6.12 Service Request Procedure (Iu mode)

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6.12.0 General
The Service Request procedure is used by a 3G MS in PMM IDLE state to request the establishment of a secure connection to a 3G SGSN. The MS in PMM IDLE state initiates this procedure in order to send uplink signalling messages (e.g. Activate PDP Context Request), user data, or as paging response, or after the MS has regained UTRAN (or Iu mode GERAN) radio coverage. This procedure is also used by an MS in PMM CONNECTED state to request resource reservation for active PDP contexts.
In the context of this specification, the terms RNC refer also to a GERAN BSC when serving an MS in Iu mode.
   业务请求流程用于在PMM-IDLE状态的3G MS来请求建立到3G SGSN的安全连接。PMM-IDLE状态的MS发起这个流程的目的是为了发送上行信令消息(例如activate PDP Context Request),用户数据或作为一个寻呼响应,或者是在MS重新得到了UTRAN(或Iu模式的GERAN)的无线覆盖之后。这个流程也用于在PMM-CONNECTED状态的MS来请求为一个active的PDP上下文进行资源预留。
  规范中提到的一些术语，例如在Iu模式下为MS服务的RNC可以对应GERAN的BSC.
6.12.1 MS Initiated Service Request Procedure Using Gn/Gp
The MS in PMM IDLE state sends the Service Request message to the 3G SGSN in order to establish the PS signalling connection for the upper layer signalling or for the resource reservation for active PDP context(s). After receiving the Service Request message, the 3G SGSN may perform authentication, and it shall perform the security mode procedure. After the establishment of the secure PS signalling connection to a 3G SGSN, the MS may send signalling messages, e.g. Activate PDP Context Request, to the 3G SGSN, or the 3G SGSN may start the resource reservation for the active PDP contexts depending on the requested service in the Service Request message. An MS in PMM CONNECTED state also requests the resource reservation for the active PDP contexts through this procedure. An MS in PMM CONNECTED state also requests the resource reservation for preserved active PDP contexts that need to transfer data but have not been allocated resources in a previous Service Request.
  PMM-IDLE状态下的MS发送service request消息给3G SGSN,为上层信令或者为active的PDP上下文的资源预留建立PS的信令连接.在接收到service request消息后,3G SGSN可以执行鉴权,应执行安全模式流程。在建立了到3G SGSN的安全的PS信令连接之后,MS可以发送信令消息,例如Activate PDP Context Request给3G SGSN,或3G SGSN可以根据在service request消息中请求的业务来为active的PDP上下文来预留资源.一个PMM-CONNECTED状态的MS也可以通过这个流程为请求为一个active PDP上下文来预留资源。一个在PMM-CONNECTED状态的MS也可以请求为一个保持的active PDP上下文预留资源---这个保持的active PDP上下文是需要传递数据，但在之前的service request流程中还没有分配资源的一个上下文。

Figure 50: MS Initiated Service Request Procedure using Gn/Gp

NOTE 1: All steps in Figure 50 and 50a, except steps 6, 7 and 8, are common for architecture variants using Gn/Gp based interaction with GGSN and using S4 based interaction with S GW and P GW. For an S4 based interaction with S GW and P GW, procedure steps (A) are defined in clause 6.12.1A.
   注释1：在图例50和50a中的所有步骤,除了步骤6/7/8，对于基于Gn/Gp的架构和GGSN交互，还是对于基于S4的架构和SGW/PGW交互都是公共的。对于基于S4接口和SGW/PGW的交互,步骤(A)在章节6.12.1A定义。
1) The MS establishes an RRC connection, if none exists for CS traffic.
   The MS shall signal a cause that indicates emergency when it requests an RRC connection for PS emergency services, as defined in TS 25.331 [52].
   1）MS建立一个RRC连接,如果CS流量对应的RRC连接不存在的话。
  对于MS为PS紧急业务请求的RRC连接，MS应被告知一个原因，来指示紧急业务。在TS25.331描述。
2) The MS sends 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. When the Service Type indicates Data, the UE may also include PDP context activity information to indicate which PDP contexts need to transfer data. At this point, the SGSN may perform the authentication procedure.
   2)MS发送service request(P-TMSI,RAI,CKSN,Service Type)消息给SGSN.Service Type指明了请求的业务。Service Type应设置为数据或信令。当Service Type指示的是数据，则UE可以包含PDP上下文activity相关信息来指示哪一个PDP上下文需要传递数据。在这个点上，SGSN可以执行鉴权流程。
   If Service Type indicates Data, a signalling connection is established between the MS and the SGSN, and resources for active PDP context(s) are allocated, i.e. RAB establishment for the activated PDP context(s).
  如果Service Type指示为数据，一个信令连接在MS和SGSN之间建立,active的PDP上下文资源也分配，也就是激活的PDP上下文的RAB建立。
   If Service Type indicates Signalling, the signalling connection is established between the MS and the SGSN for sending upper-layer signalling messages, e.g. Activate PDP Context Request. The resources for active PDP context(s) are not allocated.
  如果Service Type指示为信令，那在MS和SGSN之间将为发送上层信令消息建立信令连接，例如Activate PDP Context Request。active PDP上下文的资源未分配。
   CSG ID is provided if the MS sends the Service Request message via a CSG cell or hybrid cell. CSG access mode is provided if the MS sends the Service Request message via a hybrid cell. If the CSG access mode is not provided but the CSG ID is provided, the SGSN shall consider the cell as a CSG cell.
  如果MS在CSG小区或混杂小区发送service request消息则提供CSG ID。如果MS通过一个混杂小区发送service request消息则提供CSG接入模式。如果提供了CSG ID但没有提供CSG接入模式，SGSN应认为这个是一个CSG小区。
   If a CSG ID is indicated and CSG access mode is "closed" or CSG access mode is not provided, and there is no subscription data for this CSG ID or the CSG subscription is expired, the SGSN rejects the Service Request with an appropriate cause. The UE shall remove the CSG ID of the cell where the UE has initiated the service request procedure from the Allowed CSG list, if present.
  如果指示了CSG ID并且CSG接入模式是"closed"或者CSG接入模式未提供,并且没有这个CSG签约数据或CSG相关签约数据已超时，SGSN应拒绝service request并带上合适的原因。UE应在允许的CSG列表中移除这个小区的CSG ID。
   For MSs with emergency PDP contexts, i.e. at least one PDP Context has an ARP value reserved for emergency services, and if CSG access restrictions do not allow the MS to get normal services, the SGSN shall deactivate all non-emergency PDP contexts and accept the Service Request.
   对于带有紧急PDP上下文的MS,也就是至少有一个PDP上下文带有为紧急业务预留的ARP值，并且CSG接入限制不允许MS来得到正常服务，SGSN应将所有非紧急PDP上下文去激活并接受这个service request。
   If LIPA is active for a PDP context and if the cell accessed by the MS does not link to the L-GW where the MS initiated the LIPA PDP context, the SGSN shall not request the establishment of the bearers of the LIPA PDP context from the RNC in step 4 and shall disconnect the LIPA PDP context by means of the SGSN-initiated PDP Context Deactivation Procedure according to clause 9.2.4.2.
  如果PDP上下文的LIPA是激活的，并且MS访问的小区不和MS发起LIPA PDP上下文的L-GW关联，SGSN不应请求在步骤4中，和RNC建立这个LIPA PDP上下文的承载，并应根据章节9.2.4.2的方法来发起SGSN-initiated PDP Context Deactivation流程来断开LIPA PDP上下文。
3) The SGSN shall perform the security functions if the MS in PMM-IDLE state initiated the service request.
  3）如果MS是在PMM-IDLE状态发起的service request，SGSN应执行安全功能。
4) If the network is in PMM-CONNECTED state and the Service Type indicates Data, the SGSN shall respond with a Service Accept message towards the MS, in case the service request can be accepted. In case Service Type indicates Data, the SGSN sends a Radio Access Bearer Assignment Request (NSAPIRAB ID(s), TEID(s), QoS Profile(s), SGSN IP Address(es), UE-AMBR, CSG Membership Indication, MSISDN, APN, Charging characteristics) message to re-establish radio access bearers for PDP contexts which do not have maximum bit rates for uplink and downlink of 0 kbit/s. If Direct Tunnel is established the SGSN provides to the RNC the GGSN's User Plane Address(es) and TEID(s) for uplink data instead of the SGSN's IP Address(es) and TEID(s). The SGSN may in addition use PDP context activity information provided by the UE in the Service Request to decide which RABs to set up. MSISDN, APN and Charging characteristics are optional parameters and only transferred if SGSN supports SIPTO at Iu-ps. When using S4, for RABs belonging to a PDN connection for Local IP Access the RAB Assignment Request message includes a Correlation ID for enabling the direct user plane path between the HNB and the L GW.
   4)如果网络侧的MS是在PMM-CONNECTED状态并且业务类型指示的是数据，SGSN应给MS响应一个service accept消息，一旦这个service request可以接受的话。如果service type指示的是数据，SGSN发送一个Radio Access Bearer Assignment Assignment Request(NSAPI, RAB ID,TEID、QOS Profile、SGSN IP地址、UE-AMBR、CSG成员指示、MSISDN、APN、计费特征）消息来为这个PDP上下文（上行方向没有MBR并且下行为0 kbit/s)来重建无线接入承载。如果直接隧道建立，SGSN则给RNC提供GGSN用户面地址和TEID用于上行数据，用于取代SGSN的IP地址和TEID。SGSN可以额外使用UE在service request消息中提供的PDP上下文activity信息来决定需要建立哪一个RAB。MSISDN,APN和计费特征是可选参数，并仅当SGSN支持Iu-ps接口的SIPTO时才传递。当使用S4，为本地IP接入的，属于一个PDN连接的RAB，那RAB Assignment Request消息包括了一个Correlation ID来使能在HNB和L GW之间的用户平面。
NOTE 1: In this release of the 3GPP specification the Correlation ID is set equal to the user plane PDN GW TEID that the S4-SGSN has received from the PDN GW.
NOTE 2: When using Gn-SGSN, the direct user plane path between the HNB and the L GW is enabled with the direct tunnel functionality described in clause 15.6.
  注释1：在这个3GPP版本规范里，Correlation ID设置为同S4-SGSN从PDN GW收到的用户平面PGW TEID相等。
  注释2：当使用Gn-SGSN，一个直接的用户面将在HNB和L GW间使用，直接隧道的功能描述见15.6。
  If the Service Request is performed via a hybrid cell, the CSG Membership Indication indicating whether the UE is a CSG member shall be included. Based on this information, the RAN can perform differentiated treatment for CSG and non-CSG members.
  If the MS is not allowed to access the cell where the MS initiated the service request due to CSG access restriction, the SGSN shall only request to establish radio access bearers for Emergency PDP contexts.
  如果Service Request是通过一个混杂小区执行的，"CSG Membership Indication"指示UE是否是一个CSG成员将被包含在消息中。根据这个信息，RAN可以执行CSG和非CSG成员的不同QOS待遇。
  如果MS因为CSG接入限制不允许接入这个它发起service request的小区，SGSN应只请求为紧急PDP上下文建立RAB。
5) The RNC indicates to the MS the new Radio Bearer Identity established and the corresponding RAB ID with the RRC radio bearer setup procedure.
  5)RNC通过RRC radio bearer setup消息指示MS，一个新的无线承载ID建立了以及相应的RAB ID。
6) SRNC responds with the Radio Access Bearer Assignment Response (RAB ID(s), TEID(s), QoS Profile(s), RNC IP Address(es)) message. The GTP tunnel(s) are established on the Iu interface.
  6)SRNC响应一个Radio Access Bearer Assignment Response(RAB ID,TEID,QOSProfile(s), RNC IP Address(es)) 消息。GTP隧道在Iu接口建立。
7) If the RNC returns a Radio Access Bearer Assignment Response message with a cause indicating that the requested QoS profile(s) can not be provided, e.g. "Requested Maximum Bit Rate not Available", the SGSN may send a new Radio Access Bearer Assignment Request message with different QoS profile(s). The number of re-attempts, if any, as well as how the new QoS profile(s) values are determined is implementation dependent. For each RAB re-established with a modified QoS profile, the SGSN initiates a PDP Context Modification procedure to inform the MS and the GGSN of the new negotiated QoS profile for the corresponding PDP context. If the SGSN established Direct Tunnel in step 4) it shall initiate a PDP Context Modification procedure to the GGSN and provide to the GGSN the RNC's Address for User Plane and TEID for Downlink data and shall include the DTI to instruct the GGSN to apply Direct Tunnel specific error handling procedure as described in clause 13.8.
8) The MS sends the uplink packet.
  7)如果RNC返回了Radio Access Bearer Assignment Response消息并带有一个原因，来指示请求的QOS profile不能提供,例如:"请求的MBR不可用",SGSN可以发送一个带有不同QOS profile的新的Radio Access Bearer Assignment Request消息。重试的次数，以及新的QOS profile值怎样决定的取决于具体的实现。对于每个带有修改的QOS profile重建的RAB，SGSN发起PDP Context Modification流程，来通知MS和GGSN关于某个PDP上下文新协商的QOS profile。如果SGSN在步骤4建立了直接隧道,它应发起一个到GGSN的PDP Context Modification流程，来给GGSN提供RNC的用户面地址和TEID用于下行数据，并且应携带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。
  8)MS发送上行报文。
For Service Type = Signalling, the MS knows that the Service Request message was successfully received in the SGSN when the MS receives the RRC Security Mode Control Command message.
For Service Type = Data, in PMM-IDLE, the MS knows that the Service Request was successfully received when the MS receives the RRC Security Mode Control Command message from the RNC; in PMM-CONNECTED state, the MS knows that the Service Request was successfully received when the MS receives the Service Accept message.
  对于Service Type=信令，当MS接收到RRC安全模式控制命令消息时，就知道Service Request消息已经被SGSN成功收到了。
对于Service Type=数据，在PMM-IDLE状态，当MS收到从RNC过来的RRC安全模式控制命令消息就知道Service Request消息已经被SGSN成功的收到了；在PMM-CONNECTED状态，当MS收到Service Accept消息就知道Service Request消息已经被SGSN成功的收到了。
NOTE 2: The reception of the Service Accept message does not imply the successful re-establishment of the RAB.
  注释2：Service Accept消息的接收并不暗示着RAB的重新建立的成功完成。
For any Service Type, in case the service request cannot be accepted, the network returns a Service Reject message to the MS with an appropriate cause value.
  对于任意类型的Service Type,一旦service request不能接受，网络侧返回一个service rejuect消息给MS并带上合适的原因值。
For Service Type = Data, in case the SGSN fails to re-establish RAB(s) for the PDP context(s), the SGSN determines if an SM procedure, such as SGSN-Initiated PDP Context Modification or PDP Context Deactivation, should be initiated. The appropriate action depends on the QoS profile of the PDP context and is an operator choice.
  对于service type=数据，一旦SGSN为PDP上下文重建RAB失败，SGSN决定一个SM（会话管理）流程，例如SGSN发起的PDP Context Modification或PDP Context Deactivation应被触发。适当的行动取决于PDP上下文的QOS profile并且这个是一个运营商的选择。
For each PDP context using streaming or conversational traffic class with maximum bit rate for uplink and downlink of 0 kbit/s the MS starts the MS-Initiated PDP Context Modification procedure or the MS-Initiated PDP Context Deactivation procedure to inform the SGSN whether to re-activate or to delete the PDP contexts. If the PDP context has been deactivated locally in the MS, the MS shall not perform the PDP context deactivation procedure for this PDP context because the list of active and inactive PDP contexts is included in the Service Request Message sent prior to the network.
  对于在上行带有MBR下行为0 kbit/s的使用流或会话类业务的每个PDP上下文，MS开始MS-Initiated PDP Context Modification流程或MS-Initiated PDP Context Deactivation流程来通知SGSN，是否要重新激活或删除PDP上下文。如果PDP上下文在MS本地去激活，MS则不应为这个PDP上下文执行PDP上下文去激活流程，因为之前active和inactive的PDP上下文列表已经在之前的Service Request消息中发送给了网络侧。

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The procedures described in figure 50a shows only the steps, which are different from the Gn/Gp variant of the procedure described in clause 6.12.1. due to the use of S4.
   在图例50a的流程中，仅仅显示了因为S4接口的使用，和6.12.1基于Gn/Gp接口的流程中不同的地方。

Figure 50a: UE Initiated Service Request Procedure using S4

NOTE 1: All steps in figures 50a and 51a, are common for UE and Network initiated procedure using S4. For a PMIP-based S5/S8, procedure steps (B1) are defined in TS 23.402 [90].

  注释1：在图例50a和51a中的所有步骤，当使用S4接口时，对UE和网络侧发起的流程来说，都是公共的（即通用的）。对于基于PMIP的S5/S8接口，流程步骤B1在TS23.402定义。
A) If the RNC returns a Radio Access Bearer Assignment Response message with a cause indicating that the requested QoS profile(s) can not be provided, e.g. "Requested Maximum Bit Rate not Available", the SGSN does not send any new Radio Access Bearer Assignment Request message with different QoS profile(s), the RAB is not established. For each established RABs, the SGSN sends Modify Bearer Request messages to the Serving GW (Downlink S4/S12 TEID). If the S GW receives a DL packet for an unaccepted bearer, the S GW drops the DL packet and does not send a Downlink Data Notification to the MME. For the established RABs, if the SGSN established Direct Tunnel it includes the RNC's Address for User Plane TEID for downlink data and DTI. If Direct Tunnel is not used, the SGSN includes SGSN Address for User Plane and TEID for downlink data. The Serving GW is now able to transmit downlink data towards the UE. If there is no Direct Tunnel the SGSN sends downlink packet.
   If any EPS bearers are to be released the SGSN triggers the bearer release procedure as specified in clause 9.2.4.2.

  A)如果RNC返回了一个带有原因值指示请求的QOS profile不能提供的Radio Access Bearer Assignment Response消息，例如"请求的MBR不可用",SGSN不会发送带有不同QOS profile的新的Radio Access Bearer Assignment Request消息，RAB将不能建立。对于每个已经建立的RABs，SGSN发送Modifu Bearer Request消息给SGW（下行S4/S12 TEID）。如果SGW从一个不可接受的承载中接收到了下行数据包，SGW将丢弃下行数据包并且不给MME发送下行数据通知。对于已经建立的RABs，如果SGSN建立了直接隧道，它将包含RNC为下行数据设立的用户面TEID和地址，以及DTI。如果直接隧道未使用，SGSN将在消息中包含用于下行数据的用户面SGSN地址和TEID。SGW现在就可以传送下行数据给UE了。如果没有直接隧道建立的话，那SGSN将开始发送下行数据。

  如果任何EPS承载将要被释放，则SGSN根据章节9.2.4.2的描述出发承载释放流程。
B) If the RAT Type has changed compared to the last reported RAT Type, the Serving GW shall send the Modify Bearer Request message (RAT Type) to the PDN GW. The PDN GW sends the Modify Bearer Response to the Serving GW.
NOTE 2: PCC interactions between the PDN GW and the PCRF are documented in TS 23.401 [89]
C) The Serving GW acknowledges by sending Modify Bearer Response (SGW address for user plane and uplink S4 GTP-U TEID) to the SGSN.
   B）如果RAT类型和上一次报告的RAT类型发生了变化，SGW应发送Modify Bearer Request消息(RAT Type)给PGW,PGW发送Modify Bearer Response消息给SGW.

  注释2：在PGW和PCRF之间的PCC交互在TS23.401定义。

  C）SGW发送Modify Bearer Response(SGW用于上行数据的用户面地址和S4 GTP-U TEID)给SGSN进行确认。

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When the 3G SGSN receives a downlink packet (e.g. Request PDP Context Activation, Mobile-terminated SMS, user data) for an MS in PMM IDLE state, the 3G SGSN sends a paging request to RAN. The paging request triggers the Service Request procedure in the MS.
   当3G SGSN接收到下行数据包(例如请求PDP上下文激活、手机接收的短信、用户数据)，要发送给PMM-IDLE状态的MS,3G SGSN发送寻呼请求给RAN.寻呼请求将出发MS的Service Request流程。

Figure 51: Network Initiated Service Request Procedure

NOTE 1: All steps in figure 51, except Procedure steps (A) and (B), are common for architecture variants using Gn/Gp based interaction with GGSN and using S4 based interaction with S GW and P GW.
NOTE 2: Procedure steps B (step 7) in figure 51 above are common for MS and Network initiated service request using S4 and are described in clause 6.12.1A. Procedure steps (A) are defined in clause 8.2.4.1A when S4 is used.
  注释1：所有在图例51的步骤，除了A和B以外，对于基于Gn/Gp接口和GGSN的交互的架构，还是对于基于S4接口和SGW/PGW的交互的架构，都是公共的步骤流程。

注释2：图例51中的流程步骤B，对于在章节6.12.1A描述的使用S4接口的MS和网络侧发起的service request也是公共的。流程步骤A当使用S4接口时的说明，在章节8.2.4.1A中定义。

If a LIPA PDP context exists, when the L-GW receives the downlink data for an MS in PMM-IDLE state, the L GW sends the first downlink user packet to the SGSN and buffers all other downlink user packets. When S4 is used, the L-GW sends the first downlink user packet to Serving GW and the Serving GW will trigger the SGSN to page the UE.
  如果一个LIPA PDP上下文存在，当LGW接收到PMM-IDLE状态MS的下行数据，LGW发送一个下行用户数据报文给SGSN并且缓存其他的下行用户数据。当使用S4接口时，LGW发送第一个下行用户数据给SGW并且SGW将出发SGSN去寻呼UE。

1) The SGSN receives a downlink PDP PDU for an MS in PMM IDLE state.
2) The SGSN sends a Paging message to the RNC. The RNC pages the MS by sending a Paging message to the MS. See clause "PS Paging Initiated by 3G SGSN without RRC Connection for CS" for details.
3) The MS establishes an RRC connection if none exists for CS traffic.

  1）SGSN接收到一个PMM-IDLE状态的MS的一个下行PDP PDU。

2）SGSN发送一个寻呼消息给RNC。RNC发送寻呼消息给MS来寻呼这个MS。参考章节"PS Paging Initiated by 3G SGSN without RRC Connection for CS"得到细节描述。

3）MS上，如果不存在为CS流量的RRC连接的话，则建立一个RRC连接。
4) The MS sends a Service Request (P TMSI, RAI, CKSN, Service Type) message to the SGSN. Service Type specifies Paging Response. The Service Request is carried over the radio in an RRC Direct Transfer message and over the Iu interface in the RANAP Initial MS message. At this point, the SGSN may perform the authentication procedure. The SGSN knows whether the downlink packet requires RAB establishment (e.g. downlink PDU) or not (e.g. Request PDP Context Activation or Mobile-terminated SMS).
   CSG ID is provided if the MS attaches via a CSG cell or hybrid cell. CSG access mode is provided if the MS sends the Service Request message via a hybrid cell. If the CSG access mode is not provided but the CSG ID is provided, the SGSN shall consider the cell as a CSG cell.
   If a CSG ID is indicated and CSG access mode is "closed" or CSG access mode is not provided, and there is no subscription data for this CSG ID or the CSG subscription is expired, the SGSN rejects the Service Request with an appropriate cause. The MS shall remove the CSG ID of the cell where the MS has initiated the service request procedure from the Allowed CSG list, if present.
   For MSs with emergency PDP contexts, i.e. at least one PDP Context has an ARP value reserved for emergency services, and if CSG access restrictions do not allow the MS to get normal services, the SGSN shall deactivate all non-emergency PDP contexts and accept the Service Request.
   4）MS发送Service Request(P-TMSI,RAI,CKSN,Service Type)消息给SGSN.Service Type指明了这是一个寻呼响应。Service Request通过空中接口承载，并封装到RRC Direct Transfer消息中，并做为Iu接口的RANAP协议的RANNAP PDU，做为初始MS消息来传送。在这个点上，SGSN可以执行鉴权流程。SGSN知道是否这个下行数据报文需要RAB建立(例如下行PDU)或不需要建立(例如请求PDP上下文建立或MS接收的短信).

  CSG ID当MS通过一个CSG小区或混杂小区附着时则应提供。CSG接入模式是当MS在一个混杂小区内发送service request消息时则应提供。如果CSG接入模式没有提供，但提供了CSG ID，SGSN应认为这个小区是一个CSG小区。

  如果指示了CSG ID并且CSG接入模式是"closed"或者CSG接入模式未提供,并且没有它的签约数据或CSG相关的签约数据超时，SGSN应拒绝service request并带上合适的原因。UE应在允许的CSG列表中移除这个小区的CSG ID。

  对于带有紧急PDP上下文的MS,也就是至少有一个PDP上下文带有为紧急业务预留的ARP值，并且CSG接入限制不允许MS来得到正常服务，SGSN应将所有非紧急PDP上下文去激活并接受这个service request。

5) The SGSN shall perform the security mode procedure. 5)SGSN应执行安全模式流程。
6) If resources for the PDP contexts are re-established, the SGSN sends a Radio Access Bearer Assignment Request (RAB ID(s), TEID(s), QoS Profile(s), SGSN IP Address(es), UE-AMBR, CSG Membership Indication, MSISDN, APN, Charging characteristics) message to the RNC. If Direct Tunnel is established the SGSN provides to the RNC the GGSN's User Plane Address and TEID for uplink data. The RNC sends a Radio Bearer Setup (RAB ID(s)) to the MS. The MS responds by returning a Radio Bearer Setup Complete message to the RNC. The RNC sends a Radio Access Bearer Assignment Response (RAB ID(s), TEID(s), RNC IP Address(es)) message to the SGSN in order to indicate that GTP tunnels are established on the Iu interface and radio access bearers are established between the RNC and the MS. If the RNC returns a Radio Access Bearer Assignment Response message with a cause indicating that the requested QoS profile(s) can not be provided, e.g. "Requested Maximum Bit Rate not Available", the SGSN may send a new Radio Access Bearer Assignment Request message with different QoS profile(s). The number of re-attempts, if any, as well as how the new QoS profile(s) values are determined is implementation dependent. MSISDN, APN and Charging characteristics are optional parameters and only transferred if SGSN supports SIPTO at Iu-ps.
   If the Service Request is performed via a hybrid cell, the CSG Membership Indication indicating whether the UE is a CSG member shall be included. Based on this information the RAN can perform differentiated treatment for CSG and non-CSG members.
   If the MS is not allowed to access the cell where the MS initiated the service request due to CSG access restriction, the SGSN shall only request to establish radio access bearers for Emergency PDP contexts.
  6）如果这个PDP上下文的资源需要重建，SGSN发送RAB Assignment Request（RAB ID、TEID、QOS Profile、SGSN地址、UE-AMBR、CSG成员指示、MSISDN、APN、计费特征）消息给RNC。如果要建立直接隧道，SGSN则给RNC提供GGSN用户面地址和TEID用于上行数据。RNC发送Radio Bearer Setup(RAB ID)消息给MS。MS发送一个Radio Bearer Setup Complete消息给RNC做为响应。RNC发送RAB Assignment Response(RAB ID、TEID、RNC地址）消息给SGSN，用于指示这个GTP隧道已经在Iu接口建立，并且RAB也已经在RNC和MS之间建立。如果RNC返回了一个RAB Assignment消息并带有一个原因值说明请求的QOS profile不能提供，例如"请求的MBR不可用",SGSN可以发送一个新的带有不同QOS profile值的RAB Assignment请求消息给RNC。重试的次数，以及新的QOS profile的值怎样取值，取决于具体的实现。MSISDN、APN和计费特征是只有在Iu-PS下，SGSN支持SIPTO时，才带的可选字段。

  如果Service Request是通过一个混杂小区执行的，"CSG Membership Indication"指示UE是否是一个CSG成员将被包含在消息中。根据这个信息，RAN可以执行CSG和非CSG成员的不同QOS待遇。
  如果MS因为CSG接入限制不允许接入这个它发起service request的小区，SGSN应只请求为紧急PDP上下文建立RAB。

7) For each RAB re-established with a modified QoS profile, the SGSN initiates a PDP Context Modification procedure to inform the MS and the GGSN of the new negotiated QoS profile for the corresponding PDP context. If SGSN established Direct Tunnel in step 6) it shall initiate a PDP Context Update procedure to the GGSN and provide to the GGSN the RNC's Address for User Plane and TEID for Downlink data and shall include the DTI to instruct the GGSN to apply Direct Tunnel specific error handling procedure as described in clause 13.8.
   7)对于每一个带有修改的QOS profile要求重建的RAB,SGSN发起一个PDP Context Modification流程来通知MS和GGSN关于相应的PDP上下文的新的协商的QOS profile。如果SGSN在第6步建立了直接隧道，它将发起PDP Context Update流程到GGSN，并给GGSN提供RNC上用户下行数据的用户面地址和TEID，并应包含DTI来指示GGSN要应用直接隧道。相关错误处理流程在章节13.8描述。

8) The SGSN sends the downlink packet. For a LIPA PDP context, after the MS enters connected mode, the packet buffered in SGSN/Serving GW is forwarded to the HNB if it is the same cell where the L-GW is collocated and the packets buffered in the L-GW are forwarded to the HNB on the direct path. If the MS enters connected mode at a different cell than the one where the L-GW is collocated, the SGSN shall deactivate the LIPA PDP context and the packet buffered in the SGSN/Serving GW is dropped.
   For Service Type = Page Response, the MS knows that the Service Request message was successfully received in the SGSN when the MS receives the RRC Security Mode Control Command message.
If the SGSN fails to re-establish RAB(s) for the PDP context(s), the SGSN determines if an SM procedure, such as SGSN-Initiated PDP Context Modification or PDP Context Deactivation, should be initiated. The appropriate action depends on the QoS profile of the PDP context and is an operator choice.
   8)SGSN发送下行数据报文。对于一个LIPA PDP上下文，在MS进入连接状态之后，如果LGW所在的小区和缓存在LGW上的数据包到将转发给HNB的直接路径在相同小区的话，缓存在SGSN/SGW中的数据包将转发给HNB(Home NodeB)。如果MS进入连接状态，但和LGW所在的小区不同，SGSN应去激活LIPA PDP上下文，并且缓存在SGSN/SGW的数据报文将被丢弃。

  对于Service Type=寻呼响应，当MS收到RRC Serurity Mode Control Command消息时，MS就知道Service Request消息成功的被SGSN收到了。

  如果SGSN为这个PDP上下文重建RAB失败，SGSN决定一个SM（会话管理）流程，例如SGSN发起的PDP Context Modification或PDP Context Deactivation应被触发。适当的行动取决于PDP上下文的QOS profile并且这个是一个运营商的选择。

张沿

楼主厉害

wuwu

懒人的福，不想看E文，就看爱总的

yuws

看来不喜欢看E文的人不止我啊

paul

今天才看到这个帖子，沉了可惜，应该置顶。

paul

爱总，问个问题：
什么情况下ms发送activate pdp ctx request，需要先发service requset？
如果是ms先attach上的话，是没有service request的，直接就发了activate pdp ctx request。
出了使用service request发送paging response外，我对通过service request发送signalling 和 data的场景还是有些不太明白

爱卫生

paul 发表于 2013-11-29 10:50
爱总，问个问题：
什么情况下ms发送activate pdp ctx request，需要先发service requset？
如果是ms先att ...

什么情况下ms发送activate pdp ctx request，需要先发service requset？

在Iu连接已经释放的情况下要发，也就是移动性管理状态为PMM-IDLE状态时要发。

如果是ms先attach上的话，是没有service request的，直接就发了activate pdp ctx request。

是，因为如果attach上的话，Iu连接还没有释放，所以可以直接飞activate pdp context request。不用发service request。但如果attach后过一段时间，那iu连接会释放，那还是要发service request的。

出了使用service request发送paging response外，我对通过service request发送signalling 和 data的场景还是有些不太明白

service request流程就是重建空口的连接来传送信令或用户数据。如果已经是连接态（pmm-connected）则不用发service request。

imwoohan

爱卫生 发表于 2013-11-30 17:46
什么情况下ms发送activate pdp ctx request，需要先发service requset？在Iu连接已经释放的情况下要发，也 ...

其实，service request的类型为数据的时候，里面的PDP Context Status的值其实很重要，这个时候，PDP Context Status里面的NASPI的值指示着UE要求那个对应PDP Context 要开始工作，也就是从IDLE状态变成Active状态。比方说有的app用的是更高的Qos，而UE仅仅想让这个更高qos的PDP Context 工作，那么 service request就可以把这个PDP Context 对应的RAB(也就是NASPI的值)置1，而其他的NASPI都置为0。

zxtcinderella

非常感谢，不用看E文了！

hust104

竟然有详细的翻译，相见恨晚呀。

hou3331

爱总，麻烦帮忙解答下哦：
对于6.12.2 Network Initiated Service Request Procedure using Gn/Gp流程，通过CN想iu release 的UE发送下行数据，SGSN向RNC创建了一条RAB，刚好此刻UE发送了一个service request（service type：data），6.12.1 MS Initiated Service Request Procedure Using Gn/Gp

此时SGSN的行为是可以重复利用原先创建的RAB吗？还是需要先把刚才的rab release然后在rab assignment 创建？

hou3331

后来明白了，这是个异常情况，UE发送service request（data）是请求建立RAB的