An Architecture for Personal BroadbandAn Architecture for Personal Broadband

Broadband Working GroupElisabeth Maida, MIT

May 25, 2006

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AgendaAgenda

• The Vision of Personal Broadband

• Our Approach– Define the potential business models– Identify the functional elements– Focus on the network selection problem– Follow an ontology-based approach– Develop the data model

• The Network Service Profile Ontology

• Next Steps

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The Vision of Personal BroadbandThe Vision of Personal Broadband

Historical constraints imposed by location, network providers, access devices, applications, and content limit a user’s ability to create a consistent, personalized, broadband experience.

• Personal Broadband is the vision of an environment in which these constraints no longer exist

• Several use cases provide examples of how Personal Broadband allows users to have ubiquitous access to their applications andcontent regardless of their location, network provider, or access device

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Use CasesUse Cases

Being best connected

Find me a printer

On the road with “my” music or video

library

Mobile Office

Personalizing the connection of a shared device

– Network provider from location

– Network providers from access device

– Sales rep is traveling to a meeting and needs to download a presentation now

Use Case Decoupled Elements Examples and Comments

– Resources from location and network provider

– User is visiting another office and needs to print a document

– Content and applications from device location

– PBB connectivity extends access to personal resources independent of location as well as “network-based” resources

– Content and applications from device location

– User has the same access to their resources regardless of their location

– Network provider from location and access device

– User and their family share a network, but have different connectivity depending on their needs

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AgendaAgenda

• The Vision of Personal Broadband

• Our Approach– Define the potential business models– Identify the functional elements– Focus on the network description problem– Follow an ontology-based approach– Develop the data model

• The Network Service Profile Ontology

• Next Steps

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Defining the Potential Business ModelsDefining the Potential Business Models

• The Personal Broadband architecture should support multiple business models.

• In order to test the flexibility of the architecture, we identified the following models:– The user pays a home provider on an on-going basis (e.g. cell phone roaming).– The user pays a 3rd party aggregator (e.g. iPass, Boingo, Paypal).– The user pays on the spot market.– The user does not pay for connectivity directly, but the cost is subsidized

through other channels (e.g. advertising and equipment purchases).

• The most relevant difference between the models is the nature of the relationship that allows the user to have connectivity.

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Identifying the Functional ElementsIdentifying the Functional Elements

Network Discovery

Access Network Selection

Authentication and Authorization

(optional)

Accounting(optional)

Revenue Generation(optional)

Risk Management

Identify which networks are available

– Does the user need to provide their information in order to receive a list of networks? If so, what information does the user need to reveal?

– Does the user only see a subset of the available networks?

– What information is the decision based on?– What information is available to higher

layers?

– Who performs the authentication and authorization?

– Are authentication and authorization always required?

– TBD

– TBD

– TBD

Select the appropriate network

Gain access to the network

Track usage of the network

Pay for the usage

Manage the risk

Function Description Associated Questions

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““Pieces of the Puzzle”Pieces of the Puzzle”Function Existing Systems and Protocols

Network Discovery

– CARD (depending on implementation)– Personal router– Rustling– 3G roaming

– International Roaming Access Protocols (IRAP)/ Extensible Authentication Protocol (EAP)

– Candidate Access Router Discovery (IETF RFC 4066)

– Service Location Protocol (IETF)– Beacon Management– Universal Description, Discovery, and Integration

(UDDI)

Access Network Selection

Authentication and Authorization

Accounting

Revenue Generation

Risk Management

– IRAP/RADIUS and Diameter

– TBD

– TBD

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Focusing on Network DescriptionFocusing on Network Description

The initial architecture work will focus on the network description or “service profile.” This description is critical to both network discovery and network selection.

There were multiple reasons for this decision:– Impacts elements which are required for all business models– Other aspects of discovery and selection have been examined and, in some

cases, defined– Description problem has not been solved, but can build on previous work

(Personal Router, Candidate Access Router Discovery, rustling)

Selection Logic

Discovery Protocol

Network Discovery

Network Selection

Network Description

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Following an OntologyFollowing an Ontology--based Approachbased Approach

• We are defining an extensible architecture for network description– Most parameters will not be used in practice– Difficult to identify critical parameters a

priori

• The ontology will provide “a formal, explicit specification of a shared conceptualization” [Gruber 1993]– Focused on network user’s agent– Party responsible for selecting the network

will vary with the business model, but all parties will need access to the same subset of information

• Objective is to create a data model describing a network service profile

Potential Elements• Bits per second• Usage fee• Cost• Jitter• Performance

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Developing the Data ModelDeveloping the Data Model

• What parameters should be included in a network’s “service profile”?

• Began by examining related work…– The Personal Router (MIT)

• Technical characteristics (bandwidth, average throughput, burst rate, burst ratio)

• Cost (price per kilobyte, price per time period)

– Candidate Access Router Discovery (IETF)• Definition of capabilities was out of scope for final RFC• Earlier versions had illustrative examples

– Rustling (BT)• Tariffs

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AgendaAgenda

• The Vision of Personal Broadband

• Our Approach– Define the potential business models– Identify the functional elements– Focus on the network selection problem– Follow an ontology-based approach– Develop the data model

• The Network Service Profile Ontology

• Next Steps

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The Network Service Profile OntologyThe Network Service Profile Ontology

• Identified 8 top-level entities– Brand– Legal Terms and Conditions– Trust and Security– Price– Physical Interface– Network Capabilities– Technical Performance– TBD

• Defined a flat hierarchy as the relationships between entities will vary with the implementation

• Checked against two test cases to ensure the ontology could be used to represent the relevant information– CARD and User Agent Profile (UAProf)

• Revisited the business models to understand how the reasoning process would vary with each model

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Related Ontology EffortsRelated Ontology Efforts

• QoS Working Group• Distributed Management Task Force• Internet Measurement Research Group• W3C Composite Capability/Preference Profiles • W3C Mobile Web Device Description Working Group • Open Mobile Alliance• Creative Commons• Platform for Privacy Preferences (P3P)• Swisscom presentation at CRN, December 2005• User-centric networking at TISPAN

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BrandBrand

• Brand in the marketing sense: the elements that impact a user’s intangible perception of a network provider

• The agent cannot make any assumptions about the characteristics of the underlying offer based on “Brand.”

• Examples:– Network operator name– Organizational affiliation or ownership– 3rd party verification or approval– Reputation

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Legal Terms and ConditionsLegal Terms and Conditions

• The business conditions of the offer

• While a network might technically support certain functionality,the terms and conditions of the service will govern its use.

• Examples:– No resale– No running servers– No tunneling

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Trust and SecurityTrust and Security

• The security, privacy, and authentication policies

• Examples:– Policy information– Device authentication and authorization– Content checking– Use of personal information

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PricePrice

• The fee(s) the user will need to pay in exchange for access to and/or use of the network– Not limited to monetary fees

• Through the combination of “Price” and “Technical Performance,” the network can associate different levels of performance and reliability with different prices

• Examples:– Initial price (upfront fee)– Usage price

• Price per kilobytes• Price per time unit

– Flat rate pricing– Tiered pricing levels– Payment form

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Physical InterfacePhysical Interface

• The channel over which the connectivity is available– For example, a user might receive an offer for access over a channel

that the user has turned off in order to save power.

• Examples:– Protocol– Band

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Network CapabilitiesNetwork Capabilities

• The network can choose to enumerate either the services it does support or the services it does not support. The user’s agent will enumerate which services it would like a network to support.

• “that which is not forbidden is permitted” vs. “that which is not permitted is forbidden”

• Examples:– Supported protocols (e.g., TCP, FTP, etc.)– Content filtering– Web proxy use– Unilateral redirection of application flows (e.g., SMTP connections)– Private vs. routed IP addresses– Handoff type (seamless, “break-before-make”)– Firewall traversal– NAT traversal– Indirection

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Technical PerformanceTechnical Performance

• Traffic primitives describing the technical characteristics of the network

• Examples:– Bit rate– Jitter– Latency– Existing load– Available bandwidth

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Test Case: Candidate Access Router Discovery Test Case: Candidate Access Router Discovery (IETF RFC 4066)(IETF RFC 4066)

Sample Category Sample Capabilities Ontology Entity

Administrative parameters

ISP name, organizational ownership, device authentication and authorization data, policy information

BrandTrust and Security

Cost of access Dollar cost per QoS class Price

Available radio interfaces

802.11, WCDMA, GSM Physical Interface

Availability of application logic

Multicast support, playout buffer hosting, TCP performance enhancing proxies, transcoding, header compression

Network Capabilities

Internet connectivity

NAT traversal Network Capabilities

Resource parameters

Existing load, available bandwidth Technical Performance

• Enable seamless IP-layer handover between access routers– Mobile nodes must discover the capabilities of candidate access routers prior to

the initiation of the handover

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Test Case: User Agent Profile Test Case: User Agent Profile (Open Mobile Alliance)(Open Mobile Alliance)

Sample Component Sample Capabilities Ontology Entity

Hardware Platform Screen size, color capabilities, image capabilities, manufacturer

NA*

Software PlatformOperating system software, supported video and audio encoders, user’s language preference

NA*

BrowserUABrowser manufacturer and version, markup languages supported, scripting languages supported

NA*

WAP Characteristics WML script libraries, WAP version Network Capabilities

Network Characteristics Latency, reliability Technical Performance

Push Characteristics Supported MIME types, device buffer size NA*

• Enables the end-to-end flow of a User Agent Profile between the WAP client, intermediate network points, and the origin server

• The origin server uses the profile information to optimize the content for the device

* These capabilities would only need to be represented in the ontology if the network would impact the content (e.g., content filtering, supported protocols). These exceptions would be included under “Network Capabilities.”

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Business Models and Agent’s ReasoningBusiness Models and Agent’s Reasoning

The decision criteria and reasoning will vary with the business model:

• Home provider– User trusts home provider

to select network– Agent’s reasoning

provided in advance by home provider (similar to cell phone roaming)

• 3rd party aggregator– Same as home provider

but the relationship is independent of a specific provider

• Spot market– User determines entire

preference structure

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AgendaAgenda

• The Vision of Personal Broadband

• Our Approach– Define the potential business models– Identify the functional elements– Focus on the network selection problem– Follow an ontology-based approach– Develop the data model

• The Network Service Profile Ontology

• Next Steps

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Next StepsNext Steps

• Development of a white paper documenting the proposed ontology

• Test implementation as part of Living the Future

• Next steps within organizations

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Related ResourcesRelated Resources

• Candidate Access Router Discovery (IETF)– http://www.faqs.org/rfcs/rfc4066.html

• Personal Router (MIT)– http://pr.lcs.mit.edu

• Rustling (BT)– G. Corliano and K. Khan, “Economic Tussles in the Public Mobile

Access Market,” BT Technology Journal, Volume 21, Issue 3, 2003, 122-133.

• User Agent Profile (Open Mobile Alliance)– http://www.openmobilealliance.org/tech/affiliates/wap/wap-248-uaprof-20011020-

a.pdf