QoS requirements include a BER better than 10-2. The lower BER require-
ment results from redundant transmissions. Each key press results in trans-
missions of 7 data packages of which only one is needed for a successful
communication.
For inter-ear communication between hearing aids, a BER better than 10-3
is required. The communication is updated every 50 ms (or 20 Hz). The
hearing aids continue to amplify based on the last saved settings even when
the transmission range is exceeded or when communication is interfered.
Wireless Security Measures
Security of the wireless signals is assured through device system design that
includes:
Individual MAC address for each unit which is checked during each transmis-
sion.
A built-in pairing table which specifies valid and legitimate pairing among
units
A proprietary Widex communication protocol which checks the package
numbers during each transmission.
A Cyclic Redundancy Check (CRC) to check data validity and correct errors.
Guidance and manufacturer’s declaration
Electromagnetic emissions
The DREAM™ series hearing aids are intended for use in the electromagnetic
environment specified below. The customer or the user of a DREAM™ series
hearing aid should assure that it is used in such an environment.
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Summary of Contents for Widex Dream D-PA
Page 1: ...USER INSTRUCTIONS THE WIDEX DREAM FAMILY D PA model Receiver in canal...
Page 5: ...EC directives 47 FCC and IC statements 47 SYMBOLS 51 5...
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