Sunday, October 23, 2011

WAN Network Communications

WAN network
Wide Area Network (WAN) is a network that is used to make the interconnection between local networks that are not physically adjacent to each other, which can be separated physically by city, province, or even across the border geography - across countries and continents. There are several WAN Network Technology now that we can use. In contrast to the LAN network, there are major differences between the two which are located at distances that separate networks are connected. WAN using different transmission media, as well as hardware and different protocols with LAN. Data transfer rate in WAN communication is generally much lower than the LAN.

WAN Network Communications
WAN Network Technology relies on third parties, in this case Telecommunication service provider company that provides services long-distance relationship. unlike in the LAN network where the connections between devices (computers) are transmitted from one digital device / computer to other digital devices through direct physical connections, WAN technology uses a combination of analog signals and digital signals to transmit date.
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Wednesday, September 7, 2011

Japan Launches Internet Satellite Communications

SATELLITE IN JAPAN: H-2A rocket's JAXA (Japan Aerospace
Exploration Agency) to leave the anvil space launch center in Japan
in the province of Kagoshima,
The rocket carrying the satellite Kizuna,
for superfast internet system.

TOKYO-MI: Japan Aerospace Exploration Agency (Japan Aerospace Exploration Agency / JAXA), launched a rocket into outer space, carrying the satellite Kizuna was the most advanced experimental project to create a superfast internet communication network system.

The launch of domestically built rocket named H-2A was a success from the Japanese space launch center in the province of Kagoshima, after being delayed from the previous schedule on February 15 last, according to Kyodo reported in Tokyo on Saturday.

Kizuna Japanese design experts as an effort to bring wireless Internet communication system (wireless) superfast capable of reaching the Asia-Pacific region. It was also in response to the difficulty of the Internet network infrastructure on the mainland.

Geographical conditions of Japan is mountainous and rocky indeed quite difficult for the implementation of Internet networking infrastructure across the country that is being accelerated by the Japanese.

Japan eventually chose to accelerate the development of Internet network via a satellite system that does not use wires and the options as well as an effort to anticipate if a permanent communication system suffered severe interference.The ability to transfer data through Kizuna pretty awesome, which is equal to 1.2 gigabits per second. One gigabit equals one billion bits per second. With that capability, Japan is also able to accelerate technology research development broadcastinghigh-definition televisions, or often called HD-TV.Internet data transfer speeds for the Japanese public relatively quickly by using a fiber optic network data transfer speed of at least 100 megabits per second (Mbps).

The manufacturer claimed that the Kizuna satellite communication system is the fastest in the world today. Another benefit of super-fast data transfer capacity that is capable of developing long-distance medical consultation services.

The satellite is the result of collaboration between JAXA and the National Institute of Information and Communication Technology. The total cost spent on the project to reach 52 billion yen, from research, to launch the operation. 

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Friday, August 26, 2011

Infrared and how it works

Infrared light is electromagnetic wavelength than visible light is between 700 nm and 1 mm. Infrared light is invisible light. When viewed with a spectroscope the light is infrared radiation to visible light on the electromagnetic spectrum with wavelengths on the wavelength of red light. With this wavelength the infrared light will be invisible to the eye but the resulting heat radiation still feels / detected. Infrared can be divided into three areas namely:

* Near Infrared………………0.75 - 1.5 µm
* Mid Infrared....……………...1.50 - 10 µm
* Far Infrared………………….10 - 100 µm

Direct sunlight contained 93 lumens per watt of radiant flux that includes an infrared (47%), visible light (46%), and ultra violet light (6%).

Infrared rays contained in the firelight, sunlight, radiators asphalt road vehicle or a reflection of the heat affected. Nerves on our skin can menginderai differences in skin surface temperature, but We Can not feel the infrared rays. Infrared rays are used to heat food. For example even at fast-food restaurant.
How can we utilize the principle of infrared to see the objects?
We make use of infra-red detectors every object that emitted infrared and will reflect or absorb infra-red so that the detector captures a different wavelength according to the temperature of the removed objects.
"Because the main source of infra red radiation is thermal radiation or heat, every object has a specific heat that we think are not even hot enough to radiate visible light can expend energy at infrared and visible, more heat can she radiates something more infrared radiation".
This is the basis of the detection of human body temperature and detection sensors to identify people stricken with bird flu or flu Firus pigs at international airports. Many objects absorb infra red radiation, but there is also reflecting in particular near infrared light, near infra red rays are not related to the temperature of the object unless the object is very hot temperature.
Infrared film (infrared detector) on the camera can see objects aided by sunlight and other light source inssue infra red rays from it then reflected and absorbed by object. we can get a color object with the help of reflection and the absorbed infrared object, the color of the object is combination of red color blue, green (RGB) and infra red.
Infra-red can be used also as a wave cariier can extend the distance limit of wave reception, but the transmitted wave must be line of sight (LOS) or straight-infrared can not turn if the transmit radius of vertical beam was blocked by an object even though it was transparent. This theory we apply in the digital wave modulation on the remote tv. Mobile is now integrated with infrared and blue tooth devices to communicate with the pc. Examples of its application of mobile application delivery from pc or vice versa, providing a record of phone number of the pc very much that it can not be stored in phone memory is usually used for broadcasting SMS.
What is the difference infrared rays with blue tooth?
The first, uses infrared light to emit a signal, such as tv remote, while the blue tooth uses radio frequency (RF) (2.4 GHz) for broadcasting signals.
second, infra red can not penetrate objects that prevented to reach the receiver or need reflection, because of its light. However, Bluetooth can penetrate objects such as walls, as far as not having a high skin depth.
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Wednesday, August 24, 2011

QoS ( Quality Of Service )

When we first heard the word QoS or Quality of Service we would interpret it as the quality of a service. In fact, Quality of Service (QoS) is very popular and save a lot of terms that are very often seen from different perspectives namely in terms of networks (networking), application development (application development) and others.
In terms of networking, QoS refers to the ability to provide different services to network traffic with different classes. The end goal of QoS is to provide a better service network and planned to dedicated bandwidth, controlled jitter and latency and improve loss characteristics. Or QoS is the ability to guarantee delivery of critical data flow or in other words, a collection of various performance criteria that determine the satisfaction level of usage of a service.
Quality of Service (abbreviated as QoS) is a mechanism that allows applications or services can operate as expected.
Quality of Service (QoS) refers to the capability of a network to provide better service to selected network traffic over various technologies, including Frame Relay, Asynchronous Transfer Mode (ATM), Ethernet and 802.1 networks, SONET, and IP-routed networks that may use any or all of these underlying technologies. The primary goal of QoS is to provide priority including dedicated bandwidth, controlled jitter and latency (required by some real-time and interactive traffic), and improved loss characteristics. Also important is making sure that providing priority for one or more flows does not make other flows fail. QoS technologies provide the elemental building blocks that will be used for future business applications in campus, WAN, and service provider networks.

Quality of Service (QoS) is used to measure the level of quality network connection TCP / IP Internet or intranet. There are several methods for measuring the quality of the connection as the bandwidth consumption by user, connection availability, latency, losses etc.. Now we discuss the term - a term in the Quality of Service,
Bandwidth is the capacity or the capacity of an ethernet cable in order to pass traffic in a certain amount of data packets. Bandwidth can also mean the amount of consumption of data packets per unit time is expressed with units of bits per second [bps]. Internet bandwidth provided by the internet provider or ISP that we are familiar with a certain amount depending on the rental customer. With QoS we can set the user does not spend bandwidth provided by the provider.
If we transmit data at 3 Mbyte at network quiet time 5 minutes but at busy 15 minutes, this is called latency. Latency when the network is busy around 50-70 msec.
Losses is the number of packets lost during transmission of data packets to the destination, the best quality of network LAN / WAN has the least amount of losses.
Availability means the availability of a web services, smtp, pop3 and applications at the network LAN / WAN busy or not.
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