Technology, Support, and News Forum

[Weaver Profile Website]

Yes it is but the higher frequency allows better reception at lower power levels.

Now I am nitpicking...

I believe that to be inaccurate. Both 802.11b and 802.11g operate on the same "frequency band." This band is defined by part 97 of the FCC rules. The range is 2.390 - 2.450 GHz, correct me if I am wrong. This is why g equipment is much easier backward compatible with b equipment, when compared to the 802.11a standard, which uses the 5.something GHz range.

As far as better reception at lower power levels, I am not an EE and cannot argue that one with you.

-Weaver

[~Robrowe~ Profile Website]

Yes it is but the higher frequency allows better reception at lower power levels.

Now I am nitpicking...

I believe that to be inaccurate. Both 802.11b and 802.11g operate on the same "frequency band." This band is defined by part 97 of the FCC rules. The range is 2.390 - 2.450 GHz, correct me if I am wrong. This is why g equipment is much easier backward compatible with b equipment, when compared to the 802.11a standard, which uses the 5.something GHz range.

As far as better reception at lower power levels, I am not an EE and cannot argue that one with you.

-Weaver

You are right dude My bad it was 802.11a I was thinking about which runs in the 5Ghz range.

[OsirisX Profile WebsiteYIM]

Fixed your post, it was all in the quote box before, aksi why would a be 5ghz when the newer b and g are only 2.5ghz. Does that mean that the 802.11a is breaking the fcc's rules?

[Neuromancer Profile]

Well I used to do signals analysis for the DoD,

The thing we were taught about signal propogation is the higher the frequency the shorter the range and the more interference when passing through dense mediums.

Anyway when I go into work tomorrow I will check and see whatthe ranges are.

I am pretty sure it goes a, b, g. From shortest to longest.

Anyway the code you are talking about was lifted in may 2001 from the FCC, to free up 802.11g. Or did they shut it down again?

I would swear that b only goes 50 feet and g is supposed to go 250 LOS.

But I will check tomorrow, cuz I cant find it on google (in a 3ns search;)

[Gelob Profile Website]

this might help you

Glenn Fleishman posts a great commentary on the recent discussion about the "tragedy of the commons" of the 2.4 GHz space. Given some comments on the matter by Dewayne Hendricks, member of the FCC Technology Adisory Council and chairman of the FCC's Spectrum Management Working Group. Definitely worth a read - Glenn points out the real issues involved, the technology limitations, and the industry standards coming out designed to promote shared use of the spectrum.
This is an interesting thought experiment - will the success of the 2.4GHz spectrum (and any other unlicensed spectrum) fail due to its own success? Will illegal amplifiers turn the spectrum into another Citizen's Band? Even without illegal amps, is it doomed to failure because the density of devices will increase too quickly?

I don't think so. But it does remain an open question - how much is enough? In other words, as 802.11h and other standards that help to reduce interference become more popular, at what density of spectrum do even those methods fail? Surely there is a transmission power and density for which the specrtum becomes unusable. The question is, can technological advances outpace the bandwidth needs of the public? As more bandwidth is available over the airwaves, whether by spectrum allocation, frequency increases, or new standards for interoperable devices, at what point will the spectrum be rendered effectively unusable? To what extent is legislation or regulation needed here?

Maybe the answer lies in the fact that the unlicensed spectrum (2.4GHz, used by 802.11b and others, and 5.3GHz, used by 802.11a), while unlincensed, IS NOT UNREGULATED. Among other things, all devices have to follow FCC Part 15 rules, which means that they must be approved by the FCC before the manufacturers can offer them for sale. Perhaps the key to saving the commons is to ensure that these devices are interoperable and, well, for the lack of a better term, polite to other users of the spectrum.

Of course, this would be an extension to the FCC's regulatory capacity - essentially asking it to endorse certain protocols at a layer above the radio. However, I think that by focusing on protocols rather than products, it (a) does not act anti-competitively, and (b) promotes the public good (remember, WE own the airwaves!) by enabling more functionality and usability of the spectrum we use. And if we are smart, we can agree to a level of interference protection that all higher level radio protocols can use, allowing for even greater flexibility.

Think of it as a new layer, sitting between layers 1 and 2 of the network stack - the new layer would provide for interference detection, channel switching, and possibly even automated changes in the spread spectrum algorithms to make sure that different devices, running different higher-level protocols, would automatically detect each other and not interfere with each other.

http://www.sifry.com/alerts/archives/2002_05.html

[Neuromancer Profile]

Yep

Now an industry trade association, the Wi-Fi Alliance, has approved uniform (802.11) standards that support interoperability of connected devices. The standards are 802.11b, 802.11a and 802.11g.

Though theoretical ranges of 802.11b and 802.11g devices are commonly expressed to be 1,000 ft., walls and other solid items in a room reduce the signal travel distance. Practical ranges are about 100 to 150 ft.

The 802.11a format, which does not go through walls and floors as well as the other two standards, extends out only 25 to 75 ft. After those distances, the farther a device is from the transmitter, the weaker the signal and the slower the transfer rate.

From feldman on computers

Still I will check the Belkin package and see the difference is in range or just speed.

[OsirisX Profile WebsiteYIM]

Thanks

[glexp Profile YIM]

Range is not necessarily a function of operating frequency. Yes, at higher frequencies it becomes harder to penetrate obstructions. Witness the use of sonar to locate subs. Lower frequency (sound waves vs. microwave) operate better in higher density (water vs. air) environments....

Part of the range restriction is due to the antenna design of the wireless unit. The antennas on routers are omni-directional. They transmit with equal power in all directions. Changing the design of the antenna so that it transmits within a smaller angle will greatly increase the range by "focusing" the total power into a smaller area. Unfortunately, the receiving equipment (your PC) needs to be within that angle. Higher power output will also extend the range. But that is regulated by the FCC. Don't know what they are, but the FCC limits the power used on certain frequencies. Higher power can be used, but that requires the operator of that equipment to have a license (a good reason to get a HAM radio license ). There are several outfits that allow you to increase the range of your wireless system by using re-designed antennas or putting a small amplifier in-line. Just do a google search on "router antennas".

Hope my ramblings don't add to the confusion...

[OsirisX Profile WebsiteYIM]

I've seen antennas on compusa.com that was said to extend the range and power of the router 3x. Isn't that gonna be again the rules though, and does it really work?

[~Robrowe~ Profile Website]

If it is an a or g I wouldnt much see the problem they are pretty strict with the 5GHZ range though. As glexp was so kind to point out simply changing antenna styles proves to be fruitful. they have flat panel ones that transcieve in one direction (unidirectional for the geeks) that (let me think cause I feel weaver lurking )in theory would double your range but theory seldom proves to be accurate so lets just say it will greatly improve your wireless performance. You just have to be smart about the antenna placement and the placemant of the machines using the network. But if you think about it if you have it on an outside wall pointing back your focusing on what needs to be covered and not wasting 180deg or more of your capabilities. There are places for omnidirectional antennas but IMO practicality often leads to unidirectional and the dispersion of a few extra waps on a larger scale system. On a home network you wont have the need for more than one wap unless your home happens to be Buckingham palace.