We have a wired network of around 35 - 45 users and would like to integrate some wireless technology into our network without a large initial investment. Are there devices that let me connect 4-5 users with ethernet cable to a hub and the hub connects to an access point router? What I would like to do is get rid of a lot of the wires running around the office between rooms without buying wireless network cards for our desktops.
Any information regarding devices or ideas to solve this problem would be greatly appreciated.
The wireless network is just an extension of the wired network. You absolutely can continue to have a wired ethernet network running through a switch or a hub and then connect an AP to that same switch or hub in order to extend the network to your wireless users. The wireless AP acts as a bridge and forwards packets to and from the wireless network without crowding your limited wireless bandwidth with packets that travel between wired devices. Any inexpensive AP should work just fine in the configuration you are describing.
Sorry. I did misunderstand. Yes, you can do that through a wireless bridge. Several APs have that functionality, including the ubiquitous LinkSys WAP11. You simply have to purchase 2 APs and then configure them to serve as bridges instead of standard Access Points. I have used the LinkSys WAP11 in this exact configuration in order to connect buildings together without having to run cable either above or below a parking area. They do fine in that role so long as they are housed in an air-conditioned environment. There are better choices if you want to put them in an attic or other areas with adverse environmental conditions. Point to Multi-Point is also available if you need to reach multiple locations though I have never personally used that option with low-end hardware.
In this type of configuration, unless the Access Points are very close together, I would recommend turning off the diversity antenna and using a directional antenna on each unit (likely patch panels as they are easier to aim than a Yagi and will work fine at distances equivalent to long wire runs).
Generally 4 - 5 users will not create a lot of traffic, but if users are doing more than just sharing a T-1 to the Internet and checking email, you may want to look into 802.11a APs. And if bandwidth is a significant issue, then there are proprietary wireless bridges that operate in the unlicensed 5GHz space that can support up to 20mbps.
Again, sorry for the misunderstanding. Hopefully that helps, but let us know if you have any additional questions.