Itai Novitarger & David Haloni 1. 2 ♠I♠I♠I♠Itai Novitarger & ♠D♠D♠D♠David Haloni Instructed by : Shay Auster

Itai Novitarger & David HaloniItai Novitarger & David Haloni 11


♠Itai NovitargerItai Novitarger& &

♠David HaloniDavid Haloni

Instructed by : Shay AusterInstructed by : Shay Auster


GoalsGoals赳 Design & development of a wireless TDMA Design & development of a wireless TDMA

simulation module.simulation module. Changing TDMA transmission\reception rates.Changing TDMA transmission\reception rates.赳 Creation of an algorithm performance Creation of an algorithm performance

analysis platform which includes:analysis platform which includes:I. I. Physical & MAC layers.Physical & MAC layers.

II. II. Fragmentation layer – Provides changing rates support.Fragmentation layer – Provides changing rates support.

III. III. Performance measurement tools.Performance measurement tools.

赳 OPNET simulation environment acquaintance.OPNET simulation environment acquaintance.


OPNET Work OPNET Work environmentenvironment

赳 Powerful network simulation environment.Powerful network simulation environment.

赳 Allows complex statistics collection.Allows complex statistics collection.

赳 User friendly GUI. User friendly GUI.

Design Work Design Work environmentenvironment

赳 Lots of Pencils & PapersLots of Pencils & Papers


A little about TDMAA little about TDMA赳 Time Division Multiple Access.Time Division Multiple Access.赳 Allows multiple transmitters to access a Allows multiple transmitters to access a

single radio-frequency channel without single radio-frequency channel without interference.interference.

赳 Allocates separated time slots for each Allocates separated time slots for each transmitter.transmitter.

赳 Incorporates algorithm support for multiple Incorporates algorithm support for multiple channel access.channel access.


TDMA CapabilitiesTDMA Capabilities赳 Digital data transmission.Digital data transmission.赳 Improved power consumption.Improved power consumption.赳 High transmission rates.High transmission rates.赳 Supports real time information Supports real time information

transmission (Audio\Video streaming).transmission (Audio\Video streaming).赳 Supports sophisticated QOS Algorithms.Supports sophisticated QOS Algorithms.赳 Enable reliableEnable reliable communicationcommunication between between

mobile users.mobile users.


Upper LayerUpper Layer

SourceSource

Fragmentation Fragmentation (Transmission(Transmission

))

PhysicalPhysical

LayerLayer & & MACMAC

Upper Layer Upper Layer SinkSink

Fragmentation Fragmentation (Reception)(Reception)

Node Node Modules Modules

TransmissionTransmission

QueuesQueuesReceptionReception

QueueQueue


OPNET Node ModulesOPNET Node Modules


Upper Layer SourceUpper Layer Source赳 Functions as a node source module. Functions as a node source module. 赳 Generates Data messages:Generates Data messages:

♠Poisson generation rate.Poisson generation rate.♠Uniform distributed packet sizeUniform distributed packet size

赳Functions as a destination module in the Functions as a destination module in the receiving node. receiving node.

赳Gathers & destroys re-assembled messages.Gathers & destroys re-assembled messages.

Upper Layer SinkUpper Layer Sink


Fragmentation Layer Fragmentation Layer Transmission Transmission

赳 Simulates changing transmission rates:Simulates changing transmission rates:♠Disassembles large source messages into scaled Disassembles large source messages into scaled

packets according to the current transmission packets according to the current transmission rate. rate.

♠Updates essential packets fields:Updates essential packets fields:♠External & Internal numbering.External & Internal numbering.

♠‘‘Last’ bit.Last’ bit.

♠Updates relevant statistics.Updates relevant statistics.♠Inserts packets into transmission queues Inserts packets into transmission queues

according to the current transmission rate.according to the current transmission rate.


Fragmentation LayerFragmentation Layer Transmission in Transmission in OPNETOPNET


Transmission QueuesTransmission Queues

赳A set of passive queues.A set of passive queues.

赳One queue per each possible transmission One queue per each possible transmission rate.rate.

赳Each queue is designed to accommodate Each queue is designed to accommodate packets of a designated size. packets of a designated size.

赳Performs as buffers for both Fragmentation Performs as buffers for both Fragmentation & MAC layers (DownStream).& MAC layers (DownStream).


Transmission QueuesTransmission Queuesin OPNETin OPNET


MAC & Physical layers MAC & Physical layers (1)(1)

赳 Transmit packets queued inside the Transmit packets queued inside the transmission queues.transmission queues.

赳 Based on TDMA media access control.Based on TDMA media access control.赳 Support changing transmission rates:Support changing transmission rates:

♠ Get the packets from the relevant queue Get the packets from the relevant queue according to the current transmission rate.according to the current transmission rate.

♠ Constant transmission time slot.Constant transmission time slot.


赳‘‘Listen’ to the radio network & capture Listen’ to the radio network & capture relevant packets.relevant packets.

赳Transfer packets into reception queues.Transfer packets into reception queues.

赳Update current transmission rate Update current transmission rate according to an external file. according to an external file.

MAC & Physical layers MAC & Physical layers (2)(2)


MAC & PhysicalMAC & Physicallayers in OPNETlayers in OPNET


Reception QueueReception Queue赳 A single active queue, consists of infinite A single active queue, consists of infinite

number of sub-queues.number of sub-queues.赳 Each sub-queue accommodates packets Each sub-queue accommodates packets

associated to a specific incoming message. associated to a specific incoming message. 赳 Fragmentation layer receives sub-queues Fragmentation layer receives sub-queues

status updates when packets arrive from the status updates when packets arrive from the MAC layer.MAC layer.

赳 Forwards packets accommodated inside a Forwards packets accommodated inside a specific sub-queue, in response to specific sub-queue, in response to fragmentation layer request. fragmentation layer request.

赳 Sub-queues are flushed when their TIMEOUT Sub-queues are flushed when their TIMEOUT counter expires. counter expires.


Receiver QueueReceiver Queue in OPNET in OPNET


Fragmentation Fragmentation LayerLayer Reception Reception

赳Draws all sub-queue packets according to Draws all sub-queue packets according to sub-queue updates.sub-queue updates.

赳Reassembles packets & recreates original Reassembles packets & recreates original source messages.source messages.

赳Updates relevant statistics.Updates relevant statistics.

赳Sends messages to the sink.Sends messages to the sink.


Fragmentation LayerFragmentation Layer Reception in OPNET Reception in OPNET


Packet StructurePacket Structure

Data Data – (modified length)– (modified length)

LenLenDestDestSourceSource chksumchksum

AckAck

IDIDInternalInternalExternalExternal paddingpadding

LastLast


赳Simulation StatisticsSimulation Statistics::♠Fragmentation Disassemble TimeFragmentation Disassemble Time – –

Based on the average number of packets divided from a Based on the average number of packets divided from a single message, according to the transmitter point of single message, according to the transmitter point of view.view.

♠Fragmentation Reassemble TimeFragmentation Reassemble Time – – Based on the average number of packets associated to Based on the average number of packets associated to

a single message, according to the receiver point of a single message, according to the receiver point of view.view.

♠Fragmentation RateFragmentation Rate – – Based on the division between the number of messages Based on the division between the number of messages

which has been splited to those which hasn’t.which has been splited to those which hasn’t.

Performance Performance MeasurementMeasurement


Statistics ResultsStatistics ResultsDisassemble TimeDisassemble Time Reassemble TimeReassemble Time


Statistics ResultsStatistics Results fragmentation ratefragmentation rate


Future DevelopmentsFuture Developments

赳Automated Transmission rates Automated Transmission rates algorithm.algorithm.

♠Currently: rates change according to an input Currently: rates change according to an input file.file.

赳Finite\Infinite storing queues.Finite\Infinite storing queues.♠Currently: Infinite queues.Currently: Infinite queues.

赳Priority queues.Priority queues.♠A lot of effort was invested in order to A lot of effort was invested in order to

support convenient future expansions.support convenient future expansions.


Supplemental Supplemental InformationInformation

赳 Website:Website:http://www.Comnet.technion.ac.il/~cn6s02/index.htmhttp://www.Comnet.technion.ac.il/~cn6s02/index.htm


QuestionsQuestions??? ???


Documents

Itai Novitarger & David Haloni 1. 2 ♠I♠I♠I♠Itai Novitarger & ♠D♠D♠D♠David Haloni Instructed by : Shay Auster