Table of Contents
LTE System Information Block (SIB) Contents
The system information is very essential and the same is broadcasted by LTE eNB over logical channel BCCH. This logical channel information is further carried over transport channel BCH or carried by DL-SCH.
There are two parts in SI static part and dynamic part. Static part is called as MIB and is transmitted using BCH and carried by PBCH once every 40ms. MIB carries useful information which includes channel bandwidth, PHICH configuration details; transmit power, no. of antennas and SIB scheduling information transmitted along with other information on the DL-SCH.
Dynamic part is called as SIB and is mapped on RRC SI messages(SI-1,2,3,4,5,6,7,8,9,10,11) over DL-SCH and transmitted using PDSCH at periodic intervals. SI-1 transmitted every 80ms, SI-2 every 160ms and SI-3 every 320 ms.
System Information Blocks are grouped in SI containers. Each SI is composed of multiple SIBs. Each SI usually will have different transmission frequency and will be sent in a single sub-frame. SIBs are transmitted using BCCH mapped on DL-SCH which in turn mapped on PDSCH.
System information will be changed every BCCH modification period. Signalling Tester model MD8430A from Anritsu can be used as LTE Base Station Emulator. This will emulate LTE MIBs and SIBs over corresponding LTE channels.
系統信息非常重要,LTE eNB 通過邏輯通道 BCCH 進行廣播。此邏輯通道信息通過傳輸通道 BCH 進一步傳輸或由 DL-SCH 傳輸。
SI靜態部分和動態部分有兩個部分。
靜態部件稱爲 MIB
使用 BCH 傳輸,並由 PBCH 每 40 毫秒攜帶一次。MIB 攜帶有用的信息,包括信道帶寬、PHICH 配置詳細信息;傳輸功率,沒有。天線和 SIB 調度信息以及 DL-SCH 上的其他信息。
動態部件稱爲 SIB
通過 DL-SCH 在 RRC SI 消息(SI-1、2、3、4、5、6、7、8、9、10、11)上映射,並使用 PDSCH 定期傳輸。SI-1 每 80 毫秒傳輸一次,SI-2 每 160 毫秒傳輸一次,SI-3 每 320 ms 傳輸一次。
系統信息塊分組在 SI 容器中。每個 SI 由多個 SIB 組成。每個 SI 通常具有不同的傳輸頻率,並將發送到單個子幀中。SIB 使用在 DL-SCH 上映射的 BCCH 傳輸,後者又映射在 PDSCH 上。
系統信息將更改每個 BCCH 修改期間。來自 Anritsu 的信號測試儀型號 MD8430A 可用作 LTE 基站仿真器。這將模擬 LTE MIB 和 SIB 通過相應的 LTE 通道。
Detail
| LTE system information blocks | Description |
|---|---|
| MIB |
Carries physical layer information of LTE cell which in turn help receive further SIs, i.e. system bandwidth 攜帶 LTE 單元的物理層信息,從而有助於接收進一步的 SI,即系統帶寬 |
| SIB1 |
Contains information regarding whether or not UE is allowed to access the LTE cell. It also defines the scheduling of the other SIBs. carries cell ID, MCC, MNC, TAC, SIB mapping. 包含有關是否允許 UE 訪問 LTE 單元的信息。它還定義其他 SIB 的調度。攜帶細胞 ID、MCC、MNC、TAC、SIB 映射。 |
| SIB2 |
Carries common channel as well as shared channel information. It also carries RRC, uplink power control, preamble power ramping, uplink Cyclic Prefix Length, sub-frame hopping, uplink EARFCN 攜帶公共通道以及共享通道信息。它還具有 RRC、上行電源控制、前導功率提升、上行環前綴長度、子幀跳躍、上行耳塞 EARFCN |
| SIB3 |
carries cell re-selection information as well as Intra frequency cell re-selection information 攜帶單元重新選擇信息以及內頻單元重新選擇信息 |
| SIB4 |
carries Intra Frequency Neighbors(on same frequency); carries serving cell and neighbor cell frequencies required for cell reselection as well handover between same RAT base stations(GSM BTS1 to GSM BTS2) and different RAT base stations(GSM to WCDMA or GSM to LTE or between WCDMA to LTE etc.) . Covers E-UTRA and other RATs as mentioned 攜帶內頻鄰域(頻率相同);攜帶單元和鄰居單元頻率,以及在同一 AT 基站(GSM BTS1 到 GSM BTS2)和不同 RAT 基站(GSM 到 WCDMA 或 GSM 到 LTE 或 WCDMA 到 LTE 之間)之間的切換。涵蓋 e-UTRA 和上述其他 RAT |
| SIB5 |
Carries Inter Frequency Neighbors(on different frequency); carries E-UTRA LTE frequencies, other neighbor cell frequencies from other RATs. The purpose is cell reselection and handover. 攜帶頻率間鄰域(在不同的頻率上);攜帶 E-UTRA LTE 頻率,其他相鄰單元頻率來自其他 RAT。目的是重新選擇和切換單元格。 |
| SIB6 |
carries WCDMA neighbors information i.e. carries serving UTRA and neighbor cell frequencies useful for cell re-selection 攜帶 WCDMA 鄰居信息,即攜帶可用於單元重新選擇的服務 UTRA 和鄰域單元頻率 |
| SIB7 |
carries GSM neighbours information i.e. Carries GERAN frequencies as well as GERAN neighbor cell frequencies. It is used for cell re-selection as well as handover purpose. 攜帶 GSM 鄰居信息,即攜帶 GERAN 頻率以及 GERAN 鄰域蜂窩頻率。它用於單元格重新選擇以及切換目的。 |
| SIB8 |
carries CDMA-2000 EVDO frequencies, CDMA-2000 neighbor cell frequencies. 攜帶CDMA-2000 EVDO頻率,CDMA-2000鄰域蜂窩頻率。 |
| SIB9 |
carries HNBID (Home eNodeB Identifier) 攜帶 HNBID(主頁 eNodeB 標識符) |
| SIB10 | carries ETWS prim. notification攜帶 ETWS prim。通知 |
| SIB11 |
carries ETWS sec. notification攜帶 ETWS 秒通知 |
Sample
LTE System Information Block (SIB) Contents
Following dropdown menu will help one browse through all the LTE system information block contents. It covers LTE SIB-1, SIB-2, SIB-3, SIB-4, SIB-5, SIB-6, SIB-7, SIB-8, SIB-9, SIB-10 and LTE SIB-11.
sib1_decoded
The following code is a demostration to decode sib1 message form OpenLTE(https://github.com/osh/openlte)
void LTE_fdd_dl_scan_interface::send_ctrl_sib1_decoded_msg(LTE_FDD_DL_SCAN_CHAN_DATA_STRUCT *chan_data,
LIBLTE_RRC_SYS_INFO_BLOCK_TYPE_1_STRUCT *sib1,
uint32 sfn)
{
libtools_scoped_lock lock(connect_mutex);
std::string tmp_msg;
uint32 i;
uint32 j;
uint16 mnc;
if(ctrl_connected)
{
tmp_msg = "info sib1_decoded ";
tmp_msg += "freq=" + to_string(liblte_interface_dl_earfcn_to_frequency(current_dl_earfcn)) + " ";
tmp_msg += "dl_earfcn=" + to_string(current_dl_earfcn) + " ";
tmp_msg += "freq_offset=" + to_string(chan_data->freq_offset) + " ";
tmp_msg += "phys_cell_id=" + to_string(chan_data->N_id_cell) + " ";
tmp_msg += "sfn=" + to_string(sfn) + " ";
for(i=0; i<sib1->N_plmn_ids; i++)
{
tmp_msg += "mcc[" + to_string(i) + "]=";
tmp_msg += to_string((sib1->plmn_id[i].id.mcc & 0x0F00) >> 8);
tmp_msg += to_string((sib1->plmn_id[i].id.mcc & 0x00F0) >> 4);
tmp_msg += to_string((sib1->plmn_id[i].id.mcc & 0x000F)) + " ";
tmp_msg += "mnc[" + to_string(i) + "]=";
if((sib1->plmn_id[i].id.mnc & 0xFF00) == 0xFF00)
{
mnc = sib1->plmn_id[i].id.mnc & 0x00FF;
tmp_msg += to_string((sib1->plmn_id[i].id.mnc & 0x00F0) >> 4);
tmp_msg += to_string((sib1->plmn_id[i].id.mnc & 0x000F)) + " ";
}else{
mnc = sib1->plmn_id[i].id.mnc & 0x0FFF;
tmp_msg += to_string((sib1->plmn_id[i].id.mnc & 0x0F00) >> 8);
tmp_msg += to_string((sib1->plmn_id[i].id.mnc & 0x00F0) >> 4);
tmp_msg += to_string((sib1->plmn_id[i].id.mnc & 0x000F)) + " ";
}
for(j=0; j<LIBLTE_MCC_MNC_LIST_N_ITEMS; j++)
{
if(liblte_mcc_mnc_list[j].mcc == (sib1->plmn_id[i].id.mcc & 0x0FFF) &&
liblte_mcc_mnc_list[j].mnc == mnc)
{
tmp_msg += "network[" + to_string(i) + "]=";
tmp_msg += to_string(liblte_mcc_mnc_list[j].net_name) + " ";
break;
}
}
if(LIBLTE_RRC_RESV_FOR_OPER == sib1->plmn_id[i].resv_for_oper)
{
tmp_msg += "resv_for_oper[" + to_string(i) + "]=true ";
}else{
tmp_msg += "resv_for_oper[" + to_string(i) + "]=false ";
}
}
tmp_msg += "tac=" + to_string((uint32)sib1->tracking_area_code) + " ";
tmp_msg += "cell_id=" + to_string(sib1->cell_id) + " ";
if(LIBLTE_RRC_CELL_BARRED == sib1->cell_barred)
{
tmp_msg += "cell_barred=true ";
}else{
tmp_msg += "cell_barred=false ";
}
if(LIBLTE_RRC_INTRA_FREQ_RESELECTION_ALLOWED == sib1->intra_freq_reselection)
{
tmp_msg += "intra_freq_resel=allowed ";
}else{
tmp_msg += "intra_freq_resel=not_allowed ";
}
if(LIBLTE_RRC_CSG_IDENTITY_NOT_PRESENT != sib1->csg_id)
{
tmp_msg += "csg_id=" + to_string(sib1->csg_id) + " ";
}
tmp_msg += "q_rx_lev_min=" + to_string(sib1->q_rx_lev_min) + " ";
tmp_msg += "q_rx_lev_min_offset=" + to_string(sib1->q_rx_lev_min_offset) + " ";
if(true == sib1->p_max_present)
{
tmp_msg += "p_max=" + to_string(sib1->p_max) + " ";
}
tmp_msg += "band=" + to_string(sib1->freq_band_indicator) + " ";
tmp_msg += "si_win_len=" + to_string(liblte_rrc_si_window_length_text[sib1->si_window_length]) + " ";
for(i=0; i<sib1->N_sched_info; i++)
{
tmp_msg += "si_periodicity[" + to_string(i) + "]=";
tmp_msg += to_string(liblte_rrc_si_periodicity_text[sib1->sched_info[i].si_periodicity]) + " ";
tmp_msg += "sib_mapping_info[" + to_string(i) + "]=";
if(0 == i)
{
tmp_msg += "2";
}
for(j=0; j<sib1->sched_info[i].N_sib_mapping_info; j++)
{
if(j > 0 || (i == 0 && j == 0))
{
tmp_msg += ",";
}
tmp_msg += to_string(liblte_rrc_sib_type_text[sib1->sched_info[i].sib_mapping_info[j].sib_type]);
}
tmp_msg += " ";
}
if(false == sib1->tdd)
{
tmp_msg += "duplex_mode=fdd ";
}else{
tmp_msg += "duplex_mode=tdd ";
tmp_msg += "subfr_assignment=" + to_string(liblte_rrc_subframe_assignment_text[sib1->tdd_cnfg.sf_assignment]) + " ";
tmp_msg += "special_subfr_patterns=" + to_string(liblte_rrc_special_subframe_patterns_text[sib1->tdd_cnfg.special_sf_patterns]) + " ";
}
tmp_msg += "si_value_tag=" + to_string(sib1->system_info_value_tag) + " ";
tmp_msg += "\n";
ctrl_socket->send(tmp_msg);
}
}
RELATED LINKS
LTE BW vs FS vs RB
LTE DCI formats
LTE Mode vs MIMO
LTE Zadoff chu sequence
LTE Advanced
LTE vs LTE Advanced
LTE Vs UMB
Acknowledgement
https://www.rfwireless-world.com/Terminology/LTE-MIB-SIB-system-information-blocks.html