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WCDMA Signaling
R&S
®
CMW-KG4xx/-KM4xx/-KS4xx
64
User Manual 1173.9657.02 ─ 11
that optimizes the support of packet data users in an R7 HSPA+ network. With
increased acceptance of packet data services, a high number of users are supported in
a cell. The main task of the CPC is to support control channels by reducing the control
channel overhead for the Dedicated Physical Control Channel (DPCCH) in the uplink,
High Speed Dedicated Physical Control Channel (HS-DPCCH) in the uplink and for the
High Speed Shared Control Channel (HS-SCCH) in the downlink. The next important
task is to minimize the latency as perceived by the users in HSPA CELL_DCH state,
and to avoid the frequent connection termination and re-establishment. R&S
CMW
supports the following CPC features:
●
UE Uplink Discontinuous Transmission (DTX)
Uplink DPCCH is transmitted from time to time according to a known activity pat-
tern. This regular activity is needed to maintain synchronization and power control
loop. The UE DTX is only active if there is no uplink data transmission on E-DCH or
HS-DPCCH.
Two uplink DPCCH activity patterns are possible per UE:
–
UE DTX cycle 1
used temporarily, after an inactivity threshold UE changes from cycle 1 to 2
–
UE DTX cycle 2
allows to transmit the uplink DPCCH less frequently than cycle 1
HS-SCCH order deactivates/activates DTX mode. This feature is available only in
reduced signaling mode.
On the picture below after the last uplink transmission on E-DCH, the UE waits for
the duration of the "Inactivity Threshold" and then switches from UE DTX cycle 1 to
the longer UE DTX cycle 2.
Fig. 2-11: Uplink DTX example, 2 ms TTI
1 = DTX cycle 1
2 = inactivity threshold for DTX cycle 2
3 = DTX cycle 2
●
UE Downlink Discontinuous Reception (DRX)
DL DRX operation is only possible when the UL DTX operation is activated.
Network limits the number of HS-SCCH subframes to be monitored by the UE in
order to reduce UE battery consumption. Parameter UE_DRX_cycle sets which
HS-SCCH subframes the UE has to monitor. The DRX also defines the monitoring
of E-RGCH and E-AGCH downlink control channels, in general, when UE uplink
data transmission is ongoing or has just stopped, the UE has to monitor these
channels.
HS-SCCH order deactivates/activates DRX mode. This feature is available only in
reduced signaling mode.
General Description
深圳德标仪器
135-1095-0799