Tektronix BPA105, Руководство пользователя

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Glossary
Glossary- 4
BPA105 Bluetooth Protocol Analyzer User Manual -- COMPANY CONFIDENTIAL
1/2001
Encryption
Security mechanism that prevents eavesdropping and maintains link privacy.
FEC (Forward Error Correction)
The purpose of the FEC scheme on the data payload is to reduce the number
of retransmissions. Within Bluetooth, there are 2 versions of FEC: 1/3 FEC
and 2/3 FEC. 1/3 FEC is a simple, 3-times repetition of each information bit.
2/3 FEC is a (15,10) shortened Hamming code.
Frequency Hopping (Selection)
Bluetooth is characterized by its system of fast frequency hops. Ten different
types of hopping sequences are defined, five of the 79 MHz range/79 hop
system and five for the 23 MHz range/23 hop system. The two range system
hopping sequences differ only in frequency range (79 MHz or 23 MHz) and
segment length: 32 hops (79 MHz system) or 16 hops (23 MHz system).
The individual hopping sequences include the page sequence and the page
response sequence. These are used in the page procedure. Used in the inquiry
procedure are the inquiry sequence and the inquiry response sequence.
Finally the main hopping sequence used in the Bluetooth system is the
channel-hopping sequence.
Frequency Hopping Synchronization (FHS) Packet
This a special control packet revealing, among other things, the BD_ADDR
and the clock of the source device. It contains 144 information bits and a
16-bit CRC code. The payload is coded with 2/3 FEC, which brings the total
payload length to 240 bits. The FHS packet covers a single time slot.
Gateway
A Bluetooth enabled device that is connected to an external network.
Hold Mode
Devices synchronized to a piconet can enter power-saving modes in which
device activity is lowered. The master unit can put slave units into HOLD
mode, where only an internal timer is running. Slave units can also demand
to be put into HOLD mode. Data transfer restarts instantly when units
transition out of HOLD mode. It has an intermediate duty cycle (medium
power efficient ) for the 3 power-saving modes (sniff, hold, and park).
Host Controller Interface (HCI)
Allows higher layers of the stack, including applications, to access the
baseband, link manager, and other hardware registers through a single,
standard interface.
HV (High Quality Voice)
A SCO link voice packet. HV1 packets carry 10 information bytes, which
are protected by 1/3 FEC. HV2 packets carry 20 information bytes and are
protected by 2/3 FEC. HV3 packets carry 30 information bytes and are not
protected by FEC. HV packets do not have a CRC or payload header.