Communication Networks
Stand und zukünftige attraktive Arbeitsgebiete Stand und zukünftige attraktive Arbeitsgebiete für den für den
Lehrstuhl für KommunikationsnetzeLehrstuhl für Kommunikationsnetze
Prof. Dr.-Ing. Bernhard WalkeProf. Dr.-Ing. Bernhard WalkeKommunikationsnetze, RWTH AachenKommunikationsnetze, RWTH Aachen
[email protected]@comnets.rwth-aachen.de
Sitzung des vorbereitenden Berufungsausschusses Kommunikationsnetze
Mo. 19. Dezember 2005
2Communication Networks, Aachen University (RWTH)
Long Term 3G Evolution
>2008
Fix
ed
Walk
Veh
icle
Mobility / Range
Indoor
Pedestrian
High Speed
VehicularRural
Personal Area
VehicularUrban
Fixed urban
User data rate
10 Mbps0.1
IEEE802.16a,d
1 100
HSDPAIEEE
802.16eNomadic
WLAN(IEEE 802.11x)
GSMGPRS
DECT
bluetooth
3G/WCDMA
EDGE
FlashOFDM (802.20)
Wireless Technology PositioningWireless Technology Positioning
3Communication Networks, Aachen University (RWTH)
Facts in Communication Networks and ProtocolsFacts 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
4Communication Networks, Aachen University (RWTH)
Status and future research funds in ComNets‘ working Status and future research funds in ComNets‘ working domain: Network Design and Evaluation Researchdomain: 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
Download Statistics from 1/2001 to 10/2005Download Statistics from 1/2001 to 10/2005
0
2000
4000
6000
8000
10000
12000
14000
Total number of documents downloaded: 84.681 Average of 1435 downloads/month
6Communication Networks, Aachen University (RWTH)
3072 154 163 185 206 221 224 227 228 253 255 325 340 379 382 384 443 509 664 678 750 792 803
1380
6626 18083US: United States (47,93%)
DE: Germany (17,56%)
CN: China (3,66%)
JP: Japan (2,13%)
GB: United Kingdom (2,1%)
KR: Korea (1,99%)
IN: India (1,8%)
FR: France (1,76%)
IT: Italy (1,35%)
TW: Taiwan (1,17%)
CA: Canada (1,02%)
AU: Australia (1,01%)
ES: Spain (1%)
NL: Netherlands (0,9%)
SE: Sweden (0,86%)
GR: Greece (0,68%)
FI: Finland (0,67%)
AT: Austria (0,6%)
BR: Brazil (0,6%)
ID: Indonesia (0,59%)
CH: Switzerland (0,59%)
PL: Poland (0,55%)
RU: Russian Federation (0,49%)
UA: Ukraine (0,43%)
MY: Malaysia (0,41%)
others (6,66%)
Paper Downloads by Country in 2005Paper Downloads by Country in 2005
7Communication Networks, Aachen University (RWTH)
Einordnung ComNets/MobNetsEinordnung ComNets/MobNets
Prozessoren, Chips, Bauelemente,Platinen, USB Stick,usw.
PC, Server,Mobile Phone,Funkstrecke,Lokales Netz,Motor/Umformer,Transformator,Elektrofahrzeug
Internet, Mobilfunknetz,Glasfasernetz, Hochregallager,Automatisierte Fertigung,Fabrik, Airbus, Transrapid
ComNets/MobNets Research/Teaching
SMS, MMS,Google/YahooNavigation,Steuerungssoftwarefür komplexe Platt-formen und Systeme,Middleware & embeddedSoftware
Technologien und Plattformen: Produktion/Entwicklung wandern tendenziell in Weltregionen mit geringen Lohnstückkosten aus.
Schaltungstechnik
8Communication Networks, Aachen University (RWTH)
Multimedia Internet Service PlatformMultimedia Internet Service Platform
Zugriff
Zugriff Zugriff
Servers
Anwender
Vermittlungsnetz
Kommunikation Steuerung
Inhalt Inhalt
9Communication Networks, Aachen University (RWTH)
Layered structure:
Link level…focussing the radio transmission
System level…focussing the entire network behaviour
Protocol level…focussing radio network protocols
22337
6655
441
readingreadingpacket call
ComNets ComNets Simulation ConceptsSimulation Concepts
10Communication Networks, Aachen University (RWTH)
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))
SourceSource
ScrambleScramble
RS EncodeRS Encode
Conv. EncodeConv. Encode
PuncturePuncture
ByteIntleaveByteIntleave
Bit-IntleaveBit-Intleave
ModulateModulate
SinkSink
DescrambleDescramble
RS DecodeRS Decode
Conv. DecodeConv. Decode
DepunctureDepuncture
ByteDeintleaveByteDeintleave
Bit-DeintleaveBit-Deintleave
DemodulateDemodulate
EqualEqual
Pilot InsertPilot Insert
Preamble Preamble InsertInsert
IFFTIFFT
CP AppendCP Append
ChannelChannel
Pilot ExracttPilot Exractt
FFTFFT
CP RemoveCP Remove
Preamble ExtractPreamble Extract
Ch
an
nel
C
ha
nn
el
Est
ima
teE
stim
ate
*SUI=Standford University Interim (for outdoors morpho)
11Communication Networks, Aachen University (RWTH)
System Level SimulationsSystem 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
12Communication Networks, Aachen University (RWTH)
Protocol Level Simulation: ParametersProtocol 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
13Communication Networks, Aachen University (RWTH)
Leistungsbewertung: SimulationsumgebungLeistungsbewertung: Simulationsumgebung
Um
statistische Auswertung
Momente
LRE PDF/CDF Histogramm
Mobilstation
Protokollmodell
Modellstochastisches
Basisstation
SMTP FTPStatus AVLSprache HTTP MM
Lastgenerator
UDPTCPIP
WTPWAP
Instanz
KanalmodellBU TU RA HT
LLC
MAC
PHY
LLC
MAC
PHY
14Communication Networks, Aachen University (RWTH)
Netz-ArchitekturNetz-Architektur für GSM und den für GSM und den General Packet Radio Service (GPRS)General Packet Radio Service (GPRS)
15Communication Networks, Aachen University (RWTH)
GSM/GPRS Protokoll-StapelGSM/GPRS Protokoll-Stapel
PHY
MAC
RLC
LLC
SNDCP
IP
UDP/TCP
Anwendung
PHY
MAC
RLC
L1bis
NetzDienste
BSSGP
L1bis
NetzDienste
BSSGP
L1
L2
IP
LLC
SNDCP
UDP/TCP
GTP
L1
L2
IP
UDP/TCP
GTP
IP IP
L2
L1
IP
L2
L1
UDP/TCP
Anwendung
MS BSS SGSN GGSN HostUm Gb Gn Gi
detailgetreumodelliert
vereinfachtesModell
16Communication Networks, Aachen University (RWTH)
Wartenetz Modell und Anwendung zur Modellierung Wartenetz Modell und Anwendung zur Modellierung eines Teilnehmer-Rechensystemseines Teilnehmer-Rechensystems
Stationi
Stationj
xni
nj
i
q ij x jK StationenN Aufträge
q q q q0i 0j i0 j0
EIN AUSgeschlossen
Auftragsverkehrslast Abgangsrate X0
Zentrales Teilnetz
K Stationen N Aufträge (O < N < M)
TerminalTeilnetz
M TerminalsZ Denkzeit
x0
EIN AUSEINAUS
qij = Übergangsraten Matrix
- stationsspezifische Bedienstrategie
- Wartepuffer mit Prioritäten
- Ergebnisse: P(Nj = nj); Wartezeitverteilung Stationsauslastung Durchsatz pro Auftragsklasse usw.
17Communication Networks, Aachen University (RWTH)
Modellierung: Quelle für Sprachpakete über GPRSModellierung: Quelle für Sprachpakete über GPRS
Aktive Phase Inaktive Phase
t
Paketgröße
24 byte
SID Paket
4 byte
Übertragungskanal
FCFS
RR
λ1
λi
λN
Modell der Verkehrsquelle
Wartemodell mit stochastischen Ankunfts- und Bedienprozessen und Bedienstrategie
18Communication Networks, Aachen University (RWTH)
Zustands-Übergangsdiagramm einer Markov Kette Zustand= aktive Sprachquellen N(t)=i, Pufferbelegung
222
21
220
12
11
10
202
01
2inaktivbleibt Quelle00
2
2
aktivbleibtQuelle
inaktivwirdQuelleaktivbleibtQuelle
inaktivwirdQuelle
aktivwirdQuelleaktivbleibtQuelle
aktivwirdQuelleinaktivwirdQuelleinaktivbleibtQuelleaktivbleibtQuelle
inaktivbleibtQuelleinaktivwirdQuelle
aktivwirdQuelle
aktivwirdQuelleinaktivbleibtQuelle
pp
ppp
pp
ppp
ppppp
ppp
pp
ppp
pp
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:
0,i
1,i
2,i
0,i-1
1,i-1
2,i-1
0,i-2
1,i-2
2,i-2
0,i-3
1,i-3
2,i-3
0,i+1
1,i+1
2,i+1
0,0
1,0
2,0
0,NQ
1,NQ
2,NQ
p00
p01
p02
p10
p11
p12
p22
p21
p21
Zustand: i,j
i = aktive Sprachquellen
j = Pakete im Puffer
19Communication Networks, Aachen University (RWTH)
Mathematische Verkehrsleistungs-Analyse für GPRS SpracheMathematische Verkehrsleistungs-Analyse für GPRS Sprache
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 20 40 60 80 100
Warteschlangenlänge (x)
P(X
>x)
Simulated
Calculated
500ms1 s
1.5 s
2 s
Komplementäre Verteilungsfunktion der Warteschlangenlänge für verschiedene mittlere Sprach-Phasenlängen (mittlere Sprachpausenlänge =1 s)
95-Perzentil der Wartezeit von Sprachpaketen bei 10 Sprachquellen
0
100
200
300
400
500
600
700
800
0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9
Mittelwert der Sprachpausenlänge [s]
95-P
erze
nti
l d
er W
arte
zeit
Calculated
Simulated
500 ms
750 ms
1000 ms
1500 ms
20Communication Networks, Aachen University (RWTH)
UMTS (2000): System Throughput & BER UMTS (2000): System Throughput & BER
Maximum System Throughput for WWW traffic reached with 64 kbit/s DTCH
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.2 0.4 0.6 0.8 1Block Error Probability
No. of Mobile Stations = 10No. of Mobile Stations = 30No. of Mobile Stations = 60No. of Mobile Stations = 100No. of Mobile Stations = 150No. of Mobile Stations = 200No. of Mobile Stations = 250
Block Error Rate at 256 kbit/s
the BLER increases with increased Number of Stations, reducing throuphput accordingly.
21Communication Networks, Aachen University (RWTH)
Cell Capacity over Distance Cell Capacity over Distance is Inverse to the Needsis Inverse to the Needs
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
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
New Deployment Concepts required tobring 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
Sources: B. Walke, H. Wijaya, D.C. Schultz: The Application of Relays in Infrastructure-based Future Mobile Radio Network Deployment ConceptsSubmitted: VTC 2006 Spring, Melbourne, AustraliaT. 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
Actual Available Capacity vs. Requested Capacity
Available
2005
Cell border
Cap
city
/A
rea
Ele
men
t
2010
Location of Base Station
Distance d
Requested by users
Users
at d
istan
ce d
22Communication Networks, Aachen University (RWTH)
Relay Enhanced Cells (REC)Relay Enhanced Cells (REC)Using Fixed Relay Stations (FRS)Using Fixed Relay Stations (FRS)
Pros:• Relays in REC
– don’t need a wired backbone access (lowers CAPEX and OPEX)
– 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– Exploitation of macro-diversity
(co-operative relaying)
Cons:• In band relays consume radio resources • Out of band relays need multiple transceivers • Relays introduce extra delay
AP
FRS
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
23Communication Networks, Aachen University (RWTH)
1. 2. 3.
Line of Sight
AP
Cellular Multi-hop deployment in highly shadowed environmentCellular Multi-hop deployment in highly shadowed environment
Channel Group 1Channel Group 2
Source: ComNets 2003
24Communication Networks, Aachen University (RWTH)
Capacity at Relay (FRS) with Antenna GainCapacity at Relay (FRS) with Antenna Gain
• 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)
FRS 1
FRS 2
FRS 3
FRS 4 AP
0 5 10 15 20 25 30 35 400
5
10
15
20
25
FRS receive antenna gain (dBi)
cap
acit
y (
Mb
it/s
)
FRS sub-cell
AP sub-cell
6.67 Mbit/s
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.
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.
25Communication Networks, Aachen University (RWTH)
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
ComNets Vision of a Mobile Low Cost Internet Access: ComNets Vision of a Mobile Low Cost Internet Access: Relay-based Cellular Wireless Mobile Broadband SystemRelay-based Cellular Wireless Mobile Broadband System
Access Point
1. Hop Relay
2. Hop Relay
Relay Enhanced Cell
26Communication Networks, Aachen University (RWTH)
f 1 f 3 f 7 f 9
f 4f 6 f 2
f 7 f 9
f 1
f 1
f 11
f 3
f 2
f 0f 10
f 10
f 8f 6
f 4
f 8
f 0
f 5
f 9
R
R
h h
f 5
f 5
f 5
f 5
f 5
i
i
j
i
j
i
i
j
j
i
j
j D1
D2
D3
D4
D5
D6
Reuse shift parameter for a Reuse shift parameter for a N N = 12 Relay-Cell cluster= 12 Relay-Cell clusterand Cell Radius Rand Cell Radius R
FMTAP Antenna
27Communication Networks, Aachen University (RWTH)
Single-Hop and Relay Enhanced Cell Throughput Single-Hop and Relay Enhanced Cell Throughput compared (3 FRS)compared (3 FRS)
Entfernung AP und M
T (x) [m
]
En
d-z
u-E
nd
e-D
urc
hsa
tz [
Mb
it/s]
Entfernung AP und MT (y) [m]
600400
2000
-200-400
-600
10
20
30
40
600400
2000
-200-400
-600
End
e-zu
-End
e-D
urch
satz
[Mbi
t/s]
-400
-200
0
200
400
-400
-200
0
200
400
0
5
10
15
20
25
30
AP
FMT
FMT
-400
-200
0
200
400
x
-400-2000200400y
2428
30
20161412
2Mbit/s
4Mbit/s
6Mbit/s
10Mbit/s
12Mbit/s
8Mbit/s
200m central cell
346m single hop cell
Area=
200m
200m
Iso-throughput curvesIso-throughput curves
Esseling, Norbert: Ein Relaiskonzept für das hochbitratige drahtlose lokale Netz HIPERLAN/2, ABMT 42, 1. Auflage Jul/2004, 307 Seiten, ISBN: 3-86130-169-5www.comnets.rwth-aachen.de/Dissertati.178.0.html
28Communication Networks, Aachen University (RWTH)
End-to-End Throughput DownlinkEnd-to-End Throughput Downlinkalong y-Axisalong y-Axis
y
3er, 3FMTs12er (346m)7er (346m)3er (346m)3er (200m)
0
5
10
15
20
25
30
35
40
12er (346m), kein FMT
45
0 50 100 150 200 250 300 350 400
12er
7er3er
1.Hop
1.Hop
1.Hop
2.Hop2.Hop 2.Hop
End
-to-
End
Thr
ough
put [
Mbi
t/s]
Distance [m]
3er, Relais-Sys.>1-Hop-Sys.
7er, Relais-Sys.>1-Hop-Sys.
12er, Relais-Sys.>1-Hop-Sys.
7er (346m), kein FMT3er (346m), kein FMT
12er, 3FMTs7er, 3FMTs
29Communication Networks, Aachen University (RWTH)
Single-Hop and Relay Enhanced Cell Throughput Single-Hop and Relay Enhanced Cell Throughput compared (3 FRS)compared (3 FRS)
Entfernung AP und M
T (x) [m
]
En
d-z
u-E
nd
e-D
urc
hsa
tz [
Mb
it/s]
Entfernung AP und MT (y) [m]
600400
2000
-200-400
-600
10
20
30
40
600400
2000
-200-400
-600
End
e-zu
-End
e-D
urch
satz
[Mbi
t/s]
-400
-200
0
200
400
-400
-200
0
200
400
0
5
10
15
20
25
30
AP
FMT
FMT
-400
-200
0
200
400
x
-400-2000200400y
2428
30
20161412
2Mbit/s
4Mbit/s
6Mbit/s
10Mbit/s
12Mbit/s
8Mbit/s
200m central cell
346m single hop cell
Area=
200m
200m
Iso-throughput curvesIso-throughput curves
Esseling, Norbert: Ein Relaiskonzept für das hoch bitratige drahtlose lokale Netz HIPERLAN/2, ABMT 42, 1. Auflage Jul/2004, 307 Seiten, ISBN: 3-86130-169-5www.comnets.rwth-aachen.de/Dissertati.178.0.html
At 11,8 dbi
30Communication Networks, Aachen University (RWTH)
Multi-hop Relay TechnologiesMulti-hop Relay TechnologiesR.R. Pabst, B. Walke, D.C. Schultz:Pabst, B. Walke, D.C. Schultz:Relay-Based Deployment Concepts for Wireless and Mobile Broadband Relay-Based Deployment Concepts for Wireless and Mobile Broadband
RadioRadio. In . In IEEE Communications MagazineIEEE Communications Magazine, p.p. 80-89, New York, US, 09/2004, p.p. 80-89, New York, US, 09/2004
Time domain relay(FWR)
Frequency domain relay
Frequency domain relaywith pure forwarding
31Communication Networks, Aachen University (RWTH)
Forwarding Concept: Case 2Forwarding Concept: Case 2
MTs served by APMTs served by AP
MTs served by FRS#4MTs served by FRS#4
MTs served by FRS#3MTs served by FRS#3
FRS#4served by AP
FRS#4served by AP
FRS#3served by AP
FRS#3served by AP
MTs served by FRS#2MTs served by FRS#2
MTs served by FRS#1MTs served by FRS#1
Time
TMP-MTTAP-FRS
FRS#2served by AP
FRS#2served by AP
FRS#1served by AP
FRS#1served by AP
FRS 1
FRS 2
FRS 3
FRS 4 AP
TMP-MT
• One carrier frequency
• Exploitation of environment
2 Groups of FRSs that can serve their MTs in parallel
• One carrier frequency
• Exploitation of environment
2 Groups of FRSs that can serve their MTs in parallel
32Communication Networks, Aachen University (RWTH)
Coordination Across BSCoordination Across BSResource PartitioningResource Partitioning
MTs served by AP CMTs served by AP C
MTs served by FRS#C4MTs served by FRS#C4
MTs served by FRS#C3MTs served by FRS#C3
FRS#C4served by AP
FRS#C4served by AP
FRS#C3served by AP
FRS#C3served by AP
MTs served by FRS#C2MTs served by FRS#C2
MTs served by FRS#C1MTs served by FRS#C1
Time
TMP-MTTAP-FRS
FRS#C2served by AP
FRS#C2served by AP
FRS#C1served by AP
FRS#C1served by AP
TMP-MT
MTs served by AP BMTs served by AP B
MTs served by FRS#B4MTs served by FRS#B4
MTs served by FRS#B3MTs served by FRS#B3
FRS#B4served by AP
FRS#B4served by AP
FRS#B3served by AP
FRS#B3served by AP
MTs served by FRS#B2MTs served by FRS#B2
MTs served by FRS#B1MTs served by FRS#B1
FRS#B2served by AP
FRS#B2served by AP
FRS#B1served by AP
FRS#B1served by AP
MTs served by AP AMTs served by AP A
MTs served by FRS#A4MTs served by FRS#A4
MTs served by FRS#A3MTs served by FRS#A3
FRS#A4served by AP
FRS#A4served by AP
FRS#A3served by AP
FRS#A3served by AP
MTs served by FRS#A2MTs served by FRS#A2
MTs served by FRS#A1MTs served by FRS#A1
FRS#A2served by AP
FRS#A2served by AP
FRS#A1served by AP
FRS#A1served by APC
ell T
ype
AC
ell T
ype B
Cel
l Type
C
Time Slot to Feed FRSs Time Slot X Time Slot Y Time Slot Z
33Communication Networks, Aachen University (RWTH)
Coordination Across BSsCoordination Across BSs
• Only one Carrier Freq. Required to cover the scenario
• Distance between “co-channel” sub-cells: 460 m
• Only one Carrier Freq. Required to cover the scenario
• Distance between “co-channel” sub-cells: 460 m
FRS 1
FRS 2
FRS 3
AP
FRS 1
FRS 2
FRS 3
FRS 4 AP
FRS 1
FRS 2
FRS 3
FRS 4 AP
FRS 2
FRS 3
FRS 4 AP
FRS 1
FRS 2
FRS 3
FRS 4 AP
FRS 1
FRS 3
FRS 4 AP
FRS 4
FRS 3
FRS 1
FRS 2FRS 4 AP
FRS 2
FRS 1
Cell Type A
Cell Type B
Cell Type C
34Communication Networks, Aachen University (RWTH)
Mesh Network applied to IEEE 802.11 WLAN:Mesh Network applied to IEEE 802.11 WLAN:ComNets Proposal 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
MNIEEE802.11eMN
CFP CP
IEEE802.11eMN
CFP CP
• Coexistence of MN with IEEE 802.11e
Beacon Guard timeNote:
The guard times are fixedSource: 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 2004And: Wijaya, Harianto: Broadband Multi-Hop Communication in Homogeneous and Heterogeneous Wireless Lan NetworksABMT 46, 1. Auflage Feb/2005, 237 Seiten, ISBN: 3-86130-175-X, available at: www.comnets.rwth-aachen.de/Dissertati.178.0.html
35Communication Networks, Aachen University (RWTH)
Mesh Network (MN) and IEEE 802.16 combined.Mesh Network (MN) and IEEE 802.16 combined.ComNets proposes dedicated mesh network protocolComNets 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
MNIEEE802.16MN
Periodic Frame specific
IEEE802.16MN
Periodic Frame specific
Coexistence of MN with IEEE 802.16
Beacon Guard timeNote:
The guard times are fixedSource: 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
36Communication Networks, Aachen University (RWTH)
Possible IEEE 802.16 WiMAX Mesh SolutionPossible 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)
37Communication Networks, Aachen University (RWTH)
Coexisting WLANs: The Game ModelCoexisting WLANs: The Game Model
player
application
WLAN
supports
required QoSparameters
1..*
has a
QoS parameters
Delta (delay)Theta (throughput) Xi (jitter)
demanded QoSparameters
action
defines
takes into accountstrategy
behavior
determinesmutual
interferencewithin SSG
dependson
observed QoSparameters
leads to
payoff(outcome)
define
defineutility
determines
discountingfactor
long-term maximization
• 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
38Communication Networks, Aachen University (RWTH)
WLAN Spectrum Coexistence Scenario: WLAN Spectrum Coexistence Scenario: Two 802.11e QBSSs sharing one ChannelTwo 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
HCF 1Player 1
HCF 2Player 2
QSTAEDCF
Player 3represents offeredEDCF traffic within
the OQBSS
signals communicationand control
QSTA
QSTA
QSTA
QSTA
detection rangesof HCFs
QSTA: Quality Station
HCF: Hybrid Coordinator Function
39Communication Networks, Aachen University (RWTH)
Nash EquilibriumNash Equilibrium
payoff of player i: Vi(ai,a-i)
payoff of player -i: Vi(a-i,ai)
0.5
1
0.5
(C|C)
(D|C)
(D|D)
(C|D)
gain through deviation
punishment through opponent defection
1
player -i cooperatesplayer -i defects
payoff under coop-
eration
1.
2.Nash
Equilibrium
3.
0
player i’s classifications of opponent’s behavior
1.
Definition:
“No player can gain a higher
payoff in deviating from Nash
Equilibrium”
stable and thus predictable point of
interaction
player i defecting
player -i defecting
stable point of interaction
40Communication Networks, Aachen University (RWTH)
Strategies in Multi Stage Games (I)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
all outcomes except (C)
C
(C)
D
9090 9090
(*)
n=1
(2) GRIM
C
(C)
(D)D
90
9090
90
(D)9090
(C)
n=1
• Example: Dynamic trigger strategy TitForTat (TFT) – the player cooperates if the opponent cooperates and vice versa
C
(*)9090
n=1
(1) COOP (3) RANDOM
C
50%
50%D
90
9090
90
50%9090
50%
n=1
(4) TFT
41Communication Networks, Aachen University (RWTH)
Strategies in Multi Stage Games (II)Strategies in Multi Stage Games (II)
TFT versus various strategies
• Multi Stage Games of multiple strategies, evaluated in terms of observed throughput (Θ) and (TXOP) delay
• 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
RANDOM versus various strategies
42Communication Networks, Aachen University (RWTH)
ComNets Concept for a Flexible Protocol StackComNets Concept for a Flexible Protocol Stack
• 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
mode 1 mode x
system specific protocol stack
same property
(classic) single protocol stack
generic protocol stack
specific parts
common functionalityspecific functionality
mode 2protocol functions
protocol architecture
data structuresdifferent
protocol framework
protocol management
reconfiguration management/functions
multi-mode (composite) protocol stack
reconfigurable protocol stack
modes convergence management/functions
43Communication Networks, Aachen University (RWTH)
WINNER Multi-Mode Protocol WINNER Multi-Mode Protocol ArchitectureArchitecture
(2) management that is specifically optimized for the mode1 and mode2 in use probably more efficient
RRC-r2
ge
ne
ric
sta
ck
ma
na
ge
me
nt
MAC-r2
PHY-s2 PHY-r2PHY-s2
PHY-gPHY-g
PHY-r1
PHY-gMAC-g
MAC-r1
RLC-g
control-plane
RRC-r1
RRC-g
join
t m
od
e 1
/2 st
ack
m
an
age
me
nt
alternatives
control usermanagement
modes-switching
and coexistence
configuration and information transfer
reco
nfig
ura
tion
ma
na
ge
me
nt
Stack Management alternatively: (1) generic management more flexible
44Communication Networks, Aachen University (RWTH)
Reference Structure of Layer or SublayerReference Structure of Layer or Sublayer
L(N) - mode 1, 2 or 3
L(N) - SAP-s1.1
L(N-1) -SAP-s1.1
L(N) - SAP-s1.2
services of layer (N) / sublayer (N.n)
provided jointly through generic and
specific parts
(N)-MCM
(re)configures
composes L(N) – mode 1 – specific part
L(N) – mode 2 – specific part
L(N) – generic partfor mode 1-2-3convergence
L(N) – mode 3 – specific part
L(N) - SAP-s2.1
L(N) - SAP-s2.2
L(N) - SAP-s3.1
L(N-1) - SAP-s2.1
L(N-1) -SAP-s3.1
stack management
L(N) - SAP-g
L(N) - mode 1, 2 or 3
L(N) - SAP-s1.1
L(N-1) -SAP-s1.1
L(N) - SAP-s1.2
services of layer (N) / sublayer (N.n)
provided jointly through generic and
specific parts
(N)-MCM
(re)configures
composes L(N) – mode 1 – specific part
L(N) – mode 2 – specific part
L(N) – generic partfor mode 1-2-3convergence
L(N) – mode 3 – specific part
L(N) - SAP-s2.1
L(N) - SAP-s2.2
L(N) - SAP-s3.1
L(N-1) - SAP-s2.1
L(N-1) -SAP-s3.1
stack management
L(N) - SAP-g
(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
45Communication Networks, Aachen University (RWTH)
Realization of the Flexible Protocol StackRealization of the Flexible Protocol Stack
• 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
PHY
PHY
RLC
MAC
TCP/UDP / IP
PHY
Channel (Modem)
Stack Config.
data
data
Functional Modul
Functional Modul
Functional Unit
Functional Unit
Functional Unit
Mode Specific
(Sub-)layer Interface
(N)-Layer Configuration
Service Access Point
Service Access Point
Data
Composition, Parameterization and Data Query
modespecific
generic
Interface
RRC
46Communication Networks, Aachen University (RWTH)
Spectrum Requirement Estimation at a GlanceSpectrum Requirement Estimation at a Glance
Market info Calculation algorithm Radio technology info
Future services
Offered traffic
Required Quality of Service (QoS)
Scenarios definition
Traffic distributionto Radio Access
Techniques (RAT) & Radio Environments
Capacity dimensioning
Adjustments & weighting
Capabilities
Availability/ Coverage
Technical spectrum requirements
47Communication Networks, Aachen University (RWTH)
General Approach for Capacity CalculationGeneral Approach for Capacity Calculation
• In packet based systems QoS constraints require certain amount of free capacity
System Load
System Throughput Mean Delay
100%
PhysicalLayerThroughput
Delay Target
Usable fraction of system capacity
MACLayerThroughput
RLCLayerThroughput
overloadunderload
Tmax = Crlc System Load
48Communication Networks, Aachen University (RWTH)
βN, βN(2)
β1, β1(2)
Packet-switched Capacity CalculationPacket-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
λ2
λN
C
Priority 1
Priority 2
Priority N
Server
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
Highest priority
Lowest priority
β2, β2(2)
49Communication Networks, Aachen University (RWTH)
Aggregate Spectrum RequirementAggregate Spectrum Requirement
• 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
Required spectrum [MHz] Relative change [%]
Service environment
UL 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
50Communication Networks, Aachen University (RWTH)
Communication Networks (Walke): Communication Networks (Walke): “We do mostly layers 2..4”“We do mostly layers 2..4”
Transport Services & Protocols4
Radio Resource & Mobility 3 Control
Location Based Services3
Medium Access & Link Control 2 Protocols
Smart Antenna Protocol 1-2 Support B
road
ban
d W
irel
ess
Tra
nsp
ort
Pla
tfo
rms
Mesh
Netw
ks.
& R
ela
yin
g f
or
cellu
lar
Fix
ed
an
d M
ob
ile N
etw
ork
s
Con
verg
en
ce
IEEE 8
02.1
1/1
5/1
6/2
1
Sta
nd
ard
izati
on
Wir
ele
ss N
etw
ork
s &
In
terw
ork
ing
Sp
ectr
um
Co
-exi
sten
ce
Res
earc
h
Tra
ffic
Per
form
ance
E
valu
atio
n
(Th
eory
of
Lar
ge
Sys
tem
s)
Ad
apti
ve P
roto
col
Sta
ck
So
ftw
are
Communication Networks
ComNets ProfileComNets Profilehttp://http://www.comnets.rwth-aachen.dewww.comnets.rwth-aachen.de// (Oct. 2005)(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.
52Communication Networks, Aachen University (RWTH)
Comparison MobNets (left) and ComNets (right)Comparison MobNets (left) and ComNets (right)
Transport Protocobls4
Network Optimization & Theory3
Service Discovery3
Link Layer Protocols2
Cross Layer Issues &Low-Power1/2
Sen
sor
Net
wo
rks
and
A
pp
lica
tio
ns
Per
son
al A
rea
Net
wo
rks
Sel
f-C
on
fig
ura
tio
n (
ad
ho
c)W
irel
ess
LA
Ns
Ad
van
ced
Cel
lula
r N
etw
ork
sC
og
nit
ive
Rad
ios
and
N
etw
ork
s
Transport Services & Protocols4
Radio Resource & Mobility 3 Control
Location Based Services3
Medium Access & Link Control 2 Protocols
Smart Antenna Protocol 1-2 Support
Bro
adb
and
Wir
eles
s T
ran
spo
rt
Pla
tfo
rms
Mes
h N
etw
ork
s &
Rel
ayin
g f
or
Cel
lula
rIE
EE
802
.11/
15/1
6/21
S
tan
dar
diz
atio
nS
pec
tru
m C
o-e
xist
ence
R
esea
rch
Tra
ffic
Per
form
ance
E
valu
atio
n
Ad
apti
ve P
roto
col
Sta
ck
So
ftw
are
53Communication Networks, Aachen University (RWTH)
Courses, Labs and SeminarsCourses, 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
54Communication Networks, Aachen University (RWTH)
Curriculum lecture, Labs, Seminars Type Credits ResponsiblesET&IT u. TI Grundgebiete der Informatik 3 Mandat V2 Ü1 Walke u. wiss. Mitarb.ET & IT u. TI Praktikum Grundgeb. Informatik 1 MandatP4 Walke/Kraiss und wiMi
TI und ET & IT Komm.Netze u. Verkehrstheorie MandatV4 Ü2 Walke u. wiss. Mitarb. TI und ET & IT Praktikum Kommunikationsnetze Elective P4 Walke u. wiss. Mitarb.
ET & IT Praktikum Mobilfunknetze Elective P3/4 Walke u. wiss. Mitarb. ET & IT Seminar Kommunikationsnetze Elective V3 Walke u. wiss. Mitarb.
TI und ET & IT Stochastische Simulationstechnik CatalogV4 Ü2 Walke/jetzt LehrauftragTI und ET & IT Praktikum Stochast.Simulationstechnik Elective P3/4 Walke u. wiss. Mitarb. Techn. Inform. Einführung: Objektorient. Programmierg. Mandat P3 Walke/Gebhardt u.a.Techn. Inform. Projekt CORBA Elective V4 Walke u. wiss. Mitarb.
Courses, Labs and Seminars by ComNets Current (stationary) Status
55Communication Networks, Aachen University (RWTH)
Proposal for Call for ApplicationsProposal 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
56Communication Networks, Aachen University (RWTH)
Wesentliche Ergebnisse in 2004Wesentliche 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
57Communication Networks, Aachen University (RWTH)
Ende
Top Related