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|Title: ||Bandwidth allocation and channel assignment in WiMax mesh networks|
|Other Titles: ||WiMax mesh wang luo dai kuan diao du yu xin dao fen pei wen ti de yan jiu|
WiMax mesh 網絡帶寬調度與信道分配問題的研究
|Authors: ||Du, Peng (杜鵬)|
|Department: ||Department of Computer Science|
|Degree: ||Doctor of Philosophy|
|Issue Date: ||2009|
|Publisher: ||City University of Hong Kong|
|Subjects: ||Broadband communication systems.|
Wireless communication systems.
IEEE 802.16 (Standard)
|Notes: ||CityU Call Number: TK5103.2 .D8 2009|
viii, 108 leaves : ill. 30 cm.
Thesis (Ph.D.)--City University of Hong Kong, 2009.
Includes bibliographical references (leaves 100-108)
|Abstract: ||World Interoperability for Microwave Access (WiMax) is one of the leading
technologies in the context of Broadband Wireless Access (BWA). The PHY and
MAC layer specifications of WiMax networks are defined by the IEEE standard
802.16-2004. According to this standard, WiMax systems can work in
Point-to-Multipoint (PMP) mode or mesh mode. However, this standard does not
specify the MAC layer bandwidth allocation and channel assignment algorithms
for the mesh mode, which is decisive to the system performance in terms of
throughput and quality of service. We investigate these issues in this thesis.
As specified in IEEE 802.16-2004, time slot allocation for end-to-end traffic
flow in WiMax mesh networks is controlled by a centralized scheduling algorithm.
To support high-quality multimedia services on the network, the scheduling
algorithm should be able to minimize the total transmission time for all traffic
flows. Chapter 2 studies the multi-channel scheduling problem in order to explore
the potential of simultaneous transmissions and thus minimize the total
transmission time. For a given network topology with fixed routing tree, we first
analyze how many channels are sufficient for the avoidance of interference. Then
we present an efficient scheduling algorithm along with the channel assignment
strategy for time slot allocation. The simulation results show that our scheme can
improve the system performance substantially as compared with the single
channel system. Also, we observe that double channel settings may provide a
performance similar to the multiple channels.
Chapter 3 studies the routing, time slot allocation and channel assignment
problem in multi-transceiver WiMax mesh networks, where multiple transceivers
are supported on each station and can switch between different channels. We
develop an interference-aware route construction algorithm, which construct a routing tree during the network entry process, in order to minimize the
interference. We also propose a time slot allocation algorithm for
multi-transceiver networks. The simulation results show the impact of channels
and transceivers on total transmission time.
In WiMax mesh networks, transient traffic between neighbor stations can be
controlled by an uncoordinated distributed scheduling algorithm. In this algorithm,
a three-way handshake must be initiated before data transmission. If the
handshake fails, the transmitter must wait for a certain period before its next
transmission. In Chapter 4 we analyze the performance of this algorithm. Due to
the complexity of this problem, we only consider infinite networks with grid
topology where all stations are identical. The behavior of each station in stable
stage can be described as a Markov regeneration process. We analyze the impact
of neighbors on the transmission fail probability of a certain station, then calculate
the system throughput. In the simulation part a custom simulator is used to
validate the effectiveness of our analytical model.
Chapter 5 studies the problem of resource management on hybrid mesh
networks, where WiMax is used as the backbone. We propose a cross-layer
resource publishing/discovery schema for both grid resources and p2p resources.
Besides, a time slot allocation algorithm is presented for the BS to coordinate all
transmissions of resource management messages.
Although the PHY and MAC layer specifications of WiMax mesh networks
have been well defined, there is still work to do to increase the systemthroughput
and improve the quality of service. In final chapter, we summarize our main
contribution and conclude this thesis by pointing out our future work.|
|Online Catalog Link: ||http://lib.cityu.edu.hk/record=b3008254|
|Appears in Collections:||CS - Doctor of Philosophy |
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