目前发现在GSM网络下做语音呼叫，通话结束以后网络下发的 [b][color=#4169e1]channel release[/color][/b] 消息。这条消息有时候会携带字段 cell selection indicator，该字段用于指示UE要不要做小区重选。但是更多的时候消息中并没有带cell selection indicator这个字段。

我想问一下做接入的同学，网络一般在什么时候会携带cell selection indicator？在是否携带这个问题上是否有相关规范可遵循？

谢谢！

UE则关于这条消息的LOG如下:

2012 Aug 28 08:10:06.917 [1F] 0x512F GSM RR Signaling Message -- Channel Release
CHANNEL_RELEASE
rr_cause
rr_cause_val = 0 (0x0)
ba_range_incl = 0 (0x0)
group_chan_desc_incl = 0 (0x0)
group_ciph_key_num_incl = 0 (0x0)
gprs_res_incl = 1 (0x1)
gprs_res
ack = 1 (0x1)
ba_list_pref_incl = 0 (0x0)
utran_freq_list_incl = 0 (0x0)
cell_select_ind_incl = 1 (0x1)
cell_select_ind
LENGTH OF CELL SELECTION INDICATOR = 5 (0x5)
const_001 = 1 (0x1)
struct1_count = 1 (0x1)
struct1[0]
const_1 = 1 (0x1)
UTRAN FDD Description
bandwidth_fdd_present = 0 (0x0)
FDD-ARFCN = 10713 (0x29d9)
fdd_indic0_present = 1 (0x1)
FDD_Indic0 = 0 (0x0)
NR_OF_FDD_CELLS = 1 (0x1)
FDD_CELL_INFORMATION Field = 892 (0x37c)
const_0 = 0 (0x0)
cell_chan_description_incl = 0 (0x0)
enh_dtm_cs_release_incl = 0 (0x0)
vgcs_ciphering_params_incl = 0 (0x0)
group_chan_desc2_incl = 0 (0x0)
talker_identity_incl = 0 (0x0)
talker_priority_status_incl = 0 (0x0)
vgcs_amr_config_incl = 0 (0x0)
individual_priority_incl = 0 (0x0)