Transcript ABC Networks

Always Best Connected
Networks
An overview
Dênio Mariz
Igor Chaves
Thiago Souto
{denio,igor,mouse}@gprt.ufpe.br
Aug, 2004
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Agenda
 Motivation
 ABC concept
 ABC scenario
 ABC actors
 ABC reference model
 Solution components
 Conclusions
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Global Connectivity
 Over the last few years, we have experienced a variety of
access technologies being deployed
 2G  3G cellular systems
 Worldwide coverage
 Wireless LAN (WLAN) solutions have been extensively
deployed to provide hot spots access
 Airports, hotels, conference centers
 High-bandwidth Internet access
 Fixed access tied to WLAN in office and home environments
 DSL + Bluetooth + WLAN + Cellular + ...
 Connectivity (almost) everywhere
 Environments of multiple access technologies
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The ABC concept
 Always Best Connected (ABC) refers to
 Being not only always connected
 But also being connected in the best possible way at all times
 ABC Networks concept allows a personalized connectivity to
the devices and access technologies that best suit his or
her needs
 Example: Combining worldwide coverage of GSM with high
bandwidth of WLAN hot spots
 Depending on the application and user preferences, a user
can be connected over multiple accesses in parallel
 ABC concept include all types of access technologies:
 Fixed and wireless
 Existing and future technologies
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What is Best Connected ?
 The definition of Best depends on different aspects
 Personal preferences
 Size and capabilities of the device
 Application requirements
 Security
 Operator or corporate policies
 Available network resources
 Networks coverage
 Price
 (Other ?)
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ABC Scenario
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1. Maria gets up in the morning and checks her e-mail in her
laptop using a DSL connection. She will have a meeting
soon and starts downloading a huge document.
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ABC Scenario
2
2. Maria unplug her laptop and heads for the office. The
laptop automatically checks for other available accesses
and finds 3G coverage. The download resumes.
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ABC Scenario
3
3. Maria takes the subway and join to the already started
meeting using her PDA. The conference tool adapts to the
limited capabilities of the access technology (sound only).
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ABC Scenario
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4. Maria leaves the subway and walks to her office. The
meeting continues on her PDA now with video (B&W).
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ABC Scenario
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5. Maria gets to the office and transfers the conference to her
desktop which is connected to the WLAN. The conference
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tool now enables full video.
ABC Actors
 A number of people and organizations are involved in
providing ABC service
 ABC user
 Access operator
 ABC service provider
 Application service provider
 The corporation the user works (allowing corporate access to
the user)
 One corporation can play several roles
 there may be several corporations with business
agreements among them
 A common AAA infrastructure is needed
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ABC Reference Model
 The technical aspects involved in ABC solutions are
distributed along several components
ABC
terminal
Access
devices
PAN or combined device
Access
network
ABC
service
provider
network
Application
server
Corporate
network
Correspondent
terminal
 Integrated terminal:
 The ABC terminal and Access device are one and the same
 Personal Area Network (PAN) scenario:
 Several ABC terminals using the same access device
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User Experience
 Subscription
 Seamless information delivery
 Mobility support
 User interaction and perception
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Solution Components
 Content adaptation
 Profile handling
Content adaptation
 Mobility management
 AAA support
 Access selection
Profile handling
Mobility Management
 Access discovery
AAA support
Access selection
Access discovery
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Access Discovery
 Terminal must discover available networks and access
devices
 At boot up
 Also periodically to find out if a better option is available
 Key issues
 To define a generic set of parameters describing access
networks and devices
 Operator, QoS, cost, type of access device
 How the information about access networks should be
collected (statistics, measurements, operator info, …)
 To handle the dynamics of PAN devices
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Access Selection
1/2
 Access selection is the process of deciding over which
access network to connect at any point in time
 Terminal-based selection
 Network-based selection
 User intervention
 Network-based
 Allows for load balancing
 May reduce signaling over radio interface
 Can maximize total system throughput
 Seems will be dominant (my bet )
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Access Selection
2/2
 Aspects to consider:
 User profile (preferences) must be taken in consideration
 There may be a set of preferences (at home, at work, …)
 Application requirements
 Network characteristics (available bandwidth, Cost, …)
 Device capabilities
 Key issues in Access Selection
 On line Algorithms to select the access subsystem among
several available options and restrictions
 How to provide a easy-to-understand tool for the user to show
him his current ABC options
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AAA Support
1/2
 Authentication, Authorization, and Accounting (AAA)
 Purpose
 Verify user identity (authentication)
 Verify the service to which ABC user is entitled (authorization)
 Collect data to present the bill (accounting)
 AAA is a key component in ABC scenario
 PAN
 Access network
 ABC service
 Corporate network
 Several corporations providing pieces of an entire solution
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AAA Support
Access operator
and ABC service
provider: ACME
ACME AAA
Server
2/2
3) Authentication request
3G access
network
Hotspot AAA
Server
Access operator:
hotspot
WLAN access
network
Business agreement
Business
agreement
2) Authentication
request
1) user moves into WLAN coverage
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Mobillity Management
 Mobility is one of the key issues in ABC
 may be provided as part of ABC service
 Mobility enhancements to provide: 1) Session continuity; 2) Session
transfer; 3) Reachability (or Presence)
 Session continuity
 To maintain a session when terminal moves between different
access networks
 Mobile IP can help on this
 Session transfer
 To maintain a session when terminal moves between different
devices (PAN)
 Reachability
 The ability to reach an ABC user at his current access network and
device
 Session Initiation Protocol (SIP) can help on this
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Profile Handling
 ABC service providers can offer various services to different
users
 User profile contains user personal preferences
 Choice of access
 Application adaptation
 VPN solutions
 AAA information
 The user profile is stored by ABC service provider
 Can be updated by the user
 Security is a key issue handling user profiles!
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Content Adaptation
 Approaches for content adaptation
 The application to detect changes in network characteristics
(or terminal capabilities) and request application server to
adapt contents accordingly
 The terminal to provide information about the access network
to the application and application server
 The access network to provide information to the application
server and/or terminal regarding QoS changes on network
 Key issues
 Signaling among application, terminal, access network
 Support for dynamic reconfiguration depending on a variety of
external factors: media formats, mobility, QoS matching the
access network characteristics
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Conclusions
 ABC concept offers




the user connectivity over multiple access technologies
optimized application performance
seamless mobility
session management
 It is a new paradigm for network integration
 PAN, WPAN, LAN, WLAN, 2.5G, 3G, 4G …
 New business relationships
 Introduces new challenges
 Access discover
 Access selection
 Mobility, signaling, session stability
 Content adaptation
 AAA and other security aspects
 Others
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References
 E. Gustafsson and A. Jonsson, Always Best Connected, IEEE
Wireless Communications, Vol. 10, No. 1, pp. 49-55, Feb
2003.
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