Have a look at these docs. Hopefully they will help get you started;
Cisco Aironet 1300 Series Outdoor Access Point/Bridge Software Configuration Guide, 12.3(4) JA
Chapter 14 - Configuring QoS
This chapter describes how to configure quality of service (QoS) on your access point/bridge. With this feature, you can provide preferential treatment to certain traffic at the expense of others. Without QoS, the access point/bridge offers best-effort service to each packet, regardless of the packet contents or size. It sends the packets without any assurance of reliability, delay bounds, or throughput.
This section demonstrates how you can apply a QoS policy to your wireless network's voice VLAN to give priority to wireless phone traffic.
In this example, the network administrator creates a policy named voice_policy that applies voice class of service to traffic from Spectralink phones (protocol 119 packets). The user applies the voice_policy to the incoming and outgoing radio ports and to the outgoing Ethernet port for VLAN 77.
Use the Apply Policies to Interface/VLANs drop-down menus to apply policies to the access point Ethernet and radio ports. If VLANs are configured on the access point, drop-down menus for each VLANs' virtual ports appear in this section. If VLANs are not configured on the access point, drop-down menus for each interface appear.