DMAP: integrated mobilityand service managementin mobile IPv6 systems
Authors: Ing-Ray Chen
Weiping He
Baoshan Gu
Presenters: Chia-Shen Lee
Xiaochen Ding
Outline
Introduction
Related Work
DMAP
Model
Numerical Results
Applicability and Conclusion
Introduction
MIPv6 - Mobile IPv6
A version of mobile IP, it allows an IPv6 node to be mobileand still maintain existing connections;
HMIPv6 - Hierarchical Mobile IPv6
Proposed enhancement of MIPv6, it is designed to reducethe amount of signaling required and to improve handoffspeed for mobile connections;
MAP – Mobility Anchor Point
Serving as a local entity to aid in mobile handoffs, it can belocated anywhere within a hierarchy of routers;
Introduction
HA - home agent
A router on a mobile node’s home network that maintainsinformation about the device’s current location, asidentified in its CoA;
CoA - care of address
A temporary IP address for a mobile node that enablesmessage delivery when the device is connecting fromsomewhere other than its home network;
Location handoff
Mobile node moves across a subnet boundary;
Service handoff
Mobile node moves across a DMAP domain boundary;
Related Work
MIP-RR
MIP Regional Registration, uses a GatewayForeign Agent to provide a regional CoA, whichacts as a proxy for regional movementmanagement;
The design is for mobility management onlywithout considering service management-inducednetwork cost.
Related Work
Hierarchical MIPv6
In HMIPv6, a regional CoA (RCoA) is allocated toa mobile node, in addition to a CoA, whenever themobile node enters a new MAP domain;
MAPs in HMIPv6 are statically configured andshared by all mobile nodes in the system;
There is no mechanism provided to determine thesize of a MAP domain in HMIPv6 for all mobilenodes that would minimize the network cost.
Related Work
IDMP
It introduces the concept of domain mobility with adomain and a domain agent to keep track of CoAof a mobile node as the mobile node roams withina domain;
It can be combined with fast handoff mechanismsutilizing multicasting to reduce handoff latencyand paging mechanisms to reduce the networksignaling cost for intra-domain movements.
DMAP
The essence of DMAP is the notion ofintegrated mobility and service management,which is achieved by determining an optimalservice area size;
The objective is to minimize the total networksignaling and communication overhead inservicing the mobile node’s mobility andservice management operations;
DMAP
Inter-regional move
The mobile node makes the AR of the subnet asthe DMAP when it crosses a service area, and italso determines the size of the new service area;
MN acquires a RCoA as well as a CoA from thecurrent subnet and registers the address pair tothe current DMAP in a binding request message;
DMAP
Inter-regional move
The MN also informs the HA and CNs of the newRCoA address change in another bindingmessage so that the HA and CNs would know theMN by its new RCoA address;
DMAP intercepts the packet destined for RCoA,inspects the address pair stored in the internaltable, finds out MN’s CoA and forwards the packetto the MN through tunneling;
DMAP
Intra-regional move
When the MN subsequently crosses a subnet butis still located within the service area, it wouldinform the MAP of the CoA address changewithout informing the HA and CNs to reduce thenetwork signaling cost;
DMAP
DMAP
A MN’s service area can be modeled asconsisting of K IP subnets;
The MN appoints a new DMAP only when itcrosses a service area whose size isdetermined based on the mobility and servicecharacteristics of the MN in the new servicearea;
The service area size of the DMAP is notnecessarily uniform;
DMAP
A large service area size means that theDMAP will not change often, while a smallservice area size means that the DMAP willbe changed often so it will stay close to theMN;
There is a trade-off between two cost factorsand an optimal service area exists;
DMAP
The service and mobility characteristics of aMN 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 serverapplications, represented by using the datapacket rate λ;
The ratio of λ/ σ is called the service tomobility ratio (SMR) of the MN;
Model
We devise a computational procedure todetermine the optimal service area size
The intent to find the optimal service area basedon 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 datadynamically and perform simple statisticalanalysis
Model
We aim to minimize the communication cost
The signaling overhead for mobility managementfor informing the DMAP of the CoA changes
Informing the HA and CNs of the RCoA changes
The communication overhead for servicemanagement for delivering data packets betweenthe MN and CNs
Our SPN model is shown later
Model
Symbol
Meaning
λ
Data packet rate between the MN and CNs
σ
Mobility rate at which the MN moves acrosssubnet boundaries
SMR
Service to mobility ratio (λ/σ)
N
Number of server engaged by the MN
F(K)
A general function relating the number ofsubnets K to the number of hops
Model
Symbol
Meaning
K
Number of subnets in one service area
τ
1-hop communication delay per packet inwired networks
α
Average distance between HA and MAP
β
Average distance between CN and MAP
γ
Cost ratio between wireless vs. wirednetwork
Stochastic Petri Net
Moves
tmp
Xs
Move
NewDMAP
MN2DMAP
K
K
A
B
Pi=1
Pj=1
(Guard:Mark(Xs)=K-1)
(Guard:Mark(Xs)<K-1)
(Guard:Mark(Xs)=K)
A token represents a subnet crossing event by the MN
Stochastic Petri Net-Places
Moves
tmp
Xs
Move
NewDMAP
MN2DMAP
K
K
A
B
Pi=1
Pj=1
(Guard:Mark(Xs)=K-1)
(Guard:Mark(Xs)<K-1)
(Guard:Mark(Xs)=K)
Mark(Moves)=1means that theMN just movesaross a subnet
A temporary placeholds tokens fromtransition A
Mark(Xs) holdsthe number ofsubnetscrossed in aservice area
Stochastic Petri Net-Transitions
Moves
tmp
Xs
Move
NewDMAP
MN2DMAP
K
K
A
B
Pi=1
Pj=1
(Guard:Mark(Xs)=K-1)
(Guard:Mark(Xs)<K-1)
(Guard:Mark(Xs)=K)
A timedtransition for theMN to moveacross subnetareas
A timed transition for theMN to inform the DMAP ofthe CoA change
A timedtransition for theMN to informthe HA and CNsof the RCoAchange
A guard for transition B that is enabled if a move will cross a service area
A guard for transition A that is enabled if a move will not cross a service area
Transition Rate
MN2DMAP
![MCj04136020000[1]](data/images/img5.png)
![MCj04316320000[1]](data/images/img6.png){kind=small}
![MCj04136020000[1]](data/images/img7.png)
Wireless one-hopcommunicationdelay per packet
The number of hopsbetween the currentsubnet and the DMAPseperated byMark(Xs)+1 subnets
Transition Rate
NewDMAP
The communication cost includes that for the MN toinform the HA and CNs of the new RCoA change
The averagedistance inhopsbetween theMN and theHA via wirednetwork
The averagedistance inhopsbetween theMN and NCNs via wirednetwork
Cost of Service Management
Pi: The steady-state probability that thesystem is found to contain i tokens in placeXs such that Mark(Xs)=i
Ci,service: The communication overhead for thenetwork to service a data packet when MN isin the i-th subnet in the service area
A delay betweenthe DMAP and aCN in the fixednetwork
A delay from DMAP to theAR of the MN’s currentsubnet in the fixed network
A delay in thewireless linkform the AR tothe MN
Cost of Location Management
Ci,location: The network signaling overhead toservice a location handoff operation given theMN is in the i-th subnet in the service area
If i < K
Only a minimum signaling cost will incurred for the MNto 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 communicationsignaling cost to inform the HA and N CNs of theRCoA address change
Cost of Location Management
A location handoff and
a service handoff
A minimum signaling costfor the MN to inform theDMAP of the CoA addresschange
Cost of DMAP
Summarizing above, the total communicationcost per time unit for the Mobile IP networkoperating under our DMAP scheme to serviceoperations associated with mobility andservice management of the MN is calculatedas:
Servicemanagementcost
Mobilitymanagementcost
Numerical Results
We calculate CDMAP as a function of K anddetermine the optimal K
K represents the optimal “service area” size
The size will minimize the network cost given
A set of parameter values charactering the MN’smobility and service behaviors
We present results to show that
There exists an optimal service area under DMAP
Demonstrate the benefit of DMAP over basicMIPv6 and HMIPv6
Numerical Results
MIPv6
A delay in thewireless linkfrom the ARto the MN
A communicationdelay from theCN to the AR ofthe currentsubnet
A delay in thewireless link fromthe MN to the AR ofthe subnet that itjust enters into
A delayfromthat ARto theHA
A delayfrom thatAR to theCNs
Numerical Results
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
Numerical Results
Comparing DMAP with basic MIPv6 and HMIPv6 head-to-head from theperspective of Kopt
Numerical Results
Cost difference between basic MIPv6, HMIPv6, and DMAP
Numerical Results
Effect of α and β on CHMIPv6 − CDMAP
Numerical Results
Effect of F(k) on CHMIPv6 − CDMAP
Applicability and Conclusion
We proposed a novel DMAP scheme for integratedmobility and service management
To apply the analysis results in the paper, one canexecute the computational procedure at static timeto determine optimal Kopt over a possible range ofparameter values
In the future, we plan to consider the implementationissue by building a testbed system to validate theanalytical results as well as testing the sensitivity ofthe results with respect to other time distributionsother than the exponential distribution used in theanalysis
Q & A