1 efficient backbone synthesis algorithm for multi-radio wireless mesh networks huei-jiun ju and...
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Efficient Backbone Synthesis Algorithm for Multi-Radio Wireless Mesh Networks
Huei-jiun Ju and Izhak RubinElectrical Engineering Department
University of California, Los Angeles (UCLA)WCNC 2006
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Outline
Introduction Related Work Multi-Radio Backbone Synthesis Algorithm
(MR-BAS) Multi-Radio MBN On-Demand Routing
(MR-MBNR) Performance evaluation Conclusions
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Introduction- Mesh Backbone Network Topology
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Introduction- Mesh Backbone Network Topology
The advantage of backbone Mesh Network Easy for routing Power saving Increasing the efficiency
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Introduction- Mobile Backbone Network
(MBN)
Nodes are classified into two categories,
Backbone Capable Nodes (BCNs) and Regular Nodes (RN), based on their ability
In this paper AP nodes are analogous to BCNs while non-AP act as regular RNs.
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Introduction- Motivation
MBN is designed so that it involves a sufficient but not excessive number of backbone nodes.
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Related Work
ETSA (Extended mobile backbone network topology algorithm) Each node have a single radio , use 1-hop
complete neighborhood and 2-hop BN neighbor information and all nodes operate at the same frequency.
CDS construction algorithm Each node have a single radio and make use of
complete 2-hop neighborhood data.
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MR-BSA
In this paper Multi-radio backbone synthesis algorithm (MR-
BSA) is used for constructing and maintaining a backbone network in this paper.
Each AP node is either elected to serve as a BN or is one-hop away from a BN
Backbone Nodes are classified with three type. BN_A , BN_B and BN_C.
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MR-BSA - System model
BN_A
RN
RNRN
RN
BCN
BN_A
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MR-BSA - System model
BN_B
RNRN RN
BN_A
RNRN RN
BN_A
BN_B
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MR-BSA - System model
BN_C
RNRN RN
BN_A
RNRN RN
BN_A
BN_C BN_C
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MR-BSA - System model
AP nodes are equipped with two radio (high capacity channel and low capacity channel) modules and routing intelligence.
Non-AP nodes are only employed a single radio and possessed no routing capability.
Each channel can be operated at its selected data channel. Each node has two timer : Short Timer and Long Timer, and the Long Timer
is set to be 3 times Short Timer.
AP_node
AP_node
Client_nodeClient_node
Client_nodeClient_node
Client_node
一： high capacity channel一： low capacity channel
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MR-BSA -Short Timer expires
When the Short Timer expires, the node broadcast Hello message to it’s neighbor on high capacity channel ( BCN or BN) and low capacity channel.
Node
NodeNode
Node
Hello message
Hello m
essa
ge
Hel
lo m
essa
ge
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MR-BSA -Hello message
Hello message on high capacity channel contains
Node’s ID Status Weight Associated BN ID BN neighbor list
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MR-BSA -Hello message
Hello message on low capacity channel contains
Node’s ID Status Weight Associated BN ID Predecessor node’s ID Number of hops to the closest BN
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MR-BSA -Hello message
Through periodic Hello message exchange Each BCN learns its 1-hop neighborhood and
2-hop BN neighbor across the high capacity channel.
All nodes learn their 1-hop neighborhood across the low capacity channel.
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MR-BSA -Long Timer expires
When the Long Timer expires, the node updates its neighbor lists based on the number of Hello messages received from each neighboring radio within the previous period.
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MR-BSA
Association algorithm is used for constructing the backbone network.
BCN to BN and BN to BCN conversion algorithm is used for maintaining the backbone network.
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MR-BSA- Association Algorithm
In the high capacity channel BCN try to find a BN_A node with highest weight in its 1-hop
neighborhood to associate with. If no neighboring BN is detected, the node attempts to associate
with a BCN. And selecting among all its neighboring BCNs.
BCN
BN_AWeight=3
BN_AWeight=4
BN_AWeight=5
BCN
BCNWeight=3
BCNWeight=4
BCNWeight=5
一： high capacity channel一： low capacity channel BN
Hello m
essage
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MR-BSA- Association Algorithm
In the low capacity channel BCNs and RNs try to find a BN node with highest weight to associ
ate with. If no neighboring BN is detected,
BCNor RN
BNWeight=3
BNWeight=4
BNWeight=5
BCNor RN
BCN BCN
BCN一： high capacity channel一： low capacity channel BN
Hello m
essage
＋
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MR-BSA- BCN to BN conversion Algorithm
BCN to BN conversion algorithm executes based on high capacity channel neighborhood information.
BN_A BN_B BN_C
BCN
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MR-BSA- BCN to BN conversion Algorithm
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MR-BSA- BCN to BN conversion Algorithm
Case : Client coverage condition
RN
RN
BCNWeight=4
RN
BCNWeight=5
BN_A
BCNWeight=3
BCN
BCN
一： high capacity channel一： low capacity channel
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MR-BSA- BCN to BN conversion Algorithm
Case : Local 2-hop BN_A connection
BN_ABN_A
BN_BBCNWeight=5
一： high capacity channel一： low capacity channel
BCNWeight=4
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MR-BSA- BCN to BN conversion Algorithm
Case : Local 2-hop BN_A and BN_C connection
BN_ABN_A
BCNWeight=5
BCNWeight=4
BN_C
BCN
BNBN
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MR-BSA- BCN to BN conversion Algorithm
Case : Local 3-hop BN_A connection
BN_A BN_A
BN_CBCN BCN
BCN
BN_C
＋＋
＋
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MR-BSA- BN to BCN conversion Algorithm
BN to BCN conversion algorithm executes based on high capacity channel neighborhood information.
During the execution of BN to BCN conversion algorithm BN also updates its role as BN_A,B or C
BN_A BN_B BN_C
BCN
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MR-BSA- BN to BCN conversion Algorithm
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MR-BSA- BN to BCN conversion Algorithm
Case : Client coverage condition
BNWeight=4
BNWeight=3
BCN
一： high capacity channel一： low capacity channel
RN
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MR-BSA- BN to BCN conversion Algorithm
Case : Local 2-hop BN_A connection
BN_ABN_A
BN_BBCNWeight=5
一： high capacity channel一： low capacity channel
BCNWeight=4
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MR-BSA- BN to BCN conversion Algorithm
Case : Local 2-hop BN_A and BN_C connection
BN_ABN_A
BCNWeight=4
BCN
BNWeight=3BN_C
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MR-BSA- BN to BCN conversion Algorithm
Case : Local 3-hop BN_A connection
BN_A BN_A
BN_CBNWeight=3
BCNWeight=5
BCN
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Multi-Radio MBN On-Demand Routing (MR-MBNR)
Through use of on-demand routing protocols such as Ad hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR), source-destination routes are discovered by flooding route request (RREQ) packets across the entire network.
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Performance evaluation
Simulation model QualNet V3.6.1 802.11 DCF MAC layer protocol Channel data rate 2Mbps Radio transmission range 300m Short_Timer:2secs Long_Timer:6secs The results have been averaged over 5 randomly
generated topologies.
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Performance evaluation- Backbone Network
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Performance evaluation- Backbone Network
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Performance evaluation
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Performance evaluation- Throughput
Performance (single channel)
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Performance evaluation- Throughput
Performance (single channel)
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Performance evaluation- Throughput
Performance (two channel)
The notation “Lx” represents the results for setting the lowcapacity radio transmit power to x dBm.
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Conclusions
The MR-BSA scheme presented here Guarantees to construct and maintain a connect
ed backbone network Reduce routing overhead and to provide scalabl
e and efficient operation for the wireless network.