Panasonic SA-HT640WP Service Manual page 21

Does the system support any mode to save power consumption?
Yes, it has POWER SAVING SCAN mode. When the communication link is lost, the slave starts scanning procedure to re-establish
the link. If the slave cannot find the master within a certain amount of time (info stored in EEPROM), the slave automatically goes
into power saving scan mode.
How does the system handle interference from other 2.4GHz RF devices?
It adopts Adaptive Frequency Hopping Spread Spectrum (AHSS) technology to avoid interference.
How does the system handle interference from other 2.4GHz RF devices?
The system supports 3 types of Spread Spectrum. These are
1. FHSS - Frequency Hopping Spread Spectrum
2. AHSS - Adaptive Frequency Hopping Spread Spectrum
3. Fixed Channel Mode
FHSS refers to the conventional 79 channels (or 23 dependent on the country) hopping of Bluetooth. Devices using such hopping
method receives a lot of interference from other devices that use 2.4GHz range frequency such as WLAN and other Bluetooth
devices. FHSS, being built to avoid interfering with other devices, rather interferes a lot with devices that has high output power
using 2.4GHz frequency range and with other FHSS devices. During initialization, system scans 79 channels (or 23) and selects
the clear, non-interfered and reliable channel and starts the communication between master and slave. During the channel link, the
channel becomes unreliable and the error detection from FEC block exceeds the preset error threshold value, the system executes
scanning, as in initialization, and reselects new clear and reliable channel.
FHSS and AHSS can be selected by setting appropriate parameters on the EEPROM.
In Fixed Channel mode, 4 frequency levels can be selected (2.410GHz, 2.430GHz, 2.450GHz and 2.470GHz)
Spectrum distribution characteristic of 2.4GHz RF signal
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SA-HT640WP / SA-HT640WPC