6.13 Intersystem Change系统间改变

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An intersystem change takes place when an MS changes between Iu mode and A/Gb mode of operation by the Routeing Area Update procedure or by PS handover. A prerequisite for an intersystem change is that the MS is GPRS-attached. The transition of the mobility management states is as specified for the corresponding mobility management procedures.
There is no transition of the session management states at an intersystem change.
   一个系统间改变是在以下场景中产生，MS发生了Iu模式到A/Gb模式操作的改变，并且是由一个RAU流程或PS handover流程所触发的。一个系统间改变的前提条件是MS已经GPRS附着了。移动性管理的状态转变由相应的移动性管理流程来指明。

   在系统间改变的流程中，不会发生会话管理状态的转变。

6.13.1 Intra SGSN Intersystem Change
An SGSN that supports both the Gb and Iu PS interfaces may support an intra-SGSN intersystem change if the radio access technology nodes serving the MS before and after the intersystem change are both served by this SGSN.
    一个同时支持Gb和Iu PS接口的SGSN可以支持一个intra-SGSN的系统间改变---当之前和之后为MS提供服务的无线接入技术节点由同一个SGSN服务的时候。
6.13.1.1 Iu mode to A/Gb mode Intra SGSN Change
6.13.1.1.1 Iu mode to A/Gb mode Intra SGSN Change using Gn/Gp
The intersystem change from Iu mode to A/Gb mode takes place when an MS changes from UTRAN or GERAN Iu mode to A/Gb mode. Depending on the PMM state before the intersystem change and whether the RA is changed or not, one of the following procedures is initiated by the MS:
- When an MS in PMM IDLE state changes to the A/Gb mode without changing the RA, the MS shall follow the selective RA update procedures, see clause "Selective RA Update".
- When an MS in PMM IDLE state changes to the A/Gb mode and the RA changes, the MS shall initiate the GPRS RA update procedure, see clause "Intra SGSN Routeing Area Update".
- When an MS in PMM CONNECTED state changes to the A/Gb mode, the MS shall initiate the GPRS RA update procedure independent of whether the RA has changed or not. The RA update procedure is either combined RA / LA update or only RA update.
  从Iu模式到A/Gb模式的系统间改变，是在MS发生了从UTRAN或GERAN Iu模式到A/Gb模式的改变时产生的。根据在系统间改变发生之前的PMM状态以及RA是否改变，以下流程之一将由MS发起：
- 当MS在PMM-IDLE状态变更到A/Gb模式并且没改变RA,MS应执行选择性的RAU流程，参考章节“选择性RA更新”。
- 当MS在PMM-IDLE状态变更到A/Gb模式并且RA改变了，MS应发起GPRS RAU流程，参考章节“Intra SGSN RAU".
- 当MS在PMM-CONNECTED状态变更到A/Gb模式,不管有没有发生RA变化,MS都应发起一个GPRS RAU流程.这个RAU流程或者是一个联合的RA/LAU,或者只是一个RAU.
A combined RA / LA update takes place in network operation mode I when the MS enters a new RA or when a GPRS-attached MS performs IMSI attach. The MS sends a Routeing Area Update Request message indicating that an LA update may also need to be performed, in which case the SGSN forwards the LA update to the VLR. This concerns only idle mode (see TS 23.122 [7b]), as no combined RA / LA updates are performed during a CS connection. In the context of this specification, the terms RNS or RNC refer also to a GERAN BSS or BSC (respectively) when serving an MS in Iu mode.
  一个联合的RA/LAU发生在网络操作模式I---并且当MS进入了一个新的RA或当一个GPRS附着的MS执行了IMSI附着.MS发送RAU Request消息指示这是一个LAU可能也需要执行,SGSN转发LAU给VLR.这仅和idle模式有关(参考TS23.122),因为在一个CS连接期间没有联合的RA/LAU被执行.本规范中上下文的描述中,RNS或RNC的术语也可以相应参考GERAN BSS或BSC---当为一个Iu模式的MS服务时.

Figure 52: Iu mode to A/Gb mode Intra SGSN Change

NOTE: All steps in figure 52 are common for architecture variants using Gn/Gp based interaction with a GGSN and using S4 based interactions with an S GW and P GW. For S4 based interaction with an S GW and P GW, procedure step (A) is defined in clause 6.13.1.1.2.

   注释：在图例52中的所有步骤对于使用Gn/Gp接口和GGSN交互，还是使用S4接口和SGW/PGW交互的架构的都是公共的。基于S4接口和SGW/PGW的交互的步骤A，参考章节6.13.1.1.2。
1) The MS or RAN decides to perform an intersystem change which makes the MS switch to a new cell where A/Gb mode has to be used, and stops transmission to the network.
2) The MS sends a Routeing Area Update Request (old RAI, old P TMSI Signature, Update Type, Voice domain preference and UE's usage setting) message to the 2G+3G SGSN. Update Type shall indicate RA update or combined RA / LA-update or, if the MS wants to perform an IMSI attach, combined RA / LA update with IMSI attached requested. The BSS shall add the Cell Global Identity including the RAC and LAC of the cell where the message was received before passing the message to the 2G+3G SGSN. The UE sets the voice domain preference and UE's usage setting according to its configuration, as described in clause 5.3.15.
   If there is an ongoing emergency bearer service and a Routing Area Update Request is received the Routing Area Update shall be rejected with a cause code indicating that access to GERAN is not allowed.

   1）MS或RAN决定执行一个系统间改变，使得MS能切换到一个新的A/Gb模式下的小区，并且停止传递数据到网络。

  2）MS发送RAU请求（old RAI、old P-TMSI签名、更新类型、语音域优先级和UE的使用设置）消息给2G+3G SGSN。更新类型应指明这个一个RAU或是一个联合的RA/LAY或者，如果MS想执行一个IMSI的附着、带有IMSI附着请求的联合的RA/LAU。BSS应加入CGI（小区全球标识）并包括小区的RAC和LAC到这个接收的消息中，然后再传递给2G+3G SGSN。UE根据它自己的配置，按照章节5.3.15的描述，来设置语音域优先级和它的使用设置。

3) If the MS is PMM CONNECTED state, the 2G+3G SGSN sends an SRNS Context Request (IMSI) message to the SRNS.
4) Upon reception of the SRNS Context Request message, the SRNS starts buffering and stops sending downlink PDUs to the MS. The SRNS responds with an SRNS Context Response (GTP SNDs, GTP SNUs, PDCP-SNDs, PDCP SNUs) message. The GTP sequence numbers are included for each PDP context indicating the next in-sequence downlink GTP-PDU to be sent to the MS and the next in-sequence GTP PDU to be tunnelled to the GGSN. For each active PDP context, which uses lossless PDCP, the SRNS also includes the uplink PDCP sequence number (PDCP SNU) and the downlink PDCP sequence number (PDCP-SND). PDCP SNU is the PDCP sequence number for the next expected in-sequence uplink packet to be received from the MS. PDCP-SND is the PDCP sequence number for the first downlink packet for which successful transmission has not been confirmed. The 2G+3G SGSN shall strip off the eight most significant bits of the passed PDCP sequence numbers, thus converting them to SNDCP N PDU numbers of the respective 2G GPRS PDP contexts.
  3）如果MS是在PMM-CONNECTED状态，2G+3G SGSN发送SRNS Context Request(IMSI)消息给SRNS。

  4)一旦接收到SRNS Context Request消息,SRNS开始缓存并且停止发送下行PDU给MS。SRNS响应一个SRNS Context Response(GTP SNDs、GTP SNUs、PDCP-SNDs、PDCP SNUs）消息。每个PDP上下文都包含了GTP序列号来指示序列中将要发送给MS的下一个下行GTP-PDU，以及序列中下一个将要发送给GGSN被封装进隧道的GTP PDU。对每一个active的PDP上下文，如使用了无损PDCP，SRNS也应包含上行的PDCP序列号(PDCP SNU即Sequence Number Uplink)以及下行PDCP序列号(PDCP-SND即Sequence Number Downlink)。PDCP SNU是一个PDCP序列号，表示的是下一个期望的从MS接收的有序的上行数据报文。PDCP-SND是一个PDCP序列号，表示的是第一个成功传递但还没有被确认的下行数据包。2G+3G SGSN应提取已经传递的PDCP序列号的八位最高有效位，将之转换为在2G GPRS PDP上下文中相应的SNDCP N PDU的值。

5) Security functions may be executed.

  5）安全功能可以被执行。
6) If the MS is PMM CONNECTED, the 2G+3G SGSN sends an SRNS Data Forward Command (RAB ID, Transport Layer Address, Iu Transport Association) message to the SRNS. This informs the SRNS that the 2G+3G SGSN is ready to receive data packets. Upon reception of SRNS Data Forward Command message from the 2G+3G SGSN the SRNS shall start the data-forwarding timer.
6a)If Direct Tunnel was established in Iu mode the SGSN sends Update PDP Context Request to the GGSN(s) concerned to establish the GTP tunnel between SGSN and GGSN. The GGSN(s) update the address for User Plane and downlink TEID for data and return an Update PDP Context Response. Otherwise, if there were changes of for example the RAT type that e.g. can be used for charging, the SGSN sends Update PDP Context Request (SGSN Address and TEID, QoS Negotiated, RAT type) message to the GGSN.
  6)如果MS是PMM-CONNECTED状态，2G+3G SGSN发送SRNS Data Forward Command(RAB ID,传输层地址、Iu传输关联）消息给SRNS。这将通知SRNS，2G+3G SGSN已经准备好接收数据报文。一旦从2G+3G SGSN接收到这个消息，SRNS应开始启动数据转发计时器。

6a）如果在Iu模式建立了直接隧道，SGSN发送Update PDP Context Request给关联的GGSN，来建立在SGSN和GGSN之间的GTP隧道。GGSN更新用户面地址和下行数据的TEID并返回Update PDP Context Response消息。除此以外，如果有别的变化，如RAT类型的变化需要用于计费目的，SGSN发送Update PDP Context Request(SGSN地址和TEID、协商的QOS、RAT类型）消息给GGSN。

7) For each RAB indicated by the SRNS Data Forward Command the SRNS starts duplicating and tunnelling the buffered GTP-PDUs back to the 2G+3G SGSN. For each radio bearer which uses lossless PDCP the GTP-PDUs related to transmitted but not yet acknowledged PDCP PDUs are duplicated and tunnelled back to the 2G+3G SGSN together with their related downlink PDCP sequence numbers. The 2G+3G SGSN converts the PDCP sequence numbers to SNDCP sequence number (by stripping off the eight most significant bits of the PDCP sequence numbers).
  7）由SRNS Data Forward Command指明的每一个RAB，SRNS开始将缓存的GTP-PDU复制并且封入隧道发给2G+3G SGSN。对使用了无损PDCP压缩的每一个无线承载，相关的已经传输但还没有得到确认的GTP-PDU，PDCP PDU将被复制并且和他们相关联的PDCP序列号一起通过隧道回传给2G+3G SGSN。2G+3G SGSN将把PDCP序列号转换为SNDCP序列号(通过去除PDCP序列号的最高8位）。

8) The 2G+3G SGSN sends an Iu Release Command message to the SRNS. When the RNC data-forwarding timer has expired, the SRNS responds with an Iu Release Complete message.
  8）2G+3G SGSN发送Iu Release Command消息给SRNS。当RNC转发数据计时器超时，SRNS响应一个Iu Release Complete消息。

9) If the association has to be established i.e. if Update Type indicates combined RA / LA update with IMSI attach requested, or if the LA changed with the routeing area update, then the 2G+3G SGSN sends a Location Update Request (new LAI, IMSI, SGSN Number, Location Update Type) to the VLR. Location Update Type shall indicate IMSI attach if Update Type in step 1 indicated combined RA / LA update with IMSI attach requested. Otherwise, Location Update Type shall indicate normal location update. When the SGSN does not provide functionality for the Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the VLR number is derived from the RAI. When the SGSN provides functionality for Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the SGSN uses the RAI and a hash value from the IMSI to determine the VLR number. The VLR creates or updates the association with the 2G+3G SGSN by storing the SGSN Number.
  9）如果关联需要建立，也就是更新类型指示了带有IMSI附着的联合的RA/LAU请求，或在RAU时发生了LA的变化，那么2G+3G SGSN发送Location Update Request(新LAI、IMSI、SGSN编号、Location Update Type)给VLR。Location Update Type应指示为IMSI附着---如果在步骤1的更新类型指示的是带有IMSI附着请求的联合RA/LAU。除此以外，Location Update Type应指示为一个正常的Location Update。当SGSN不为多个CN节点提供到RAN节点的域内连接功能的话，VLR编号将从RAI获取。当SGSN提供这个功能时，SGSN使用RAI以及从IMSI得到的一个哈希函数来决定VLR编号。VLR通过存储SGSN编号来创建或更新与2G+3G SGSN的关联。

10) If the subscriber data in the VLR is marked as not confirmed by the HLR, the new VLR informs the HLR. The HLR cancels the data in the old VLR and inserts subscriber data in the new VLR:
a)  The new VLR sends an Update Location (new VLR) to the HLR.
b)  The HLR cancels the data in the old VLR by sending Cancel Location (IMSI) to the old VLR.
c)  The old VLR acknowledges with Cancel Location Ack (IMSI).
d)  The HLR sends Insert Subscriber Data (IMSI, subscriber data) to the new VLR.
e)  The new VLR acknowledges with Insert Subscriber Data Ack (IMSI).
f)  The HLR responds with Update Location Ack (IMSI) to the new VLR.
  10)如果VLR上的签约数据标记为未得到HLR的确认，则new VLR要通知HLR。HLR取消在old VLR上的数据并在new VLR插入新的用户签约数据：
a）new VLR发送update location(new VLR)给HLR。
b) HLR发送cancel location(IMSI)消息给old VLR来取消其上的数据。
c）old VLR发送cancel location ack（IMSI)进行确认。
d）HLR发送插入签约用户数据(IMSI,签约数据）给new VLR。
e）new VLR发送insert subscriber data ack(IMSI)进行确认。
f）HLR发送update location ack（IMSI）给new VLR进行响应。
11) The new VLR allocates a new VLR TMSI and responds with Location Update Accept (VLR TMSI) to the 2G+3G SGSN. VLR TMSI is optional if the VLR has not changed.
12) The 2G+3G SGSN validates the MS's presence in the new RA. If due to roaming restrictions or access restrictions the MS is not allowed to be attached in the RA, or if subscription checking fails, the 2G+3G SGSN rejects the routeing area update with an appropriate cause. If all checks are successful, the 2G+3G SGSN updates MM and PDP contexts for the MS. A new P TMSI may be allocated. A logical link is established between the new 2G+3G SGSN and the MS. 2G+3G-SGSN initiates the establishment procedure. A Routeing Area Update Accept (P TMSI, P TMSI Signature, Receive N PDU Number (= converted PDCP SNU), IMS voice over PS Session Supported Indication) message is returned to the MS. Receive N PDU Number contains the acknowledgements for each NSAPI which used lossless PDCP before the start of the update procedure, thereby confirming all mobile-originated N PDUs successfully transferred before the start of the update procedure. If Receive N PDU Number confirms the reception of N PDUs, these N PDUs shall be discarded by the MS. The IMS voice over PS Session Supported Indication is set as described in clause 5.3.8.
   11）new VLR分配一个新的VLR TMSI并且响应location update accept(VLR TMSI)给2G+3G SGSN。VLR TMSI是可选的，如果VLR没有发生变化的话。
  12）2G+3G SGSN验证在新RA中MS的存在性。如果因为漫游限制或接入限制，MS不允许附着到RA，或者如果签约检查失败，则2G+3G SGSN拒绝RAU并给出原因值。如果所有检查都成功，2G+3G SGSN更新MS的MM和PDP上下文。一个新的P-TMSI将被分配。一条逻辑链路将在new 2G+3G SGSN和MS之间建立。2G+3G SGSN发起建立流程。一个RAU accept(P-TMSI、P-TMSI签名、Receive N-PDU Number（=转换的PDCP SNU)，IMS voice over PS会话指示指示）消息将返回给MS。Receive N-PDU Number包含了在更新流程开始之前，使用了无损PDCP的对每个NSAPI的确认，因此确认了在开始更新流程之前所有MS发起的成功传递的N-PDU。如果Receive N-PDU Number确认了对N-PDU的接收，那些N-PDU应被MS丢弃。IMS voice over PS会话指示指示根据5.3.8章节描述设置。
13) The MS acknowledges the new P TMSI by returning a Routeing Area Update Complete (Receive N PDU Number) message to the SGSN. Receive N PDU Number (= converted PDCP SND) contains the acknowledgements for each NSAPI which used lossless PDCP before the start of the update procedure, thereby confirming all mobile-terminated N PDUs successfully transferred before the start of the update procedure. If Receive N PDU Number confirms the reception of N PDUs, these N PDUs shall be discarded by the 2G+3G-SGSN.The MS deducts Receive N PDU Number from PDCP SND by stripping off the eight most significant bits. PDCP SND is the PDCP sequence number for the next expected in-sequence downlink packet to be received in the MS per radio bearer, which used lossless PDCP. The new 2G-SGSN negotiates with the MS for each NSAPI the use of acknowledged or unacknowledged SNDCP regardless whether the SRNS used lossless PDCP or not.
14) The 2G+3G SGSN sends a TMSI Reallocation Complete message to the VLR if the MS confirms the VLR TMSI.
15) The 2G+3G SGSN and the BSS may execute the BSS Packet Flow Context procedure.
   13)MS返回RAU Complete(Receive N-PDU Number）消息给SGSN来确认对新P-TMSI的分配。Receive N-PDU Number（=转换的PDCP SND）包含了更新流程开始之前，使用了无损PDCP的对每个NSAPI的确认，因此确认了在开始更新流程之前所有MS接收的成功传递的N-PDU。如果Receive N-PDU Number确认了对N-PDU的接收，那些N-PDU应被2G+3G SGSN丢弃。MS通过剥离PDCP SND的高8位有效位来得到Receive N-PDU Number。PDCP SND是一个PDCP序列号，用于标识在每个无线承载上，下一个期望在MS上收到的使用了无损PDCP的下行数据报文。New 2G-SGSN和MS为每个NSAPI协商使用确认或非确认SNDCP，而不管之前SRNS是否使用PDCP或没有使用。
  14）2G+3G SGSN发送TMSI Reallocation Complete消息给VLR---如果MS确认了VLR TMSI的话。
  15）2G+3G SGSN以及BSS可执行BSS Packet Flow Context流程。

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In this case, clause 6.13.1.1.1 applies except for steps 6a and 7, as well as section specific general statements stated below.

  在本例中，章节6.13.1.1.1中的流程步骤除了6a和第7步，都适用于本例。因此不再列出，以下至列出不同部分。

Figure 52-2: step 6a for Iu mode to A/Gb mode Intra SGSN Change using S4

NOTE: Steps a) and d) are common for architecture variants with GTP-based S5/S8 and PMIP-based S5/S8. For a PMIP-based S5/S8, procedure step (A1) is defined in TS 23.402 [90]. Steps b) and c) in Figure 52-2 concern GTP-based S5/S8.
  注释：步骤a和d对于使用基于GTP或PMIP的S5/S8接口来说都是公共的。对于基于PMIP的S5/S8，步骤A1在TS23.402描述。步骤b和c在图例52-2中是基于GTP的S5/S8.

a) In this procedure flow the Serving GW is not relocated. If Direct Tunnel was established in Iu mode or if there were changes of for example the RAT type that e.g. can be used for charging, the SGSN sends Modify Bearer Request (SGSN Address and TEID, serving network identity, RAT type) message to the Serving GW.
b) The Serving GW informs the P GW(s) about the change of for example the RAT type that e.g. can be used for charging, by sending the message Modify Bearer Request (Serving GW Address and TEID, RAT type) to the concerned P GW(s). If dynamic PCC is deployed, and RAT type information needs to be conveyed from the P GW to the PCRF, then the P GW sends RAT type information to the PCRF as defined in TS 23.203 [88].
c) Each P GW updates its context field and returns a Modify Bearer Response (MSISDN, P GW address and TEID) message to the Serving GW. MSISDN is included if available in the stored UE context.
   a)在这个流程中,SGW没有被重新选择。如果直接隧道在Iu模式建立或有一些变化例如RAT类型变化可以被用于计费的，SGSN发送Modify Bearer Request（SGSN地址和TEID,服务网络ID，RAT类型）消息给SGW。

  b）SGW通知PGW这个可用于计费目的的变化，例如RAT类型的变化，通过发送Modify Bearer Request（SGW地址和TEID、RAT类型）消息给相关的PGW来告知。如果部署了动态的PCC，并且RAT类型信息需要从PGW传递给PCRF，那PGW将发送RAT类型信息给PCRF，这在TS23.203中定义。

  c）每个PGW更新它的上下文字段并且返回Modify Bearer Response（MSISDN、PGW地址和TEID)消息给SGW。MSISDN如果在存储的UE上下文中有的话也将被包含。

d) The Serving GW updates the address for User Plane and downlink TEID for data and return a Modify Bearer Response (Serving GW address and TEID, P GW address and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN GW(s) for uplink traffic) message.
e) In case Direct Tunnel in Iu mode was not established, for each RAB indicated by the SRNS Data Forward Command the SRNS starts duplicating and tunnelling the buffered GTP-PDUs back to the 2G+3G SGSN. For each radio bearer which uses lossless PDCP the GTP-PDUs related to transmitted but not yet acknowledged PDCP PDUs are duplicated and tunnelled back to the 2G+3G SGSN together with their related downlink PDCP sequence numbers. The 2G+3G SGSN converts the PDCP sequence numbers to SNDCP sequence number (by stripping off the eight most significant bits of the PDCP sequence numbers).
   In case Direct Tunnel in Iu mode was established, the packets are forwarded via the S GW.
   d）SGW更新用户面地址和数据的下行TEID并返回一个Modify Bearer Response(SGW地址和TEID，在PGW上用于上行流量的PGW地址和TEID(基于GTP的S5/S8)或GRE密钥（基于PMIP的S5/S8)）消息给SGSN。

  e）如果Iu模式的直接隧道没有建立，对每个在SRNS Data Forward Command中指明的RAB，SRNS开始将缓存的GTP-PDU进行复制并且通过隧道返回给2G+3G SGSN。对使用了无损PDCP压缩的每一个无线承载，相关的已经传输但还没有得到确认的GTP-PDU，PDCP PDU将被复制并且和他们相关联的PDCP序列号一起通过隧道回传给2G+3G SGSN。2G+3G SGSN将把PDCP序列号转换为SNDCP序列号(通过去除PDCP序列号的最高8位）。

  如果Iu模式的直接隧道建立，数据包将通过SGW被转发。

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6.13.1.2.1 A/Gb mode to Iu mode Intra-SGSN Change using Gn/Gp
The intersystem change from A/Gb mode to Iu mode takes place when a GPRS-attached MS changes from A/Gb mode to GERAN or UTRAN Iu mode. Depending on the GPRS mobility management state before the intersystem change and whether the RA is changed or not, one of the following procedures is initiated by the MS:
  当一个GPRS附着的MS发生了从A/Gb模式到GERAN或UTRAN Iu模式变化的话，则产生了从A/Gb模式到Iu模式的系统间改变。根据在发生系统间改变发生前的GPRS移动性状态以及RA是否变化，下列流程之一将由MS发起：
- When an MS in STANDBY state changes to Iu mode inside the current RA, the MS shall follow the selective RA update procedures, see clause "Selective RA Update".
- When an MS in STANDBY state changes to Iu mode and the RA changes, the MS shall initiate the Iu mode RA update procedure, see clause "Routeing Area Update Procedure".
- When an MS in READY state changes to Iu mode independent of whether the RA has changed or not, the MS shall initiate the Iu mode RA update procedure and afterwards initiate the RABs by the Service Request procedure, see clause "MS Initiated Service Request Procedure". The RA update procedure is either combined RA / LA update or only RA update.
- 当STANDBY状态的MS在当前RA内变更到了Iu模式，则MS应发起选择性RAU流程，参考"Selective RA Update".
- 当STANDBY状态的MS变更到Iu模式并发生了RA的改变，MS应发起Iu模式RAU流程，参考章节“RAU”。
- 当READY状态的MS变更到Iu模式，不管RA有没有变化，MS都应发起Iu模式的RAU流程，然后发起service request流程来建立RAB，参考章节"MS Initiated Service Request Procedure".RAU或者是联合的RA/LAU或仅为RAU。
If the network operates in mode I, an MS that is both PS-attached and CS-attached shall perform the Combined RA / LA Update procedure. This concerns only idle mode (see TS 23.122 [7b]), as no combined RA / LA updates are performed during a CS connection. In the context of this specification, the terms RNS or RNC refer also to a GERAN BSS or BSC (respectively) when serving an MS in Iu mode.
   如果网络工作模式为I，一个同时PS和CS附着的MS应执行联合的RA/LAU流程。仅和idle模式有关(参考TS23.122),因为在一个CS连接期间没有联合的RA/LAU被执行.本规范中上下文的描述中,RNS或RNC的术语也可以相应参考GERAN BSS或BSC---当为一个Iu模式的MS服务时.

Figure 53: A/Gb mode to Iu mode Intra SGSN Change

1) The MS or the RAN decides to perform an intersystem change which makes the MS switch to a new cell where Iu mode has to be used, and stops transmission to the network.
2) The MS initiates an RRC connection establishment and sends a Routeing Area Update Request (P TMSI, Old RA, Old P TMSI Signature, Update Type, CM, Voice domain preference and UE's usage setting) message to the combined 2G+3G SGSN. Update Type shall indicate RA update or combined RA / LA update or, if the MS wants to perform an IMSI attach, combined RA / LA update with IMSI attach requested and also if the MS has a follow on request, i.e. if there is pending uplink traffic (signalling or data). The SGSN may use, as an implementation option, the follow-on request indication to release or keep the Iu connection after the completion of the RA update procedure. The SRNS shall add an identifier of the area where the message was received before passing the message to the 2G+3G SGSN. The 2G+3G SGSN stops transmission of N PDUs to the MS. The UE sets the voice domain preference and UE's usage setting according to its configuration, as described in clause 5.3.15.
   1)MS或RAN决定执行系统间改变，使得MS切换到一个Iu模式的新小区，并停止传输数据到网络侧。

  2）MS发起RRC连接建立以及发送RAU Request(P-TMSI、old RA、old P-TMSI签名、更新类型、CM、语音域优先级和UE的使用设置）消息给联合的2G+3G SGSN。更新类型应指明这是一个RAU还是一个联合的RA/LAU，或者，如果MS想执行一个IMSI的附着、带有IMSI附着请求的联合的RA/LAU，并且呢MS还带上了follow on request这个flag来指示有一个pending的上行流量（信令或数据）。SGSN可以使用，做为一个实现的选项，这个follow on request的指示可以用于决定在完成RAU流程之后是否保持或释放Iu连接。SRNS应在收到的消息中加上区域ID，然后再传送给2G+3G SGSN。2G+3G SGSN停止到MS的N-PDU的传输。UE根据它自己的配置，按照章节5.3.15的描述，来设置语音域优先级和它的使用设置。

3) Security functions may be executed.
4) If the association has to be established i.e. if Update Type indicates combined RA / LA update with IMSI attach requested, or if the LA changed with the routeing area update, the 2G+3G SGSN sends a Location Update Request (new LAI, IMSI, SGSN Number, Location Update Type) to the VLR. Location Update Type shall indicate IMSI attach if Update Type in step 1 indicated combined RA / LA update with IMSI attach requested. Otherwise, Location Update Type shall indicate normal location update. When the SGSN does not provide functionality for the Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the VLR number is derived from the RAI. When the SGSN provides functionality for Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the SGSN uses the RAI and a hash value from the IMSI to determine the VLR number. The VLR creates or updates the association with the 2G+3G SGSN by storing SGSN Number. In networks that support network sharing, the Location Update Request includes the identity of the selected core network operator if the SGSN has received this information from the RNS, as described in TS 23.251 [83].
  3）安全功能可以执行。
  4）如果关联需要建立，也就是更新类型指示了带有IMSI附着的联合的RA/LAU请求，或在RAU时发生了LA的变化，那么2G+3G SGSN发送Location Update Request(新LAI、IMSI、SGSN编号、Location Update Type)给VLR。Location Update Type应指示为IMSI附着---如果在步骤1的更新类型指示的是带有IMSI附着请求的联合RA/LAU。除此以外，Location Update Type应指示为一个正常的Location Update。当SGSN不为多个CN节点提供到RAN节点的域内连接功能的话，VLR编号将从RAI获取。当SGSN提供这个功能时，SGSN使用RAI以及从IMSI得到的一个哈希函数来决定VLR编号。VLR通过存储SGSN编号来创建或更新与2G+3G SGSN的关联。在网络侧支持网络共享时，Location Update Request包括了选择的核心网络运营商的IE（如果SGSN从RNS收到了这些信息的话)在TS23.251描述）。
5) If the subscriber data in the VLR is marked as not confirmed by the HLR, the new VLR informs the HLR. The HLR cancels the data in the old VLR and inserts subscriber data in the new VLR:
a) The new VLR sends an Update Location (new VLR) to the HLR.
b) The HLR cancels the data in the old VLR by sending Cancel Location (IMSI) to the old VLR.
c) The old VLR acknowledges with Cancel Location Ack (IMSI).
d) The HLR sends Insert Subscriber Data (IMSI, subscriber data) to the new VLR.
e) The new VLR acknowledges with Insert Subscriber Data Ack (IMSI).
f) The HLR responds with Update Location Ack (IMSI) to the new VLR.
   5)如果VLR上的签约数据标记为未得到HLR的确认，则new VLR要通知HLR。HLR取消在old VLR上的数据并在new VLR插入新的用户签约数据：
a）new VLR发送update location(new VLR)给HLR。
b) HLR发送cancel location(IMSI)消息给old VLR来取消其上的数据。
c）old VLR发送cancel location ack（IMSI)进行确认。
d）HLR发送插入签约用户数据(IMSI,签约数据）给new VLR。
e）new VLR发送insert subscriber data ack(IMSI)进行确认。
f）HLR发送update location ack（IMSI）给new VLR进行响应。
6) The new VLR allocates a new VLR TMSI and responds with Location Update Accept (VLR TMSI) to the 2G+3G SGSN. VLR TMSI is optional if the VLR has not changed.
7) The 2G+3G SGSN validates the MS's presence in the new RA. If due to roaming restrictions or access restrictions the MS is not allowed to be attached in the RA, or if subscription checking fails, the 2G+3G SGSN rejects the routeing area update with an appropriate cause. If the network supports the MOCN configuration for network sharing, the SGSN may, if the MS is not a 'Network Sharing Supporting MS', in this case decide to initiate redirection by sending a Reroute Command to the RNS, as described in TS 23.251 [83] instead of rejecting the routeing area update. If all checks are successful, the 2G+3G SGSN updates MM and PDP contexts for the MS. A new P TMSI may be allocated. A Routeing Area Update Accept (P TMSI, P TMSI Signature, IMS voice over PS Session Supported Indication, Emergency Service Support) message is returned to the MS. The 2G+3G-SGSN derives for this intersystem change the corresponding PDCP sequence numbers from the N PDU sequence numbers stored in the SGSN PDP contexts by adding eight most significant bits "1". These PDCP sequence numbers are stored in the SGSN PDP contexts. The IMS voice over PS Session Supported Indication is set as described in clause 5.3.8.
   The Emergency Service Support indicator shall be included when going to UTRAN to inform the MS that Emergency PDP contexts are supported, i.e. the MS is allowed to request activation of emergency PDP context when needed.
  6)new VLR分配一个新的VLR TMSI并且响应location update accept(VLR TMSI)给2G+3G SGSN。VLR TMSI是可选的，如果VLR没有发生变化的话。
7）2G+3G SGSN验证在新RA中MS的存在性。如果因为漫游限制或接入限制，MS不允许附着到RA，或者如果签约检查失败，则2G+3G SGSN拒绝RAU并给出原因值。如果网络支持网络共享的MOCN配置，SGSN可以，如果MS是一个不支持网络共享的MS，在这个case里决定发送reroute command给RNS来执行重定向来代替拒绝RAU，这在TS23.251描述。 如果所有检查都成功，2G+3G SGSN更新MS的MM和PDP上下文。一个新的P-TMSI将被分配。一个RAU accept(P-TMSI、P-TMSI签名、IMS voice over PS会话指示指示、紧急业务支持）消息将返回给MS。2G+3G SGSN为这个系统间改变，从存储在SGSN PDP上下文的N-PDU序列号中提取出相应的PDCP序列号，方式是加入8位有效位1。这些PDCP序列号将存储在SGSN PDP上下文中。IMS voice over PS会话指示指示根据5.3.8章节描述设置。
  当进入到UTRAN时应包含紧急业务支持指示，来通知MS关于紧急PDP上下文支持的能力，也就是MS允许在需要的时候请求紧急PDP上下文的激活。  
8) The MS acknowledges the new P TMSI by returning a Routeing Area Update Complete message to the SGSN.
9) The 2G+3G SGSN sends a TMSI Reallocation Complete message to the VLR if the MS confirms the VLR TMSI.
10)If the MS has pending uplink data or signalling, it shall send a Service Request (P TMSI, RAI, CKSN, Service Type) message to the SGSN. Service Type specifies the requested service. Service Type shall indicate one of the following: Data or Signalling.
   8)MS返回RAU Complete消息给SGSN来确认对新P-TMSI的分配。
   9) 2G+3G SGSN发送TMSI Reallocation Complete消息给VLR---如果MS确认了VLR TMSI的话。
   10)如果MS有pending的上行数据或信令，它应发送一个service request(P-TMSI、RAI、CKSN、Service Type）消息给SGSN。Service Type指明了请求的服务。Service Type的值应为数据或信令。  
11) The 2G+3G SGSN requests the SRNS to establish a radio access bearer by sending a RAB Assignment Request (RAB ID(s), QoS Profile(s), GTP SNDs, GTP SNUs, PDCP SNUs, UE-AMBR, MSISDN, APN, Charging characteristics) message to the SRNS. If Direct Tunnel is established the SGSN provides to the RNC the GGSN's Address for User Plane and TEID for uplink data. The PDCP sequence numbers are derived from the N PDU sequence numbers and stored in the PDP contexts in step 7). The SRNS sends a Radio Bearer Setup Request (PDCP SNUs) message to the MS. The MS responds with a Radio Bearer Setup Complete (PDCP SNDs) message. The SRNS responds with a RAB Assignment Response message. MSISDN, APN and Charging characteristics are optional parameters and only transferred if SGSN supports SIPTO at Iu-ps.
NOTE: The NSAPI value is carried in the RAB ID IE.
    11)2G+3G SGSN发送RAB Assignment Request（RAB ID、QOS profile、GTP SNDs、GTP SNUs、PDCP SNUs、UE-AMBR、MSISDN、APN、计费特征）消息给SRNS来请求SRNS建立一个RAB。如果直接隧道建立，SGSN给RNC提供GGSN的用于上行数据的用户面地址和TEID。PDCP序列号从N-PDU序列号派生出来并存储在步骤7的PDP上下文中。SRNS发送Radio Bearer Setup Request(PDCP SNUs)消息给MS.MS发送Radio Bearer Setip Complete（PDCP SNDs）消息做为响应。SRNS然后响应一个RAB Assignment Response消息给SGSN。MSISDN、APN和计费特征是仅当在Iu-PS，SGSN支持SIPTO的时候的可选参数。
   注释：NSAPI的值包含在RAB ID这个IE（信息元素）中。
11a) If the SGSN established Direct Tunnel it shall send Update PDP Context Request to the GGSN(s) concerned and include the RNC's Address for User Plane, downlink TEID for data and DTI to instruct the GGSN(s) to apply Direct Tunnel specific error handling as described in clause 13.8. The GGSN(s) update the Address for User Plane and TEID for downlink data and return an Update PDP Context Response. Otherwise, if there were changes of for example the RAT type that e.g. can be used for charging, the SGSN sends Update PDP Context Request (SGSN Address and TEID, QoS Negotiated, RAT type) message to the GGSN.
   11a)如果SGSN建立了直接隧道，它应发送Update PDP Context Request消息给相关的GGSN并且包含RNC的用户面地址和TEID，以及DTI来指示GGSN应用直接隧道，错误处理流程在章节13.8描述。GGSN更新下行数据用户面地址和TEID，并返回Update PDP Context Response。除此以外，如果有别的变化，如RAT类型的变化需要用于计费目的，SGSN发送Update PDP Context Request(SGSN地址和TEID、协商的QOS、RAT类型）消息给GGSN。
12) Traffic flow is resumed between the 2G+3G SGSN and the SRNS. N-PDUs that were already sent to the MS in acknowledged mode SNDCP and that are not yet acknowledged by the MS are tunnelled by the 2G+3G SGSN to the SRNS together with their related N-PDU number (SNDCP sequence number). No PDCP sequence numbers shall be indicated for these N-PDUs. The SRNS shall discard all N PDUs with N PDU sequence numbers older than the eight least significant bits of PDCP-SND received from the MS. Other N PDUs shall be transmitted to the MS. The MS shall discard all N PDUs with sequence numbers older than the eight least significant bits of the PDCP SNU received from the SRNS. All other N PDUs shall be transmitted to the SRNS. The SRNS negotiates with the MS for each radio bearer the use of lossless PDCP or not regardless whether the old 2G-SGSN used acknowledged or unacknowledged SNDCP for the related NSAPI or not.
13) The traffic flow is resumed between the SRNS and the MS.
   12）数据流量将在2G+3G SGSN和SRNS之间重新获取。在确认模式SNDCP下已经发给MS但还有没有得到确认的N-PDUs将和它们相应的N-PDU number(SNDCP序列号）一起被封装到隧道中由2G+3G SGSN传递给SRNS。没有PDCP序列号来指示这些N-PDU。SNRS将从MS收到的PDCP-SND的低8位有效位和N-PDU序列号进行比较，将较老的N-PDU序列号的所有N-PDU丢弃。MS应将从SRNS收到的PDCP SNU的低八位有效位和N-PDU序列号进行比较，并将所有较老的N-PDU序列号的所有N-PDU丢弃。所有其他的N-PDU应被传递到SRNS。SRNS和MS为每一个无线承载来协商是否使用或不使用无损PDCP，而不管old 2G-SGSN为相关的NSAPI是否使用了确认或非确认模式的SNDCP。
   13）数据流量将在SRNS和MS之间重新获取。

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In this case, clause 6.13.1.2.1 applies except for step 11, as well as clause-specific general statements stated below.
  在本例中，章节6.13.1.2.1中的流程步骤除了第11步，都适用于本例。因此不再列出，以下至列出不同部分。

Figure 53-2: step 11 for A/Gb mode to Iu mode Intra-SGSN Change using S4

NOTE: Steps a) and d) are common for architecture variants with GTP-based S5/S8 and PMIP-based S5/S8. For a PMIP-based S5/S8, procedure step (A1) is defined in TS 23.402 [90]. Steps b) and c) in Figure 53-2 concern GTP-based S5/S8.
   注释：步骤a和d对于使用基于GTP或PMIP的S5/S8接口来说都是公共的。对于基于PMIP的S5/S8，步骤A1在TS23.402描述。步骤b和c在图例53-2中是基于GTP的S5/S8.

a) If the SGSN established Direct Tunnel it shall send Modify Bearer Request (RNC Address and TEID, serving network identity, RAT type) message to the Serving GW and include the RNC's Address for User Plane, downlink TEID for data and DTI to instruct the Serving GW to apply Direct Tunnel specific error handling as described in clause 13.8. Otherwise, if there were changes of for example the RAT type that e.g. can be used for charging, the SGSN shall send Modify Bearer Request (SGSN Address and TEID, serving network identity, RAT type) message to the Serving GW and include the SGSN's Address for User Plane, downlink TEID for data.
   a)如果直接隧道建立，SGSN发送Modify Bearer Request（RNC地址和TEID,服务网络ID，RAT类型）消息给SGW并且包含了RNC用户面地址、下行数据的TEID和DTI来指示SGW要应用直接隧道，错误处理流程在13.8章节描述。除此以外，如果有一些变化例如RAT类型变化可以被用于计费的，SGSN发送Modify Bearer Request（SGSN地址和TEID,服务网络ID，RAT类型）消息给SGW并且应包含用户数据的下行TEID和用户面SGSN地址。  

b) The Serving GW informs the P GW(s) about the change of for example the RAT type that e.g. can be used for charging, by sending the message Modify Bearer Request (Serving GW Address and TEID, RAT type) to the concerned P GW(s). If dynamic PCC is deployed, and RAT type information needs to be conveyed from the P GW to the PCRF, then the P GW sends RAT type information to the PCRF as defined in TS 23.203 [88].
   b)SGW通知PGW这个可用于计费目的的变化，例如RAT类型的变化，通过发送Modify Bearer Request（SGW地址和TEID、RAT类型）消息给相关的PGW来告知。如果部署了动态的PCC，并且RAT类型信息需要从PGW传递给PCRF，那PGW将发送RAT类型信息给PCRF，这在TS23.203中定义。

c) Each P GW updates its context field and returns a Modify Bearer Response (MSISDN, P GW address and TEID) message to the Serving GW. MSISDN is included if available in the stored UE context.
   c）每个PGW更新它的上下文字段并且返回Modify Bearer Response（MSISDN、PGW地址和TEID)消息给SGW。MSISDN如果在存储的UE上下文中有的话也将被包含。

d) The Serving GW updates the Address for User Plane and TEID for downlink data and return a Modify Bearer Response (Serving GW address and TEID, P GW address and TEIDs (for GTP-based S5/S8) or GRE keys (for PMIP-based S5/S8) at the PDN GW(s) for uplink traffic) message.
    d）SGW更新用户面地址和数据的下行TEID并返回一个Modify Bearer Response(SGW地址和TEID，在PGW上用于上行流量的PGW地址和TEID(基于GTP的S5/S8)或GRE密钥（基于PMIP的S5/S8)）消息给SGSN。

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The MS shall use the following procedures when in STANDBY or PMM IDLE state.
Note that upon expiry of the periodic RA update timer, the MS shall carry out the periodic routeing area update procedure.
    MS应在STANDBY或PMM-IDLE状态的时候使用下面的流程。
    注意到一旦周期性RAU计时器超时，MS应发起周期性RAU流程。

6.13.1.3.1 Uplink Signalling or Data Transmission
In STANDBY or PMM IDLE state the MS shall not perform an RA update procedure until uplink data or signalling information is to be sent from the MS.
If the MS is in the same mode (A/Gb mode or Iu mode) as when it last sent data or signalling, the procedures defined for that mode shall be followed. This shall be the sending of an LLC PDU in A/Gb mode, or for example sending of a Service Request message in Iu mode.
If the MS is in a different mode (A/Gb mode or Iu mode) as when it last sent data or signalling, the RA update procedure shall be performed before the sending of data or signalling. The RA update procedure needs not be performed if the signalling message is a power-off detach.
在STANDBY或PMM-IDLE状态下,MS不应执行RAU流程直到有上行数据或信令消息发送。
  如果MS和它上一次发送数据或信令时，处在相同的模式下（A/Gb模式或Iu模式），那就按照这个模式定义的流程来执行。例如A/Gb模式下是发送LLC PDU，或者Iu模式下是发送service request消息。
如果MS和它上一次发送数据或信令时，处在不相同的模式下（A/Gb模式或Iu模式），RAU流程应在发送数据或信令之前执行。当然，如果这个信令消息是一个关机的detach，则不用执行RAU。

6.13.1.3.2 Downlink Signalling or Data Transmission
If the SGSN receives data for an MS in STANDBY or PMM IDLE state or, if the SGSN uses S4 and receives a Downlink Data Notification from the S GW, the SGSN shall page in the RA where the MS is located. This may include both A/Gb mode and Iu mode cells.
  如果接收到了一个STANDBY或PMM-IDLE状态MS发过来的数据，或者，如果SGSN使用S4接口并从SGW收到了一个下行数据通知，SGSN应在MS所在的RA进行寻呼。这可以既包含A/Gb模式也包含Iu模式的小区。
If the MS receives this page in the same mode (A/Gb mode or Iu mode)as when it last sent data or signalling, the procedures defined for that mode shall be followed. This shall be the sending of an LLC PDU in a cell where the MS has to use A/Gb mode or, for example, sending of a Service Request message in a cell where the MS has to use Iu mode. When receiving such trigger from the RAN, if the S4-SGSN has no S4/S12 downlink user plane TEIDs for the UE, it sends Modify Bearer Request (S4/S12 downlink user plane TEIDs and IP address) to the S GW, which establishes the downlink user plane towards the S4-SGSN or S12 RNC.
If the MS receives this page in a different mode (A/Gb mode or Iu mode) as when it last sent data or signalling, the RA update procedure shall be performed. The SGSN shall accept this RAU as a valid response.
   如果MS和它上一次发送数据或信令时，与收到的这个寻呼在相同的模式（A/Gb模式或Iu模式）,例如A/Gb模式下是发送LLC PDU，或者Iu模式下是发送service request消息。当收到从RAN来的这些触发，如果S4-SGSN没有关于这个UE的S4/S12接口的下行用户面TEID，它将发送Modify Bearer Request(S4/S12下行用户面TEID和IP地址）给SGW，来建立到S4-SGSN或S12 RNC的下行用户面。
  如果MS和它上一次发送数据或信令时，处在不相同的模式下（A/Gb模式或Iu模式），RAU流程应执行。SGSN应将这个RAU做为一个正确的响应来接收。   

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6.13.2.1  Iu mode to A/Gb mode Inter-SGSN Change
6.13.2.1.1  Iu mode to A/Gb mode Inter-SGSN Change using Gn/Gp
An inter-SGSN inter-system change from Iu mode to A/Gb mode takes place when an MS in PMM IDLE or PMM CONNECTED state changes from UTRAN or GERAN Iu mode to A/Gb mode and the A/Gb mode radio access node serving the MS is served by a different SGSN. In this case, the RA changes. Therefore, the MS shall initiate a A/Gb mode RA update procedure. The RA update procedure is either combined RA / LA update or only RA update. These RA update cases are illustrated in Figure 54. In the context of this specification, the terms RNS or RNC refer also to a GERAN BSS or BSC (respectively) when serving an MS in Iu mode.
   一个从Iu模式到A/Gb模式的inter-SGSN系统间改变发生在，当PMM-IDLE或者PMM-CONNCETED状态的MS从UTRAN或者GERAN Iu模式切换到了A/Gb模式，并且这个A/Gb模式的无线接入节点是由不同的SGSN提供服务的。在这个例子里，是RA的变化。因此，MS应发起一个A/Gb模式的RAU流程。这个RAU流程可以是联合的RA/LAU或仅RAU。这些RAU案例在图例54描述。在这个规范的上下文中，为MS服务于Iu模式的术语RNS或RNC可以参照GERAN BSS或者BSC进行类比。
A combined RA / LA update takes place in network operation mode I when the MS enters a new RA or when a GPRS-attached MS performs IMSI attach. The MS sends a Routeing Area Update Request indicating that an LA update may also need to be performed, in which case the SGSN forwards the LA update to the VLR. This concerns only idle mode (see TS 23.122 [7b]), as no combined RA / LA updates are performed during a CS connection.
NOTE: Direct Tunnel requires no additional functionality.
   一个联合的RA/LAU发生在网络操作模式I---并且当MS进入了一个新的RA或当一个GPRS附着的MS执行了IMSI附着.MS发送RAU Request消息指示这是一个LAU可能也需要执行,SGSN转发LAU给VLR.这仅和idle模式有关(参考TS23.122),因为在一个CS连接期间没有联合的RA/LAU被执行.
  注释：直接隧道要求无额外的功能处理。

Figure 54: Iu mode to A/Gb mode Inter-SGSN Change

1) The MS or RAN decides to perform an inter-system change, which makes the MS switch to a new cell where A/Gb mode has to be used, and stops transmission to the network.
   1）MS或RAN决定执行一个系统间改变，使得MS能切换到一个新的A/Gb模式下的小区，并且停止传递数据到网络。

2) The MS sends a Routeing Area Update Request (old RAI, old P TMSI Signature, Update Type, MS Network Capability, Voice domain preference and UE's usage setting) message to the new 2G SGSN. Update Type shall indicate RA update or combined RA / LA update, or, if the MS wants to perform an IMSI attach, combined RA / LA update with IMSI attach requested. The BSS shall add the Cell Global Identity including the RAC and LAC of the cell where the message was received before passing the message to the new 2G SGSN. The UE sets the voice domain preference and UE's usage setting according to its configuration, as described in clause 5.3.15.
   If there is an ongoing emergency bearer service and a Routing Area Update Request is received the Routing Area Update shall be rejected with a cause code indicating that access to GERAN is not allowed.
   2）MS发送RAU请求（old RAI、old P-TMSI签名、更新类型、MS网络能力、语音域优先级和UE的使用设置）消息给new 2G+3G SGSN。更新类型应指明这个一个RAU或是一个联合的RA/LAU或者，如果MS想执行一个IMSI的附着、带有IMSI附着请求的联合的RA/LAU。BSS应加入CGI（小区全球标识）并包括小区的RAC和LAC到这个接收的消息中，然后再传递给2G+3G SGSN。UE根据它自己的配置，按照章节5.3.15的描述，来设置语音域优先级和它的使用设置。

  如果有一个正在进行的紧急承载服务，并且在此种情况下执行了RAU，那网络侧应返回RAU reject，并带上原因值为"GERAN不允许".

3) The new 2G SGSN sends an SGSN Context Request (old RAI, TLLI, old P TMSI Signature, New SGSN Address) message to the old 3G SGSN to get the MM and PDP contexts for the MS. If the new SGSN provides functionality for Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the new SGSN may derive the old SGSN from the old RAI and the old P-TMSI (or TLLI) and send the SGSN Context Request message to this old SGSN. Otherwise, the new SGSN derives the old SGSN from the old RAI. In any case the new SGSN will derive an SGSN that it believes is the old SGSN. This derived SGSN is itself the old SGSN, or it is associated with the same pool area as the actual old SGSN and it will determine the correct old SGSN from the P-TMSI (or TLLI) and relay the message to that actual old SGSN. The old 3G-SGSN validates the old P TMSI Signature and responds with an appropriate error cause if it does not match the value stored in the old 3G SGSN. If the received old P-TMSI Signature does not match the stored value, the security functions in the new 2G-SGSN should be initiated. If the security functions authenticate the MS correctly, the new 2G-SGSN shall send an SGSN Context Request (old RAI, TLLI, MS Validated, New SGSN Address) message to the old 3G-SGSN. MS Validated indicates that the new 2G-SGSN has authenticated the MS. If the old P TMSI Signature was valid or if the new 2G-SGSN indicates that it has authenticated the MS correctly, the old 3G SGSN starts a timer. If the MS is not known in the old 3G SGSN, the old 3G SGSN responds with an appropriate error cause.
   3)new 2G SGSN发送一个SGSN Context Request(old RAI、TLLI、old P-TMSI签名、新SGSN地址）消息给old 3G SGSN来获取MS的MM和PDP上下文。如果new SGSN提供为多个CN节点提供到RAN节点的域内连接功能时，new SGSN可以根据old RAI以及old P-TMSI（或TLLI)来得到old SGSN的地址并发送SGSN Context Request消息给这个old SGSN。否则，new SGSN将从old RAI获取到old SGSN的地址。在任何的场景中，new SGSN都将获取一个SGSN并相信这就是old SGSN。而实际上，这个获取到的SGSN可能真的自己就是old SGSN，也可能只是关联到一个SGSN POOL区域的一个缺省SGSN，那这个获取到的SGSN将从P-TMSI（或TLLI)来得到正确的old SGSN并将消息传递给这个实际的old SGSN（但这个过程对new 2G SGSN来说是透明的）。old 3G-SGSN验证P-TMSI签名，如果签名和存储在它内部的签名值不匹配，那old 3G SGSN将响应一个合适的错误代码。如果收到的old P-TMSI签名和SGSN存储的签名不匹配，那将在new 2G-SGSN内触发一个安全功能（鉴权）的执行。如果安全功能能对MS正确鉴权，那new 2G-SGSN应发送一个SGSN Context Request（old RAI、TLLI、MS已验证、new SGSN地址）消息再给这个old 3G-SGSN。MS已验证代表new 2G-SGSN已经对MS做了鉴权。而如果old P-TMSI签名是正确的或者new 2G-SGSN指示已经对MS进行了正确的鉴权，old 3G SGSN将启动一个计时器。如果MS在old 3G SGSN内未知，那old 3G SGSN将响应一个合适的错误代码。
4) If the MS is PMM CONNECTED the old 3G SGSN sends an SRNS Context Request (IMSI) message to the SRNS. Upon receipt of this message the SRNS buffers and stops sending downlink PDUs to the MS and returns an SRNS Context Response (GTP SNDs, GTP SNUs, PDCP-SNDs, PDCP SNUs) message. The SRNS shall include for each PDP context the next in-sequence GTP sequence number to be sent to the MS and the GTP sequence number of the next uplink PDU to be tunnelled to the GGSN. For each active PDP context, which uses lossless PDCP, the SRNS also includes the uplink PDCP sequence number (PDCP SNU) downlink PDCP sequence number (PDCP-SND). PDCP SNU shall be the next in-sequence PDCP sequence number expected from the MS. PDCP-SND is the PDCP sequence number for the first downlink packet for which successful transmission has not been confirmed. The 3G SGSN shall strip off the eight most significant bits of the passed PDCP sequence numbers, thus converting them to SNDCP N PDU numbers and stores the N-PDU numbers in its PDP contexts.
   4)如果MS是PMM-CONNECTED状态的，那old 3G SGSN将发送SRNS Context Request（IMSI）消息给SRNS。一旦接收到这个消息，SRNS将缓存并且停止发送下行PDU给MS，并且返回一个SRNS Context Response(GTP SNDs、GTP SNUs、PDCP-SNDs、PDCP SNUs）消息。SRNS应对每个PDP上下文都包含下一个将要发送给MS的有序的GTP序列号，以及序列中下一个将要发送给GGSN被封装进隧道的上行 PDU。对每一个active的PDP上下文，如使用了无损PDCP，SRNS也应包含上行的PDCP序列号(PDCP SNU即Sequence Number Uplink)以及下行PDCP序列号(PDCP-SND即Sequence Number Downlink)。PDCP SNU是一个PDCP序列号，表示的是下一个期望的从MS接收的有序的上行数据报文。PDCP-SND是一个PDCP序列号，表示的是第一个成功传递但还没有被确认的下行数据包。3G SGSN应提取已经传递的PDCP序列号的八位最高有效位，将之转换为在2G GPRS PDP上下文中相应的SNDCP N PDU的值，并将N-PDU值存储到它的PDP上下文中。

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5) The old 3G SGSN responds with an SGSN Context Response (MM Context, PDP Contexts, Negotiated Evolved ARP) message. For each PDP context the old 3G SGSN shall include the GTP sequence number for the next uplink GTP PDU to be tunnelled to the GGSN and the next downlink GTP sequence number for the next in-sequence N PDU to be sent to the MS. Each PDP Context also includes the SNDCP Send N PDU Number (the value is 0) for the next in-sequence downlink N PDU to be sent in SNDCP acknowledged mode to the MS and the SNDCP Receive N PDU Number (= converted PDCP SNU) for the next in-sequence uplink N PDU to be received in SNDCP acknowledged mode from the MS. The new 3G-SGSN shall ignore the MS Network Capability contained in MM Context of SGSN Context Response only when it has previously received an MS Network Capability in the Routeing Area Request.
    5)old 3G-SGSN响应一个SGSN Context Response(MM上下文、PDP上下文、协商的演进ARP）消息。对每个PDP上下文，old 3G-SGSN都应包含了GTP序列号来指示在上行方向，将要通过隧道发给GGSN的GTP-PDU，以及用于指示下一个将要发送个MS的N-PDU的下行方向的GTP序列号。每个PDP上下文也包含了SNDCP发送N-PDU Number（值为0），用于下一个将要由确认模式送给MS的新型N-PDU，以及SNDCP接受N-PDU Number（对于转换的PDCP SNU)用于指示下一个将要从MS收到的SNDCP确认模式的上行N-PDU。new 3G-SGSN应忽略包含在SGSN Context Response消息的MM上下文中的MS网络侧能力---如果它在之前的RAU请求中从MS收到了网络侧能力的话。
6) Security functions may be executed. If the SGSN Context Response message did not include IMEISV and the ADD function is supported by the new 2G-SGSN, then the IMEISV shall be retrieved from the MS.
7) The new 2G SGSN sends an SGSN Context Acknowledge message to the old 3G SGSN. This informs the old 3G SGSN that the new 2G SGSN is ready to receive data packets belonging to the activated PDP contexts. The old SGSN marks in its context that the MSC/VLR association and the information in the GGSNs and the HLR are invalid. This triggers the MSC/VLR, the GGSNs, and the HLR to be updated if the MS initiates a RA update procedure back to the old SGSN before completing the ongoing RA update procedure.
   6）安全功能可以执行。如果SGSN Context Response消息不包含IMEISV并且在new 2G-SGSN中支持ADD功能，那应从MS获取IMEISV。
  7）new 2G-SGSN发送SGSN Context Acknowledge消息给old 3G-SGSN。这将通知old 3G-SGSN，new 2G-SGSN已经准备接收属于这个激活的PDP上下文的数据报文了。old SGSN将它的上下文和MSC/VLR的关联以及这个上下文和GGSN以及HLR的相关信息标记为invalid。这样，在完成正在进行的RAU流程之前，如果MS又返回到old SGSN并发起一个RAU流程，将触发和MSC/VLR、GGSN以及HLR的更新操作。
8) If the MS is in the PMM CONNECTED state, the old 3G SGSN sends an SRNS Data Forward Command (RAB ID, Transport Layer Address, Iu Transport Association) message to the SRNS. For each indicated RAB the SRNS starts duplicating and tunnelling the buffered GTP PDUs to the old 3G SGSN. For each radio bearer which uses lossless PDCP the SRNS shall start tunnelling the GTP-PDUs related to transmitted but not yet acknowledged PDCP PDUs to the old 3G SGSN together with their related downlink PDCP sequence numbers.Upon receipt of the SRNS Data Forward Command message from the 3G‑SGSN, the SRNS shall start the data-forwarding timer.
   8)如果MS是PMM-CONNECTED状态，old 3G-SGSN发送一个SRNS Data Forward Command（RAB ID、传输层地址、Iu传输关联）消息给SRNS。对于每个指示的RAB，SRNS开始将缓存的GTP-PDU进行复制并且通过隧道发送给old 3G-SGSN。对于每个使用了无损PDCP的无线承载，SRNS应开始将那些已经传递但还没有得到确认的PDCP PDU连同它们相关的下行PDCP序列号一起封装金GTP-PDU，通过隧道传递给old 3G-SGSN。一旦接收到从3G-SGSN来的SRNS Data Forward Command消息，SRNS应开始启动一个数据转发计时器。
9)  The old 3G SGSN tunnels the GTP PDUs to the new 2G SGSN. For GTPv1, the conversion of PDCP sequence numbers to SNDCP sequence numbers (the eight most significant bits shall be stripped off) shall be done in the new SGSN. No N-PDU sequence numbers shall be indicated for these N-PDUs.
10) The new 2G SGSN sends an Update PDP Context Request (new SGSN Address, TEID, QoS Negotiated, Negotiated Evolved ARP, serving network identity, CGI/SAI, User CSG Information, RAT type, MS Info Change Reporting support indication, NRSN) message to each GGSN concerned. The SGSN shall send the serving network identity to the GGSN. NRSN indicates SGSN support of the network requested bearer control. The inclusion of the Negotiated Evolved ARP IE indicates that the SGSN supports the Evolved ARP feature. If the new SGSN did not receive a Negotiated Evolved ARP IE in the SGSN Context Response message from the old SGSN then the new SGSN shall derive this value from the Allocation/Retention Priority of the QoS profile negotiated according to Annex E of TS 23.401 [89]. Each GGSN updates its PDP context fields and returns an Update PDP Context Response (TEID, Prohibit Payload Compression, APN Restriction, MS Info Change Reporting Action, CSG Information Reporting Action, BCM, Negotiated Evolved ARP) message. The GGSN sets the Negotiated Evolved ARP based on local policy or PCC. The Allocation/Retention Priority of the QoS Profile Negotiated is derived from the Evolved ARP according to the mapping principles of TS 23.401 [89], Annex E. The Prohibit Payload Compression indicates that the SGSN should negotiate no data compression for this PDP context. The SGSN shall apply the Negotiated Evolved ARP if received from the GGSN.
     9）old 3G-SGSN将GTP-PDU通过隧道发送给new 2G-SGSN。对于GTPV1，PDCP序列号到SNDCP序列号的转换（将八位最高有效位剥离）应在new SGSN中完成。没有N-PDU序列号来指示这些N-PDU。
  10）new 2G-SGSN发送update context request（新SGSN地址、TEID、协商的QOS、协商的演进ARP、服务网络ID、CGI/SAI，用户CSG信息，RAT类型，MS信息变化报告支持指示、NRSN）消息给每个关联的GGSN。SGSN应发送服务网络ID给GGSN。NRSN指示SGSN支持网络侧请求的承载控制。协商的演进ARP IE指示SGSN支持演进的ARP特性。如果new SGSN没有在从old SGSN来的SGSN Context Response消息中得到这个IE，那new SGSN应根据TS23.401的附录E的方法通过QOS profile里的分配/保持优先级来获取这个值。每个GGSN更新它的PDP上下文字段并返回一个update PDP context response（TEID，禁止payload压缩、APN限制、MS信息变化报告行动、CSG信息报告行动、BCM、协商的演进ARP)消息。GGSN根据本地策略或PCC设置协商的演进ARP。协商的QOS profile里的ARP是根据TS23.401的附录E的映射原则，从演进的ARP值中得到的。禁止payload压缩指示SGSN应为这个PDP上下文协商无数据压缩。SGSN如果从GGSN收到协商的演进ARP的话，则应应用这个值。
11)  The new 2G SGSN informs the HLR of the change of SGSN by sending an Update GPRS Location (SGSN Number, SGSN Address, IMSI, IMEISV, Homogenous Support of IMS Over PS Sessions) message to the HLR. IMEISV is sent if the ADD function is supported. Homogenous Support of IMS Over PS Sessions indicates whether or not "IMS Voice over PS Sessions" is supported homogeneously in all RAs in the serving SGSN.
12)  The HLR sends a Cancel Location (IMSI) message to the old 3G SGSN. The old 3G SGSN acknowledges with a Cancel Location Ack (IMSI) message. The old 3G SGSN removes the MM and PDP contexts if the timer described in step 3 is not running. If the timer is running, the MM and PDP contexts shall be removed when the timer expires.
13)  When the MS is PMM CONNECTED, the old 3G SGSN sends an Iu Release Command message to the SRNS. When the RNC data-forwarding timer has expired, the SRNS responds with an Iu Release Complete message.
   11）new 2G-SGSN通知HLR关于SGSN的变化，通过发送update GPRS location（SGSN number、SGSN地址、IMSI、IMEISV、IMS over PS会话的同质支持）给HLR来通知它。如果支持ADD功能则发送IMEISV。IMS over PS会话的同质支持指示"IMS voice over PS会话”的能力在服务SGSN的所有RA中都能被等价的支持（即采取相同的策略）。
  12）HLR发送cancel location（IMSI）消息给old 3G-SGSN。old 3G-SGSN发送cancel location（IMSI)ack消息进行确认。old 3G-SGSN发现，如果在步骤3描述的计时器没有运行的话，那它将移除MM和PDP上下文。如果这个计时器运行了，那MM和PDP上下文将在计时器超时后被移除。
  13）当MS是在PMM-CONNECTED状态，old 3G-SGSN发送一个Iu Release Command消息给SRNS。当RNC数据转发计时器超时，SRNS响应一个Iu Release Compete消息。
14) The HLR sends an Insert Subscriber Data (IMSI, Subscription Data) message to the new 2G SGSN. The 2G SGSN constructs an MM context and PDP contexts for the MS and returns an Insert Subscriber Data Ack (IMSI) message to the HLR. If the S6d interface is used between S4-SGSN and HSS the messages "Insert Subscriber Data" and "Insert Subscriber Data Ack" are not used. Instead the Subscription Data is sent by HSS in the message Update Location Ack (Step 15).
15) The HLR acknowledges the Update GPRS Location by returning an Update GPRS Location Ack (IMSI, GPRS Subscriber Data (only if S6d interface is used)) message to the new 2G SGSN.
   14）HLR发送一个Insert Subscriber Data(IMSI、签约数据）消息给new 2G-SGSN。2G-SGSN为MS构建一个MM和PDP上下文并且返回一个Insert Subscriber Data ACK（IMSI）消息给HLR。如果在S4-SGSN和HSS之间使用的是S6d接口，则消息"Insert Subscriber Data"和"Insert Subscriber Data ACK"将不再使用。作为替代，这个签约数据将在由HSS发过来的"update location ack"消息中携带。（步骤15）
  15）HLR确认GPRS的位置更新，并返回一个update GPRS location ACK（IMSI、GPRS签约数据(仅当S6d接口时才使用)）消息给new 2G-SGSN。

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16) If the association has to be established i.e. if Update Type indicates combined RA / LA update with IMSI attach requested, or if the LA changed with the routeing area update, the new 2G SGSN sends a Location Update Request (new LAI, IMSI, SGSN Number, Location Update Type) to the VLR. Location Update Type shall indicate IMSI attach if Update Type in step 1 indicated combined RA / LA update with IMSI attach requested. Otherwise, Location Update Type shall indicate normal location update. When the SGSN does not provide functionality for the Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the VLR number is derived from the RAI. When the SGSN provides functionality for Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the SGSN uses the RAI and a hash value from the IMSI to determine the VLR number. The 2G SGSN starts the location update procedure towards the new MSC/VLR upon receipt of the first Insert Subscriber Data message from the HLR in step 14). The VLR creates or updates the association with the 2G SGSN by storing SGSN Number.
   16)如果关联需要建立，也就是更新类型指示了带有IMSI附着的联合的RA/LAU请求，或在RAU时发生了LA的变化，那么new 2G SGSN发送Location Update Request(新LAI、IMSI、SGSN编号、Location Update Type)给VLR。Location Update Type应指示为IMSI附着---如果在步骤1的更新类型指示的是带有IMSI附着请求的联合RA/LAU。除此以外，Location Update Type应指示为一个正常的Location Update。当SGSN不为多个CN节点提供到RAN节点的域内连接功能的话，VLR编号将从RAI获取。当SGSN提供这个功能时，SGSN使用RAI以及从IMSI得到的一个哈希函数来决定VLR编号。2G SGSN一旦在步骤14接收到从HLR来的Insert Subscriber Data消息，将开始到new MSC/VLR的位置更新流程。VLR通过存储SGSN编号来创建或更新与2G+3G SGSN的关联。
17) If the subscriber data in the VLR is marked as not confirmed by the HLR, the new VLR informs the HLR. The HLR cancels the old VLR and inserts subscriber data in the new VLR:
a)  The new VLR sends an Update Location (new VLR) to the HLR.
b)  The HLR cancels the data in the old VLR by sending Cancel Location (IMSI) to the old VLR.
c)  The old VLR acknowledges with Cancel Location Ack (IMSI).
d)  The HLR sends Insert Subscriber Data (IMSI, subscriber data) to the new VLR.
e)  The new VLR acknowledges with Insert Subscriber Data Ack (IMSI).
f)  The HLR responds with Update Location Ack (IMSI) to the new VLR.
   17)如果VLR上的签约数据标记为未得到HLR的确认，则new VLR要通知HLR。HLR取消在old VLR上的数据并在new VLR插入新的用户签约数据：
a）new VLR发送update location(new VLR)给HLR。
b) HLR发送cancel location(IMSI)消息给old VLR来取消其上的数据。
c）old VLR发送cancel location ack（IMSI)进行确认。
d）HLR发送插入签约用户数据(IMSI,签约数据）给new VLR。
e）new VLR发送insert subscriber data ack(IMSI)进行确认。
f）HLR发送update location ack（IMSI）给new VLR进行响应。
18) The new VLR allocates a new TMSI and responds with Location Update Accept (VLR TMSI) to the 2G SGSN. VLR TMSI is optional if the VLR has not changed.
19) The new 2G SGSN validates the MS's presence in the new RA. If due to roaming restrictions or access restrictions the MS is not allowed to be attached in the RA, or if subscription checking fails, the new 2G SGSN rejects the routeing area update with an appropriate cause. If all checks are successful, the new 2G SGSN constructs MM and PDP contexts for the MS. A logical link is established between the new 2G SGSN and the MS. 2G-SGSN initiates the establishment procedure. The new 2G SGSN responds to the MS with a Routeing Area Update Accept (P TMSI, P TMSI Signature, Receive N PDU Number (= converted PDCP SNU), IMS voice over PS Session Supported Indication) message. Receive N PDU Number contains the acknowledgements for each NSAPI which used lossless PDCP before the start of the update procedure, thereby confirming all mobile-originated N PDUs successfully transferred before the start of the update procedure. If Receive N PDU Number confirms the reception of N PDUs, the MS shall discard these N PDUs. The IMS voice over PS Session Supported Indication is set as described in clause 5.3.8.
  18）new VLR分配一个新的VLR TMSI并且响应location update accept(VLR TMSI)给2G SGSN。VLR TMSI是可选的，如果VLR没有发生变化的话。
  19）2G SGSN验证在新RA中MS的存在性。如果因为漫游限制或接入限制，MS不允许附着到RA，或者如果签约检查失败，则2G+3G SGSN拒绝RAU并给出原因值。如果所有检查都成功，new 2G SGSN构建MS的MM和PDP上下文。一条逻辑链路将在new 2G SGSN和MS之间建立。2G SGSN发起建立流程。new 2G SGSN将发送一个RAU accept(P-TMSI、P-TMSI签名、Receive N-PDU Number（=转换的PDCP SNU)，IMS voice over PS会话指示指示）消息给MS。Receive N-PDU Number包含了在更新流程开始之前，使用了无损PDCP的对每个NSAPI的确认，因此确认了在开始更新流程之前所有MS发起的成功传递的N-PDU。如果Receive N-PDU Number确认了对N-PDU的接收，那些N-PDU应被MS丢弃。IMS voice over PS会话指示指示根据5.3.8章节描述设置。
20) The MS acknowledges the new P TMSI by returning a Routeing Area Update Complete (Receive N PDU Number (= converted PDCP SND)) message to the SGSN. Receive N PDU Number contains the acknowledgements for each lossless PDCP used by the MS before the start of the update procedure, thereby confirming all mobile-terminated N PDUs successfully transferred before the start of the update procedure. If Receive N PDU Number confirms the reception of N PDUs that were forwarded from the old 3G-SGSN, the new 2G-SGSN shall discard these N PDUs. The MS deducts Receive N PDU number from PDCP SND by stripping off the eight most significant bits. PDCP SND is the PDCP sequence number for the next expected in-sequence downlink packet to be received in the MS per radio bearer, which used lossless PDCP. The new 2G-SGSN negotiates with the MS for each NSAPI the use of acknowledged or unacknowledged SNDCP regardless whether the SRNS used lossless PDCP or not.
   20)MS返回RAU Complete(Receive N-PDU Number）消息给SGSN来确认对新P-TMSI的分配。Receive N-PDU Number（=转换的PDCP SND）包含了更新流程开始之前，使用了无损PDCP的确认，因此确认了在开始更新流程之前所有MS接收的成功传递的N-PDU。如果Receive N-PDU Number确认了从old 3G-SGSN转发过来的N-PDU的接收，那么N-PDU应被new 2G SGSN丢弃。MS通过剥离PDCP SND的高8位有效位来得到Receive N-PDU Number。PDCP SND是一个PDCP序列号，用于标识在每个无线承载上，下一个期望在MS上收到的使用了无损PDCP的下行数据报文。New 2G-SGSN和MS为每个NSAPI协商使用确认或非确认SNDCP，而不管之前SRNS是否使用PDCP或没有使用。
21) The new 2G SGSN sends TMSI Reallocation Complete message to the new VLR if the MS confirms the VLR TMSI.
22) The 2G SGSN and the BSS may execute the BSS Packet Flow Context procedure.
If the new SGSN is unable to update the PDP context in one or more GGSN(s), the new SGSN shall deactivate the corresponding PDP contexts as described in clause "SGSN-initiated PDP Context Deactivation Procedure". This shall not cause the SGSN to reject the routeing area update.
The PDP Contexts shall be sent from old to new SGSN in a prioritized order, i.e. the most important PDP Context first in the SGSN Context Response message. (The prioritization method is implementation dependent, but should be based on the current activity).
   21）new 2G SGSN发送TMSI Reallocation Complete消息给new VLR---如果MS确认了对VLR TMSI的分配。
  22）2G SGSN和BSS可以执行BSS Packet Flow Context流程。
   如果new SGSN不能同一个或多个GGSN更新PDP上下文、new SGSN应将相应的PDP上下文去激活。但这不应该导致SGSN拒绝RAU。
   PDP上下文应按照一定优先级顺序从old发向new SGSN，也就是最重要的PDP上下文第一个出现在SGSN Context Response消息中。（优先级的方法取决于具体的实现，但应基于当前的一些活跃事件来决定）。
The new SGSN shall determine the Maximum APN restriction based on the received APN Restriction of each PDP context from the GGSN and then store the new Maximum APN restriction value.
If the new SGSN is unable to support the same number of active PDP contexts as received from old SGSN, the new SGSN should use the prioritisation sent by old SGSN as input when deciding which PDP contexts to maintain active and which ones to delete. In any case, the new SGSN shall first update all contexts in one or more GGSNs and then deactivate the context(s) that it cannot maintain as described in clause "SGSN-initiated PDP Context Deactivation Procedure". This shall not cause the SGSN to reject the routeing area update.
   New SGSN应根据从GGSN接收到的每个PDP上下文的APN限制，来决定最大的APN限制，并且存储这个新的最大APN限制的值。
  如果new SGSN不能支持从old SGSN接收到的相同数量的active PDP上下文,new SGSN应使用old SGSN发过来的优先级排序做为参考，以此来决定哪些PDP上下文应保持哪些则应删除。在任意场景，new SGSN应首先更新一个或多个GGSN中的所有上下文，并且将不能保持的上下文去激活。但这不应该导致SGSN拒绝RAU。

爱卫生

   In this case, clause 6.13.2.1.1 applies except for steps 3, 5, 7, 9 and 10, as well as clause-specific general statements stated below.
  在本例中的流程，除了图例54-2的步骤3，5，7，9，10外，其他都适用于6.13.2.1.1中的流程。
  

Figure 54-2: steps 3, 5, 7, 9 for Iu mode to A/Gb mode Inter-SGSN Change using S4

    Steps 3, 5 and 7 are identical to the Gn/Gp case in clause 6.13.2.2.1, except that:
- Message SGSN Context Request is replaced by message Context Request;
- Parameter PDP Contexts is replaced by parameter EPS Bearer Contexts.
MM Context and EPS Bearer Context when used at the S16 interface are defined by clause 13.2.2. For RAU between two S4-SGSNs, the old SGSN shall include the APN Restriction, CGI/SAI/RAI change support indication and Change Reporting Action in the Context Response message.

    步骤3，5，7和6.13.2.2.1中的基于Gn/Gp的例子是相同的，区别在于：

-- 消息SGSN Context Request被Context Request消息替代；

-- 参数PDP Context被参数EPS Bearer Context替代。

  在使用S16接口时的MM上下文和EPS承载上下文在13.2.2章定义。对于两个S4-SGSN之间的RAU，old SGSN应在Context Response消息中包含APN Restriction,CGI/SAI/RAI变更支持指示和变更报告指示。

9) In case Direct Tunnel in Iu mode was not established, the old 3G SGSN tunnels the GTP PDUs to the new 2G SGSN. For GTPv2 or GTPv1 user plane, the conversion of PDCP sequence numbers to SNDCP sequence numbers (the eight most significant bits shall be stripped off) shall be done in the new SGSN. No N PDU sequence numbers shall be indicated for these N PDUs.
In case Direct Tunnel in Iu mode was established, the packets are forwarded via the S GW.
  9）如果在Iu模式的直接隧道没有建立，则old 3G SGSN将GTP PDU通过隧道发给new 2G SGSN。对于GTPV2或GTPV1的用户平面，new SGSN应将PDCP序列号转换为SNDCP序列号（剥离最高八位有效位）。没有N-PDU序列号来指示这些N-PDU。

  一旦在Iu模式建立了直接隧道，这些包将转发给SGW。

10）Box（B）

Figure 54-3: step 10 for Iu mode to A/Gb mode Inter-SGSN Change using S4

NOTE: Steps a) and d) are common for architecture variants with GTP-based S5/S8 and PMIP-based S5/S8. For a PMIP-based S5/S8, procedure step (A1) is defined in TS 23.402 [90]. Steps b) and c) in Figure 54-3 concern GTP-based S5/S8.
  注释：步骤a和d对于使用GTP或PMIP的S5/S8来说都是公共的。对于基于PMIP的S5/S8，步骤A1在TS23.402定义。步骤b和c和基于GTP的S5/S8接口有关。

a) The new 2G SGSN sends a Modify Bearer Request (new SGSN Address, TEID, serving network identity, CGI/SAI, User CSG Information, RAT type, MS Info Change Reporting support indication) message to the Serving GW. The SGSN shall send the serving network identity to the Serving GW.
b) The Serving GW informs the P GW(s) about the change of Serving GW Address and TEID, as well as about RAT type that e.g. can be used for charging, by sending the message Modify Bearer Request (Serving GW Address and TEID, RAT type) to the concerned P GW(s). If dynamic PCC is deployed, and RAT type information needs to be conveyed from the P GW to the PCRF, then the P GW shall send RAT type information to the PCRF as defined in TS 23.203 [88].
  a)new 2G SGSN发送Modify Bearer Request(new SGSN地址、TEID、服务网络ID、CGI/SAI、用户CSG信息、RAT类型、MS信息变化报告支持指示）消息给SGW。SGSN应发送服务网络ID给SGW。

  b）SGW通过发送Modify Bearer Request消息来通知PGW关于SGW地址和TEID的变化，以及RAT类型（例如可用于计费目的）。如果部署了动态PCC，则RAT类型信息将需要由PGW传递给PCRF，然后PGW应将RAT类型信息发送给在规范TS23.203中定义的PCRF。

c) Each P GW updates its context fields and returns a Modify Bearer Response (MSISDN, P GW address and TEID, Prohibit Payload Compression, MS Info Change Reporting Action, CSG Information Reporting Action) message. The Prohibit Payload Compression indicates that the SGSN should negotiate no data compression for this EPS Bearer context. MSISDN is included if available in the stored UE context.
d) The Serving GW updates the Address for User Plane and TEID for downlink data and return a Modify Bearer Response (Serving GW address and TEID, P GW address and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN GW(s) for uplink traffic, CSG Information Reporting Action) message.
  c)每个PGW更新它的上下文字段并返回Modify Bearer Response (MSISDN、PGW地址和TEID、禁止payload压缩、MS信息变化报告行动、CSG信息报告行动）消息。禁止payload压缩指示SGSN不应为这个EPS承载上下文来协商数据压缩。MSISDN如果在存储的UE上下文中有的话也应提供。

  d) SGW更新下行数据的用户平面地址和TEID并返回一个Modify Bearer Response (SGW地址和TEID、PGW上用于上行流量的PGW地址和TEID（基于GTP的S5/S8）或GRE密钥（基于PMIP的S5/S8)，CSG信息报告行动）消息。

If the new SGSN is unable to update the Bearer context in the S GW or in one or more P GW(s), the new SGSN shall deactivate the corresponding Bearer contexts as described in clause "SGSN initiated PDP Context Deactivation Procedure". This shall not cause the SGSN to reject the routeing area update.
The Bearer Contexts shall be sent from old to new SGSN in a prioritized order, i.e. the most important Bearer Context first in the Context Response message. (The prioritization method is implementation dependent, but should be based on the current activity).
The new SGSN shall determine the Maximum APN restriction based on the received APN Restriction of each Bearer context from the P GW(s) or old S4-SGSN and then store the new Maximum APN restriction value.
The bearer contexts shall be prioritized by the new SGSN. If the new SGSN is unable to support the same number of active Bearer contexts as received from old SGSN, the new SGSN should use the prioritisation when deciding which Bearer contexts to maintain active and which ones to delete. In any case, the new SGSN shall first update all contexts in the S GW and in one or more P GW(s) and then deactivate the context(s) that it cannot maintain as described in clause "SGSN initiated PDP Context Deactivation Procedure". This shall not cause the SGSN to reject the routeing area update.
     如果new SGSN不能更新在SGW或一个或多个PGW中的承载上下文，那new SGSN应将相应的承载上下文去激活，如章节“initiated PDP Context Deactivation Procedure”描述的那样。这不应导致SGSN拒绝RAU。

   Bearer Contexts应按照优先级顺序从old传送到new SGSN，也就是最重要的Bearer Context优先出现在Context Response消息中。（优先级的方法取决于具体的实现，但应基于当前的事件给出。）

  New SGSN应根据从PGW或old S4-SGSN接收到的每个承载上下文的APN限制，来决定最大的APN限制，并且存储这个新的最大APN限制的值。

   Bearer Contexts应在new SGSN中按照优先级顺序排序。如果new SGSN不能支持从old SGSN来的相同数量的active承载上下文，那new SGSN应根据优先级来决定哪些承载上下文应该保持或被删除。在任何场景下，new SGSN应首先在SGW和一个或多个PGW中更新所有的上下文，然后将不能保持的上下文按照章节“SGSN initiated PDP Context Deactivation Procedure”的描述来去激活。这不应导致SGSN拒绝RAU。

爱卫生

6.13.2.2.1 A/Gb mode to Iu mode Inter-SGSN Change using Gn/Gp
The inter-system change from A/Gb mode to Iu mode takes place when a GPRS-attached MS changes from A/Gb mode to UTRAN or GERAN Iu mode and the new RAN node serving the MS is served by a different SGSN. In this case the RA changes. Therefore, the MS shall initiate a Iu mode RA update procedure by establishing an RRC connection and initiating the RA update procedure. The RA update procedure is either combined RA / LA update or only RA update, these RA update cases are illustrated in Figure 55. In the context of this specification, the terms RNS or RNC refer also to a GERAN BSS or BSC (respectively) when serving an MS in Iu mode.
If the network operates in mode I, then an MS, that is both PS-attached and CS-attached, shall perform the Combined RA / LA Update procedures. This concerns only idle mode (see TS 23.122 [7b]), as no combined RA / LA updates are performed during a CS connection.
   从A/Gb模式到Iu模式的inter-system change发生在当一个已经GPRS附着的MS从A/Gb模式切换到UTRAN或GERAN Iu模式并且新的为MS提供服务的RAN是由不同的SGSN管理的时候。在这个例子里发生了RA的变化。因此，MS应建立一个RRC连接以及发起一个Iu模式RAU流程，并发起一个RAU流程。RAU流程或者是联合的RA/LAU或仅是RAU，这些RAU例子在图例55描述。在本规范的上下文中，在Iu模式为MS服务的术语RNS或RNC可相应参考对照GERAN BSS或BSC。
   如果网络模式为mode I，那么一个MS，如果PS和CS都附着了，应执行联合的RA/LAU流程。这仅和idle模式有关（参考TS23.122，因为在一个CS连接期间没有联合的RA/LAU执行）。

Figure 55: A/Gb mode to Iu mode Inter SGSN Change

1) The MS or RAN decides to perform an inter-system change, which makes the MS switch to a new cell where Iu mode has to be used, and stops transmission to the network.
  1)MS或RAN决定执行inter-system change，使得MS切换到一个新小区并使用Iu模式，并停止到网络侧的数据传输。

2) The MS sends a Routeing Area Update Request (P TMSI, old RAI, old P TMSI Signature, Update Type, CM, MS Network Capability, Voice domain preference and UE's usage setting) message to the new 3G SGSN. Update Type shall indicate RA update or combined RA / LA update, or, if the MS wants to perform an IMSI attach, combined RA / LA update with IMSI attach requested, and also if the MS has a follow-on request, i.e. if there is pending uplink traffic (signalling or data). The SGSN may use, as an implementation option, the follow-on request indication to release or keep the Iu connection after the completion of the RA update procedure. The SRNC shall add the Routeing Area Identity before forwarding the message to the 3G SGSN. This RA identity corresponds to the RAI in the MM system information sent by the SRNC to the MS. The UE sets the voice domain preference and UE's usage setting according to its configuration, as described in clause 5.3.15.
  2)MS发送RAU请求（P-TMSI、old RAI、old P-TMSI签名、更新类型、CM、MS网络侧能力、语音域优先级以及UE的使用设置）消息给new 3G SGSN。更新类型指明这是个一个RAU或是一个联合的RA/LAU或者，如果MS想执行一个IMSI的附着、带有IMSI附着请求的联合的RA/LAU，并且如果MS有一个后续的请求，也就是如果它有处于pending状态的上行流量（信令或数据）。SGSN可以使用，作为一个实现的可选项，使用follow-on request指示来决定在RAU流程完成之后是否释放或保持Iu连接。SRNC应加入RAI然后再传递给3G SGSN。RA标识对应到从SRNC发送给MS的MM系统新中的RAI。UE根据它自己的配置，按照章节5.3.15的描述，来设置语音域优先级和它的使用设置。

  3) The new 3G SGSN uses the old RAI received from the MS to derive the old 2G SGSN address, and sends an SGSN Context Request (old RAI, old P TMSI, New SGSN Address) message to the old 2G SGSN to get the MM and PDP contexts for the MS. If the new SGSN provides functionality for Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the new SGSN may derive the old SGSN from the old RAI and the old P-TMSI and send the SGSN Context Request message to this old SGSN. Otherwise, the new SGSN derives the old SGSN from the old RAI. In any case the new SGSN will derive an SGSN that it believes is the old SGSN. This derived SGSN is itself the old SGSN, or it is associated with the same pool area as the actual old SGSN and it will determine the correct old SGSN from the P-TMSI and relay the message to that actual old SGSN. The old 2G-SGSN validates the old P TMSI Signature and responds with an appropriate error cause if it does not match the value stored in the old 2G SGSN. If the received old P-TMSI Signature does not match the stored value, the old 2G-SGSN should initiate the security functions in the new 3G-SGSN. If the security functions authenticate the MS correctly, the new 3G-SGSN shall send an SGSN Context Request (old RAI, IMSI, MS Validated, New SGSN Address) message to the old 2G-SGSN. MS Validated indicates that the new 3G-SGSN has authenticated the MS. If the old P TMSI Signature was valid or if the new 3G-SGSN indicates that it has authenticated the MS correctly, the old 2G SGSN starts a timer and stops the transmission of N PDUs to the MS.
   3)new 3G SGSN使用从MS收到的old RAI来得到old 2G SGSN地址，发送一个SGSN Context Request(old RAI、old P-TMSI、新SGSN地址）消息给old 2G SGSN来获取MS的MM和PDP上下文。如果new SGSN提供为多个CN节点提供到RAN节点的域内连接功能时，new SGSN可以根据old RAI以及old P-TMSI来得到old SGSN的地址并发送SGSN Context Request消息给这个old SGSN。否则，new SGSN将从old RAI获取到old SGSN的地址。在任何的场景中，new SGSN都将获取一个SGSN并相信这就是old SGSN。而实际上，这个获取到的SGSN可能真的自己就是old SGSN，也可能只是关联到一个SGSN POOL区域的一个缺省SGSN，那这个获取到的SGSN将从P-TMSI来得到正确的old SGSN并将消息传递给这个实际的old SGSN。old 2G-SGSN验证old P-TMSI签名，如果签名和存储在它内部的签名值不匹配，那old 2G SGSN将响应一个合适的错误代码。如果收到的old P-TMSI签名和SGSN存储的签名不匹配，那将在new 3G-SGSN内触发一个安全功能（鉴权）的执行。如果安全功能能对MS正确鉴权，那new 3G-SGSN应发送一个SGSN Context Request（old RAI、IMSI、MS已验证、new SGSN地址）消息再给这个old 2G-SGSN。MS已验证代表new 3G-SGSN已经对MS做了鉴权。而如果old P-TMSI签名是正确的或者new 3G-SGSN指示已经对MS进行了正确的鉴权，old 2G SGSN将启动一个计时器并且停止传送N-PDU给MS。

4) The old 2G SGSN responds with an SGSN Context Response (MM Context, PDP Contexts, Negotiated Evolved ARP) message. Each PDP Context includes the GTP sequence number for the next downlink N PDU to be sent to the MS and the GTP sequence number for the next uplink N PDU to be tunnelled to the GGSN. Each PDP Context also includes the SNDCP Send N PDU Number for the next downlink N PDU to be sent in acknowledged mode SNDCP to the MS and the SNDCP Receive N PDU Number for the next uplink N PDU to be received in acknowledged mode SNDCP from the MS. The new 3G-SGSN derives the corresponding PDCP sequence numbers from these N PDU sequence numbers by adding eight most significant bits "1". These PDCP sequence numbers are stored in the 3G-SGSN PDP contexts. The new 3G-SGSN shall ignore the MS Network Capability contained in MM Context of SGSN Context Response only when it has previously received an MS Network Capability in the Routeing Area Request.
   4)old 2G SGSN响应一个SGSN Context Response（MM上下文、PDP上下文、协商的演进ARP)消息。每个PDP上下文包括了下一个要发给MS的下行N-PDU的序列号以及下一个将被封进隧道送给GGSN的上行N-PDU的GTP序列号。每个PDP上下文也包含了下一个下行方向要通过确认模式SNDCP发送给MS的N-PDU的SNDCP Send N-PDU Number，以及下一个上行方向通过确认模式SNDCP从MS接收的上行N-PDU的SNDCP Receive N-PDU Number。New 3G-SGSN从这些N-PDU序列号中加上8个有效比特位1得到对应的PDCP序列号。这些PDCP序列号将存储在3G-SGSN PDP上下文中。New 3G-SGSN只有在之前从RA请求中收到了MS网络侧能力的时候，才可以忽略在SGSN Context Response消息中的MM Context里包含的MS网络侧能力。

5) Security functions may be executed. If the SGSN Context Response message did not include IMEISV and the ADD function is supported by the new 3G-SGSN, then the IMEISV shall be retrieved from the MS.
6) The new 3G SGSN sends an SGSN Context Acknowledge message to the old 2G SGSN. This informs the old 2G SGSN that the new 3G SGSN is ready to receive data packets belonging to the activated PDP contexts. The old SGSN marks in its context that the MSC/VLR association and the information in the GGSNs and the HLR are invalid. This triggers the MSC/VLR, the GGSNs, and the HLR to be updated if the MS initiates a routeing area update procedure back to the old SGSN before completing the ongoing routeing area update procedure.
  5)安全功能可以执行。如果SGSN Context Response消息不包含IMEISV并且在new 3G-SGSN中支持ADD功能，那应从MS获取IMEISV。
   6)New 3G-SGSN发送SGSN Context Acknowledge消息给old 2G-SGSN。这将通知old 2G-SGSN，new 3G-SGSN已经准备接收属于这个激活的PDP上下文的数据报文了。Old SGSN将它的上下文和MSC/VLR的关联以及这个上下文和GGSN以及HLR的相关信息标记为invalid。这样，在完成正在进行的RAU流程之前，如果MS又返回到old SGSN并发起一个RAU流程，将触发和MSC/VLR、GGSN以及HLR的更新操作。

7) The old 2G SGSN duplicates the buffered N PDUs and starts tunnelling them to the new 3G SGSN. Additional N PDUs received from the GGSN before the timer described in step 3 expires are also duplicated and tunnelled to the new 3G SGSN. N-PDUs that were already sent to the MS in acknowledged mode SNDCP and that are not yet acknowledged by the MS are tunnelled together with their related SNDCP N-PDU sequence number. No PDCP sequence numbers shall be indicated for these N-PDUs. No N PDUs shall be forwarded to the new 3G SGSN after expiry of the timer described in step 3.
  7)Old 2G SGSN将缓存中的N-PDU复制并且开始通过隧道传递给new 3G SGSN。在步骤3的计时器超时之前从GGSN收到了额外的N-PDU，则也复制并通过隧道发送给new 3G-SGSN。那些由确认模式SNDCP已经发给MS的N-PDU但如果没有得到MS的确认的话，则将和他们相关的SNDCP N-DPU序列号一起隧道发送。没有PDCP序列号来指示这些N-PDU。在步骤3的计时器超时之后，将不再转发N-PDU给new 3G-SGSN。

8) The new 3G SGSN sends an Update PDP Context Request (new SGSN Address, TEID, QoS Negotiated, Negotiated Evolved ARP, serving network identity, CGI/SAI, User CSG Information, RAT type, MS Info Change Reporting support indication, NRSN) message to each GGSN concerned. The SGSN shall send the serving network identity to the GGSN. NRSN indicates SGSN support of the network requested bearer control. The inclusion of the Negotiated Evolved ARP IE indicates that the SGSN supports the Evolved ARP feature. If the new SGSN did not receive a Negotiated Evolved ARP IE in the SGSN Context Response message from the old SGSN then the new SGSN shall derive this value from the Allocation/Retention Priority of the QoS profile negotiated according to Annex E of TS 23.401 [89]. Each GGSN updates its PDP context fields and returns an Update PDP Context Response (TEID, Prohibit Payload Compression, APN Restriction, MS Info Change Reporting Action, CSG Information Reporting Action, BCM, Negotiated Evolved ARP) message. The GGSN sets the Negotiated Evolved ARP based on local policy or PCC. The Allocation/Retention Priority of the QoS Profile Negotiated is derived from the Evolved ARP according to the mapping principles of TS 23.401 [89], Annex E. The Prohibit Payload Compression indicates that the SGSN should negotiate no data compression for this PDP context. The SGSN shall apply the Negotiated Evolved ARP if received from the GGSN.
  8）new 3G-SGSN发送update context request（新SGSN地址、TEID、协商的QOS、协商的演进ARP、服务网络ID、CGI/SAI，用户CSG信息，RAT类型，MS信息变化报告支持指示、NRSN）消息给每个关联的GGSN。SGSN应发送服务网络ID给GGSN。NRSN指示SGSN支持网络侧请求的承载控制。协商的演进ARP IE指示SGSN支持演进的ARP特性。如果new SGSN没有在从old SGSN来的SGSN Context Response消息中得到这个IE，那new SGSN应根据TS23.401的附录E的方法通过QOS profile里的分配/保持优先级来获取这个值。每个GGSN更新它的PDP上下文字段并返回一个update PDP context response（TEID，禁止payload压缩、APN限制、MS信息变化报告行动、CSG信息报告行动、BCM、协商的演进ARP)消息。GGSN根据本地策略或PCC设置协商的演进ARP。协商的QOS profile里的ARP是根据TS23.401的附录E的映射原则，从演进的ARP值中得到的。禁止payload压缩指示SGSN应为这个PDP上下文协商无数据压缩。SGSN如果从GGSN收到协商的演进ARP的话，则应应用这个值。
9) The new 3G SGSN informs the HLR of the change of SGSN by sending an Update GPRS Location (SGSN Number, SGSN Address, IMSI, IMEISV, Homogenous Support of IMS Over PS Sessions) message to the HLR. IMEISV is sent if the ADD function is supported. Homogenous Support of IMS Over PS Sessions indicates whether or not "IMS Voice over PS Sessions" is supported homogeneously in all RAs in the serving SGSN.
10) The HLR sends a Cancel Location (IMSI, Cancellation Type) message to the old 2G SGSN. The old 2G SGSN removes the MM and PDP contexts if the timer described in step 3 is not running. If the timer is running, the MM and PDP contexts are removed when the timer expires. The old 2G SGSN acknowledges with a Cancel Location Ack (IMSI) message.
11) The HLR sends an Insert Subscriber Data (IMSI, Subscription Data) message to the new 3G SGSN. The 3G SGSN constructs an MM context for the MS and returns an Insert Subscriber Data Ack (IMSI) message to the HLR. If the S6d interface is used between S4-SGSN and HSS the messages "Insert Subscriber Data" and "Insert Subscriber Data Ack" are not used. Instead the Subscription Data is sent by HSS in the message Update Location Ack (Step 15).
  9）new 3G-SGSN通知HLR关于SGSN的变化，通过发送update GPRS location（SGSN number、SGSN地址、IMSI、IMEISV、IMS over PS会话的同质支持）给HLR来通知它。如果支持ADD功能则发送IMEISV。IMS over PS会话的同质支持指示"IMS voice over PS会话”的能力在服务SGSN的所有RA中都能被等价的支持（即采取相同的策略）。
  10）HLR发送cancel location（IMSI、取消类型）消息给old 2G-SGSN。Old 2G-SGSN发现，如果在步骤3描述的计时器没有运行的话，那它将移除MM和PDP上下文。如果这个计时器运行了，那MM和PDP上下文将在计时器超时后被移除。Old 2G SGSN发送Cancel Location Ack(IMSI)消息进行确认。
  11）HLR发送一个Insert Subscriber Data(IMSI、签约数据）消息给new 3G-SGSN。3G-SGSN为MS构建一个MM和PDP上下文并且返回一个Insert Subscriber Data ACK（IMSI）消息给HLR。如果在S4-SGSN和HSS之间使用的是S6d接口，则消息"Insert Subscriber Data"和"Insert Subscriber Data ACK"将不再使用。作为替代，这个签约数据将在由HSS发过来的"update location ack"消息中携带。（步骤15）

12) The HLR acknowledges the Update GPRS Location by returning an Update GPRS Location Ack (IMSI, GPRS Subscriber Data (only if S6d interface is used)) message to the new 3G SGSN.
13) If the association has to be established, if Update Type indicates combined RA / LA update with IMSI attach requested, or if the LA changed with the routeing area update, the new SGSN sends a Location Update Request (new LAI, IMSI, SGSN Number, Location Update Type) to the VLR. Location Update Type shall indicate IMSI attach if Update Type in step 1 indicated combined RA / LA update with IMSI attach requested. Otherwise, Location Update Type shall indicate normal location update. When the SGSN does not provide functionality for the Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the VLR number is derived from the RAI. When the SGSN provides functionality for Intra Domain Connection of RAN Nodes to Multiple CN Nodes, the SGSN uses the RAI and a hash value from the IMSI to determine the VLR number. The 3G SGSN starts the location update procedure towards the new MSC/VLR upon receipt of the first Insert Subscriber Data message from the HLR in step 12). The VLR creates or updates the association with the 3G SGSN by storing SGSN Number. In networks that support network sharing, the Location Update Request includes the identity of the selected core network operator if the new 3G-SGSN has received this information from the RNS, as described in TS 23.251 [83].
  12）HLR确认GPRS的位置更新，并返回一个update GPRS location ACK（IMSI、GPRS签约数据(仅当S6d接口时才使用)）消息给new 3G-SGSN。

  13)如果关联需要建立，也就是更新类型指示了带有IMSI附着的联合的RA/LAU请求，或在RAU时发生了LA的变化，那么new 3G SGSN发送Location Update Request(新LAI、IMSI、SGSN编号、Location Update Type)给VLR。Location Update Type应指示为IMSI附着---如果在步骤1的更新类型指示的是带有IMSI附着请求的联合RA/LAU。除此以外，Location Update Type应指示为一个正常的Location Update。当SGSN不为多个CN节点提供到RAN节点的域内连接功能的话，VLR编号将从RAI获取。当SGSN提供这个功能时，SGSN使用RAI以及从IMSI得到的一个哈希函数来决定VLR编号。3G SGSN一旦在步骤12接收到从HLR来的Insert Subscriber Data消息，将开始到new MSC/VLR的位置更新流程。VLR通过存储SGSN编号来创建或更新与3G SGSN的关联。如果网络侧支持网络共享，并且new 3G-SGSN从RNS收到了这个信息的话，Location Update Request将指示选择的核心网络运营商ID，在TS23.251描述。

14) If the subscriber data in the VLR is marked as not confirmed by the HLR, the new VLR informs the HLR. The HLR cancels the old VLR and inserts subscriber data in the new VLR:
a) The new VLR sends an Update Location (new VLR) to the HLR.
b) The HLR cancels the data in the old VLR by sending Cancel Location (IMSI) to the old VLR.
c) The old VLR acknowledges with Cancel Location Ack (IMSI).
d) The HLR sends Insert Subscriber Data (IMSI, subscriber data) to the new VLR.
e) The new VLR acknowledges with Insert Subscriber Data Ack (IMSI).
f) The HLR responds with Update Location Ack (IMSI) to the new VLR.
   14)如果VLR上的签约数据标记为未得到HLR的确认，则new VLR要通知HLR。HLR取消在old VLR上的数据并在new VLR插入新的用户签约数据：
a）new VLR发送update location(new VLR)给HLR。
b) HLR发送cancel location(IMSI)消息给old VLR来取消其上的数据。
c）old VLR发送cancel location ack（IMSI)进行确认。
d）HLR发送插入签约用户数据(IMSI,签约数据）给new VLR。
e）new VLR发送insert subscriber data ack(IMSI)进行确认。
f）HLR发送update location ack（IMSI）给new VLR进行响应。

15) The new VLR allocates a new TMSI and responds with Location Update Accept (VLR TMSI) to the 3G SGSN. VLR TMSI is optional if the VLR has not changed.
16) The new 3G SGSN validate the MS's presence in the new RA. If due to roaming restrictions or access restrictions the MS is not allowed to be attached in the RA, or if subscription checking fails, the new 3G SGSN rejects the routeing area update with an appropriate cause. If the network supports the MOCN configuration for network sharing, the SGSN may, if the MS is not a 'Network Sharing Supporting MS', in this case decide to initiate redirection by sending a Reroute Command to the RNS, as described in TS 23.251 [83] instead of rejecting the routeing area update. If all checks are successful, the new 3G SGSN constructs MM and PDP contexts for the MS. The new 3G SGSN responds to the MS with a Routeing Area Update Accept (P TMSI, P TMSI signature, IMS voice over PS Session Supported Indication, Emergency Service Support) message. The IMS voice over PS Session Supported Indication is set as described in clause 5.3.8.
The Emergency Service Support indicator shall be included when going to UTRAN to inform the MS that Emergency PDP contexts are supported, i.e. the MS is allowed to request activation of emergency PDP context when needed.
  15）new VLR分配一个新的VLR TMSI并且响应location update accept(VLR TMSI)给3G SGSN。VLR TMSI是可选的，如果VLR没有发生变化的话。
  16）3G SGSN验证在新RA中MS的存在性。如果因为漫游限制或接入限制，MS不允许附着到RA，或者如果签约检查失败，则new 3G SGSN拒绝RAU并给出原因值。如果网络侧支持用于网络共享的MOCN配置，SGSN可以，如果MS是一个不支持网络共享的MS，在这里例子里来决定发送一个Reroute Command给RNS来发起一个重定向（在TS23.251描述）来代替拒绝RAU。如果所有检查都成功，new 3G SGSN构建MS的MM和PDP上下文。New 3G SGSN给MS响应一个RAU accept(P-TMSI、P-TMSI签名、IMS voice over PS会话指示指示、紧急业务支持）消息给MS。IMS voice over PS会话指示指示根据5.3.8章节描述设置。紧急业务支持指示是在UTRAN中通知MS支持紧急PDP上下文，也就是MS允许在需要的时候可以请求激活紧急PDP上下文。

17) The MS acknowledges the new P TMSI by returning a Routeing Area Update Complete message to the SGSN.
18) The new 3G SGSN sends TMSI Reallocation Complete message to the new VLR, if the MS confirms the VLR TMSI.
19) If the MS has uplink data or signalling pending it shall send a Service Request (P TMSI, RAI, CKSN, Service Type) message to the SGSN. Service Type specifies the requested service. Service Type shall indicate one of the following: Data or Signalling.
  17)MS返回RAU Complete消息给SGSN来确认对新P-TMSI的分配。

  18)New 3G SGSN发送TMSI Reallocation Complete消息给new VLR，如果MS确认了VLR TMSI的话。

  19)如果MS有pending状态的上行数据或信令，它应发送一个Service Request（P-TMSI、RAI、CKSN、Service Type）消息给SGSN。Service Type指明了请求的服务。Service Type应指示以下二者之一：数据或信令。

20) If the MS has sent the Service Request, the new 3G SGSN requests the SRNS to establish a radio access bearer by sending a RAB Assignment Request (RAB ID(s), QoS Profile(s), GTP SNDs, GTP SNUs, PDCP SNUs, UE-AMBR, MSISDN, APN, Charging characteristics) message to the SRNS. If Direct Tunnel is established the SGSN provides to the RNC the GGSN's Address for User Plane and TEID for uplink data. The PDCP sequence numbers are derived from the N PDU sequence numbers in step 4) and stored in the SGSN PDP contexts. The SRNS sends a Radio Bearer Setup Request (PDCP SNUs) message to the MS. The MS responds with a Radio Bearer Setup Complete (PDCP SNDs) message. The MS deducts PDCP-SND from its Receive N PDU Number by adding eight most significant bits "1". The SRNS responds with a RAB Assignment Response message. The SRNS shall discard all N PDUs tunnelled from the SGSN with N PDU sequence numbers older than the eight least significant bits of the PDCP SNDs received from the MS. Other N PDUs shall be transmitted to the MS. The MS shall discard all N PDUs with SNDCP sequence numbers older than the eight least significant bits of the PDCP SNUs received from the SRNS. Other N PDUs shall be transmitted to the SRNS. The SRNS negotiates with the MS for each radio bearer the use of lossless PDCP or not regardless whether the old 2G-SGSN used acknowledged or unacknowledged SNDCP for the related NSAPI or not. MSISDN, APN and Charging characteristics are optional parameters and only transferred if SGSN supports SIPTO at Iu-ps.
  20)如果MS发送了Service Request，new 3G-SGSN发送一个RAB Assignment Request（RAB ID、QOS Profile、GTP SNDs、GTP SNUs、PDCP SNUs、UE-AMBR、MSISDN、APN、计费特征）消息来请求SRNS来建立一个RAB。如果直接隧道建立，SGSN则给RNC提供上行数据的用户平面GGSN地址和TEID。PDCP序列号从N-PDU序列号派生出来并存储在步骤4的PDP上下文中。SRNS发送Radio Bearer Setup Request(PDCP SNUs)消息给MS.MS发送Radio Bearer Setip Complete（PDCP SNDs）消息做为响应。MS从收到的N-PDU Number加上8位最低有效位1来推导出PDCP-SND。SRNS然后响应一个RAB Assignment Response消息给SGSN。SRNS应检查从SGSN隧道发过来的所有N-PDU，如果发现其SNDCP序列号比SNRS收到的8位最低有效位还要老，则应将其丢弃。其他的MS将被传送给MS。MS也要做比较，如果发现收到的N-PDU的SNDCP序列号要比从SRNS收到的PDCP SNUs的8位最低有效位还要老，则应将其丢弃。SRNS和MS为每个无线承载来协商使用或不使用无损PDCP，而不管是否old 2G-SGSN为相关的NSAPI是使用确认模式还是非确认模式SNDCP。MSISDN、APN和计费特征是仅当在Iu-PS，SGSN支持SIPTO的时候的可选参数。

20a) If the SGSN established Direct Tunnel in step 20) it shall send Update PDP Context Request to the GGSN(s) concerned and include the RNC's Address for User Plane, downlink TEID for data and DTI to instruct the GGSN to apply Direct Tunnel specific error handling as described in clause 13.8. The GGSN(s) update the Address for User Plane and TEID for downlink data and return an Update PDP Context Response.
NOTE 1: The NSAPI value is carried in the RAB ID IE.
NOTE 2: The new SGSN may initiate RAB establishment after execution of the security functions (step 5), or wait until completion of the RA update procedure. For the MS, RAB establishment may occur anytime after the RA update request is sent (step 2).
  20a)如果SGSN在步骤20建立了直接隧道，它应发送Update PDP Context Request给相关的GGSN并且包含RNC用户平面地址、下行数据的TEID以及DTI来指示GGSN要应用直接隧道，相关的错误处理流程在章节13.8描述。GGSN更新用于下行数据的用户平面地址和TEID并返回Update PDP Context Response。

  注释1：NSAPI的值包含在RAB ID这个IE（信息元素）中。

  注释2：New SGSN可以在步骤5的安全功能执行之后发起RAB建立，或者等待直到RAU流程的完成。对于MS，RAB的建立可以在步骤2的RAU请求消息发送出去的任何时候发生。

If the new SGSN is unable to update the PDP context in one or more GGSNs, the new SGSN shall deactivate the corresponding PDP contexts as described in clause "SGSN-initiated PDP Context Deactivation Procedure". This shall not cause the SGSN to reject the routeing area update.
The PDP Contexts shall be sent from old to new SGSN in a prioritized order, i.e. the most important PDP Context first in the SGSN Context Response message. (The prioritization method is implementation dependent, but should be based on the current activity).
The new SGSN shall determine the Maximum APN restriction based on the received APN Restriction of each PDP context from the GGSN and then store the new Maximum APN restriction value.
  如果new SGSN不能同一个或多个GGSN更新PDP上下文、new SGSN应将相应的PDP上下文去激活。但这不应该导致SGSN拒绝RAU。

  PDP上下文应按照一定优先级顺序从old发向new SGSN，也就是最重要的PDP上下文第一个出现在SGSN Context Response消息中。（优先级的方法取决于具体的实现，但应基于当前的一些活跃事件来决定）。

  New SGSN应根据从GGSN接收到的每个PDP上下文的APN限制，来决定最大的APN限制，并且存储这个新的最大APN限制的值。

If the new SGSN is unable to support the same number of active PDP contexts as received from old SGSN, the new SGSN should use the prioritisation sent by old SGSN as input when deciding which PDP contexts to maintain active and which ones to delete. In any case, the new SGSN shall first update all contexts in one or more GGSNs and then deactivate the context(s) that it cannot maintain as described in clause "SGSN-initiated PDP Context Deactivation Procedure". This shall not cause the SGSN to reject the routeing area update.

  如果new SGSN不能支持从old SGSN接收到的相同数量的active PDP上下文,new SGSN应使用old SGSN发过来的优先级排序做为参考，以此来决定哪些PDP上下文应保持哪些则应删除。在任意场景，new SGSN应首先更新一个或多个GGSN中的所有上下文，并且将不能保持的上下文去激活。但这不应该导致SGSN拒绝RAU。

爱卫生

In this case, clause 6.13.2.2.1 applies except for steps 3, 4, 6, 7, 8 and 20, as well as clause-specific general statements stated below.
  在本例中，章节6.13.2.2.1中的流程步骤除了第3、4、6、7、8和20步，都适用于本例。因此不再列出，以下至列出不同部分。

Figure 55-2: steps 3, 4, 6, 7 for A/Gb mode to Iu mode Inter-SGSN Change using S4

Steps 3, 4, 6 and 7 are identical to the Gn/Gp case in clause 6.13.2.2.1, except that:
- Message SGSN Context Request is replaced by message Context Request;
- Parameter PDP Contexts is replaced by parameter EPS Bearer Contexts.
- MM Context and EPS Bearer Context when used at the S16 interface are defined by clause 13.2.2. For RAU between two S4-SGSNs, the old SGSN shall include the APN Restriction, CGI/SAI/RAI change support indication and Change Reporting Action in the Context Response message.
  步骤3，4，6，7和6.13.2.2.1中的基于Gn/Gp的例子是相同的，区别在于：

-- 消息SGSN Context Request被Context Request消息替代；

-- 参数PDP Context被参数EPS Bearer Context替代。

-- 在使用S16接口时的MM上下文和EPS承载上下文在13.2.2章定义。对于两个S4-SGSN之间的RAU，old SGSN应在Context Response消息中包含APN Restriction,CGI/SAI/RAI变更支持指示和变更报告指示。

8）Box（B）

Figure 55-3: step 8 for A/Gb mode to Iu mode Inter-SGSN Change using S4

NOTE: Steps a) and d) are common for architecture variants with GTP-based S5/S8 and PMIP-based S5/S8. For a PMIP-based S5/S8, procedure step (A1) is defined in TS 23.402 [90]. Steps b) and c) in Figure 55-3 concern GTP-based S5/S8.
   注释：步骤a和d对于使用GTP或PMIP的S5/S8来说都是公共的。对于基于PMIP的S5/S8，步骤A1在TS23.402定义。图例55-3的步骤b和c和基于GTP的S5/S8接口有关。

a) The new 3G SGSN sends a Modify Bearer Request (new SGSN Address, TEID, serving network identity, CGI/SAI, User CSG Information, RAT type, MS Info Change Reporting support indication) message to the Serving GW. The SGSN shall send the serving network identity to the Serving GW.
b) The Serving GW informs the P GW(s) about the change of Serving GW Address and TEID, as well as about the RAT type that e.g. can be used for charging, by sending the message Modify Bearer Request (Serving GW Address and TEID, RAT type) to the concerned P GW(s). If dynamic PCC is deployed, and RAT type information needs to be conveyed from the P GW to the PCRF, then the P GW shall send RAT type information to the PCRF as defined in TS 23.203 [88].
  a)new 2G SGSN发送Modify Bearer Request(new SGSN地址、TEID、服务网络ID、CGI/SAI、用户CSG信息、RAT类型、MS信息变化报告支持指示）消息给SGW。SGSN应发送服务网络ID给SGW。

  b）SGW通过发送Modify Bearer Request消息来通知PGW关于SGW地址和TEID的变化，以及RAT类型（例如可用于计费目的）。如果部署了动态PCC，则RAT类型信息将需要由PGW传递给PCRF，然后PGW应将RAT类型信息发送给在规范TS23.203中定义的PCRF。

c) Each P GW updates its context fields and returns a Modify Bearer Response (MSISDN, P GW address and TEID, Prohibit Payload Compression, MS Info Change Reporting Action, CSG Information Reporting Action) message. The Prohibit Payload Compression indicates that the SGSN should negotiate no data compression for this EPS Bearer context. MSISDN is included if available in the stored UE context.
d) The Serving GW updates the Address for User Plane and TEID for downlink data and return a Modify Bearer Response (Serving GW address and TEID, P GW address and TEIDs (for GTP based S5/S8) or GRE keys (for PMIP based S5/S8) at the PDN GW(s) for uplink traffic, CSG Information Reporting Action) message.
  c)每个PGW更新它的上下文字段并返回Modify Bearer Response (MSISDN、PGW地址和TEID、禁止payload压缩、MS信息变化报告行动、CSG信息报告行动）消息。禁止payload压缩指示SGSN不应为这个EPS承载上下文来协商数据压缩。MSISDN如果在存储的UE上下文中有的话也应提供。

  d) SGW更新下行数据的用户平面地址和TEID并返回一个Modify Bearer Response (SGW地址和TEID、PGW上用于上行流量的PGW地址和TEID（基于GTP的S5/S8）或GRE密钥（基于PMIP的S5/S8)，CSG信息报告行动）消息。

20 Box（C）

Figure 55-4: step 10 for A/Gb mode to Iu mode Inter-SGSN Change using S4

Step 10 is identical to the Gn/Gp case in clause 6.13.2.2.1, except that:
- Message SGSN Context Request is replaced by message Context Request;
- Parameter PDP Contexts is replaced by parameter EPS Bearer Contexts.
MM Context and EPS Bearer Context when used at the S16 interface are defined by clause 13.2.2.

  步骤10和章节6.13.2.2.1描述的基于Gn/Gp的case是相同的，除了以下部分：

-- 消息SGSN Context Request被Context Request消息替代；

-- 参数PDP Context被参数EPS Bearer Context替代。

  在S16接口使用的时候，MM上下文和EPS承载上下文在章节13.2.2定义。

yuws

看了 爱卫生发帖的时间，翻译+打字的速度比我单独看还要快。佩服

yonka

yuws 发表于 2012-6-29 10:24
看了 爱卫生发帖的时间，翻译+打字的速度比我单独看还要快。佩服

积累

我想爱总也不是临时现翻的吧

pine_向阳

学习、、、、、、、、