Tuesday, December 23, 2008

Anti-Spam Technologies

Spammers and hackers are constantly shifting strategies and tactics to get around spam filters. As new tactics evolve, anti-spam vendors must layer their new technology on top of the old. The following are the four major types of anti-spam technologies:

Content filtering
Early solutions relied primarily on word lists, email signatures, and lexical analysis. For instance, “Viagra” is a word that’s often tagged by content filters. To adapt, spammers started spelling it with “1”s instead of “I”s, and added spaces. Later, they began to include HTML graphics instead of putting in text. Recently, spammers began to put their content in embedded PDFs; some email security vendors can filter the content of PDFs as well.

Behavioral analysis
This type of anti-spam technology used Bayesian analysis, statistical analysis and heuristics in order to predict spam. The onus for this type of technology often fell on administrators, who had to do extensive tuning and trial and error before getting satisfactory results. Bayesian filters also increased the likelihood of false positives.

Identity analysis
This looks at the identity of known spammers often referred to as “reputation analysis”. This is a promising technology, but may require email authentication to become more widespread. Also, zombie attacks can get around this type of defense.

Pattern detection
By analyzing patterns of traffic, as much as 80% of traffic can be thrown out as invalid. This reduces the load on email servers and downstream email filters. This type of detection also does not add to the rate of false positives. All these technologies can layer on top of one another to create an effective anti-spam filter. However, organizations need to implement a secure messaging solution that takes the encryption burden of the end users and intelligently does the right thing.

Spamming and Dark Traffic

Some anti-spam vendors rely on identity analysisor reputation analysis to block spam coming from certain IP addresses. To get around this, spammers have now implemented zombie attacks or botnets (robot networks), planting spyware or Trojans on unsuspecting machines, which then work as slaves to remote machines, which then carry out a spam campaign.

Instead of one machine sending out tens of thousands of emails from a single IP address, zombie attacks can have a thousand slave PCs and a thousand different IP addresses sending out ten to twenty emails each. Effective email security requires vendors to constantly add adaptive techniques to their anti-spam systems, assuring organizations that even new threats like zombie attacks won’t get through their systems and email security professionals don’t get those angry calls or emails about unwanted messages.

Today’s enterprises expect spam filters to catch at least 95% of spam; the best spam filters catch upwards of 99% of unwanted emails. Even more importantly, however, spam filters should rarely catch a valid, wanted email and throw it out. These “false positives” have caused many arguments between companies when an expected email has been filtered out and never delivered.

Experts recommend that the false positive rate be as close to 0% as possible, since false positives can cost organizations dearly. Spam is not the only threat to email servers. While spam is unwanted and often annoying, a bigger threat to networks today is malicious and invalid email traffic, referred to as Dark Traffic, which can actually damage an email system or a network.

Dark Traffic includes viruses, worms, and Trojan horses that are sometimes attached to otherwise valid-looking emails. The directory harvest attack (dHA) is often a precursor to spam, when a corporate email server is bombarded with thousands or even millions of random name combinations in order to determine valid email addresses.

Email denial of service (doS) attacks, malformed SMTP packets, and invalid recipient addresses are other types of dark Traffic. As mentioned above, spam and dark Traffic can have a huge effect on bandwidth, often representing 70-90% of all inbound email traffic. Stopping spam and dark Traffic is essential to scaling email infrastructure accurately and keeping network performance up.

Tuesday, December 16, 2008

PageRank Vs Alexa

Many websites that have long operated, but zero PageRank with high traffic Alexa. To get the Google PageRank is not easy because the measurement using the algorithm to consider "more than 500 million variables and 2 million term" (Google source).

PageRank related with many numbers link your site to other link, where the page always appear on the top search engines and needed the right keywords with relevant contents. PageRank not real traffic like Alexa ranking but PageRank only algorithm how important the page for everyone.

Alexa ranking is real traffic, where to improve alexa ranking can use other services that provide traffic, such as directory website, buy traffic on google adwords or others service. Higher Alexa traffic does not a website the index by google. So, PageRank and Alexa both very important as indicator the website needed lot of user anytime, anywhere and get it as soon as possible. Good luck.

More about PageRank : Wikipedia

Tuesday, December 9, 2008

Choose a Laptop Computer

LaptopComputers are a tool that is very important for those who use a computer every day as tools to complete the work done, such as data processing. With the progress of technology, this form of a computer when a smaller, more lightweight (laptop) and can taken you like.

This laptop easy to use and can run many applications such as Like desktop computer. Applications that can run the video, spreedsheet, music, VoIP and so forth. Computer technology is a very rapid development. Many products are offered with prices that vary.

Consideration depending on the price of some of the existing specifications such as processor, big hard drives, RAM, and a computer model, VGA and so forth. To choose a laptop computer you should note the specifications are offered, whether in accordance with the application that you will use.

In choosing a laptop computer also needs to be: Is the laptop computer can be upgraded in the day to improve the performance and the size of the cache memory that serves to accelerate the process of read / write. Before you buy a laptop computer you should find plenty of information so that one does not choose when to buy your dream laptop.

Friday, December 5, 2008

Check IP Address

Many gadgets that we can use to display or know the IP address, Hostname, city, region, time and country. One of the gadget can be used is the google gadgets.

Data shown on this gadget is the IP address of the data that you connect with the Internet network and you can also check the IP address of other locations around the world.

If you use a home router to connect to the Internet is usually the IP address will be shown is the address of the router or your proxy and your IP address (the IP public) will always change every login to the network or get a new IP address each session.

Saturday, November 22, 2008

Definitions Of Programmable Logic Controller (PLC)

Programmable Logic ControllersProgrammable Logic Controllers (PLC) is a computer that is easy to use electronic or user-friendly control functions that have for various types and levels of difficulty diverse. Definition Programmable Logic Controller is electronic systems that operate digital and designed for use in the environmental industry, which uses a memory system that can be programmed for storage in the internal instructions that implement specific functions such as logic, sequence, time, counter and operating aritmatik to control the engine or through the process modules I / O digital and analog.

Based on the concept of PLC name is as follows:

Show ability in terms of memory to store programs that have been made that easily changed the function or usefulness.

Shows the ability to process the input in the aritmatik and Logic (ALU), which is conducting operations compare, enumerate, multiply, divide, reduce, inverter, AND, OR, and others.

Shows the ability to control and manage processes that produce the desired output

PLC is designed to replace a series of relay sequensial in a control system. In addition can be programmed, the tool can also be managed and operated by people who do not have the knowledge in the field of operation of the computer specifically. PLC has a programming language that is easily understood and can be operated when the program was created by using the software in accordance with the type of PLC used is entered.

This instrument works based on inputs that are depending on the circumstances and at a certain time then that will or ON-OFF-I output-output. '1' shows that the situation is expected to be met while the '0' situation is not expected to be met. PLC can also be applied to the control system that has a lot of output.

PLC Functions

A. In general
PLC function and usefulness in practice PLC can be divided in general and specifically. PLC functions are as follows:

Control sequence
PLC to process the input signal into a binary output that is used for the purpose of processing techniques sequentially, in order to maintain the PLC step in the right sequence of the process.

Monitoring Plant
PLC continually monitors the status of a system (such as temperature, pressure, high altitude) and take the necessary action in connection with a controlled process (for example, the value has exceeded the limit) or display a message on the service.

B. Special functions
PLC to provide input to the CNC (Computerized Numerical Control). Some PLC can provide input to the CNC to the interests of further processing. CNC when compared with the PLC has a higher accuracy and more expensive. CNC is usually used for the finishing process, establish working object, technology molding and so forth.

CNCThe working principles of a PLC is to receive input signals a process manageable, then do a series of instructions to the logic input signals in accordance with a program stored in memory and generate output signals to control the Actuator or other equipment.

Voice Over Internet Protocol

VoIPVoice over Internet Protocol (VoIP), or with other Internet names Telephony is associated with the transmission of voice, is a technology for transmission of data including the usual form of data, voice or video in real time through the Internet (IP channel). In the transmission of voice applications, VoIP is strong candidate to replace the conventional phone network using the PBX (private branch exchange). This is because the cost is cheaper, especially for long-distance connection. Moreover, now said that the quality of the VoIP service can exceed the quality of network services conventional. In the process adoption, various obstacles appear, especially for telecommunications technology company in such a way so that difficult to 'upgrade ' networks.

VoIP Interfaces

VoIP using standard ITU (International Telecommunication Union) H.323 standard for communication. H.323 standard consists of components, protocol, and procedures that provide multimedia communication via packet-based network. The form of packet-based network that can be passed between other Internet network, Internet Packet Exchange (IPX)-based, Local Area Network (LAN) and Wide Area Network (WAN). H.323 can be used for multimedia services such as voice communication (IP telephony), video with voice communication (video telephony), and combined voice, video and data.

Design and development goal is to enable H.323 interoperability with other types of multimedia terminals. With a standard terminal H.323 can communicate with H.320 terminals on the N-ISDN, H.321 terminals on the ATM, and H.324 terminal switched on the Public Telephone Network (PSTN). Terminal H.323 real-time communication allows two-way form of voice, video and data. H.323 standard consists of 4 components of physical I used when connecting communication multimedia point-to-point and point-to-multipoint on some kind of network:

VoIP NetworksTerminal
multimedia communications for the real-time two-way. Terminal H.323 can be a personal computer (PC) or other means of self that can run multimedia applications.

Used to connect two different networks, namely between H.323 network and a network of non H.323, for example, the gateway can connect and provide communication between the terminals with H.233 phone network, for example: PSTN. In the form of a network connecting the two different done with the protocols for call setup and release and send information between networks connected to the gateway. However gateway is not needed for communication between the two terminals of H.323.

Can be considered as a brain on the network because H.323 is a point important in the H.323 network.

Used to service the terminal H.323 conference three or more. All terminal who want to participate in the conference can build relationships MCU with the materials for the conference, negotiations between terminals to ensure the audio or video coder / decoder (codec). According to the H.32 standard, a MCU consists of a Multipoint Controller (MC) and several Multipoint Processor (MP). MC Negotiations handle H.245 (concerning signaling) between the terminals to determine the ability audio and video processing. MC also to control and determine the series audio and video will be multicast. MC does not face directly the media. This task was given to the MPs who make Mix, switches, and process audio, video, or bits - bits of data. Gatekeeper, gateway, MCU and the logic is a separate component in the standard H.323 but it can be implemented as a means of a physical.

How To Access The VoIP

VoIP adapterTo access the necessary VoIP Terminal Adapter or SoftPhone. SoftPhone is a software-based VoIP terminals such as Netmeeting. For it is necessary Soundcard computer equipped with a headphone and microphone following. Connection to The Internet can use a dial-up modem or xDSL. theoretically modem 14.4 kbps is sufficient for the learner-VoIP.

However, DSL Flatrate better for VoIP. Neither because the higher the speed, but the connections of 24 hours. So that VoIP normal telephone functions such as: contact and can be contacted at any time. To This actually needs more appropriate when used TA (Terminal Adapter).

TA is a from of the small aircraft that can be connected to a VoIP network without using the computer. So the computer does not have to light only for 24 hours standby waiting for incoming phone calls. In addition to electricity also noisy. You can connecting ordinary telephones (including wireless telephones) to the TA, so that you there is no need to use headphones or a microphone. With VoIP TA really feels like a normal telephone.

Sunday, November 16, 2008

Offshore Communication With WiMAX

WiMAX network low-cost than the network such as 3G. Oil and gas producers can use WiMAX equipment to provide communication links from land-based facilities to oilrigs and platforms, much to support operations, security, and basic communication and easy for the degree. Monitoring remote monitoring of the site, and access databases. For example, a video clip from one component or subassemblies can be sent to land-based team of experts for analysis. Including the security alarm monitoring and supervision of the video. Basics include voice communication telephony, email, Internet access and video conferencing. The network can be set or redeployed in a matter of hours, minutes, if not, even when oilrigs and platforms that moved to another location.

Offshore Wimax
Cable solutions are not appropriate for this scenario, because the facilities offshore, and since oilrigs are moved regularly and are in the field of oil or gas. Communication to monitor the status of the assets can be maintained, using battery-supported WiMAX terminals. Communication with WiMAX networks have a large bandwidth and multiple modulation used in accordance with the distance including BPSK,QPSK,16-QAM and 64-QAM. When equipped with a high-power amplifier and operating with a low-level modulation namely BPSK or QPSK.

Saturday, November 15, 2008

Optimization WAN

Increased productivity means that the user need quick access to applications, which usually require a local server to the user. But that's contrary to the regulations, which will recommend to centralized servers to facilitate the reputation and backup data center. WAN applications, which tend to be slow because that is not able to understand the application and WAN performance. No help more and more content-rich in the WAN.

The performance of low priority because the applications to compete with the critical resources for WAN applications. In addition, the lack of manageability occurred because of how the application and make a WAN can not be seen. Key from the WAN Optimization is the compression and caching, acceleration, application visibility and control. Each region cut costs and increase productivity.

They also improve access to share resources, enhance recovery, enable the roll-out new applications, reducing the time to problem-shoot, much the spread of automation devices and, ultimately, manage the site without local staff. In addition to this, users improve productivity, save money applications such as VoIP enabled applications and can get a critical priority.

Compression and caching sequence needs to be done because the organization running the application with the traffic of different characteristics, needs a combination of a decrease in IT equipment to improve WAN caching capacity. In order operate on shared data in the file structure of the web page, so that they can even eliminate repetition in the modified files.

If a WAN pipe is not full, but users continue to complain about the performance of applications, the opportunity that latency is a mistake. Latency can affect the application layer on a different sometimes it's the behavior of the TCP slow applications, such as FTP and transfer applications, and sometimes the application Layer protocol. Accelerating TCP will do anything to expedite the application because they send data in small and even smaller than the TCP how, so that the open TCP window size does not help them until they are accelerated in Layer 7.

Then, TCP acceleration can also kick in to expedite the application. WAN optimization and acceleration technology designed to improve the performance of applications and to improve the user experience without having to increase bandwidth or reduce latency.

Tuesday, November 11, 2008

Online Fraud Protection

When this happens a lot of online fraud action. Symantec's program Online Fraud Protection. This program is designed to protect businesses that make the volume of financial transactions to avoid large losses from online fraud is now available, including phishing and pharming. Online fraud is a significant problem faced by all organizations that do business online. Symantec's latest report is Internet security threats, volume XIII released in April 2008 that indicates that the threat of online fraud against companies and consumer organizations.

In the last six months of 2007, Symantec observed more than 85,000 phishing hosts. Fraud attacks become more sophisticated and increasingly targeting business customers and devastating. Organization generally less effective to overcome online fraud. Symantec's Global Intelligence Network also Provide a comprehensive view of Internet attacks. Security intelligence activities is based on data collected from in the world. Symantec's Global Intelligence Network that analyzes data from more than 2 million email accounts, 120 million system and over 40,000 devices in more than 200 countries.

Online fraud protection include:
Phishing monitoring:
Phishing attacks on the client's brand. Transaction monitoring: Review on the back-end transaction systems and blocks fraudulent activities.
Online Fraud countermeasures:
To respond quickly to the attack to minimize losses and protect the reputation of the brand
working with ISPs to reduce the activities of fraudsters.
Malware Intelligence and Analysis:
Provides monitoring of malware targeting specific and the brand new malware analysis behavior.
Education and Consumer Protection:
Help organizations educate and protect their customers from online enduser
threats and minimize risk fraud.

From the above data should protect ourselves from online fraud to minimize the losses that will occur. Many antivirus software that can protect you, so do not wait, especially before they occur.

Monday, November 10, 2008

Routing Data Packet Using Tracert

When we send messages or retrieve data on the specific address, we need to know the data message is sent or received via any route. This need to know how long the data is our message to the objective of hops and any data transmitted. By using the tracert Instructions, hops into the package can be seen and known time that data.

This below example result routing from my computer:
traceroute to yahoo.com (, 30 hops max,
40 byte packets
1 vlan250.lon-service6.Melbourne.telstra.net (
0.264 ms 0.267 ms 0.294 ms
2 TenGigabitEthernet0-12-0-2.exi-core1.Melbourne.telstra.net
( 0.604 ms 0.436 ms 0.411 ms
3 Bundle-POS1.chw-core2.Sydney.telstra.net (
14.732 ms 14.772 ms 14.777 ms
4 Bundle-Ether1.oxf-gw2.Sydney.telstra.net (
14.897 ms 14.926 ms 14.931 ms
5 TenGigabitEthernetx-0.syd-core04.Sydney.reach.com
( 15.287 ms 15.238 ms 15.362 ms
6 static.net.reach.com ( 162.323 ms
162.181 ms 162.201 ms
7 static.net.reach.com ( 162.324 ms
162.535 ms 162.361 ms
8 yahoo.paix05.net.reach.com ( 195.028 ms
194.956 ms 194.941 ms
9 ae0-p141.msr1.sp1.yahoo.com ( 195.051 ms
ae1-p151.msr2.sp1.yahoo.com ( 195.011 ms
ae0-p141.msr1.sp1.yahoo.com ( 195.075 ms
10 te-9-1.bas-a1.sp1.yahoo.com ( 195.217
ms te-8-1.bas-a1.sp1.yahoo.com ( 195.377
ms te-9-1.bas-a1.sp1.yahoo.com ( 195.211 ms
11 * * *

You can using instructions: C> tracert domain ->
example tracert my blog C>tracert adrianindo.blogspot.com
or using here

International Paid Surveys

MindField Online
Can follow the money with the survey program. MindField Online is the solution to get additional cash income. You can work from home, office or anywhere you have access to the Internet. You need to do is participate in a variety of interesting opinions from the research survey. You get cash for each survey you complete.

SurveySavvy™ online community
This online survey that will provide incentives of 20% of the online community. Incentives are given when you're finished with the survey complete. This online survey will provide an additional incentives when you refer to your friends or your family.

Sunday, November 9, 2008

Increase Your Traffic With Buy Blog

Get traffic and increase your blog or website. With the program, which provides a place to link your blog or website. This can be done with the blog to buy your product reviews.

You choose to live blog or website that complies with the requirements of existing prepare. Terms of which you can select is the ranking of blogs and the budget offered. To buy a blog for the review of the product or increase the traffic, please visit here

PPC And Post Program

To get the money is not difficult if done properly and willpower to move forward. This program is having an option some pay-per-post where you paid with a post that you do, and besides, there are programs paid per click / PPC.

PPC program will pay you to do when visitors click on ads that are displayed and a link will appear automatically on the content of each post if you accordance with the keyword ads. To follow this program please visit here

Set Your Price. Choose your Advertisers. Sign up for SocialSpark!

Making Money With Your POST

Many ways to get monthly income and you can make money with your blog. There are several programs that you can follow to obtain money, with which you post on the blog. Many large companies or advertiser will be pay to send post on your blog.

Connect With Advertisers - Sign up for SocialSpark!

To follow the program paid per post this, your blog must meet the requirements specified by the owner of the program review. Money obtained in accordance with the many visitors who come to your blog. Traffic your blog is very important because this is an important requirement in the program this. For to try this program, please visit to Buy Reviews

Friday, November 7, 2008

Money From Selling Products

Affiliate program is a joint program offered by the owners of the product to a person or company to sell their products. To participate follow these affiliate programs, we are not charged or free. The owner of the product will give cash rewards if we can sell their products.

The more products that we sell so many more of the money given by the owner of the product. When we have become a part of this affiliate program, then we will get the tools that are used to selling products, such as the duplication of the website, content, links, banners.

Example link http://www.example.com/?id=19504, id= 19504 is a seller ID. Affiliate programs continue to progress without any time limit or a lifetime for owners of the products continue to sell products. With this affiliate program we will get a monthly salary when the product sold. Many of the money given to 30% of the price of products sold.

Monday, November 3, 2008

Internet Marketing

Marketing is very important to be done in order to achieve the target to be achieved. Marketing can be done in several ways, namely through email, website, community groups, and forums. Marketing through email is to make delivery of information to the email destination.

Delivery of this email must follow the rules applicable law or the rules that exist, which is aimed at sending someone to do. Delivery of the email that is not the objective will be considered in spamming is prohibited and that is criminal.

So to use email marketing should be done with caution if we are not the domain or email our operations will be terminated by the owner of the service and consequently we can not use email or domain that.

Marketing using the website to make the marketing website, where the website is designed in such a way that reflects the contents of goals will be achieved. Examples of websites that have the money category, the website will contain the content matters related to money.

Similarly, the website has a category of techniques, the site content is the main issues related to technical problems. Marketing with the discussion forums that discuss specific topics, such as cooking forum, forum marketing etc. By using this forum for discussion, target marketing can be achieved if the marketing is done in accordance with the discussion forum.

Monday, October 13, 2008

Highly Eliptical orbit (HEO)

HEO is an orbital satellite that is more than 36.000 Km from the surface bumi. This orbit is the most distant orbital distance from the other. Highly Eliptical orbit was developed by Russia.


Thursday, October 9, 2008

Medical Equipment

Some days I surf, I find affiliate programs in the field of health care equipment sales. Many products are offered with prices that vary.

You can have medical equipment to health or to be sold on the customers. If you want to buy or join as affiliates in this program please sigup. Get discounts and also get a commission of 5% of your sales.

Medical Supplies

Sunday, October 5, 2008

Geostationer Orbit (GEO)

GEOGeostationer orbit is the orbital geo-syncronous that are right on top of the Earth equator (0 ° latitude), with the same orbital with zero. From the surface of the Earth, the objects are in orbit geostationer will appear to be silent (not moving) in space because of orbital objects Period circumnavigate the Earth with the rotation of Earth Period. Orbit is highly desirable by the operator-made satellite operators (including satellite communications and television). Because of the location of the constant latitude 0 °, the location of the satellite only be distinguished by the location of the longitude of Earth.

Geostationer ideas for use in satellite communications published in 1928 by Herman Potočnik. Geostationer orbit popular the first time by science fiction author Arthur C. Clarke in 1945 as a useful orbit for satellite communications. Therefore, the orbit is sometimes referred to as the Clarke orbit. Belt also known Clarke term that indicates the space of 35,786 square kilometers sea level on average above the equator where the orbital geostationer approach can be achieved. Geostationer orbit is very useful because it can cause a satellite processing seems to dwell on one point on the surface of the Earth rotates. As a result, an antenna can point in one direction and keep in touch with the satellite. Satellites orbit with the clockwise rotation of Earth at a height of about 35,786 km (22,240 statute miles) above the surface.

Although the orbital geostasioner can maintain a satellite is still in place on the equator, can cause perturbation orbital satellite slowly move from location geostationer. Perturbation orbital is a phenomenon in which the satellites orbit changed due to one or more external influences such as gravity anomaly distribution of the earth, drag-style interference from the moon, meteor impact or other objects, or solar radiation pressure. Satellites to make do with the correction maneuvers, which are controlled by the station on Earth, this maneuver is known as the maneuvers north-south (North-South Correction) and maneuvers west-east (East-West Correction).

These maneuvers using small rocket-missile (thrusters) to the satellite body and the direction set in accordance with the direction of the correction. This small rocket ignition consumption fuel will be brought from earth satellites as a stock. If the stock is exhausted, then drop the age of satellite operations - because when he deviate from orbit, no longer the way for the operator of the earth for corrections and return it to where it should be.

Monday, September 15, 2008

GeoSyncronous orbit (GSO)

GeoSyncronous orbit is an orbit objects (usually artificial satellite) with the earth as the center, which has the same Period with the rotation of the earth that day or hour 23.9344. The orbital geometry has half the main axis (semi-major axis) length of 42164.17 km. GeoSyncronous with the orbital satellite will be located above a point on the earth at certain hours. Apart from the time the satellite will appear to shift relative to that point. If the satellite GeoSyncronous have the perfect circle of orbit and orbital equator line with the views of the earth, the satellite will appear to be silent, so-called the orbital Geostationer.

GSOIn 1974 satellite weather SMS 1 (Synchronous Meteorological Satellite) satellite was launched as a functioning GeoSyncronous send some pictures to a television station. After several experimental satellite in 1975, it changed into geostasioner orbit.

Friday, September 12, 2008

Medium Earth Orbit (MEO)

Telecommunication services and the demands of the mobile cellular systems and wireless. From here appear discourse satellite Medium Earth orbit (MEO) and LEO [Low Earth Orbit]. Unlike satellite Geo, which sit on the distance of 22,300 miles above the Earth, LEO satellites gather in the distance about 400 miles only, and the MEO orbit 10,000 km distance between the 36.000 Km. Distance lower, need more advanced technology, allows people to communicate across the world with a mobile phone pocket size. Because of LEO and MEO satellites close together, a network coverage is needed to create the equivalent satellite Geo.

MEOThrough the network of satellites that orbit the track orbital, this system is possible to deliver sound quality with a better effect without resonance. but also how, satellite Geo is still better and more suitable for transmission that has a wide spectrum such as television.

Tuesday, September 9, 2008

Low Earth orbit-LEO

Low orbit is an orbit around the Earth between the atmosphere and the Van Allen radiation belt, with a low inclination angle. These limits are not defined exactly, but usually under 1,500 km above the surface of Earth. This orbit is usually located under the intermediate circular orbit (ICO) and far below the geostationary orbit. Orbital lower from here is not stable and will fall quickly because of the atmosphere of friction. A higher orbit from the orbital This is the subject of electronic failure early because of strong radiation and collecting cargo. Orbital inclination angle with a higher usually called a polar orbit. Objects in low Earth orbit to meet

Low Earth orbit-LEOthe gas atmosphere in the thermosphere (about 80-500 km above) or exosphere (approximately 500 km above), depending on the altitude orbit. Most of the flight space probe has been in LEO, including all the various space shuttle and space station mission; one exception is the suborbital test flights as early Mercury Project and the SpaceShipOne flight (which did not achieve the intended LEO), and Project Apollo missions to the Moon (which passes LEO ).

Wednesday, August 20, 2008

Communications Satellites

The basic concept of communications satellites:

o Earth Station
Earth station is the radio communications station that is located on the ground and functions to communication with the space station.

oSatellite Communication
The communication between the satellite earth station through space or through artificial earth satellite passive.

oSatellite Links
It is a point of communication between earth station via a satellite link, and consists of the earth to the satellite (up-link) and a link from the satellite to the earth (down link). Station earth connected to the central switching from the communications network connecting via the link terresterial.

Saturday, August 9, 2008

Modulation Powerline Communication

PLC (Powerline communication) must work with the signal power / low frequency. Because of high frequency radiation can occur from power cable that can disrupt the frequency of others. This is contrary to the provisions of the SNR because of a variety of high interference can occur. The process of achieving a good SNR value of the constraints faced by the emergence of radiation effects power cable. But the problem can be solved with the methods of modulation:

1. Modulation CDM (Code division multiplexing) or spreads spectrum
Signal information can be scattered in a wide frequency range. The level of the signal information is made with very low expectations will not be subject to the noise level is very high in the PLC.

2. Modulation OFDM (Orthogonal Frequency division multiplexing)
Modulation method is quite stable. Modulastion efficiency can reach 5 bits per Hz higher modulation from the other.

Friday, July 25, 2008

PLC (Powerline communication) Applications

The connection to the Internet as a means to distribute data or voice (VoIP) by using the electricity network.

1.High speed digital Internet
Can be reached and to include all the world, quickly and securely through the Internet connection, e-commerce, e-mail, and e-banking.

2. telephony
The phone connection is very strong using the Internet, which provides security and quality of the conversation clear. We can also send and receive messages from the fax machine.

3.Smart Homes
And the use of the remote control in the home via the Internet allows household appliances such as refrigerators, heating systems and other.

4. Security
A system of security in both visual and motion detector can be monitored or to allow the owner or the safety and security.

5.Health Care Service
The monitoring of every person who needs the help of health PLC through an internet connection.

Wednesday, July 9, 2008

Global Positioning System (GPS)

satellite-GPSGPS is the Global Positioning System navigation equipment that is used to determine the position at any time and anywhere by using satellites. Function of the GPS satellites which are always / continuously send or emit code information used to know / identify the location on the earth.

Segments of the GPS:
space segment, user segment, and control segment.

Space segment
Consists of 24 satellites (21 active and 3 as a backup), each of which is the orbit distance with 11,000 miles above the surface of the earth.

User segment
Consists of tools recipient GPS signals from satellites.

Control segment of the earth from the station that serves as a checker to ensure that the GPS satellites to work properly. Examples in everyday life, used to know the search for the presence / position of someone, help in finding the existence of a car on the highway, to know the position of the aircraft, to know the speed of an object, and so forth.

Wednesday, June 25, 2008

Multiple Access of INTELSAT Satellite

 INTELSATSatellite INTELSAT access using the 2 methods, namely TDMA and FDMA. Time Division Multiple Access with Direct Digital Interface (TDMA / DDI), Digital Speech Interpolation (TDMA / DSI) and Digital Speech Interpolation without.

TDMA is the method used to overcome the back-off and also more flexible in sharing between the satellite to the station and channel. With TDMA, the station can be full access to the satellite transponder with a time slot, so there is no intermodulation strengthening can be maximum, and although troughput high number of multiple access.

Method Frequency Division Multiple Access (FDMA) can be used for analog modulation (FM) or digital modulation (PSK). Location frequency used satellite Internet is the C-band and Ku-Band.

Saturday, June 7, 2008

INTELSAT Satellite

INTELSATINTELSAT Satellite was first launched on 28 June 1965, which was placed in geostationary orbit over the Atlantic ocean. Lunch and operated as the orbit Early Phase (LEOP) headquartered in Washington DC. To access the INTELSAT satellite, INTELSAT has the characteristics that vary for each earth station with the station type:

Standard A has a nominal G / T 35.0 dB / K and the operating frequency band at 6 / 4 GHz for international service.

Standard B has a nominal G / T 31.7 dB / K and the operating frequency band at 6 / 4 GHz for international service.

Standard C has a nominal G / T 37.0 dB / K and frequency bands operating in the 14/11 or 14/12 GHz GHz for international service.

Standard E, the Standard E-1 has a nominal G / T 25.0 dB / K, Standard E-2 has a nominal G / T 29.0 dB / K, Standard E-3 has a nominal G / T 34.0 dB / K and the operating frequency band at 14 / 11 GHz or 14/12 GHz for services to Intelsat Business Services (IBS), Intermediate Data Rates (IDR) international, Internet Trunking Service (ITS) and VSAT. using Turbo coding with QPSK / OQPSK (Standard E-1).

Standard F, Standard M-1 has a nominal G / T 22.7 dB / K, Standard F-2 has a nominal G / T 27.0 dB / K, Standard M-3 has a nominal G / T 29.0 dB / K and the operating frequency in the band 6 / 4 GHz for services to Intelsat Business Services (IBS), Intermediate Data Rates (IDR) international, Internet Trunking Service (ITS) and Turbo coding using VSAT with QPSK / OQPSK (Standard F-1).

Standard G, does not have a specific G / T segment for satellite Internet access services to domestic and international. This standard allows the use of the G modulation techniques and access to other, that is not in the Standard A and M and only the general characteristics of the RF limits.

Standard H, Standard H-2 has a nominal G / T 15.1 dB / K, Standard H-3 has a nominal G / T 18.3 dB / K, Standard H-4 has a nominal G / T 22.1 dB / K and the operating frequency in the band 6 / 4 GHz for services to Intelsat Business Services (IBS), Intelsat DAMA, the Internet Trunking Service (ITS) and Turbo coding using VSAT with QPSK / OQPSK.

Standard K, K-2 Standard has a nominal G / T 19.8 dB / K, K-3 standards have nominal G / T 23.3 dB / K, and in the operating frequency band, 14/11 or 14/12 GHz for services to Intelsat Business Services (IBS), the Internet Trunking Service (ITS) and Turbo coding using VSAT with QPSK / OQPSK.

Monday, May 26, 2008

Increasing Capacity In The System Cellular

There are several ways to increase the capacity of the system cellular.

Using Frequency reuse
Dense population of cells to be overloaded with the relocation frequency of cells that are not overloaded.

Conducting Cell-Splitting
Cells with dense population is doing cell splitting into several new cells into a new cluster of small to add more capacity. This is done by making changes in the parameters of the transmission link budget recalculate and also make a new design for the antenna height of the BTS.
Two types of cell splitting:
• Permanent Splitting: Cell of the permanent, it must be done to the planning cooked to the following matters:
1. The number of channel
2. Power transmitter
3. The frequency allocated
4. Determination of Cell Site
5. Traffic load
• Dynamic Splitting: This technique is also referred to as the "Real-time splitting" because cell division is done only at the time it needed to overcome the traffic density that is temporary
cell splitting
Conducting Sectoring
Dividing cells become sectors, usually 3 sectors (each 120 °) or 6 sectors (each 60 °). Each sector will be served by a directional antenna and the frequency varies. Interesting directional antenna to reduce co-channel, which makes a smaller cluster with a larger capacity.

Tuesday, April 15, 2008

Interference On Radio Waves

Communications that occur in the sellular using radio waves. Radio communication utilizing electromagnetic waves in the transmission of data on the air interface. The data is passed over the interface is not always accepted in the Receiver intact, but the data will have a disability.

Likewise for the transmission of the signal (the conversation) in the water interface will have several obstacles that lead to sound/voice can not be accepted by both.
Constraints in the transmission of signals that there may be caused by:

Decrease the signal strength that occurs depending on the distance between the transmitter and Receiver. So that MS is beyond the reach of the BTS.

Time Alligment
Time used for the transmission of MS signals that are influenced by distance from the BTS to MS.

Rayleigh Fading
Interference signal reception / signal caused by the weak signals received are some signals that the reflection from the nearest object and not a signal that is received directly.

Time Dispersion
Transmission constraints that occur when the digital signal to reach the same Receiver in a different time because there is a rebound occurs that causes a signal not synchronized.

Sunday, April 6, 2008

The Beautiful Fountain

This is a very beautiful place, where we can see the water fountain unique. That all people can see the image directly but through this we can see, although not directly to the place. I may never be able to go to a beautiful place, as far away and required a lot of money to go. Also, some people may have to go to that place for a vacation to enjoy the scenery beautiful fountain.

Trivoli-fountainThis fountain is located in Tivoli

barcelona-fountainThis fountain is located in Barcelona

tivoli-fountainThis fountain is located in Tivoli

Maybe one day I will go see a fountain that is beautiful.

Sunday, March 16, 2008

Wireless Application Protocol

Wireless Application Protocol (WAP) is international open standard for applications that use wireless communication. The main objective to build applications that can access the Internet from the phone handheld or Personal Digital Asistant (PDAs). With the WAP users can use cellular to access the Internet and obtain facilities from each mobile phone.

Opening page site, to view information such as the exchange of information or news, weather, e-mail, even to conduct financial transactions. There are several versions of WAP, among others, WAP 2.0 and 1.2.1. WAP 1.2.1 can only be page displays only simple compared with the WAP 2.0 support language XHTML (extensible hypertext markup language) and image.

WAP in a the first time as a communications protocol that move does not depend on the system certain. WAP is designed as part of the system in the future as well as Bluetooth and GPRS. WAP is a communications protocol that consists of moving several layers and can be run on a different network system.

WAP working with almost the same way the Internet works now. Required WAP gateway to bridge the mobile phone with Internet data and send in receive data. This is the same case with PC users (Personal Computer) that require ISPs (Internet Service Provider) as the gateway to bridge the PC with the Internet. Besides, mobile phone, which is also used to be WAP-enabled, namely is equipped with WAP technology that can be used to access the Internet, mobile phones and card-or SIM cards (Subscriber Identity Module) from operator of cellular telecommunications facilities that provide services to General Packet Radio Services (GPRS)

Saturday, March 8, 2008

Parameters Antenna

antenna parametersParameters of the antenna used to describe a performance antenna. Parameters of the antenna can be related to each other when someone wants to design an antenna, although not all parameters must be considered in depth. Type of antenna parameters include:

1. Radiation Pattern
Radiation pattern is a graphical representation of electricity and magnetic field in the space coordinates. In many cases, the pattern radiation specified in the region and far-field is represented as a function of directional coordinates.
Radiation types:

• Isotropic
Antenna radiation pattern ideal lossless or radiation that direction is the same to all (shaped like a ball). Radiation patterns such as this are usually used as a reference antenna with the unit of measurement dBi.

• Directional
Radiation pattern that is better for a particular direction (for unidirectional and bidirectional one direction to two directions).

• Omnidirectional
The directional radiation pattern, but all the same to the direction (the vertical axis there is no antenna radiation). Radiation pattern is shaped like a sinker. Radiation pattern like this used to broadcast communications.

2. Radiation intensity
Parameters comparison shows that the antenna power by the radiation emanating from an antenna per unit solid angle.

3. Directional
Parameters that indicate the value gain directive on the maximum. In a certain direction, the gain directivity comparison radiation intensity in the direction compared with the intensity radiation antenna references.

4. Gain
Parameters which indicate the ratio of power on the antenna of the antenna with a power reference. Relations between the directivity and gain can be written as follows: G = μD, where the G (Gain), D (Directivity) and μ (the ratio of the intensity of radiation).

5. Antenna efficiency
Consider the efficiency of the antenna total loss that occurs in the input terminals and an antenna inside the structure loss like this can happen because:
• reflection result does not match the transmission channel and antenna.
• Loss conduction and dielectric.

6. Half Power Beam Width (HPBW)
HPBW is the angle between two directions of radiation from half the intensity of the beam maximum value. If converted in dB, the value of HPBW obtained when the power down 3dB.

7. Efficiency beam
This parameter is often used to determine the quality of transmitting and receiving antenna. Efficiency is the ratio of beam power that emanated (received) in the cone angle compared with the power that emanated (accepted) by the antenna.

8. Bandwidth
Bandwidth is the frequency range on both sides of the center frequency (resonance frequency of the dipole antenna), which characteristics of the antenna (impedance input, the radiation pattern, beam width, polarization, the side lobe level, gain, beam direction, the efficiency of radiation) is in the optimal value. Narrow band to this antenna. Meanwhile, for Broadband, the bandwidth is a comparison between the frequency up and down in frequency levels that can be accepted.

9. Polarization
Parameters which indicate that the wave dielectric radiation when the antenna work. When the direction of polarization is not mentioned, polarization in direction is considered the maximum gain. Kind of polarization:

• linear polarization
A wave of Harmonic linear polarization at a point if the electric field (magnetic fields) in the direction of the move in a straight direction all the time.

• circular polarization
A wave of harmonic polarization circle on a point if the electric field (magnetic fields) in the direction of the move in the direction of the coil as a function of time.

• ellipse polarization
A wave of harmonic polarization linear at a point if the electric field (magnetic fields) in the direction of the move formed Locus ellipse in the space coordinates.

10. Impedance Input
This parameter shows the ratio of voltage to the antenna terminal on the flow rate or electric field component of the magnetic fields on a point or value impedance existing antenna on it.

Wednesday, March 5, 2008

The Definition Antenna

antennaAntenna is a metal device (in the form of a bar or wire) that functions to send and receive radio waves. Antenna is the tool to emit radiation or receive radio waves [IEEE Standard Definition]. Based on two standard definition above, an antenna is a conductor or a conductor group, which is responsible for radiating energy electromagnetic radiation into the air and free to collect (receive) electromagnetic energy from another free air.

Antenna change electrical energy from a transmitter into the system of energy and emit electromagnetic radiation into the air. Conversely, an antenna gathered energy electricity will be distributed to the recipient's system. Free air known as the air interface.

How does the antenna?
Radiation is a disturbance that occurred in the electromagnetic field which propagates out from the source of interference. Interference itself derived from sources that flow changed in that time has accelerated the flow of distribution. An electric current or static electric current that moves with constant speed in the straight channel transmission can not emit radiation.

However, a flow that moves with constant speed can be experienced on the radiation conditions below:
• meet the end of the channel transmission.
• find a channel transmission, which trap.
• transmission lines have shaped curve.
• transmission lines to meet the discontinue.
Meanwhile, a flow that can emit radiation accelerated despite creeping through the transmission lines straight.

Saturday, March 1, 2008

Topology Network Computer

Topology network computer is a physical representation of a computer network. In some workstation computer network that will be installed to connect to other computers by using the transmission media. Therefore topology of the network computer is a physical representation of how a computer network constructions . The topology Linear is the primary computer bus topology, Star topology and Ring topology.

Linear Bus topology
Topology is the most simple topology compared with the other. This topology cable who requires only a relatively short order and wired also very simple. Besides, it is also easy to be developed. This network basically consists of several bus, which was installed in the cable together. Network topology with this damage will occur if the diagnosis difficult. In addition, the bus will bear the full burden when network traffic is very solid.

Bus topology
Star topology
Topology is often called star topology because it has a central hub. From the central hub in the form of concentrator is the server, node, or workstation connected. Contact all the tools to do it with the media transmission cable. Ordering cable also relatively easy to modify. However, this cable system with the necessary relatively higher than topology, the topology of the investment will be more expensive. Also still needed a concentrator as a central hub. One of the losses Star topology is broken when the concentrator, the network will not function properly.

Star topology

Ring topology
Topology is using techniques that shaped ring (ring). So as the circle without end, as the ring properly. With topology workstation and server is connected with a circle (ring) on a media transmission. Use cable in the topology is also relatively short, so will be cheaper. Same as Linear Bus topology, when the network is damaged it will be difficult to diagnose.

Ring topology

Thursday, February 28, 2008

Basic Computer Networks

Computer network in principle is the relationship between several computers that allow the occurrence of communication between the computer. Local computer network (LAN), Wide Area Networks (WAN) that links between countries. Communication can be done in various forms such as file transfer, access and the others.

The functions of the computer network is as follows:

1. Share data.
The data contained on one computer can also be used or processed by other computers. With the network system, it can easily computer that a mutual exchange data with other computers. Examples to copy MP3 files from other computers.

2. Software share.
The program is available on one computer can also be used by other computers. With the share of the software, allows all computers connected in one program.

3. Resources share.
The use of hardware together so that the installation does not require any hardware to each computer unit. For example is the use of the printer, scanner or camera.

Wednesday, February 27, 2008

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