Mobility Management in Packet-based Communication Networks
Yun Won ChungElectronics and Telecommunications Research Institute
E-mail: [email protected]
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Contents
Introduction
Mobility management in circuit-based
communication networks
Mobility management in packet-based
communication networks
Mobility management in all-IP networks
Further studies
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Introduction
Mobility management Location management
Location update (registration)
Call delivery
Handoff management
Tradeoff between location update and call delivery Signaling load analysis
Resolution of location information (i.e., cell, location area,
service area)
Mobility Management in Circuit-based Communication Networks
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Location Management
Location update Call delivery
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Network Service Area in 2G Systems
* source: reference [1]
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Location Registration and Call Delivery
Centralized database architecture Dynamic hierarchical architecture
Per-user location caching
User profile replication
Pointer forwarding
Local anchoring
Distributed database architecture A fully distributed registration scheme
Partitioning
Database hierarchy
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Location Update and Terminal Paging
Location update schemes Dynamic LA management
Three dynamic update schemes Time-based
Movement-based
Distance-based
Terminal paging schemes Paging under delay constraints
Update and paging under delay constraints
Mobility Management in Packet-based Communication Networks
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Mobile Station State
In circuit-based communication networks MT is in idle or busy state
In packet-based communication networks MS is in Idle, ready, or standby state in GPRS UE is in PMM-detached, PMM-idle, cell-connected, or URA-
connected state in UMTS Cell, URA, RA, or LA is the unit area for location update Frequency of location update and paging depend on
the state of MS or UE Effect of timer (i.e. ready timer, inactivity timer, etc.) is
important
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Network Service Area in GPRS
* source: reference [1]
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GPRS MS State Model
Idle MS is not reachable After attach, the MS moves to
ready state Ready
Packet transmission is possible
Cell-based location update is performed
Ready state can be sub-divided into ready(off) and ready(on)
Standby RA-based location update is
performed
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URAs, RAs, and LAs in UMTS
* source: reference [2]
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UMTS UE State Model
MM state model in SGSN
RRC state model in UTRAN
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UMTS UE MM and RRC States
MM state PMM detached
UE is not reachable PMM connected
Packet switched (PS) signaling connection is established Serving RNC id is stored Cell-connected or URA-connected
PMM idle PS signaling connection is released Only RA information is stored
RRC state Idle
No RRC connection Cell connected
Cell level location information is managed Stays until inactivity timer expires
URA connected URA level location information is managed
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Research on the Analysis of MS State
Yun Won Chung, Dan Keun Sung, and A. Hamid Aghvami, “Steady State
Analysis of Mobile Station State Transitions for General Packet Radio
Service,” in Proc. PIMRC’2002, pp. 2029 – 2033, Lisbon, Portugal, 2002
Yun Won Chung, Dan Keun Sung, and A. Hamid Aghvami, “Steady State
Analysis of User Equipment State Transitions for Universal Mobile
Telecommunications Systems,” in Proc. PIMRC’2002, pp. 2034 – 2038,
Lisbon, Portugal, 2002
Yun Won Chung and Dan Keun Sung, “Modeling and analysis of
combined mobility management and implicit cell update scheme in
General Packet Radio Service,” in Proc. VTC’2003 Spring, Jeju, Korea,
2003
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Analysis of GPRS MS State
Location update & paging in GPRS Cell in ready state
RA in standby state
Location update and paging frequencies depend on the state
of MS
Tradeoff between location update and paging signaling based
on the number of cells in an RA
Derivation of steady state probability of MS
Performance analysis using steady state probability
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Modified MS State Model Exit from Idle
Ready(off) by Attach (T12)
Exit from Ready(off)
Idle by detach (T21)
Ready(on) by packet session arrival
(T23)
Standby by ready timer expiry (T24) Exit from Ready(on)
Idle by Detach (T31) Ready(off) by completion of session
processing (T32) Exit form Standby
Idle by Detach (T41) Ready(off) by RA update due to
movement or RA update timer expiration (T42)
Ready(on) by packet session arrival (T43)
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Steady State Probability
Stationary probability
Steady state probability
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Numerical Example
P1: idleP2: ready(off)P3: ready(on)P4: standby
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Analysis of UMTS UE State
Location update & paging in UMTS Cell in cell-connected state
URA in URA-connected state
RA in PMM-idle state
Location update and paging frequencies depend on the state
of UE
Derivation of steady state probability of UE
Performance analysis using steady state probability
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Modified UE State Model Exit from PMM detached
Cell connected (off) by attach (T12)
Exit from Cell connected (off) PMM detached by detach (T21)
Cell connected (on) by packet session arrival (T23)
URA connected by inactivity timer expiry (T24)
Exit from Cell connected (on) PMM detached by detach (T31)
Cell connected (off) by completion of session processing (T32)
Exit form URA connected PMM detached by detach (T41)
Cell connected (off) by URA update (T42)
Cell connected (on) by packet session arrival (T43)
PMM idle by URA update timer expiration (T45)
Exit from PMM idle Detach request (T51)
RA update due to movement of a UE or expiration of an RA update timer (T52)
Incoming or outgoing session arrival (T53)
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Numerical Example
P1: PMM detachedP2: cell connected(off)P3: cell connected(on)P4: URA connectedP5: PMM idle
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Combined Mobility Management
* source: reference [1]
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Combined Mobility Management
Location Update Based on LA in GSM Based on cell or RA in GPRS Size of LA > size of RA
Paging Based on paging area (= LA or RA)
Combined Mobility Management Class-A mode MS
Attached to both GSM and GPRS Supports simultaneous operation of GPRS and GSM services
Gs interface between SGSN and MSC/VLR Combined RA/LA update using one radio signaling message Circuit-switched paging via SGSN to either RA or cell based on a
GPRS MS state Efficient management of GSM/GPRS MM
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Combined Mobility Management
Implicit cell update The location of MS is known to network if GSM MS is in busy
state How can we utilize this cell-based location information for
Class-A GPRS MS state management? After the implicit cell update, paging only one cell may be
sufficient for call or packet delivery if the cell location is managed
A new MS state model Incorporation of GSM MS state into GPRS MS state Ready state can be sub-divided into ready(off), ready(on)-
GSM, ready(on)-GPRS, ready(on)-GSM/GPRS
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Modified MS State Model
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Numerical Examples
Mobility Management in All-IP Networks
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Micro-Mobility Protocols
Cellular IP
HAWAII
Regional registration
Hierarchical Mobile IP
Fast handoff
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Seamoby Activities
RFC 2132: dormant mode host alerting (“IP paging”) problem statement
RFC 3154: requirements and functional architecture for an IP host alerting protocol
MH state Active Dormant
Functional entities Paging agent Tracking agent Dormant monitoring agent
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Motivation of IP Paging
Consider an MH, which is moving fast and is not involved in a communication
Bandwidth consumption Processing power Protocol states
Optimization for nodes that are currently not in a session might be taken into consideration
Entering dormant mode Avoids frequent location update Decreases the preciseness of the network’s knowledge about
individual mobile’s location to paging areas Dormant mode supports
saving scarce radio bandwidth cutting superfluous location updating reducing battery energy drainage
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P-MIP (an Idle MN’s Movement)
HAHA
Reg request
Reg reply
FA
MN
PA1 PA2
* source: reference [3]
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P-MIP (Page an Idle MN)
HAHA
FA
MN
CN
data
paging
reg
* source: reference [3]
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Analysis of P-MIP MS State
Yun Won Chung, Dan Keun Sung, and A. Hamid Aghvami, “Steady State Analysis of P-MIP Mobility Management,” IEEE Communications Letters, June 2003
P-MIP MS State Active Idle
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Numerical Examples
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Further Studies
Multicast accommodating host mobility
Power saving MM algorithm
Vertical handoff
Mobility support in WLAN
Network mobility
Integrated MM in heterogeneous all-IP networks
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References
1. Brahim Ghribi and Luigi Logrippo, “Understanding GPRS: the GSM
packet radio service,” Computer Networks, vol. 34, pp. 763-779, 2000.
2. Yi-Bing Lin, Yieh-Ran Haung, Yuan-Kai Chen, and Imrich Chlamtac,
“Mobility management: from GPRS to UMTS,” Wireless Communications
and Mobile Computing, vol. 1, pp. 339-359, 2001.
3. Xiaowei Zhang, “Paging in Mobile IP”, presentation material on the 4th
International Workshop on Wireless Mobile Multimedia, Rome, Italy, July
2001, http://www.comet.columbia.edu/~xzhang/pmip/
4. I. F. Akyildiz, et al., Mobility management in next-generation systems,
Proceedings of the IEEE, vol. 87, no. 8, Aug. pp. 1347 – 1384, 1999.
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Any Questions & Comments ?