GPRS Iu 模式下的移动管理状态介绍 (Iu mode Mobility Management States)

Iu mode Mobility Management States
Iu 模式下的 GPRS 移动管理状态介绍

 

1.PMM-DETACHED State

In PMM-DETACHED State, there is no communication between MS and 3G-SGSN.
The MS and SGSN contexts hold no valid location or routing information for the MS. 
The MS MM state machine does not react on system information related to the 3G-SGSN.
The MS is not reachable by a 3G-SGSN, as the MS location is not known.

In order to establish MM contexts in the MS and the SGSN,the MS shall perform the GPRS Attach procedure.
When the PS signalling connection is established between the MS and the 3G-SGSN for performing GPRS attach procedure,the state changed to PMM-CONNECTED in the MS and the 3G-SGSN.
The PS signalling connection is made up of two parts : an RRC connection and an Iu connection.

分组移动管理-分离 状态

在该状态下,移动台与3G-GPRS服务支撑节点之间没有任何的通信.
移动台与支撑节点的上下文(移动管理上下文)中没有为移动台保存有效的位置和路由信息.
移动台对与支撑节点相关的任何系统信息做出响应.
由于移动台的位置不可知,所以对3G-服务支撑节点而言,移动台是不可到达的.

为了在移动台和服务支撑节点中建立移动管理上下文,移动台需要执行GPRS附着规程.
当移动台与支撑节点之间建立起分组信令连接并执行GPRS附着规程后,移动台和支撑节点中的移动管理状态
就转变为分组移动管理-连接状态.
分组信令连接由无线资源控制连接 和 Iu 连接两部分组成.

2.PMM-IDLE State

The MS location is known in the SGSN with an accuracy of a  routing area.
Paging is needed in order to reach the MS.
The MS and the SGSN have established MM contexts.

The MS shall perform a routing area update if the RA changes.
Signalling towards the HLR is needed if the SGSN does not have an MM context for the MS.

The Ms and the SGSN shall enter the PMM-CONNECTED state when the PS signalling connection is established between the MS and the 3G-SGSN.

GPRS detach changes the state to PMM-DETACHED.
The 3G-SGSN may perform an  implicit  GPRS detach  any time after the MS reachable timer expiry.
The MS's MM context may be deleted,preferable after a certain time(Implementation dependent).
The HLR may be informed about the deletion(Purge function).

分组移动管理-空闲 状态

移动台所在路由区的信息存储在GPRS服务支撑节点.
要到达某个移动台需要发起寻呼流程.在移动台和支撑节点中已经建立起了移动管理上下文.

如果移动台移动到不同的路由区,则要发起路由区更新规程.如果新路由区的支撑节点中不包含有对应移动台的移动管理上下文,则需要向归属位置寄存器发送信令.

当MS 与 SGSN 之间建立了信令连接,则移动台与SGSN 中的移动管理状态将进入 分组移动管理-连接状态.

GPRS 分离会将状态改变为 分组移动管理-分离 状态.
在任何时候当移动台的可到达定时器超时后,服务支撑节点将发起GPRS 隐式分离.
此时,移动台中的移动管理上下文可以被删除,也可以根据实现保存一定是时间后,再进行删除.
如果执行清除规程,则要通知归属位置寄存器.

3.PMM-CONNECTED State

The MS location is known in the 3g-SGSN with an accuracy of a serving RNC.
In the PMM-CONNECTED state,the MS location is tracked by the serving RNC.
The MS performs routing area update procedure when RAI in the MM system information changes.

When an MS and a 3G-SGSN in PMM-CONNECTED state,the signalling connection is established
 between the MS and the 3G-SGSN.
In the 3G-SGSN,the signalling connection release or failed downlink transfer with the cause
"IMSI unknown in serving RNC" changes state to PMM-IDLE.

The MS shall enter the PMM-IDLE state when its PS signalling connection to  the 3G-SGSN has been released or broken.This release or failure explicitly indicated by the RNC to MS or detected by the MS
when RRC connection failed.The radio connection shall be released if a URA update fails because of 
" RRC connection not established" or if the URA update timer expires while the MS is out of the coverage.

After a signalling procedure(e.g. routing area update),the 3G-SGSN may decide to release PS signalling connection,after which the state is changed to PMM-IDLE.

分组移动管理-连接

在 分组移动管理-连接 状态下,3G-GPRS 服务支撑节点保存移动台所属的服务无线网络控制器信息.
移动台的位置由无线网络控制器跟踪.当移动管理系统中的路由区标识发生改变,移动台将执行路由区更新规程.

当移动台和3G-SGSN 处于分组移动管理-连接 状态,则说明在移动台与 3G-SGSN 之间已经建立了信令连接.
在3G-SGSN 中当出现 "IMSI 不可在服务RNC中的不可识别" 的情况发生时,信令连接将被释放.

移动台将在他的分组信令连接到3G-SGSN 被释放或被破坏的时候,将状态转为 分组移动管理-空闲 状态.
这种连接被释放或破坏的情况可以由RNC 显示的通知MS,也可以由MS 在RRC 连接失败的时候自己检测出来.
当用户注册区更新失败或由于超出覆盖范围而引起用户注册区更新定时器超时,无线连接将被释放.

当执行完一个信令规程,3G-SGSN有可能要决定释放一个分组信令连接,在该连接释放后,移动管理状态转变为
分组移动管理-空闲 状态.