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Technology of cellular CDMA and of GSM


Technological History of mobile In Indonesia, business liberalisms of cellular started since year 1995, governmental moment start opening opportunity to private sector for have business to phone cellular by competition full. Can be paid attention, how when technology of GSM (global mobile for system) come and replace technology of cellular first generation which have entered previously to Indonesia like NMT (telephone mobile nordic) and AMPS (advance of mobile system phone). When in year 1980-an, Global technology of System For Mobile Communication (GSM) come to Indonesia, hence all technological user operator of AMPS (Advanced Mobile Phone System) disappearing is. Last, emerge Satelindo as winner, what is later caught up by Telkomsel. And technological in the end GSM more pre-eminent and growth of mushroom basin in the rains, this because of higher network capacities, because efficiency in frequency spectrum from at technology of NMT and of AMPS.




Now, in range of time almost one decade, technological of GSM have mastered market with amount of customer / client more than the amount of customer / client of telephone remain to. In Indonesia, business liberalisms of cellular started since year 1995, governmental moment start opening opportunity to private sector for have business phone cellular by competition full. Can be paid attention, how when technology of GSM (global of mobile for system) come and replace technology of cellular first generation which have entered previously to Indonesia like NMT (telephone mobile nordic) and AMPS (advance of mobile system phone).


When year 1980-an, Global technology of System For Mobile Communication (GSM) come to Indonesia, hence all technological user operator of AMPS (Advanced Mobile Phone System) disappearing is. Last, emerge Satelindo as winner, what [is] later;then caught up by Telkomsel. And technological in the end GSM more pre-eminent and growth of mushroom basin in the rains, this because of higher network capacities, because efficiency in frequency spectrum from at technology of NMT and of AMPS.


Technological application

There are some technology without cable for the technology of this cellular, among others is :

  • CDMA (Code Division Multiple Access), using technology of spread-spectrum to circularizing information signal which passing wide bandwidth (1,25 MHZ). Technological this come from him made by for the sake of military, using unique digital code, better than frequency or channel of RF.

  • AMPS (Advanced Car of Phone Service) representing analogous technology which use FDMA (Frequency Division Multiple Access) to assort available radio bandwidth to at a number of district channel which remain to. With AMPS, bandwidth 1,25 MHZ given for the usage of cellular divided to become channel widely 30 KHZ, each can only serve one subscriber at one time. One subscriber access a channel hence do not other subscriber can access the channel until first call that desist or handed-off to base of station other.

  • TDMA (Time Division Multiple Data), representing a digital technology, is the same as that is by assorting available spectrum to a number of district channel which remain to, though each slot time showing channel which remain to than band frequency which remain to. For example which is technological implementation of TDMA is GSM, dividing wide carriers 2300 KHZ become eight channel time-division. GSM (global system of for mobile) is technology being based on TDMA.

  • UMTS (Universal of Mobile Telecommunication Access) representing is wrong of third generation system which developed in Europe. Designed so that can provide bandwidth equal to 2 Mbits / s. Service able to be given by UMTS strived can fulfill request of user anywhere reside in, its meaning of UMTS expected can serve area which for the width of possible, if there no UMTS cell at one particular area earn in route pass satellite. Radio Frequency which is allocation for UMTS is 1885-2025 MHZ and 2110-2200 MHZ. Ribbon the will be used by small cell (pico cell) so that can give capacities big at UMTS.


Technological of CDMA

Technological of CDMA the design is not sensitive to interference. Despitefully, a number of customer / client

in one cell can access frequency spectrum ribbon concurrently because utilizing code technique which cannot be conducted by at technology of GSM. Higher level Capacities to overcome the more call which is simulate per channel compared to existing system. System of CDMA offer the make-up of capacities exceed system Analogous AMPS as good as other digital cellular technology. CDMA yield a scheme of spread spectrum what at random provide bandwidth 1.250 KHZ which available to caller 9600 beet bps of rate.

improving security call.

Security become the nature of from approach of CDMA spectrum spread, and its this technological woke up first to provide peaceful communications to military. Reducing and noise of interference other. CDMA boost up ratio of signal-to-noise, because width of bandwidth which available to message. Energy Efficiency by lengthening energy live telephone battery One of the characteristic of CDMA is control power a effort to enlarge capacities call with constant maintaining of accepted energy level of caller peripatetic at base of station. facility of coordination entire / all frequency pass base base-station of station.

System of CDMA provide hand-off soft from one base-station to other as a peripatetic telephone roaming of cell to cell, conducting handoff soft remember all systems using is same frequency. function of Spread-Spectrum and of power-control enlarging capacities call CDMA resulting bandwidth which last for all kinds of data service of multimedia, and scheme of soft hand-off guarantee do not the loss of data.

  • Improving the quality of voice

  • Improve coverage characteristic able to degrade the amount of cell

  • Improving and privacy of security

  • Making moderate planning of systems

  • Needing lower remittance, so that time speak phone cell earn longer

  • Lessening interference at other systems

  • More hold up to multipart

  • Can be operated at the same time with other technology (for example AMPS)


Elementary difference of technology of GSM and of CDMA

Elementary difference of technology of CDMA is its modulation system. Modulation of CDMA representing combination of FDMA (Frequency of Division Multiple Access) and TDMA (Time Division Multiple Access). At technology of FDMA, 1 frequency canal serve 1 circuit at one time, while at TDMA, 1 frequency canal wearied by some consumer by slot different time. At CDMA some consumer can serve when at the same time and is same frequency, where differentiation one other is on system of coding, so that usage its frequency spectrum of technology of CDMA very efficient.

Excess which on the market CDMA for example quality of data and voice, tariff or price which is cheaper, smaller investment, and security in communicating (do not easy to tapped). Technology of GSM with its GPRS is competed with content at CDMA because limitation will be wide of application and data of multimedia at technology of GSM.


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What is graphical design ?


Definition of graphical design

Graphical design is one of the artistic form of paint giving freedom to the designer to chosen, to creating, or arranging aspect element like illustration, photo, article, and line above an surface with a purpose to be produced and communicated as a message. Picture and also sign used can in the form of other media or typography like or picture of photography. Design graphical is generally applied in the world of advertisement, packaging and others.




Category of graphical design

Marginally, differentiated graphical design to become some category :

  1. Printing : loading book design, magazine, poster, booklet, leaflet, flyer, pamphlet, advertisement, and other publication which of a kind.

  2. Web design : design for the page of web

  3. Film : including CD, DVD, CD Multimedia for promotion.

  4. Identify (Logo), EGD (Environmental Graphic Design) : representing professional design which include cover graphical design, architect design, industrial design, and garden architect.

  5. Product Design : Package and of a kind.


Program processor of graphical

  1. Application processor arrange situation (layout)

- Adobe FrameMaker

- Adobe In Design

- Adobe PageMaker

- Corel Ventura

- Microsoft Publisher

- Quark Xpress


  1. Application processor of vector / line

- Adobe Illustrator

- Beneba Canvas

- CorelDraw

- Macromedia Freehand

- Metacreations Expression

- Micrografx Designer


  1. Application processor of pixel / picture

- Adobe Photoshop

- Corel Photo Paint

- Macromedia Xres

- Metacreations Painter

- Metacreations Live Picture

- Micrografx Picture Publisher

- Microsoft Photo Editor

- QFX

- Wright Image


  1. Application processor of film / video

- Adobe After Effect

- Power Director

- Show Biz DVD

- Ulead Video Studio

- Element Premier

- Easy Media Creator

- Pinnacle Studio Plus

- WinDVD Creater

- Nero Ultra Edition


  1. Application processor of multimedia

- Macromedia

- Macromedia Authorware

- Macromedia Director

- Macromedia Flash

- Multimedia Builder

- Ezedia

- Hyper Studio

- Ovation Studio Pro

- Macromedia Director

- Macromedia Flash

- Multimedia Builder

- Ezedia

- Hyper Studio

- Ovation Studio Pro


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Variable And Type Data


Language of programming in general, recognizing the existence of variable used for save assess or data. While Java alone known as language of programming with nature of typed strongly with the meaning obliged data type declaration from all variable, and if forgetting or wrong follow variable declaration order, hence will get error at the (time) of process compiles.



  1. Type Data

Java have data type able to be categorized to become two group, that is primitive data type and reference.

1. Primitive Type Data

Eight kinds of primitive data type in programming of Java, that is :

    • Integer (Integer )

Integer represent data type of numeric used if do not deal with number or fraction denary. Integer number usually use int, and non byte, and also short of long. Integer number also recognize positive value and negativity (number signed). Data type of byte and of short only used at special application which pay attention usage of memory. While long seldom be used by because seldom need number equal to capacities of long.

    • Floating Point (Number Fraction)

Floating Point used to handle number denary or more calculation of detail compared to integer.

    • Char

Char is single character which defined with early and terminated with sign ‘ (pluck single). Char differ with String, because String not such a primitive data type, but have represented a object. type of Char follow order Unicode, so that can use code / u is then followed number from 0 until 65535, but which commonly use is number of hexadecimal from 0000 until FFFF.

    • Boolean

In Java recognized by data type of Boolean which consist of two value just, that is and true of false. Boolean of vital importance in evaluating an condition and is often used to determine program path.

2. Type Data Reference

Excess of programming orient object is can define new data type which represent object of certain class. this Data type is used for the reference of or object of class certain, like String.

  1. Variable

Variable represent container used for save an value at a program with certain type. To define variable, we earn to use identifier to name the variable.

1. Identifier

Identifier is character corps able to be used to naming variable, method, class, interface, and package. As language of program in general, Java have regulation for valid or valid identifier. Identifier can be referred as valid or valid if early with :

    • Letter / alphabet
    • Currency character
    • Underscore (_)

Identifier can consist of :

    • Letter / alphabet
    • Number
    • Underscore (_)

Identifier may not contain @, space or early with number. Besides, identifier may not use or keyword of words owning meaning or used in programming of Java. Lists keyword java :

    • Abstract
    • Double
    • Int
    • strictfp
    • Boolean
    • Flse
    • Static
    • super
    • break
    • fxtends
    • long
    • switch
    • byte
    • final
    • native
    • synchronized
    • case
    • finally
    • new
    • this
    • catch
    • float
    • package
    • throw
    • char
    • for
    • private
    • throws
    • class
    • goto
    • protected
    • transient
    • const
    • if
    • public
    • try
    • continue
    • implements
    • return
    • void
    • default
    • import
    • short
    • volatile
    • do
    • instanceof
    • interface
    • while

Besides using ordinary character, we also can use Unicode as identifier.

2. Declaration Variable

Elementary Syntax :

[data type] [name of variable]

After variable declaration with data type, hereinafter assigning value the variable with sign =. Earn also declaration and assign value in a line. We earn to make variable become constant which cannot be altered by its value by enhancing keyword before data type of variable. So that this constant can be accessed by other class without having to making object beforehand, hence we earn to enhance modifier and public of keyword static.


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Array


Array is a group of variable owning is same data type and expressed by the name of is same. Array represent important concept in programming, because conducive array for the save of reference and also data object in number many and made an index to. Array use integer index to determining its elements sequence, where first element of him started from index 0, both element owning index 1, and so on.



  1. Declaration Variable Array

Declaration Variable array with wanted data type by which much the same to with ordinary variable.

  1. Define Array

After array declaration, we need to define array, in meaning determine bigly of wanted array.

  1. Array Two Dimension

At Java also provide facility to make array two dimension able to assist in programming if array one dimension fall short in yielding an solution. Array two dimension in fact is containing array of array.

  1. Array of Multidimensional

Besides array one array and dimension two dimension, earn also make array of multidimensional at Java. Array of Multidimensional represent array which consist of array which do not limited to two just dimension.


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Exception


We know that no perfect program, and no consumer program which also perfect. Therefore, needed by an mechanism which assisting to handle mistake or error that happened, making moment goodness and also program implementation. Java provide mechanism in programming to handling the things is so-called with exception. Exception is event that happened when program meet mistake at program instruction moment run. Many matter able to generate this event, for example crash, damage hard disk out of a clear sky, so that programs do not can access certain files. Programmer even also can generate this event, for example by conducting the division of with number zero, or admission filling of element array exceed the amount of array element which is allocation etcetera. Exception consist of two kinds of group, that is :



  • Exception representing runtime exception subclass

  • Exception which non runtime exception subclass.

Runtime exception usually because of mistake of program or at design program. For example Null pointer exception which because of process of initializes imperfect program and Array index out of bounds exception caused to access array exceeding existing array capacities. In language of Java, on the happening of mistake, automatic will be thrown a object of is so-called exception, what then can be processed furthermore by readily functions handle the mistake. Process throwing of exception the is often recognized with term of throwing exception, while process acceptance of exception which is pertinent to be recognized with term of catch exception.

    1. Block of Try – Catch

For the handling of exception, in Java used by block of try and of catch. Block try used to place program codes of Java pregnant of code program which possible throw exception. block of Catch used to placing program codes of Java used to handle a certain exception. After us enhance block of try – catch to overcome error that happened, hence program will present message of error that there is error that happened at console.

    1. Object of Exception

Object of Exception yielded to earn we exploit to know furthermore regarding or error of exception that happened. Exception represent subclass of throw able class defining some method which also inherit by exception. Three important method is :

  • getMessage()

This Method return content order to depict exception happened.

  • printStackTrace()

This Method present message of and error of stack trace to standard of error output stream which usually represent console of windows if program representing console programs.

  • printStackTrace(PrintStream s)

This Method present message of error to object of print stream taken as parameter. If wishing to present message to console, we earn using System.Out as parameter.

    1. Block of Try – Catch – Finally

Besides try – catch, we earn to define block of try – and catch of finally which owning more complete process, because at finally we earn to define program code which is always executed, goodness there is exception that happened and also if do not happened exception is at all.

    1. Make New Class Exception

We earn to make new class which inherit exception class of java.lang.Exception. Anytime we need to define exception class which more specific for is certain, so that handling of exception earn more goodness.


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Thread


Thread represent ability provided by Java to make Taft application, because thread in program have duty and function separate. With existence of thread, can make more efficient program in speed matter and also usage of resource, because we earn to divide process in our application at the same time. Thread is generally used for the programming of multitasking, networking, entangling accessing to source energy by concurrent.

There is two way of which can be used in making a thread, that is :



  • Making subclass of thread

To run thread, can be conducted by calling method start(). moment of Start() run, hence in fact run method() of class will be run. Become to make thread, have to define run method() at definition of class.

  • implementation of Interface Runnable

Way of this represent the way of simplest in making thread. Runnable represent abstraction unit, that is class which is implementation this interface only enough function implementation of run(). In function implementation of run(), we will define instruction which developing a thread.

    1. Daemon And of User Thread

There is two Kinds of thread in Java, that is and daemon of user thread. Daemon thread represent thread which is its life cycle depend on especial thread or mains, so that if mains thread end, hence automatically daemon thread-thread also follow to end. While thread user measure up to differ, where if especial thread have, hence thread user will continue to be run.

    1. Sleep

Arranging thread to discontinue its process a moment and give opportunity at other process or thread.

    1. Interrupt

If wishing an thread to discontinue process, hence require to call interrupt method. Interrupt used to give signal at thread to discontinue its process.

    1. Synchronized

Synchronization is block or method owning addition of keyword synchronized, so that if run hence only one thread at one time which can run program block or method. Other Thread will await thread which is executing this method till finish. Synchronization mechanism important in the event of division of data and also resource among thread-thread. Synchronization also lock at data or resource which is processing.


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Tips Make Professional Website


  1. Homepage (especial page) sites you have to earn to be accessed maximal 8 second or can be accessed to pass network connection minimum Internet 28,8 kbps. If process of connection requiring very old time, this matter of have potency loss of customer which do not “forbear staying” awaiting too old. Finally sites we will not visit to process all “candidate of customer”.



  2. Ascertaining to figure in META Tag at each page your website. META Tag is conducive code engine search (searcher machine like : Google) to determining relevant keyword of your website.

  3. Choose background color (appropriate background), don't use color influencing text to be read color of sites become a your liver expression. Color of Orange symbolizing fun while purple or is black symbolizing bleakness. For that choose appropriate color for your sites pursuant to content which implied in the sites.

  4. Use animation need, don't too abundant because can influence consumer concentration when is being information. Besides, animation also can pursue access to page of your sites. A good animation non becoming guarantee that your sites draw attention visitor.

  5. Especial page of sites have to be more be specific so that all visitor can know product which on the market. For example, if your sites represent a consultancy institute hence consulting services which better is on the market presented by in especial page. Visitor don't feel to confuse with existence of your ill defined sites of product which on the market.

  6. Avoid installation of advertisement (banner) on the top your website. Limit the amount of banner to be displayed, maximal 2 and ideally enough 1 banner. More and more amount of banner, longer process to access and will very is bothering consumer concentration when visiting your sites.

  7. Check wrong spelling and ascertain and picture of link in circuit better before presented on-lonely. Mistake in typing address of url result the page of “ ERROR”. If a sites there are one of the or some page which is error make the sites the look do not professional.

  8. Equip your website with knob of navigation easy and lapped over elegantly at tabletop, under is, left, and also right. If using knob in the form of picture, important to remember that possibility of process access more long time. Why? Because picture have size measure which enough is big, and as we know. A page of sites maximal fairish at the most 100kb.

  9. If cannot help use Frame, use precisely. Basically, usage of Frame in a sites will impress do not professional. Avoid page which needing “scroll”, this result less visitors balmy to look for information so that will in short order is “blurry” of your sites.

  10. Reckoning the amount of click required to move from page one to is other. If too much click will very dragging on to visitor. You can apply system balmier navigation by figuring in logo at every its page.

  11. If using “JAVA” at your website use precisely. Offering “Java” or “No Java” to visitor because can influence each performance of browser. Avoiding the existence of advertisement “up pop” to make visitor becoming to tire of.

  12. Don’t enhance “auto play” voice when someone visiting your sites. Better offer, do using intro along with audio (sound) or direct to especial page.

  13. Check your website with a few type of browser because each browser have different ability.


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Format Graphical


Graphic / picture in a website can give visual effect remarkable to website, but can add time of connection effect of to the number of presented picture. Graph in website can in the form of static, animation, and photography. So that connection to our quicker website, require to comprehend some file format which is often used by at a website, among others :



  • GIF : owning color 8-bit, supporting in the form of is transparent, color area compress by solid, reducing the amount of color and braid for the process of download quickly, also can be used to 7 to making animation in the form of graph (graphic animated).

  • JPG : owning color 24-bit, handling of quality and brightness hue which is found in a photo, can be kept in high format with quality and also rend an (low or high resolution), a file of jpg earn is also used by version low resolution (resolution low) of picture which look when picture is, do not support transparency.

  • PNG : PNG-8 support color 8 beet, area compress condensed color, taking care of durability detail, supporting transparency, compression more is sophisticated compared to gif because compress can around 10-30% smaller than format of GIF.


www ( Word Wide Web : representing corps of web server of functioning whole world provide information and data to be used together.

Web is facility of hypertext capable to present data in the form of text, picture, voice, animation, and other multimedia, where among the data each other related / relevant and correlate one with is other. To facilitate in reading the data needed by a browser web like Internet Explorer, Netscape, Opera, and also Mozilla Firefox.

Website (web sites : representing data repository and information pursuant to certain topic. Supposed by of this site web like containing book of certain topic.

Web Pages (page of web : representing a special page 2 from certain web sites. Supposed by of page of web this like special page of the book.

Homepage : representing containing page wrapper of table of contents or menu from a web sites.


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Multicast


Multicast is one of the result of idea of innovative able to assisting many in make-up of service of communications especially in the case of network of Network. In this handing out will a little a few to regarding Multicast this, where which in a word also he represent alliance from nature of had by communications of Unicast and communications of Broadcast. Excess and risk communications of Multicast this earn us know from comparisons which we conduct with methods other communications, where which later lacking of from communications of Multicast this represent new challenge is we which must overcome in the future.



Multicast IP represent IP datagram as within reason other datagram. the differentiating of it is, field of destination address at IP multicast datagram will contain wrongly one IP address which including class of multicast address. By using multicast address as address of is target of, we earn to conduct address at a group of host at the same time with only delivering one just datagram. In this handing out will study bases communications of multipoint, address multicast, needed to extension and condition is delivery and acceptance of multicast datagram, network design of multicast and various aspect which relate to network of multicast like routing multicast.

Traditional application at network of TCP / IP generally only entangling communications between two host. In its growth of consumer of network start to feel requirement to conducting communications entangling more than two side concurrently. some application at computer network start to require communications of multipoint, among others application of chat with, video and audio of broadcast to make radio broadcast and of TV at computer network, and also video application of conference having the character of multimedia, and real-time of interactive.

If evaluated from way of acceptance of datagram by host at network of TCP / IP, there is some ways able to be gone through for the designing of network application having the character of multipoint that is :

1 Unicast

Very classic Point-To-Point communication use IP datagram with mode unicast. At mode of unicast each every datagram have address of is target of unique (property of host certain). communications of Multipoint can be realized by making some relation at the same time at some host, what is each delivering unicast datagram. Coat application will deliver one coffee to each every host becoming communications member this multipoint. This technique very simple for implementation, because its principle only pursuant to ability of multitasking from an host to serve various application from some host at the same time.

But that way the way of this have limitation, especially if amount of host in concerned in communications of multipoint this plenty. Corresponding Host of multipoint have to make communications relation counted host in concerned. Besides improving work load each host in concerned, traffic generated by this communications will be collapsible duplicate counted host in concerned. This matter will generate the problem of usage of Bandwidth. Paying attention picture 1 for this illustration :



















Picture 1 Replication datagram by host in mode of unicast.

From picture, seen that host of is source of performing a relation with A host, host B, Host C (third of located him in network which is equal to host of is source of, namely network 1) and D host (lay in network 2). In this case application the run is application multimedia (video, audio, and conference text), where host of is source of sending information which is same to entire / all host related to him. At host of is source of, happened replication datagram counted amount of host performing a relation with him. Important to remember that content each every this is same datagram precisely only differing just target address (at field of destination address).

Several things able to highlight from mode scenario of multi-unicast this is :

  • This technique is the way of simplest, because do not need changes at network side or module of IP in each host.
  • For the communications of point-to-multipoint, work load of host source will mount proportionally with amount of host related to him.
  • Usage of bandwidth by source host will mount because source host have to deliver is same information counted amount of host related to him, although the hosts reside in at one media shared like Ethernet. In example in of, host of is source of using bandwidth equal to 4 times needed to bandwidth delivering information to an host.

Let us see how the land lies if there are 30 host related to host of is source of. If to deliver peripatetic picture or video live with quality is needing bandwidth equal to 100 kbps, hence generated by bandwidth aggregate is host of is source of to serving 30 host become equal to 3 Mbps. conceiving also if half (15) is host exist in network 2, while network 1 and 2 attributed to channel of WAN which enough quickly like T1 (1,54 Mbps . pertained Channel is the speed high direct collapse effect of traffic which is very mount is the. From breakdown of above, we earn concluding weakness of this method namely :

  • work load of Host will mount.
  • very big Bandwidth need for the communications of multi-point entangling amount big host.

While advantage of this method is to :

  • Representing simplest design for implementation.
  • Do not give burden at host which not such a target of datagram.

2 Broadcast

Way of other to submit is same information to entire host is with method of broadcast. Conception Broadcast at computer network (Specially at network layer in protocol family of TCP / IP) and have been explained by at previous chapter. To delivering information to entire/all host exist in is same network, host enough delivering one addressed datagram to pertinent network address broadcast. Because entire / all host which is on one network have is same address broadcast, hence entire / all host will accept the datagram mentioned as information which must be accepted. Paying attention picture 2 for the illustration of this broadcast :











Picture 2 Delivery of datagram to address broadcast.

In this way, bandwidth generated by video relation of conference in an network do not base on the amount of host in concerned. And so it is with burden of host consignor, because only enough send one datagram able to be accepted by all host at network. However, host which do not want to belong at video of conference this also accept the datagram, because using is same broadcast. This matter will add activity of host which keep off because have to process the datagram before is finally disregarded. Besides, each every network have address broadcast which different each other. If this datagram is continued by router to each every address broadcast of network which in circuit with him, hence mentioned datagram can will spread over to various network which do not wish to accept the datagram.

3 Multicast

Way of third to make communications of multipoint is by joining both excellence is way of above in the case of delivery of datagram, namely :

  • Delivery only delivering one datagram to reach entire / all host representing member of group
  • Datagram only accepted by a number of referred as by certain host of group host.

Way of this referred as by mode of multicast, namely by mentioning one address multicast as address destination of sent datagram. As which have been explained, address multicast do not wear for address an host, is but addressed to address a number of host merging into one group running is same application. Paying attention picture 3 as illustration in delivery of datagram at communications of multipoint.
















Picture 3 Delivery of datagram to an address multicast

At picture above, a number of host conduct communications of multipoint to run an application with. Host in concerned in communications of multipoint this some of is on network 1, some of again at network2. Between network 1 and network 2 connected to through router. One of the host (at picture referred as by host source) delivering datagram to an address multicast (taking example 224.22.33.44). To be more facilitate, this address multicast we is Identification with group 1, caused by possibility of usage of other address multicast as group 2, group 3 , etc. this Host Source only delivering 1 datagram to network. At network 1 using media shared, entire / all host in fact hear this datagram. Special to hosts in concerned and express itself as group 1 (owning address multicast 224.22.33.44 , datagram will be processed furthermore by coat in of IP, whereas to host which keep off (host C), datagram will be disregarded as other datagram which have address of is target of not to it.

At network 1 using media shared, entire / all host in fact hear this datagram. Special to host-host in concerned and express itself as group 1 (owning address multicast 224.22.33.44, datagram will be processed furthermore by coat in of IP, whereas to host which keep off (host C), datagram will be disregarded as other datagram which have address of is target of not to it. Constructively router which have owned ability of multicast, this datagram is distribute to network 2 caused by member of group 1 which reside in at network 2 any is amount of host at network 2 this. Decision to continue or do not continue multicast datagram to other network arranged in an protocol mechanism. With this protocol, multicast router can know at particular network there are member

an group. Its conclusion, usage of mode of multicast in form of communication of multipoint this have excellence some that is :

  • work load of Host light consignor enough, because needn't conduct datagram replication.
  • requirement of bandwidth for the transition of datagram do not base on the amount of host which involve. One or one hundred host in concerned at one network, bandwidth which is need being equal. And so do if at network 2 there are tens of host as member of group, router only require to continue one datagram, just to reach entire / all host.

While weakness (can be read as consequence) this method is to :

  • Needing new standard at protocol of IP and data protocol of link layer (for example Ethernet) to be able to send and accept multicast datagram.
  • Needing new protocol mechanism to arrange allocation of multicast address as certain group, membership of host at one particular group in an network, datagram routing multicast, etc.


By : Willy Wahyudi


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Socket


In communications between network required a interface between program connective application of communications some protocol ( program applications interface, API). In this case API represent interface which look to all programmer. In consequence, used API types very depend on system language and operation of programming used. API to be studied to work for network in system operate for UNIX by using language of programming C. In fact for the scope of this is there are more than one API type, but to be included here is Barkeley Socket Interface. To the transfer of having the character of connection-oriented process that happened is : first time server put into effect, then followed by client which later; then will conduct connection to server. As for its illustration shall be as follows :

















Socket Address

System Call related to networking at BSD always addressing its, it to a structure of address of socket ( address socket). structure defined in file. header .


System Call Socket

Some elementary call system which used to conduct programming network :

a. socket system call

b. bind system call

c. connect system call

d. listen system call

e. accept system call


Definition Protocol

Server run at port 1500 and listen at port 1500, later then client run for connection to port 1500. After connection formed by client deliver and address place port of listen – its to server. Later then after server accept the information the of client hence server make connection to client pursuant to information port and address of listen client. After connection formed by hence server deliver ack to client and from side of client accept ack delivered by server.

Hereinafter side of client ask and user name of password. After and user name of password, hence client deliver request to server to conduct file upload. Later then server pass in client to the transfer of file. After client accepting the permission hence client the transfer of file to server. Later then after is altogether sent, hence client deliver ack that transfer of file which is the conducting of have.


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