WAP + PCI Comparison?

it appears I want either a combination of

Your Internet speed is distributed across each computer according to it's needs until your DSL pipe is filled. Your DSL pipe is far smaller than 54mbps, more like 5mbps (since you chose not to specify). Your high speed 108mbps is burst only. Your average speed is governed by each wireless signal and might average 10-20mbps, but of course, your DSL pipe is far smaller than this so the high-speed router is essentially useless. Useless unless you are communicating within your LAN. If all of your computers are simultaneously transfering within your LAN, then you might have a complaint about the router's transfer speed. Otherwise, no harm, no foul, except that you spent extra $$ for minimal gain.

Q

I do not want any latency/lag issues when playing my real-time internet game, and I do not want the same issues when trying to stream video to my desktop. I also do a lot of large file transfers within the LAN. That's why I was interested in hearing about the capabilities of the D-Link and Netgeat 108mbps units. I understand that more users = less overall speed. I have also seen many negative things about the 108mbps

802.11 a/b/g units, so I was hoping I could get some more good info here.

Thanks.

Quaoar wrote:

snipped-for-privacy@hotmail.com hath wroth:

Let's take your requirements apart one at a time.

1. Latency. Internet latency is controlled by the DSL/cable/satellite connection latency. Typical wireless latency is very small. For example, pinging the neighbors client radio connected at 2Mbits/sec through a dense forest yields: Reply from 192.168.1.50: bytes=32 time=5ms TTL=127 Reply from 192.168.1.50: bytes=32 time=10ms TTL=127 Reply from 192.168.1.50: bytes=32 time=4ms TTL=127 Reply from 192.168.1.50: bytes=32 time=5ms TTL=127 Note that the 2nd packet had double the normal latency. That's a "lost" packet and retransmission caused by interference from another nearby wireless system on the same channel.

With anything above a 25MHz wireless connection, latencies of 1 or 2 msec are typical. Going to 108Mbit/sec is not going to improve that much. Compared to the 15 to 30msec minimum latency for a broadband wired connection, the added latency of the wireless is minimal.

1. 108Mbits/sec will work up to a range of about 1 meter. Beyond that, it will slow down. At about 15 meters range, you're down to a

54MBit/sec connection. Range and speed are inversely related. You can improve the 108Mbits/sec range with larger antennas. However, if you're expecting 108Mbits/sec connections from a laptop, forget it.

1. Wi-Fi currently involves 3 incompatible modes. There's 802.11b, which uses a modulation scheme that's incompatible with 802.11g, which uses a modulation scheme that's incompatible with the various proprietary 108Mbit/sec enhanced speeds. By incompatible, I mean that an access point running one of these modes, will not detect the others. The result is that the configuration for these multimode access points has various "compatibility" modes, which include allocating some time slices for listening for other modes. For example, the common "802.11b compatibility mode" will slow down the maximum UDP throughput from 30.5Mbits/sec to 19.5Mbits/sec simply because it has to stop and listen for 802.11b clients.
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   for the 108Mbit/sec proprietary modes. The result is that if you actually want to use the 108Mbit/sec mode for speed, you have to turn off all the other modes, and run *ONLY* 108Mbit/sec clients.
2. Uncompressed streaming NTSC video requires about 15Mbits/sec UDP thruput which is no big deal over wireless. HDTV can go up to about

48Mbits/sec, which is a problem, but that's going to be the job of UWB Wireless USB. Since 108Mbit/sec will yield a thruput of about 55Mbits/sec thruput maximum, it's a marginal proposition for HDTV.

1. 802.11a (5.7GHz) has less range than 802.11g (2.4GHz). If you're going through walls and floors, you may have a problem (depending on building construction).

I suggest you look into MIMO based technology. It's not the maximum speed or the latency that's important in wireless. It's the ability to maintain a connection under adverse conditions and deliver the data reliably. See the article at:

a comparison of popular products and some interesting clues.

That is real interesting stuff. The Tom's Hardware site didn't really mention MIMO at all. I already planned to get a bundle of AP + PCI card from the same manufacturer in order to maximize the speed of the desktops. I didn't realize that having an 802.11b guy on the network would slow down the 108mbps stuff, however. Hmmm...

I guess I need to see who has MIMO offerings out there.

Thanks.

Jeff Liebermann wrote:

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