Worlds Top 3 Broadband Cities

Worlds Top 3 Broadband Cities By Adair Cameron

Broadband technology has improved so much over the last few years that we couldn’t imagine a world without it anymore. This improvement has been seen most notably in the Eastern World where the technology is unmatched. These are the top three broadband cities in the world.

1. Seoul, South Korea

The Capital City of South Korea is home to 10 million people and claims top spot for highest broadband penetration with an impressive 83%. Seoul offers 10Mbit/s broadband connections averaging at £10 per month and some areas offer 100Mbit/s broadband from as little as £15 per month.

Koreans have a fascination with online PC Gaming unlike anywhere else in the world with several TV stations dedicated to the so-called sport. Seoul plays the biggest part and is one of the main reasons for the ever-expanding usage of broadband internet in South Korea.

Current expansion plans include a $439 million project to add wireless internet access to subway trains which has more than 8 million passengers per day.
Broadband service is second to none, and this is why the city takes top spot.

2. Taipei, Taiwan

The Capital City of Taiwan claims top spot for wireless broadband. In 2004 the Mayor of Taipei set out to make the city a “cyber city” and was successful within 3 years. Over $70 million was spent to build a wireless broadband network of more than 20,000 access points with enough range to provide broadband for 90% of the population. This is very impressive considering this wireless network covers an area of 105 square miles. The cost to gain access to the citywide wireless broadband network ranges from £2.50 to £12 per month.

Taipei has to settle for second place due to Seoul’s broadband penetration, but it’s number one in the world for wireless broadband.

3. Tokyo, Japan

Tokyo is the largest metropolitan area in the world and has tens of millions of people connected to broadband. Due to great speeds and availability Tokyo broadband users are able to obtain video web conferencing and VoIP call services with more than 10 million unique IP lines in Tokyo alone. Broadband is fairly cheap too, with the most popular option being 100Mbit/s broadband for £25 per month, although there is a 1Gbit/s broadband option at £45 per month.

By 2010, NTT (Nippon Telegraph and Telephone) plans to have spent more than £20 billion in renovations that include plans to provide a ubiquitous cable broadband service for the entire country’s 45 million households.

Therefore, for raw broadband speed and the most amount of users, Tokyo would definitely claim number one spot, but it falls down to third place in the top broadband cities because of a low overall broadband penetration rate.

Six Things You Don't Know About Broadband

Six Things You Don't Know About Broadband By Jerry Niu

Do you know broadband?You may answer yes. I know you may have tried different broadband from several broadband ISPs. You may have installed broadband by yourself several times. You know broadband speed - 2Mb, 8Mb or 24 Mb. You may understand the monthly usage and control your usage. But if you are not a technician in that area, you may not know everything behind these numbers. There is something broadband ISPs will not tell you, or try to write it in a shady corner on their web page.

Let me tell you all these things:

Price:

As more and more ISPs have packages, the price became more and more incomparable. Some packages like Talktalk have call bundles (including anytime package or off-peak package), some are combined with mobile phone contract, and some deals are only available to TV Program subscribers.

A main problem is most deal descriptions don't show whether the price contains the line rental. They may wish customer forget the existence of line rental. But usually, if the deal doesn't tell you that, it means the line rental is not included in the price. If the line rental is included, no ISP will forget to tell you.

Speed:

When we talk to speed, I should tell you broadband ISPs are playing two tricks in words.

The first is the unit. They usually use Mb to describe the speed. Do you think if the speed can reach the theoretic max speed, you can download a song in MP3 format (about 4MB) in half a second? You are tricked. In computer, the size of the file is displayed in MB, which means MegaByte. While in broadband specification, speed is showed in Mb, which means Megabit. 1 MegaByte = 8 Megabit. So 8Mb per second means 1 MB per second.

Another instance I have to emphasise is: Do ask your broadband ISP the maximum speed your phone line can support. Because not all the phone line in UK support 8Mb broadband. Phone lines in some areas can only reach 2Mbps. If your telephone line can't support fast speed, it's a waste of money to buy fast broadband. And I know some ISP don't check it for customers and just open fast broadband for customers no matter real speed the phone line can reach.

Connection Rate:

Now, we know the actually speed broadband ISPs provide to us. However, there is another bad news - you may have to share the bandwidth with other 49 people.
So in Internet rush hour, the real speed may be slow down to 160 Kb a second. That is 20 KB per second.

Wonder why? Because there is a connection rate for broadband! Few broadband ISPs tell customers its connection rate on an explicit place on the web site. But it does affect the speed a lot.

So what is connection rate? Connection rate shows the number of users who share the bandwidth on a single broadband connection between your local exchange and your broadband ISP. Normally, the connection ratios are 50:1 and 20:1.

In UK, the connection rate for home broadband is 50:1, which means you would likely to share your bandwidth with 49 other users, of course, never more than that number. The connection ratio for business broadband is 20:1. It will be much faster in Internet rush hour.

Usage:

Are you annoyed because many providers set a monthly usage cap for broadband, so that you have to check all the time how much you used? Are you looking for broadband with unlimited usage? But you have to consider this instance, if one broadband provider offers unlimited broadband, and customers of this broadband will try and use it all the time. Most providers offer unlimited broadband will have a fair use policy, which actually is led by the connection rate. As there is a connection rate exists, usually 50 people share one line between the exchange and the broadband ISP, so many people will cause the broadband network grind to a halt. This not only makes your broadband speed slows down, but also makes the volume you download decrease largely.

Let me do some calculation, if there are always 40 people (as we have seen, one line may be shared by 50 people) using an 8Mb speed broadband, then the real speed for each person is 200Kb/s. That is 25 KB per second. So you can download as much as 90 MB in one hour, in theory. If you download 12 hour a day, 30 days a month, you can download as much as 32 GB. This number is less than some deals with 40 GB monthly cap. So, don't only looks at the unlimited broadband, even if you download a lot, some deals with large monthly cap provide almost the same volume you can download.

However, a good news is, the monthly download limit or we say monthly usage cap is measured by GB, not Gb. There are no tricks this time.

Contract Length:

Even last year, there is few broadband provider offer broadband with no contract. But now there are several broadband ISP offering no contract broadband, for example, PlusNet, NamesCo, Eclipse.

Those broadband which are so called "no contract broadband" do have contract length. Usually they are one-month rolling contracts. If you don't wish to go on with that broadband provider, call that provider and ask for disconnection. The contract will end at the end of the contract period.

And some providers offer free connection or free modem even if you commit such one-month contract. But if you disconnect within a certain period (usually 12 months), you have to pay for the connection fee and modem fee. So, if you wish to get those broadband, read their terms and conditions carefully.

Availability:

When you check broadband availability of a certain provider, the checker may tell you that that broadband is available in your area. But later, when you plan to install broadband from that provider, you may told that you have to pay more than the price shown on the web site to get that broadband.

What's happened? The reason is some broadband ISP use two types of network. They have their own broadband exchanges in some areas. In some place elsewhere, they provide broadband service by BT network. The cost is different, leading the different price in different areas. As far as I know, Sky Broadband and TalkTalk Broadband have such differential price policy. And Orange also use two networks, but their price are the same.

Broadband Deals

Broadband Deals - Is Contract Broadband for You? By James Dyson

You are sure now that broadband is for you but not on what term or basis you want to have it. Better understanding of the packages and their norms offered by the providers and by calculating them along with you needs and other aspects, you can find out a better option.

Are you flexible with your broadband deal? In the competitive market, you will be hearing of new services launched every month, in which you may find one to be a better deal for yourself. So switching to that provider may sure save your money and for it, your existing broadband connection should allow it without charging in volume for disconnecting the service.

Who should not have a broadband contract? If you want a broadband for your short-term requirement or if you are planning to move your house soon then you can just ignore the contract broadband option at very first.

Moreover, there is lot to benefit from a package having no contract because you can cancel your broadband connection whenever you want and most providers charge only up to the last month of using the service.

Suppose you sign for a long-term contract package and in mid of the contract time, you are forced to leave the service because of any of your reason then you might need to pay the monthly charges for the whole contract time. For example if the service is of 12 months contract then you have to pay charges for 12 months even if you do not make use it.

Broadband on monthly contract In the UK, most of the ISPs ask to sign for a 12 months contract and demand to pay additional charges in case of discontinuing in between. So if you really want ease in having the service then you have to look for other available packages and recognize them before.

Broadband on monthly contract is one that you can sign up. This gives you the flexibility of canceling your service any time with prior one-month notice to the provider. Many ISPs in the UK offer this type of broadband.

Still you need to be well clear with the charges like monthly subscription charges in which providers charge more if you have not signed it for long term. This is mainly done to cover their overall costs. A low priced 12 months contract and 10 months contract under monthly contract basis may cost same. So if you are in need to have a broadband connection for 11 months only, you can sign up for a year time contract instead.

Pay as you go broadband For home users, pay-as-you-go broadband option should be the preferable choice. As home users does not use much for downloads and uploads, the option serves their exact needs as the users pay only for the actual usage which is calculated in terms of uploads and downloads.

Therefore, users who are very much cautious about their spending can have the pay-as-you-go broadband. Some providers even make available the cost capping facility to the users that the users can have a control on their monthly charges.

How well you require being clear with yourself, to have a broadband or not, to that extend you need to be well clear on what fee basis your broadband should be. For the most part, it depends upon the circumstance you are going to be with and planning accordingly will help you in choosing the broadband package for you.

Insight Broadband

Insight Broadband By Alen Wilson

Gone are days when logging on to the World Wide Web was a nightmare, owing to the erratic behavior displayed by the dial-up type of internet access. Now we have a very dependable option and that’s ‘BROADBAND’

Broadband internet connection is growing in prominence as the technology of choice for internet access due to the variety of benefits it gets associated with.

The principal advantages are:

- Super fast speeds

- Always ON type of connection

- Keeps phone lines free

- Reliable

- Scalable

But how does broadband make all this possible? To get an answer to that question we have to look a little deeper into the technological aspects of broadband.

Definition of broadband

Broadband is defined as ‘A mode of data transmission, where multiple pieces of data are sent simultaneously to increase the effective rate of transmission’. In simple terms it means that a number of different pieces of information which may be data, audio or video in nature can be sent simultaneously over a single cable. What that transforms into is that we have optimum utilization of bandwidth. That’s why this way of sending data was termed BROAD-BAND.

Types of broadband

There are a number of types of broadband connections like DSL, CABLE, SATELLITE, WIRELESS and ADSL. The choice with respect to the type of connection to be used entirely depends on the intended use and affordability.

- Digital subscriber line (DSL): A technology ideal for business ensures high speed uploads and downloads.

- CABLE: Broadband through your local cable TV connection.

- SATELLITE: A boon for people living in remote areas.

- WIRELESS: land based wireless broadband.

- Asymmetric digital subscriber line(ADSL): Ideal technology for home users.

As far as application of broadband in home environment is concerned ADSL is widely accepted as the technology of choice.

Accessing broadband

The emergence of broadband technology saw a concurrent surfacing of broadband service providers, these service providers act as the link between you and the World Wide Web. So a reliable broadband service provider is of critical importance, as the quality of his services would decide whether you like broadband or not!

Hardware and software requirements

The hardware requirements would entirely depend on the type of broadband technology you want to get associated with.
No additional software is required to get into the broadband bandwagon, but it would be helpful if you are using a newer version of operating systems.

Limitless functionality

We all have seen the movie ‘STARWARS’ and wondered about the technology they employ and at the end of the movie came out thinking all that as distant imagination. But with broadband many of the so called impossible technologies have come to our door steps. Now we can create virtual private networks, video conference, talk internationally at very cheap rates! Aren’t these the stuffs of which dreams are made of!

Broadband in a sense is challenging us by testing the limits of our imagination. We imagine and it provides!

So let your imagination loose by logging on to the surreal world of BROADBAND. Get in touch with a broadband service provider in your area and give your imagination the wings to fly...

Broadband Review

Broadband Review By Rob Michael

The Uses Of Broadband

Broadband is a high-speed Internet connection that provides a large bandwidth. It is considered a very quick connection. It is an "always-on" type of connection and can transmit data at a much faster rate than your usual dialup connection. Broadband also has the added advantage of not tying up your phone line, which means you can use the both the Internet and telephone at the same time. Broadband can be provided from a variety of sources, including over the top of your phone line as in ADSL or on dedicated line such as Cable or ISDN.

Typically, low-band Internet access is running up to 56kbps using a dial-up modem. Mid-band Internet is described as dialup access that operates at 64kbps or 128kbps. Standard broadband starts at 512kbps, which is about five times faster than dial-up service. Broadband is also available at 1mbps, 1.5mbps and 2.2mbps. There are companies that offer broadband at 4mbps and 8mbps. The maximum possible for cable is around 26mbps and 24mbps for ADSL. These speeds are not sold commercially because the cost to upgrade the telephone lines to be able to transmit data at these speeds is very high.

Downloading and streaming music and video is very quick with broadband. There are a lot of websites now that are designed especially for broadband users. They have intense integrated graphics, flash and video. Broadband is also popular for online gaming. Game consoles like Xbox and PS2 have broadband support included. You can then subscribe to different types of gaming packages from your current ISP, which makes it possible to play Xbox and PS2 games live with other gamers over the Internet. Actually, online PC gaming has been going on since the Internet came into use, but in the past it was difficult to do. Slow and jerky response from your computer made it hard to play, and you always had to keep an eye on the time. Now, with the faster speeds of broadband, it has become much easier and is quickly gaining in popularity. Some games are now being released that require an Internet connection to play.

The growing popularity of broadband has made it necessary for most providers to put a maximum limit on the amount of music, video and other data you can download. This limit can vary greatly, from as low as 1 GB up to 30 GB. Extreme users can get unlimited downloads if they wish. However, exceeding your ISP's download limit usually results in having a limited connection or no connection at all.

One of the possible futures of broadband is Internet Television. The current bandwidth, which is the amount of data you can send and receive, is not wide enough to provide an image that is of comparable quality to that of your standard television. The ever- increasing broadband speeds will make Internet Television a reality. Since you can currently download clips from the shows, music videos and other content you like, it will soon be possible to do it legally in real time. Another use of broadband is online telephony. This is software that allows you to use your computer as a telephone and talk to people from anywhere without any extra cost. It is becoming commonplace, and has a higher quality or recording than a traditional telephone line. With the increase in the speeds of broadband, it may soon replace your television and telephone, and will find its way into every home. The success of broadband is making the Internet a great resource that's easy to use and fun to access for a variety of needs.

ASTRA2Connect

From Wikipedia, the free encyclopedia

Example of the terminal dish used to access the ASTRA2Connect system in Europe

ASTRA2Connect is a two-way satellite broadband Internet service available across Europe, which launched in March 2007, and uses the ASTRA series of geostationary satellites. ASTRA2Connect is owned and operated by ASTRA Broadband Services (ABBS), a subsidiary of SES ASTRA^[1], itself a subsidiary of SES based in Betzdorf, Luxembourg.

ASTRA2Connect provides high-speed Internet access (at up to 2Mbit/s) at a flat rate cost to end users, along with VoIP, IPTV, and content-on-demand facilities, without any requirement for a landline, cable or terrestrial wireless connection.

Application

Close up of the receive/transmit iLNB used on the ASTRA2Connect terminal dish

The ASTRA2Connect service makes broadband Internet access available to homes in rural locations or otherwise beyond the reach of existing terrestrial broadband services. Outside the major European urban centres, there are millions of households currently without broadband access through landlines.^[2] and by 2010, up to 6million, or 3.5%, of the 170 million homes in Western Europe will still be without terrestrial broadband access.^[3]

ASTRA2Connect can also be used for transportable broadband Internet access, where the location or its temporary nature prohibits a terrestrial connection, although the equipment requires mains power and cannot be used while actually in motion.

As well as Internet access, ASTRA2Connect is used for dual play (broadband internet and telephony) and triple play (broadband Internet, telephony and TV) services^[2].

An upgrade was introduced in 2008 to enable an ASTRA2Connect dish to be used for simultaneous reception of normal satellite TV from satellites at the Astra 19.2°E or the Astra 28.2°E positions.

Technology

ASTRA2Connect uses a satellite link to carry IP data in both directions between the central hub and remote terminals. At the hub, routers connect to the Internet backbone and IP data is embedded in a DVB-S2 format carrier to be uplinked to the satellite from SES ASTRA’s teleport and, from there, downlinked to the remote terminal where the signal is received with a domestic-type dish for the satellite internet modem, which extracts the IP data for the end user’s PC.

The return path is handled in a similar fashion, but with a low power 500mW transmitter on each terminal dish providing the uplink to the satellite, with multiple-frequency time division multiple access techniques employed to handle many remote terminals simultaneously. ASTRA2Connect combines 2 standards for the return path: Satmode for modulation and coding and DVB-RCS for the access scheme.

The central hub and terminal technology is developed by a Belgian company called Newtec.

ASTRA2Connect uses the Astra 1E communications satellite at the 23.5° east orbital position to handle uplinks and downlinks in both directions. A number of transponders are used for the hub-to-terminal downlink in the satellite TV downlink segment of the Ku band (10.70GHz-12.75GHz). The terminal-to-hub uplink to the satellite uses using the uplink segment of the Ku band (14.00GHz-14.50 GHz) and extended Ku band (13.75GHz-14.25GHz)

Marketing

The IPmodem used to connect the iLNB to the user’s host PC or local area network

ASTRA2Connect services are sold to residential users by a number of ISPs in partnership with SES ASTRA. Such partnerships operate either exclusively or in competition within different regions and countries of Europe. Germany was the first country to receive access to ASTRA2Connect services. SES ASTRA currently has partnerships with ISPs to provide ASTRA2Connect services in Austria, Belgium, France, Germany, Ireland, Italy, Netherlands, Poland, Slovenia, Switzerland,^[4] Spain^[5] and the UK, with partnerships in other countries under negotiation.^[6]

The first ASTRA2Connect service provider in Germany was ISP, Filiago^[7] which is responsible for marketing and selling the ASTRA2Connect service, providing home and business installations, billing, and running a subscriber helpdesk. SES ASTRA provides the ASTRA2Connect satellite capacity, a DVB/IP Internet platform, uplink services, Internet backbone connectivity, subscriber activation and monitoring, and technical support for Filiago.

Customers of Filiago purchase the ASTRA2Connect terminal equipment for €320, pay a €100 registration fee and a flat rate monthly fee according to the maximum speed – €20 for 256Kbit/s download, 64Kbits/s upload, €30 for 512Kbit/s download, 96Kbits/s upload, €40 for 1024Kbit/s download, 128Kbits/s upload, or €80 for 2048Kbit/s download, 128Kbits/s upload.^[8]

User Equipment

Connection to the ASTRA2Connect service is by way of a Sat3Play satellite terminal developed by Newtec^[9] in conjunction with the European Space Agency (ESA). The terminal comprises an external satellite dish fitted with a two-way interactive LNB (“iLNB”) connected by coaxial cable to the indoor satellite “IPmodem” that, in turn, connects to the user’s PC or LAN. Assembly of the dish and installation is straightforward and requires only a few basic tools and a simple signal strength meter. The installation is sometimes referred to as Do-It-Yourself (DiY) installation. Detailed instructions for installation are supplied and this can be achieved by any competent end user, without professional help.^[10]

The satellite dish is of an offset design with an 80 cm diameter solid steel reflector and fitted with an altazimuth mount.

The iLNB combines the feedhorn and electronics for reception and transmission in one unit, and is provided with two F connectors for receive and transmit connection to the IPmodem. The reception (download) section is equivalent to a universal LNB used in a European domestic direct broadcast satellite TV system but provides for reception of one signal polarity only (selection of the correct polarity at installation is obtained by rotating the iLNB within its mount on the dish).

The IPmodem is a small plastic-cased mains powered unit with F connectors for connection to both receive and transmit sections of the iLNB. It requires no software on the end user’s PC and connects directly, or via a LAN using a standard RJ45 Ethernet connector.

The terminal acts as a DHCP server for the computer, and provides LED indicators for power, satellite link alarm, LAN connection, LAN data, satellite signal received and satellite transmission. With the dish aligned correctly on the correct satellite, the IPmodem automatically seeks out the initial receive carrier frequency (10.891GHz) and establishes a satellite connection.

To enable an ASTRA2Connect dish to be used for normal satellite TV reception, a "Quad LNB and Multifeed Clamp" upgrade can be fitted to the terminal dish. This comprises a replacement clamp for the iLNB onto which fits an additional LNB clamp for either Astra 19.2°E or Astra 28.2°E, fixed at the correct horizontal separation and adjustable vertically (for the user's latitude). A special four-output LNB is supplied, which contains filtering to suppress interference from the iLNB's transmitter.^[11]

Performance

Rear panel of the IPmodem of the ASTRA2Connect satellite broadband system showing the two receive and transmit F connectors and the RJ45 network connection

ASTRA2Connect provides an always-on connection but overall downloaded data is limited by a "fair use" policy. More than 2Gbyte of data downloaded per month reaches the fair use limit, and access speed is then automatically throttled.^[12] However, the speed is restored to the maximum at the start of each month. Moreover, tests conducted by German consumer magazine, PC Magazin, found the limit was not a practical constraint: "Despite violent download orgies, we didn’t come up against the 'Fair Policy'. We had the full 1024Kbit/s at our disposal for the whole test period"^[13]

German consumer magazine, SatVision declared the ASTRA2Connect speed "Good" with a score of 83.3%,^[14] while PC Magazin found "The speed of the data transfer is what you’d expect from 1Mbit/s access. Our tests rushed through the ether at about 115Kbyte/s."^[15]

Since these tests, the maximum download speed has been increased and now stands at 2Mbit/s, with a maximum upload speed of 128Kbit/s,^[16] which puts ASTRA2Connect on par with practical terrestrial broadband connections.

Potential drawbacks of satellite broadband systems include the lack of security of the download data (which can be received by anyone within the satellite’s footprint) and the delay inherent in the connection – as both upload and download data must follow the route from the ground to the satellite (located some 35,785km above the Earth) and back, there is a minimum total delay or latency (depending on the location of the receive site) of about 0.5 seconds.

ASTRA2Connect data transmission features two-way TCP encryption to provide security, and data compression, TCP-acceleration, and HTTP pre-fetching (at the server and subscriber ends) to alleviate the effects of satellite latency.^[17]

Digital Fernsehen magazine’s tests of ASTRA2Connect found that "two-way connection via satellite is unsuitable for lovers of on-line games. The Ping times measured are too long for this application, with values of 578ms-589ms".^[18] However, PC Magazin’s tests found: "The echo (Ping) times were around 650ms. For large downloads, that is insignificant and while surfing on the Internet, it’s easy to accept a half-second 'time to reflect'."^[19]

References

1. ^ SES ASTRA (September 12, 2008). SES ASTRA Creates New Broadband Company. Press release. http://www.ses-astra.com/business/en/news-events/news-latest/index.php?pressRelease=/pressReleases/pressReleaseList/08-09-12/index.php.
2. ^ ^{a b} SES ASTRA "ASTRA2Connect Broadband internet access and VoIP". (August, 2007). Company factsheet
3. ^ Holmes, Mark. "2007: Pivotal Year For Satellite Broadband In Europe" Via Satellite (December, 2007) 19-20
4. ^ "ASTRA2Connect". SES ASTRA. http://www.ses-astra.com/consumer/en/astra-broadband/astra2connect/index.php. Retrieved on April 23 2008. Company website
5. ^ SES ASTRA (October 1, 2008). SES ASTRA Launches ASTRA2CONNECT In Spain. Press release. http://www.ses-astra.com/business/en/news-events/news-latest/index.php?pressRelease=/pressReleases/pressReleaseList/08-10-01/index.php.
6. ^ SES ASTRA (January 15, 2008). Satellite Broadband Service ASTRA2Connect Expands To France and Italy. Press release. http://www.ses-astra.com/business/en/news-events/news-latest/index.php?pressRelease=/pressReleases/pressReleaseList/08-01-15/index.htm.
7. ^ Filiago GmbH http://www.filiago.de German ISP partner.
8. ^ "ASTRA2Connect End User Prices (Germany)". Filiago. http://www.filiago-shop.de/sess/utn;jsessionid=15481055d4ef14e/shopdata/index.shopscript. Retrieved on October 18 2008.
9. ^ Newtec Company NV http://www.newtec.eu Terminal manufacturer
10. ^ SES ASTRA "Manual for the ASTRA2Connect Terminal" version 1.6.5. (March 3, 2007). Instruction manual
11. ^ SES ASTRA "ASTRA2Connect: Upgrade for TV reception" (October, 2008). Company factsheet
12. ^ Sülzer, Torsten. "DSL für ländliche Regionen" Kölnische Rundschau (April 3, 2008) (German) "Werden mehr als zwei Gigabyte Daten pro Monat geladen, greift die „Fair Trade Policy“ - dann wird der Zugang automatisch gedrosselt."
13. ^ Pichl, Günter. "Über-All Internet" PC Magazin (July, 2007) 52-53 (German) "Trotz heftiger Download-Orgien kamen wir mit der „Fair Policy“ nicht in Konflikt. Wir hatten während des gesamten Testzeitraums die vollen 1024Kbit/s zur Verfügung."
14. ^ Szigat, F. "Das Internet aus dem All" SatVision (August, 2007) 44-46 (German)
15. ^ Pichl, Günter. "Über-All Internet" PC Magazin (July, 2007) 52-53 (German) "Die Geschwindigkeit der Datenübertragung entspricht dem, was man von einem 1 Mbit/s-Zugang erwarten darf. Rund 115 kByte/s rauschten bei unseren Tests über den Äther."
16. ^ SES ASTRA "ASTRA2Connect" (September, 2008). Company factsheet
17. ^ Newtec Productions NV "TP200 Sat3Play Broadband Terminal" (Version R2/01.2008). Company factsheet
18. ^ Meyer, Thomas. "Praxistest Internet via Satellit" Digital Fernsehen (September, 2007) 86-87 (German) "Nicht geeignet ist die Zwei-Wege-Verbindung via Satellit für Liebhaber von Online-Spielen. Die von DF gemessenen Ping-Zeiten, d. h. die Zeiten, die „Astra 2 Connect“ benötigt, um eine Seite wie www.digitalfernsehen.de aufzurufen, sind für diese Applikation mit Werten von 578 bis 589 Millisekunden zu lang."
19. ^ Pichl, Günter. "Über-All Internet" PC Magazin (July, 2007) 52-53 (German) "Allerdings lagen die Antwortzeiten (Ping) im Bereich von rund 650 ms. Für größere Downloads ist das belanglos und auch beim Surfen im Internet ist die gute halbe Sekunde „Bedenkzeit“ leicht zu verschmerzen."

See also

• Astra 1E satellite carrying the service
• HughesNet US satellite Internet service
• StarBand US satellite Internet service
• WildBlue US satellite Internet service

External links

• ASTRA2Connect website
• SES Astra website
• SES Astra interactive fleet map

Retrieved from "http://en.wikipedia.org/wiki/ASTRA2Connect"

Categories: Satellite Internet | Broadband | Internet | Internet companies | Internet service providers | Direct broadcast satellite services | Satellite television | Interactive television | Telecommunications companies of Luxembourg | Betzdorf

Very small aperture terminal (VSAT)

from wikipedia

A 2.5 m parabolic dish antenna for bidirectional Satellite Internet Access.

A Very Small Aperture Terminal (VSAT), is a two-way satellite ground station with a dish antenna that is smaller than 3 meters. Most VSAT antennas range from 75 cm to 1.2 m. Data rates typically range from narrowband^[vague] up to 4 Mbit/s. VSATs access satellites in geosynchronous orbit to relay data from small remote earth stations (terminals) to other terminals (in mesh configurations) or master earth station "hubs" (in star configurations).

VSATs are most commonly used to transmit narrowband data (point of sale transactions such as credit card, polling or RFID data; or SCADA), or broadband data (for the provision of Satellite Internet access to remote locations, VoIP or video). VSATs are also used for transportable, on-the-move (utilising phased array antennas) or mobile maritime communications.

Usage

The first commercial VSATs were C band receive-only systems by Equatorial Communications using spread spectrum technology. More than 30,000 60 cm antenna systems were sold in the early 1980s. Equatorial later developed a C band (4/6 GHz) 2 way system using 1 m x 0.5 m antennas and sold about 10,000 units in 1984-85.

In 1985, Schlumberger Oilfield Research co-developed the world's first Ku band (12-14 GHz) VSATs with Hughes Aerospace to provide portable network connectivity for oil field drilling and exploration units. Ku Band VSATs make up the vast majority of sites in use today for data or telephony applications.

The largest VSAT network (more than 12,000 sites) was deployed by Spacenet and MCI for the US Postal Service. Other large VSAT network users include Walgreens Pharmacy, Dollar General, Wal-Mart, CVS, Riteaid, Yum! Brands (Taco Bell, Pizza Hut, Long John Silver's and other Quick Service Restaurant chains),Intralot, GTECH and SGI for lottery terminals. VSATs are used by car dealerships affiliated with manufacturers such as Ford and General Motors for transmitting and receiving sales figures and orders, as well as for receiving internal communications, service bulletins, and interactive distance learning courses from manufacturers. The FordStar network, used by Ford and its local dealers, is an example of this.

VSAT technology is also used for two-way satellite Internet providers such as HughesNet, StarBand and WildBlue in the United States; and ASTRA2Connect across Europe. These services are used across the world as a means of delivering broadband Internet access to locations which cannot get less expensive broadband connections such as ADSL or cable internet access; usually remote or rural locations.

Nearly all VSAT systems are now based on IP, with a very broad spectrum of applications. As of December 2004^[update], the total number of VSATs ordered stood at over 1 million, with nearly 650,000 in service. Annual VSAT service revenues were $3.88 billion (source: www.comsys.co.uk).

Configurations

Most VSAT networks are configured in one of these topologies:

• A star topology, using a central uplink site, such as a network operations center (NOC), to transport data back and forth to each VSAT terminal via satellite,
• A mesh topology, where each VSAT terminal relays data via satellite to another terminal by acting as a hub, minimizing the need for a centralized uplink site,
• A combination of both star and mesh topologies. Some VSAT networks are configured by having several centralized uplink sites (and VSAT terminals stemming from it) connected in a multi-star topology with each star (and each terminal in each star) connected to each other in a mesh topology. Others configured in only a single star topology sometimes will have each terminal connected to each other as well, resulting in each terminal acting as a central hub. These configurations are utilized to minimize the overall cost of the network, and to alleviate the amount of data that has to be relayed through a central uplink site (or sites) of a star or multi-star network.

Technology

VSAT was originally intended for sporadic store-and-forward data communications but has evolved into real-time internet services. VSAT uses existing satellite broadcasting technology with higher powered components and antennas manufactured with higher precision than conventional satellite television systems. The satellite antenna at the customer's location includes, in addition to the receiver, a relatively high-powered transmitter that sends a signal back to the originating satellite. A very small portion of a transponder is used for each VSAT return path channel. Each VSAT terminal is assigned a frequency for the return path which it shares with other VSAT terminals using a shared transmission scheme such as time division multiple access.^[1]

An innovative feature of VSAT is that the technology has evolved to the point that something that previously could only be done with large, high-powered transmitting satellite dishes can now be done with a much smaller and vastly lower-powered antenna at the customer's premises. In addition, several return-path channels can co-exist on a single satellite transponder, and each of these return-path channels is further subdivided using to serve multiple customers.

In the system used by WildBlue, 31 different spot beams are used to serve the continental United States instead of the one beam used by conventional satellites.^[2] Thus, the same Ka-band transponders and frequencies are used for different regions throughout the United States, effectively re-using the same bandwidth in different regions.

The return path is transmitted from the customer's receiver in the L-band to a device called a low-noise block upconverter. There it is converted into the much higher frequency satellite transmission frequency, such as Ku-band and Ka-band, and amplified. Finally the signal is emitted to the dish antenna which focuses the signal into a beam that approximately covers the satellite with its beam. Because the transmission cannot be precise in these smaller dishes there is some effort to use frequencies for the uplink that are not used by adjacent satellites otherwise interference can occur to those other satellites.

Another satellite communications innovation, also used by satellite trucks for video transmission, is that only a small portion of a single satellite transponder is used by each VSAT channel. Previously a single transponder was required for a single customer but now several customers can use one transponder for the return path. This is in addition to time-based subdivision.

Pros and cons of VSAT networks

Advantages

• Availability: VSAT services can be deployed anywhere having a clear view of the Clarke Belt
• Diversity: VSAT provides a wireless link completely independent of the local terrestrial/wireline infrastructure - especially important for backup or disaster recovery services
• Deployability: VSAT services can be deployed in hours or even minutes (with auto-acquisition antennas)
• Homogeneity: VSAT enables customers to get the same speeds and service level agreements at all locations across their entire network regardless of location
• Acceleration: Most modern VSAT systems use onboard acceleration of protocols such as TCP ("spoofing" of acknowledgement packets) and HTTP (pre-fetching of recognized HTTP objects); this delivers high-quality Internet performance regardless of latency (see below)
• Multicast: Most current VSAT systems use a broadcast download scheme (such as DVB-S) which enables them to deliver the same content to tens or thousands of locations simultaneously at no additional cost
• Security: Corporate-grade VSAT networks are private layer-2 networks over the air

Disadvantages

• Latency: Since they relay signals off a satellite in geosynchronous orbit 22,300 miles above the Earth, VSAT links are subject to a minimum latency of approximately 500 milliseconds round-trip. This makes them a poor choice for "chatty" protocols or applications such as online gaming
• Encryption: The acceleration schemes used by most VSAT systems rely upon the ability to see a packet's source/destination and contents; packets encrypted via VPN defeat this acceleration and perform slower than other network traffic
• Environmental concerns: VSATs are subject to signal attenuation due to weather ("Rain Fade"); the effect is typically far less than that experienced by one-way TV systems (such as DirecTV, DISH Network or British Sky Broadcasting) that use smaller dishes, but is still a function of antenna size and transmitter power and frequency band
• Installation: VSAT services require an outdoor antenna installation with a clear view of the sky (southern sky if the location is in the northern hemisphere or northern sky if the location is in the southern hemisphere); this makes installation in skyscraper urban environments or locations where a customer does not have "roof rights" problematic

Future applications

Advances in technology have dramatically improved the price/performance equation of FSS (Fixed Service Satellite) over the past five years. New VSAT systems are coming online using Ka band technology that promise higher bandwidth rates for lower costs.

FSS satellite systems currently in orbit have a huge capacity with a relatively low price structure. FSS satellite systems provide various applications for subscribers, including: telephony, fax, television, high speed data communication services, Internet access, Satellite News Gathering (SNG), Digital Audio Broadcasting (DAB) and others. These systems are applicable for providing various high-quality services because they create efficient communication systems, both for residential and business users.

Constituent parts of a VSAT configuration

• Antenna
• Block upconverter (BUC)
• Low-noise block converter (LNB)
• Orthomode transducer (OMT)
• Interfacility Link Cable (IFL)
• Indoor unit (IDU)

All the outdoor parts on the dish are collectively called the ODU (Outdoor Unit), i.e. OMT to split signal between BUC and LNB. The IDU is effectively a Modem, usually with ethernet port and 2 x F-connectors for the coax to BUC(Transmit) and from LNB (Receive). The Astra2Connect has an all-in-one OMT/BUC/LNA that looks like a QUAD LNB in shape and size which mounts on a regular TV sat mount. As a consequence it is only 500mW compared with the normal 2W, thus is poorer in rain.

Training

Modern VSAT systems are a prime example of convergence, and hence require skills from both the RF and IP domains. VSAT specific training includes:

• ITC Global VSAT Career Certifications
• Global VSAT Forum VSAT Installer Certification

References

1. ^ http://www.comsys.co.uk/vsatnets.htm VSAT Network FAQ
2. ^ http://www.wildblue.com/aboutWildblue/how_it_works_demo.jsp WildBlue spot beaming

External links

• Satellite Internet and VSAT Information Centrum
• VSAT FAQ
• The Role of Satellite Comms in Remote Area Mining Operations
• ASTRA2Connect satellite Internet website

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