The single most important thing you can do to extend the range of your 802.11 system is to install an external antenna with some good gain and directional or omni-directional qualities. WiFi is simply a radio, which is used for computer. You can think of your antenna as the “speaker system” of your WiFi card. Get a bigger antenna; your WiFi will go a lot further. However, don’t install a speaker on your wifi system or your range will be horrible!

Directional Antennas
Directional antennas are used for Point-to-Point or sometimes for Multi-Point systems depending on the setup. If you are trying to go from one location (say for instance your router), to another location, this is the type of antenna we recommend. Directional antennas are Backfires, Yagi, Panel and dish type antennas.

Omni-Directional
This is the common “Base” antenna used for Point-to-Multi-Point or can be an omni-directional antenna for your car. An Omni-Directional antenna would serve as your main antenna to distribute the signal to other computers or devices (such as wireless printers, PDAs, etc) in your workgroup. You can use 2 Omni-Directional antennas for a point to point system, but this is usually not recommended because there is no real point to distributing your signal all over the place when you only want to going from point A to point B. Please refer to Directional antennas above. Typical Omni-Directional WiFi antennas consist of Vertical Omnis, Ceiling Domes, Rubber ducks, Small Desktops and Mobile vertical antennas.

Point-to-Point
Point-to-Point systems usually involve 2 different wireless points, or building to building wireless connections. But there are exceptions to every rule. If the access point is across a long valley and the owner of the system wishes to share the connection with multiple users on the other side of the valley. This would be a point to Multi-Point system but using directional antennas.

Point to Multi-Point
Point to Multi-Point systems is usually for sharing a WLAN (Wireless Local Area Network) or a high-speed internet connection inside of your home or with neighbors (oops, we didn’t say that). They can also be for WAP (Wireless Access Points) such as you find at local coffee shops, truck stops, airports, RV parks and the ever expanding list of WAPs becoming available. Traveling with a notebook computer is extremely fun and can be a great business tool for the frequent traveler.

Range
The range of the signal will depend on several factors, including power output of your wireless card or router, receive strength of the wireless card or cards you are transmitting to, obstructions buildings or trees which may be in the way of your transmitting path, walls, etc. Since there are so many factors which can determine the overall range of your wireless system, it is impossible to cover it in this simple article. A rule of thumb however is to always choose an antenna which you think may be overkill. Why? Because the power output is extremely small it is necessary to have as much gain as possible. Most wireless cards have a power output of 32 milliwatts (+15dBm), which is roughly the same amount of power it takes to light a high power LED (Light Emitting Diode). LEDs are bright, but imaging trying to see one at a large distance or through a building or trees. This is why the antenna is critical for amplifying that signal so it is as strong as possible. Why is the power output so small? Because 802.11 works at the same frequency as a microwave oven (2.4 GHz) and if it put out a large amount of power…. well, enough said. Microwave popcorn! If you are somewhat technical, please visit our online wifi range calculator to learn more.

There are many uses for wireless applications, either in a home, office or rural situations. Let’s examine each of these applications.

Home
Home antennas are always the easiest types of antennas to purchase and take the least amount of effort in choosing and installing. In most circumstances, only one antenna is needed on the remote computer. We recommend putting any external antenna on the remote computer, simply because if you install it on your router and don’t plan on setting up security, it will provide less signal strength outside of your home and your system will be less prone to hackers. If you have a multi-story home or a very large house, you may have to install antennas on every computer to get the range or bandwidth required. Every wall that you have to penetrate will decrease the signal strength of your system. For the best signal strength and signal, we recommend installing a 5dB ceiling dome antenna and either wireless desktop antennas or RL-1000 antennas on all remote computers. It is best to start with 1 antenna on a remote computer and test the signal strength and range.

Office
Office antennas are pretty straight forward. If you want to run a network system inside of your office building and don’t want to run cables all over the place, first, purchase a good wireless card, install a Ceiling Dome, Desktop or Wibberduck antenna to extend and maximize the signal to your office router. It’s that simple. However, this can get a little complex if the office is split between 2 different points or if the office is really large or on multiple stories of a building.

Mobile WiFi antennas
Why would anyone want WiFi in their car? Well, there are a lot of truck-stops and RV parks around the country now that offer wireless access. In fact, many public high speed wireless networks can be accessed directly from your car, truck, or RV. There is also something called WarDriving which is where bad people drive around neighborhoods and get their high-speed access for free. We don’t condone this, but if you want to read more about it, please go to www.wardriving.com. It’s fun and entertaining reading.

Yagi Antennas
Yagi antennas were the design of two Japanese people, Hidetsugu Yagi and Shintaro Uda, and are sometimes referred to as Yagi-Uda antennas. They were originally designed for radio, but are now also used for 802.11 systems. These antennas are typically very directional and are used for point to point, or to extend the range of a point to multi-point system. We highly recommend using the RadioLabs 14 or 16 element weatherproof Yagi antenna if you want to install your system outside. They have excellent signal strength and in the right circumstances can communicate for miles!

Backfire antennas – The backfire is a small directional antenna with excellent gain. They look similar to a parabolic dish, but the gain isn’t as high. We highly recommend Backfire antennas for point to point or point to multipoint systems because of the excellent gain and the good noise figures. We offer a backfire antenna with 15 dBi of Gain!! This is excellent considering the antenna is only 10 inches diameter. Almost invisible!!

Parabolic or dish antennas
This is where the real power is! Parabolic dish antennas put out tremendous gain but are a little hard to point and make a connection with. As the gain of an antenna increases, the antenna’s radiation pattern decreases until you have a very little window to point or aim your dish correctly. Dish antennas are almost always used for a point to point system for long haul systems. The Parabolic Dish antennas work by focusing the power to a central point and beaming the radio’s signal to a specific area, kind of like the adjustable reflector on a flashlight. These antennas are highly focused and are the perfect tool if you want to send your signal a very long distance. To calculate the distance of your WiFi

Gain Considerations
The gain you will require for each individual WiFi antenna system will dependant on any direct objects in your path, the distance you must cover and the individual wifi cards. These all must be taken into consideration before choosing the proper antenna system. If our calculator is too difficult to use, please feel free to contact us for information.

Interference
As with all radio systems, interference is always a problem. If you are listening to an AM radio and you hear static, this is interference. The same thing applies to WiFi systems, however not to such a large degree. Things that cause interference with WiFi systems are Microwave ovens, certain lighting systems, other 802.11 access points or systems, microwave transmitters, even high speed processors for computers can cause interference for 802.11 systems. All these problems must be isolated before you can expect any significant range out of your system. If you need help, please don’t be afraid to ask us. Afterall, WiFi is our business.

4 steps to set up your home wireless network

You can use a wireless network to share Internet access, files, printers, and more. Or you can use it to surf the Web while you’re sitting on your couch or in your yard. Plus, it’s easier to install than you think.

There are 4 steps to creating a wireless network:

For Windows XP users, Windows XP Service Pack 2 is not required for wireless networking, but it does make things much easier. Service Pack 2 also helps protect you against hackers, worms, and other Internet intruders.

1.Choose your wireless equipment

The first step is to make sure that you have the equipment you need. As you’re looking for products in stores or on the Internet, you might notice that you can choose equipment that supports three different wireless networking technologies: 802.11a, 802.11b, and 802.11g. We recommend 802.11g, because it offers excellent performance and is compatible with almost everything.

A wireless router

The router converts the signals coming across your Internet connection into a wireless broadcast, sort of like a cordless phone base station. Be sure to get a wireless router, and not a wireless access point.

A wireless network adapter

Network adapters wirelessly connect your computer to your wireless router. If you have a newer computer you may already have wireless capabilities built in. If this is the case, then you will not need a wireless network adapter. If you need to purchase an adapter for a desktop computer, buy a USB wireless network adapter. If you have a laptop, buy a PC card-based network adapter. Make sure that you have one adapter for every computer on your network.

Note: To make setup easy, choose a network adapter made by the same vendor that made your wireless router. For example, if you find a good price on a Linksys router, choose a Linksys network adapter to go with it. To make shopping even easier, buy a bundle, such as those available from D-Link, Netgear, Linksys, Microsoft, and Buffalo. If you have a desktop computer, make sure that you have an available USB port to plug the wireless network adapter into. If you don’t have any open USB ports, buy a hub to add additional ports.

2.Connect your wireless router

Since you’ll be temporarily disconnected from the Internet, print these instructions before you go any further.

First, locate your cable modem or DSL modem and unplug it to turn it off.

Next, connect your wireless router to your modem. Your modem should stay connected directly to the Internet. Later, after you’ve hooked everything up, your computer will wirelessly connect to your router, and the router will send communications through your modem to the Internet.

Next, connect your router to your modem:

Note: The instructions below apply to a Linksys wireless router. The ports on your router may be labeled differently, and the images may look different on your router. Check the documentation that came with your equipment for additional assistance.

If you currently have your computer connected directly to your modem: Unplug the network cable from the back of your computer, and plug it into the port labeled Internet, WAN, or WLAN on the back of your router.

If you do not currently have a computer connected to the Internet: Plug one end of a network cable (included with your router) into your modem, and plug the other end of the network cable into the Internet, WAN, or WLAN port on your wireless router.

If you currently have your computer connected to a router: Unplug the network cable connected to the Internet, WAN, or WLAN port from your current router, and plug this end of the cable into the Internet, WAN, or WLAN port on your wireless router. Then, unplug any other network cables, and plug them into the available ports on your wireless router. You no longer need your original router, because your new wireless router replaces it.

Driver problems

Since Windows Vista’s launch, the drivers have been a big issue. Lots of hardware components (old and new) had no drivers for Windows Vista or, even if they had, their quality was very poor. One of the most prominent examples is Nvidia. When the GeForce 8800 graphic cards were launched, they were labeled as “Designed for Windows Vista”. It is only natural that many people asumed the graphic cards would work well with this operating system. Unfortunately that was not the case, as the Nvidia drivers had lots of issues. There were numerous posts on Nvidia’s official forums commeting the bad state of the drivers. Some users even built internet pages such as nvidiaclassaction.info to gather evidence for a class action suit.
Since then, Nvidia worked hard on the Windows Vista drivers and released many new and improved versions. However, their latest driver – Forceware version 158.24 – still has plenty of issues. For example, popular games such as World of Warcraft have low frame rates while others crash during play or have corrupted textures.

Nvidia is not the only company that has these issues. Other big hardware manufacturers such as Creative, renown for their sound cards and sound systems, have similar problems. When Windows Vista was launched, their drivers were mostly in beta stages. Even though they released so called “final versions”, their drivers had plenty of issues. Lots of users complained on the official forums and, after a while, Creative announced the ALchemy Project – a project that aims to offer complete DirectSound3D support for Sound Blaster X-Fi products in Windows Vista. Unfortunately, old sound cards such as the Audigy 2 series are not yet supported. Due to lots of users’ request, they started the development of ALchemy for Audigy sound cards. However, according to Creative, this products will be offered as a “low-cost” upgrade.

Having bad drivers is always better than having no drivers. Even today there are companies that do not offer Windows Vista compatible drivers for their hardware. For example, Mustek – a company famous for their scanning solutions, has still no drivers ready, not even in beta stages. Since the launch of Windows Vista and until today their driver download page has remained unchanged. The only thing they bothered to do was to state that “Currently we don’t provide drivers or updates for Windows Vista”. They have no forums and when we sent an e-mail asking for some feedback regarding Windows Vista drivers we received no answer.

Unfortunately Mustek is not the only example. There are other companies doing the same thing and lots of customers suffer.

Application compatibility

Drivers are not the only problem. Lots of applications do not work either on the new Microsoft operating system. That’s because many software developers created applications that function only if the user has full administrative privileges. With the introduction of UAC (User Access Control) and other system changes, lots of old applications have problems. The most prominent example of an application that was incompatible with Windows Vista is iTunes. Whenever the Windows Vista “Safely Remove Hardware” feature was used, it corrupted the user’s iPods, requiring a full restore. Also, iTunes text and graphics had display issues with Windows Vista. However, upgrading to iTunes v7.2 or higher solves these issues.

Lots of other applications had or still have problems. Most of these problems are encountered with applications that install legacy drivers in order to function. These applications can be CD/DVD burning utilities, VPN applications, virtualization solutions or even security suites. Other applications just refuse to install even though they could work on Windows Vista. This problem is due to the poor design of their installer. For example, some applications ask for the installation of Microsoft.NET Framework version 1.1 or 2.0. They won’t install even though Windows Vista has a newer version of .NET Framework.

Conclusion

Just like with any other new operating system, problems are inherent. What matters most is that both hardware manufacturers and software developers act in a proactive way and offer the required support to their customers in a timely manner. Unfortunately, Windows Vista’s launch revealed many problems even though Microsoft released it to computer hardware and software manufacturers, business customers, and retail channels, months before it was released worldwide to the general public.

Hopefully, both computer hardware and software manufacturers will fix their issues as soon as possible. And, maybe, they will learn from their mistakes so history won’t repeat itself with every new release of a major operating system.

Application Servers

Sometimes referred to as a type of middleware, application servers occupy a large chunk of computing territory between database servers and the end user, and they often connect the two.

Middleware is a software that connects two otherwise separate applications For example, there are a number of middleware products that link a database system to a Web server This allows users to request data from the database using forms displayed on a Web browser and it enables the Web server to return dynamic Web pages based on the user’s requests and profile.

The term middleware is used to describe separate products that serve as the glue between two applications. It is, therefore, distinct from import and export features that may be built into one of the applications. Middleware is sometimes called plumbing because it connects two sides of an application and passes data between them. Common middleware categories include:

* TP monitors
* DCE environments
* RPC systems
* Object Request Brokers (ORBs)
* Database access systems
* Message Passing

Audio/Video Servers

Audio/Video servers bring multimedia capabilities to Web sites by enabling them to broadcast streaming multimedia content. Streaming is a technique for transferring data such that it can be processed as a steady and continuous stream. Streaming technologies are becoming increasingly important with the growth of the Internet because most users do not have fast enough access to download large multimedia files quickly. With streaming, the client browser or plug-in can starts displaying the data before the entire file has been transmitted.

For streaming to work, the client side receiving the data must be able to collect the data and send it as a steady stream to the application that is processing the data and converting it to sound or pictures. This means that if the streaming client receives the data more quickly than required, it needs to save the excess data in a buffer If the data doesn’t come quickly enough, however, the presentation of the data will not be smooth.

There are a number of competing streaming technologies emerging. For audio data on the Internet, the de facto standard is Progressive Network’s RealAudio.

Chat Servers

Chat servers enable a large number of users to exchange information in an environment similar to Internet newsgroups that offer real-time discussion capabilities. Real time means occurring immediately. The term is used to describe a number of different computer features. For example, real-time operating systems are systems that respond to input > immediately. They are used for such tasks as navigation, in which the computer must react to a steady flow of new information without interruption. Most general-purpose operating systems are not real-time because they can take a few seconds, or even minutes, to react.

Real time can also refer to events simulated by a computer at the same speed that they would occur in real life. In graphics animation, for example, a real-time program would display objects moving across the screen at the same speed that they would actually move.

Fax Servers

A fax server is an ideal solution for organizations looking to reduce incoming and outgoing telephone resources but that need to fax actual documents.

FTP Servers

One of the oldest of the Internet services, File Transfer Protocol makes it possible to move one or more files securely between computers while providing file security and organization as well as transfer control.

Groupware Servers

A GroupWare server is software designed to enable users to collaborate, regardless of location, via the Internet or a corporate Intranet and to work together in a virtual atmosphere.

IRC Servers

An option for those seeking real-time capabilities, Internet Relay Chat consists of various separate networks (or “nets”) of servers that allow users to connect to each other via an IRC network.

List Servers

List servers offer a way to better manage mailing lists, whether they are interactive discussions open to the public or one-way lists that deliver announcements, newsletters, or advertising.

Mail Servers

Almost as ubiquitous and crucial as Web servers, mail servers move and store mail over corporate networks via LANs and WANs and across the Internet.

News Servers

News servers act as a distribution and delivery source for the thousands of public news groups currently accessible over the USENET news network. USENET is a worldwide bulletin board system that can be accessed through the Internet or through many online services The USENET contains more than 14,000 forums called newsgroups that cover every imaginable interest group. It is used daily by millions of people around the world.

Proxy Servers

Proxy servers sit between a client program typically a Web browser and an external server (typically another server on the Web) to filter requests, improve performance, and share connections.

Telnet Servers

A Telnet server enables users to log on to a host computer and perform tasks as if they’re working on the remote computer itself.

Web Servers

At its core, a Web server serves static content to a Web browser by loading a file from a disk and serving it across the network to a user’s Web browser. The browser and server talking to each other using HTTP mediate this entire exchange.

Grid computing (or the use of a computational grid) is applying the resources of many computers in a network to a single problem at the same time – usually to a scientific or technical problem that requires a great number of computer processing cycles or access to large amounts of data. A well-known example of grid computing in the public domain is the ongoing SETI (Search for Extraterrestrial Intelligence) @Home project in which thousands of people are sharing the unused processor cycles of their PCs in the vast search for signs of “rational” signals from outer space. According to John Patrick, IBM’s vice-president for Internet strategies, “the next big thing will be grid computing.”Grid computing requires the use of software that can divide and farm out pieces of a program to as many as several thousand computers. Grid computing can be thought of as distributed and large-scale cluster computing and as a form of network-distributed parallel processing. It can be confined to the network of computer workstations within a corporation or it can be a public collaboration (in which case it is also sometimes known as a form of peer-to-peer computing).

A number of corporations, professional groups, university consortiums, and other groups have developed or are developing frameworks and software for managing grid computing projects. The European Community (EU) is sponsoring a project for a grid for high-energy physics, earth observation, and biology applications. In the United States, the National Technology Grid is prototyping a computational grid for infrastructure and an access grid for people. Sun Microsystems offers Grid Engine software. Described as a distributed resource management (DRM) tool, Grid Engine allows engineers at companies like Sony and Synopsys to pool the computer cycles on up to 80 workstations at a time. (At this scale, grid computing can be seen as a more extreme case of load balancing.)

Grid computing appears to be a promising trend for three reasons: (1) its ability to make more cost-effective use of a given amount of computer resources, (2) as a way to solve problems that can’t be approached without an enormous amount of computing power, and (3) because it suggests that the resources of many computers can be cooperatively and perhaps synergistically harnessed and managed as a collaboration toward a common objective. In some grid computing systems, the computers may collaborate rather than being directed by one managing computer. One likely area for the use of grid computing will be pervasive computing applications – those in which computers pervade our environment without our necessary awareness.

DISTRIBUTED DENIAL OF SERVICE (DDOS)

Short for denial-of-service attack, a type of attack on a network that is designed to bring the network to its knees by flooding it with useless traffic. Many DoS attacks, such as the Ping of Death and Teardrop attacks, exploit limitations in the TCP/IP protocols. For all known DoS attacks, there are software fixes that system administrators can install to limit the damage caused by the attacks. But, like viruses, new DoS attacks are constantly being dreamed up by hackers.

What is a Distributed Denial of Service (DDoS) attack?

Have you ever tried to make a telephone call but couldn’t because all the telephone circuits were busy? This may happen on a major holiday and often happens on Mother’s Day. In fact, in the United States, telephone companies used to air commercials on television and radio that suggested you avoid peak calling times by making your calls early or late in the day.

The reason you couldn’t get through is because the telephone system is designed to handle a limited number of calls at a time. That limit was determined by weighing the cost of having all calls get through all the time with the amount of traffic the system receives. If the total number of calls is always high, it makes economic sense for the telephone company to provide more capacity to match that demand. However, if the number of calls is low compared to the holiday peaks, then the telephone company will build networks that accommodate only the lower off-peak number of callers and advise their customers to avoid peak calling times. It’s a basic matter of supply and demand.

Imagine that an intruder wanted to attack the telephone system and make the system unusable by telephone customers. How would they do this? One way would be to make call after call in an attempt to make all circuits busy. This type of attack is called a denial of service, or DoS, attack. In essence, the intruder has caused the telephone system to deny service to its customers. It is not likely that one caller working alone can tie up all telephone circuits. To do that would require making as many calls as possible from as many telephones as possible.