A display device which can operate at low power consumption is provided. Compressed air is blown to the substrate to remove the washing liquid. The first set has uniform faced poles. In another example, the access network can determine a channel type upon which the support a multicast session, can indicate the channel type selection to the at least one access terminal in an announce message and can then transmit the multicast messages for the multicast session on the selected channel type. The present invention reduces the search count and improves the search efficiency.