日志
手机开机流程
热度 2 |
1、涉及协议主要包括
TS23.122 Technical Specification Group Core Network and Terminals;
Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode
TS25.304（在LTE中对应的为TS36.304）Technical Specification Group Radio Access Network;
User Equipment (UE) procedures in idle mode and procedures for cell reselection in connected mode
Technical Specification Group Radio Access Network;
Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode
2、UE在开机时的行为可以分为：
PLMN选择和重选，
小区的选择和重选，
位置登记.
3、UE开机后，首先应该选择一个PLMN。当选中了一个PLMN后，就开始选择属于这个PLMN的小区。当找到这样的一个小区后，从系统信息（广播）中就可以知道邻近小区（neighboring cell）的信息，这样，UE就可以在所有这些小区中选择一个信号最好的小区，驻留下来。紧接着，UE就会发起位置登记过程（location update or attach）。成功后，UE就成功的驻留在这个小区中了。
4、小区驻留的目的
1.It enables the MS to receive system information from the PLMN.
2.如果MS想发起一个呼叫，它能够在驻留的小区上在控制信道上通过初始接入网来发起这个呼叫。
3.如果PLMN收到一个MS发起的呼叫，它能够（在多数情况下）知道这个MS的小区所在的注册区上，然后它能够在这个注册区的所有小区的控制信道给MS发送paging消息，MS接收这个paging消息，因为它调到在那个注册区的小区的控制信道上，并且MS能够响应这个控制信道。
4.能够使MS接收到小区广播信息。
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- 回复 strong1982
- 25.304
4.1
The purpose of camping on a cell in idle mode is fourfold:
a) It enables the UE to receive system information from the PLMN.
b) When registered and if the UE wishes to establish an RRC connection, it can do this by initially accessing the network on the control channel of the cell on which it is camped.
c) If the PLMN receives a call for the registered UE, it knows (in most cases) the registration area of the cell in which the UE is camped. It can then send a "paging" message for the UE on control channels of all the cells in the registration area. The UE will then receive the paging message because it is tuned to the control channel of a cell in that registration area and the UE can respond on that control channel.
d) It enables the UE to receive cell broadcast services.
5.1.2 Support for PLMN Selection
5.1.2.1 General
On request of the NAS the AS should perform a search for available PLMNs and report them to NAS.
5.1.2.2 UTRA case
The UE shall scan all RF channels in the UTRA bands according to its capabilities to find available PLMNs. On each carrier, the UE shall search for the strongest cell and read its system information, in order to find out which PLMN the cell belongs to. If the UE can read one or several PLMN identities in the strongest cell, each found PLMN (see the PLMN reading in [4]) shall be reported to the NAS as a high quality PLMN (but without the RSCP value), provided that the following high quality criterion is fulfilled:
1. For an FDD cell, the measured primary CPICH RSCP value shall be greater than or equal to -95 dBm.
2. For a TDD cell, the measured P-CCPCH RSCP shall be greater than or equal to -84 dBm.
Found PLMNs that do not satisfy the high quality criterion, but for which the UE has been able to read the PLMN identities are reported to the NAS together with the CPICH RSCP value for UTRA FDD cells and P-CCPCH RSCP for UTRA TDD cells. The quality measure reported by the UE to NAS shall be the same for each PLMN found in one cell.
The search for PLMNs on the rest of the carriers may be stopped on request of the NAS. The UE may optimise this search by using stored information of carrier frequencies and optionally also information on cell parameters, e.g. scrambling codes, from previously received measurement control information elements.
Once the UE has selected a PLMN, the cell selection procedure shall be performed in order to select a suitable cell of that PLMN to camp on.
5.2 Cell selection and reselection in idle mode
5.5 Location Registration
In the UE, the AS shall report registration area information to the NAS.
If the UE reads more than one PLMN identity in the current cell, the UE shall report the found PLMN identities that make the cell suitable in the registration area information to NAS.
The non-access part of the location registration process is specified in [5].
Actions for the UE AS upon reception of Location Registration reject are specified in [9] and [16].
- 回复 strong1982
- 23.122
2 General description of idle mode
When an MS is switched on, it attempts to make contact with a public land mobile network (PLMN). The particular PLMN to be contacted may be selected either automatically or manually.
The MS looks for a suitable cell of the chosen PLMN and chooses that cell to provide available services, and tunes to its control channel. This choosing is known as "camping on the cell". The MS will then register its presence in the registration area of the chosen cell if necessary, by means of a location registration (LR), GPRS attach or IMSI attach procedure.
If the MS loses coverage of a cell, or find a more suitable cell, it reselects onto the most suitable cell of the selected PLMN and camps on that cell. If the new cell is in a different registration area, an LR request is performed.
If the MS loses coverage of a PLMN, either a new PLMN is selected automatically, or an indication of which PLMNs are available is given to the user, so that a manual selection can be made.
Registration is not performed by MSs only capable of services that need no registration
The idle mode tasks can be subdivided into 4 processes:
- PLMN selection;
- Cell selection and reselection;
- Location registration;
- CTS fixed part selection (A/Gb mode only).
4.4.2 Registration on a PLMN
The MS shall perform registration on the PLMN if the MS is capable of services which require registration. In both automatic and manual modes, the concept of registration on a PLMN is used. An MS successfully registers on a PLMN if:
a) The MS has found a suitable cell of the PLMN to camp on; and
b) An LR request from the MS has been accepted in the registration area of the cell on which the MS is camped (see table 1).
4.4.3 PLMN selection
The registration on the selected PLMN and the location registration are only necessary if the MS is capable of services which require registration. Otherwise, the PLMN selection procedures are performed without registration.
4.4.3.1 At switch on or recovery from lack of coverage
At switch on, or following recovery from lack of coverage, the MS selects the registered PLMN or equivalent PLMN (if it is available) using all access technologies that the MS is capable of and if necessary (in the case of recovery from lack of coverage, see clause 4.5.2) attempts to perform a Location Registration.
4.5 Location registration process
4.5.2 Initiation of Location Registration
4.5.3 Periodic Location Registration
4.5.4 IMSI attach/detach operation
4.5.5 No Suitable Cells In Location Area
If during location registration the LR response "No Suitable Cells In Location Area" is received:
The MS shall attempt to find another LA of the same PLMN on which it received the LR response. If the MS is able to find another LA it shall attempt registration. If the MS is unable to find an LA the PLMN Automatic or Manual Mode Selection Procedure of clause 4.4.3.1 shall be followed, depending on whether the MS is in automatic or manual mode.
- 回复 strong1982
- 位置登记----位置登记是指网络保持跟踪移动台实际所处的位置并存储位置信息。通常位置信息存储在称为位置寄存器的功能实体中，即存储在HLR和VLR中，位置登记主要包括下述过程：位置更新,位置删除,周期性位置更新,IMSI分离/附着。
位置更新：移动台在开机或移动过程中,若收到的位置区识别码与移动台存储的位置识别码不一致，则发出位置更新请求，通知网络需更新移动台的位置识别码。
位置删除：当移动台移动到一个新的位置区后,网络确认移动台在当前访问的VLR中重新登记后，将从原来的VLR中删除该移动台的相关信息。
周期性位置更新：处于等待状态且位置稳定的移动台，网络将以适当的时间间隔周期性地令其进行位置更新。
IMSI分离/附着：使移动台能通知网络,它们进入开机/关机或用户识别卡取出/插入状态.