Technical Manual
Airbridge BTS3606A CDMA Base Station
System Description
Chapter 4 Main Functions
4-7
The Control Channel is similar to the paging channel in the CDMA2000 1x system.
It broadcasts various overhead messages and transmits other uni-cast messages
such as paging message.
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Traffic Channel
The Traffic Channel transmits traffic data. It is multiplexed by multiple users at
different time.
II. Reverse channel
The reverse channel of the 1xEV-DO includes reverse access channel and reverse
traffic channel.
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Reverse access channel
The AT uses it to originate a call or respond to network paging message. The
reverse access channel covers Pilot sub-channel (transmitted on channel I) and
Data sub-channel (transmitted on channel Q).
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Reverse traffic channel
The reverse traffic channel covers Pilot Channel, Media Access Control (MAC)
Channel, Acknowledgement (ACK) Channel, and Data Channel.
--Pilot Channel
It helps with the coherence demodulation and phase estimation of the BTS3606A.
--MAC Channel
It consists of Reverse Rate Indicator (RRI) sub-channel and DRC sub-channel.
The AT uses the DRC sub-channel to report the quality of the forward channel to
the AN. The AN can adjust the rate and the sector for transmitting data to the AT
according to the message of DRC channel. In this way, the air resource is best
utilized.
The data channel of the reverse traffic channel uses the RRI sub-channel to
determine the rate for transmitting data.
--ACK sub-channel
It helps the AT notify the AN whether the data packet of forward traffic channel is
correctly received. This function helps adjust the forward rate forecast by the AT to
improve the performance of the system.
--Data sub-channel
It is used to transmit the reverse data. In the 1xEV-DO system, the data
sub-channel can transmit data at five rates: 9.6 kbps, 19.2 kbps, 38.4 kbps, 76.8
kbps, or 153.6 kbps.
