Tag Archive for Network

Internet Connection For Us

Needs of today’s Internet connection is vital, in which almost every country seeks to meet the bandwidth requirements for almost any home or office. In the U.S. alone some kind of connection to the Internet have been present, some of which use a dsl connection with the use of telephone lines have been installed in the home. To be able to connect to the internet via this route first we have to do the dial up settings by entering the username and password given to us by the internet service provider. Power and ease of connection is very simple because the Internet has become one with the home phone line.

In developing countries are now beginning to implement such systems. So that the dial-up internet can be done almost every home. This type of Internet connection is very much of course starting from the slowest, and certainly up to the latest technology to be able to support the performance of Internet users to be very fast. Range of mobile communication devices or PDAs are now able to function as a wireless modem connection to a PC, either via data cable, infrared or bluetooth. However, it should also keep in mind, not all types of mobile phones that support GPRS network range can be transformed into the modem. In addition to using a cell phone or PDA handset range to access the internet on a PC or laptop, which tend to be rather hot if used for too long browsing, which is more stable as an external modem that is using a USB modem, cable modem, PCMCIA data card, and Wi-Fi card.

4 Varying Kinds Of Mobile Computer Gadgets

Different kinds of portable computer gadgets may include the following: smartphones, laptops, netbook computers, and tablet PCs.

Technology has provided us with an array of choices in portable computer gadgets. These devices may have computer functions that are similar to each other, but they also have a number of other qualities that make each one standout. If you you’re planning to buy yourself one of these gadgets, go over this article to know more about each kind so you can decide which is best for you.

Smartphones

A smartphone is a combination of a personal organizer and a mobile phone. It is a little device that looks a lot more like a PDA than a regular cellphone, but it has a complex operating system to allow its “smart” features. At the same time, it also provides simplicity of use to its users. The user interface of smartphones is also better than ordinary mobile phones, with larger screens and QWERTY keypads. There are also numerous programs and productivity software that can be used on these gadgets, like mailers, organizers, spreadsheets, word processing programs, and internet browsers, among many others. Moreover, these devices boast 1 or 2 cameras and allow users take and view pictures or video clips in numerous file formats. As opposed to ordinary cellphones, smartphones can be connected in numerous ways, like through Wi-Fi, 3G, as well as WiMax. Even a LAN network is easily done with these devices. If you need to transfer files from or to your smartphone, you can either do it through USB connections or its Bluetooth feature.

Laptop computers

Also known to manufacturers as notebook computers, a laptop is a personal computer that can be brought around to such places as libraries, planes, office meetings and temporary offices. This is because, unlike desktop computers, laptops are normally smaller than an attache case and can be powered both by battery or AC. They also usually weigh less than 5 pounds and have a width of three inches or less. This gadget, though, is more costly than a desktop computer with the same attributes because of the complexity involved in trying to get all the same features into a much more compact machine. But what also make them more useful desktop computers is that they can be used either as a laptop or desktop computer.

Netbook computers

Netbook computers are new versions of laptop computers that are characterized by their size, price and a few other properties. These new devices are small, affordable, with low horsepower, and run on a system software that is either old or unfamiliar. The size of the monitors vary from 9 to 10 inches, and they have a keyboard that is quite similar to that of laptops. They also have a weight of only about 2-3 pounds. This types of computer is very convenient, indeed. However, 1 certain feature that this gadget does not have is the optical drive of laptops. CD and DVD drives have been taken out from this types of gadget to allow for its small size and weight.

Tablet PC

A tablet PC is another kind of computer that you can carry anywhere with you. With its wireless network card, you can conveniently connect to the Internet to check your email, chat with friends, update your social network status, or look for ipad support. What makes this gadget special, though, is that it does not fold or have a keyboard like that of a laptop. This device is just a single tablet that you operate either by making use of a stylus pen or the tips of your fingers.

Because these gadgets are available in varied prices and with different features, it is essential that you ascertain your needs first and then choose the gadget that is closest to the rate you can afford, and also offers the most important features for you. Be well informed before making a decision.


Adaptations in Prairie Dogs

Why do we call an animal which looks like a squirrel and behaves like a meerkat, a dog? This will probably be the first question that pops up in your head. Well, prairie dogs are called so because of the barking sounds that they make. Irrespective of their barking, they are so cute that, most of you will want a prairie dog as a pet. There are 5 types of prairie dogs which are found in North America, they are:

  • Black-tailed prairie dogs
  • White-tailed prairie dogs
  • Utah prairie dogs
  • Mexican prairie dogs
  • Gunnison’s prairie dogs

All the above types have adapted well to the prairie. Their adaptations are not restricted to their anatomy, they show interesting social and behavioral adaptations too.

Adaptations of Prairie Dogs

Prairie dogs are highly social animals, they live in groups. A network of burrows made by them is called a “town”. Each town is composed of several “wards”, and each ward has numerous “coteries” (or clans). A coterie generally comprises a family, which includes a dominant male, females, and their offspring. There is a sense of bonding among the members in a coterie, this closely resembles the nature of the human family. The adaptations of prairie dogs can be stated as follows:

Sharp Teeth
The prairie dogs are herbivores (but they do consume insects occasionally), so they feed on plants and fruits that the prairie provides them. They have sharp incisors, which help them to consume the tough plants in the prairie region.

Strong Hind Legs
The prairie is characterized by tall grass, so it is very difficult for animals to spot any potential dangers. The prairie dogs have very strong hind legs, which allow them to stand erect, thus allowing them to have a better lookout.

Tough Claws
A “town” of prairie dogs can extend up to a few miles. The burrows made by them are highly complex. Their claws are the tools that they use to build their “town”. The prairie dogs also feed on roots when the plants have dried up. Their claws help them to dig out the roots.

Acute Vision
The prairie dogs are equipped with acute vision, which allows them to locate any predator hiding in the tall grass. Their vision helps them identify predators from a considerable distance, thus giving them time to run and take shelter.

Camouflage
The best way to stay hidden from predators is to blend into the surrounding. The characteristic brownish fur of prairie dogs helps them to camouflage themselves.

Barking Sound
Every family of prairie dogs posts a sentinel. The sentinel stays alert while the others forage. When the sentinel anticipates danger, he makes a barking sound, thereby signaling others to run for safety.

Flood Relief
The burrows of the prairie dogs might get flooded in case of heavy rains. The prairie dogs have adapted themselves to such a situation. They remain safe from floods as they have special chambers in their burrows which serve as air pockets.

Winter Break
Along with intense cold, the winter also results in shortage of food. Their fur keeps the prairie dogs warm in the winters. They hibernate during winter, thus they are not affected by the scarcity of food in winters.

The “kissing” of prairie dogs has caught the attention of many wildlife enthusiasts. When they “kiss”, they are actually smelling one another. “Kissing” is probably the only way in which they can identify their close relatives. The prairie dogs make a mound near their burrow, and cut the tall grass around their burrow, so that the sentinel has a better view. 

Prairie dogs are fascinating, they were found in great numbers, but their population has reduced significantly over the years. Man has been a major cause for this reduction. If adequate measures are not taken, one day they will vanish from the surface of the Earth!

Satellite broadband

Satellites in geostationary orbits are able to relay broadband data from the satellite company to each customer. Satellite Internet is usually among the most expensive ways of gaining broadband Internet access, but in rural areas it may be the only choice other than cellular broadband. However, costs have been coming down in recent years to the point that it is becoming more competitive with other broadband options.

Broadband satellite Internet also has a high latency problem is due to the signal having to travel to an altitude of 35,786 km (22,236 mi) above sea level (from the equator) out into space to a satellite in geostationary orbit and back to Earth again. The signal delay can be as much as 500 milliseconds to 900 milliseconds, which makes this service unsuitable for applications requiring real-time user input such as certain multiplayer Internet games and first-person shooters played over the connection. Despite this, it is still possible for many games to be played, but the scope is limited to real-time strategy or turn-based games. The functionality of live interactive access to a distant computer can also be subject to the problems caused by high latency. Additionally, some satellite Internet providers do not support VPN due to latency issues.[6] These problems are more than tolerable for just basic email access and web browsing and in most cases are barely noticeable.

For geostationary satellites there is no way to eliminate this problem. The delay is primarily due to the great distances travelled which, even at the speed of light (about 300,000 km/s (190,000 mi/s)), can be significant. Even if all other signalling delays could be eliminated it still takes electromagnetic radio waves about 500 milliseconds, or half a second, to travel from ground level to the satellite and back to the ground, a total of over 71,400 km (44,400 mi) to travel from the source to the destination, and over 143,000 km (89,000 mi) for a round trip (user to ISP, and then back to user—with zero network delays). Factoring in other normal delays from network sources gives a typical one-way connection latency of 500–700 ms from the user to the ISP, or about 1,000–1,400 milliseconds latency for the total Round Trip Time (RTT) back to the user. This is far worse than most dial-up modem users’ experience, at typically only 150–200 ms total latency.

Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellites however do not have such great delays. The current LEO constellations of Globalstar and Iridium satellites have delays of less than 40 ms round trip, but their throughput is less than broadband at 64 kbit/s per channel. The Globalstar constellation orbits 1,420 km above the earth and Iridium orbits at 670 km altitude. The proposed O3b Networks MEO constellation scheduled for deployment in 2012 would orbit at 8,062 km, with RTT latency of approximately 125 ms. The proposed new network is also designed for much higher throughput with links well in excess of 1 Gbit/s (Giga bits per second). The planned COMMStellation™, scheduled for launch in 2015, will orbit the earth at 1,000 km with a latency of approximately 7 ms. This polar orbiting constellation of 78 microsatellites will provide global backhaul with throughput in excess of 1.2 Gbit/s.

Most satellite Internet providers also have a FAP (Fair Access Policy). Perhaps one of the largest disadvantages of satellite Internet, these FAPs usually throttle a user’s throughput to dial-up data rates after a certain “invisible wall” is hit (usually around 200 MB a day). This FAP usually lasts for 24 hours after the wall is hit, and a user’s throughput is restored to whatever tier they paid for. This makes bandwidth-intensive activities nearly impossible to complete in a reasonable amount of time (examples include P2P and newsgroup binary downloading).

Some systems have a FAP based on a monthly limit of data downloaded, with download data rates reduced for the remainder of the month if the limit is exceeded. Other Satellite Internet offers have advanced FAP mechanisms based on sliding time windows. These services verify download quotas during the last hours, days and weeks. The purpose is to allow temporary excessive downloads when needed while saving volume for the end of the month.

Advantages

  1. True global broadband Internet access availability
  2. Mobile connection to the Internet (with some providers)

Disadvantages

  1. High latency compared to other broadband services, especially 2-way satellite service
  2. Unreliable: drop-outs are common during travel, inclement weather, and during sunspot activity
  3. The narrow-beam highly directional antenna must be accurately pointed to the satellite orbiting overhead
  4. The Fair Access Policy limits heavy usage, if applied by the service provider
  5. VPN use is discouraged, problematic, and/or restricted with satellite broadband, although available at a price
  6. One-way satellite service requires the use of a modem or other data uplink connection
  7. Satellite dishes are very large. Although most of them employ plastic to reduce weight, they are typically between 80 and 120 cm (30 to 48 inches) in diameter.