Mobile Push: Delivering Content to Mobile Users

1
Mobile Push Delivering Content to Mobile Users

• Ivana Podnar
• Dept. of Telecommunications
• University of Zagreb, Croatia
• ivana.podnar_at_fer.hr

Manfred Hauswirth Distributed Information
Systems Lab, EPFL, Switzerland Manfred.Hauswirth_at_e
pfl.ch
Mehdi Jazayeri Distributed Systems
Group Technical University of Vienna,
Austria M.Jazayeri_at_infosys.tuwien.ac.at
2
Overview

• Mobile push service
• definition
• motivation
• publish/subscribe interaction style
• Service usage scenarios
• Proposed architecture
• Related work
• Conclusion

3
Mobile push service

• Content dissemination service supporting mobile
  users
• delivery of content from information sources
  (publishers) to numerous destinations
  (subscribers) across a wide area network
• content, information - non-real-time data
• publishers and subscribers are mobile users
• user mobility (personal mobility) - a user is an
  end communication point

4
Motivation

• Users want to be served with timely information
  
• push-based content dissemination
• information must conform to user preferences
  (subscriptions, efficient content filtering)
• Usage scenarios involving user mobility are
  increasingly popular
• user applies various end terminals in different
  networks
• Location-based services
• content delivery based on current user location
• Applications for the Mobile Internet

5
Content dissemination service
Service infrastructure
Content sources
Content destinations
Channel1
Channel2
Publisher
Subscriber
Channeln
Publisher
Subscriber
Subscriber
6
Content dissemination service
Service infrastructure
Content sources
Content destinations
Channel1
Channel2
Publisher
Subscriber
publish
notify
Channeln
Publisher
Subscriber
notify
Subscriber
7
Content dissemination model

• Publishers (P)
• mobile entities characterized by advertisements
  (ad)
• Subscribers (S)
• mobile entities characterized by subscriptions
  (sub)
• Content dispatchers (CD)
• stationary entities that compose the service
  infrastructure
• manage subscriptions (sub) and advertisements
  (ad)
• route content along channels
• Channel (ch)
• logical connector between publishers and
  subscribers
• topic-based content classification

8
Model example

P1
P3
CD1
CD2
P2
S2
CD4
CD3
CD5
S1
S3
S4
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Model example

P1
P3
CD1
CD2
P2
S2
CD4
notification
CD3
CD5
S1
S3
S4
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Model example

P1
P3
CD1
CD2
P2
S2
CD4
S3 requests more content
CD3
CD5
S1
S3
S4
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Content dissemination vs. publish/subscribe

• publish/subscribe interaction
• subscribers subscribe to a service and receive
  content published by publishers
• the service acts as an intermediary between
  publishers and subscribes
• publishers and subscribers are decoupled
• distributed architecture

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Content dissemination vs. publish/subscribe
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Problem statement

• Investigate the requirements and design an
  architecture for a content dissemination system
  supporting personal mobility in heterogeneous
  networks
• How can I use publish/subscribe middleware to
  design, implement, and deploy a content
  dissemination service that supports personal
  mobility?
• What other services (components) do I need for
  such a system?
• Is there an existing publish/subscribe system
  adequate for mobile environments?

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System requirements

• Disseminate potentially large content items
  (non-realtime data) across a wide area network
• minimize bandwidth consumption
• A user may employ different end devices in
  heterogeneous networks
• Enable personal mobility
• a user is an end communication point
• Deliver personalized content
• a user may specify rules for content delivery
  regarding the currently used end device, or
  content

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Stationary publishers/subscribers
Gateway
Internet
S
P
Gateway
content dispatcher
CD
P
S
publisher
CD
S
subscriber
permanent IP address
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Stationary publishers/subscribers

• Services
• subscription management creates, updates, and
  stores subscriptions and advertisements
• content queuing strategy stores the published
  content matching subscribers subscription when a
  subscriber is offline and delivers it upon
  reconnection
• content management enables a publisher to
  define content for channels
• user profile management defines subscriber
  preferences
• content-based filtering enables personalized
  content delivery according to subscribers
  preferences

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Nomadic publishers/subscribers
Base station
S
Foreign Network
dynamic IP address
Internet
Gateway
S
P
S
ISP
Gateway
Home Network
S
CD
dynamic IP address
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Nomadic publishers/subscribers

• Services
• subscription management
• content queuing strategy
• content management
• user profile management
• content-based filtering
• location management store the current address
  of the subscribers host because a CD may need to
  initiate a connection to the host
• Mobile IP a subscriber uses the same host in
  different networks
• DHCP and dynamic DNS a subscriber is within one
  network but the host address changes

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Mobile publishers/subscribers
GPRS/UMTS
Internet
Gateway
SSN
IP backbone
BSC/RNC
Gateway
Base station
Base station
S
S
CD
P
PDA
mobile phone
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Mobile publishers/subscribers

• Services
• subscription management
• content queuing strategy
• content management
• user profile
• content-based filtering
• location management enable personal mobility (a
  user may employ different end devices in
  heterogeneous networks)
• content adaptation and presentation adapt the
  content to the applied network and end device

21
Proposed architecture (high-level view)
content management and presentation
application layer handoff
application layer
user profile management
adaptation management
location management
P/S management
service layer
publish/subscribe middleware
communication layer
TCP
UDP
transport layer
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Sequence diagram for publish and subscribe use
cases
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Proposed architecture - basic components
content management and presentation
application layer handoff
application layer
user profile management
adaptation management
location management
P/S management
service layer
publish/subscribe middleware
communication layer
TCP
UDP
transport layer
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P/S management and P/S interaction
P
S
P/S management
P/S management
Sub
Sub
(un)subscribe publish
(un)subscribe publish
P/S
P/S
P/S topology
network topology
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P/S management and P/S interaction
P
S
P/S management
P/S management
Sub
Sub
publish(c11, ch1)
P/S
P/S
P/S topology
network topology
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P/S management and P/S interaction
P
S
S disconnects
P/S management
P/S management
Sub
Sub
P/S
P/S
P/S topology
network topology
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P/S management and P/S interaction
P
P/S management
P/S management
Sub
Sub
getLocation(S)
Location
P/S
P/S
P/S topology
network topology
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P/S management and P/S interaction
P
P/S management
P/S management
Sub
Sub
subscribe(S reconnects)
Location
P/S
P/S
P/S topology
network topology
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P/S management and P/S interaction
P
S reconnects
S
P/S management
P/S management
Sub
Sub
Location
P/S
P/S
P/S topology
network topology
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P/S management and P/S interaction
P
S
P/S management
P/S management
Sub
Sub
P/S
P/S
P/S topology
network topology
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Related work

• Minstrel - DSG, Technical University of Vienna
• push system for flexible, scalable and secure
  content delivery in the area of e-commerce
• two-phase dissemination approach (advertising
  delivery)
• current implementation supports stationary users
• ELVIN - DSTC, The University of Queensland
• notification service with limited mobility
  support
• proxy server to queue messages for unreachable
  mobile devices

32
Related work

• Cambridge Event Architecture (CEA) - Opera group,
  University of Cambridge
• publish/subscribe middleware system
• a mediator receives notifications on behalf of a
  subscriber during disconnections
• the mediator can register interest in
  subscribers location
• Java Event-based Distributed Infrastructure
  (JEDI) - CEFRIEL, Politecnico di Milano
• moveIn/moveOut methods to connect/disconnect from
  a dispatching server
• routing - algorithm with a dynamic dispatching
  tree

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Related work

• iBUS//Mobile Softwired
• JMS compliant product that enables mobile devices
  to connect to server-side Java applications
• Application Server iBus//Mobile Gateway
• support for native and Java-enabled devices
  (light-weight JMS client library)
• Multimedia Messaging Service (MMS) - 3GPP
• non-realtime multimedia messaging in 2.5G/3G
  networks

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Conclusion

• Representative scenarios for mobile push service
  (stationary, nomadic, and mobile users)
• Proposed architecture for content dissemination
  supporting personal mobility
• Open issues
• location management for personal mobility
• efficient routing algorithms
• race conditions and message persistence
• flexible system integration