Introduction to PC Wireless Networking

Introduction

There are many ways that computers communicate with both each other and various other devices; wireless networking (not to be confused with wireless keyboards and mice) is just one of those ways. Wireless communication devies have greatly advanced over the last few years and are now very common in many households and businesses. 

Most wireless networks consist of two basic components: a wireless access point (most often a wireless router) and connected wireless devices (such as a computer, tablet, or WiFi-enabled phone). Most devices support multiple protocols to improve backward compatibility, but in order to support older devices a wireless network must run at the speeds supported by the oldest connected device. Unlike wired networks, the speed of a wireless network can fluctuate greatly depending on the supported speed of the hardware as well as many different environmental variables such as walls and interference from other devices. In this article, we will be covering the basics of PC wireless to give you the knowledge necessary to understand current wireless technology to help you get the most out of your wireless network.

This article is very lengthy, so feel free to skip ahead to any section that you are more interested in.

 

802.11 Protocols

Since the start of widespread adoption in 1999 the 802.11 standard has had four main protocols, many of which are still commonly found today. These standards are simply a set of guidelines that wireless manufactures have to follow in order to maintain compatability with other wireless devices.

Out of the four protocols above (802.11n is listed twice since it is available in both 2.4 GHz and 5 GHz variants), only 802.11a is rare to see. Slightly older networks or networks that need to support older devices will tend to use 802.11b or 802.11g, while newer networks tend to use 802.11n. One problem that causes quite a bit on confusion for those not familiar with wireless networking is the two variations of the 802.11n protocol. Within 802.11n, you can use either the 2.4 GHz or 5 GHz frequency, utilize either 20MHz or 40MHz of bandwidth (although 40MHz is limited to the 5Gz frequency only) and can use between 1 and 4 simultaneous data streams (MIMO streams) which makes it difficult to understand what you are getting and what you want to use. Depending on the number of MIMO streams and the bandwidth, the speeds of 802.11n can range between 72.2 Mbps to 600 Mbps. This gives a very wide range of expected speeds when using 802.11n that will depend on your wireless card, router, and the ambient environment. 

It's worth noting that at the time of this article, there are no wireless adapters that support true 600mbps transfer rates. There are cards that claim speeds of 600, 750, or even 900mbps, but when you actual get into the specs you will find that they cannot actually transmit data at those speeds. These devices are dual band adapters that essentially allow the device to connect to a network twice. The result is just like if you connect two ethernet cables to your PC as it theoretically doubles the amount of data that can be transferred between your computer and your network. While great in theory, this does bring about some complications that can cause the network to run at less than optimal speeds. Interference is a major issue with wireless networks, and because you are transmitting a lot of data at once over two separate wireless signals, the two signals can easily cause interference problems with each other resulting in performance degradation.

MIMO Streams

MIMO streams allows a wireless device to send and receive multiple data streams simultaneously. This is what allows 802.11n to be up to four times faster than 802.11g. MIMO streams can be utilized in one of two main ways. If only a single device needs to transfer data to your wireless access point, the device can use as many of the MIMO streams as it supports to transfer the data as fast as possible. MIMO streams can also be used to completely separate the data streams from two different wireless devices, allowing each to operate at the full speed available on that stream without interfering with each other.

Most wireless devices will self-manage this process to help keep the network running as smoothly and quickly as possible. Even if your computer does not support multiple MIMO streams, your network can still benefit from a wireless access point that supports multiple streams since the access point will automatically separate the connected wireless devices into separate MIMO streams. This allows each device to transfer data at the highest possible speed.

One common way to tell how many MIMO streams a device supports is to look at the number of antennas on the device. Each antenna usually represents a separate stream, so two antennas indicate the device supports two MIMO streams and three antennas indicate support for three MIMO streams. The only way to know for certain is to check the specifications of the device, but this is true for the majority of wireless devices.

If you want to know more about MIMO streams, we recommend reading the Wikpedia article on MIMO streams for more information.

2.4 GHz vs 5 GHz

Most wireless devices use one of two frequency bands: 2.4 GHz or 5 GHz. 2.4 GHz is by far the most common, but 5 GHz has been making a comeback in recent years. 5 GHz was first introduced in 1997 with the 802.11a protocol, but never gained traction due to its limited range. However, the transmitting power of wireless devices has improved in recent years, so it has been making somewhat of a comeback in recent years. There are three major points in which the performance of the 2.4 GHz and 5 GHz frequency bands can be compared: speed, interference and range.

Speed:
In terms of raw speed, 5 GHz is the easy winner. In the 802.11n protocol, the 40MHz bandwidth can only be used if the wireless device is operating at 5 GHz. Bandwidth directly affects speed, so twice the bandwidth means twice the theoretical speed. The 5 GHz band also has less interference, which additionaly results in higher speeds. Later in this article we will be looking at the real-world performance of both 2.4 and 5 GHz networks, but feel free to skip ahead if you want to view that data now.

Interference:
The 5 GHz band is currently very open, with few devices operating at this frequency. Since 5 GHz wireless networks are still fairly uncommon, it is unlikely that you will need to worry about a neighbor's wireless network causing interference. The 2.4 GHz band, on the other hand, is highly polluted. Not only wireless networks, but baby monitors, Bluetooth devices, and even microwaves operate within the 2.4 GHz band. Because of this, a network operating on the 5 GHz band will have far fewer interference problems, resulting in a more stable and consistent wireless network.

Theoretical Range:
In terms of speed and interference, the 5 GHz frequency easily beats the 2.4 GHz frequency, but the main problem with 5 GHz is range. As seen in the graphic below, the distance between each of the peaks and valleys of the 5 GHz wave is much closer than that of the 2.4 GHz wave form. This shape makes it much more likely to contact physical objects between the transmission and receiving locations, resulting in lower signal strength. Because of this, a 2.4 GHz wireless network will have a much greater range than a 5 GHz network.

Effects of Frequency on Range

We know that a 2.4 GHz wireless network should have a greater range than a 5 GHz network, but exactly how significant is this difference? To find out, we took signal strength readings throughout our office using a dual band router, which can transmit at both the 2.4 GHz and 5 GHz frequencies. By using a dual band router which can transmit on both the 2.4 GHz and 5 GHz frequency, we ensure that a difference in antenna or signal output power will not affect our results. Our readings were taken using the Puget M550i laptop from our Traverse Pro line using NetSurveyor.

 

 

 

 

 

 

Our office at Puget Systems has plenty of walls, a second floor, and a large open warehouse space. This gave us a great look at how the signal strength for a 2.4 GHz and 5 GHz network compare in various environments. We used a heatmap to display our findings because it provides an easy to read visual indication of signal strength. The wireless router was positioned on the first floor in the corner of our office (shown as a blue icon on the heatmap).

As you can see, the 2.4 GHz signal strength is much better throughout the office. Where the 2.4 GHz is able to provide >50% signal strength to most of the main office area (including most of the second floor) and >40% signal strength to even the farthest corners of the warehouse. Comparatively, the 5 GHz struggles to keep the signal strength above 50% after going through just a couple of walls. The amount of signal drop-off that occurred on the second floor with the 5 GHz frequency was a bit of a surprise to us. It shows very clearly that if you are in a building that needs wireless access on multiple floors, a 5 GHz wireless network is likely not the best choice.

What this information means is that in a typical 1-2 story house or apartment, the lower range of a 5 GHz network should work just fine. In an office environment where the distance between devices can be much larger, however, the longer range of a 2.4 GHz network may be a better choice.

What Affects Speed

As anyone who has used a wireless network can tell you, a wireless network will never run at the speed advertised by the hardware. Even in absolutely perfect conditions, the way that computers transmit data prevents you from achieving the full advertised speed.

Computers transmit data using packets which in addition to the raw data contain information including the source, the destination, protocol information, packet number, footer, and error correction data. Depending on the protocol type, this information can take up to 20% of the total packet size, resulting in roughly 80% data efficiency. So even if the wireless network is running at 300 Mbps, already the actual data transfer speed is closer to 240 Mbps. In addition to the sending and receiving of these data packets, there are also small "acknowledgement" packets that are sent to confirm that the data was transmitted successfully. These are not very large, but do slightly reduce the data transfer speeds. Lastly, all wireless devices send out a constant stream of "query" packets for basic network information including what networks are available, what the signal strength is, and what protocols are being used. Again, these packets are small, but very quickly add up.

In addition to the packet structure, the speed of your hardware, signal strength, and interference play a major role in the actual speed you should expect from a wireless network.

The speed of your hardware is the easiest to understand and is simply what your hardware is capable of at both your computer and your wireless access point and is a matter of the lowest common denominator. Even though your router can handle 300Mbps, if the wireless adapter in your computer can only handle 54Mbps you will be limited to 54Mbps.

Signal strength is simply how strong of a signal there is between your computer and your wireless access point. This can be affected by many things, but mostly by distance and physical objects such as walls. You can find the signal strength in Windows by a variety of different methods. The first method is to simply click on the Network icon in the taskbar which brings up a list of the available wireless networks and their approximate signal strength. To get a more accurate reading of the signal strength, simply run the command "netsh wlan show networks mode=Bssid" from a command line. This will output all the information Windows knows about the various wireless networks in range including the maximum speed and signal strength. 

Both of these methods do a decent job, but to get a very accurate look at signal strength, we recommend using a third part utility such as NetSurveyor. These programs are great for showing exactly what is going on with both your wireless network and other networks in your area.

The final impact on wireless speed is the amount of interference found in the area. This can be from a wide variety of sources including other wireless networks, cordless phones, baby monitors, Bluetooth devices, and even microwaves. Interference mostly comes into play in congested areas such as apartment complexes or college dorms where there are a large number of wireless networks operating at once. Beyond removing the devices causing the interference, the only way to lessen the effects of interference is to either change the channel your wireless devices operate on (which slightly alters the frequency being used) or to use a completely different frequency range. 2.4 GHz is the most commonly used frequency for wireless networks (which is why interference is sometimes a problem) but many newer devices can also operate at 5 GHz. Note that both your computer and wireless access point need to support operating at the 5 GHz frequency range in order to communicate with each other.

Signal strength and interference levels affect your wireless speed because they cause the wireless signal to be corrupted to the point that the receiving device can no longer read the data. When this happens, the sending device has to keep resending the same data over and over again until the receiving device is able to successfully read the data. Depending on how bad the signal strength and interference is, this can slow wireless transfer speeds to a crawl.

Advertised vs Real World Performance

To show how much signal strength and interference affects a wireless network; we ran a network performance benchmark (LAN Speed Test) over a 24 hour period using both the 2.4 GHz and 5 GHz frequencies at two different distances. While our office naturally has plenty of computers running, nearly all of them are shut down at night which will provide us with an environment that has both high and low levels of ambient interference.

 

 

 

 

 

 

Our testing was done using the 802.11n protocol with three MIMO streams giving us a maximum advertised speed of 216.6 Mbps at 2.4 GHz and 300 Mbps at 5 GHz. In order to reduce the number of variables in our testing, the network was configured without any encryption. We ran our testing from a distance of 10 ft. with a clear line of sight as well as from 65 ft. away (from one corner of the first floor of our office to the opposite corner on the second floor). This 65 ft. test goes through the ceiling/floor and at least 3 walls so it will be a very good indication of how both distance and physical obstacles affect wireless speeds. Here is a breakdown of the distances, obstacles, and resultant wireless signal strength:

As we showed earlier in this article, the 2.4 GHz has a much stronger signal over longer distances. Even at 10 feet with a clear line of sight, the 5 GHz network was already down to 60% signal strength. At 65 feet, the signal strength is down to 33% which will likely have a significant impact on performance. The question now is if the lower signal strength of the 5 GHz network or the higher interference on the 2.4 GHz network will cause a greater impact on network performance.

To report our findings, we graphed the results in two different ways. The first graph is simply a the raw speeds we saw over the 24 hour testing period. This results in quite a few spikes and dips in the results so in order to clear that out we applied a trendline in Excel using a 10 period moving average and saved the data to a second graph. Since we are very interested in how much interference affects transfer speeds, we also overlaid a graphic showing the number of employees that were present in the office during our testing period. This is not a perfect indication of interference levels since some employees have more devices running then others, but it at least gives us a general idea of interference levels.

Starting with the 2.4 GHz network, our results are very interesting. At only 10 feet away with a clear line of sight, we had an average write speed of about 66 Mbps (blue line) and a read speed of about 94 Mbps (red line). Remember that our advertised speed should be 216.6 Mbps, which we are clearly well short of. What is nice to see from the graphs is that the results were fairly consistent throughout the entire 24 hour testing period.

Our results at 65 feet through multiple walls, however, showed a huge fluctuation in read and write speeds. On average, we saw a write speed of about 17 Mbps (green line) and a read speed of about 63 Mbps (orange line). Over the course of our testing period we saw as much as a 50% drop in performance as the number of employees plateaued around 1pm. These are very intriguing results, and show very clearly how much both signal strength (as shown by the speeds around midnight) and interference (as shown by the speeds around 1pm) impacts wireless performance.

For our 5 GHz testing, we again saw the same spikes in performance, but oddly the spikes were much less pronounced at the longer 65 foot distance. At 10 feet with a clear line of sight, we had an average write speed of about 118 Mbps (blue line) and a read speed of about 122 Mbps (red line) which is significantly better than our results with the 2.4 GHz network, but still short of the advertised 300 Mbps.

As expected, the speeds were much lower at the longer 65 foot distance with an average write speed of about 19 Mbps (green line) and a read speed of about 60 Mbps (orange line). By some fluke, these speeds end up being almost identical to the overall average speed of the 2.4 GHz network at 65 feet. What is really interesting to see is that even at the long 65 foot distance, there was very little fluctuation in the results over the entire 24 hour period. This very clearly shows how much less interference there is when using a 5 GHz wireless network.

From these results, it is clear that even under the most ideal circumstances you will never see speeds matching the advertised 216.6 Mbps or 300 Mbps. To give us one final point of view of our results, we graphed our overall average results and calculated the percentage difference between our measured results and the advertised speeds. Note that this is the overall average, so the results from the 2.4 GHz network at 65 feet are a bit skewed due to the amount of variance over the 24 hour testing period.

So what can we conclude from our testing? It is almost impossible to estimate the speeds you should expect to see in the real world due to all the variables, but we can pretty confidently say that you should never expect to see speeds much greater than 40% of the advertised network speed. As the distance and interference levels rise, this can easily be reduced to as low as 10% of the advertised speeds. Also, 5 GHz networks are indeed faster than 2.4 GHz networks, but have a greater drop off in performance over longer distances. Lastly, 2.4 Ghz networks are much more susceptible to interference than a 5 GHz network so if you are in a heavily populated area, a 5 GHz network is probably a better choice than a 2.4 GHz network.

General Tips for Improving Performance

So what can you do if you want to get more speed out of your wireless network? The easiest thing to do would be to upgrade the hardware of your wireless access point and the hardware in your computer/laptop. If that is not an option, there are still a few things you can do to reduce interference and improve signal strength.

Place the wireless access point as close to the wireless devices as possible
This may seem like common sense, but simply having the wireless AP close to your devices can be one of the biggest things you can do to help improve signal strength and reduce interference. This doesn't actually reduce interference in any way, but since the signal strength will be stronger, the ambient "noise" will not affect your network as much.

Keep the wireless AP away from other electronic devices
The closer your wireless AP is to other devices, the more likely interference will become a problem. Common electronic devices to avoid are: microwaves, televisions and computers.

Use the less common 5 GHz frequency band
This will only work if all of your devices support operating at the 5 GHz frequency, but if you can use it, the level of interference should be much, much less than the often cluttered 2.4 GHz band. 5 GHz is also typically much faster, but the range is greatly reduced. In a small home or apartment, however, range may not be as important a factor as reducing the level of ambient interference.

Upgrade the firmware and drivers
Manufactures often have newer firmware or drivers for wireless access points than what comes with the device. Ensuring you are using the latest of both can often improve both the stability and speeds of your wireless network.

Understanding Wireless Channels

Within either the 2.4 or 5 GHz frequency band, there are a number of channels available for use. Channels are essentially a way to fine-tune which part of the wireless band you are using to give you some fine control over the exact frequency you want to use. Adjusting the wireless channel allows you to slightly alter the frequency used, effectively lessening the effects of some of the local interference.

Within the 2.4 GHz frequency range, there are a total of 14 available channels, although channels 12, 13, and 14 are not allowed for use in wireless networks by the FCC.

Each channel is 22 MHz wide, but is only spaced 5 MHz apart which means there is a great deal of overlap between the channels. In the USA, the best channels to use typically are channels 1, 6 or 11, although some research must be done to determine the optimal channel for your wireless network. The easiest way to determine what channels are in heavy use in your area is to use a program such as NetSurveyor. Simply install the program on your wireless-enabled computer, switch to the "Channel Usage" tab and compare the channels being used.

Ideally, you want the channel of your wireless network to be separated from other active channels by at least 3 inactive channels to reduce the amount of overlap. If this is not possible, the best course of action is to use the channel that has the least amount of activity on the neighboring channels. In the image below, there are many wireless networks using a variety of channels, but they are concentrated in channels 1, 6 and 11. In this instance, channel 2 would be the best channel to use since according to the previous graphic showing the channel widths, using channel 2 will completely miss the large amount of traffic broadcasting on channel 6. There will be some overlap with channel 1, but there is far less traffic on that channel than on channel 6 so that overlap is much more acceptable.

While wireless adapters will automatically select the appropriate channel to use, they are often not very smart about it so manually researching the optimal channel and setting it on your wireless access point will often bring about much better results. By manually determining the local channel traffic patterns you can optimize your network to reduce the amount of interference as much as possible. Note that programs such as NetSurveyor can only tell you the amount of traffic on specific channels at the exact moment the program is running. To get a clear idea of the how the patterns shift over time, you will want to run the program at the time that you normally use your network. For example, if you only use your wireless network from 6-10pm, you only need to be conscerned about that period of time. It does not matter if your neighbor saturates the same channel you use at noon every day, since that is not when you will be accessing your network.

Changing your wireless channel is different for every access point, so please refer to the documentation for your wireless access point for detailed instructions on how to manually set the channel.

Upgrading Wireless Antenna

While not true for all devices, many have removable and thus upgradeable antennas. There are a number of antenna types (which we will cover in the next section), each with distinct advantages and disadvantages. However, the one thing that is true for all antennas is that when it comes to physical size, bigger is definitely better.

Upgrading the antenna on a capable device is simply a matter of unscrewing the stock antenna and screwing on the replacement antenna. One very important thing to note is that if you are only trying to achieve higher signal strength, you will want to upgrade the antennas on both the wireless AP and the receiving devices. If interference is at all a problem, however, you generally only want to upgrade the antenna on the wireless AP and not the receiving device. The reason for this is that it allows the signal from the wireless AP to be stronger which can potentially drown out any other ambient signals that are causing interference. If the antenna on the receiving device is also upgraded, you will further improve the signal strength from your wireless AP, but also from every other wireless device in range. 

Now, this works both ways, but since download speeds are generally more important to users than upload speeds, upgrading the antenna on just the wireless AP is generally the best course of action. If for some reason upload speed is more important than download speed, then you would want to upgrade the antennas on the receiving device rather than on the wireless AP.

Wireless Antenna Types

Wireless antennas come in a wide variety of types, sizes, and strengths, but the majority of PC wireless antennas boil down to two main categories: Omni-directional and Semi-directional antennas. As the names imply, Omni-directional antennas send signals in all directions, while a Semi-directional antenna send signals in a shape resembling a cone.

For most wireless networks, Omni-directional antennas are the ones you will want to use since they require much less fine-tuning in order to function properly. Signal strength tends to be higher with Semi-directional antennas since the signal is more narrowly focused, but they require you to have them correctly oriented facing the receiving wireless device. This make Semi-directional antennas good for a wireless network when the receiving devices are clustered together and are far from the wireless access point, but not so great when the receiving devices are spread out over a large area.

In addition to the type of the antenna, the key differentiation between antennas is the gain, which is typically reported in dBi. The higher the gain of the antenna, the stronger the signal it can send and the weaker the signal it can receive. In terms of PC wireless, a higher gain antenna should always give you much better signal strength within your wireless network.

It's worth noting that even Omni-directional antennas do not send signals in a perfect sphere. Every antenna is slightly different, and each will have certain areas in which the signal is either stronger or weaker. This variance in signal strength is referred to as the radiation pattern of the antenna and is generally shown by a pair of diagrams depicting the pattern on both a horizontal plane (also called a Azimuth Plane Pattern) and vertical plane (also called an Elevation Plane Pattern).

Understanding Radiation Patterns

Antenna radiation patterns are not a direct indication of signal strength, but rather a visualization of the direction in which the antenna transmits and receives signals at a specific level. Because of this, the scale of the pattern is completely irrelevant. In the next section, you will see that the 2dBi and 9dBi antennas have the same horizontal scale even though the 9dBi antenna is much, much stronger. Antenna radiation patterns can basically be thought of as an ever-expanding shape where the current scale indicates the areas where the signal strength should be the same. Of course, this is an ideal pattern so physical objects such as walls can distort the radiation pattern.

To help give a clear idea of radiation patterns and how they change as the gain of the antenna goes up, we created 3D models of the radiation pattern in addition to the horizontal and vertical plane charts. Note that the 3D models are somewhat simplified so some of the very fine nuances of the radiation pattern may have been lost. Within the 3D model is a small red object which represents the physical antenna (not to scale). 

With that said, let's take a look at the relatively simple radiation pattern for a Cisco AIR-ANT2422DW-R 2dBi Omni-directional antenna: 

Since this is an Omni-directional antenna, the signal strength on the horizontal plane is consistent in every direction. On the vertical plane, however, the radiation pattern takes on a shape resembling two circles smashed together. Note that at the top (0°) and bottom (180°), the shape of the radiation pattern is bent towards the origin. This means that directly above and below the antenna there is an area where the signal strength is at sub-optimal levels. Since the dip in the top of the pattern only goes about halfway to the origin, the signal strength above the antenna, while greatly reduced, is still at useable levels. The dip at the bottom, however, goes almost all the way to the origin indicating that directly below the antenna there will be a small area with almost no signal propagation.

In the real world, this means that you will want to avoid having any devices directly above and below the antenna. Most antennas are designed to be able to point in nearly any direction, so if you do have a device directly above or below the antenna, you simply need to reposition the antenna so that the device is covered in one of the higher signal areas as shown in the radiation pattern.

If you would like a more in-depth and technical understanding of antenna radiation patterns, we recommend reading Cisco's Antenna Patterns and Their Meaning article.

Antenna Radiation Patterns

For our antenna selection, we decided to exclusively use Cisco models since Cisco has a wide variety of antennas, all with manufacture-published radiation patterns. Our thought process in choosing specific antennas was simply to look for consistency in the radiation pattern compared to other antennas of the same type and power.

Omni-Directional

Omni-directional antennas transmit in all directions, so the near identical patterns on the horizontal planes are completely expected. One very important detail on the vertical plane is that the higher the gain of the antenna, the more complex the radiation pattern becomes. The 2dBi antenna has a very smooth, mostly round shape on the vertical plane while the 9dBi antenna has a very complex pattern with lots of low and high areas. In general, however, we can take from these patterns that Omni-directional antennas work best on a horizontal plane.

So if you have two devices with Omni-directional antennas, it is best to have the antennas parallel to each other (not pointing tip to tip) so that the high signal areas overlap.

Semi-Directional

Unlike Omni-directional antennas, Semi-directional antennas are largely used to project a signal in one primary direction. There is some signal propagation above, below, and behind Semi-directional antennas, but the majority of the signal is directly in front of the antenna. Note that the radiation patterns for this type of antenna are not affected as much as the dBi goes higher. The only direction that has a low signal area is directly behind the antenna, but since these antennas are intended to point directly at a device is not much of an issue.

Real World Antenna Performance

While radiation patterns are great for showing how and why you should orient antennas properly, they do not show the actual real world difference the gain of an antenna has on signal strength. To find this out, we again used a Puget M550i laptop and a wireless router to take multiple signal strength readings throughout out office. Unlike our previous testing, we will be using an Asus router since it has removable antennas which will allow us to test three different antennas.

 

 

 

 

 

 

 

 

 

Our office at Puget Systems has plenty of walls, a second floor, as well as a large open warehouse space. This should give us a great look at how the signal strengths of each of our three antennas compare in various environments. The wireless router was positioned on the first floor in the corner of our office (shown as a blue icon on the heatmap). To record the signal strength, we used the third part utility NetSurveyor.

On the first floor, the 9dBi antenna provides about 8% better signal strength than the generic 2dBi antenna. This may not seem like much, but it is essentially the difference between a useable and non-useable wireless network at the far end of our warehouse. The 5dBi semi-directional antenna performed only about 2% better than the generic 2dBi antenna, and luckily the cone shape did not result in any low-signal areas.

The results of the second floor are a bit interesting. Instead of the 8% better signal strength we saw when using the 9dBi antenna, the average signal strength was only 3% better on the second floor. The 5dBi Semi-directional antenna, however, still had the same 2% better signal that we saw on the first floor.

What does this data mean? Basically, it confirms that higher dBi antennas do provide a better signal strength, but the increase might not be as much as expected. It is definitely worth upgrading your antennas if possible, but upgrading antennas will likely only result in a moderate boost in wireless performance.

Frequently Asked Questions

I have a wireless keyboard/mouse; do I need a wireless card?

No, you do not. Wireless keyboard and mice do not use the same wireless technology as wireless networking and come with their own USB adapter that needs to be plugged into the computer. Some keyboard and mice use Bluetooth and some use infared signals, it all depends on your exact model of keybaord and mouse.

What is the difference between Wi-Fi and Bluetooth?

While both Wi-Fi and Bluetooth are wireless networking standards, they are used for two completely different tasks. Wi-Fi is used to connect computers and some shared devices (such as printers, network attached storage, etc.) to both each other and to the internet. Bluetooth is primarily used to connect single-system peripheral devices such as keyboards, mice and headsets to a computer.

What kind of security should I use with my wireless network?

There are three main wireless security protocols (commonly referred to as wireless encryption): WEP, WPA and WPA2. Out of the three, WEP should be avoided whenever possible due to its lower level of security. WPA and WPA2 are both relatively secure, although WPA2 is a bit better from a security standpoint. WPA2 does require a hotfix in order to work with Windows XP, however, so it may not be the best choice for all wireless networks. 

Is a wireless network or a wired network faster?

In general, a wired network will be faster and more stable than a wireless network. The main advantage of wireless networking is mobility and the lack of physical wires.

How many devices can be on a wireless network?

While the exact number of devices will vary based on the hardware, most home or business users will never run into a physical limit. The more devices on a network, however, the slower the network will run. Even through there are no physical wires, a wireless access point can still only handle a certain amount of data at a time.