A constantly increasing number of wireless systems for example wireless speakers is bringing about growing competition for the precious frequency space. I'll take a look at a number of systems which are utilized by modern digital audio products in order to determine how well these products may work in a real-world environment. The most common frequency bands that can be used by wireless products are the 900 MHz, 2.4 GHz and 5.8 Gigahertz frequency band. Primarily the 900 MHz and also 2.4 Gigahertz frequency bands have started to become crowded by the increasing amount of devices including wireless speakers, cordless phones and so on.
Common FM transmitters generally work at 900 MHz and do not possess any specific way of dealing with interference but switching the transmit channel can be a way to deal with interfering transmitters. Modern audio systems utilize digital sound transmission and frequently operate at 2.4 Gigahertz. These kinds of digital transmitters transmit a signal that takes up a lot more frequency space than 900 MHz transmitters and therefore have a greater possibility of colliding with other transmitters.
FM type audio transmitters usually are the least robust when it comes to tolerating interference since the transmission does not have any method to deal with competing transmitters. Having said that, these transmitters use a fairly limited bandwidth and changing channels can often eliminate interference. The 2.4 GHz and 5.8 GHz frequency bands are utilized by digital transmitters and also have become quite congested lately given that digital signals occupy much more bandwidth compared to analogue transmitters. Frequency hopping systems, however, are going to still cause problems because they will disrupt even transmitters working with transmit channels. Audio can be regarded as a real-time protocol. As such it has stringent demands regarding reliability. Furthermore, low latency is important in several applications. Therefore more sophisticated methods are needed to ensure dependability.
Some cordless systems like Bluetooth systems and also cordless telephones use frequency hopping. As a result simply switching the channel isn't going to avoid these kinds of frequency hoppers. Sound can be considered a real-time protocol. Therefore it has stringent needs with regards to stability. In addition, small latency is essential in numerous applications. Therefore more advanced strategies are needed to guarantee reliability.
An additional approach utilizes receivers which transmit information packets to the transmitter. The transmitters contains a checksum with each data packet. Every receiver can easily determine whether a particular packet was received properly or damaged due to interference. Subsequently, every cordless receiver will be sending an acknowledgement to the transmitter. In cases of dropped packets, the receiver is going to inform the transmitter and the lost packet is resent. Because of this both the transmitter and receiver have to have a buffer in order to keep packets. This will introduce an audio latency, also known as delay, to the transmission which can be a problem for real-time protocols like audio. Normally, the larger the buffer is, the greater the robustness of the transmission. Video applications, nevertheless, need the sound to be synchronized with the movie. In this instance a large latency is problematic. Cordless systems which use this technique, however, are only able to broadcast to a restricted number of wireless receivers. Typically the receivers have to be paired to the transmitter. Because each receiver also requires broadcast functionality, the receivers cost more to produce and in addition use up more power.
Often a frequency channel may become occupied by another transmitter. Ideally the transmitter is going to realize this fact and change to yet another channel. To accomplish this, some wireless speakers continuously watch which channels are available to enable them to quickly change to a clear channel. The clean channel is picked from a list of channels which has been identified to be clear. A technology that makes use of this kind of transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS
Common FM transmitters generally work at 900 MHz and do not possess any specific way of dealing with interference but switching the transmit channel can be a way to deal with interfering transmitters. Modern audio systems utilize digital sound transmission and frequently operate at 2.4 Gigahertz. These kinds of digital transmitters transmit a signal that takes up a lot more frequency space than 900 MHz transmitters and therefore have a greater possibility of colliding with other transmitters.
FM type audio transmitters usually are the least robust when it comes to tolerating interference since the transmission does not have any method to deal with competing transmitters. Having said that, these transmitters use a fairly limited bandwidth and changing channels can often eliminate interference. The 2.4 GHz and 5.8 GHz frequency bands are utilized by digital transmitters and also have become quite congested lately given that digital signals occupy much more bandwidth compared to analogue transmitters. Frequency hopping systems, however, are going to still cause problems because they will disrupt even transmitters working with transmit channels. Audio can be regarded as a real-time protocol. As such it has stringent demands regarding reliability. Furthermore, low latency is important in several applications. Therefore more sophisticated methods are needed to ensure dependability.
Some cordless systems like Bluetooth systems and also cordless telephones use frequency hopping. As a result simply switching the channel isn't going to avoid these kinds of frequency hoppers. Sound can be considered a real-time protocol. Therefore it has stringent needs with regards to stability. In addition, small latency is essential in numerous applications. Therefore more advanced strategies are needed to guarantee reliability.
An additional approach utilizes receivers which transmit information packets to the transmitter. The transmitters contains a checksum with each data packet. Every receiver can easily determine whether a particular packet was received properly or damaged due to interference. Subsequently, every cordless receiver will be sending an acknowledgement to the transmitter. In cases of dropped packets, the receiver is going to inform the transmitter and the lost packet is resent. Because of this both the transmitter and receiver have to have a buffer in order to keep packets. This will introduce an audio latency, also known as delay, to the transmission which can be a problem for real-time protocols like audio. Normally, the larger the buffer is, the greater the robustness of the transmission. Video applications, nevertheless, need the sound to be synchronized with the movie. In this instance a large latency is problematic. Cordless systems which use this technique, however, are only able to broadcast to a restricted number of wireless receivers. Typically the receivers have to be paired to the transmitter. Because each receiver also requires broadcast functionality, the receivers cost more to produce and in addition use up more power.
Often a frequency channel may become occupied by another transmitter. Ideally the transmitter is going to realize this fact and change to yet another channel. To accomplish this, some wireless speakers continuously watch which channels are available to enable them to quickly change to a clear channel. The clean channel is picked from a list of channels which has been identified to be clear. A technology that makes use of this kind of transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS
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