Global Roaming in Next-Generation Networks

Theodore B. Zahariadis, Konstantinos G. Vaxevanakis, Christos P. Tsantilas, and Nikolaos A. Zervos

Ellemedia Technologies, GreeceNikos A. Nikolaou, Lucent Technologies, The Netherlands

IEEE Communications Magazine • February 2002

Date: 2006/03/29Speaker: Kai-Jie Chang

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Outlines

• Introduction

• Proposed architecture– Horizontal handover– Vertical handover architecture

• Conclusions

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Introduction

• Maximize profit and return of investment based on existing equipment.

• Organize in a cell hierarchy, based on technology either already deployed or still under development.

• Include three network, satellite network, 2G/3G cellular network and Wireless Network.

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Handover in WLAN

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WLAN roaming

• (1). Request FA• (2). Register HA via FA• (3). Response • (4). IP packets to MN through HA• (5). Redirect to FA• (6). Forward packets to MN• (7). Establish a link to MN directly.

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Handover in 2G network.

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2G horizontal roaming

• (1). Update message• (2). Forward to HLR• (3). Registration ack• (4). New connection established• (5). Initial request to HLR• (6). Route request message• (7). Return TLDN to HLR• (8). Forward TLDN to VLR• (9). Using SS7 to establish a connection between

MSCs

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Handover in LEO satellite network.

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LEO satellite roaming

• Key point – LEO is a common issue.– Signaling overhead and delay are quite signi

ficant factors that must minimized.– Satellite rotation more than terminal move

ment.– Intraplane v.s. Interplane ISL(intersatellite li

nks)– Minimize the time to identify the best ISL fo

r each connection

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Cell hierarchy of a next-generation network.

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Architecture

• Deployment of a global all-IP wireless/mobile network.

• The architecture is based on enhancements of existing equipment.– Evolutionary rather than revolutionary.

• IP is the most widely accepted protocol; thus, mobility based on IP will be leveraged.

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Equipments

• Service Support Node (SSN): – MSC+, IP L1/L2 switch, FES.

• Maintains user profile:– HLR+, HSS

• VLR, FA.• User authentication and authorization:

– RADIUS, AAA.• Interworking function (IWF), generally gateway

support nodes (GSNs).• IP allocation :

– DHCP, DNS.

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Figure 5. An all-IP wireless/mobile network.

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Conclusions

• Global roaming in current and next-generation networks is an important issue.

• This article consider a hierarchical cell architecture either installed or under development.

• Route packet rather than IP change.