a combinational media access protocol for multicast traffic in single-hop wdm lans student : t.h lin...
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A combinational media access protocol for multicast traffic in single-hop WDM lans
Student : T.H LinTeacher : H.T Wu
Date : 7.28
Outline Introduction The architecture of single-hop
WDM networks Protocol The combinational multicast
schedule (CMS) Simulation Results Conclusions
Introduction
Using reservation-based protocol Partitioning multicast group
Using pre-allocation-based protocol
The architecture of single-hop WDM networks The Passive Star Coupler to connect N
nodes. PSC is an N * N broadcast-and select
device interconnected through the optical fibers.
Each node contains one pair of FT-FR to collect the status of multicast traffic, and one pair of FT-TR to access data channel.
The architecture of single-hop WDM networks
The network is packet-switched with fix-size packets and operates in a slot mode.
The buffer at each node is assumed toN-1 queues, one dedicated queue and to allocate one queue for multicast transmission.
The architecture of single-hop WDM networks
Collision The arbitration procedure can avoid.
Destination conflict The receiver wavelength allocation map.
Multicast Traffic Each multicast p
acket has its own value of M.
M>Md perform multicast transmission.
M<Md the packet is treated as the unicast packet.
Protocol
The combinational media access protocol combines the unicast-based protocol and the Multicast Slot Reservation in the FT-TR architecture.
The Unicast-Based Protocol Each node is assigned Ω slots per
cycle and idle for the remaining N- Ω slots.
The Multicast Slot Reservation
IF M < Md, the MSR replicates the packet and transmits the replicated packets from the multicast source node to members of the multicast group individually.
IF M > Md, the MSR makes the reservation of the home channel of the multicast source node.
The Arbitration Procedure
The request for multicast transmission has the higher priority to reserve the home channel and can be issued at any time slot.
The request for unicast transmission has the lower priority to reserve the channel and be issued according to the unicast protocol.
The combinational multicast schedule (CMS) After receiving the control packet, all
nodes execute the Combinational Multicast Schedule (CMS) at each time slot.
Simulation result The parameters are N=50 network
nodes , Ω= 25 wavelengths. The buffer size of the dedicated queue
per node is 100. |G| and S are the normal distribution
with mean of 5 nodes The nodes in the multicast group G are
randomly chosen from the uniform distribution [0,N-1]
Packet generation follows the Poisson arrival process with parameter q = 0.1.
The multicast packet with prob p and the unicast packet with prob 1-p
Md = 0 means the separate scheduling of unicast and multicast traffic.
Md = 100 means the scheduling of multicast traffic as unicast traffic.
Packet delay The number of time slots elapsed from the
slot entering the network to the slot leaving the network.
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