MIS6120 - Notes#2 - Mobile Computing Architecture

7/23/2019 MIS6120 - Notes#2 - Mobile Computing Architecture

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Mobile

Computing

Tata McGraw Hill

Notes#2

Mobile ComputingArchitecture

MIS 6120 Gerald Chege


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History of Computers - I

German engineer Konrad Zuse developed a computer called Z3 to

design airplanes and missiles in 191 during !orld !ar ""

"n 193$ the %ritish developed a computer called Colossus &orcr'ptanal'sis to decode encr'pted messages transacted b' Germans

"n 19$ (o)ard ( Ai*en developed the (arvard + "%MAutomatic ,e-uence Controlled Calculator Mar* "$ or Mar* " &orshort

.lectronic Numerical "ntegrator and Calculator$ better *no)n as

.N"AC$ )as developed b' /ohn 0 .c*ert and/ohn ! Mauchl' in19

"n 19$ /ohn von Neumann introduced the concept o& storedprogram



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History of Computers - II

"n 19$ the invention o& the transistor b' / %ardeen$ !alter (%rattain$ and !illiam ,hoc*le' at %ell 4abs changed thedevelopment scenario o& digital computers 5he transistor replacedthe large$ energ' hungr' vacuum tubes in &irst generation computers

/ac* Kilb'$ an engineer )ith 5e6as "nstruments$ developed the"ntegrated Circuit 7"C8 in 19

%' the 19:;s$


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History of Internet I

@ollo)ing the success&ul launch o& ,putni* in 19 b' theussians$ B,A &elt the need o& research in certain &ocused areas5here&ore$ Advance esearch 0roect Agenc' 7A0A8 )as&ormed to &und ,cience and 5echnolog' proects and positionB,A as a leader in technolog'

"n earl' si6ties$ 4eonard Kleinroc* developed the basicprinciples o& pac*et s)itching at M"5

During the same period$ 0aul %aran in a series o& ANDCorporation reports recommended several )a's to accomplish

pac*et s)itch net)or*

"n 19$ )or*ing )ith 5homas Merrill$ 4a)rence G obertsconnected the 5E + 2 computer in Massachusetts to the F32 inCali&ornia )ith a lo) speed dial + up telephone line creating the&irst computer net)or*MIS 6120 Gerald Chege


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History of Internet II

"n 191$ a' 5omlinson at %%N )rote the so&t)are to send and

read simple electronic mail

"n Hctober 192$ demonstration o& the A0AN.5 )as done atthe "nternational Computer Communication Con&erence 7"CCC85his )as the &irst public demonstration o& this ne) net)or*technolog' to the public "t )as also in 192 that the initial IhotIapplication + electronic mail$ )as introduced

"n 19$ the B, N,@ initiated the development o& the N,@N.5)hich provided a maor bac*bone communication service &or the"nternet

"n .urope$ maor international bac*bones such as NHDBN.5and others provided connectivit' to a large number o& net)or*s"nternet slo)l' evolved as the universal net)or* o& net)or*s$)hich connects almost ever' data net)or*s o& the )orld )ith areach spread over the )hole o& earthMIS 6120 Gerald Chege


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History of Internet III

Hn Hctober 2th$ 199$ the @NC unanimousl' passed a resolutionto o&&iciall' de&ine the term "nternet According to this resolution$the de&inition o& "nternet is J"nternet re&ers to the globalin&ormation s'stem that + 7i8 is logicall' lin*ed together b' agloball' uni-ue address space based on the "nternet 0rotocol 7"08or its subse-uent e6tensions &ollo) + onsL 7ii8 is able to support

communications using the 5ransmission Control 0rotocol "nternet0rotocol 75C0"08 suite or its subse-uent e6tensions &ollo) +ons$ and or other "0 +compatible protocolsL and 7iii8 provides$uses or ma*es accessible$ either publicl' or privatel'$ high levelservices la'ered on the communications and related in&rastructure

described herein


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During 19:s$ D .ngelbart protot'ped an IoN4ine ,'stemI

7N4,8 that does h'perte6t bro)sing$ editing$ etc (e invents the

mouse &or this purpose

"n 1991$ 5im % 4ee invented ('per 5e6t Mar*up 4anguage7(5M48 and ('per 5e6t 5ransport 0rotocol 7(5508 5im )rote a

client program and named it as J!orld !ide !eb$ )hich &inall'

became the J))) 7!orld !ide !eb8 and became almost

s'non'mous )ith "nternet

History of Internet IV



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Internet The Ubiquitous Network

5)o ubi-uitous net)or*s + the telecommunications net)or* and

the "nternet

Glue &or telecommunications net)or* + ,,# 7loosel'8

Glue &or the "nternet + 5C0"0

5hree basic t'pes o& content + audio$ video and te6t

5hree main segments o& an' net)or* + Core$ .dge and Access

Core + bac*bone o& net)or* and loo*s at the tra&&ic &rom the

stream o& bits point o& vie)

.dge + responsible &or the distribution o& tra&&ic and loo*s at the

tra&&ic &rom the service point o& vie)

Access + deals )ith last mile o& transmission



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Architecture of Mobile Computin

5he three tier architecture contains the user inter&ace or the

presentation tier$ the process management or the application tier

and the data management tier



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Mobile Computin Architecture



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!resent"tion Tier

esponsible &or presenting the in&ormation to the end user

un on the client device and o&&er all the user inter&aces

"ncludes )eb bro)sers$ !A0 bro)sers and client programs



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Applic"tion Tier

"ndependent o& presentation and database management

(andles &unctions related to middle)are

Middle)are + la'er o& so&t)are sitting bet)een the operatings'stem and user &acing so&t)are

Man' t'pes o& middle)are + Message Hriented Middle)are$

5ransaction 0rocessing Middle)are$ Communication

Middle)are$ Distributed Hbects and Components$ 5ranscodingMiddle)are$ !eb ,ervices$ etc



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Mess"e #riente$ Mi$$lew"re

4oosel' connects di&&erent applications through as'nchronous

e6change o& messages

!or*s independent o& plat&orm or processor con&iguration

Generall' as'nchronous and peer to peer

!or*s in publish subscribe &ashion

.6amples + MF series &rom "%M$ /M,$ etc



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Tr"ns"ction !rocessin Mi$$lew"re

0rovides tools and environment &or developing transactionbased distributed applications

Capable o& providing services to thousands o& clients in a

distributed client + server environment

"ndependent o& database architecture

.6ample + C"C, &rom "%M



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Communic"tion Mi$$lew"re

Bsed to connect one application to another

Fuite use&ul in the telecommunications )orld

Bses mediation server to automate the telnet protocol to

communicate to nodes in the net)or*

.6ample + Bsing telnet to connect one application to another



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%istribute$ #b&ects "n$ Components

(andles open distributed obect computing in&rastructure

.6ample + Common Hbect e-uest %ro*er Architecture 7CH%A8

CH%A + a vendor independent in&rastructure

CH%A + highl' interoperable across heterogeneous plat&orms



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Tr"nsco$in Mi$$lew"re

Bsed to transcode one &ormat o& data to another suiting the needs

o& the client

Bse&ul &or content adaptation to &it the needs o& device.6ample + "nternet Content Adaptation 0rotocol 7"CA08 &rom

".5@



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ICA!

Aimed at providing simple obect based content vectoring &or

(550 services

4ight)eight protocol to do transcoding on (550 messages

,imilar to e6ecuting a 0C on a (550 re-uest

Adapted messages can either be (550 re-uests or (550

responses



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%"t" flow in "n ICA! en'ironment

1. A user agent makes a request to an ICAP-capablesurrogate (ICAP client) for an object on an origin

server.2. !e surrogate sen"s t!e request to t!e ICAPserver.

#. !e ICAP server e$ecutes t!e ICAP resource%s

service on t!e request an" sen"s t!e possibl&Continue"MIS 6120 Gerald Chege


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*. !e surrogate sen"s t!e request possibl& "i+erentfrom t!e original client request to t!e origin server.

,. !e origin server respon"s to t!e request.

. !e surrogate sen"s t!e repl& (from eit!er t!e ICAPserver or t!e origin server) to t!e client.



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(eb )er'ices

0rovides a standard means o& communication and in&ormation

e6change among di&&erent so&t)are applications

0ublic inter&aces and bindings are de&ined using EM4

,tandards &or service re-uestor and service provider

,ervice re-uestor + &ind and discover the description o& services

,ervice provider + publish the description o& services it provides



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%"t" Tier

Bsed to store data needed b' the application and acts as a

repositor' &or both temporar' and permanent data

Can use EM4 &or interoperabilit' o& data )ith other s'stems

and data sources

Might incorporate the use o& Database Middle)are and

,'ncM4

Database Middle)are + inter&aces application programs and the

databaseDatabase Middle)are + helps business logic run independent

and transparent &rom database technolog' and database vendor


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)yncM*

.merging standard &or s'nchroni=ation o& data access &rom

di&&erent nodes

0romotes a single common data s'nchroni=ation protocol that

can be used industr' )ide

,upports naming and identi&ication o& records and common

protocol commands to s'nchroni=e local and net)or* data

!or*s over all net)or*s used b' mobile devices + )ired and

)ireless


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%esin Consi$er"tions

Conte6t in&ormation is the in&ormation related to thesurrounding environment o& an actor in that environment

Mobilit' implies that attributes associated )ith devices and

users )ill change constantl'

,uch changes shall mean that content and behavior o&

applications should be adapted to suit the current situation

,ome e6amples are>

1 Content )ith conte6t a)areness2 Content s)itch on conte6t

3 Content transcoding on conte6t


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Concernin conte+ts in Mobile Computin

5he &ollo)ing conte6ts need to be ta*en care o&>

Bser conte6t

Device conte6t

Net)or* conte6t

%and)idth conte6t

4ocation conte6t

5ime conte6t

.nvironment conte6t

Charging conte6t

,ecurit' conte6t


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H"n$lin user conte+t

!ho is the user

"n 5rusted 0ersonal Devices 750D8$ and certain des*top

environments user can be assumed &rom a particular environment @or e6ample$ an'bod' &rom B,"B can access the digital librar'

"n general$ des*tops are shared devices and user conte6t is

d'namic


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H"n$lin $e'ice conte+t

!hat is the device behavior!hat is the displa' si=e

Does it support color

Does it support ,'ncM4

!hat bearers it supports

"s there an' shared obect bet)een applications in device

and server

Can )e identi&' the device )ithout ambiguit' 7li*e "M."8


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H"n$lin network conte+t

!hat is the securit' polic' in the net)or*

!hat are the available bearers in the net)or*

!hat are the di&&erent nodes in the net)or*

Does the net)or* o&&er positioning in&ormation

!hat are the di&&erent services available )ithin the net)or*

!hat are the services the user has subscribed to


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H"n$lin b"n$wi$th conte+t

!hat is the band)idth available &or this net)or*

!hat is the band)idth the subscriber is allo)ed to

"s there an' service level agreement on band)idth bet)een the

user and net)or*

!ho pa's &or the band)idth


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H"n$lin loc"tion conte+t

Can )e locate the device

!hat is the positioning in&ormation 7@or e6ample$ is the car

&acing north )a' or south )a' in the high)a'8


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H"n$lin time conte+t

Can )e identi&' the time=one o& the client

Can )e get the timestamp o& the client

Can )e s'nchroni=e the cloc*

0roviding in&ormation based on time @or e6ample$ " &inish m'

meeting at >:: 0M$ the s'stem can tell me that " can visit a

museum and the close b' a-uarium &ollo)ed b' dinner in a

Chinese restaurant


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H"n$lin en'ironment conte+t

!hat are the environmental conditions o& the surrounding

.ssential &or sensor based net)or*s

.ssential &or telematic applications

.ssential &or embedded s'stems


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H"n$lin ch"rin,billin conte+t

!ho pa's &or this service

(o) to collect the usage in&ormation

!hom to send the in&ormation &or billing the end user

!hat are the principles o& sharing the revenue )ith other

service providers


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H"n$lin security conte+t

!hat is the securit' conte6tCan )e authenticate the device

Can )e authenticate the user o& the device

"s the net)or* trusted "& not$ )hat is re-uired to build the

trust"s the net)or* encr'pted

!hat t'pes o& encr'ption does the client support

Does the client have a !"M 7!ireless "denti&ication Module8

Does the client have a private *e'


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Content "rchitecture in Mobile Computin


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Client Conte+t M"n"er CCM.

Maintains in&ormation pertaining to>

1 Mobile devices

2 Bsers3 4ocation

Net)or*

.nvironment around each mobile device


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Ch"llenes with CCM

Conte6t de&inition> De&ining conte6t attributes )ithinteroperabilit' in mindL ho) )ill ever' G0, device *no) thecurrent data &ormat

Conte6t sensing> 5he )a' conte6t data is obtainedL eg G0,data ac-uisition

Conte6t representation> 5he )a' conte6t in&ormation is storedand transportedL eg transmitting such in&ormation

Conte6t interpretation> 5he )a' the conte6t data isinterpretedL eg )e might need additional G", in&ormation tointerpret the G0, data


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Conte+ts h"n$le$ by CCM

"dentit'

,patial and temporal in&ormation

.nvironmental in&ormation

,ocial in&ormation0ro6imit' and availabilit' o& resources

0h'siological measurements

Activit'

,chedules and agendas


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/unctions of the CCM

esponsible &or receiving ra) conte6t data$ collating the datainto a use&ul &orm and disseminating it to conte6t consumers

0resent conte6t in&ormation to consumers in suitable and

interoperable &orm

Conte6t model should allo) aggregation

D'namic updates should be possible

Conte6t histor' should be available

Conte6t should be &ilteredMIS 6120 Gerald Chege

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Composite C"p"bilities,!reference !rofiles

0roposed !3C standard &or describing device capabilities and

user pre&erences

%ased on esource Description &rame)or* 7D@8

Can be seriali=ed using EM4

Hrigin server or pro6' can per&orm some sort o& content to

device matching

Abbreviated as CC00


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CC,!! in "ction

Device sends seriali=ed pro&ile model )ith re-uest &or contentHrigin server receives seriali=ed D@ pro&ile and converts it

into an in + memor' model

5he pro&ile &or the re-uested document is retrieved and an in +

memor' model is created

5he device pro&ile model is matched against the document

pro&ile model

A suitable representation o& the document is chosen .ither

content s)itch on conte6t or content transcoding on conte6t is

emplo'ed

Document is returned to device and presented


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)implest use of CC,!!


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/orm"t for 0%/


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1+"mple for 0%/


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!"rser for 0%/

/ava based D@ parser 7,i0AC8 is available &ree on the )eb

,i0AC can be used to parse serialised D@ into triples

5riples are the output o& D@ parsers and are o& the &orm triple7subect$ predicate$ obect8

Bsing triples$ it is possible to build a CC00 model 5he modelis updated )henever ne) conte6t data are sent &rom conte6tsources


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!olicy M"n"er

esponsible &or controlling policies related to mobilit'

,hould be able to de&ine polic' &or documentsservices and

assign roles to user

,hould assign roles to users li*e

0ermission

0rohibition

Hbligations

0olic' combined )ith conte6t should determine

)hat action7s8 the user is allo)ed to per&orm

)hat action7s8 the user is obliged to per&orm

the polic' applicable


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)em"ntic (eb

@acilitates putting machine understandable data on the )eb

@acilitates )eb de&inition and lin*ing in a )a' to be use&ul &or

machines in the conte6t o& automation$ securit'$ &iltering$

integration and data reuse"ncreases the modularit' o& )eb applications

%uilt on s'nta6es )hich use B"?s to represent data

,uch s'nta6es are called esource Description @rame)or*7D@8 s'nta6es


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)ecurity M"n"er

,ecures connection bet)een client device and origin server

,hould handle

Con&identialit' 7managed b' encr'ption8

"ntegrit' 7managed b' algorithms8 Availabilit' 7relates to peripheral securit'8

Non + repudiation 7managed b' digital signatures8


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!l"tform for !ri'"cy !reference !ro&ect

.merging standard de&ined b' !3C

.nables )ebsites to e6press their privac' practices in a

standardi=ed &ormat retrievable and interpretable b' user

agents

An' discrepancies bet)een a site?s practices and the user

pre&erences can be &lagged as )ell

Does not provide an' mechanism &or ensuring that )ebsites

act according to their policies

"ntended to be complementar' to both legislative and sel&+

regulator' programmes


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A$"pt"bility M"n"er

%ased on conte6t and polic' $ it should adapt to>

Content

%ehaviour

Hther aspectsMa' ta*e an' number o& actions depending upon the

in&ormation passed to it b' Conte6t Manager

Ma' include appending location + speci&ic in&ormation to

documents


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Content "$"pt"tion

Content should be able to adapt to d'namic situations

Adaptation can be static or d'namic

Content adaptation can be per&ormed either at content level in

server or agent level in client

Content adaptation can be handled b' middle)are as )ell

Content adaptation needs to consider the ph'sical and logical

capabilities o& the device$ e&&ective net)or* band)idth andpa'load 7total number o& bits delivered to the agent &or static

parts8


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Content tr"nsco$in

5he resource re-uirements &or the client devices can be determinedb'>

,tatic content si=e in bits

Displa' si=e,treaming bit rate

Colour re-uirements

Compression &ormats

(ard)are re-uirements


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Types of content tr"nsco$in

,patial transcoding

5emporal transcoding

Colour transcoding

Code transcoding

Hbect or semantic transcoding


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Content r"tin "n$ filterin

Need to ensure social discipline in the electronic )orld

0lat&orm &or "nternet Content ,election 70"C,8

0"C, + !3C proposed standard &or )eb content rating

0"C, + set o& technical speci&ications &or labels that helpso&t)are and rating services to )or* s'nergisticall'

0"C, + services should choose their o)n criteria &or proper

identi&ication and &iltering o& content

ating can be through sel& labeling or third part' labeling

Hriginall' designed to help parents and teachers control children

access to the "nternet

Also includes code signing and privac'


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0)ACI

Acron'm &or ecreational ,o&t)are Advisor' Council + "nternet

(as a 0"C, compliant rating s'stem called esaca

esaca has &our categories + violence$ nudit'$ se6 and language

(as a rating range &rom : to

: means no potentiall' o&&ensive content

means highest level o& o&&ensive content

0"C, + a general meta data s'stem

0"C, labels + help&ul in &inding desirable content on the )eb

0"C, + enables more sophisticated commerce$ communication$

inde6ing and searching servicesMIS 6120 Gerald Chege

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Content Are"tion

@rom the content aggregator?s perspective$ services are o& t)ocategories>

,ingle service re-uest + )or*s at user level and &or one user

.6ample > A user ma' re-uest a )ebpage in Chinese &rom pro6'

server (ere$ the user bu's both the content and translation service

Group service re-uest + )or*s &or a group o& users

.6ample > 5he content aggregator has some arrangement &oradvertisement "t e6amines all (5M4 pages and inserts an

advertisement at an appropriate place


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)e"mless Communic"tion

A ubi-uitous s'stem involves availabilit' and accessibilit' &roman')here$ an'time and through an' net)or* or device

,eamless communication shall involve seamless handovers and

seamless roaming

(ando&& is the process b' )hich the connection to the net)or*

is moved &rom one base station to another )ithin the same

net)or* )ithout discontinuing the service

oaming shall involve the point o& attachment moving &rom onebase station o& one net)or* to a base station o& another net)or*


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Aspects of )e"mless Communic"tion

Authentication across net)or* boundaries

Authori=ation across net)or* boundaries

%illing and charging data collection

.nd + to + end data securit' across roaming

(ando&& bet)een )ireless access points

oaming bet)een net)or*s

,ession migration

"0 mobilit'


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Autonomous Computin

5he purpose o& autonomous computing is to &ree users and s'stem

administrators &rom the details o& the s'stem operation and

maintenance comple6it' "t combines the &ollo)ing &unctions>

,el& con&igurable

,el& optimi=ing

,el& healing

,el& protecting

,el& upgradable


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Conte+t "w"re systems

5he &ollo)ing in&ormation needs to be handled in a mobilecomputing environment &or ma*ing a s'stem conte6t a)are>

4ocation in&ormation

Device in&ormationNet)or* in&ormation

Bser in&ormation

.nvironment in&ormation


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2lob"l !ositionin )ystem

Gives the e6act positioning on .arth

@unded and controlled b' B, Department o& De&ense

(as three parts + the space segment$ the user segment and

control segment

(as 2 satellites $ each in its o)n orbit 11$::: nautical miles

above .arth


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M"kin e+istin "pplic"tions mobile en"ble$

.nhancing an e6isting application

enting an application

Developing a ne) application

%u'ing a pac*aged solution

%ridging the gap through middle)are


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Ne+t Topic

Mobile Computin throuh

Telephony

MIS6120 - Notes#2 - Mobile Computing Architecture

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