation, and view the results

Lab : Node Specifications

Telephone Node Specification


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Generates pages based on a custom PDF Determines destination of page based on a custom PDF Encapsulates an ack in the page Sends the pages on the single output port to the base station

Lab : Node Specifications (cont.)

Base Station SpecificationR i f i h i


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Receives pages on one of eight input ports

Receives acks on one input port (paired with the output port) and records the Percentage of Successful Pages (i.e., the number of acks received/ pages sent)

Radio Tower Specification Receives pages from the Base Station via an input port and broadcasts them to

the mobiles Receives acks from the mobiles and forwards them to the Base Station via an

output port


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Lab : Create Packet Formats

Open the Packet Format Editor C t k k t f t t i i 2 fi ld


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Create ack packet format containing 2 fields

Source Node (64 bits) Destination Node (64 bits)

Save as _ack_packet

Lab : Create Signal Packet Formats Open the Packet Format Editor Create page packet format containing 3 fields


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Source Node (64 bits)

Destination Node (64 bits) Encapsulated ack packet

Be sure to name the encapsulated packet field Ack Packet as the process model in the pager that will send the acknowledgement to the base station is written to look for that namein the received packet.

Save as _page_packet

Lab : Create Antenna Pattern1

2


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Create an antenna pattern for theradio tower. Number of phi planes = 10 Phi planes 90 to 162 degrees =

10 db Phi plane 72 degrees = -5 db

Save as _page_ant

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Lab : Create Link Model Create a link model that supports the recently created packets and that

represents a 16,384 bits/sec link.


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Select File , New , Link Model . Configure the link:

Link types supported: ptsimpand ptdup

Attributes = Values packet formats = ack_packet and

page_packet data rate = 16,384 bits/sec ecc model = dpt_ecc error model = dpt_error propdel model = dpt_propdel txdel model = dpt_txdel

Save as _page_link

Lab : Create Destination PDF Create Page Destination PDF Select File New PDF Editor


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Select File, New, PDF Editor

Determines which mobile pager is the destination The mobile pagers receive pages according to the following distribution:

Mobile 0: 50% Mobile 1: 15% Mobile 2: 25% Mobile 3: 10%

Use Add Impulse action button

Normalize PDF

Save As:

_page_dest_pdf


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Lab : Node Descriptions

In the interest of time, we (OPNET) have created all the nodes required forthis lab based on the specifications outlined at the beginning of this


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p g gchapter.

The next several slides focus on discussing the approach and logic thatwent into the development of the nodes and the process models.

Although the students will not have time in this course to develop thesenodes themselves, we (OPNET) encourage everyone in the class to attemptto build these models at a later date as a good skill-building exercise.

Lab : Paging Network Model Example

Open the project page_net


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Lab : Telephone Node Model Description

Added an Ideal Generator to generate page packets with the Page Interarrival PDF [Note - We used a PDF similar to the one built earlier in


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this lab.] Created a Source ID attribute to determine the origin of the page Created a process model that will set the fields of the page packet and

encapsulate an ack packet

Lab : Base Station Node Model Description

Added 8 receivers for incoming telephone lines Added 1 transceiver pair for communication with the radio tower


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p

Created a process model that will forward pages to the radio tower, receiveacks, and record the Percentage of Successful Pages


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Lab : Mobile Node Model Description Created a process model with a custom attribute Mobile ID. This process

compares the Destination ID of the packet with Mobile ID andd l t d t th k if th l


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decapsulates and returns the ack if they are equal.

Configured the transceivers to receive pages and transmit acks onfrequencies matching the towers

Configured the antenna module to use an isotropic antenna


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Lab : Viewing the Results

Under the Results pull -down menu, select View Results and thenunder Global Statistics view % of Packets Successfully Transmitted .


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Lab : Added Challenge

If you have additional time, try any one or more of the following Modify the model to include 4 additional telephones


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Modify the model to include 4 additional pagers with pages evenly distributedamong all 8

Modify the model to include another base station that shares the same radiotower (Hint: Modify the ack packet format)

The added challenges are not dependent on one another

Radio Features

TMM: (Terrain Modeling Module) The Terrain Modeling Module allows users to take into account terrain and

i l ff h d li i l k


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environmental effects when modeling wireless networks. With TMM, the user can import elevation maps that contain terrain data. Supported map formats are DTED and DEM. TMM also allows the user to select and compare signal loss from various

propagation models.

Simulation Efficiencies DRG

Dynamic Receiver Group

Parallel Processing

Lab: Using TMM

Switch to the scenario called TMM


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Lab: Viewing a Terrain Profile Using the Terrain Profile, you can view signal strength loss from a

transmitter to a receiver.


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Lab: Running a Simulation with TMM Select Configure Simulation. Check the box entitled, Use TMM.


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Lab: Viewing Results of TMM Under the Results pull -down menu, select View Results and then

under Global Statistics view % of Packets Successfully Transmitted .


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Summary Radio models depend on dynamically changing parameters, which the

simulation evaluates to determine the possible connectivity between allradio transmitters and receivers


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radio transmitters and receivers.

Modeler provides the user the ability to simulate the movement of mobilenodes along trajectories and satellite nodes in orbit.

The antenna, PDF, link and packet editors further expands the userscapability to define and customize parameters that affect the behavior ofthe model.

Modeler Day2 (reupload)

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Transcript of Modeler Day2 (reupload)