Extending wireless range

Hi:
My network has a wired desktop and two wireless notebooks (one is 11b; the other 11 b/g). Current range and speed are decent, but I'd like to extend the wireless range by about 75-100 feet.

The router must stay in the basement, but I'd like wireless connectivity beyond where it already reaches on the floor above. [ ]

Would upgrading from a DLink 514 router (802.11b) to DLink AirPlus Xtreme G DI 624 (11g) make any difference? If not,

How about combining the DI 624 with the DLink Wireless Range Extender (DWL-G800AP)? This can act as both an AP and repeater, but it will only repeat the signals of the DI 624 router.

Should I try upgrading the router first, or go for both?

Thanks,
Cpt. Hastings

 

Yeah, I would try using a High-Gain Antenna to extend your coverage. Maybe a wireless bridge could be added to the mix too.

 

Changing the router won't make a difference, I would go for the repeater or find a way to get your router to a higher floor, being in the basement is going to cut the distance big time as the antenna does not do well straight up. Oh you might try changing the orientation of the antenna.

Jack

The color of justice in america is green.
http://pbase.com/joneill

 

abaxter is right. An antenna is the easiest way to add significant signal. But there are a few other considerations. Let's discuss it a bit and I think it might help you better understand your options.

First, broadcast signals are measured in decibels - that same rating system used for sound. Decibels is a logarithmic scale so every time you add roughly 3 decibels, you double the power. 10 extra decibels = 10x the power.

Equipment broadcasts in milliwatts (mw) but that can be converted to decibels for more effective comparisons. Most cards broacast with 11 - 55mw (with about 20 being most typical). Access Points broadcast from 50 - 300 milliwatts with 100mw being by far the most common. You can lookup the specs on several models HERE.

Remember decibels is a logarithmic scale, so...

1000 mw = 30 dBm
300 mw = 25 dBm
200 mw = 23 dBm
100 mw = 20 dBm
75 mw = 19 dBm
50 mw = 17 dBm
20 mw = 13 dBm
10 mw = 10 dBm

So, you can see the impact of adding additional power to the equasion.

The antennas that come with most access points are 2 dBi antennas. You can buy antennas that go anywhere from that to more directional models with well over 20dBi of amplification. The key here is that the total power of the solution is equal to the broadcast power + antenna amplification. So if you have a 100mw AP with a +2 dBi antenna, you have a total signal strength of 20 (the decibel value of the transmitter) plus 2 (the decibel value of the antenna) for a total strength of 22dB. If you DOUBLE the broadcast power to 200mw but keep the same antenna, then that boosts you to 23 + 2 = 25dB. If instead you buy a +12dB antenna (which are fairly common) and attach it to your AP, that boosts you signal to 20 + 12 = 32dB. Again, decibels are a logarithmic scale so going from 22 to 32dB of total strength really means your signal is 10 times stronger!

Here is a link to show you examples of the types of antennas that are available. Be careful that there are different types of connectors. The hardware link I showed above helps to identify different connectors types but be sure you have the right kind if you buy an antenna. Also, cables do not handle microwaves very well (and the 2.4GHz signal of 802.11B/G is a microwave). You need to either use a VERY short wire to connect a new antenna to the AP or you need to use cables that are very specialized and very expensive (known as LMR cables).

With a wireless network, you really have to consider both sides of the equation, so you need to consider not just the AP but also the card in your notebook. You can blast the signal from the AP as far as you want, but unless the PC can respond back, you haven't accomplished much! The bigger antennas also help to pull in faint signals, but it is hard to push range out too far without addressing both sides of the equation. If your laptop has a built-in wifi solution, you might not be able to do anything with it. Upgrading the AP may help you get the range you want (if you really just want another 100 feet and there are no major obstructions, then that would probably do it for you just fine), but there are no guarantees. If you have a card, you may be able to exchange it for one with a bit more power. And many high end cards have small ports for attaching an external antenna. Boosting the antennas on both ends might be an option.

If you can't do anything on the PC side and if you are trying to extend great distances or to an area with major obstructions, then a repeater might be your best solution. It simply rebroadcasts everything in both directions to boost all the traffic. It adds a bit of latency and a bit of complexity (you need to manage your channels more closely to ensure all the rebroadcasts aren't interfering with one another) but other than that, it is a pretty simple solution.

Anyway, those are the basics of power usage in a wireless environment. Hopefully that will give you a little better idea of what your options might be and how they might apply. Good Luck!

 

(Note: Ooops, second half was cut off due to errant typo. Here is the short version of what I went on to say)

HERE is a link to show you some of the antennas that are available. Just be careful that there are many different types of connectors. The hardware link above helps to specify what is on various pieces of equipment but be sure you get the right type. Also, wires do not do a good job of transmitting microwaves (and the 2.4GHz signal of 802.11 is a microwave) so either use a VERY short cable or you will need a special type of cable (known as LMR) which is very specialized and very expensive.

But when discussing a wireless setup, you really need to consider both sides of the equation. You can blast a signal as far as you want, but unless the PC can get a signal back, it doesn't actually do you any good. The big antennas do help you pull in weaker signals, but there is a limit to what they can do. If you truly just want to extend the range another 100 feet and there are no major obstructions, you should be fine. But if there are major obstructions (such as exterior walls of a house) then you will likely have problems unless you do something on the PC side as well. With the build in solutions, it isn't easy to make changes. If you use a card, you might be able to find a stronger one or some high end cards even have small antenna ports so that you can use an external antenna.

In instances where you are extending great distances or going through major obstacles, then a repeater might be the best option since it will rebroadcast the signal from both directions. There is a little bit of additional letency and you have to be a bit more cautious with your channel assignments to ensure all the rebroadcasts aren't interfering with one another, but generally speaking it is a pretty simple solution.

Anyway, those are the basics of wireless signals. Good Luck!

 

Many, many thanks for the suggestions, explanations and links! Because of stuctural impediments, I'm inclined to go with the repeater. I'll let you know how it goes.