Application Layer Mobility Management Schemefor Wireless Internet

Mohamed Elkanzi

Contents

• Introduction• 3G IP Architecture• Mobility Management• Wireless IP Hand-off• Registration• Configuration & Dynamic Address Binding• Proposed Tier• Experiments• Conclusions

Introduction

• As the number of wireless devices connecting to the internet is increasing, more work needs to be done to standardize the all the IP wireless networks.

• IETF, 3GPP and MWIF• The focus is to merge the wireless and the

wireline networks.• MIP provides some solutions but creates

some problems too.• SIP as an alternative for MIP

3G IP Architecture

Domain Control Agent

Domain Control Agent

Regional IP NetInternet Regional IP Net

Radio Access Network (RAN)

Radio Access Network (RAN)

Mobility Management

• Mobility management requirements:– Availability– Global roaming– Supports real time (telephony) and non-

real-time (mobile web access) services.– Supports TCP applications– Supports multicast connections– Handles registration, configuration,

dynamic binding, and location management

Wireless IP Hand-off

• The procedure is divided into three logical layers:– Cell hand-off– Subnet hand-off– Domain hand-off

Registration

• Newly joining MS sends registration• The network performs:

– Accounting– Authorization– Auditing

• When a MS moves between subnets appropriate registration is carried out by intermediate servers or SIP agents.

Configuration & Dynamic Address Binding• As MS changes networks it requests a

new IP and the network’s subnet information

• The DNS should be updated automatically• Dynamic Address Binding is for an MS to

maintain an address during its session no matter which network it belongs to.

• Location management is maintained and updated frequently

Proposed Tier: Terminal Mobility• Multimedia traffic is categorized as

realtime and non-realtime by loss and delay factors.

• Different protocols are used to transport the categorized traffic.

• RTP/UDP is for realtime traffic• TCP is for non-realtime traffic

Terminal Mobility for Real-Time application• For real-time applications delay and

loss are the major concern• Triangular routing and packet

encapsulation should be avoided• Hand-off must be efficient• SIP is used to support subnet and

domain handoff, while cell hand-off is taken care by the link layer

Non-real-time Applications

• SIP signaling is used to transport TCP packets.

• Each MS has a SIP agent that maintains its TCP connections

• The agent also maintains the MS’s original and current IP addresses.

Service & Personal Mobility

• This aspect assures that the user is able to maintain and obtain services.

• The server’s ability to control the user’s sessions and services. These properties could be transferred during hand-off and SIP registration

• SIP’s URI provides the user with the ability to make use of the services anywhere anytime.

Test-bed

Experiments

• Customized version of University Columbia’s SIP client sipc and SIP server sipd

• Two clients over IEEE 802.11 environment

• A lighter DHCP version was used DRCP

Conclusions

• The proposed architecture provides an alternative for a wireless internet enabled services

• SIP provides a flexible protocol to maintain and obtain services while being mobile.