Widex TV-DEX, User Instructions

Page: 48 / 76

Quality of Service for Wireless Technology in the WidexLink System
WidexLink wireless technology enables communication between two part-
ners of a binaural pair of Widex wireless hearing aids and with their matched
external devices. The requirements for the quality of service (QoS) vary
among the various components and their intended user scenarios.
During daily use, the requirements on audio streaming from TV-Controller to
hearing aids include a BER better than 10
-3
. The communication is simplex
with a bitrate of 212 kbits/s. For remote control commands the QoS require-
ments include a BER better than 10
-2
. The lower BER requirement results
from redundant transmissions. Each key press results in transmissions of 7
data packages of which only one is needed for a successful communication.
The requirements from TV-Base to TV-Controller include a BER better than
10
-3
. The communication is semi duplex with a bit rate of 2Mbits/s and a to-
tal latency <10ms (including the link from the TV-Controller to the hearing
aids) to insure high quality audio transmission.
48