A method of operating an apparatus as a Bluetooth Low Energy device to perform the following steps to filter other BLE devices before connecting to another BLE device as a slave or a master in a BLE connected state, comprising: • receiving a packet at the apparatus from the other BLE device; • using a link layer of a controller of the apparatus to perform at least one of the following steps to determine whether response to the other BLE device is allowed: ∘ determining (640; 840) a time from previous BLE connected state as a slave or a master to the other BLE device, and then only one of: answering (660, 860) the received packet by sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is not less than a preset time value, or not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is less than the preset time value; or ∘ determining the data in a payload of the packet and not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that the payload data does not have information which the apparatus is interested in. • receiving a packet at the apparatus from the other BLE device; • using a link layer of a controller of the apparatus to perform at least one of the following steps to determine whether response to the other BLE device is allowed: ∘ determining (640; 840) a time from previous BLE connected state as a slave or a master to the other BLE device, and then only one of: answering (660, 860) the received packet by sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is not less than a preset time value, or not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is less than the preset time value; or ∘ determining the data in a payload of the packet and not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that the payload data does not have information which the apparatus is interested in. ∘ determining (640; 840) a time from previous BLE connected state as a slave or a master to the other BLE device, and then only one of: answering (660, 860) the received packet by sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is not less than a preset time value, or not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is less than the preset time value; or answering (660, 860) the received packet by sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is not less than a preset time value, or not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that a time from the previous connection of the apparatus to the other device is less than the preset time value; or ∘ determining the data in a payload of the packet and not answering (630, 830) the received packet by not sending a packet from the apparatus to the other BLE device if it is determined by the link layer that the payload data does not have information which the apparatus is interested in.