| Summary: | 碩士 === 國立中央大學 === 通訊工程研究所碩士在職專班 === 98 === Among of various home network protocols, the MoCA takes advantage of
original coxial cable wring in home. Its target is that easily buildup a high speed home
network without new wring, aned offers all 3C consumer devices to connect each
other and access to internet. From the viewpoint of MAC layer of MoCA, its access
way is different than other home network protocols, such as HomePNA and
HomePlug, which use competition access for priority base QoS and non-competition
access for parameter base QoS. Regarding to the way of competition access, it must
work with CSMA/CD and back off mechanism to avoid packet collosion occurring.
On network access, the MoCA needs a device calls “network coordinator” to allocate
channel bandwidth to all nodes according to their bandwidth requests, therefore,
theoretically,no collision takes place.
The MoCA defines two kind of QoS, one is prioritized QoS and another one is
parameterized QoS.To approach prioritized QoS, first ,the node devices have to
classify received packet in accordance with its 802.1p tag, then place it into its
belonged priority queue. Next, all nodes sends out the reservation request to network
coordinator to request channel access time. After collecting all reservation requests
from all nodes, NC will allocate bandwidth on MAP of next map cycle.
Due to that MoCA is a fully scheduling network and all network access are
central controlled by NC, the way of packet sheduling on NC is high correlative to its
network efficiency. On this thesis, we docus on the prioritized QoS on MoCA. On
scheduler design, we adopt most popular packet data scheduling technique – “round
robin and weighted fare queue” as core mechanism on NC. Regarding to each priority
quque on NC, we proposal a method names “lowest allocated bandwidth record first
out” to decide reservation elements order within the queue and use dual threshold to
control delay. In order to analysis our proposal, our simulation will collect the
throughout, packet delay and packet loss to evaluate scheduler performance. On
summary chapter, we summarize the advantages and disadvantages of our proposal as
well as prioritized QoS arrording to our simulation result.
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