Wireless audio has become widely used. Many consumer products like wireless speakers are eliminating the cord plus assure ultimate freedom of movement. I will take a look at how most current wireless systems can cope with interference from other transmitters and how well they will perform in a real-world scenario.
The growing interest in wireless consumer gadgets such as wireless speakers has begun to cause difficulties with numerous gadgets competing for the constrained frequency space. Wireless networks, wireless phones , Bluetooth as well as other products are eating up the precious frequency space at 900 MHz and 2.4 Gigahertz. Wireless sound systems ought to guarantee reliable real-time transmission within an environment having a lots of interference.
FM type audio transmitters usually are the least reliable in terms of tolerating interference considering that the transmission does not have any means to cope with competing transmitters. However, these transmitters have a rather constrained bandwidth and switching channels can often avoid interference. Modern-day audio gadgets employ digital sound transmission and frequently work at 2.4 GHz. These types of digital transmitters broadcast a signal that takes up far more frequency space than 900 MHz transmitters and therefore have a greater chance of colliding with other transmitters.
Frequency hopping products, on the other hand, are going to still lead to further problems as they are going to affect even transmitters employing transmit channels. Real-time audio has pretty strict demands with regards to dependability and low latency. To be able to provide those, additional mechanisms will be required. An often employed method is forward error correction where the transmitter transmits extra data with the audio. Using a few advanced algorithms, the receiver is able to restore the information which may partly be corrupted by interfering transmitters. Subsequently, these products can transmit 100% error-free even when there is interference. Transmitters making use of FEC alone typically may broadcast to any amount of wireless receivers. This mechanism is normally employed for products in which the receiver is unable to resend data to the transmitter or where the number of receivers is rather big, like digital stereos, satellite receivers etc.
One more method utilizes receivers that transmit information packets back to the transmitter. The transmitters has a checksum with every information packet. Every receiver may decide if a certain packet was received correctly or damaged due to interference. Next, every wireless receiver will send an acknowledgement to the transmitter. If a packet was corrupted, the receiver will alert the transmitter and ask for retransmission of the packet. As a result, the transmitter needs to store a great amount of packets in a buffer. Similarly, the receiver will have to have a data buffer. Using buffers leads to a delay or latency in the transmission. The amount of the delay is directly related to the buffer size. A bigger buffer size enhances the dependability of the transmission. A big latency can be a problem for many applications nonetheless. Particularly if video is present, the audio must be synchronized with the movie. Additionally, in multichannel surround sound applications where a number of loudspeakers are cordless, the wireless outdoor speakers ought to be in sync with the corded loudspeakers. One constraint is that systems in which the receiver communicates with the transmitter can usually only transmit to a few wireless receivers. In addition, receivers have to incorporate a transmitter and generally consume additional current To be able to better overcome interference, some wireless speakers is going to monitor the available frequency band as a way to decide which channels are clear at any given moment in time. If any specific channel becomes congested by a competing transmitter, these devices can change transmission to a clean channel without interruption of the audio. The clear channel is picked out from a list of channels which has been determined to be clean. One technique which makes use of this transmission protocol is known as adaptive frequency hopping spread spectrum or AFHSS