itu-t workshop on satellites in ip and multimedia geneva, 9-11 december 2002 satellites in next...
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ITU-T workshop on Satellites in IP and Multimedia Geneva, 9-11 December 2002
Satellites in Next Generation NetworksQoS issuesStéphane Combes, R&D, Alcatel Space
Satellite NGN : QoS issues — 2 All rights reserved © 2002, Alcatel Space
Content
> What NGN and QoS mean ? End-to-end QoS - Layered model
> Current Satellite Systems Access network architectures- QoS
> Enhancing the current situation Expected improvement- Architectures
> Satellite in NGN- Status- Future Activities
Satellite NGN : QoS issues — 3 All rights reserved © 2002, Alcatel Space
NGN In Short
> NGN (Next Generation Networks) means Uncoupling services and transport provision (like IN) Multimedia/multi-services/multi-networks Packet-based (IP) QoS and security are MUST !
> QoS for NGN means QoS aware network equipment Admission control mechanisms Interaction between call signalling, resources
management and admission control
Satellite NGN : QoS issues — 4 All rights reserved © 2002, Alcatel Space
NGN End-to-End QoS
Access Network
SIP
SIP
End User
SIP
Home Network
Visited Network
Applic.
1
QoS Selection
S-CSCF
P-CSCF
Core Network
Originating side Terminating side
SIP2
Applic.
S-CSCF
Home Network
SIP
SIPSIP
End User
Access Network
Visited Network
3
QoS Selection
P-CSCF
4QoS Negotiation
55
Bearer setup
Bearer setup
Satellite NGN : QoS issues — 5 All rights reserved © 2002, Alcatel Space
NGN General Layered QoS Model
Session Layer
Connection Control Layer
Transport Layer
URIURI
End IP @ End IP @
Hop
routing
Hop
routing
Hop
routing
Hop
routing
EndIP @
EndIP @
QoS info
QoS infoQoS info
QoS infoQoS info
QoS infoQoS info
QoS infoURI
QoS info
Application Layer
QoS infoQoS info
enduser
enduser
Core Network
Access Network
SIP
AGEnd User
P-CSCF
AC
COPS
Session Layer
Transport Layer
Connection Layer
COPS
PCF
ARC
Satellite NGN : QoS issues — 6 All rights reserved © 2002, Alcatel Space
Current Satellite SystemsAccess Network Architectures
> DVB-RCS architecture 2-way multimedia IP based DVB-S forward link MF-TDMA return link ATM or MPEG
segmentation Packet based DAMA
Corporate
RAS
SatelliteTerminal (ST)
Telcos
Transportnetwork
ISPs
HUB
Return link
Return linkMF-TDMA ATM orMPEG
Forward linkTDM DVB-S
STLAN
LAN
ST AccessNode
ManagementCentre
RMG
SME/Enterprise
ISP POP
Multi-Dwelling
Telco POP
LAN
SOHO/RES
PSTN
LANLAN
NCC i
C o rpo ra te
ST
A ccessN etwo rk
M a na g em entISP
M NM S
Tra ffi c link
Sig na lling link
LA N
ST
ST
Sa telliteO n Bo a rd Pro cesso r
(cell o r circuit sw itch ing )
A ccessC o ntro l
functio ns fo rIn tera ctiveN etwo rk i
C o rpo ra te
ISP
ST
Sig na lling link
STInteractiveNetw ork i
InteractiveNetw ork j
> Regenerative Satellite architecture Multi-Gateway Mesh: direct ST-to-ST ATM or MPEG on-board switching DVB-S downlink DVB-RCS uplink
Satellite NGN : QoS issues — 7 All rights reserved © 2002, Alcatel Space
Current Satellite Systems QoS> Service Level Agreement (SLA)
Satellite network operator grants a given bandwidth (usually constant) to each service provider for its pool of STs
Service providers grant subscribers a per ST traffic contract:
– Best effort with peak rate– Minimum guaranteed rate with a peak rate
> Static Admission Control At ST log-on Upon management action
> Traffic Contract Enforcement Return link: DAMA algorithms using capacity categories
defined in DVB-RCS: CRA, RBDC, VBDC, FCA Forward link: IP and/or ATM traffic management (policy,
shaping) in the Hub
Satellite NGN : QoS issues — 8 All rights reserved © 2002, Alcatel Space
Enhancing the current situationExpected improvements
> STEP 1 - Adding flexibility & better QoS in the access Priority mechanisms between Real-Time and non Real-
Time applications according to IP CoS indications (DiffServ DSCP)
Coupling between IP and MAC processes in ST Traffic contract modification of the ST from NMC or upon
user’s request (e.g. using a Web-based interface)
> STEP 2 - Interworking between access and core NGN enabled networks Dynamic admission control based on specific satellite
signalling mechanisms Dynamic admission control and resource reservation
coupled with call signalling protocols (SIP, H323)
Satellite NGN : QoS issues — 9 All rights reserved © 2002, Alcatel Space
Enhancing the current situation Star Architecture
Call
Endpoint
Call S erver
S T H UB
Forwarding
A pplicat ion
PDP
A A A
T RA N S PO RT PRO VI DER
S ERVI CE PRO VI DER
Call
Endpoint
Call S ignalling
Q oS S ignalling
Q oS S ignalling
CDRs on # # #
CDRs on
I P@
Connect ion S ignalling
Connect ion
S ignalling
M edia fl ow
RS VP
S I P
Q oS S ignalling
CO PS
N CC
T ransport PEP
proxyAG
DA M A
S I P
RS VPAGAG
+T ransport PDP
Session protocol
Network transport
QoS protocol
Satellite transportQoS protocol
(DVB-RCS extension)
Network transport
Policy control protocol
Satellite NGN : QoS issues — 10 All rights reserved © 2002, Alcatel Space
Enhancing the current situation Mesh architecture
Call
Endpoint
Call S erver
S TH UB
Forwarding
A pplicat ion
PDP
A A A
T RA N S PO RT PRO VI DER
S ERVI CE PRO VI DER
Call S ignalling
Q oS S ignalling
CDRs on # # #
CDRs on
I P@
Connect ion S ignalling
M edia fl ow RS VP
S I P
Q oS S ignalling
CO PS
N CC
T ransport PEP
LPDPDA M ACall
Endpoint
S T S I P
proxy AG
AG
AG
RS VP
RS VP
+ T ransport PDP
Satellite NGN : QoS issues — 11 All rights reserved © 2002, Alcatel Space
Satellite in NGNStatus
> Current NGN-related terrestrial network activity is huge Standards : IETF, ITU, ETSI Planned roll-out for Cable, UMTS and DSL access
networks
> Satellite system is weak in NGN picture Only pure physical/access layer standards (DVB-RCS) No QoS support definition No satellite/terrestrial interworking defined Current proprietary solutions and weak QoS May slow down the up-taking of NGN and their
associated services through satellite
Satellite NGN : QoS issues — 12 All rights reserved © 2002, Alcatel Space
Satellite in NGNFuture Activities> Determine typical applications/services scenarios
requiring QoS support and their requirements for integration of Broadband Multimedia systems
> Define QoS architectures, identify functional entities and interfaces. Analyse call signalling/resources management/ admission control interactions
> Guarantee interoperability with terrestrial NGN protocols or propose extensions/profiles. Analyse specific processing or adaptations required in satellite access equipment at adaptation & access layers
> Propose potential extensions or adaptations to satellite access standards such as DVB-RCS : transparent +OBP based meshed systems