What is Adaptive frequency hopping AFH?
Adaptive Frequency Hopping (AFH), introduced by the Bluetooth® Special Interest Group in the Core Specification Version 1.2, is designed to improve the robustness of Bluetooth radio performance in the unlicensed ISM band at 2.4 GHz. Facing ambient multiple air interface technologies (WLAN, DECT, etc.)
What do you mean by FHSS?
Frequency-hopping spread spectrum
Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter and receiver.
What is adaptive frequency technology?
In Adaptive Frequency Hopping, when a Bluetooth device is introduced in the network, it identifies the channels that are presently fixed for communication by WiFi or WLANs. It then re-maps the available channels for communication by eliminating the already fixed channels from the total allotted channels.
What is AFH and why it is needed?
AFH is designed to identify and exclude channels that are in continuous use by other devices or technologies, i.e. static sources of interference. AFH protects well against interference as long as WLAN and Bluetooth are not co-located.
What is piconet and Scatternet?
Description. A piconet is the type of connection that is formed between two or more Bluetooth-enabled devices such as modern cell phones. A scatternet is a number of interconnected piconets that supports communication between more than 8 devices.
What is BLE channel hopping?
Bluetooth divides the frequency band into smaller channels (e.g. 40 channels in the case of Bluetooth Low Energy) and rapidly hops between those channels when transmitting packets. To further reduce the chance of interference, Bluetooth adapts its hopping sequence.
Why is FHSS used?
FHSS is useful to counter eavesdropping, as well as to obstruct the frequency jamming of telecommunications and to enable code-division multiple access communications. It can also minimize the effects of unintentional interference.
What is the use of frequency hopping?
Frequency hopping is a technique mainly used to keep two or more RFID readers from interfering with each other while reading RFID tags in the same area.
What technology uses frequency hopping?
One of the techniques Bluetooth technology uses to overcome interference and find a clear transmission path that avoids packet collision is the application of a form of frequency-hopping spread spectrum (FHSS) called adaptive frequency hopping (AFH).
Is ble frequency hopping?
BLE technology uses the same adaptive frequency hopping (AFH) technology as classic Bluetooth technology. This enables BLE to achieve robust transmission in the ‘noisy’ RF environments found in the home, industrial, and medical applications.
What is frequency hopping used for?
How does Adaptive Frequency hopping work in WiFi?
In Adaptive Frequency Hopping, when a Bluetooth device is introduced in the network, it identifies the channels that are presently fixed for communication by WiFi or WLANs. It then re-maps the available channels for communication by eliminating the already fixed channels from the total allotted channels.
How is the frequency hopping spectrum used in Bluetooth?
Adaptive frequency-hopping spread spectrum (AFH) as used in Bluetooth improves resistance to radio frequency interference by avoiding crowded frequencies in the hopping sequence. This sort of adaptive transmission is easier to implement with FHSS than with DSSS.
What was the practical application of frequency hopping?
A practical application of frequency hopping was developed by Ray Zinn, co-founder of Micrel Corporation. Zinn developed a method allowing radio devices to operate without the need to synchronize a receiver with a transmitter.
How is the frequency hopping spread spectrum controlled?
The changes are controlled by a code known to both transmitter and receiver. FHSS is used to avoid interference, to prevent eavesdropping, and to enable code-division multiple access (CDMA) communications. The available frequency band is divided into smaller sub-bands.