Tag Archive for access

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.

Internet Safety Laws and Online Protection Tools

Online Protection Tools

Online tools are available that will let you control your kids’ access to adult material and help protect them from Internet predators. No option is going to guarantee that they’ll be kept away from 100% of the risks on the Internet. So it’s important to be aware of your kids’ computer activities and educate them about online risks.

Many Internet service providers (ISPs) provide parent-control options to block certain material from coming into a computer. You can also get software that helps block access to certain sites based on a “bad site” list that your ISP creates. Filtering programs can block sites from coming in and restrict personal information from being sent online. Other programs can monitor and track online activity. Also, make sure your kids create a screen name to protect their real identity.

A federal law, the Children’s Online Privacy Protection Act (COPPA), was created to help protect kids online. It’s designed to keep anyone from obtaining a child’s personal information without a parent knowing about it and agreeing to it first.

COPPA requires websites to explain their privacy policies on the site and get parental consent before collecting or using a child’s personal information, such as a name, address, phone number, or Social Security number. The law also prohibits a site from requiring a child to provide more personal information than necessary to play a game or participate in a contest.

But even with this law, your kids’ best online protection is you. By talking to them about potential online dangers and monitoring their computer use, you’ll help them surf the Internet safely.

Online Protection Tools

Online tools are available that will let you control your kids’ access to adult material and help protect them from Internet predators. No option is going to guarantee that they’ll be kept away from 100% of the risks on the Internet. So it’s important to be aware of your kids’ computer activities and educate them about online risks.

Many Internet service providers (ISPs) provide parent-control options to block certain material from coming into a computer. You can also get software that helps block access to certain sites based on a “bad site” list that your ISP creates. Filtering programs can block sites from coming in and restrict personal information from being sent online. Other programs can monitor and track online activity. Also, make sure your kids create a screen name to protect their real identity.

The World’s Most Advanced 3D Mouse

Despite the fact that most professionals actively involved in technological design and engineering pretty much rely on normal mice while working in 3D modeling applications, the truth of the matter is that there are also certain specialized devices available out there, which will be able to deliver an enhanced level of functionality and improve the workflow. And that’s exactly the case with the device you’re about to see as follows, namely the SpacePilot PRO 3D Mouse, which has just been introduced by 3Dconnexion.

According to 3Dconnexion (which, by the way, is a Logitech subsidiary), the new peripheral can deliver “advanced control of 3D models, easier access to the raw power of professional 3D applications, fewer interruptions in the design workflow, and superior comfort.”

One of the main new features provided by the fresh 3Dconnexion mouse is the LCD Workflow Assistant, namely a color LCD that lists function-key assignments and provides quick access to Microsoft Outlook e-mail, calendar and task lists, allowing professionals to access important information for a fully integrated design experience.

Another important feature worth mentioning about the SpacePilot PRO is the advanced MCAD navigation system, consisting of five new dual-function QuickView Navigation keys that improve error detection, design review, and design presentation by providing one-touch access to the following views: top and bottom, right and left, front and back, two isometric views, and 90-degree view rotation of any view either clockwise or counter-clockwise – for a total of 32 views. In addition, fresh Navigation Setting keys offer simplified and customizable control, allowing users to turn pan-and-zoom, rotation and one-axis control on or off, making it easier to define navigation settings for certain work modes.

Furthermore, the device sports five new fully customizable, dual-function keys that offer immediate, one-touch access to 10 frequently used commands, at the same time being able to deliver a high level of comfort, via the sculpted, soft-coated wrist rest that positions the hand in relation to the controller cap to support a balanced workflow. The micro-precision six-degrees-of-freedom sensor allows for fingertip control with minimal effort from the arm, wrist and hand, while frequently used commands are conveniently positioned at your fingertips. The intuitive and symmetrical layout of the function keys makes the device usable with either hand.

As expected, the peripheral from 3Dconnexion is more expensive than your average peripheral, the SpacePilot PRO selling for around $499, which, however, is a price most pros may pay gladly, given the features this thing can deliver.