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Standard User john7
(member) Thu 21-Jul-11 16:04:06
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problems using two wirelesses?


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I have a dell with wireless card, using it with a Billion 7800N. Speed is not very good, the dell says connected at 70Mb and a Bullion USB wireless comes in at 6oMB. Running transfer tests between the desktop and laptop I am getting about 2 to 3 Mb sec. Running both wirelesses together this goes up to 4 to 5 Mb sec. doing backups etc. extra speed could be useful, is there a problem in using both together?

My Billion is about 4meters and two stud walls away.
Standard User john2007
(legend) Thu 21-Jul-11 16:26:44
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Re: problems using two wirelesses?


[re: john7] [link to this post]
 
Are you confusing units? The wireless speeds are probably being reported in (mega) bits per second whereas the data transfer speeds may well be being reported in (mega) bytes per second. A byte is normally 8 bits.
Standard User john7
(member) Thu 21-Jul-11 22:55:57
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Re: problems using two wirelesses?


[re: john2007] [link to this post]
 
Very likely I have Mbps shown in the wireless network and sharing centre and Mb/second when copying over the network.
But I still get much higher speeds with both when both are used together and its if itís OK to use both together I'm trying to find out.


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Standard User prlzx
(committed) Fri 22-Jul-11 01:26:29
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Re: problems using two wirelesses?


[re: john7] [link to this post]
 
When you say you are using both wireless together, is the desktop wired only, and on the laptop you have both a built-in wireless card and a USB wireless dongle that came with the Billion router?

If so, and you have connected both wireless adapters to the same network, it is very unlikely to be using "both together", unless you have found a hack to run link aggregation over unmatched wireless links.

The OS will make a choice which is the "best path" to the network (this will show with the lower metric) and transfer the data only through that. The metric may change dynamically for wireless interfaces.

So, if you consistently see a faster transfer when you activate the "second" wireless thing, that one will be the faster one. Disable the "first" one and see what happens.

Edit:
Wireless adapters which have multiple antennas can transfer data faster than those with a single one. Also I don't know if any of your kit can use the 5GHz band which may be faster. In terms of channel widths, on 2.4GHz not all kit is compatible with a 40MHz (dual channel) config and there is more chance of interference; single channel may work better. On 5GHz a 40MHz channel width is generally usable.

If you have both wired and wireless interfaces active on the same PC, and the destination can be reached through either interface, the OS will tend to favour the wired one if that reports a higher link speed.



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Edited by prlzx (Fri 22-Jul-11 01:38:01)

Standard User john7
(member) Fri 22-Jul-11 12:22:55
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Re: problems using two wirelesses?


[re: prlzx] [link to this post]
 
Thanks for reply. I have been trying out the different options. The transfers were with the deck PC not in use (but clearly odd programs like Norton etc. may be access updating) and copying the same 85Mb file each time.
I donít have 5GHz and the desk top doesnít have a wireless connection (its next to the modem/mater BT socket)
My original short test was flawed it seems as W7 wasnít selecting the best connexion but using the one enabled before the 2nd was also activated. Thus it turns out the Dell card is better than the Billon by some way (which surprised me as the cars is a basic one and apparently only has one aerial compared to the Billon having two.
It I do the copying in the same room the Billion card has over 8Mb while the Dell gets to about 5Mb so clearly the Billion card is much poorer at dealing with what is a small increase in distance and obstructions.
What I found is in line with the below, this was done changing the radio bands a number of times which made no difference that I could see. inSSIDer 2.0 shows just one other user and thatís a low signal, the advantage of being rural; and thick stone walls!
Billion only about 1st 2, 2nd 1.9, 3rd 1.3 Mb
Both (after doing Dell tests) 1st 3.5, 2nd 3.9, 3rd 3.6 Mb
Dell 1st 4.8, 2nd 4, 3rd 3.8 Mb
Standard User prlzx
(committed) Sat 23-Jul-11 12:35:04
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Re: problems using two wirelesses?


[re: john7] [link to this post]
 
Just to clarify, is the Dell wireless card integrated into the laptop or is it a pluggable thing?
If it's a pluggable I guess you were removing it before running the "Billion-only" tests.

Whereas if the Dell wireless is integrated into the laptop can I take it that you disabled that card to run the "Billion-only" tests? It's not enough to disconnect it from the network, you need to turn it off (in Network adapters).

Like you I would have expected the Billion adapter to work better if it came with the router and they were designed to work together. However wireless and antenna placement is one of those things where practical performance does not always live up to paper specs.

Other factors can be in play:

- it may be that an integrated antenna can be more elaborate
- some people find better performance from a USB wireless adapter by using a short USB extension cable to provide some separation
- the placement of the router matters
- USB devices can end up sharing bandwidth (e.g. with an internal webcam) depending on the laptop innards, whereas an integrated wireless could have a more direct connection (PCI / PCIe).

Mainly I wanted to confirm that Windows won't be able to use 2 connections in parallel to the same router to any benefit and it actually upsets networking as the laptop appears twice on the same network rather than once with 2 "lanes". This applies whether the 2 connections are both wireless / wired or a mixture.

The only way I know to use multiple connections in parallel is where a smart / managed switch supports Link Aggregation and the computer NICs / driver support the same (teaming or bonding). In this case the switch treats the 2 ports as 1 combined interface, as does the computer.

This is most often done with server NICs or to make a "fat pipe" between switches for the backbone of a network hance it's rarely needed on a home network.

So in your case it boils down to a choice of using whichever card works best in the room you mostly use the laptop, or using the one that is reliable in all areas (even if not the faster one at close range - where you could wire in!).



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Edited by prlzx (Sat 23-Jul-11 12:42:38)

Standard User john7
(member) Sat 23-Jul-11 16:41:54
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Re: problems using two wirelesses?


[re: prlzx] [link to this post]
 
Yes its an integral Dell Wireless 1501 card, support have said it 130Mb but has only been coming up as 72Mb on the wireless information in network management, the Billion on the other hand is reported at its 150Mb).
There is a hot key to turn off the Dell wireless and I have checked its removed in the wireless and network management and the same when disabling the Billion (though the USB light goes out so is easy to ensure that off).
I am getting a powered hub so will be able to see if having it off the laptop helps.
I will also give disabling the webcam (never us it anyway) when I give it another session.
Will post back when I try out these two changes and have been onto Dell re the card claimed to be 130 but only coming up as 72Mb in W7.
Thanks for your help prlzx.

Edited by john7 (Sat 23-Jul-11 16:42:39)

Standard User prlzx
(committed) Sun 24-Jul-11 03:00:31
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Re: problems using two wirelesses?


[re: john7] [link to this post]
 
Slightly scary chart here:
http://wireless.agilent.com/wireless/helpfiles/n7617...

11n stuff that doesn't mention MIMO will probably be limited to single spatial stream, MCS0-7

Most consumer kit does not mention the MCS modes it can do, rather it is often branded:
150Mbit/s (likely MCS0-7)
300Mbit/s (likely MCS0-15)
600Mbit/s (likely MCS0-31)

Based on your best data rates (Mbit/s, link speeds as reported when in room with router)
and from your descriptions of the kit it looks like you are achieving MCS7 or MCS15.

If you can look in your router's wireless settings for the following for maximum compatibility:

channel width: set it to 20MHz (or single channel or untick wide channel)
guard interval (GI): set it to long (or untick short GI)
(stuff in brackets as the interface might describe it in a different way)

With these settings the expected data rates are 65 or 130

If the Dell card is supposed to be up to 130 you'll see if it can achieve MCS15 but only with a long GI
- also note what the Billion dongle can do while the router is in this mode.

Then change the channel width to 40MHz. If the Dell card stays the same but the Billion dongle gets a higher rate (e.g. 135) you'll know the Billion supports the wide channel setting where the Dell does not.

At this point you could check the Dell card properties (or via Device Manager) to see if the driver exposes any settings relating to GI or channel width..

Then on the router with short GI set, try 20MHz width, followed by the wide channel settings again.

By matching the reported data rates to the chart you should be able to see what combinations are supported.

Data rate is a link speed generally reported as the total in both directions, rather than the throughput for your transfers which you can expect to be rather less.

, and the links will adapt at lower data rates at lower signal levels.

My stuff about the webcam was a bit misleading. It would only be something to consider if you saw a drop in usable throughput on a USB dongle, just by previewing the webcam (not even being on a video call where you'd expect it to take some network bandwidth anyway).



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Edited by prlzx (Sun 24-Jul-11 03:27:24)

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