後卓越計畫 進度報告 楊舜仁老師實驗室 2008.01.07
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後卓越計畫 進度報告 楊舜仁老師實驗室 2008.01.07. Objective. Investigate the bandwidth management mechanisms for IEEE 802.16j networks. The goal of bandwidth management increase system capacity increase bandwidth utilization increase system throughput reduce new connection blocking probability - PowerPoint PPT PresentationTRANSCRIPT
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後卓越計畫進度報告楊舜仁老師實驗室2008.01.07
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Objective Investigate the bandwidth management
mechanisms for IEEE 802.16j networks. The goal of bandwidth management
increase system capacity increase bandwidth utilization increase system throughput reduce new connection blocking probability reduce handoff connection force-termination probability reduce the number of handoffs
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IEEE 802.16jMultihop Relay Network
The main concept of multihop relay network is to establish relay stations (RS) as relay media between BSs and MSs.
RS: lower power, smaller coverage (relay station cell, RS-cell)
BS: higher power, larger coverage (base station cell, BS-cell)
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IEEE 802.16j Frame Structure for Data Transmission In IEEE 802.16 networks, each frame has a fixd duration. Each frame contains one downlink and one uplink subframe, and the fra
me is diveided into an integer number of physical time slots, which help to partition the bandwidth easily.
In IEEE 802.16j, the downlink path includes BS to MS, BS to RS and RS to MS, while the uplink path includes MS to BS, RS to BS and MS to RS. The radio resource in IEEE 802.16j may be allotted to RSs in a pre-determined and fixed way.
TimeFrame #n-2 Frame #n-1 Frame #n Frame #n+1 Frame #n+2
Downlink Subframe Uplink Subframe
100 20 25 10 5 20 20
preamble BS bursts
(including BS to MS and BS to RS)
RS #1Bursts(RS to MS)
RS #3Bursts(RS to MS)
RS #4Bursts(RS to MS)
RS #5Bursts(RS to MS)
RS #6Bursts
(RS to MS)FCH
MAP RS #2
Bursts(RS to MS)
Downlink Subframe
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Bandwidth Repacking
RSj
Bursts
preamble
BS bursts RSi
BurstsRS
Bursts ...FCH
MAP RSj
Bursts
BS
RS-cellRS-cellj
RS-celli
RS-cellRS-cell
BS
RS-cell
RS-celli
RS-cellRS-cell
MS (connection attempt)
preamble
BS bursts RSi
BurstsRS
Bursts ...FCH
MAP
(a)
(c)
(b)
(d)
RS-cellj
MS (with repacking candidate)
MS (connection attempt)connection
attempMS (with repacking candidate)
x
x
Serving repacking candidate
f
Idle time slots
z
yy z
Serving repacking candidate
Serving connection attemp
x-y
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Problem Statement ofBandwidth Repacking Assume that there are idle time slots in RS-cellm, but no re
packing candidates in RS-cellm due to no MS directly served by BS.
no available time slots
idle time slots
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Bandwidth Carrying
preamble
BS bursts RSm
BurstsRS
Bursts ...FCH
MAP RSn
Burstsb a
BS RSm RSn
(4)
preamble
BS bursts RSm
BurstsRS
Bursts ...FCH
MAP RSn
Burstsb a
BS RSm RSn
BSRS-cell
RS-celln
RS-cellRS-cell
RS-cellm
(a)
BSRS-cell
RS-celln
RS-cellRS-cell
RS-cellm
(b)
MS
preamble
BS bursts RSm
BurstsRS
Bursts ...FCH
MAP RSn
Burstsb a
BS RSm RSn
(3)
a
b MS
MS
a
b
(1)
(2)
under-loaded over-loaded