Transcript Satellite Next Generation Networks : QoS issues

Satellites in Next Generation Networks
QoS issues
Stéphane Combes, R&D, Alcatel Space
ITU-T workshop on Satellites in IP
and Multimedia
Geneva, 9-11 December 2002
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 — 2
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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 — 3
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NGN
End-to-End QoS
Home
Network
Home
Network
Applic.
Applic.
QoS
Selection
SIP
S-CSCF
SIP
SIP
Access
Network
SIP
3
S-CSCF
QoS 4
Negotiation
SIP
SIP
P-CSCF
Bearer
setup
End
User
P-CSCF
5
Visited
Network
5
Core
Network
Originating side
Satellite NGN : QoS issues — 4
QoS
Selection
2
1
End
User
SIP
Bearer
setup
Visited
Network
Terminating side
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Access
Network
NGN
General Layered QoS Model
Application Layer
QoS info
QoS info
Session Layer
URI
URI
URI
QoS info
QoS info
QoS info
QoS info
end
user
QoS info
Connection Control Layer
End
IP @
End IP @
End IP @
QoS info
QoS info
QoS info
QoS info
Transport Layer
Hop
routing
Hop
routing
Hop
routing
end
user
Session Layer
SIP
P-CSCF
End
IP @
COPS
Hop
routing
Connection Layer
PCF
ARC
AC
COPS
End
User
Satellite NGN : QoS issues — 5
Access
Network
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AG
Transport Layer
Core
Network
Current Satellite Systems
Access 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
Satellite
O n Board Processor
(cell or circuit switching )
> 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 — 6
Signalling link
Interactive
Network j
MNMS
LAN
Access
Network
Management
ST
ISP
Corporate
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Signalling link
ST
Traffic link
ISP
NCC i
Corporate
ST
Interactive
Network i
Access
Control
functions for
Interactive
Network i
ST
ST
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 — 7
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Enhancing the current situation
Expected 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 — 8
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Enhancing the current situation
Star Architecture
Application
SERVICE PROVIDER
PDP
CDRs on ###
AAA
Session protocol
Call Server
+Transport PDP
SIP
Network transport
Policy control
protocol
ST
Call
HUB
SIP
Call Signalling
M e d ia f lo w
Endpoint
AG
RSVP QoS Signalling
Call
Forwarding
QoS Signalling
AG
RSVP
C o n n e c t io n
COPS
S ig n a llin g
Network transport
QoS protocol
QoS Signalling
NCC
Connection Signalling
Transport PEP
DAMA
Satellite transport
QoS protocol
(DVB-RCS
extension)
Satellite NGN : QoS issues — 9
proxy
AG
CDRs on
TRANSPORT PROVIDER
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IP@
Endpoint
Enhancing the current situation
Mesh architecture
Application
SERVICE PROVIDER
PDP
CDRs on ###
AAA
Call
Server
+ Transport PDP
ST
HUB
SIP
Call
Endpoint
Call Signalling
Forwarding
RSVP
COPS
AG
QoS Signalling
QoS Signalling
M e d ia f lo w
RSVP
ST
NCC
SIP
Call
Endpoint
AG
RSVP
Transport PEP
DAMA
LPDP
proxy
AG
Connection Signalling
CDRs on
TRANSPORT PROVIDER
Satellite NGN : QoS issues — 10
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IP@
Satellite in NGN
Status
> 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 — 11
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Satellite in NGN
Future 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
Satellite NGN : QoS issues — 12
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