tablets getting disconnected automatically from hotspot in ubuntu 14.04

Used hostpad for creating hotspot. Below is the configuration for hostapd:

interface=wlan1
driver=nl80211
ssid=”Kolibri”
hw_mode=g
channel=1
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0

Please suggest a configuration so that hotspot can connect 60 tablets. Your help is appreciated.