Is Wireless Full Duplex or NOT?

rampel

Member
Jun 27, 2003
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Hi all,

I'm using the "D-Link" (brand name) DI-714P+ Wireless Router with the DWL - 520+ Wireless PCI Adapter on a small home lan (OSX & WinXP Pro)

The Router is connected to a Cable modem. both machines can internet and exchange files between them

I am getting conflicting information regarding this Wireless setup ability to run in Full Duplex Mode.

Some tell me it's possible. (But don't tell me how)

Some say No way Jose, that any wireless is by default Half Duplex only Period

Could you please clarify this issue for me?

Also, if it IS possible how do I configure this setup for Full Duplex?

TIA

ps
(The Installation manual does NOT mention Duplex at all and the FAQ page on D-Link's Home page mentions Duplex just once and not for these Items)
 

skyking

Lifer
Nov 21, 2001
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Wireless is not full duplex. There is only one channel for the traffic to run on, so it takes turns.
 

pickel

Member
Jul 29, 2003
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You wouldn't be able to downnload and surf the net if it wasn't full duplex. I have the same router with four computers and one laptop ( wireless) and we keep thsoe network lights flashing all the time. Don't know how it works , but it does :)
 

skyking

Lifer
Nov 21, 2001
22,781
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Originally posted by: pickel
You wouldn't be able to downnload and surf the net if it wasn't full duplex. I have the same router with four computers and one laptop ( wireless) and we keep thsoe network lights flashing all the time. Don't know how it works , but it does :)

so all the time my network is running half duplex, i can't download or surf the net? you could have fooled me.............
 

rampel

Member
Jun 27, 2003
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Well, I have to disagree

It has just been explained to me (on another forum) how it IS possible to d/l and surf the net in Half Duplex (not full)
If your interested I'll post it here 4 U
 

skyking

Lifer
Nov 21, 2001
22,781
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LOL, I just set my network connection manually to 10/half duplex, and here I am, posting away;)
 

ktwebb

Platinum Member
Nov 20, 1999
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To run a full duplex microwave LAN you'd need two radio's, both in the client and AP. Even then, once you added nodes to the WLAN you'd need another two radios in the AP to have dedicated bandwidth. It's just isn't feasible to do that. There is full duplex bridging but there is NO full duplex WLAN hardware available. 802.11 AP/client infrastructures (all variants) are half duplex. The person(s) telling you there is full duplex capability in current available wireless setups are simply misinformed, are talking about WAN bridging (not LAN gear), or are reading about future equipment. If so, then tell em to give you a link. I'd be interested to read about it. The AP would need a dedicated TX/RX radio for every node though so it'd be pretty pointless. No scale to tip. Half-Duplex.

"You wouldn't be able to downnload and surf the net if it wasn't full duplex."

Back to the books pickel.
 

rampel

Member
Jun 27, 2003
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LOL,

That does it. My hunch was good, they were either lying or talking without knowing enough about it
 

cmetz

Platinum Member
Nov 13, 2001
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rampel, 802.11b is CSMA/CA, which is half duplex. At a very rough level, think of old (non-switched) Ethernet, which was a bus on which only one station at a time can send.

pickel, sure you can. Your 802.11b network is half duplex, meaning it cannot send and receive at the same moment. That doesn't mean that you cannot both send and receive. Only that the two are mutually exclusive in time. Because your 802.11b network is a whole lot faster than your Internet connection, each side having to wait to send until the other's done turns out not to be a visible bottleneck.
 

Jeff7

Lifer
Jan 4, 2001
41,596
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Originally posted by: pickel
You wouldn't be able to downnload and surf the net if it wasn't full duplex. I have the same router with four computers and one laptop ( wireless) and we keep thsoe network lights flashing all the time. Don't know how it works , but it does :)

Surfing the Internet on half duplex is like two people holding a conversation. One side talks, the other listens, then they reverse. If people were full-duplex capable, they could talk AND listen at the same time - the conversation would go faster then.
PC's are the same way - half duplex means that while one is transmitting, the other is receiving, and vice versa. Full duplex means that the device can send and receive at the same time.