Member Avatar for Kilahchris

I am curious about the theoretical bandwith of 802.11G device. I understand under normal network conditions and 802.11G wireless adapter will never reach 54Mbps speed. However say these speeds are attainable (out of luck) would and usb 1.1 Wireless adapter be limited to 12mbps speed or the speed of the 802.11G spec????

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Short answer: a USB 1.1 wireless dongle will be limited by the USB bus. USB 1.1 “full‑speed” tops out at 12 Mbit/s, so even if the radio supports 54 Mbit/s PHY rates the host link will be the bottleneck and you’ll see roughly 8–11 Mbit/s of real data throughput in practice. This is the “weakest link” situation was getting at and explains the ~10 Mb/s numbers mentioned by and . (en.wikipedia.org)

Why that 54 Mbit/s figure can be misleading: 802.11g’s PHY can signal at up to 54 Mbit/s, but protocol overhead (CSMA/CA, preambles, ACKs, headers), packet size, and shared-airtime mean typical single‑client TCP/UDP throughput is much lower — commonly in the 20–30 Mbit/s range under good conditions, and the theoretical “net” ceiling for 1500‑byte packets is about 31.4 Mbit/s. If the AP has 802.11b clients or is in mixed mode the effective throughput for the whole BSS drops further. (en.wikipedia.org)

Practical tips to get closer to real 802.11g performance: use a true USB 2.0 port and a USB 2.0–rated cable or a powered USB 2.0 hub, not an old 1.1 hub/stand; confirm the adapter enumerates as “High‑Speed (480M)” in your OS (or shows a USB 2.0 root hub); install the vendor’s USB2/driver package if needed. Many product manuals and early reviews warn that G adapters need USB 2.0 to deliver 54/24 Mbit/s class throughput, so check the adapter spec if you still see ~11 Mbit/s. (pugetsystems.com)

Takeaway: for true 802.11g speeds you need both a radio that supports g rates and a host connection that won’t throttle it (USB 2.0 or better). If you’re stuck on USB 1.1, expect roughly the same practical speed as an 802.11b link rather than anything near 54 Mbit/s. (en.wikipedia.org)

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Member Avatar for feigned

Yes, 11Mbps.

You answered your own question.

To reuse an old adage, "A chain is only as strong as it's weakest link."

Member Avatar for jayant

also, one can prove just about anything theoretically.

I can prove "Icecream is better than happiness" or something like you are not one person but two :p

Member Avatar for Zachery

also be aware 802.11g is not a standard yet :)

Member Avatar for nizzy1115

Yes, 11Mbps.

QUOTE]

Yes 11 mbs would be as fast as you can go but actual data of ethernet cable bandwidth is about %60 percent efficient due to signal collisions and such and this increases over distance...im sure the same is true for wireless G...in my personal expirence i get about 10 mbps on my linksys G network...its not too fast for data transfers...but for internet its great

Member Avatar for bodmas

Thank you for this post, it has helped me resolve a similar issue I have with my wifi dongle. I can only seem to get 11mb p/s using usb 1.1.. yes i have a nail for a pc.

Word.

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