iPhone 3Gs slow wifi connection and disconnecting
I got a replacement iphone last month and all was good apart from it being really slow on my home wifi, my laptops on the same wireless network were fine. The connection was slow on everything, safari, mail, twitter, youtube or any other internet service, if it connected at all.
I did a Google search and found some info (full copy of info pasted below), from the info I changed my routers wireless standard band to 802.11b. The iPhone is proven to work better in 802.11b.
What do you know it now works spot on, thank you Google 
The other info I found, it may be usefull if the above does not work for you.
If you have access to your router, you can try these settings. But before you do, I strongly suggest that you backup your router configuration so that you can revert to your original settings anytime.
- iphone is proven to work better in 802.11b, so set your router to B only, not G or B+G.
- set beacon interval to 50 (works best for me), 100 is the default and it’s fine, you can leave that unchanged.
- set fragment threshold to 2304
- set RTS to 2305
- if you have access to DTIM, set it to a value of 1
- reboot your router and close your browser (for some reason, occasionally it’s a must)
- and finally, reconnect.optional: reset your iphone’s network settings.
As a review, we made changes to these properties:
Band (802.11b)
Beacon interval (50)
Fragment threshold (2304)
CTS or RTS (2305)
DTIM (1)
Thanks to “Nat Julian Belza” and the “http://getsatisfaction.com/apple/topics/iphone_3g_unbearably_slow_und_unstable_wifi” website.
