Wi Fi

[#1]

Hi,
I am using a Billion 7800DXL. Recently 2 iphones struggle to connect to the wifi network. They sometimes will if they are in the same room as the router but disconnect as soon as one walks a few paces away. Most times they will say 'cannot join network' Not sure where the problem lies or how to resolve it. Any help would be much appreciated.
Thanks

[#2]

Have you looked to see whether other local routers are competing on same channel as your router?
Use a prog such as SSID.

[#3]

HI Thanks for your reply. I haven't used InSSider but have use Xirrus WiFi Inspector which does a similar function. There are no other networks on the channel I am using.

[#4]

iDevices can get their wifi configurations screwed.  On the details tab (click the arrow) select "Forget this network" and try again.

[#5]

Thanks for the reply. I have already tried doing this as well as resetting the network on both phones, and hard resetting phones. None of these worked

[#6]

What wireless channel is your router using? Try changing it to something else and see if the signal level reported by your wifi inspector improves.

[#7]

My iPhone (admittedly just a 4) got very temperamental at one stage and refused to connect unless I set the router to Channel 1 (even though 6 looked a stronger channel).  Setting to auto was a no no. And I live in a village with only one other router within range (and sometimes that doesn't even show).  I get the impression Apple WiFi is a delicate little flower.  Have you tried fixing the channel?