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Workshop on Broadband Wireless Ad-Hoc Networks and Services, 12th - 13th September 2002, ETSI, Sophia Antipolis, France. QoS Provisioning in IP-based Broadband Wireless Mobile Networks. A. H. Aghvami and Bongkyo Moon Centre for Telecommunications Research King’s College London - PowerPoint PPT Presentation
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QoS Provisioning in IP-based Broadband Wireless Mobile Networks
Workshop on Broadband Wireless Ad-Hoc Networks and Services, 12th - 13th September 2002,
ETSI, Sophia Antipolis, France
A. H. Aghvami and Bongkyo Moon
Centre for Telecommunications Research
King’s College London
E-mail: {hamid.aghvami, bongkyo.moon}@kcl.ac.uk
Outline
RSVP under IP Micro Mobility Protocol
Proposed RSVP-based QoS Mechanism
RSVP Branch Path Rerouting Determination of Crossover Router under IP micro mobility
RSVP Branch Path Rerouting at Crossover Router (CR)
Seamless Switching of RSVP Branch Path RSVP Branch Path Reservation in advance for Soft Handoff
Switching of RSVP Branch Path for Soft Handoff
Results
Conclusions
Wireless Bandwidth Restrictions
- RSVP allows Internet real-time applications to reserve resources before they start transmitting data.
- Many RSVP flows cause a lot of control information over wireless link
- RSVP reservation refresh messages need not be sent as often on the wireless link
- Efficient wireless bandwidth management scheme is required
RSVP Issues under IP micro-mobility (1)
Mobility
- Whenever a MN performs a handoff, RSVP signaling process must be invoked immediately to discover the new path to the MN from the CN
- However, long resource reservation delay may occur during re-establishment of a flow after handoff under RSVP
- Service disruptions could occur in providing real-time services under RSVP and mobility.
- need to make resource reservations in advance along the paths to the neighboring BSs
RSVP Issues under IP micro-mobility (2)
RSVP-enabled router in IP micro mobility
RSVP-enabled Router
RSRR Interface
Forwarding database
Routing daemon
RSVP daemon
RSVP State Information
PATHRESV
DATA
PATHRESV
DATA
...
PATHRESV
DATA
PATHRESV
DATA
...RSVP-enabled Router
RSRR Interface
Forwarding databaseForwarding database
Routing daemonRouting daemon
RSVP daemonRSVP daemon
RSVP State Information
PATHRESV
DATA
PATHRESV
DATA
...
PATHRESV
DATA
PATHRESV
PATHRESV
DATADATA
PATHRESV
DATA
PATHRESV
PATHRESV
DATADATA
...
PATHRESV
DATA
PATHRESV
DATA
...
PATHRESV
PATHRESV
DATADATA
PATHRESV
PATHRESV
DATADATA
...
Mobile node (MN) moves into soft handoff zone
Pilot signal strength from a new BS ≥ TRSVP
Mobile node keeps on-going flow without special action
MN is a sender ?
Send RSVP PATH message along the new BS toward GW
Determine the location of a crossover router (CR) in IP mobility networks
CR is a receiver ?
Send a route update message along the new BS toward GW
RSVP daemon on the CR immediately sends an RESV message toward the MN
BS receives an RESV message, and then executes resource allocation algorithm over wireless link to reserve resource
RSVP daemon on the CR immediately triggers a PATH message toward the MN
MN sends RESV message toward the intended receiver
Yes
No
Yes
Yes
No
No
RSVP reservation is completed within threshold time ?
QoS disruption
QoS guaranteed
Soft handoff initiates with RSVP reservation along the new path by switching RSVP branch path successfully
Yes
No
Proposed RSVP-based QoS Mechanism
RSVP Branch Path RSVP Branch Path Rerouting under IP Rerouting under IP Micro Mobility ProtocolMicro Mobility Protocol
- In the case an MN is a sender, an RSVP PATH message
is sent by an MN after the route update is completed. - When the RSVP daemon on the CR receives an RSVP
PATH message after a mobility event, it immediately
sends an RSVP RESV message to an MN without
delivering to the original receiver.
- In the case an MN is a receiver, the RSVP daemon on
the CR can trigger an RSVP PATH message immediately
when detecting any changes to the stored PATH state or
receiving a PCN message from the underlying routing
daemon.
Determination of Crossover Router
- Having multiple hops for a RSVP connection => more links are utilized and this increases the network congestion and resource reservation failure
- shorter hops and circuit reuse should be considered during RSVP path rerouting
- RSVP path re-establishment time depends on the number of hops required in rerouting the RSVP partial branch path, a crossover router(CR) dependent.
- branch path rerouting at CR in tree topology guarantees the minimum path change and the shortest path
Rerouting of Branch Path at CR
RSVP Branch Path Rerouting in a Tree
Internet
Gateway (GW)
Crossover Router (CR)
MN
CR
RSVP Path Rerouting Signaling at CR
MN AR (BS) CR GW
route updateroute update
route update
PATHPATH
RESV
RESV
MN AR (BS) CR GW
route update &
PATH route update &
PATH route update
RESV
RESV
- MN is a sender
- MN is a receiver
Seamless Switching of Seamless Switching of RSVP Branch Path under RSVP Branch Path under IP Micro Mobility IP Micro Mobility ProtocolProtocol
Access Router A
Pilot Strength
TADD
TRSVP
TDROP
Distance
RSVP Reservation Request along the
new Path via BS ‘B’
Soft handoff Initiation with RSVP Reservation
along the new Path
RSVP Path Preparation Zone (S)
Access Router B
Soft Handoff Zone
Handoff Drop Timer
RSVP Path Reservation for Soft Handoff
CN
GW
MN
CR
Internet
BS ‘A’ BS ‘B’
Original RSVP reservation path of the flow
Branch path added newly during soft handoff
Switching of RSVP Branch Path (1)
IP Micro Mobility Networks
Original RSVP reservation path of the flow
Branch path added newly during soft handoff
Crossover Router
Gateway Router
Access Router
CN
Switching of RSVP Branch Path (2)
Number of Levels in a Tree
2 3 4 5
Pro
babi
lity
of
Ser
vice
Dis
rupt
ion
0.2
0.4
0.6
0.8
0.0
1.0TRSVP = -13.1 dB
TRSVP = -13.5 dB
TRSVP = -13.6 dB
TRSVP = -13.3 dB
Various TRSVP under V =9.0 m/s and high load.
Probability of Service Disruption (1)
Number of Levels in a Tree
2 3 4 5
Pro
babi
lity
of
Ser
vice
Dis
rupt
ion
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
V = 6 m/s
V = 8 m/s
V = 10 m/s
V =12 m/s
MN’s various velocity under TRSVP = -13.4 dB and high load
Probability of Service Disruption (2)
Number of Levels in a Tree
2 3 4 5
Pro
babi
lity
of
Ser
vice
Dis
rupt
ion
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Low Load
Medium Load
High Load
Various load condition under V =10.0 m/s and TRSVP = -13.3 dB
Probability of Service Disruption (3)
Number of Levels in a Tree
2 3 4 5
Mea
n N
umbe
r of
Los
t Pac
kets
0
5000
10000
15000
20000
25000
30000TRSVP = -13.1 dB
TRSVP = -13.5 dB
TRSVP = -13.3 dB
TRSVP = -13.6 dB
Various TRSVP under V =9.0 m/s, high load and 1 Mbps data rate
Mean Number of Lost Packets
Conclusions
The rerouting of the RSVP branch path at a crossover router is considered in order to minimize the resource reservation delay and the packet loss resulting from handoffs.
Seamless rerouting scheme of RSVP branch path for soft handoff was proposed in order to guarantee the QoS of on-going RSVP flows during handoff.
This scheme could provide QoS guarantee for RSVP flows under IP micro-mobility network.