Increase range through walls!

[lbrierley]

Hello there

I'm trying to find out what the best way is of increasing range on a 3Com wireless access point so it can penetrate the walls of our 3 floor office. I'm looking at either
1. Additional access point
2. Repeater (but i worried about compatability issues as 3Com dont make a wireless repeater)
3. Antenna

Any advice would be appreciated!

Thanks
Leon