Application Layer Mobility Management Scheme for Wireless Internet

1
Application Layer Mobility Management Scheme for
Wireless Internet

• Henning Schulzrinne

2
Outline

• Introduction
• A 3G-IP Architecture
• Mobility Management Requirements and issues
• Mobility Tiers
• Architecture Realization
• Conclusion and Open Issues

3
Introduction

• It is envisioned that an end-to-end
  wireless/wireline IP platform comprising 3G
  wireless access networks and a wireline IP
  backbone will support real-time and non-real-time
  multimedia services in the future.
• Mobile IP does not provide means of device
  independent personal mobility and location
  service.

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Introduction (cont.)

• SIP supports personal mobility as part of its
  signaling mechanism and provide adequate means of
  terminal, and service mobility.
• SIP works with other set of IETF protocols such
  as DHCP, AAA, Diffserv to provide different
  functionality such as address assignment,
  security, accounting and QoS.

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A 3G-IP Architecture

• A 3G_IP network comprises all IP wireless access
  networks and a packet switched IP backbone
  network.
• A wireless access network consists of a radio
  access network (RAN), and an Edge Router and
  Controller.

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A 3G-IP Architecture (cont.)
7
A 3G-IP Architecture (cont.)

• Radio Access NetworkIt provides MSs with
  wireless access to the wireline infrastructure.
• Edge Router ControllerAn ERC is a routing and
  control system that connects a wireless access
  network to a regional wireline IP network. An ERC
  comprises two functional entitiesan edge router
  (ER) and an edge control agent (ECA).
• Domain Control AgentIt provides session
  management as well as the means of interaction
  between users and network control system.

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A 3G-IP Architecture (cont.)

• The Domain Control Agent also supports
• Each domain control agent would interact with
  each other directly or via an Inter-Domain
  control agent.

• Mobility Management
• Authentication, Authorization and Accounting
  (AAA)
• QoS management

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Mobility Management Requirements and Issues

• Mobility management scheme of wireless IP
  networks satisfies the following requirements

• Supports means of personal, service and terminal
  mobility.
• Supports global roaming.
• Supports both real-time and non-real-time
  multimedia services
• Transparently supports TCP based application.
• Support multicast and anycast.

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Issues

• Hand-off
• Registration
• Configuration
• Dynamic Address Binding
• Location Management

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Hand-off

• It is known as hand-over is a process that allows
  an established call to continue when an MS over
  from one cell to another without interruptions in
  the call.
• Hand-off process can be either hard or soft.
• A maximum acceptable hand-off time of 2-3 seconds
  is required.

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Hand-off (cont.)

• Three logical levels of hand-off procedure can be
  defined
• Through performing the AAA process to verify
  users identities, hand-off should ensure
  integrity, privacy and confidentiality of users
  location.

• Cell Hand-off
• Subnet hand-off
• Domain hand-off

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Hand-off (cont.)
14
Registration

• It is a process by which a network is made aware
  of the existence and location of an MS and its
  associated user.
• This process comprises sending a registration
  request from the MS to the network and performing
  an AAA process by the network.
• Depending upon the extent of registration, it ca
  be categorized as complete or expedited/partial
  registration. Former one usually takes more time
  than latter one.

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Configuration

• It is a process by which an MS updates its IP
  address as it roams between subnets either within
  the same administrative domain or in different
  administrative domains.
• Key requirement of re-configurationno more than
  a few hundred milliseconds to complete.
• The DNS should get updated automatically.

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Dynamic Address Binding

• It is a process for allowing an MS to maintain a
  constant identifier regardless of its point of
  attachment to the network after the session is
  established.
• This must be minimum packet loss and less
  overhead associated with the media.

17
Location Management

• Location management is a process by which the
  network updates the location database, and
  supports location/redirect services.
• Location service is essential for new inbound
  sessions, before a session is established.

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Mobility Tiers

• Terminal mobility
• Service mobility
• Personal mobility

• For real-time application
• For non-real-time application

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Terminal Mobility

• Multimedia traffic is categorized as real-time or
  non-real-time traffic and is mostly characterized
  by delay and loss factors.
• Most of the real-time traffic is carried over
  RTP/UDP and non-real-time traffic is carried over
  TCP.
• Terminal mobility provide means of cell, subnet
  and domain hand-off while the session is in
  progress.

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Terminal mobility for real-time application

• Multimedia application are typically RTP/UDP
  based delay and loss are of primary concern.
• It is necessary to avoid the triangular routing
  and any kind of encapsulation mechanism.
• Hand-off is an factor for terminal mobility for
  multimedia which would determine the latency.
• SIP is used to support subnet and domain hand-off
  and it uses a combination of DHCP and an AAA
  protocol.

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For non-real-time application

• The MS is equipped with a SIPeye agent that
  maintains a record of its ongoing TCP
  connections.
• SIPeye records a state comprising 3 integers.
  (original MS IP address, current MS IP address,
  original CH IP address).
• The CH and the MS use IP encapsulation.

22
Service mobility

• It allows users to maintain access to their
  services even while moving or changing devices
  and network service providers.
• Service home provider with service mobility
  should maintain control of the services and QoS
  of ongoing sessions as the user roams around.

23
Personal mobility

• It refers to the ability of end users to
  originate and receive calls and access the
  subscribed network services on any terminal in
  any location in a transparent manner.
• SIPs URI scheme and registration mechanism are
  some of the main components which would provide
  personal mobility.
• A roaming user can be accessible independent of
  the device one is logged on.

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Architecture realization

• Testbed

Columbia Universitys sipc (SIP client) and sipd
(SIP server). IEEE 802.11 environment Linux based
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Architecture realization (cont.)
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Conclusion and open issues

• This paper outlines the requirements and issues
  involved with mobility management in a
  3G-wireless Internet environment.
• It describes an application layer solution to
  variety of mobility to a roaming user by using
  SIP signaling scheme.