Hopping Sequence

FCC ID: 2ABOSPLAT50

Cover Letter(s)

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FCCID_3030484

Frequency Hopping System Requirements
 Sky Phone LLC

      FCC ID: 2ABOSPLAT50

    Frequency Hopping System


This transmitter device is frequency hopping device, and complies with FCC part 15.247 rule.


This device uses Bluetooth radio which operates in 2400-2483.5 MHz band. Bluetooth uses a
radio technology called frequency-hopping spread spectrum, which chops up the data being
sent and transmits chunks of it on up to 79 bands (1 MHz each; centred from 2402 to 2480
MHz) in the range 2,400-2,483.5 MHz. The transmitter switches hop frequencies 1,600 times
per second to assure a high degree of data security. All Bluetooth devices participating in a
given piconet are synchronized to the frequency-hopping channel for the piconet. The
frequency hopping sequence is determined by the master's device address and the phase of
the hopping sequence (the frequency to hop at a specific time) is determined by the master's
internal clock. Therefore, all slaves in a piconet must know the master's device address and
must synchronize their clocks with the master's clock.


Adaptive Frequency Hopping (AFH) was introduced in the Bluetooth specification to provide
an effective way for a Bluetooth radio to counteract normal interference. AFH identifies "bad"
channels, where either other wireless devices are interfering with the Bluetooth signal or the
Bluetooth signal is interfering with another device. The AFH-enabled Bluetooth device will then
communicate with other devices within its piconet to share details of any identified bad
channels. The devices will then switch to alternative available "good" channels, away from the
areas of interference, thus having no impact on the bandwidth used.



This device was tested with an Bluetooth system receiver to check that the device maintained
hopping synchronization, and the device complied with these requirements for DA 00-705 and
FCC Part 15.247 rule.

EUT Pseudorandom Frequency Hopping Sequence

Pseudorandom Frequency Hopping Sequence Table as below:
Channel: 08, 24, 40, 56, 40, 56, 72, 09, 01, 09, 33, 41, 33, 41, 65, 73, 53, 69, 06, 22, 04, 20, 36,
52, 38, 46, 70, 78, 68, 76, 21, 29, 10, 26, 42, 58, 44, 60, 76, 13, 03, 11, 35, 43, 37, 45, 69, 77,
55, 71, 08, 24, 08, 24, 40, 56, 40, 48, 72, 01, 72, 01, 25, 33, 12, 28, 44, 60, 42, 58, 74, 11, 05,
13, 37, 45 etc.


The system receiver have input bandwidths that match the hopping channel bandwidths of
their corresponding transmitters and shift frequencies in synchronization with the transmitted
signals.



Document Created: 2016-05-17 14:49:17
Document Modified: 2016-05-17 14:49:17

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