Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations Mike Lewis on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Wireless setup not impressive

Status
Not open for further replies.

silk1976

IS-IT--Management
Mar 31, 2003
19
US
I'm writing this to see if anyone else out there has any advice or tips to offer. It seems as though my wireless setup is not very stable and the range is pretty poor.

Yesterday I purchased a Belkin Wireless Cable/DSL Gateway Router (Model #F5D6231-4, 802.11b) and an SMC Wireless adapter (Model #SMC2635W) for my laptop.

My setup can be described as the following - I have all my computer equipment on a set of shelves (metal frame, wood surface). My W2K machines are on the bottom shelf, and I put the Wireless router on the top shelf, about 6' off the ground. I should also mention that I live in a basement-converted-to-apartment, and the ceiling height is about 6.5 feet, which means the router is about 6 inches from the ceiling. I've found this height works slightly better then the original height I had it at, which was the middle shelf at about 3' off the ground.

Anyway, I noticed that while my laptop is in the room with the router, the signal strength is pretty good - around 95-100%. However, in certain particular spots (seems to be when the metal frame of the shelves is in the middle of the LOS between the wireless card and the router), the signal drops dramatically, and pings to the router time out. This I can live with, because it's not that big of a deal and I can justify why the signal wouldn't go through the metal (although it does seem odd that the signal would be that weak when the two wireless pieces of hardware are only 6' away from each other!).

So the next issue is that when I move my laptop to the next room, the signal drops completely. The wall between the rooms is not anything out of the ordinary (it's not brick or anything - just seems like a normal dry-wall based wall). I'm very surprised that the signal fades to nothing through one wall.

There are a couple things I can think of as being hte problem:
1) compatibility issues between the Belkin router and the SMC network adapter.
2) One of the pieces of hardware is a POS
3) The presence of a monitor about 3' below the router and the presence of a TV about 10' from the router (in the room I'm trying to get my laptop to pick up a signal from) could be ruining the signal.

Basically, this is my first experience with setting up wireless - so I'm trying to get an idea of whether my ideas of wireless networking were unrealistic to begin with. I kinda think not since I've been to several hotels around the country and had wireless access through the walls there. But I could be wrong in my expectations. Also, I'm just trying to get a sense of whether having equipment from different manufacturers could play a role (I have heard of compatibility issues - but I figured that since the 802.11b standard has been out for a while now, and that I *do* get a signal when near the router, that compatibility wouldn't be a big deal). Or maybe I just bought two crappy pieces of hardware.

Any thoughts would be appreciated!
 
I tend to think the problem is 2,1,3 in that order.

I have not had any experience with SMC or Belkin wireless products, but I have not heard good thing about them. Try borrowing another make wireless router. I personally like Linksys and Netgear stuff. Also try another PC card as well.

I have never had a compatibility issue with different vendor equipment. That's not to say there isn't compatibility issues. It's just that the brands I've used (Netgear, D-Link, Linksys, Orinoco) have never had a problem in mixed environments. Try upgrading the firmware on both the router and the PC card to the latest version. This may help with potential compatibility issues.

Finally, while monitors and other device that emit EMI can potentially cause problems, I haven't had any issues with mine and my router is closer than 3' from my 19" monitor.

Hope that helps.
 
I suggest you try and lose the metal framework of the shelving unit. My guess would be you've got metalwork within a few inches of the wireless radiating elements, and it's absorbing a substantial amount of the RF signals from your wireless system. Also, the horizontal and vertical elements of the shelving framework could be acting as reflectors to the signal which could be why it doesn't seem to work next door. The other thing to look at is the material used in the wall between the two rooms. If it's a partition wall, there may be metal reinforcing within it, or even some sort of metallic insulation material. Even a brick or stone wall can seriously attenuate the very small RF signals those wireless LANS generate. The signals from these units need to be kept at fairly low output levels, otherwise you end up microwaving your brains!


ROGER - G0AOZ.
 
Play with the antennas on the router. If you are using a PCMCIA network adapter, its antenna orientation is essentially horizontal.

Take one of the router antennas and point it parallel to the floor.
 
I am about to go to a wireless home setup this weekend and I will be using the Linksys gear.

I had a "wired" network at our last residence and it was with a Belkin Router. I had some serious compatability issues with this router and had to constantly reset our internet connection.

I would take that stuff back and go with the Linksys gear. I also agree with the post about losing the metal shelving. That could also be generating some problems...

Peace,
Don
PC Technician

"Of all the things I've lost, I miss my mind the most..." - Steven Tyler
 
Metal shelving can actually help. It reflects the signal that normally would be directed to your floor. I have seen professional installations where a cookie sheet was inserted under the access point or wirelesss router for exactly this purpose.

One thing that could help is to use the Micahel Erskine trick of using parabolic reflectors to redirect your antennas signal. If have used these several times with good effect. You make them out of shirt cardboard, aluminum foil and a glue stick. Believe me you can get a 12 dbi increase for about 15 cents in material. See this site, highly recommended:
I know this sounds like a pringle can hack, but it is not. Highly recommended.



I use the "EZ-12". Be certain to see his notes on antenna types to select the correct template.
 
Two points worth mentioning I think...

I agree that a metal framework, like shelving for instance, can occasionally "help" or increase the signal in a given direction. However, it's my experience that in a majority of cases it'll absorb more than it reflects or re-radiates.

The reflector idea is fine if you can live with extraneous pieces of metallic material dotted around your office or home. However, you should remember that a reflector will concentrate the signals into a specific direction rather like a TV antenna, and that signals off to the side will be severely attenuated. Fine if you only have one other station on your network, but for three or more PCs you'd be very lucky to get them all to communicate unless they were all positioned in a straight line.


ROGER - G0AOZ.
 
Goaz,

1. There is no way metal will absorb the signals.

2. I think you should visit the site and read the linked material, including the waveforms both horizontally and verticly.

They most certainly do not have to be in a straight line.

For example, I use these where the only suitable location for the router/AP is in the basement at one end of a house. There is no need to provide wireless service to the neighbors. The signals are reflected towards the center of the house and upwards, as the floor does not require wireless service either.

Netstumbler shows an increase of 12 dbi for any before and after measurement on the subsequent three floors above of the house from any reference point.

 
I should note that the reflectors are 4 inches wide, by six inches long if laid flat. Shaped as suggested in the link above they have an insignificant footprint as it were.
 
It's my belief that if you're building a reflector for an active aerial element it needs to be a specific measurement relating to the frequency of the signal. It also needs to be placed a specific distance from that radiating (and receiving) element. As soon as you add any passive element to aerial of this sort it no longer exhibits onmidirectional characteristics. The polar diagram of a two element aerial (if properly cut and aligned) will clearly show most gain in the main lobe which will be in a straight line out from the active element with minimal signal from behind the reflector. There will be smaller lobes to the sides but these are likely to be reduced over what could be expected from an isotropic radiator.

As I understand it, radio waves can be absorbed by metal in the same way they're absorbed by buildings, earth or rock. If the metallic object isn't resonant (e.g. metal equipment rack) at the desired frequency then the signal will manifest itself as a standing current or even heat. Some of it might well be re-radiated, but in all sorts of odd directions and at very limited powers.

Anyhow, this is getting away from the original post! By all means experiment as per that article, but bear in mind each location is going to offer different signal patterns depending upon the building, furniture, metallic objects and people, in the vicinity.

Good luck with it.


ROGER - G0AOZ.
 
The technology and frequency is the same 2.4GHz, so cleverly picked by the authorities to form the band that almost evry gadget nowadays uses. Of course they forgot to mention that 2.4GHz is the extact, precise frequency that your microwave uses to cook meals. Did you ever wonder WHY DECT phones (you know, the standard digital, home phones) mention nothing of it in their documentation? And you thought mobile phones are bad? Granted, a DECT phone is less powerful than a mobile, but on the mobile you need harmonics to get to 2.45GHz (the cooking frequency), on the DECT phone it's its fundamental!!!

Secondly, and more to your problem, if you put a DECT phone base station at the same place where you keep your wireless base, you will see that there is no problem with linkage to the handset(s). So at the same frequency, the DECT base station has no problem whereas the Wireless Station has. That means the Wireless station is severely handicapped, for some reason, which I am sure is not to our benefits.

I suggest move it away from large structures, I found that when I move mine more towards the middle of a room (and high) the signal can reach farther in the house. I suppose the best place to have it would have been the middle of the loft.
 
akisT,

The router in question uses DSS, and is not tied to a single channel. While channels overlap in part, they are not pegged at 2.4, see this channel guide for an excellent picture of the frequencies used:
I think you have 802.11b in mind. This thread is discussing 802.11g.
 
My main points were
(a) DECT (digital) telephones, plus hundreds other devices use 2.4GHz which is the cooking frequency. Who chose that frequency?!
(b) If the DECT base station can do it at the same house/room/position, so should the wireless. No excuses.
 
There is not a log of unregulated bandwidth available for unlicensed use in the spectrum.

This is why the 900 mhz. and 2.4 ghz is used. The microwave use is tied to the frequency of the brownian motion of water particles, so microwaves have less choice.
 
Ok - so here's an update:

I've tried the router/card at my girlfriends apartment, and really had no better luck. It just appears as though communications die going through a wall. I did this mostly to see if possibly my wall was too thick or there was some obstruction in it.

So I borrowed a coworkers wireless card (D-link) and same symptoms - works great in the room with the router, can't go through a wall.

I think it can be narrowed down to a POS router. I'll go get a linksys and see if I have any better luck!
 
It may also be linked to foil backed insulation in the wall. This is common on drywall construction in apartments.

Along with aluminum studs instead of metal.

I did see that your Belkin was the lowest rated in the last PC Magazine reviews of wireless routers.
 
late update:

I bought an SMC wireless router, plugged it in and it works like a charm.

Guess the Belkin routers are POS's. From now on, I use them only for cabling needs :)
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top