A constantly growing quantity of cordless systems such as wireless speakers causes growing competition for the precious frequency space. I'm going to examine several systems which are utilized by current electronic sound systems to determine how well these solutions may work in a real-world environment. The growing popularity of wireless consumer products just like wireless speakers has begun to cause issues with several gadgets competing for the limited frequency space. Wireless networks, cordless phones , Bluetooth and also various other devices are eating up the precious frequency space at 900 MHz and 2.4 GHz. Cordless audio systems must ensure reliable real-time transmission within an environment having a great deal of interference.
The rising popularity of wireless consumer gadgets like wireless speakers has started to result in problems with several devices competing for the limited frequency space. Wireless networks, wireless telephones , Bluetooth as well as other devices are eating up the valuable frequency space at 900 MHz and 2.4 GHz. Cordless sound gadgets need to assure reliable real-time transmission in an environment with a lots of interference.
Frequency hopping systems, however, are going to still cause problems because they will disrupt even transmitters using transmit channels. Audio can be considered a real-time protocol. Because of this it has strict demands pertaining to reliability. Also, small latency is essential in lots of applications. Thus more innovative methods are necessary to ensure reliability.
One of these strategies is called forward error correction or FEC in short. The transmitter will broadcast extra information in addition to the sound data. Using this additional data, the receiver can recover the original information even if the signal was corrupted to some extent. Transmitters making use of FEC can transmit to a huge amount of wireless devices and doesn't need any kind of feedback from the receiver.
Another method employs bidirectional transmission, i.e. every receiver sends information back to the transmitter. This approach is only useful if the quantity of receivers is small. In addition, it requires a back channel to the transmitter. The transmitters includes a checksum with each data packet. Each receiver can detect whether a particular packet has been received correctly or damaged due to interference. Subsequently, each wireless receiver will be sending an acknowledgement to the transmitter. In cases of dropped packets, the receiver is going to notify 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. Making use of buffers causes a delay or latency in the transmission. The amount of the delay is directly related to the buffer size. A bigger buffer size improves the dependability of the transmission. Video applications, however, require the audio to be in sync with the video. In cases like this a large latency is difficult. One limitation is that systems in which the receiver communicates with the transmitter can usually only broadcast to a small number of cordless receivers. In addition, receivers need to add a transmitter and usually consume more current
Often a frequency channel can get occupied by a different transmitter. Ideally the transmitter is going to recognize this fact and change to another channel. To achieve this, a number of wireless speakers constantly monitor which channels are available so that they can immediately switch to a clear channel. The clear channel is picked from a list of channels which has been determined to be clear. One technique that utilizes this particular transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS
The rising popularity of wireless consumer gadgets like wireless speakers has started to result in problems with several devices competing for the limited frequency space. Wireless networks, wireless telephones , Bluetooth as well as other devices are eating up the valuable frequency space at 900 MHz and 2.4 GHz. Cordless sound gadgets need to assure reliable real-time transmission in an environment with a lots of interference.
Frequency hopping systems, however, are going to still cause problems because they will disrupt even transmitters using transmit channels. Audio can be considered a real-time protocol. Because of this it has strict demands pertaining to reliability. Also, small latency is essential in lots of applications. Thus more innovative methods are necessary to ensure reliability.
One of these strategies is called forward error correction or FEC in short. The transmitter will broadcast extra information in addition to the sound data. Using this additional data, the receiver can recover the original information even if the signal was corrupted to some extent. Transmitters making use of FEC can transmit to a huge amount of wireless devices and doesn't need any kind of feedback from the receiver.
Another method employs bidirectional transmission, i.e. every receiver sends information back to the transmitter. This approach is only useful if the quantity of receivers is small. In addition, it requires a back channel to the transmitter. The transmitters includes a checksum with each data packet. Each receiver can detect whether a particular packet has been received correctly or damaged due to interference. Subsequently, each wireless receiver will be sending an acknowledgement to the transmitter. In cases of dropped packets, the receiver is going to notify 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. Making use of buffers causes a delay or latency in the transmission. The amount of the delay is directly related to the buffer size. A bigger buffer size improves the dependability of the transmission. Video applications, however, require the audio to be in sync with the video. In cases like this a large latency is difficult. One limitation is that systems in which the receiver communicates with the transmitter can usually only broadcast to a small number of cordless receivers. In addition, receivers need to add a transmitter and usually consume more current
Often a frequency channel can get occupied by a different transmitter. Ideally the transmitter is going to recognize this fact and change to another channel. To achieve this, a number of wireless speakers constantly monitor which channels are available so that they can immediately switch to a clear channel. The clear channel is picked from a list of channels which has been determined to be clear. One technique that utilizes this particular transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS
About the Author:
You may get extra info in relation to wireless audio speakers. Also, have a look at http://forums.wakeboarder.com/viewtopic.php?t=11496&sid=0588d9beb95da9bd3a6224b515852207
No comments:
Post a Comment