Mobility Management in Packet-based Communication Networks

Yun Won ChungElectronics and Telecommunications Research Institute

E-mail: ywchung@ieee.org

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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 ?