There are only three main frequency bands that the latest wireless loudspeakers work in: 900 MHz, 2.4 GHz and 5.8 GHz. A growing competition in the frequency band has forced manufacturers to develop new strategies to deal with the greater amount of interference. One of which I’m going to discuss in this article.
The adaptive frequency hopping technique is one of the most sophisticated methods that works by searching the entire frequency spectrum to find channels that are being used by different transmitters. The frequencies that are filled are marked as being vacant. In addition to the vacant channels there is a hop set defined as one or more empty frequency channels. When transmitting using a cordless system, the transmitter utilizes one of the available channel frequencies during a short time frame, typically up to 10 milliseconds. It then changes to the next frequency channel in the hopset. If the frequency channel is changed to another channel, both receiver and transmitter change to the next channel. This makes sure that both transmitters as well and receiver transmit with the identical frequency. In this way, the hop set has to be sent to each receiver.
If another wireless product is able to take over a channel, which is one of the frequencies that are in use the hop set needs to be changed. In such a situation the transmitter is able to scan all channels constantly and keeps a record of channels that are clear. When an active channel gets occupied it is immediately removed by the transmitter that channel from the active hop set, and then selects one of the free channels that are part of the new hop set. A list of alternative channels allows that the set of hops to be changed in a matter of minutes. This method is extremely efficient in avoiding interference and also in limiting broadcasting to channels that are already occupied.
There are additional methods that are commonly used on top of adaptive frequency hop. These methods further enhance the reliability of wireless music transmission. 메이저놀이터 is an often used method. Data buffering was developed to protect against damage or loss of packets due to inadequate reception or possibly multipath fade. Information packets delivered are identified with numbers. A checksum (often called CRC) is added to every packet. Following transmission, the transmitter stores recent information packets in the buffer it has built within. If a packet ends in being damaged or lost the receiver will to request the transmitter to retransmit the damaged or lost packet. This type of function calls for a backup channel, and also time slots where each receiver is able to receive packets from the transmitter and this system can support a certain number of wireless receivers each transmitter.