LTE系统信息块SIB：LTE system information blocks-MIB,SIB-1,2,3,4,5,6,7,8,9,10,11

Table of Contents

SI静态部分和动态部分有两个部分。

静态部件称为 MIB

动态部件称为 SIB

Detail

Sample

LTE System Information Block (SIB) Contents

sib1_decoded

RELATED LINKS

Acknowledgement

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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.

系统信息非常重要,LTE eNB 通过逻辑通道 BCCH 进行广播。此逻辑通道信息通过传输通道 BCH 进一步传输或由 DL-SCH 传输。

SI静态部分和动态部分有两个部分。

静态部件称为 MIB

使用 BCH 传输,并由 PBCH 每 40 毫秒携带一次。MIB 携带有用的信息,包括信道带宽、PHICH 配置详细信息;传输功率,没有。天线和 SIB 调度信息以及 DL-SCH 上的其他信息。

动态部件称为 SIB

通过 DL-SCH 在 RRC SI 消息(SI-1、2、3、4、5、6、7、8、9、10、11)上映射,并使用 PDSCH 定期传输。SI-1 每 80 毫秒传输一次,SI-2 每 160 毫秒传输一次,SI-3 每 320 ms 传输一次。

系统信息块分组在 SI 容器中。每个 SI 由多个 SIB 组成。每个 SI 通常具有不同的传输频率,并将发送到单个子帧中。SIB 使用在 DL-SCH 上映射的 BCCH 传输,后者又映射在 PDSCH 上。

系统信息将更改每个 BCCH 修改期间。来自 Anritsu 的信号测试仪型号 MD8430A 可用作 LTE 基站仿真器。这将模拟 LTE MIB 和 SIB 通过相应的 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 携带 LTE 单元的物理层信息,从而有助于接收进一步的 SI,即系统带宽
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. 包含有关是否允许 UE 访问 LTE 单元的信息。它还定义其他 SIB 的调度。携带细胞 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 携带公共通道以及共享通道信息。它还具有 RRC、上行电源控制、前导功率提升、上行环前缀长度、子帧跳跃、上行耳塞 EARFCN
SIB3	carries cell re-selection information as well as Intra frequency cell re-selection information 携带单元重新选择信息以及内频单元重新选择信息
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 携带内频邻域(频率相同);携带单元和邻居单元频率,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 之间)之间的切换。涵盖 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. 携带频率间邻域(在不同的频率上);携带 E-UTRA LTE 频率,其他相邻单元频率来自其他 RAT。目的是重新选择和切换单元格。
SIB6	carries WCDMA neighbors information i.e. carries serving UTRA and neighbor cell frequencies useful for cell re-selection 携带 WCDMA 邻居信息,即携带可用于单元重新选择的服务 UTRA 和邻域单元频率
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. 携带 GSM 邻居信息,即携带 GERAN 频率以及 GERAN 邻域蜂窝频率。它用于单元格重新选择以及切换目的。
SIB8	carries CDMA-2000 EVDO frequencies, CDMA-2000 neighbor cell frequencies. 携带CDMA-2000 EVDO频率,CDMA-2000邻域蜂窝频率。
SIB9	carries HNBID (Home eNodeB Identifier) 携带 HNBID(主页 eNodeB 标识符)
SIB10	carries ETWS prim. notification携带 ETWS prim。通知
SIB11	carries ETWS sec. notification携带 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; iN_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; jplmn_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; iN_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; jsched_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