Transcript Wang-WPC12-slidex

Authors: Ing-Ray Chen
Weiping He
Baoshan Gu
Presenters: Yao Zheng
»
»
»
»
»
»
Introduction
Related Work
DMAP
Model
Numerical Results
Applicability and Conclusion
» MIPv6 - Mobile IPv6
˃ A version of mobile IP, it allows an IPv6 node to be mobile
and still maintain existing connections;
» HMIPv6 - Hierarchical Mobile IPv6
˃ Proposed enhancement of MIPv6, it is designed to
reduce the amount of signaling required and to improve
handoff speed for mobile connections;
» MAP – Mobility Anchor Point
˃ Serving as a local entity to aid in mobile handoffs, it can
be located anywhere within a hierarchy of routers;
» HA - home agent
˃ A router on a mobile node’s home network that
maintains information about the device’s current location,
as identified in its CoA;
» CoA - care of address
˃ A temporary IP address for a mobile node that enables
message delivery when the device is connecting from
somewhere other than its home network;
» Location handoff
˃ Mobile node moves across a subnet boundary;
» Service handoff
˃ Mobile node moves across a DMAP domain boundary;
» The essence of DMAPwSR is the notion of
integrated mobility and service management,
which is achieved by determining an optimal
service area size;
» The objective is to minimize the total network
signaling and communication overhead in
servicing the mobile node’s mobility and service
management operations;
» Intra-regional move
˃ When the MN subsequently crosses a subnet but is still located within
the service area, it would inform the MAP of the CoA address change
without informing the HA and CNs to reduce the network signaling
cost;
» Inter-regional move
˃ The mobile node makes the AR of the subnet as the DMAP when it
crosses a service area, and it also determines the size of the new
service area;
˃ MN acquires a RCoA as well as a CoA from the current subnet and
registers the address pair to the current DMAP in a binding request
message;
» Inter-regional move
˃ The MN also informs the HA and CNs of the new RCoA address change
in another binding message so that the HA and CNs would know the
MN by its new RCoA address;
˃ DMAP intercepts the packet destined for RCoA, inspects the address
pair stored in the internal table, finds out MN’s CoA and forwards the
packet to the MN through tunneling;
» A MN’s service area can be modeled as
consisting of K IP subnets;
» The MN appoints a new DMAP only when it
crosses a service area whose size is determined
based on the mobility and service
characteristics of the MN in the new service
area;
» The service area size of the DMAP is not
necessarily uniform;
» A large service area size means that the DMAP
will not change often, while a small service area
size means that the DMAP will be changed
often so it will stay close to the MN;
» There is a trade-off between two cost factors
and an optimal service area exists;
» The service and mobility characteristics of a MN
are summarized by two parameters:
˃ The resident time that the MN stays in a subnet, represented by using
the MN’s mobility rate σ;
˃ The service traffic between the MN and server applications,
represented by using the data packet rate λ;
» The ratio of λ/ σ is called the service to mobility
ratio (SMR) of the MN;
» A computational procedure to determine the
optimal service area size
˃ The intent to find the optimal service area based on the MN’s mobility
and service behaviors
» The computational procedure requires
˃ Every AR must be capable of acting as a MAP
˃ Each MN must be powerful enough to collect data dynamically and
perform simple statistical analysis
» Aim to minimize the communication cost
˃ The signaling overhead for mobility management for informing the
DMAP of the CoA changes
˃ Informing the HA and CNs of the RCoA changes
˃ The communication overhead for service management for delivering
data packets between the MN and CNs
Symbol
Meaning
λ
Data packet rate between the MN and CNs
σ
SMR
Mobility rate at which the MN moves across
subnet boundaries
Service to mobility ratio (λ/σ)
N
Number of server engaged by the MN
Symbol
Meaning
K
Number of subnets in one service area
τ
α
1-hop communication delay per packet in
wired networks
Average distance between HA and DMAP
β
Average distance between CN and DMAP
γ
Cost ratio between wireless vs. wired
network
K
(Guard:Mark(Xs)<K-1)
Intra
Pi=1
A
K
Moves
MN2DMAP
Move
Xs
Pj=1
NewDMAP
B
(Guard:Mark(Xs)=K)
(Guard:Mark(Xs)=K-1)
A token represents a subnet crossing event by the MN
K
A temporary place
holds tokens from
transition A
Mark(Xs) holds
the number of
subnets
crossed in a
service area
Mark(Moves)=1
means that the (Guard:Mark(Xs)<K-1)
MN just moves
aross a subnet
Intra
Pi=1
A
K
Moves
MN2DMAP
Move
Pj=1
Xs
NewDMAP
B
(Guard:Mark(Xs)=K-1)
(Guard:Mark(Xs)=K)
A guard for transition A that is enabled if a move will not cross a service area
A timed
K
A timed transition for the
transition for the
A timed
MN to inform the DMAP of
MN to inform
transition for the
the CoA change
the HA and CNs
MN to move
(Guard:Mark(Xs)<K-1)
of the RCoA
across subnet
change
areas
Intra
Pi=1
A
K
Moves
Xs
MN2DMAP
Move
Pj=1
NewDMAP
B
(Guard:Mark(Xs)=K)
(Guard:Mark(Xs)=K-1)
A guard for transition B that is enabled if a move will cross a service area
» Pi: The steady-state probability that the system is
found to contain i tokens in place Xs such that
Mark(Xs)=i
» Ci,service: The communication overhead for the
network to service a data packet when MN is in the ith subnet in the service area
C
service
K
K
i 0
i 0
  ( Pi  Ci ,service )       ( Pi  i )
A delay in the
wireless link
form the AR to
the MN
A delay between
the DMAP and a
CN in the fixed
network
A delay from DMAP to the
AR of the MN’s current
subnet in the fixed network
» Ci,location: The network signaling overhead to service a
location handoff operation given the MN is in the i-th
subnet in the service area
˃ If i < K
+ Only a minimum signaling cost will incurred for the MN to inform the
DMAP of the CoA address change
˃ If i = K
+ The location handoff also triggers a service handoff
+ A service handoff will incur higher communication signaling cost to inform
the HA and N CNs of the RCoA address change
K
C
location
  ( Pi  Ci ,location )
i 0
K 1
 PK (    N )  {Pi (  i )}
i 0
A location handoff and
a service handoff
A minimum signaling cost
for the MN to inform the
DMAP of the CoA address
change
» Summarizing above, the total communication
cost per time unit for the Mobile IP network
operating under DMAPwSR scheme to service
operations associated with mobility and service
management of the MN is calculated as:
C
DMAPwSR
 C service    C location  
Service
management
cost
Mobility
management
cost
A service area under hexagonal network
coverage model
A service area under mesh network
coverage model
Access point locations at Dartmouth
College campus
» MIPv6
MIPv6
Cservice
   
A delay in the
wireless link
from the AR
to the MN
A communication
delay from the
CN to the AR of
the current
subnet
MIPv6
Clocation
     N
A delay in the
wireless link from
the MN to the AR of
the subnet that it
just enters into
A delay
from
that AR
to the
HA
MIPv6
MIPv6
CMIPv6  Cservice
   Clocation

A delay
from that
AR to the
CNs
» HMIPv6
˃ The placement of MAPs is predetermined
˃ Each MAP covers a fixed number of subnets
+ KH = 4
» A MN crosses a subnet within a MAP
˃ It only informs the MAP of its CoA
» A MN crosses a MAP
˃ Changes the MAP
˃ Obtain a new RCoA
˃ Informs the HA and CNs of the new RCoA
Cost difference between basic MIPv6, HMIPv6, and DMAPwSR
Cost ratio between DMAPwSR and MIPv6/HMIPv6
Effect of α and β on cost difference between HMIPv6 and DMAPwSR
Simulation versus analytical results: cost difference between
HMIPv6 and DMAPwSR
Cost difference under movement-based versus distancebased service area simulation
Cost difference under different residence time distribution
Cost difference under different residence time distribution
Optimal K versus SMR under various time distributions
Cost difference under different network coverage model
» A novel DMAP scheme for integrated mobility and
service management
» To apply the analysis results in the paper, one can
execute the computational procedure at static time to
determine optimal Kopt over a possible range of
parameter value