Master of Research Thesis Presentation.

1. Master of Research Presentation
by
Mithileysh Sathiyanarayanan
611702
Supervisor : Dr. Kyeong Soo Kim
College of Engineering, Swansea University
October 2012

2.  The main aim of the research is to propose a new
multi-channel scheduling algorithm with tunable
transmitters and fixed receivers which provide
fairness and QoS guarantee in hybrid TDM/WDM
Optical Networks (Next-Generation Networks).

3.  To extend the Fair Queuing (FQ) frame work to
the case of multiple channels with tunable
transmitters and fixed receivers.
 To design a multi-channel scheduler using
tunable transmitters and fixed receivers.
 To avoid packet delay and improve throughput of
the system.
 To design and evaluate the performance of the
scheduler for hybrid TDM/WDM PON’s providing
fairness and QoS guarantee.
 To implement detailed simulation model for the
designed multi-channel scheduler.

4.  Scheduling is a method of harmonizing the access to
system resources among competing data flows.
 The scheduling plays an important role in achieving
high performance of the networking systems.
 Well-designed scheduling algorithms could provide
higher throughput, lower latency, and better fairness
with lower complexity in serving the packets.

5.  The scheduling has been extensively studied mainly in
the context of single-channel communication.
 The advent of wavelength division multiplexing
(WDM) technology, however, demands the extension of
this packet scheduling problem to the case of multi-
channel communication, especially with the tunable
transmitters for hybrid time division multiplexing
(TDM)/ wavelength division multiplexing (WDM)
systems.

6.  The major focus of existing work is mostly on the
throughput and delay performance of the scheduling
algorithm like in SUCCESS-HPON [1], but there is
hardly any support for fairness and QoS guarantee.
 The other focus is on the well-known DRR scheduling
algorithm [2] for single-channel case which has
advantages such as --it is simple and easy to implement,
cost-effective, provides fairness and has a complexity of
O(1).

7.  The research is mainly based on the tunable
transmitters and fixed receivers in the multi-channel
system which requires investigation in the performance
of a multi-channel deficit round-robin (MCDRR)
scheduling algorithm, which can provide fairness (in
terms of throughput) for flows with different size
packets with O(1) processing per packet.

8. Fig 1 : Block diagram of a hybrid TDM/WDM link based on tunable
transmitters and fixed receivers.

9.  The MCDRR is an extension of the DRR which takes into
account the availability of channels and tunable transmitters and
overlaps ‘rounds’ in scheduling to efficiently utilize channels
and tunable transmitters.
 The MCDRR allows multiple rounds to overlap and run in
parallel, the scheduling and the transmission of packets are not
necessarily sequential unlike the DRR.

10. Start of Round 1

11. End of Round 1

12. Start of Round 2

13. End of Round 2

14. Start of Round 3

15. End of Round 3

16. End of Round1 showing in Tunable Transmitter
End of Round2 showing in Tunable Transmitter

17. End of Round3 showing in Tunable Transmitter
Overlapping of all the three rounds in MCDRR Scheduling

20.  In Figure (2), the interframe times are exponentially
distributed with the averages of 16 mus and 48
mus for the first flow and the rest of the flows
respectively, while the frame sizes are uniformly
distributed between 64 and 1518 bytes for all the
flows.
 In Figure (3), the interframe times are exponentially
distributed with the averages of 16 mus and 32
mus for the first flow and the rest of the flows,
while the frame sizes are fixed to 1000 bytes for
the first flow and 500 bytes for the rest of the
flows.

21.  From the simulation results, we found that
the proposed MCDRR scheduling algorithm
provides nearly perfect fairness even with ill-
behaved flows for different sets of conditions
for interframe times and frame sizes.

22.  We have proposed and investigated the performance of
the MCDRR scheduling algorithm for a multichannel link
with tunable transmitters and fixed receivers, which is
based on the DRR.
 In extending the DRR to the case of multi-channel
scheduling, we try to efficiently utilize the network
resources (i.e., channels and tunable transmitters) by
overlapping rounds, while maintaining its low
complexity (i.e.,O(1)). The nearly perfect fairness
provided by the MCDRR has been demonstrated
through simulation experiments.

23.  A detailed study must be carried out about the
end-to-end performance of a network of MCDRR.
 We can try to achieve 100% throughput by
providing tight bounds.
 Establishing mathematical bounds for the
fairness and latency of the MCDRR is an
important future work and also the comparison
with other multi-channel scheduling algorithms
can be carried out.
 We can extend the present research to upstream
scheduling and using tunable receivers.

24.  [1] K. S. Kim, D. Gutierrez, F.-T. An, and L. G.
Kazovsky, “Design and performance analysis
of scheduling algorithms for WDM-PON under
SUCCESS-HPON architecture,” J. Lightw.
Technol., vol. 23, no. 11, pp.3716–3731,
Nov. 2005.
 [2] M. Shreedhar and G. Varghese, “Efficient
fair queueing using deficit round robin,”
SIGCOMM Comput. Commun. Rev., vol. 25,
no. 4, pp.231–242, 1995.

25.  Multi-Channel Deficit Round-Robin Scheduling
for Hybrid TDM/WDM Optical Networks
 Presented at FOAN-2012 Russia
 http://iathnrl.swan.ac.uk/~kks/publications/m
cdrr_foan2012.pdf

26. THANK YOU FOR
Listening !!!