TBF_16(PDCH硬拥塞)

NED上介绍很清楚，如下：
Downlink multislot allocation blocking (tbf_16b)
Use:
If the blocking is met regularly, there is need either to expand the territory (CS traffic low)
or TCH capacity (CS traffic high).
Note: If the statistics show that there is blocking but no upgrade requests yet, the reason
may be that the territory has been smaller than the default setting defines (CS use). The
PCU will not make an upgrade request. This is because the CS side will return the
default channels back to the PS territory as soon as the CS load allows that.
RECOMMENDED SUMMARY LEVELS: Area; SEG; BTS
Formula (NetAct names):
sum(NO_RADIO_RES_AVA_DL_TBF)
100 * --------------------------------------------------------------------
sum(req_1_TSL_DL + req_2_TSL_DL + req_3_TSL_DL + req_4_TSL_DL
+ req_5_TSL_DL + req_6_TSL_DL + req_7_TSL_DL + req_8_TSL_DL
+ req_9_TSL_DL + req_10_TSL_DL + req_11_TSL_DL + req_12_TSL_DL)
Counters from table(s):
p_nbsc_packet_control_unit

由于没有PDCH信道资源造成的上下行TBF建立失败

由于没有PDCH信道资源造成的上下行TBF建立失败，非语音TCH预清空导致

硬拥塞：指的是无PDCH信道接入；
软拥塞：能接入，但是PDCH的复用度高，数据业务的速度慢。

硬拥塞：载频的数据信道时隙全部占满，资源直接不足数据请求直接拒绝，语音占满了仅有的信道，表现不能上网。软拥塞：数据挤兑语音，把语音信道时隙变成数据信道时隙的现象，表现上网慢和难上网。

主要还是因为没有资源