METHOD AND APPARATUS FOR PROVIDING CIRCUIT SWITCHED DOMAIN SERVICES OVER A PACKET SWITCHED NETWORK
A method of determining a domain mode for a mobile station operating in either a circuit-switched domain or a packet-switched domain. A first domain mode is determined, and then a determination is made whether to rove from the first domain mode to a second domain mode. The determination may be made by a Packet Mobile Switching Center (PMSC) when, for example, the mobile station moves between Routing Areas. Alternatively, the mobile station may make the determination based, for example, on pre-provisioned selection criteria. The mobile station derives a Fully Qualified Domain Name (FQDN) based on a cell identifier of a current cell and uses the FQDN in a DNS query to obtain the IP address of the PMSC.
This application claims the benefit of U.S. Provisional Application No. 60/884,914 filed Jan. 15, 2007, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTIONThe present invention relates to circuit switched domain services. More particularly, the present invention relates to providing circuit switched (CS) domain services over a packet switched (PS) network.
When introducing LTE (Long Term Evolution)—the next generation radio access in 3GPP—there are only packet bearers available. This means that the wide range of services currently offered within the CS domain can not be used by a terminal using LTE-connectivity, unless the terminal either shifts to another radio access or is equipped with a second transceiver permitting parallel access to the CS-domain present in 2G and 3G networks. Examples of existing services are:
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- Prepaid
- Regularity equipments for identity signaling
- Legal interception
- 0800 calls, free calls
- Announcements
- Premium number calls
- Home Zone
- Sound Logo
- Call Barrings
- MultiSIM
- Standardized supplementary services
The basic assumption when introducing LTE is that the telecommunication service will be provided by the IMS (IP Multimedia Subsystem) system.
BRIEF SUMMARY OF THE INVENTIONThe present invention generally describes a method of determining a domain mode for a mobile station. In one embodiment, a first domain node is determined. A determination is made whether to rove from the first domain mode to a second domain mode according to predefined roving criteria.
The present invention also generally describes a method of performing Packet Mobile Switching Center discovery for a mobile station. A Fully Qualified Domain Name is derived based on a cell identifier of a current cell. The derived Fully Qualifed Domain Name is used to determine an Internet Protocol Address of a Packet Mobile Switching Center.
In the following section, the invention will be described with reference to exemplary embodiments illustrated in the figures, in which:
As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a wide range of applications. Accordingly, the scope of patented subject matter should not be limited to any of the specific exemplary teachings discussed above, but is instead defined by the following claims.
The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawing.
For the purposes of the present invention, the following terms and definitions apply:
24.008 over 3GPP PS network: A service which allows a terminal to make use of the CS call control also over a 3GPP packet switched network.
24.008 over 3GPP PS network Mode: MS mode of operation where the NAS layers communicate through the U8-CSR entity.
24.008 over 3GPP PS network PMSC: The target MSC, or rather PMSC when handing over from CS domain to packet domain entering the 24.008 over 3GPP PS network Mode.
24.008 over 3GPP PS network supporting PMSC: The PMCS that a MS will rove into when entering the 24.008 over 3GPP PS network Mode.
3GPP PS network: Radio and core part of the 3GPP Packet Switched service.
CS Domain: The domain where Circuit Switched services are executed. This domain can be based on IP in the core network, but on the radio access the resources are circuit based.
CS Domain mode: MS mode of operation where the CS related NAS layers communicate through either the GERAN RR or the UTRAN RRC entities, thus operating in the normal CS Domain. When GERAN RR is used, the BSS is connected to the CN using the standardized A-interface. When UTRAN RRC is used, the RNS is connected to the CN using the standardized Iu-CS interface.
Discovery procedure: The process by which the MS discovers which PMSC to Rove into.
Handover: Mobile station engaged in a call moves between 3GPP CS access networks and 24.008 over 3GPP PS networks.
Handover in: mobile station moves from 3GPP CS access network to 24.008 over 3GPP PS network
Handover out: mobile station moves from 24.008 over 3GPP PS network to 3GPP CS access network
PMSC: Packet MSC, the network function needed to support the 24.008 over 3GPP PS network service.
Supporting PMSC: The PMSC the MS Roves into
Rove in: mobile station reselects from 3GPP CS access network to 24.008 over 3GPP PS network
Rove out: mobile station reselects from 24.008 over 3GPP PS network to 3GPP CS access networks
Roving: action of re-selection between 3GPP CS access and 24.008 over 3GPP PS network for a mobile station in idle mode
Seamless: free from noticeable transitions (i.e. no end-user action is required; speech interruptions are short; service interruptions are short; incoming calls are not missed; packet sessions are maintained; services work identically)
For the purposes of the present invention, the following abbreviations apply:
AMR Adaptive Multi-Rate
AS Access Stratum
BSS Base Station Subsystem
BSSGP Base Station System GPRS Protocol
BSSMAP Base Station System Management Application Part
CC Call Control
CGI Cell Global Identity
CM Connection Management
CN Core Network
CS Circuit Switched
CSR Circuit Switched Resources
CTM Cellular Text Telephone Modem
DNS Domain Name System
DTM Dual Transfer Mode
ETSI European Telecommunications Standards Institute
FQDN Fully Qualified Domain Name
GAD Geographical Area Description
GAN Generic Access Network
GERAN GSM EDGE Radio Access Network
GGSN Gateway GPRS Support Node
GMM/SM GPRS Mobility Management and Session Management
GPRS General Packet Radio Service
GSM Global System for Mobile communications
GSN GPRS Support Node
HLR Home Location Register
HPLMN Home PLMN
HSPA High Speed Packet Access
IETF Internet Engineering Task Force
IMEISV International Mobile station Equipment Identity and Software Version number
IMS IP Multimedia Subsystem
IMSI International Mobile Subscriber Identity
IP Internet Protocol
ISIM IMS Subscriber Identity Module
LA Location Area
LAI Location Area Identity
LLC Logical Link Control
LTE Long Term Evolution
MAC Medium Access Control
MM Mobility Management
MS Mobile Station
MSC Mobile Switching Center
MTP1 Message Transfer Part layer 1
MTP2 Message Transfer Part layer 2
MTP3 Message Transfer Part layer 3
NAS Non-Access Stratum
PDP Packet Data Protocol
PDU Protocol Data Unit
PLMN Public Land Mobile Network
PMSC Packet MSC
PSAP Public Safety Answering Point
NOTE: A PSAP is an emergency services network element that is responsible for answering emergency calls.
PSTN Public Switched Telephone Network
QoS Quality of Service
RA Routing Area
RAC Routing Area Code
RAI Routing Area Identity
RAT Radio Access Technology
RLC Radio Link Control
ROHC Robust Header Compression
RRC Radio Resource Control
RTCP Real Time Control Protocol
RTP Real Time Protocol
SCCP Signaling Connection Control Part
SGSN Serving GPRS Support Node
SIM Subscriber Identity Module
SMLC Serving Mobile Location Center
SMS Short Message Service
SNDCP Sub-Network Dependent Convergence Protocol
SS Signaling Subsystem
TFO Tandem Free Operation
TrFO Transcoder Free Operation
TTY Text Telephone or TeletYpewriter
UDP User Datagram Protocol
UMTS Universal Mobile Telecommunication System
VLR Visited Location Register
VPLMN Visited Public Land Mobile Network
Control plane information 180 is tunneled through packet switched network 140 to network controller 194. Network controller 194 may be a stand-alone unit or may be a component of mobile switching center server (MSC-S) 196. User plane information 190 is tunneled through packet switched network 140 to inter working unit (IWU) 192. IWU 192 may be a stand-alone unit or may be a component of circuit switch domain media gateway (CS-MGW) 198. Network controller 194, MSC-S 196, IWU 192, and CS-MGW 198 are all located in a packet mobile switching center (not shown).
All other possible PS traffic 182 would be transported towards packet data network 150. The figure shows LTE 130 as an example for the 3GPP PS access being used. Other possibilities are e.g. Evolved GSM/GPRS, UMTS/HSPA and WiMax. The LTE example of
Packet mobile switching center (PMSC) 225 has new functionality as compared with a mobile switching center (MSC). PMSC 225 is able to handle the 24.008 over 3GPP PS network service. In one embodiment, PMSC 225 handles interface (U8) 217, which is an interface between mobile station 205 and PMSC 225 over PS network 220. In one embodiment, PMSC 225 is able to request certain IP Quality of service class from the PS network. PMSC 225 may be divided into 4 functional components: the MSC server 240, a network controller 230, e.g., 24.008 over 3GPP network Controller (8PSC), an Inter Working Unit (IWU) 235 and a media gateway 245, e.g., CS domain Media Gateway (CS-MGW). Network controller 230 and IWU 235 may be stand alone units or may be part of MSC-Server 240 and CS-MGW 245, respectively.
Network controller 194, 230 terminates the control plane part of the U8 interface (i.e. the U8c interface). Network controller 230 optionally authenticates the user, e.g., MS 205, before any signaling towards the Iu-CS interface is attempted. Network controller 230 is also responsible for requesting resources from Policy and Charging Rules Function (PCRF) 250.
IWU 192, 235 terminates the user plane part of the U8 interface (i.e. the U8u interface) and is responsible for repacking of the media stream from Real Time Protocol (RTP) to Nb (Nb is the interface between media gateways in the 3GPP CS domain) framing in RTP. Optionally, if an Asynchronous Transfer Mode (ATM) based interface on Iu-CS is used, IWU 235 will also do media gatewaying between ATM and IP.
In addition to handling control information from network controller 230, MSC server 240 operates to handle control information from a mobile station via CS-core 215 and CS access 210 and media control information, Mc, from CS-MGW 245 as detailed in related specifications of the 3GPP standard. In addition to handling user plane information from IWU 235, Circuit Switched domain Media Gateway (CS-MGW) 245 also operates to handle media information as detailed in related specifications of the 3GPP standard.
MS 205 interfaces to network 210 using Um for GERAN and Uu for UMTS Terrestrial Radio Access Network (UTRAN). The term U(x) is used to denote both Um and Uu without excluding even more interfaces.
The A and Iu interfaces are the two standard CS domain interfaces between Access Network 210 and Core Network 215. The A-interface is used between GERAN 210 and MSC 240 and the Iu-CS interface can be used either between GERAN 210 and MSC 240 or between UTRAN 210 and MSC 240.
The Rx interface is the interface used by applications towards PCRF 250. It is not foreseen that this application will have any additional functionality needs on the interface.
Interface 217, i.e., U8-interface, is divided on user plane U8u 180 and control plane U8c 190. Interface 217 carries all the control and user plane information needed to e.g. Rove; and set-up, maintain, and clear 24.008 CS calls over a 3GPP PS network, e.g. network 140, 220. U8-interface 217 is between the MS 110, 205 and the PMSC 225. The interface supports all CS defined services within 3GPP 24.008, such as mobility, basic call and supplementary services.
The Gi interface is the IP-based interface coming out from the 3GPP PS network. Another name for the Gi interface is SGi and is used in the SAE/LTE 3GPP specifications. On functional level there is no real difference between Gi and SGi. In one embodiment, the Gi interface (or the SGi) is implemented using AGW 144 (which can be broken up into S GW and PDN GW according to current standardisation). In another embodiment using a GPRS PS network, the Gi interface is implemented using GGSN. In yet another embodiment using WiMAX, architecture the AGW can be translated into the Access Service Network Gateway and Home Agent. In the WiMAX architecture there are no name corresponding to the Gi and SGi reference points.
The embodiment shown in
UDP provides transport for the U8 Circuit Switched Resources (U8-CSR) 217 between MS 110, 205 and PMSC 225. In one embodiment, U8-CSR is based on GAN (Generic Access Network) tunneling protocols as defined in 3GPP TS 43.318 and 44.318. The U8-CSR protocol manages the IP connection and performs functionality equivalent to the GSM-RR protocol. Protocols, such as mobility management (MM) and above, e.g., CC/SS/SMS, are carried transparently between MS 110, 205 and PMSC 225. The IP address of MS 110, 205 is used by PMSC 225 to communicate with the MS 110, 205 for the 24.008 over 3GPP PS network service.
The U8-CSR protocol provides a resource management layer, which is equivalent to the GSM-RR or UTRAN-RRC and provides the following functions: discovery, i.e. selecting the 24.008 over 3GPP PS network supporting PMSC; setup of IP bearer resources for CS service between the MS and PMSC (8PSC functional entity); handover support between UTRAN/GERAN and 24.008 over 3GPP PS network; and functions such as paging, ciphering configuration, classmark change, etc.
The MS enters 24.008 over PS network mode when the MS switches the serving RR entity to U8-CSR and the SAP between the MM and the U8-CSR is activated. While the MS remains in 24.008 over 3GPP PS network mode it performs normal and periodic Location Updates and application level keep-alive with the 24.008 over 3GPP PS network supporting PMSC.
The MS moves from the U8-CSR-IDLE state to the U8-CSR-DEDICATED state when the U8-CSR connection is established and returns to U8-CSR-IDLE state when the U8-CSR connection is released. Upon U8-CSR connection release an indication that no dedicated resources exist is passed to the upper layers.
The MS may also enter U8-CSR-DEDICATED state in 24.008 over PS network mode to from CS Domain mode when Handover to 24.008 over 3GPP PS network is being performed. In the same way, the MS enters CS Domain mode from U8-CSR-DEDICATED when Handover from 24.008 over 3GPP PS network.
The 24.008 over 3GPP PS network supports security mechanisms at different levels and interfaces. It is assumed that the 3GPP PS access is secure enough for the service (using the security mechanism specified for the PS service). Optionally IPsec (IPsec is used by IMS) may be utilized to secure the signaling. Authentication will be done on MM layer, and controlled by the PMSC (normal SIM and ISIM authentication procedures).
In addition, it may be desirable to provide security between the AGW and the PMSC. For example, the AGW resides in the HPLMN and the PMSC resides in the VPLMN in the roaming case and it might be appropriate to provide some low-level security (e.g. IPsec tunnels) for the traffic between the AGW and the PMSC.
At step 715, a determination whether to rove from the first domain mode to a second domain mode is made according to predefined roving criteria. The decision to rove may be made by the following entities: the PMSC, the MS, the Radio Access or the 3GPP PS CN network. The decision to rove may be made by one entity alone or in combination with one or more of the other entities.
In one embodiment, the PMSC determines whether to rove from a first domain mode to a second domain mode. The MS will always be GPRS or PS domain attached. At Routing Area Update (or equivalent other concept for LTE) when the MS is moving between Routing Areas, i.e. not at periodic RA updates, the MS will connect to the supporting PMSC and ask what mode of operation it shall be in using U8-CSR signaling. The PMSC may have a database, or some other means to determine what mode the MS should be in.
In one embodiment, the MS determines whether to rove from a first domain mode to a second domain mode. The MS may have pre-provisioned selection criteria. E.g. it shall always be in 24.008 over 3GPP PS network mode when on LTE or HSPA access. Or, the MS contacts the network (PMSC e.g. or a special database) and downloads Roving criteria, such as certain cells, LAs, RAs or TAs or ranges there of. The Roving criteria will be used when the MS determines which mode to enter, and where to rove in.
In one embodiment, the Radio Access determines whether to rove from a first domain mode to a second domain mode. The Radio Access may indicate to the MS what mode to select, e.g. via parameters in the System Information messages.
In one embodiment, the 3GPP PS CN network determines whether to rove from a first domain mode to a second domain mode. The MS receives responses from the 3GPP PS CN network while performing e.g. Routing Area Updates and PDP Context activations and modifications. These responses can also be used to indicate if the 3GPP PS network operator wishes the MS to enter 24.008 over 3GPP PS network mode.
Re-selection between CS Domain Mode and 24.008 over 3GPP PS network modes will now be described. Re-selection comprises Rove-in (from CS Domain mode to 24.008 over 3GPP PS network mode) and Rove-out (from 24.008 over 3GPP PS network mode to CS Domain mode) procedures.
The Rove-in procedure is applicable when it is determined that the MS shall use the 24.008 over 3GPP PS network service. The access mode in the MS is switched to 24.008 over 3GPP PS network mode. The prerequisites for the Rove-in are the following:
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- The MS is aware of the appropriate supporting PMSC i.e. the MS has performed the discovery procedure; and;
- The MS has performed successful registration towards the PMSC. The registration process is described later in this description.
When all the above prerequisites are filled, the MS may decide to perform Rove-in to the 24.008 over 3GPP PS network mode (i.e. the MS switches the serving RR entity to U8-CSR and the SAP between the MM and the U8-CSR is activated). As part of this, the U8-CSR indicates that CS service is available and passes the relevant NAS-level system information for the CS domain to the NAS-layers (i.e. MM).
After this normal MM operations follow, e.g. if the LAI indicated to the NAS is different from the previous LAI indicated to NAS or if CS service was not previously available, then the NAS-layers in the MS will trigger Location Updating procedures towards the PMSC as following:
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- The MS establishes the U8-CSR signaling connection, with the 24.008 over 3GPP PS network supporting PMSC that approved the MS registration previously.
- The PMSC (or very likely the 8PSC entity of the PMSC) is aware of the cell identity of the current PS cell and either uses that or another cell identity (as returned to the MS as part of registration) when indicating the current cell identity towards the MSC-service entity of the PMSC.
While in 24.008 over 3GPP PS network mode, UTRAN RRC and GERAN-RR entities are detached from the RR-SAP in the MS, as a result the entities do not act on any paging request message for the CS domain in UTRAN or GERAN.
If the 24.008 over 3GPP PS network supporting PMSC rejects the registration, and does not provide redirection to another Serving 24.008 over 3GPP PS network supporting PMSC, the MS shall revert to 3GPP CS access network, and start a re-attempt timer. When the timer has timed out, a new registration is attempted, starting with the Discovery procedure. If the MS can not revert to CS access network the MS is no longer reachable for CS domain services.
The Rove-out procedure is applicable when MS determines that it can not be in the 24.008 over PS network mode, or it needs to detach from the 3GPP PS network.
The MS detaches U8-CSR from the RR-SAP and re-attaches UTRAN RRC or GERAN-RR to RR-SAP and restores normal CS domain UTRAN RRC or GERAN-RR functionality. There after may follow a normal CS domain Location Update if CS service is available after rove-out.
For the following example, it is assumed that the MS has determined that 24.008 over 3GPP PS network mode shall be entered.
1. The MS derives a FQDN based on the cell identifier of the current cell. This FQDN could for example take the following format. As an example, the MS has received the cell identifier of the current cell in e.g. the broadcasted system information in the current cell and it consists of the following information: PLMN-ID is 012-123 (i.e. MCC is 012 and MNC is 123), LAC has value 34567, Cell Identity has value of 4567. In this case the built FQDN could for example be:
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- lac34567.mnc123.mcc012.pub.3gppnetwork.org or
- ci4567.1ac34567.mnc123.mcc012.pub.3gppnetwork.org
Once the FQDN is derived, the MS performs a DNS query (via the IP network) to resolve the FQDN to an IP address.
2. The DNS Server returns a response including the IP Address of the relevant 24.008 over 3GPP PS network supporting PMSC.
Still another possibility for building the FQDN is the following two step approach. The MS will first receive an operator specific string during PS Attachment or PDP Context activation/modification procedures. This operator specific string is valid in the current network until the MS receives another operator string. This string could be e.g. “operatorX.com”. The MS uses that string together with the cell identity of the current cell to build an FQDN for the PMSC. For example, using the example from above where LAC of the current cell has value 34567, then “lac34567.operatorX.com” would be built and used towards the DNS to retrieve the IP address of the PMSC.
In one embodiment, the MS performs registration to the appropriate PMSC. The Registration to the PMSC procedure serves the following functions:
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- Ensures the MS is registered to the appropriate PMSC entity i.e. with use of the redirection process;
- MS informs the PMSC that it is now connected through a 3GPP PS access network and is available at a particular IP address and UDP port. The PMSC maintains the registration context for the purposes of e.g. Paging for mobile-terminated calling; and
- Provides the MS with the NAS system information for the CS domain. This “NAS System Information for CS” is delivered to the MS during the Registration to the PMSC process. This enables the MS to rove-in, and following the Registration procedure trigger NAS procedures with the core network (such as Location Area Update, mobile originated calls, mobile terminated calls, etc.).
The registration is performed as described in the following steps:
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- The MS is aware of the appropriate supporting PMSC i.e. the MS has performed the discovery procedure
- The MS initiates registration to the PMSC and informs the PMSC about the current PS cell identity e.g. LAI and cell identifier. The details of this information may vary depending on the 3GPP PS RAT being used (e.g. there are some differences between cell identities in GERAN and UTRAN). The MS also informs whether CS service is available in the current cell and some other relevant information e.g. the current PS RAT (GPRS/UMTS/HSPA/LTE) and the known capabilities of the current PS RAT.
- The PMSC which accepts the registration and provides the MS with the relevant NAS-level system information for the CS domain (e.g. MSC Release Indicator, Attach/Detach allowed, T3212 timeout value (used for Periodic Location Updates) and whether Call re-establishment is allowed). Note that this NAS-level system information for the CS domain is normally broadcasted in the RAN to the MS. As the MS may now be operating in a PS-only 3GPP access network, the PMSC provides the needed information to the MS as part of a successful registration.
Note: The PMSC may also provide the MS with the Rove-in criteria or reject the registration based on the current 3GPP PS RAT or cell identity (or parts of it) or other information provided by the MS and/or configured in the PMSC. E.g. some LAIs of a specific PS RAT are not to be used for 24.008 over 3GPP PS network mode and the registration is rejected.
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- In addition, the PMSC may provide the MS with the Location Area Indicator (LAI) and Cell Identity to be used as the cell identity for the 24.008 over 3GPP PS network mode. If this information is not provided from the PMSC, then the MS uses the identifiers of the current PS cell as the LAI and CI also for the 24.008 over 3GPP PS network mode.
- The PMSC may also redirect the MS to another PMSC based on the current 3GPP PS RAT or cell identity (or parts of it) or other information provided by the MS and/or configured in the PMSC. The PMSC may also rediret the MS to another PMSC for load-balancing reasons.
1. The MS sends U8-CSR KEEP ALIVE to the 24.008 over 3GPP PS network supporting PMSC. The MS includes TMSI in the message as the identification or if no TMSI is available, then IMSI is used.
2. The PMSC acknowledges the U8-CSR KEEP ALIVE message by sending the U8-CSR KEEP ALIVE ACK message to the MS. This acknowledgement is needed as UDP is used as the underlaying transmission mechanism.
The Deregistration from the PMSC procedure allows the MS to explicitly inform the PMSC that it is leaving the 24.008 over 3GPP PS network mode (e.g. when it is about to enter a network where the normal CS service is available and the MS is not supposed to use 24.008 over 3GPP PS network anymore), by sending a U8-CSR DEREGISTER message to the PMSC, allowing the PMSC to free resources that it assigned to the MS.
The PMSC may also autonomously release the MS registration context, and send a U8-CSR DEREGISTER message to the MS. NOTE: At power-down the U8-CSR sublayer of the MS ensures that the MS explicitly detaches from the network, where possible, before completing the Deregistration from the PMSC procedure.
The MS is authenticated to the 24.008 over 3GPP PS network service using normal MM level Authentication that may take place after the Rove-In procedure if the normal Location Update procedure is triggered.
3GPP PS network encryption will be used. Security may also be provided between the AGW and the PMSC.
The U8-CSR connection is a logical connection between the MS and the 24.008 over 3GPP PS network supporting PMSC. It is established when the upper layers in the MS request U8-CSR to enter dedicated mode. When a successful response is received from the network, U8-CSR replies to the upper layer that it has entered dedicated mode. The upper layers have then the possibility to request transmission of NAS messages to the network.
1. The MS initiates U8-CSR connection establishment by sending the U8-CSR REQUEST message to the 24.008 over 3GPP PS network supporting PMSC. This message contains the Establishment Cause indicating the reason for U8-CSR connection establishment.
2. Depending on the reason for U8-CSR connection establishment, the PMSC may request modification of the signaling bearer from the PCRF to be able to cope with signaling that may follow.
3. Possible response from the PCRF.
4. 24.008 over 3GPP PS network supporting PMSC signals the successful response to the MS by sending the U8-CSR REQUEST ACCEPT and the MS enters dedicated mode and the U8-CSR state changes to U8-CSR-DEDICATED.
5. Alternatively, the 24.008 over 3GPP PS network supporting PMSC may return a U8-CSR REQUEST REJECT indicating the reject cause.
1. The 24.008 over 3GPP PS network supporting PMSC decides to release the signalling and user plane connection resources allocated to the MS (e.g. in Iu interface that could be seen as an Iu Release Command).
2. The 24.008 over 3GPP PS network supporting PMSC commands the MS to release the signalling plane and user plane resources, using the U8-CSR RELEASE message.
3. The MS confirms resource release to the 24.008 over 3GPP PS network supporting PMSC using the U8-CSR RELEASE COMPLETE message and the MS enters idle mode and the U8-CSR state in the MS changes to U8-CSR-IDLE.
4. If resources has been requested in the U8-CSR connection Establishment and/or during the traffic channel assignment, the PMSC will ask for a modification of the signaling bearer from the PCRF. The PMSC may also ask PCRF to release the Secondary PDP context if such was allocated for the user plane. This may be uncorrelated to step 2 and 3.
5. Response from the PCRF.
6. All the signaling and user plane connection resources allocated to the MS are released (e.g. in Iu interface that could be seen as an Iu Release Complete).
1. The 24.008 over 3GPP PS network supporting PMSC sends U8-CSR CIPHERING MODE COMMAND to the MS. This message indicates the integrity protection and encryption settings (i.e., that may be applicable after handover/relocation to CS Domain mode). MS stores the information for possible future use after a handover/relocation to CS Domain mode. The message may also indicate whether the MS shall include IMEISV in the U8-CSR CIPHERING MODE COMPLETE message.
2. The MS then sends U8-CSR CIPHERING MODE COMPLETE message to network and includes the IMEISV, if indicated so in the U8-CSR CIPHERING MODE COMMAND.
CS signaling in U8-CSR-DEDICATED state is shown in
1. The 24.008 over 3GPP PS network supporting PMSC encapsulates a NAS/Layer 3 message within a U8-CSR DL DIRECT TRANSFER message that is sent to the MS.
1. For MS initiated signaling the MS U8-CSR layer receives a request from the NAS layer to transfer an uplink NAS signaling message or SMS message. The MS U8-CSR encapsulates the message within a U8-CSR UL DIRECT TRANSFER message and sends the message to the 24.008 over 3GPP PS network supporting PMSC.
Claims
1. A method of determining a domain mode for a mobile station, wherein the mobile station accesses a Packet Switched Core Network through a Long Term Evolution, LTE, radio access network, and wherein a Packet Mobile Switching Center, PMSC, interfaces the Packet Switched Core Network with a Circuit Switched Core Network, said method comprising the steps of:
- determining a first domain mode; and
- determining whether to rove from the first domain mode to a second domain mode according to predefined roving criteria, said determining step including determining whether a current serving cell, location area, routing area, or traffic area requires a change of domain mode;
- wherein the first domain mode and the second domain mode comprise a Circuit Switched domain mode and a 24.008 over 3GPP Packet Switched network mode.
2. The method of claim 1, wherein the roving determination is made by the PMSC.
3. The method of claim 2, wherein the roving determination is made when the mobile station is moving between Routing Areas.
4. The method of claim 3, wherein the mobile station connects to the PMSC using U8-CSR protocol signaling.
5. The method of claim 4, wherein the mobile station sends periodic U8-CSR KEEP ALIVE messages to the PMSC while the mobile station operates in 24.008 over 3GPP Packet Switched network mode.
6. The method of claim 4, wherein the mobile station connects to the PMSC through the steps of:
- the mobile station sending a U8-CSR REQUEST message to the PMSC with an establishment cause;
- the PMSC requesting a modification of the signaling bearer from a Policy and Charging Rules Function, if required by the establishment cause; and
- the PMSC returning an acceptance to the mobile station.
7. The method of claim 4, further comprising the mobile station releasing the connection to the PMSC through the steps of:
- the PMSC deciding to release the signaling and user plane connection resources allocated to the mobile station;
- the PMSC sending a U8-CSR RELEASE message to the mobile station commanding the mobile station to release the signaling and user plane connection resources;
- the mobile station sending a U8-CSR RELEASE COMPLETE message to the PMSC; and
- the mobile station entering idle mode.
8. The method of claim 7, further comprising the steps of:
- the PMSC requesting a modification of the signaling bearer from a Policy and Charging Rules Function; and
- the PMSC requesting release of a Secondary PDP Context, if allocated for the user plane.
9. The method of claim 4, further comprising the steps of:
- the PMSC sending a U8-CSR CIPHERING MODE COMMAND message to the mobile station indicating integrity protection and encryption settings; and
- the mobile station storing the integrity protection and encryption settings for use if the mobile station roves to the Circuit Switched domain mode.
10. The method of claim 4, wherein the mobile station and the PMSC utilize Circuit Switched signaling in U-B CSR-DEDICATED mode, and the PMSC encapsulates a NAS/Layer 3 message within a U8-CSR DL DIRECT TRANSFER message sent to the mobile station.
11. The method of claim 4, wherein the mobile station and the PMSC utilize Circuit Switched signaling in U-8 CSR-DEDICATED mode, and the mobile station encapsulates a NAS message or SMS message within a U8-CSR UL DIRECT TRANSFER message sent to the PMSC.
12. The method of claim 1, wherein the roving determination is made by the mobile station.
13. The method of claim 12, wherein the mobile station has pre-provisioned selection criteria.
14. The method of claim 12, wherein the mobile station downloads roving criteria.
15. The method of claim 1, wherein a Radio Access type indicates to the mobile station what mode to select.
16. The method of claim 15, wherein the Radio Access type indication is provided using parameters in System Information messages.
17. The method of claim 1, wherein the roving determination is made by the Packet Switched Core Network.
18. The method of claim 17, wherein the roving determination is made by a 3GPP Packet Switched Core Network.
19. A method for providing Packet Mobile Switching Center, PMSC, Discovery for a mobile station, said method comprising the steps of:
- deriving by the mobile station, a Fully Qualified Domain Name, FQDN, based on a cell identifier of a current cell;
- sending the FQDN in a query to a Domain Name System, DNS, server; and
- receiving from the DNS server, an IP address of a PMSC based on the FQDN.
20. The method of claim 19, wherein an operator specific string received by the mobile station and the cell identifier of the current cell are used to derive the FQDN.
Type: Application
Filed: Jan 14, 2008
Publication Date: Mar 4, 2010
Inventors: Magnus Hallenstal (Taby), Jari Tapio Vikberg (Jarna)
Application Number: 12/522,201
International Classification: H04W 40/00 (20090101); H04L 12/66 (20060101);