Accesing windows 2003 server

Here my problem, I have customer, have wireles LAN brand Correga (AP & client Wcard), IBM x205 Server with windows Server 2003 20CAL License, but there are 46 user accesing to that server. Every morning 7.00 AM till 10.00 AM LAN connection to that server is always slow. My question is : What is the real problem because of CAL licence (Setting on windows server as each divice) or wireles device brand is no good & wrong setting (using unit 7 AP)? Where the website address from microsoft I can learned & guide to fix this problem