Transcript Agenda for WWRF Working Group 4 Session

Stand und zukünftige attraktive Arbeitsgebiete
für den
Lehrstuhl für Kommunikationsnetze
Prof. Dr.-Ing. Bernhard Walke
Kommunikationsnetze, RWTH Aachen
[email protected]
Sitzung des vorbereitenden
Berufungsausschusses Kommunikationsnetze
Mo. 19. Dezember 2005
Communication Networks
Wireless Technology Positioning
Mobility / Range
Vehicle
High Speed
Vehicular
Rural
Vehicular
Urban
FlashOFDM
(802.20)
GSM
GPRS
3G/WCDMA
Walk
Pedestrian
Fixed
EDGE
Nomadic
Fixed urban
Indoor
Personal Area
HSDPA
IEEE
802.16e
DECT
WLAN
(IEEE 802.11x)
bluetooth
0.1
1
IEEE
802.16a,d
10
Communication Networks, Aachen University (RWTH)
User data rate
100
Mbps
2
Facts in Communication Networks and Protocols
• Digital networks: Fully automated operation;
IP Multimedia Sub-System (IMS) is hot issue for future research
• Application layer data transmission rate
–
–
–
–
•
•
•
•
•
•
•
•
•
•
Core Network: excessivly high up to Tera bit/s
Wired local loop: ISDN (128 kbit/s) ->xDSL (6-20->1000 Mbit/s)
Wireless (WLAN) 5 Mbit/s -> 25 - 1000 Mbit/s)
Mobile communication: increasing from ISDN to 100 Mbit/s data rate
Increase in # of air interfaces competing -> multimode operation
Multi-homing: Use of multiple networks/services at same time
Radio resource control for wireless access networks: challenging
Resource Re-use Partitioning (interference avoidance)
Internet Protocol IPv6/8 to be understood/developed
Quality of Service responsive network design: challenge
Security & Privacy in comms. nets needs efficient solutions
Multi operator network co-operation is unsolved
Low cost mobile Internet access will need another decade to come
Next wireless/mobile generation will not be the final one
Communication Networks, Aachen University (RWTH)
3
Status and future research funds in ComNets‘ working
domain: Network Design and Evaluation Research
• „Broadband for All“ is a main goal in Europe: The research funding
in large scale will continue over the next decade
• Networks and Protocols Research
– large amount of unsolved problems
– ComNets (& MobNets) don‘t have severe academic competition in EU
– Is key for the development & operation of distributed systems like
power plant, automated factory, networked IT centre, process control
plant, Airbus, in car/in home infrastructure, etc.
• Current position of ComNets
•
•
•
•
– EU funds expenditures ranking in 2004: RWTH=ComNets is rank 4 for
all broadband disciplines, including PHY
– Exceptionally strong BMBF funding: cooperation with many companies
– About 1.450 ComNets research publications downloads per month
3rd parties‘ funds appear available for at least another decade
ComNets students‘ profile perfectly fits the markets‘ needs
AWRC and UMIC cluster will need ComNets‘ current expertise
ComNets during the last 15 years had an average per year of
– 7 peer reviewed journal articles, 35 peer reviewed conference papers
– 43 Diploma theses
– 3.4 Ph.D. theses
1 monography, 2 course books, all published by J. Wiley&Sons 2000+
Communication Networks, Aachen University (RWTH)
4
Download Statistics from 1/2001 to 10/2005
14000
12000
10000
8000
Total number of documents downloaded: 84.681
 Average of 1435 downloads/month
6000
4000
2000
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Communication Networks
Paper Downloads by Country in 2005
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(1,76%)
(1%)
(0,9%)
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Communication Networks, Aachen University (RWTH)
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others
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(0,41%)
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(0,43%)
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UA: Ukraine
MY: Malaysia
13
(0,55%)
00
PL: Poland
RU: Russian Federation (0,49%)
0
(0,59%)
12
CH: Sw itzerland
00
(0,6%)
(0,59%)
0
BR: Brazil
ID: Indonesia
11
(0,6%)
00
(0,67%)
AT: Austria
10
(0,68%)
FI: Finland
00
(0,86%)
GR: Greece
90
SE: Sw eden
00
NL: Netherlands
80
(1,01%)
ES: Spain
00
AU: Australia
70
(1,02%)
00
CA: Canada
60
(1,35%)
(1,17%)
00
IT: Italy
TW: Taiw an
50
IN: India
FR: France
(2,1%)
(1,99%)
00
KR: Korea
1380
803
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JP: Japan
30
(17,56%)
CN: China
6626
00
DE: Germ any
GB: United Kingdom
18083
(47,93%)
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US: United States
6
Einordnung ComNets/MobNets
Technologien und Plattformen: Produktion/Entwicklung wandern
tendenziell in Weltregionen mit geringen Lohnstückkosten aus.
Prozessoren,
Chips,
Bauelemente,
Platinen,
USB Stick,
usw.
PC, Server,
Mobile Phone,
Funkstrecke,
Lokales Netz,
Motor/Umformer,
Transformator,
Elektrofahrzeug
Internet, Mobilfunknetz, SMS, MMS,
Glasfasernetz,
Google/Yahoo
Hochregallager,
Navigation,
Automatisierte Fertigung, Steuerungssoftware
Fabrik, Airbus,
für komplexe PlattTransrapid
formen und Systeme,
Middleware & embedded
Software
ComNets/MobNets Research/Teaching
Schaltungstechnik
Communication Networks, Aachen University (RWTH)
7
Multimedia Internet Service Platform
Communication Networks, Aachen University (RWTH)
8
ComNets Simulation Concepts
2
7
Layered structure:
6
Link level
…focussing the radio transmission
3
1
4
5
System level
…focussing the entire network behaviour
Protocol level
…focussing radio network protocols
reading
packet call
Communication Networks, Aachen University (RWTH)
9
Current Work at ComNets I
Link Level Simulator of the OFDM
transmission chain
– SystemC based including C++ code
– Detailled implementation of
transmitter and
receiver, including scrambler, RS/CC
codec,
interleaving, Modulation etc.
– Channel: AWGN, SUI-1 und SUI-5
– IEEE 802.16a conformant
Result: Channel model:
Bit error rate = f(C/(N+I))
*SUI=Standford University Interim (for outdoors morpho)
CP Append
CP Remove
IFFT
FFT
Preamble Insert
Preamble Extract
Pilot Insert
Pilot Exractt
Equal
Modulate
Demodulate
Bit-Intleave
Bit-Deintleave
ByteIntleave
ByteDeintleave
Puncture
Depuncture
Conv. Encode
Conv. Decode
RS Encode
RS Decode
Scramble
Descramble
Source
Sink
Communication Networks, Aachen University (RWTH)
Channel
Estimate
Channel
10
System Level Simulations
• Stochastic event driven simulation for traffic
performance evaluation of mobile radio networks
based on implementation of
–
–
–
–
–
Radio network protocols (simplified)
Radio resource management strategies
Multi-cellular radio propagation environment
Multi-network / multi-system coexistence
Time-variant traffic and actual interference
characteristics
– Input from link-level simulation
 ComNets’ expertise in entire network evaluation
 ComNets tools are being used to drive standardisation of
current and future wireless/mobile systems
Communication Networks, Aachen University (RWTH)
11
Protocol Level Simulation: Parameters
• Radio access mode
–
–
–
–
–
–
Duplex mode (FDD, TDD)
Carrier frequencies (FDMA)
Bandwidth
Radio frame
Time slot structure (TDMA)
Spreading (CDMA)
• Radio resource
management
– Thresholds
– Timer
– Target values
• Scenario description
• Services
– Type (voice, web, video)
– Characteristics
– Switching (circuit,
packet)
– Priority
– Associated bearer
service
• Evaluation
– Value ranges
– Resolution
• Station data
– Position, mobility
– Power range
Communication Networks, Aachen University (RWTH)
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Leistungsbewertung: Simulationsumgebung
Lastgenerator
Sprache Status
HTTP SMTP FTP
TCP
IP
WAP
WTP
UDP
AVL
stochastisches
Modell
MM
Protokollmodell
Instanz
Basisstation
Mobilstation
Um
LLC
LLC
MAC
MAC
Kanalmodell
PHY
BU TU RA HT
PHY
statistische Auswertung
Moment
LRE PDF/CDF Histogramm
Communication
Networks, Aachen University (RWTH)
e
13
Netz-Architektur für GSM und den
General Packet Radio Service (GPRS)
Communication Networks, Aachen University (RWTH)
14
GSM/GPRS Protokoll-Stapel
Anwendung
Anwendung
UDP/T CP
UDP/T CP
IP
IP
SNDCP
SNDCP
GTP
GTP
LLC
LLC
UDP/T CP
UDP/T CP
RLC
RLC
BSSGP
BSSGP
IP
IP
MAC
MAC
Netz
Dienste
Netz
Dienste
L2
L2
PHY
PHY
L1bis
L1bis
L1
L1
MS
Um
BSS
Gb
detailgetreu
modelliert
SGSN
Gn
GGSN
IP
IP
L2
L2
L1
L1
Gi
Hos t
vereinfachtes
Modell
Communication Networks, Aachen University (RWTH)
15
Wartenetz Modell und Anwendung zur Modellierung
eines Teilnehmer-Rechensystems
ni
xi
Station
i
qij = Übergangsraten Matrix
K Stationen
N Aufträge
q
0i
EIN
Auftragsverkehrslast
q
- stationsspezifische Bedienstrategie
nj
q ij
xj
Station
j
q
0j
i0
q
- Wartepuffer mit Prioritäten
- Ergebnisse:
P(Nj = nj);
Wartezeitverteilung
Stationsauslastung
Durchsatz pro Auftragsklasse usw.
j0
AUS
geschlossen
Abgangsrate X 0
x0
Terminal
Teilnetz
EIN
Zentrales Teilnetz
AUS
M Terminals
Z Denkzeit
EIN
AUS
K Stationen
N Aufträge (O < N < M)
Communication Networks, Aachen University (RWTH)
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Modellierung: Quelle für Sprachpakete über GPRS
Paketgröße
Aktive Phase
Inaktive Phase
SID Paket
24 byte
Modell der
Verkehrsquelle
4 byte
t
FCFS
λ1
Wartemodell mit
stochastischen
Ankunfts- und
Bedienprozessen
und
Bedienstrategie
RR
λi
Übertragungskanal
λN
Communication Networks, Aachen University (RWTH)
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Zustands-Übergangsdiagramm einer Markov Kette
Zustand= aktive Sprachquellen N(t)=i, Pufferbelegung
Übergänge aus den Zuständen N(t) = i. Aus N(t) sind (nach je 60 ms Übergänge zu N(t+1) =
i+1, N(t+1) = i-1 und N(t+1) = i-3 möglich entsprechend den Übergangswahrscheinlichkeiten:
p00   pQuelle bleibt inaktiv 
2
p01  2  pQuelle bleibt inaktiv  pQuelle wird aktiv
p02   pQuelle wird aktiv 
2
p10  pQuelle wird inaktiv  pQuelle bleibt inaktiv
p11   pQuelle bleibt aktiv  pQuelle bleibt inaktiv    pQuelle wird inaktiv  pQuelle wird aktiv 
p12  pQuelle bleibt aktiv  pQuelle wird aktiv
p20   pQuelle wird inaktiv 
2
p21  2  pQuelle bleibt aktiv  pQuelle wird inaktiv
p22   pQuelle bleibt aktiv 
2
p22
2,0
2,i-3
2,i-2
2,i-1
p21
2,i
2,i+1
2,NQ
p12
p21
i = aktive Sprachquellen
p11
1,0
1,i-3
1,i-2
1,i-1
Zustand: i,j
1,i
1,i+1
p02
1,NQ
p10
j = Pakete im Puffer
p01
0,0
0,i-3
0,i-2
0,i-1
0,i
0,i+1
0,NQ
p00
Communication Networks, Aachen University (RWTH)
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Mathematische Verkehrsleistungs-Analyse für GPRS Sprache
1
800
0.9
700
0.8
1500 ms
95-Perzentil der Wartezeit
0.7
Simulated
P(X>x)
0.6
Calculated
0.5
0.4
2s
0.3
1.5 s
0.2
600
1000 ms
500
Calculated
400
Simulated
300
750 ms
200
500 ms
1s
500ms
0.1
100
0
0
0
20
40
60
80
Warteschlangenlänge (x)
Komplementäre Verteilungsfunktion der
Warteschlangenlänge für verschiedene
mittlere Sprach-Phasenlängen
(mittlere Sprachpausenlänge =1 s)
100
0.5
0.7
0.9
1.1
1.3
1.5
1.7
1.9
Mittelwert der Sprachpausenlänge [s]
95-Perzentil der Wartezeit von
Sprachpaketen bei 10 Sprachquellen
Communication Networks, Aachen University (RWTH)
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UMTS (2000): System Throughput & BER
Block Error Rate at 256 kbit/s
1
No. of Mobile Stations = 10
No. of Mobile Stations = 30
No. of Mobile Stations = 60
No. of Mobile Stations = 100
No. of Mobile Stations = 150
No. of Mobile Stations = 200
No. of Mobile Stations = 250
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Maximum System Throughput
for WWW traffic reached with
64 kbit/s DTCH
0
0.2
0.4
0.6
Block Error Probability
0.8
1
the BLER increases with
increased Number of
Stations, reducing
throuphput accordingly.
Communication Networks, Aachen University (RWTH)
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Available
er
s
at
di
st
an
ce
d
Actual Available Capacity
vs. Requested Capacity
Us
Range limitation of broadband APS by
– high attenuation at high frequencies
– limited transmission power (EIRP)
– Unfavourable radio propagation conditions, e.g.,
in urban areas
 Increased # of BS needed with increased carrier
frequency to cover a given area
 High CAPEX and OPEX
 High cost/bit transmitted
Capcity/
Area Element
Cell Capacity over Distance
is Inverse to the Needs
High capacity available close to AP only.
Under constant user density:
 Number of users increases with d
 Cell capacity offered per area element differs from
capacity requested by users
 Future trend makes it more worse
2005
Cell border
Requested by users
2010
Location of
Base Station
Distance d
New Deployment Concepts
required to
Sources:
B. Walke, H. Wijaya, D.C. Schultz: The Application of Relays in
Infrastructure-based Future Mobile Radio Network Deployment Concepts
Submitted: VTC 2006 Spring, Melbourne, Australia
T. Irnich, D.C. Schultz, R. Pabst, P. Wienert: Capacity of a Relaying
Infrastructure for Broadband Radio Coverage of Urban Areas.
Proceedings of the 10th WWRF meeting, New York, 10/2003
bring
broadband to wider
area than possible with one
base station in current
systems
Reduce the cost/bit
transmitted by 2 to 3 orders
of magnitude
Communication Networks, Aachen University (RWTH)
21
Relay Enhanced Cells (REC)
Using Fixed Relay Stations (FRS)
Pros:
• Relays in REC
AP
– don’t need a wired backbone access (lowers
CAPEX and OPEX)
FRS
– Full flexibility of relays (re-)positioning
• Relays introduced to a cell can
– enlarge the coverage area bbbbb(using
antenna gain)
– Increase capacity at cell border
– balance the capacity/area element
– reduce transmission power
• increasing public acceptance
• Reducing co-channel interference
• (Movable) Relays support
– fast network rollout,
– outdoor to indoor service
Cons:
– Exploitation of macro-diversity
• In band relays consume radio resources
(co-operative relaying)
•
•
Out of band relays need multiple transceivers
Relays introduce extra delay
Source: Walke, Bernhard; Wijaya, Harianto, Schultz, Daniel C.: The Application of Relays in Infrastructure-based
Future Mobile Radio Network Deployment Concepts. Submitted: VTC 2006 Spring, Melbourne, Australia
Communication Networks, Aachen University (RWTH)
22
Cellular Multi-hop deployment in highly shadowed environment
Channel Group 1
Channel Group 2
1.
2.
3.
AP
Source:
ComNets 2003
Line of Sight
Communication Networks, Aachen University (RWTH)
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Capacity at Relay (FRS) with Antenna Gain
P. Gupta and P. R. Kumar: The capacity of wireless networks. IEEE Transactions on
Information Theory, 46(2):388 - 404, 2000: Multi-hop reduces capacity.
FRS 1
FRS 4
AP
FRS 3
FRS 2
capacity (Mbit/s)
Pabst, Ralf; Esseling, Norbert; Walke, Bernhard: Fixed Relays for Next Generation Wireless
Systems - System Concept and Performance Evaluation. Journal of Communications and
Networks, Vol.7, No. 2, p.p. 104-114, Korea, 06/2005: Spectrum capacity can be increased
by multi-hop, if mesh hops are narrow beam based.
25
20
6.67 Mbit/s
15
10
5
0
0
•
•
•
FRS sub-cell
AP sub-cell
5
10
15
20
25
30
35
40
FRS receive antenna gain (dBi)
All AP capacity “transferred” to one FRS sub-cell
Capacity of FRS rises with antenna gain until highest PHY mode can be applied
Cost of relaying: 6.67 Mbit/s of AP capacity at 30 dBi gain (example: IEEE 802.11a PHY using a WiMax like
MAC protocol)
Communication Networks, Aachen University (RWTH)
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ComNets Vision of a Mobile Low Cost Internet Access:
Relay-based Cellular Wireless Mobile Broadband System
Relay
Enhanced Cell
Access Point
1. Hop Relay
2. Hop Relay
Source: Walke, Bernhard; Pabst, Ralf; Schultz, Daniel C.: A Mobile Broadband System
based on Fixed Wireless Routers. Proc. ICCT 2003 Intern. Conf. Comm. Techn., 04/2003
Communication Networks, Aachen University (RWTH)
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Reuse shift parameter for a N = 12 Relay-Cell cluster
and Cell Radius R
f3
f1
f6
f4
AP
FMT
Antenna
j
f5
R
R
h
D3
f2
f0
D2
i
f5
j
f 10
i
f 11
f9
j
f9
i
D4
f8
f7
f5
f1
i
h
D1
j
f2
i
i
D5
f5
f 10
f1
f0
f3
f5
j
D6
j
f5
f7
f4
f6
f8
f9
Communication Networks, Aachen University (RWTH)
26
346m
single hop cell
200m
central cell
Ende-zu-Ende-Durchsatz [Mbit/s]
End-zu-Ende-Durchsatz [Mbit/s]
Single-Hop and Relay Enhanced Cell Throughput
compared (3 FRS)
40
Area
=
30
20
10
-600
-600
-400
En -200
tfe
rnu
0
ng
AP
200
un
d M 400
T(
600
y)
[m
]
-400
]
-200
[m
(x)
0
T
d M 400
200
un
P
A
400
ng
600
rnu
e
f
t
En
y
0
200
Iso-throughput curves
-200
AP
30
FMT
25
20
FMT
15
10
5
0
-400
En-400
tfe -200
rn 400
un
g
0
AP
un
d
200
(R
)M
T
400
(y
)[
m
]
200
-400
-200
0
200
400
P
gA
un
n
r
tfe
En
T
)M
(R
d
un
]
[m
(x)
200m
30
12Mbit/s
Esseling, Norbert: Ein Relaiskonzept
für das hochbitratige drahtlose lokale Netz
HIPERLAN/2, ABMT 42, 1. Auflage Jul/2004,
307 Seiten, ISBN: 3-86130-169-5
www.comnets.rwth-aachen.de/
Dissertati.178.0.html
10Mbit/s
8Mbit/s
12
0x
28
24
20
14 16
6Mbit/s
4Mbit/s
-200
200m
2Mbit/s
-400
Communication Networks, Aachen University (RWTH)
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End-to-End Throughput Downlink
along y-Axis
45
End-to-End Throughput [Mbit/s]
40
12er (346m)
3er, 3FMTs
7er, 3FMTs
7er (346m)
12er,
3FMTs
3er (346m)
3er (346m), kein FMT
3er (200m)
7er (346m), kein FMT
3er, Relais-Sys. 12er (346m), kein FMT
>1-Hop-Sys.
y
7er, Relais-Sys.
>1-Hop-Sys.
12er, Relais-Sys.
>1-Hop-Sys.
35
30
25
1.Hop
20
12er 1.Hop
15
7er
2.Hop
10
1.Hop
3er
2.Hop 2.Hop
5
0
0
50
100
150
200
250
Distance [m]
300
350
Communication Networks, Aachen University (RWTH)
400
28
346m
single hop cell
200m
central cell
Ende-zu-Ende-Durchsatz [Mbit/s]
End-zu-Ende-Durchsatz [Mbit/s]
Single-Hop and Relay Enhanced Cell Throughput
compared (3 FRS)
40
Area
=
30
20
10
-600
-600
-400
En -200
tfe
rnu
0
ng
AP
200
un
d M 400
T(
600
y)
[m
]
-400
]
-200
[m
(x)
0
T
d M 400
200
un
P
A
400
ng
600
rnu
e
f
t
En
y
0
200
Iso-throughput curves
-200
AP
30
FMT
25
20
FMT
15
At 11,8 dbi
10
5
0
-400
En-400
tfe -200
rn 400
un
g
0
AP
un
d
200
(R
)M
T
400
(y
)[
m
]
200
-400
-200
0
200
400
P
gA
un
n
r
tfe
En
T
)M
(R
d
un
]
[m
(x)
200m
30
12Mbit/s
Esseling, Norbert: Ein Relaiskonzept
für das hoch bitratige drahtlose lokale Netz
HIPERLAN/2, ABMT 42, 1. Auflage Jul/2004,
307 Seiten, ISBN: 3-86130-169-5
www.comnets.rwth-aachen.de/
Dissertati.178.0.html
10Mbit/s
8Mbit/s
12
0x
28
24
20
14 16
6Mbit/s
4Mbit/s
-200
200m
2Mbit/s
-400
Communication Networks, Aachen University (RWTH)
29
Multi-hop Relay Technologies
R. Pabst, B. Walke, D.C. Schultz:Relay-Based Deployment Concepts for Wireless and Mobile Broadband
Radio. In IEEE Communications Magazine, p.p. 80-89, New York, US, 09/2004
Time domain relay
(FWR)
Frequency domain relay
Frequency domain relay
with pure forwarding
Communication Networks, Aachen University (RWTH)
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Forwarding Concept: Case 2
•
One carrier frequency
•
Exploitation of environment
FRS 1
 2 Groups of FRSs that can
serve their MTs in parallel
FRS 4
AP
FRS 2
FRS 3
MTs served by FRS#1
MTs served by FRS#3
MTs served by FRS#2
MTs served by FRS#4
FRS#2
FRS#1
FRS#3
FRS#4
served by AP served by AP served by AP served by AP
TAP-FRS
MTs served by AP
TMP-MT
TMP-MT
Time
Communication Networks, Aachen University (RWTH)
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Coordination Across BS
Resource Partitioning
Cell Type C
Cell Type B
Cell Type A
Time Slot to Feed FRSs
Time Slot X
Time Slot Y
Time Slot Z
MTs served by FRS#A1 MTs served by FRS#A3
MTs served by FRS#A2 MTs served by FRS#A4
FRS#A1
FRS#A2
FRS#A3
FRS#A4
served by AP served by AP served by AP served by AP
MTs served by AP A
MTs served by FRS#B1 MTs served by FRS#B3
MTs served by FRS#B2 MTs served by FRS#B4
FRS#B1
FRS#B2
FRS#B3
FRS#B4
MTs served by AP B
served by AP served by AP served by AP served by AP
FRS#C1
FRS#C2
FRS#C3
MTs served by FRS#C3
MTs served by FRS#C1
MTs served by FRS#C4
MTs served by FRS#C2
FRS#C4
MTs served by AP C
served by AP served by AP served by AP served by AP
TAP-FRS
TMP-MT
TMP-MT
Time
Communication Networks, Aachen University (RWTH)
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Coordination Across BSs
•
•
FRS 4
AP
FRS 2
FRS 1
FRS 3
FRS 1
FRS 3
FRS 4
AP
FRS 2
AP
FRS 2
FRS 1
FRS 3
FRS 4
FRS 3
FRS 4
AP
FRS 2
FRS 1
Cell Type A
FRS 2
FRS 1
FRS 3
FRS 4
AP
Cell Type B
FRS 4
AP
FRS 2
FRS 1
FRS 3
Cell Type C
FRS 1
FRS 3
FRS 4
AP
FRS 2
Only one Carrier Freq. Required to
cover the scenario
Distance between “co-channel”
sub-cells: 460 m
Communication Networks, Aachen University (RWTH)
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Mesh Network applied to IEEE 802.11 WLAN:
ComNets Proposal
•
•
•
Works under IEEE 802.11 PCF mode
MPs operate as PC (point coordinator)
Beacons with the format of IEEE 802.11’s from the PC inform nodes of the
CFP (contention free period) and CP (contention period)
MN works during CFP, IEEE 802.11 on CP
•
Note:
•
Beacon
Guard time
Coexistence of MN with IEEE 802.11e
MN
IEEE802.11e
MN
IEEE802.11e
CFP
CP
CFP
CP
MN
The guard times are fixed
Source: Zhao, Rui; Walke, Bernhard; Hiertz, Guido: W-CHAMB (Wireless CHannel Oriented Ad-hoc Multi-hop Broadband): A new
MAC for better support of Mesh networks with QoS, Contribution to IEEE 802.11 WLAN Working Group Session, September 2004,
p. 5, Berlin, Federal Republic of Germany, 09/2004 ComNets 2004
And: Wijaya, Harianto: Broadband Multi-Hop Communication in Homogeneous and Heterogeneous Wireless Lan Networks
ABMT 46, 1. Auflage Feb/2005, 237 Seiten, ISBN: 3-86130-175-X, available at: www.comnets.rwth-aachen.de/Dissertati.178.0.html
Communication Networks, Aachen University (RWTH)
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Mesh Network (MN) and IEEE 802.16 combined.
ComNets proposes dedicated mesh network protocol
•
•
•
•
Provides meshing of APs and Relays and MS access in the same channel within a Relay
Enhanced Cell (REC)
Base Station/Relay Node are called MeshPoint (MP)
MN connects MPs in RECs and MPs of adjacent RECs using MAC-frame periodic slots
IEEE 802.16 MAC frame serves MSs on first hop to MP
Note:
Beacon
Guard time
Coexistence of MN with IEEE 802.16
MN
IEEE802.16
MN
IEEE802.16
Periodic
Frame specific
Periodic
Frame specific
MN
The guard times are fixed
Source: Mangold, S.; Habetha, J.; Choi, S.; Ngo, C.: Coexistence and interworking of IEEE 802.11a and ETSI
BRAN HiperLAN/2 in multi-hop scenarios. In 3rd IEEE Workshop Wireless Local Area Networks, Boston, 09/2001
Communication Networks, Aachen University (RWTH)
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Possible IEEE 802.16 WiMAX Mesh Solution
•
•
BSs connected by MN on separate frequency channel
IEEE 802.16 between BS and SSs or RNs (one-hop forwarding possible)
Communication Networks, Aachen University (RWTH)
36
Coexisting WLANs: The Game Model
has a
WLAN
player
supports
1..*
application
discounting
factor
strategy
determines
action
determines
utility
define
required QoS
parameters
long-term maximization
takes into account
defines
demanded QoS
parameters
behavior
depends
on
leads to
mutual
interference
within SSG
observed QoS define
parameters
payoff
(outcome)
QoS parameters
Theta (throughput)
Delta (delay)
Xi (jitter)
• Overlapping WLANs are represented by a player
• Each player has a strategy to determine what action to select
• An action specifies a behavior
• The players optimize the payoff (i.e. outcome) of the game
Communication Networks, Aachen University (RWTH)
37
WLAN Spectrum Coexistence Scenario:
Two 802.11e QBSSs sharing one Channel
•
•
Basic Service Sets are modeled as players that attempt to optimize
their outcomes
The coexistence problem is modeled as a repeated, stage-based game
signals communication
and control
QSTA: Quality Station
HCF: Hybrid Coordinator
Function
QSTA
QSTA
QSTA
HCF 1
Player 1
represents offered
EDCF traffic within
the OQBSS
QSTA
HCF 2
Player 2
EDCF QSTA
Player 3
detection ranges
of HCFs
Communication Networks, Aachen University (RWTH)
38
Nash Equilibrium
Definition:
“No player can
gain a higher
payoff in deviating
from Nash
Equilibrium”
player i’s classifications of
payoff of
opponent’s behavior
player -i: 1
Vi(a-i,ai)
player -i defects player -i cooperates
player -i
defecting
stable
point
player
i of
interaction
defecting
(C|D)
payoff
under
cooperation
1.
(C|C)
0.5
 stable and thus
predictable point of
interaction
1.
2.
Nash
Equilibrium
(D|C)
3.
gain through
deviation
(D|D)
0
0.5
punishment through
opponent defection
Communication Networks, Aachen University (RWTH)
1
payoff of player i:
Vi(ai,a-i)
39
Strategies in Multi Stage Games (I)
•
Strategies describe the alternatives a player has for an action
within a Multi Stage Game
Consideration of interaction with decisions of influenced players
Strategies modeled as state machines
•
•
90
90
n=1
n=1
C
50%
(*)
(C)
(*)
90
n=1
C
D
90
90
C
D
all outcomes
except (C)
(1) COOP
•
50%
90
90
50%
(2) GRIM
Example: Dynamic trigger
strategy TitForTat (TFT) – the
player cooperates if the opponent
cooperates and vice versa
50%
(3) RANDOM
(C)
(D)
90
n=1
(4) TFT
90
C
D
(D)
90
90
(C)
Communication Networks, Aachen University (RWTH)
40
Strategies in Multi Stage Games (II)
•
Multi Stage Games of multiple strategies, evaluated in terms of
observed throughput (Θ) and (TXOP) delay
TFT versus various strategies
•
•
RANDOM versus various strategies
TFT: Player’s behavior follows the opponent’s leading to
predictable MSG outcomes  QoS guarantee
RANDOM: frequent fluctuation in behavior implies instable game
course  unsatisfying QoS degradation
Communication Networks, Aachen University (RWTH)
41
ComNets Concept for a Flexible Protocol Stack
reconfigurable
protocol stack
(classic) single
protocol stack
multi-mode (composite)
protocol stack
same
property
system specific
protocol stack
specific functionality
reconfiguration
management/functions
modes convergence
management/functions
common functionality
generic
protocol stack
specific parts
mode x
mode 1
different
mode 2
protocol
functions
protocol
architecture
data
structures
protocol
framework
protocol
management
• Protocols share a lot of commonalities, that can be exploited in an
efficient multi-mode capable wireless system
 Generic Protocol Stack
as “toolbox of parameterizable protocol functions”
• Generic part: Tradeoff of general usability vs. implementation effort
Communication Networks, Aachen University (RWTH)
42
WINNER Multi-Mode Protocol
Architecture
configuration and
information transfer
controlplane
generic stack
management
RRCRRC-g
r2
RRC-r1
joint mode 1/2 stack
management
(2) management
that is specifically
optimized for the
mode1 and
mode2 in use
 probably more
efficient
reconfiguration
management
Stack Management
alternatively:
(1) generic
management
 more flexible
alternatives
RLC-g
PHY-g
MAC-g
MAC-r2
MAC-r1
PHY-g
PHY-g
PHY-s2 PHY-r2
PHY-s2 PHY-r1
management
control
modesswitching
and
coexistence
user
Communication Networks, Aachen University (RWTH)
43
Reference Structure of Layer or Sublayer
L(N) SAP-s1.1
L(N) SAP-s1.2
L(N) SAP-s2.1
L(N) SAP-s3.1
L(N) SAP-s2.2
L(N) SAP-g
L(N) - mode 1, 2 or 3
composes
stack
management
(N)-MCM
L(N) – generic part
for mode 1-2-3
convergence
(re)configures
L(N-1) SAP-s1.1
L(N-1) SAP-s2.1
L(N) – mode 1 – specific
part
L(N) – mode 2 – specific
part
L(N) – mode 3 – specific
part
services of layer (N) /
sublayer (N.n)
provided jointly
through generic and
specific parts
L(N-1) SAP-s3.1
(N) Layer Modes Convergence Manager ((N)-MCM):
• Facilitates the structuring of an arbitrary layer into generic and
specific parts
• Responsible for composition and (re-)configuration
• Controlled by the stack management
 Optimization potential is marked up in questioning the necessity
of indicated differences
Communication Networks, Aachen University (RWTH)
44
Realization of the Flexible Protocol Stack
Service Access Point
TCP/UDP / IP
Interface
Composition,
Parameterization
and Data Query
data
RRC
RLC
Stack
Config.
Functional
Unit
mode
specific
generic
PHY
MAC
PHY
PHY
data
Channel (Modem)
(N)-Layer
Configuration
Mode
Specific
(Sub-)layer
Functional
Functional
Functional
Modul
Modul
Unit
Functional
Unit
Data
Interface
Service Access Point
•
•
•
Functionality of the Layers is composed from a toolbox of functional units
Mode-specificness can either be specific modules or specific configuration
/ parameterization of the stack, individual layers or even functional units
Reference Implementation for WINNER Layer 2 currently performed at
ComNets
Communication Networks, Aachen University (RWTH)
45
Spectrum Requirement Estimation at a Glance
Market info
Calculation algorithm
Radio technology info
Future services
Scenarios definition
Capabilities
Offered traffic
Traffic distribution
to Radio Access
Techniques (RAT) &
Radio Environments
Availability/
Coverage
Required Quality of
Service (QoS)
Capacity
dimensioning
Technical spectrum
requirements
Adjustments &
weighting
Communication Networks, Aachen University (RWTH)
46
General Approach for Capacity Calculation
• In packet based systems QoS constraints require certain
amount of free capacity
System
Throughput
Mean Delay
Physical
Layer
Throughput
MAC
Layer
Throughput
Delay
Target
RLC
Layer
Throughput
underload
Usable fraction
of system
capacity
overload
Tmax = Crlc
System Load
100%
Communication Networks, Aachen University (RWTH)
System Load
47
Packet-switched Capacity Calculation
• Required system capacity calculated from M/G/1/FCFS/NONPRE queue
(“head of the line priority queue“)
• Throughput requirements per SC derived under steady state operation
• To meet the delay requirement of a Traffic Class needs proper
dimensioning of capacity C
λ1
Priority 1
Highest priority
β1, β1(2)
λ2
Server
Priority 2
C
β2, β2(2)
λN
Priority N
Parameters of the model:
• λi : arrival rate of packets
with priority i
• βi(i) : i-th moment of service
duration of packets with
priority I
• C: capacity searched for
βN, βN(2)
Lowest priority
Communication Networks, Aachen University (RWTH)
48
Aggregate Spectrum Requirement
Required spectrum [MHz]
Service
environment
UL
Relative change [%]
DL
UL+DL
UL
DL
UL+DL
SE1
18.332
21.742
40.074
40.91
-21.37
-1.44
SE2
130.754
257.224
387.978
12.85
-0.37
3.72
SE3
9.332
9.772
19.304
73.79
-23.55
4.81
Sum
154.418
288.738
447.356
18.00
-3.33
3.28
•
•
•
•
•
•
Results shown above do not include last step of new methodology
(i.e., accounting for multiple operators, guard bands, FSU, etc.)
Some parameters for PS capacity calculation have been reasonably chosen,
other choice would have led to different results
Small difference resulting is more or less coincidence, since a number of
effects partly compensate each other
The scenario considered is not a likely scenario to be looked at in spectrum
requirement calculation in preparation for WRC-07
Comparison shows that results are in line with earlier results
New methodology’s concepts and algorithms represent state of the art
Communication Networks, Aachen University (RWTH)
49
Transport Services & Protocols
4
Radio Resource & Mobility
3
Control
Location Based Services
3
Medium Access & Link Control
2
Protocols
Smart Antenna Protocol
1-2
Support
Communication Networks, Aachen University (RWTH)
Adaptive Protocol Stack Software
Traffic Performance Evaluation
(Theory of Large Systems)
Spectrum Co-existence Research
IEEE 802.11/15/16/21 Standardization
Wireless Networks & Interworking
Fixed and Mobile Networks Convergence
Broadband Wireless Transport Platforms
Mesh Netwks. & Relaying for cellular
Communication Networks (Walke):
“We do mostly layers 2..4”
50
ComNets Profile
http://www.comnets.rwth-aachen.de/ (Oct. 2005)
ComNets research focuses on OSI-layers 2, 3 and 4.
We work also in radio spectrum co-existence & design of adaptive protocol
stack solutions for multi-radios. Some of our people are in domains of the
-spectrum & regulation, - cognitive radios, - SW-defined re-configurable radios.
Research is both strongly theoretical and experimental.
Experimentation capabilities at ComNets cover the „down to bit level“ prototype
like implementation of radio access networks based on software based tools and
include the possibility to implement protocol stacks and new algorithms for test.
Design and Optimisation of Disruptive Deployment Concepts for Future
Cellular Radio is our strongest key research area, this extends to wireless
mesh networks.
We have contributed to standards like GSM/GPRS, ETSI HiperLAN2, IEEE
802.11e,k,s, IEEE 802.15.3, IEEE 802.16 CEN TC 278 DSRC, ITU-R WP8F
spectrum estimation methodology.
Our theoretical basic research, especially in game theory applied to radio systems‘
co-existience in frequency spectrum will hopefully permit better exploitation of
spectrum.
We are leading in mesh networking protocols for wireless systems.
Our wireless broadband multi-hop ad-hoc communication network design
does not have any severe competition.
We are able to evaluate really large communication systems based on the unique
tools that we have developed.
Communication Networks
Radio Resource & Mobility
3
Control
Location Based Services
3
Medium Access & Link Control
2
Protocols
Smart Antenna Protocol
1-2
Support
Communication Networks, Aachen University (RWTH)
52
Adaptive Protocol Stack Software
Transport Services & Protocols
4
Traffic Performance Evaluation
Spectrum Co-existence Research
IEEE 802.11/15/16/21 Standardization
Cross Layer Issues &Low-Power
1/2
Mesh Networks & Relaying for Cellular
Link Layer Protocols
2
Broadband Wireless Transport Platforms
Service Discovery
3
Wireless LANs
Network Optimization & Theory
3
Cognitive Radios and Networks
Advanced Cellular Networks
Personal Area Networks
Transport Protocobls
4
Self-Configuration (ad hoc)
Sensor Networks and Applications
Comparison MobNets (left) and ComNets (right)
Courses, Labs and Seminars
• Networking & Protocols Expertise is a must for
Information Technology Engineers
• Both Curricula
– Information & Communications (ET & IT)
– Technical Computer Science (TI)
Contain mandatory courses and courses to be selected
from catalogues on Networking & Protocols
• The load from Course Lecturing, Labs and
Seminars is by far to big to be shouldered by
one chair
• It is agreed that MobNets is not lecturing
courses in basic studies
Communication Networks, Aachen University (RWTH)
53
Courses, Labs and Seminars by ComNets
Current (stationary) Status
Curriculum
ET&IT u. TI
ET & IT u. TI
lecture, Labs, Seminars
Grundgebiete der Informatik 3
Praktikum Grundgeb. Informatik 1
Type Credits
Mandat V2 Ü1
MandatP4
Responsibles
Walke u. wiss. Mitarb.
Walke/Kraiss und wiMi
TI und ET & IT Komm.Netze u. Verkehrstheorie
TI und ET & IT Praktikum Kommunikationsnetze
MandatV4 Ü2
ElectiveP4
Walke u. wiss. Mitarb.
Walke u. wiss. Mitarb.
ET & IT
ET & IT
ElectiveP3/4
ElectiveV3
Walke u. wiss. Mitarb.
Walke u. wiss. Mitarb.
Praktikum Mobilfunknetze
Seminar Kommunikationsnetze
TI und ET & IT Stochastische Simulationstechnik
CatalogV4 Ü2
TI und ET & IT Praktikum Stochast.Simulationstechnik ElectiveP3/4
Walke/jetzt Lehrauftrag
Walke u. wiss. Mitarb.
Techn. Inform.
Techn. Inform.
Walke/Gebhardt u.a.
Walke u. wiss. Mitarb.
Einführung: Objektorient. Programmierg. Mandat P3
Projekt CORBA
Elective V4
Communication Networks, Aachen University (RWTH)
54
Proposal for Call for Applications
Kommunikationsnetze mit den Anwendungsgebieten:
1. Modellierungstechnik, Verkehrstheorie, Bedientheorie, stochastische
Simulationstechnik mit Anwendungen auf
•
•
Mobile Breitbandnetze (Mesh und Relay-Netze)
Netzoptimierung und Kooperation von Drahtlos- und Mobilfunknetzen
2. Spektrums-Koexistenz Forschung
3. Software Entwicklungsmethoden (UML) für Netze und multi-mode
Terminals
Communication Networks, Aachen University (RWTH)
55
Wesentliche Ergebnisse in 2004
• 38 Conference Papers, 5 Journal Papers, 10 IEEE
Standardisation Contributions
• 6 Awards
• Packet Relays accepted world-wide as disruptive technology:
- capacity enhancement for 2 & 3G systems
- Range extension for wireless broadband systems
• Co-existence of radio research established
• Mobile Web services demonstrated
• Air Interface Multi-Mode operation through Modes
Convergence Manager
• A number of contributions to IEEE 802 Project, namely:
-
.11s Mesh
.15s Mesh
.11 and .15 multi-hop support
.16 spatial multiplexing
Communication Networks, Aachen University (RWTH)
56
Ende
Communication Networks, Aachen University (RWTH)
57