3 Goals 赳D赳D赳D赳Design & development of a wireless TDMA simulation module. CCCChanging TDMA transmission\reception rates. 赳C赳C赳C赳Creation of an algorithm performance analysis platform which includes: I. Physical & MAC layers. II. Fragmentation layer – Provides changing rates support. III. Performance measurement tools. 赳O赳O赳O赳OPNET simulation environment acquaintance.
4 OPNET Work environment 赳 P赳 P赳 P赳 Powerful network simulation environment. 赳 A赳 A赳 A赳 Allows complex statistics collection. 赳 U赳 U赳 U赳 User friendly GUI. Design Work environment 赳 L赳 L赳 L赳 Lots of Pencils & Papers
5 A little about TDMA 赳 Time Division Multiple Access. 赳 Allows multiple transmitters to access a single radio-frequency channel without interference. 赳 Allocates separated time slots for each transmitter. 赳 Incorporates algorithm support for multiple channel access.
Itai Novitarger & David Haloni6 TDMA Capabilities 赳 Digital data transmission. 赳 Improved power consumption. 赳 High transmission rates. 赳 Supports real time information transmission (Audio\Video streaming). 赳 Supports sophisticated QOS Algorithms. 赳 Enable reliable communication between mobile users.
Itai Novitarger & David Haloni8 OPNET Node Modules
9 Upper Layer Source 赳 Functions as a node source module. 赳 Generates Data messages: ♠ Poisson generation rate. ♠ Uniform distributed packet size 赳 Functions as a destination module in the receiving node. 赳 Gathers & destroys re-assembled messages. Upper Layer Sink
Itai Novitarger & David Haloni10 Fragmentation Layer Transmission 赳S赳S赳S赳Simulates changing transmission rates: ♠D♠D♠D♠Disassembles large source messages into scaled packets according to the current transmission rate. ♠U♠U♠U♠Updates essential packets fields: ♠E♠E♠E♠External & Internal numbering. ♠‘♠‘♠‘♠‘Last’ bit. ♠U♠U♠U♠Updates relevant statistics. ♠I♠I♠I♠Inserts packets into transmission queues according to the current transmission rate.
Itai Novitarger & David Haloni11 Fragmentation Layer Transmission in OPNET Fragmentation Layer Transmission in OPNET
Itai Novitarger & David Haloni12 Transmission Queues 赳 A set of passive queues. 赳 One queue per each possible transmission rate. 赳 Each queue is designed to accommodate packets of a designated size. 赳 Performs as buffers for both Fragmentation & MAC layers (DownStream).
Itai Novitarger & David Haloni13 Transmission Queues in OPNET
Itai Novitarger & David Haloni14 MAC & Physical layers (1) 赳 Transmit packets queued inside the transmission queues. 赳 Based on TDMA media access control. 赳 Support changing transmission rates: ♠ Get the packets from the relevant queue according to the current transmission rate. ♠ Constant transmission time slot.
Itai Novitarger & David Haloni15 赳 ‘ Listen ’ to the radio network & capture relevant packets. 赳 Transfer packets into reception queues. 赳 Update current transmission rate according to an external file. MAC & Physical layers (2)
Itai Novitarger & David Haloni16 MAC & Physical layers in OPNET MAC & Physical layers in OPNET
Itai Novitarger & David Haloni17 Reception Queue 赳 A single active queue, consists of infinite number of sub-queues. 赳 Each sub-queue accommodates packets associated to a specific incoming message. 赳 Fragmentation layer receives sub-queues status updates when packets arrive from the MAC layer. 赳 Forwards packets accommodated inside a specific sub-queue, in response to fragmentation layer request. 赳 Sub-queues are flushed when their TIMEOUT counter expires.
Itai Novitarger & David Haloni18 Receiver Queue in OPNET
Itai Novitarger & David Haloni19 Fragmentation Layer Reception 赳D赳D赳D赳Draws all sub-queue packets according to sub- queue updates. 赳R赳R赳R赳Reassembles packets & recreates original source messages. 赳U赳U赳U赳Updates relevant statistics. 赳S赳S赳S赳Sends messages to the sink.
Itai Novitarger & David Haloni20 Fragmentation Layer Reception in OPNET Fragmentation Layer Reception in OPNET
Itai Novitarger & David Haloni21 Packet Structure Data – (modified length) LenDestSourcechksumAck IDInternalExternalpadding Last
Itai Novitarger & David Haloni22 赳 Simulation Statistics : ♠ Fragmentation Disassemble Time – Based on the average number of packets divided from a single message, according to the transmitter point of view. ♠ Fragmentation Reassemble Time – Based on the average number of packets associated to a single message, according to the receiver point of view. ♠ Fragmentation Rate – Based on the division between the number of messages which has been splited to those which hasn ’ t. Performance Measurement
Itai Novitarger & David Haloni23 Statistics Results Statistics Results Disassemble Time Reassemble Time
Itai Novitarger & David Haloni25 Future Developments 赳 Automated Transmission rates algorithm. ♠ Currently: rates change according to an input file. 赳 Finite\Infinite storing queues. ♠ Currently: Infinite queues. 赳 Priority queues. ♠ A lot of effort was invested in order to support convenient future expansions.
Itai Novitarger & David Haloni26 Supplemental Information 赳 Website: http://www.Comnet.technion.ac.il/~cn6s02/index.htm