When the Internet meets Context Aware Computing: User Context Module Design. Yu Lu (Victor)

Yu Lu (Victor)

Advisors: Prof. Lawrence Wong and Prof. Mehul Motani

Interactive and Digital Media Institute (IDMI)

When

the

Internet

meets

Context

‐

Aware

Computing:

Outline

I. Motivation

II. Architectural Design of User‐Context Module III. Applications of User‐Context Module

IV. A Resource Distribution Framework under User‐Context Module V. Summary and Future Research Directions

I.

Motivation

Many fundamental and respected design principles have been

implemented since the Internet was born (ARPANET):

¾ Packet switching for multiplexing

¾ Global addressing for routing datagrams

¾ Layered architecture for task partition

¾ End-to-End arguments for defining communication protocols

I.

Motivation

Internet serves as the communication medium between two

networked hosts that Desire Speaking to each other*.

*D. D. Clark, “The design philosophy of the DARPA Internet Protocols,” SIGCOMM Comput. Commun. Rev., pp. 102–111,1995.

End-User

Networked Host

Internet Client that Desires Communicating

Internet Services

Internet Client

I.

Motivation

Pros:

¾Decrease the complexity of today’s Internet infrastructure

Cons:

¾ Absence of any end-user information and other valuable context information of Internet client

¾ Affect underlying network performance

I.

Motivation

Context-Aware Computing Cognitive Science

Context Application Layer Context Middleware Layer Context Sensing Layer Context-Aware Service Context Database and File System

Virtual Sensors Physical Sensors

External Context Provider Internal Context Provider Context Engine and Model

I.

Motivation

We propose to de-conflate end-user, networked host and Internet service on the Internet client side, and explicitly incorporate the relevant context information into the Internet protocol stack.

I.

Motivation

1. What context information is required for the Internet protocol stack? How to capture them?

2. How does the Internet protocol stack utilize and even adapt itself to the captured context information?

3. How to motivate selfish Internet clients to share their actual context information?

II.

User

‐

Context

Module

Design

Key Context Information

Context Sensing Subsystem

Basic Context

Information Key Context Information

Group Key Context Information

Internet Client

II.

User

‐

Context

Module

Design

II.

User

‐

Context

Module

Design

II.

User

‐

Context

Module

Design

II.

User

‐

Context

Module

Design

Context Model Subsystem – End-User Modeling

Perceptual Processor Feedback Perceptual Subsystem Senses Visual Image Storage Auditory Image Storage Long-Term Meomory Working Memory Cognitive Processor Motor Processor Actuator (arm-hand-finger system, sound, etc) Motor

Subsystem Cognitive Subsystem

II.

User

‐

Context

Module

Design

Context Model Subsystem – End-User Modeling

Two important end‐user states with any individual Internet service:

¾ User Perception State: Both the end‐user’s Perceptual and Cognitive subsystems are turned ON to acquire and process the information of the corresponding Internet service.

¾ User Halt State: The end‐user’s three subsystems, i.e., the Perceptual, Cognitive and Motor subsystems, are all turned OFF with the corresponding Internet service.

II.

User

‐

Context

Module

Design

Define

two

basic

categories

of

Key

Context

Information

(KCI):

¾ COMMUNICATING STATE (CS): The end‐user stays in the

User Perception State AND the corresponding Internet service

keeps working.

¾

INACTIVE STATE

(

IS

):

OR the corresponding Internet service stops working.

II.

User

‐

Context

Module

Design

II.

User

‐

Context

Module

Design

Context Model Subsystem – Context Models

II.

User

‐

Context

Module

Design

Control Subsystem

¾ The Control Subsystem directly interacting with the underlying

Internet and adjust it according to the delivered KCI.

¾ For different applications of the User‐Context Module, the

Control Subsystem may interact with different Internet protocols and services in distinct layers.

¾ Its main objective is always to improve the usability and

III.

The

User

‐

Context

Module

Application:

HTTP

III.

The

User

‐

Context

Module

Application:

HTTP

Problem

Description

HTTP/1.1* does not define the connection‐closing mechanism

¾Small fixed timeout value causes low utilization of the HTTP

connection, increases the end‐user perceived latency and

network burden. (Apache HTTP Server ‐‐‐ 5 seconds)

¾Large fixed timeout value easily exhausts busy Web server

resources, causes instability and unpredictable long end‐user

perceived latency. (Microsoft IIS ‐‐‐ 120 seconds)

III.

The

User

‐

Context

Module

Application:

HTTP

Problem

Description

In a Web session, it is difficult for HTTP to discriminate

between a persistent connection that is being used by

an Web end

‐

user and a persistent connection that is

III.

The

User

‐

Context

Module

Application:

HTTP

Problem

Solution

Key Context Information

Context Sensing Subsystem

Basic Context

Information Key Context Information

Group Key Context Information

III.

The

User

‐

Context

Module

Application:

HTTP

III.

The

User

‐

Context

Module

Application:

HTTP

The following Control Rules is implemented on the server side:

(1) IF the Inactive State arrives, THEN the Control Subsystem

immediately signals the Application Layer to terminate the

corresponding HTTP persistent connection.

(2) IF the Communicating State arrives, THEN the Control

Subsystem signals the Application Layer to maintain the

corresponding HTTP persistent connection and wait for the next KCI.

III.

The

User

‐

Context

Module

Application:

HTTP

Internet

Experiment

Setup

Modified Apache HTTP Server 2.2

III.

The

User

‐

Context

Module

Application:

HTTP

Internet

Experimental

Results

III.

The

User

‐

Context

Module

Application:

HTTP

III.

The

User

‐

Context

Module

Application:

HTTP

Internet

Experimental

Results

III.

The

User

‐

Context

Module

Application:

HTTP

III.

The

User

‐

Context

Module

Application:

TCP

It has been proved that when multiple TCP streams compete the same bottleneck link, the stream with a smaller round trip time (RTT) can always grab a much larger share of that bottleneck link bandwidth than other streams with larger RTT.

III.

The

User

‐

Context

Module

Application:

TCP

TCP protocol always favors an Internet application with a short RTT and inevitably ignores the end-user preference. Hence, such property of TCP can easily impair the end-user’s quality of experience (QoE).

III.

The

User

‐

Context

Module

Application:

TCP

Problem

Description

Quality of Experience (QoE): the overall acceptability of an

application or service, as perceived subjectively by the end-user*.

*ITU-T. Rec. P. 10 /G. 100, Amendment 2: New Definitions for Inclusion in Recommendation ITU-T P.10/G.100, 2008.

**P. Brooks and B. Hestnes, “User measures of quality of experience: why being objective and quantitative is important,” IEEE Network, vol. 24, no. 2,pp. 8–13, 2010.

IF <Communication Situation>; USING <Service Prescription>; WITH <Technical Parameters>; THEN <QoE in Opinion Score>.

III.

The

User

‐

Context

Module

Application:

TCP

Problem

Solution

Key Context Information

Context Sensing Subsystem

Basic Context

Information Key Context Information

Group Key Context Information

III.

The

User

‐

Context

Module

Application:

TCP

Advertised window size determined by the spare room of the receiver buffer.

III.

The

User

‐

Context

Module

Application:

TCP

W

V

RTT

=

W --- Advertised window size in bits set by the TCP receiver RTT --- Average round trip time of a TCP flow in seconds

TCP Flow Control Mechanism

The established mathematical model:

III.

The

User

‐

Context

Module

Application:

TCP

The

Control

Subsystem

Design

III.

The

User

‐

Context

Module

Application:

TCP

The

Control

Subsystem

Design

The following Control Rules is implemented on the client side:

(1) IF the Communicating State between the end-user and

QQQTV is deduced and meanwhile the QQQTV bandwidth share is lower than 320 Kbps, THEN the Control Subsystem

immediately reduces the advertised window size of

CuteFTP until QQQTV bandwidth share exceeds 400 Kbps.

(2) IF the Inactive State between the end-user and QQQTV is

III.

The

User

‐

Context

Module

Application:

TCP

Adjust the advertised window size by discrete PD (Proportional and Derivative) control algorithm:

( ) ( ( ) ( 1)), rec k P d W K e k K e k e k Δ = + − − rec k W

Δ --- controller output at the kth sampling time

--- target bandwidth given by the Control Rules

R

k

V --- practical allocated bandwidth at the kth sampling time

The

Control

Subsystem

Design

( ) _k.

III.

The

User

‐

Context

Module

Application:

TCP

III.

The

User

‐

Context

Module

Application:

TCP

Internet

Experimental

Results

Scenario A: CuteFTP is always associated with the Inactive State, which means the end-user is unaware of CuteFTP downloading from the beginning to the end.

III.

The

User

‐

Context

Module

Application:

TCP

3. How to motivate context sharing?

(This part of work is still unpublished, and thus the

corresponding slides are removed. )

Summary

&

Summary

Internet Protocol Stack Conventional communication pathway: from the Internet protocol stack through Internet services to the end-user side.

Summary

We add a novel communication pathway for transmission of context, and establish a closed communication loop.

Summary

Main Contributions:

¾Reveal the fact that context information can be directly used in

the underlying Internet protocol stack.

¾Design and implement a User-Context Module that can capture,

understand and utilize the context information of Internet clients.

¾ Propose a resource distribution framework that not only provides

the context-driven service differentiation, but also incentivizes

the actual context sharing and moderate competition among selfish and rational Internet clients.

Future

Directions

Advanced context models and approaches for new KCI:

¾Introduce latest cognitive psychology, brain-computer

interface (BCI) as well as neuroscience for building more accurate context models.

¾Adopt data mining and machine learning algorithms to

automatically derive long-term end-user’s interaction patterns. (One of our conference papers adopts decision tree C4.5 to derive the context model.)

Future

Directions

More applications of the existing User-Context Module:

¾Explore interactions with many other communication protocols in different layers, such as Real Time Streaming Protocol (RTSP) on the Application Layer and Internet Protocol Security (IPsec) on the Network Layer.

¾Implement the resource distribution framework on more Internet systems and services, such as Streaming Media System.

Future

Directions

Context usage in future Internet architecture:

¾Introduce the deduced KCI into architectures of next generation Internet that use the clean-slate design approach, such as in the identifier-locator split architecture*.

¾Design a set of application programming interfaces (API) that any future protocols could use to extract the captured context information.

Selected journal papers:

Yu Lu, Motani Mehul and W. C. Wong, “When Ambient Intelligence Meets the

Internet: User Module Framework and its Applications,” Elsevier Journal of

Computer Networks, 2012. (accepted and to appear)

Yu Lu, Motani Mehul and W. C. Wong, “A Resource Distribution Framework

Incentivizing Context Sharing and Moderate Competition,” submitted to

IEEE/ACM Transactions on Networking.

Jinkun Liu, Yu Lu, “Adaptive RBF neural network control of robot with actuator

nonlinearities,” Springer Journal of Control Theory and Applications, vol. 8, no. 2,

pp. 249-256, 2010.

Peng Li, Yu Lu, Shen Li and Hongxing Wei, “Realization of Embedded Multimedia

System Based On Dual-Core Processor OMAP5910,” International Journal of

Selected conference papers:

Yu Lu, Motani Mehul and W. C. Wong, “The User-Context Module: A New

Perspective on Future Internet Design," in Proc. International Conference on

Ambient Systems, Networks and Technologies (ANT), Niagara Falls, Ontario,

Canada, Sept., 2011.

Yu Lu, Motani Mehul and W. C. Wong, “When Ambient Intelligence Meets Internet

Protocol Stack: User Layer Design," in Proc. IEEE International Conference on

Embedded and Ubiquitous Computing (EUC), Hong Kong SAR, China, Dec.,

2010.

Yu Lu, Motani Mehul and W. C. Wong, “Intelligent Network Design: User Layer

Architecture and its application," in Proc. IEEE International Conference on