Voice service in evolved packet system

[0001] This patent is a non-provisional application of the US provisional application. Serial No. 61 / 183,935, filed June 3, 2009, entitled Voice Service in Evolved Packet System Using IP Multimedia Subsystem.

Description field [0002] The application generally refers to a mobile communication system and, more particularly, to the provision of voice services in the evolved packet system.

Background [0003] Recently, voice service indicators have been defined and defined in mobile communication systems of the evolved packet system (EPS) to coordinate the availability of network services and the capabilities of mobile devices. Network service indicators include, for example:

IMS Voice Session indication on PS supported;

Voice Centered or Data Centered indication; and indication of only CS voice or only IMS PS voice or preferred CS voice, secondary IMS voice or preferred IMS voice, secondary CS voice.

[0004] The indication IMS Voice Session on PS supported is provided by the network to the user equipment (UE) (given in the non-access stratum (NAS) register (eg, EPS Connection) or in the update NAS registration). The voice-centered or data-centric indication and the indication of CS voice only, PS IMS voice only, preferred CS voice, secondary IMS voice, or preferred IMS voice, secondary CS voice is available in the UE. An operator can configure the indication only CS voice, only IMS PS voice, preferred CS voice, secondary IMS voice, or preferred IMS voice, secondary CS voice in the UE.

[0005] The T-Mobile document, Voice mode selection for CS Fallback and IMS, May 11, 2009, 3GPP TSG SA WG2 Meeting 73, Tallinn, Estonia, describes how to ensure voice mode selection by the UE. The document indicates that it may be necessary to add a user selection of voice-centric versus data-centric in the UE in order to complete the entire selection procedure.

[0006] The NOKIA SIEMENS NETWORKS et al .: Handling of CS / PS Mode Selection, 3GPP DRAFT; R2-092998 (CSFB MODE), San Francisco, USA; April 28, 2009 summarized the solutions for the CSFB mode selection. This document proposes that you agree to disable the capabilities of the UE or the UE disables the capabilities of the E-UTRAN and summarizes the behavior of the UE in case the solution to disable the capabilities of the UE is accepted.

[0007] The ERICSSON document: CS domain and IM CN Subsystem selection principles, May 15, 2009, 3gPP DRAFT; S2-094178_CR-23221 proposes that the CS domain and the selection principles of the IM CN subsystem be added to 23,221. The principles are divided into when the UE is in limited service mode, configured to prefer the CS domain or configured to prefer IMS for voice services.

Summary [0008] In one aspect of the present description, a procedure is provided in a User Equipment (UE), as detailed in claim 1.

[0009] According to another aspect of the present description, a non-transient computer readable medium is provided as detailed in claim 6.

[0010] According to another aspect of the present description, a User Equipment is provided as detailed in claim 7.

[0011] Advantageous features are described in the dependent claims.

Detailed description

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Abbreviations and terminology

<td colspan="2"> [0012]</td>

<td>ACE</td><td>Access layer</td>

<td>CN</td><td>Core network</td>

<td>CS</td><td>With circuit switching</td>

<td>CSFB</td><td>CS deployment Package System Mobility Management</td>

<td>EMM</td><td>evolved (EPS)</td>

<td>eNB</td><td>eNodeB</td>

<td>EPC</td><td>Package Core Evolved</td>

<td>EPS</td><td>Package System Evolved</td>

<td>E-UTRAN</td><td>UTRAN evolved</td>

<td>IMS</td><td>IP multimedia subsystem</td>

<td>IM CN</td><td>IP Multimedia Central Network</td>

<td>MAC</td><td>Media access control</td>

<td>MS</td><td>Mobile station</td>

<td>NAS</td><td>Non-access stratum</td>

<td>NW</td><td>Net</td>

<td>$</td><td>With packet switching</td>

<td>RA</td><td>Routing area Data convergence protocol by</td>

<td>PDCP</td><td>packages</td>

<td>RAN</td><td>Radio access network</td>

<td>RAU</td><td>Routing Area Update</td>

<td>RB</td><td>Radio carrier</td>

<td>RLC</td><td>Radio link control</td>

<td>RRC</td><td>Control of radio resources</td>

<td>TA</td><td>Tracking area</td>

<td>TAI</td><td>TA identity</td>

<td>TAU</td><td>Update tracking area</td>

<td>TS</td><td>Technical specification</td>

<td>EU</td><td>User equipment Mobile telecommunications system</td>

<td>UMTS</td><td>universal</td>

<td>UTRAN</td><td>UMTS ground RAN</td>

<td>VoIMS</td><td>Voice over IMS</td>

[0013]

In the example implementation described in this application, the voice service indicators may be VoIMS indicators provided by the network, user use settings and voice settings of the user equipment. In the following description, the voice service indicators are called:

a) (provided by the Network) (IMS) The VoIMS indicator indicating the above mentioned IMS Voice Session on PS or the IMS Voice Session on IMS not mentioned above, and indicates whether voice sessions on PS controlled and managed by the IP multimedia subsystem are supported or not;

b) The use configuration of the UE indicating the Voice Centered or Data Centered mentioned above. The usage configuration of the UE is a configuration of the UE indicating whether the UE has a preference for voice services over data services or vice versa. If the UE has a preference for voice services, then the UE usage setting is Voice Centered. If the UE has a preference for data services, then the usage configuration of the UE is Data Centered. For the avoidance of doubt, a UE that is data centric may still require voice services. If a UE only requires data services and can accept that there is no voice service, the UE usage setting is Data only. The two configurations can have the following meanings:

- Voice-centric: a voice-centric UE must be able to use voice services and, therefore, will attempt to obtain voice services regardless of how such services can be provisioned.

ES 2 736 773 T3

- Data-centric: a data-centric UE prefers to have the best possible PS services even if this implies that it is not possible to access voice services.

An additional use configuration of the Data Only UE is possible. In the event that this additional configuration is possible, then the three configurations can have the following meanings:

- Voice-centric: a voice-centric UE must be able to use voice services and, therefore, will attempt to obtain voice services regardless of how such services can be provisioned.

- Data-centric: a data-centric UE prefers to have the best possible PS services (that is, it prefers to remain in the E-UTRAN) as long as access to voice service is not excluded.

- Data only: a data-centric UE prefers to have the best possible PS services even if this implies that it is not possible to access voice services. Y

c) The voice configuration of the UE indicating the indications of CS voice only, PS voice only, PS IMS only voice, preferred CS voice, secondary IMS voice or preferred IMS voice, secondary CS voice mentioned above. The voice configuration of the UE is a configuration of the UE indicating the domain that will be used for voice services.

Table 1 summarizes this grouping and naming convention.

[0014]

Table 1 - Description of voice indicators

<td>Generic indicator name used in this application</td><td>Name of the indicators in the descriptive reports</td><td>Property of the indicators</td>

<td>VoIMS indicator</td><td>-IMS voice session on PS not supported or -IMS voice session on PS supported</td><td>Established by the NW. Provided by the NW to the EU in response to each NAS record (e.g., EPS Connection) or NAS record update.</td>

<td>UE usage settings</td><td>-Focused on voice or Centered on data or Data only</td><td>It could be supplied by the Operator or it could be changed by the UE, for example, as a result of user input.</td>

<td>UE voice settings</td><td>-Only CS voice or -Only IMS PS or -Voz CS voice preferred, secondary IMS voice or preferred IMS voice, secondary CS voice.</td><td>It could be supplied by the Operator or it could be changed by the UE, for example, as a result of user input.</td>

[0015] In an example implementation, a network message may include a VoIMS indicator. For example, the message CONNECTION ACCEPT according to 3GPP standard TS 24.301 can be implemented as shown in table 2 and / or in Iu mode according to 3GPP standard TS 24.008 shown in table 3. The VoIMS indicator can be sent by the network to a UE to indicate voice support through IMS sessions.

Table 2: 3GPP CONNECTION ACCEPTANCE TS 24.301

<td>IEI</td><td>Information element</td><td>Type / Reference</td><td>Presence</td><td>Format</td><td>Length</td>

<td></td><td>Protocol discriminator</td><td>Protocol discriminator 9.2</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Security Header Type</td><td>Type of security header 9.3.1</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Message Identity Connection Acceptance</td><td>Message Type 9.8</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>EPS Connection Result</td><td>EPS Connection Result 9.9.3.10</td><td>M</td><td>V</td><td> 1/2</td>

ES 2 736 773 T3 (continued)

<td></td><td>Leftover semioctet</td><td>Leftover semioctet 9.9.2.9</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>T3412 Value</td><td>GPRS Timer 9.9.3.16</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>TAI List</td><td>Identity list of the tracking area 9.9.3.33</td><td>M</td><td>LV</td><td> 7-97</td>

<td></td><td>ESM message container</td><td>ESM message container 9.9.3.15</td><td>M</td><td>LV-E</td><td>2-n</td>

<td> 50</td><td>GUTI</td><td>Mobile identity EPS 9.9.3.12</td><td>OR</td><td>TLV</td><td> 13</td>

<td> 13</td><td>Location Area Identification</td><td>Identification of the location area 9.9.2.2</td><td>OR</td><td>TV</td><td> 6</td>

<td> 23</td><td>MS identity</td><td>Mobile identity 9.9.2.3</td><td>OR</td><td>TLV</td><td> 7-10</td>

<td> 53</td><td>EMM cause</td><td>Cause EMM 9.9.3.9</td><td>OR</td><td>TV</td><td> 2</td>

<td> 17</td><td>T3402 value</td><td>GPRS Timer 9.9.3.16</td><td>OR</td><td>TV</td><td> 2</td>

<td> 59</td><td>T3423 Value</td><td>GPRS Timer 9.9.3.16</td><td>OR</td><td>TV</td><td> 2</td>

<td>4A</td><td>Equivalent PLMN</td><td>PLMN List 9.9.2.8</td><td>OR</td><td>TLV</td><td> 5-47</td>

<td> 34</td><td>Emergency number list</td><td>List of emergency numbers 9.9.3.37</td><td>OR</td><td>TLV</td><td> 5-50</td>

<td> 39</td><td>VoIMS indicator</td><td>VoIMS 9.9.x indicator</td><td>OR</td><td>TV</td><td> 1</td>

Table 3: 3GPP CONNECTION ACCEPTANCE TS 24.008

<td>IEI</td><td>Information Element</td><td>Type / Reference</td><td>Presence</td><td>Format</td><td>Length</td>

<td></td><td>Protocol discriminator</td><td>Protocol discriminator 10.2</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Jump indicator</td><td>Jump Indicator 10.3.1</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Message Identity Connection Acceptance</td><td>Message Type 10.4</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>Connection result</td><td>Connection result 10.5.5.1</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Force standby</td><td>Force standby 10.5.5.7</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Periodic RA update timer</td><td>GPRS Timer 10.5.7.3</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>Radio Priority for SMS</td><td>Radio priority 10.5.7.2</td><td>M</td><td>V</td><td> 1/2</td>

ES 2 736 773 T3 (continued)

<td></td><td>Radio priority for TOM8</td><td>Radio Priority 2 10.5.7.5</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Routing Area Identification</td><td>Routing area identification 10.5.5.15</td><td>M</td><td>V</td><td> 6</td>

<td> 19</td><td>P-TMSI signature</td><td>P-TMSI signature 10.5.5.8</td><td>OR</td><td>TV</td><td> 4</td>

<td> 17</td><td>Timer value PREPARED negotiated</td><td>GPRS Timer 10.5.7.3</td><td>OR</td><td>TV</td><td> 2</td>

<td> 18</td><td>P-TMSI assigned</td><td>Mobile identity 10.5.1.4</td><td>OR</td><td>TLV</td><td> 7</td>

<td> 23</td><td>MS identity</td><td>Mobile identity 10.5.1.4</td><td>OR</td><td>TLV</td><td> 7-10</td>

<td> 25</td><td>GMM Cause</td><td>Cause of GMM 10.5.5.14</td><td>OR</td><td>TV</td><td> 2</td>

<td>2A</td><td>T3302 value</td><td>GPRS 2 Timer 10.5.7.4</td><td>OR</td><td>TLV</td><td> 3</td>

<td>8C</td><td>Cell notification</td><td>Cell notification 10.5.5.21</td><td>OR</td><td>T</td><td> 1</td>

<td>4A</td><td>Equivalent PLMN</td><td>PLMN List 10.5.1.13</td><td>OR</td><td>TLV</td><td> 5-47</td>

<td>B-</td><td>Network feature support</td><td>Network feature support 10.5.5.23</td><td>OR</td><td>TV</td><td> 1</td>

<td> 34</td><td>Emergency number list</td><td>List of numbers of emergency 10.5.3.13</td><td>OR</td><td>TLV</td><td> 5-50</td>

<td>TO-</td><td>MS information requested</td><td>MS information requested 10.5.5.25</td><td>OR</td><td>TV</td><td> 1</td>

<td> 37</td><td>T3319 Value</td><td>GPRS 2 Timer 10.5.7.4</td><td>OR</td><td>TLV</td><td> 3</td>

<td> 38</td><td>T3323 value</td><td>GPRS 2 Timer 10.5.7.4</td><td>OR</td><td>TLV</td><td> 3</td>

<td> 39</td><td>VoIMS indicator</td><td>VoIMS indicator</td><td>OR</td><td>TV</td><td> 1</td>

[0016] As described in this application, a UE has multiple protocol layers. An example UE, described in this application, includes 3 layers (IMS layer, NAS layer and an AS layer). The ordering of the example is as follows: IMS is above the NAS and AS layers and the AS layer is a lower layer than the NAS and IMS layer. Therefore, the NAS layer and / or the AS layer may be referred to as lower layers from the perspective of the IMS layer. The IMS layer can be called an upper layer.

[0017] In some example implementations, after completion of a connection procedure, for example, in Iu mode, if the VoIMS indicator is available in the CONNECTION ACCEPTANCE message e 10 indicates IMS Voice Session on PS supported the successful completion of the connection procedure to the upper layers will be indicated, for example, for the start of the SIP registration in the IP Multimedia subsystem. In some additional example implementations, the successful completion of the connection procedures is indicated to the upper layer subject to the voice configuration of the UE which is configured, for example, in one of PS Only Voice or Preferred IMS Voice, Secondary CS Voice .

[0018] In another example implementation, a FOLLOW-UP AREA UPDATE message according to 3GPP TS 24.301 can be implemented as shown in table 4.

ES 2 736 773 T3

Figure 4: FOLLOW-UP AREA UPDATE

<td>IEI</td><td>Information element</td><td>Type / Reference</td><td>Presence</td><td>Format</td><td>Length</td>

<td></td><td>Protocol discriminator</td><td>Protocol discriminator 9.2</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Security Header Type</td><td>Type of security header 9.3.1</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Identity of the update acceptance message of the tracking area</td><td>Message Type 9.8</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>EPS update result</td><td>Update result of EPS 9.9.3.13</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Leftover semioctet</td><td>Leftover semioctet 9.9.2.9</td><td>M</td><td>V</td><td> 1/2</td>

<td>5A</td><td>T3412 Value</td><td>GPRS Timer 9.9.3.16</td><td>OR</td><td>TV</td><td> 2</td>

<td> 50</td><td>GUTI</td><td>Mobile identity EPS 9.9.3.12</td><td>OR</td><td>TLV</td><td> 13</td>

<td> 54</td><td>TAI List</td><td>Identity list of the tracking area 9.9.3.33</td><td>OR</td><td>TLV</td><td> 8-98</td>

<td> 57</td><td>EPS carrier context status</td><td>Carrier context status EPS 9.9.2.1</td><td>OR</td><td>TLV</td><td> 4</td>

<td> 13</td><td>Location Area Identification</td><td>Identification of the location area 9.9.2.2</td><td>OR</td><td>TV</td><td> 6</td>

<td> 23</td><td>MS identity</td><td>Mobile identity 9.9.2.3</td><td>OR</td><td>TLV</td><td> 7-10</td>

<td> 53</td><td>EMM cause</td><td>Cause of EMM 9.9.3.9</td><td>OR</td><td>TV</td><td> 2</td>

<td> 17</td><td>T3402 value</td><td>GPRS Timer 9.9.3.16</td><td>OR</td><td>TV</td><td> 2</td>

<td> 59</td><td>T3423 Value</td><td>GPRS Timer 9.9.3.16</td><td>OR</td><td>TV</td><td> 2</td>

<td>4A</td><td>Equivalent PLMN</td><td>PLMN List 9.9.2.8</td><td>OR</td><td>TLV</td><td> 5-47</td>

<td> 8-</td><td>ASME identifier of NAS key set</td><td>NAS key set identifier 9.9.3.21</td><td>OR</td><td>TV</td><td> 1</td>

<td> 34</td><td>Emergency number list</td><td>List of emergency numbers 9.9.3.37</td><td>OR</td><td>TLV</td><td> 5-50</td>

<td> 39</td><td>VoIMS indicator</td><td>VoIMS 9.9.x indicator</td><td>OR</td><td>TV</td><td> 1</td>

[0019] In some example implementations, for example, in Iu mode, after the successful completion of the update procedure of the tracking area, the VoIMS indicator, if received in the message ACCEPTANCE 5 OF UPDATE OF THE FOLLOW-UP AREA, is will indicate to the upper layers.

[0020] A message ACCEPTING UPDATE OF THE ROADING AREA can be sent by the network to the EU to provide the UE with data related to the management of GPRS mobility in response to an UPDATE REQUEST FOR THE ROADING AREA from the EU. The message 10 ACCEPTANCE OF UPDATE OF THE ROADING AREA, if received or provided to the UE, according to,

ES 2 736 773 T3 for example, the 3GPP TS 24.008 standard, may include a VoIMS indicator as shown in table 5.

Table 5: ACCEPTANCE OF UPDATE OF 3GPP ROADING AREA TS 24.008

<td>IEI</td><td>Information Element</td><td>Type / Reference</td><td>Presence</td><td>Format</td><td>Length</td>

<td></td><td>Protocol discriminator</td><td>Protocol discriminator 10.2</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Jump indicator</td><td>Jump Indicator 10.3.1</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Identity of the routing area update acceptance message</td><td>Message Type 10.4</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>Force standby</td><td>Force standby 10.5.5.7</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Update result</td><td>Update Result 10.5.5.17</td><td>M</td><td>V</td><td> 1/2</td>

<td></td><td>Periodic RA update timer</td><td>GPRS Timer 10.5.7.3</td><td>M</td><td>V</td><td> 1</td>

<td></td><td>Routing Area Identification</td><td>Routing area identification 10.5.5.15</td><td>M</td><td>V</td><td> 6</td>

<td> 19</td><td>P-TMSI signature</td><td>P-TMSI signature 10.5.5.8</td><td>OR</td><td>TV</td><td> 4</td>

<td> 18</td><td>P-TMSI assigned</td><td>Mobile identity 10.5.1.4</td><td>OR</td><td>TLV</td><td> 7</td>

<td> 23</td><td>MS identity</td><td>Mobile identity 10.5.1.4</td><td>OR</td><td>TLV</td><td> 7-10</td>

<td> 26</td><td>List of receiving N-PDU numbers</td><td>List of receiving N-PDU numbers 10.5.5.11</td><td>OR</td><td>TLV</td><td> 4-19</td>

<td> 17</td><td>Timer value PREPARED negotiated</td><td>GPRS Timer 10.5.7.3</td><td>OR</td><td>TV</td><td> 2</td>

<td> 25</td><td>GMM Cause</td><td>Cause of GMM 10.5.5.14</td><td>OR</td><td>TV</td><td> 2</td>

<td>2A</td><td>T3302 value</td><td>GPRS 2 Timer 10.5.7.4</td><td>OR</td><td>TLV</td><td> 3</td>

<td>8C</td><td>Cell notification</td><td>Cell notification 10.5.5.21</td><td>OR</td><td>T</td><td> 1</td>

<td>4A</td><td>Equivalent PLMN</td><td>PLMN List 10.5.1.13</td><td>OR</td><td>TLV</td><td> 5-47</td>

<td> 32</td><td>PDP context status</td><td>PDP context status 10.5.7.1</td><td>OR</td><td>TLV</td><td> 4</td>

<td>B-</td><td>Network feature support</td><td>Network feature support 10.5.5.23</td><td>OR</td><td>TV</td><td> 1</td>

<td> 34</td><td>Emergency number list</td><td>List of emergency numbers 10.5.3.13</td><td>OR</td><td>TLV</td><td> 5-50</td>

<td> 35</td><td>MBMS context status</td><td>MBMS context status 10.5.7.6</td><td>OR</td><td>TLV</td><td> 2-18</td>

ES 2 736 773 T3 (continued)

<td>TO-</td><td>MS information requested</td><td>MS information requested 10.5.5.25</td><td>OR</td><td>TV</td><td> 1</td>

<td> 37</td><td>T3319 Value</td><td>GPRS 2 Timer 10.5.7.4</td><td>OR</td><td>TLV</td><td> 3</td>

<td> 38</td><td>T3323 value</td><td>GPRS 2 Timer 10.5.7.4</td><td>OR</td><td>TLV</td><td> 3</td>

<td> 39</td><td>VoIMS indicator</td><td>VoIMS 10.5.x indicator</td><td>OR</td><td>TV</td><td> 1</td>

[0021] For example, in lu mode, the network may include the VoIMS indicator in a message ACCEPTING UPDATE FROM THE RUNNING AREA (or any other message) to indicate voice support through IMS sessions.

[0022] In another example, the procedure for updating the combined routing area is initiated by an MS GPRS operating in the operating modes A or B of MS, if the MS is in GMM-REGISTERED and MM-INACTIVE status, and if the network operates in network I mode of operation and if it is in Iu mode, when the UE receives an indication from the upper layers that the SIP register in the IP multimedia subsystem has failed and is subject to the configuration of EU use be established, for example, in Voice centered.

[0023] In some implementations, after the completion of a connection procedure or a registration update procedure according to, for example, the 3GPP TS 24.008 standard, access to a CN IM may be initiated. For example, access can be initiated according to 3GPP TS 24.229 section 6.2 B.2.2.1. For example, access to the IM Cn can be initiated when the UE is not registered in the IM CN subsystem and the UE usage configuration is not Voice Centered. In another example, access to the IM CN can be initiated when the UE is not already registered in the IM CN subsystem and the voice configuration of the UE is PS voice only or the voice configuration of the UE is Preferred IMS Voice, Secondary CS Voice . In yet another example, an indication of registration failure of the IM CN subsystem can be provided to the lower layers under the following conditions:

if the registration in the IM CN subsystem fails; or if, after repeated failed attempts to register in the IM CN subsystem, the UE reaches a preset number of retries and terminates other attempts; or if, after repeated failed registration attempts, the user aborts other registration attempts in the IM CN subsystem;

if a registration cancellation initiated by the user is made; or if the network explicitly or implicitly cancels the registration of the UE.

[0024] In some implementations, the UE may perform actions after the NAS indication to select specific RATs. In some implementations, when a UE receives a message that includes an information element for the Capacity Update Requirement and an information element is included for the list of system specific capacity update requirements, then for each of the RATs requested in a specific capacity information element of the UE system, if the UE supports the RAT listed, the UE can: If the RAT listed is E-UTRAN and the NAS has not provided an indication to the AS to select GERAN or UTRAN or the RAT listed is not E-UTRAN, include the inter-RAT radio access capabilities for the RAT listed in the IE capability specific to the UE system of the UE_CAPABILITY_REQUESTED variable. In addition, if the RAT listed is GSM and PS Transfer to GRPS is supported, include the IE Radio Access Capability of the MS in the UE_CAPABILITY_REQUESTED variable.

[0025] In some additional implementations, the UE may perform actions after the NAS indication to select specific RATs. In some implementations, when making the cell selection when leaving the RRC_CONNECTED state, in the transition from RRC_CONNECTED to RRC_IDLE as a result of a NAS indication to select GERAN or UTRAN, the UE can make the cell selection in the GERAN and UTRAN RATs and disable cell selection and reselection to E-UTRAN cells. Similarly, if NAS provides an indication to AS to select GERAN or UTRAN while the UE is in RRC_IDLE, the UE will perform the cell selection in the GERAN and UTRAN RATs and enable cell selection and reselection to E-cells. UTRA

[0026] In some additional implementations, when making cell selection upon exiting the RRC_CONNECTED state, in the transition from RRC_CONNECTED to RRC_IDLE as a result of a NAS indication

EN 2 736 773 T3 to select GERAN or UTRAN, the UE will perform the cell selection in the GERAN and UTRAN RATs and disable cell selection and reselection to E-UTRA cells. If NAS provides the AS with an indication to select GERAN or UTRAN while the UE is in RRC_IDLE, the UE will perform the cell selection in the GERAN and UTRAN RATs and disable cell selection and reselection to E-UTRA cells.

[0027] If NAS provides an indication to AS to select GERAN or UTRAN while the UE is in RRC_CONNECTED, the UE can perform the following action after exiting RRC_CONNECTED, with a cause of release from others:

restart MAC;

stop all timers that are running except T320;

release all radio resources, including the release of the RLC entity, the MAC configuration and the associated PDCP entity for all established RBs;

indicate the release of the RRC connection to the upper layers together with the cause of the release;

if the output of RRC_CONNECTED was not activated by the reception of the MobilityFromEUTRACommand message: enter RRC_IDLE by performing cell selection according to the cell selection procedure, defined for the case of leaving RRC_CONNECTED, for example, as specified in the 3GPP standard TS 36,304;

Figures 1A and 1B show respectively Figure A.2.1-1 and Figure A.4-1 of S2-094178 [iii], and illustrate two use case scenarios. The first use case is when the UE voice configuration is set to Preferred IMS Voice, Secondary CS Voice and the second use case is when the UE voice configuration is configured to IMS Voice Only. These figures indicate the required actions of the UE for different combinations of the VoIMS indicator of the network and the usage configuration of the UE.

[0028] Referring first to Figure 1A, the behavior for the voice configuration of the preferred IMS Voice UE, Voice CS secondary begins in block 1A-1, which simply shows that the voice configuration of the UE is configured in preferred IMS voice, secondary CS voice. In block 1A-2, the UE initiates an EPS connection procedure (not combined). In block 1A-3, the UE checks the IMS voice indication supported from the network, which is received as part of the response to the EPS connection procedure. If IMS voice is supported, then in block 1A-4 the UE uses IMS voice. While connected to the system, the UE can perform a tracking area update (TAU) either periodically or when the UE moves to a different tracking area (TA). When the TAU is performed, the UE may receive a new VoIMS indicator, in which case the UE processing returns to block 1A-3 where the VoIMS indicator is checked. If IMS voice is not supported, then in block 1A-5 the UE performs the combined TA / LA update procedure (also called combined TAU) for CSFB as in TS 23.272. If there is success, then in block 1A-6 the UE remains in the E-UTRAN and uses CSFB if ​​it requires voice services. After the successful completion of the follow-up area update procedure, the VoIMS indicator received in the FOLLOW-UP AREA UPDATE ACCEPTANCE message will be indicated to the upper layers. On the other hand, if there is a fault, then in block 1A-7 the UE checks the configuration of use of the UE for the Voice Centered or Data Centered configuration. If the configuration is data-centric, then in block 1A-8 the UE remains in the current RAT (EUTRAN). On the other hand, if the configuration is voice-centered, then in block 1A-9 the UE selects another RAT where it can obtain voice services.

[0029] A combined registration procedure such as a combined connection procedure or a combined tracking area update refers to a single NAS registration procedure that is used to attempt to register both PS and CS services, where the service of CS voice is provided on the E-UTRAN through CS Deployment (CSFB). For example, a UE operating in CS / PS 1 mode or CS / PS 2 mode, in the EMM-REGISTERED state, will initiate the update procedure of the combined tracking area when, for example, the UE receives an indication of the layers above that the SIP registration in the IMS has failed and the configuration of use of the UE is Voice Centered. An example of a combined connection procedure or an update of the combined tracking area can be found in 3GPP TS 24.301.

[0030] The success of a combined registration procedure means that the UE is registered for both PS and CS services. The failure of a combined procedure means that the UE is registered for PS services but not for CS services. For example, such a failure can be indicated to the UE via the network that sends a message of Update acceptance of the tracking area or of Connection acceptance with an indication or a cause value configured in 'CS domain not available' or a value indicating that the PS domain is not available. In addition there may be other failures, such as a failure when the UE is not registered for CS or PS services.

[0031] As a result of a NAS registration procedure or an EPS connection procedure, a UE initiating the procedures is registered in the network. As a result of this NAS registration, the UE and the network obtain

ES 2 736 773 T3 information that allows sending and receiving messages (IP) as part of the non-access stratum protocols. The UE and the network can send and receive these messages (IP). The information obtained in the UE and the network may need updating. The information obtained can be periodically updated (eg, due to the expiration of a timer) or explicitly updated. A NAS record can be a combined or non-combined NAS record, a successful combined NAS record causes a UE to be registered for EPS and non-EPS services.

[0032] As used in this application, EPS services may be GPRS services according to 3GPP TS 24.008. Non-EPS services are services provided by a CS domain. As used in this application, non-EPS services can be non-GPRS services according to 3GPP TS 24.008. A UE that camps in the E-UTRAN can connect to both EPS and non-EPS services. The non-access stratum (NAS) protocols are protocols between the UE and the mobile switching center (MSC) or the GRPS support node (SGSN) in service in the UTRAN that are not terminated in the UTRAN, and the protocols between the EU and the MME that are not terminated in the E-UTRAN.

[0033] In one implementation, a UE initiating a NAS registration procedure (eg, a combined NAS registration) may send at least one of a CONNECTION REQUEST message (for example, a combined CONNECTION REQUEST) or a Request for update of the tracking area (e.g., a Request for update of the combined tracking area). After sending the message, the UE may receive at least one of a CONNECTION ACCEPTANCE message (e.g., a combined CONNECTION ACCEPTANCE) or an Update Request message from the tracking area (e.g., a Request update of the combined tracking area).

[0034] In one implementation, a UE that updates the NAS registration information (eg, the combined NAS registration) may include an update of the routing area information when the non-access stratum protocols are used between the UE and the SGSN or update the tracking area information when using the non-access stratum protocols between the UE and the MME or update the information when using the non-access stratum protocols between the UE and the MSC. A UE that updates the NAS registration information (e.g., the combined NAS registry) can send at least one of a FOLLOW-UP AREA UPDATE (e.g., FOLLOW-UP AREA UPDATE), a AREA UPDATE ROADING (eg, a COMBINED ROADING AREA UPDATE). After sending the message, the UE can receive at least one of a response (ACCEPTANCE) of FOLLOW-UP AREA UPDATE (p. eg, a FOLLOW-UP AREA UPDATE), a response (ACCEPT) of the RUNNING AREA UPDATE (eg, a combined RUNNING AREA UPDATE). After the successful update of the NAS registration information (e.g., combined NAS registration), a UE is registered for EPS and non-EPS services.

[0035] In one implementation, after performing the NAS registration procedure, the UE may request a service from the network. The UE then sends a service request message (eg, an extended service request) to the network. For example, in order to perform CSFB, the UE is registered for EPS services and non-EPS services, and the UE sends an extended service request NAS protocol message. The UE can receive a SERVICE REJECTION message in response.

[0036] For example, in some implementations, when a UE receives an ATTACH ACCEPTANCE message with cause value of EMM # 18 indicative of CS Domain unavailable, the UE can perform the following actions according to 3GPP TS 24.301:

The UE will stop the timer T3410 if it is still running, it will reset the counter of attempts to update the tracking area, it will configure the EPS update status in EU1 UPDATED and it will enter the EMMREGISTERED.SERVICE-NORMAL state.

The UE will configure the update status in U2 NOT UPDATED.

A UE in CS / PS 1 mode of operation can select GERAN or UTRAN radio access technology instead of E-UTRAN for the selected PLMN or the equivalent PLMN.

A UE in CS / PS 2 mode of operation will not attempt a combined connection or update procedure of the tracking area combined with the current PLMN until the shutdown of the UE or the UICC containing the USIM is eliminated.

A UE whose configuration of use of the UE is Data-centric or Data-only will provide a notification to the user or the upper layers that the CS domain is not available.

If the UE usage setting is changed from Data Centered or Data Only to Voice Centered, an indication will be provided to the AS to select GERAN or UTRAN radio access technology instead of E-UTRAN for the selected PLMN or the equivalent PLMN.

EN 2 736 773 T3 [0037] In some implementations, when a NAS provides an indication to an AS to select GERAN or UTRAN while the UE is in RRC_IDLE, the UE may disable cell selection and reselection to E-UTRAN cells. When a NAS provides an indication to an AS to select GERAN or UTRAN while the UE is in RRC_IDLE, the UE can enable cell selection and reselection to E-UTRAN cells.

[0038] In another example, if a service request cannot be accepted by the network, the network will return a SERVICE REJECTION message to the UE that includes an appropriate EMM cause value. Upon receipt of the SERVICE REJECTION message, the UE will stop timer T3417 and take appropriate action. For example, the cause value of EMM can be # 18 (CS domain not available). If the request was related to the CS withdrawal, the US will send an indication to the MM sublayer and will not attempt the CS withdrawal until an update procedure of the combined tracking area has been successfully completed. The UE can then enter the EMM-REGISTERED state. NORMAL-SERVICE. If the usage configuration of the UE is Data-centric or Data-only, the UE will provide a notification to the user or to the upper layers that the CS domain is not available.

[0039] Referring now to Figure 1B, the behavior for the voice configuration of the IMS PS Voice Only UE begins in block 1B-1 which simply shows the UE configured in IMS PS voice only. In block 1B-2, the UE initiates an EPS connection procedure (not combined). In block 1B-3, the UE checks the supported IMS voice indication from the network. If IMS voice is supported, then in block 1B-4, the UE uses IMS voice. While connected to the system, the UE can perform a tracking area update (TAU) either periodically or when the UE moves to a different tracking area. When the TAU is performed, the UE can receive a new VoIMS indicator, in which case the UE processing returns to block 1B-3 where the VoIMS indicator is checked. If IMS voice is not supported, then in block 1B-5, the UE checks the UE usage settings for Voice Centered or Data Centered. If the configuration is data-centric, then in block 1B-6 the UE remains in the current RAT (E-UTRAN). On the other hand, if the configuration is Voice Centered, then in block 1B-7 the UE selects another RAT where it can obtain voice services.

First problem: IMS registration start failure [0040] A first problem with the behavior specified in Figure 1A and Figure 1B mentioned above is that there is no guarantee that the UE will start the IMS registration. More specifically, if the VoIMS indicator indicates IMS voice session over supported PS, then the UE is expected to use IMS voice, but there is no guarantee that the UE will definitely initiate an IMS record when the voice configuration of the UE is set to only IMS PS voice and preferred IMS voice, secondary CS voice. If the VoIMS indicator shows supported IMS voice over PS session, then the UE knows that there is no NAS or AS reason, which would mean that it cannot perform voice services over IMS. However, in order for this to be achieved, the UE must first initiate an IMS registration.

[0041] The reference to an IMS register in an IMS subsystem can generally be understood to refer to any network procedure that obtains the required information in order to be able to send information to, and receive information from the UE using IMS. Therefore, the network has obtained the required information in order to be able to send information to, and receive information from the UE using IMS, or the network does not have the information. A network may not have such information due to a registration failure or because the UE has not been able to register (eg, the UE has not initiated an IMS registration to provide the network with such information). A SIP register for voice services in an IMS subsystem, according to 3GPP TS 24.229 is a specific example.

[0042] When making an IMS registration for voice services, the UE must include an appropriate indicator (s) so that the IMS subsystem knows that it is requesting voice services. If an appropriate indicator is not included or not granted, then a UE that camps in an E-UTRAN cell with IMS capability will not yet receive IMS voice services or IMS voice mobile session terminated requests.

[0043] In some implementations, in order to ensure that the UE reacts correctly and initiates an IMS registration, the UE will behave as follows:

If the UE voice setting = IMS PS O voice only

If the UE voice setting = preferred IMS voice, secondary CS voice

And the VoIMS indicator indicates IMS voice session over supported PS;

THEN the IMS record will be activated with an appropriate indicator (s) requesting voice service support.

[0044] For example, after the successful completion of a connection procedure, if the VoIMS indicator in a CONNECTION ACCEPT message indicates IMS voice session on supported PS and is subject to the

EN 2 736 773 T3 UE voice configuration, the successful completion of the connection procedure will be indicated to the upper layers for the start of the SIP registration in the IMS.

[0045] As indicated above, in some implementations, the IMS register is achieved through a SIP register. Examples of SIP messages are SIP Requests and SIP Responses. Examples of a SIP Request is a SIP INVITATION or a SIP REGISTER. Examples of functional elements of SlP are P-CSCF, S-CSCF, ICSCF, AS, SCC AS, HSS.

[0046] IMS registration can be performed using a SIP Registration request as described in IETF RFC 3261; SIP Registration requests are processed by an IMS functional element as documented in 3GPP TS 23.228 and 3GPP TS 24.229.

[0047] Figure 2A shows a detailed flow chart of an example implementation for the case where the voice configuration of the UE is configured in preferred IMS voice, secondary CS voice. The figure differs from Figure 1A in the inclusion of block 2A-1 that involves trying to register IMS with appropriate indicators for voice services. In case the UE uses IMS voice in block 1A-4 and then performs a TAU, then the UE will check again the VolMS indicator in block 1A-3 and if VolMS is supported, then in block 2A-1 the UE It will only attempt the IMS Registry with appropriate indicators for voice services if it is not already registered in the IMS for voice services.

[0048] Figure 2B shows a detailed flow chart of an example implementation for the case where the voice configuration of the UE is configured in IMS PS voice only. The figure differs from Figure 1B in the inclusion of block 2B-1 which implies trying the IMS register with indicators suitable for voice services. In case the UE uses IMS voice in block 1B-4 and then performs a TAU, then the UE will check again the VolMS indicator in block 1B-3 and if VolMS is supported, then in block 2B-1 the UE It will only attempt the IMS Registry with appropriate indicators for voice services if it is not already registered in the IMS for voice services.

Second problem: The IMS record for voice may fail [0049] A second problem with the behavior described above with reference to Figures 1A and 1B is that there is no guarantee that the IMS record for voice will be successful. More specifically, there is no guarantee that the IMS registration for voice will be successful, just because the EPS connection or the update of the tracking area is successful and the IMS voice support network. An example of a reason that the registration may fail is because the SIP registration does not allow it due to limitations in the user's subscription. Another example of a reason is that the IMS record fails due to deleted messages or a delay in receiving messages. If the IMS registration fails, and the UE does nothing and remains connected to EPS, but not registered in IMS for voice services, then IMS voice sessions (originated in the mobile or terminated in the mobile) cannot be performed. This same situation may exist if the SIP registration was successful; however, the indicator in the voice services request was not allowed (that is, the indicator requested for voice was not returned in the SIP 200 OK response to the SIP registration request). In this case, the UE may register with IMS for the use of some services, but it may not be allowed to use this register to transmit voice media.

Example 1 [0050] In some implementations, the UE is configured to address this problem by recognizing a situation where the IMS register for voice has failed, the voice configuration of the UE is configured in preferred IMS voice, secondary CS voice. After recognizing this situation, the UE is configured to immediately attempt a combined registration procedure. This will then allow the UE to obtain voice services through CSFB if ​​it is supported. If the combined registration procedure fails, then the UE considers the configuration of use of the UE. If the UE usage setting is Voice Centered or Data Centered, then the UE selects another RAT where it can obtain voice services. If the UE usage setting is Data only, then the UE remains in the current RAT (i.e., E-UTRAN) without access to voice services.

[0051] Figure 3A shows a detailed flow chart of an example implementation for this case. The figure differs from Figure 2A in that if the IMS register fails after activation of the IMS register in block 2A-1, as indicated in 30, then the processing continues in block 1A-5 with the performance of a combined registration procedure for CSFB as in TS 23.272. In addition, block 1A-8 (which remains in the current RAT) is performed if the UE is only data (as indicated in 32), and block 1A-9 is performed (the UE selects another RAT) if the UE is voice-centered or data-centric (as indicated in 34).

[0052] Figure 3B shows a detailed flow chart of an example implementation for the case where the voice configuration of the UE is configured in IMS PS voice only. The figure differs from Figure 2B in that if the IMS register fails after activation of the IMS register in block 2B-1, as indicated in 36, then the UE checks the configuration of use of the UE in block 1B- 5. If the UE usage setting is Data only

ES 2 736 773 T3 (as indicated in 38), then the UE remains in the E-UTRAN and will not have access to voice services in block 1B-6. If the UE usage setting is Voice Centered or if the UE usage setting is Focused on data (as indicated in 40), then the UE selects another RAT where it can obtain voice services in block 1B-7 .

Example 2A [0053] In some implementations, the UE is configured to address this problem by recognizing a situation where the IMS register for voice services has failed and the UE usage configuration is Data only. After recognizing this situation, the UE is configured to remain in the EPS where the best PS services can be provided. More specifically, the UE remains in the E-UTRAN (the current RAT in the figures) and does not select another RAT. The best PS services can be provided in the E-UTRAN. PS services can also be provided in GERAN / UTRAN, but they are provided in a less optimized manner in these RATs. The UE does not make a combined registration attempt, but instead, the UE is configured to retry the IMS registration procedure for voice services. It is noted that the UE may have successfully registered with IMS for other services, but it may have been denied access to voice services, as described above, and in this case, the UE retries the IMS registration procedure for services voice. In some implementations, this is a single retry. In other implementations there are multiple retries that, for example, can be executed periodically.

[0054] An example of this behavior is depicted in Figures 4A and 4B. Referring first to Figure 4A, Figure 4A is the same as Figure 2A with the exception of three differences:

the UE performs one or more retries at 50 after the IMS registration has failed;

block 1A-8 is executed after block 1A-7 if the configuration of use of the UE is only data (indicated in 52);

block 1A-9 is executed after block 1A-7 if the configuration of use of the UE is voice-centered or data-centric (indicated in 54).

[0055] Referring now to Figure 4B, Figure 4B is the same as Figure 2B with the exception of three differences:

the UE performs one or more retries at 56 after the IMS registration has failed;

block 1B-6 is executed after block 1B-5 if the configuration of use of the UE is only data (indicated in 58);

block 1B-7 is executed after block 1B-5 if the configuration of use of the UE is voice-centered or data-centric (indicated in 60).

Example 2C [0056] In some implementations, if the combined connection procedure described in example 1 above fails, and the configuration of use of the UE is data only, the UE notifies the user (through the user interface or some other alert) that voice services are not available. For example, if voice services cannot be performed, an indicator may be presented to the user. Any indicator for the user (visualized, auditory, vibrant, are just a few examples) could be used to convey to the user that voice services cannot currently be provided even if the UE is in a coverage area.

[0057] An example of this behavior is represented in Figure 5A which is the same as Figure 2A with the following differences:

after the IMS registration failure at 70 after an IMS registration attempt, the UE performs a combined TAU in block 1A-5;

after block 1A-7, if the configuration of use of the UE is only data (as indicated in 72), the UE notifies the user that voice services are not available in block 5A-1 and the UE remains in the Current RAT;

block 1A-9 follows block 1A-7 if the configuration of use of the UE is voice-centered or data-centric (as indicated in 74).

[0058] Another example of this behavior is represented in Figure 5B which is the same as Figure 2B with the following differences:

After the IMS registration failure at 71 after an IMS registration attempt, the UE checks the User Use Settings

ES 2 736 773 T3

UE for Voice Centered or Data Centered in block 1B-5;

after block 1B-5, if the configuration of use of the UE is data only (as indicated in 73), the UE notifies the user that voice services are not available in block 5B-1 and the UE remains in the Current RAT;

block 1B-7 follows block 1B-5 if the configuration of use of the UE is voice-centered or data-centric (as indicated in 75).

[0059] After receiving notification that voice services are not available, the user may choose to change the usage settings of the UE to Voice Centered or Data Centered. Since the UE has already tried a combined registration procedure and the attempt failed, then changing the configuration of the use of the UE to Voice Centered or Data Centered will cause the UE to select another RAT (such as GERAN / UTRAN) that could provide voice [0060] In some implementations, The notification to the user that voice services are not available also includes a notice asking the user if they would like to change the usage settings of the UE in order to obtain the voice service.

[0061] An example of this behavior is represented in Figure 6A. Figure 6A is the same as Figure 5A with the following differences:

after block 5A-1, if the user accepts only data (indicated in 82), then the UE remains in the current RAT in block 1A-8;

after block 5A-1, if the user changes the usage settings of the UE to voice-centered or data-centric (indicated in 84), then the UE selects another RAT in block 1A-9.

[0062] In some implementations, when the UE usage configuration is changed from data-centric to voice-centric, the UE provides an indication to the AS to select GERAN or UTRAN radio access technology instead of E-UTRAN for the selected PLMN or the equivalent PLMN. For example, such a procedure can be completed after the UE receives the cause value of EMM # 18.

[0063] Another example of this behavior is depicted in Figure 6B. Figure 6B is the same as Figure 5B with the following differences:

after block 5B-1, if the user accepts only data (indicated in 100), then the UE remains in the current RAT in block 1B-6;

after block 5B-1, if the user changes the configuration of use of the UE to voice-centered or data-centric (indicated in 102), then the UE selects another RAT in block 1A-9.

Example 2D [0064] In the case where the voice configuration of the UE is Preferred IMS Voice, Secondary CS Voice and where the use configuration of the UE is set to Data Only, when the IMS register fails after one or more retries and does not a combined registration procedure is automatically attempted, or in the case where the voice configuration of the UE is Voice only IMS PS and the configuration of use of the UE is set to Data only, then the UE is configured to notify the user (through the user interface or some other alert) that voice services are not available. In this case, the user can choose to change the usage settings of the UE to Voice centered or Data centered. This immediately causes the UE to attempt a combined registration procedure (in the case where the voice configuration of the UE is preferred IMS Voice, secondary CS Voice), which, if successful, would allow the UE to remain in the EPS until it is require voice services, and in that case you get voice services through CSFB. In the case where the voice configuration of the UE is IMS PS Voice Only, the user can change the use settings of the UE to Voice Centered or Data Centered, which would cause the UE to re-select another RAT that can Support voice services.

[0065] An example of this behavior is depicted in Figure 7A. Figure 7A differs from Figure 2A in that:

after the IMS registration failure (112), the UE notifies the user that voice services are not available in block 7A-1;

if the user indicates Voice centered or Data centered (116), then the procedure continues in block 1A-5;

ES 2 736 773 T3 if the user indicates Data only, then the IMS record is not retry (114) and then the procedure continues in block 1A-8;

block 1A-9 follows block 1A-7 in case (118) that the UE usage configuration is Voice Centered or Data Centered.

[0066] Another example of this behavior is depicted in Figure 7B. Figure 7B differs from Figure 2B in that:

after the IMS registration failure (122), the UE notifies the user that voice services are not available in block 7B-1;

if the user indicates Voice centered or Data centered (124), then the procedure continues in block 1B-5;

if the user indicates Data only, and the IMS record is not retry (128), then the procedure continues in block 1B-6;

block 1B-9 follows block 1B-5 in case (126) of the UE usage setting being Voice Centered or Data Centered.

Example 2E [0067] As a continuation of the 2D example, in some implementations, the user is told that the IMS record (original or some number of attempts) has failed, and the user could alternatively request IMS record retry for voice, which could cause the UE to leave the UE usage setting set to Data Centered or Voice Centered but restart periodic IMS registration attempts until it succeeds or until a number of attempts have been attempted and have failed. Alternatively, the user could indicate Data Only, in which case the UE would leave the configuration of use of the UE set to Data Centered and the UE will not retry the IMS register (for the purpose of voice services).

[0068] An example of this behavior is depicted in Figure 7C. Figure 7C differs from Figure 7a in that:

After the IMS registration failure (112), the UE notifies the user that Voice Services is not available in block 7A-1 and if the user indicates RESET at 110, then the procedure continues in block 2A-1.

Another example of this behavior is represented in Figure 7D. Figure 7D differs from Figure 7C in that: after the IMS registration failure (122), the UE notifies the user that voice services are not available in block 7B-1, if the user indicates RESET in (120 ), then the procedure continues in block 2A-1.

Example 3A [0069] In some implementations, the UE is configured to recognize a situation where the IMS register has failed and the configuration of use of the UE is Voice Centered. The UE is configured to, after recognizing this situation and regardless of whether the voice configuration of the UE is IMS PS Voice Only or Preferred IMS Voice, Secondary CS Voice, activate the AS to select / reselect another RAT (the target RAT) in which voice services can be performed (for example, GERAN / UTRAN).

[0070] A first example of this behavior is depicted in Figure 8A. Figure 8A differs from Figure 2A as follows:

After the IMS registration failure at 130, the UE checks the configuration of use of the UE for Voice Centered or Data Centered in block 8A-1;

If the configuration is Data centered or Data only as indicated in 132, the procedure continues in block 1A-5;

If the configuration is Voice Centered as indicated in 138, then the procedure continues in block 1A-9 with the selection of another RAT;

block 1A-8 follows block 1A-7 in the case where the configuration of use of the UE is only data (indicated in

ES 2 736 773 T3

134);

block 1A-9 follows block 1A-7 for the case where the configuration of use of the UE is Voice centered or Data centered (indicated in 136).

[0071] A second example of this behavior is depicted in Figure 8B. Figure 8B differs from Figure 2B as follows:

after the IMS registration failure at 140, the UE checks the configuration of use of the UE for Voice Centered or Data Centered in block 8B-1;

If the configuration is Data only as indicated in 142, the procedure continues in block 1B-6;

If the configuration is Voice Centered or Data Centered as indicated in 144, then the procedure continues in block 1B-7 with the selection of another RAT;

block 1B-6 follows block 1B-5 in the case where the configuration of use of the UE is data only (indicated in 146);

block 1B-7 follows block 1B-5 in the case where the configuration of use of the UE is Voice Centered or Data Centered (indicated in 148).

Example 3B [0072] In some implementations, the UE is configured to, following the RAT reselection as described with reference to Example 3A above, retry the IMS record once it is in the target system if it discovers that the target system Can support IMS voice. If this subsequent attempt to register IMS in the target system fails, then in this case the UE can obtain voice services through CS in the target system.

[0073] A first example of this behavior is represented in Figure 9A which is the same as Figure 8A with the addition of blocks 9A-1, 9A-2 and 9A-3. After block 1A-9, the UE retries the IMS register for voice if it discovers that the target system can support IMS voice in block 9A-1. If there is success, then the UE obtains voice services through PS on the target system in block 9A-2. If there is a failure, then the UE obtains voice services through CS in the target system in block 9A-3.

[0074] A second example of this behavior is shown in Figure 9B which is the same as Figure 8b with the addition of blocks 9B-1, 9B-2 and 9B-3. After block 1B-7, the UE retries the IMS register for voice if it discovers that the target system can support IMS voice in block 9B-1. If there is success, then the UE obtains voice services through PS on the target system in block 9B-2. If there is a failure, then the UE obtains voice services through CS in the target system in block 9B-3.

Third problem: The UE may be limited in an inappropriate RAT [0075] A third problem with the behavior specified in Figures 1A and 1B is that the UE may be limited in an inappropriate RAT. More specifically, if the usage configuration of the UE in Figures 1A and 1B is set to Data Centered, this may lead to the UE not obtaining any voice service. If it is considered that Focused on the data in Figures 1A and 1B means that the UE only wants data services (even if that excludes ANY voice service), that is, Data only, then this is not a problem. In the case where it is considered that data-centricity in Figures 1A and 1B means Data-centric as defined earlier in this document, then this behavior is problematic.

[0076] In addition, if the UE remains in the current RAT and does not have access to voice services because the VoIMS indication of the network (in the registered tracking area, since this indication is by tracking area) did not indicate support, but due to mobility, the UE enters a GERAN / UTRAN radio coverage routing area or the E-UTRAN coverage tracking area where the VoIMS indicator of the network indicates that Voice IMS PS is supported, then the UE must subsequently retry the IMS record for voice.

[0077] In another situation, if the voice configuration of the UE is IMS PS Voice Only or Preferred IMS Voice, Secondary CS Voice, and the UE usage configuration is set to Voice Centered or Data Centered, the UE You can end up camping in GERAN / UTRAN and use CS voice services for voice even if voice over IMS services in LTE or GERAN / UTRAN may be available due to the mobility of the UE. As the UE moves, it can enter the coverage area of ​​a new E-UTRAN tracking area or a new GERAN / UTRAN routing area that supports IMS Voice, in which case there is a possibility that the UE can obtain IMS voice services over GERAN / UTRAN or over LTE, and for a data-centric UE better PS service over LTE, if not limited in GERAN / UTRAN.

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Example 1 [0078] In some implementations, the UE is configured to recognize a situation where the configuration of use of the UE is set to Data Only, the voice configuration of the UE is IMS PS Voice Only or Preferred IMS Voice, Secondary CS Voice and in which, when you tried the EPS connection, you discovered that the IMS over PS voice session is not supported, so that the UE ends up camping in E-UTRAN without access to voice services. The support of the IMS voice session over PS is by tracking area (TA). The UE is configured to then monitor the TA of neighboring E-UTRAN cells until a cell with a different TA / RA is detected (or alternatively a cell with a TA outside the UE TAI list). After detecting such an LTE cell, the UE attempts to camp in this cell and sends an Update of the tracking area to the network as part of this procedure. In response to this, the UE receives an update response from the tracking area. The update response of the tracking area includes the VoIMS Network Indicator for this tracking area. If the indicator is IMS Voice Session on PS supported, then the UE retries the IMS register with indicators requesting voice services. The following behavior can be, for example, according to the implementations described above that deal with the IMS registry failure.

[0079] An example of this behavior is depicted in Figure 10A. When the UE reaches block 1A-8, the scenario described above may occur. The procedure continues in block 10A-1 with the UE monitoring the TA of neighboring E-UTRAN cells until a cell with a different TA is detected (or alternatively a cell with a TA outside the UE TAI list). In block 10A-2, after detecting such an LTE cell, the UE attempts to camp in this cell and sends an Update of the tracking area to the network as part of this procedure. In response to this, the UE receives an update response from the tracking area. The update response of the tracking area includes the VoIMS Network Indicator for this tracking area. If the indicator is Supported IMS Voice Session on PS (block 10A-3), then the UE retries the IMS register with indicators requesting voice services in block 10A-4. The following behavior can be, for example, according to the implementations described above that deal with the IMS registry failure. For a voice configuration of the IMS PS only voice UE, steps 10A-1, 10A-2, 10A-3 and 10A-4 would follow block 1B-6 of Figure 2B.

Example 2 [0080] In some implementations, the UE is configured to recognize a situation where the configuration of use of the UE is set to Voice Centered or Data Centered, the voice configuration of the UE is IMS PS Voice Only or Voice Preferred IMS, secondary CS Voice and when you tried the EPS connection, you receive the VoIMS indicator and discover that the IMS voice session on PS is not supported, so that the UE ends up camping in GERAN / UTRAN with voice service but suboptimal data services. In this case, when the UE is in idle mode, the UE is configured to try (once, or multiple times, for example, at regular intervals, or based on a timer) to re-select an E-UTRAN cell deemed appropriate . As described above, this procedure activates a regular update of the tracking area when the voice configuration of the UE is IMS PS Voice Only or a combined update of the tracking area if the voice configuration of the UE is Preferred IMS Voice, CS Voice high school. If the VoIMS Indicator obtained during the TAU or the combined TA / LA Update Procedure indicates that the IMS voice is supported, then the UE will proceed to attempt the IMS registration with indicators requesting voice services. The following behavior can be, for example, according to the implementations described above that deal with the IMS registry failure.

[0081] An example of this behavior for the voice configuration of the IMS PS Voice Only UE is shown in Figure 10B. When the UE reaches block 1B-7, the scenario described above may occur. In this case, when the UE is in idle mode, the UE is configured to try (once, or multiple times, for example, at regular intervals, or based on a timer) to re-select an E-UTRAN cell deemed appropriate in block 10B-1. This procedure activates a regular update of the tracking area when the UE voice setting is IMS PS Voice only or a combined update of the tracking area if the UE voice setting is Preferred IMS Voice, Secondary CS Voice. If the VoIMS Indicator obtained during the TAU or the combined TA / LA Update Procedure indicates that the IMS voice is supported, then the UE will proceed to attempt the IMS registration with indicators requesting voice services in 10B-

two. For a voice configuration of the preferred IMS Voice UE, Secondary CS Voice, steps 10B-1 and 10B-2 would follow block 1A-9 of Figure 2A.

[0082] [Another example is depicted in Figure 10C. When the UE reaches block 1A-9, the scenario described above may occur. The procedure continues in block 10C-1, where the UE determines that the RA of the current cell is different from the previous RA. In block 10C-2, after detecting such a cell, the UE sends an Update of the routing area to the network as part of this procedure. In response to this, the UE receives an update response from the routing area. The Routing Area Update response includes the Network VoIMS Indicator for this routing area. If the indicator is Supported IMS Voice Session on PS (block 10C-3), then the UE retries the IMS register with indicators requesting voice services in block 10C-4. The following behavior can be, for example, according to the implementations described

ES 2 736 773 T3 previously dealing with the IMS registration failure. For a voice configuration of the IMS PS only voice UE, steps 10C-1, 10C-2, 10C-3 and 10C-4 would follow block 1B-6 of Figure 2B.

[0083] In some implementations, the procedure for updating the combined routing area may be initiated by an MS GPRS operating in modes of operation A or B of MS, when the MS is in GMM-REGISTERED and MM-INACTIVE status, when the network operates in network I mode of operation, and when, if in Iu mode, The UE receives an indication from the upper layers that the SIP registration in the IP multimedia subsystem has failed and the configuration of use of the UE is Voice-centered.

[0084] One aspect of the possible examples described for problem 3 is that the UE obtains the VoIMS indicator for the TA or the RA by performing a NAS registration procedure such as an update of the tracking area or an update of the routing area. This registration procedure requires signaling between the UE and the network. For example, a NAS registration response message may be a response to an ePs connection procedure, a FOLLOW-UP AREA UPDATE response, a RUNNING AREA UPDATE response, a CONNECTION ACCEPTANCE response, or a response from ACCEPTANCE OF UPDATE OF THE FOLLOW-UP AREA. In some implementations, the network is configured to broadcast the VoIMS indicator as part of the broadcast system information sent by each cell. As an example of how this VoIMS indicator could be used, it can be considered as a minor variation of the implementation described in Figure 10B. Instead of the UE attempting to re-select an E-UTRAN cell at regular intervals and perform an update of the tracking area to obtain the VoIMS indicator (as shown in Block 10B-1 of Figure 10B), the UE could Try to read the information of the broadcast system of an E-UTRAN cell at regular intervals to obtain the VoIMS indicator. If the broadcast system information obtained from the VoIMS indicator indicates that the IMS voice is supported, then the UE proceeds to attempt the IMS registration with indicators requesting voice services in 10B-2

Fourth problem: Switch back to Voice centered or Data centered after the UE usage setting has been changed to Data only [0085] A fourth problem with the behavior specified in Figures 1A and 1B mentioned above is that in some situations it is desirable that the usage settings of the UE be changed. For example, if the UE is downloading a large volume of data, then it may be desirable that the UE usage setting is Data only so that the UE uses E-UTRAN even if voice services are not available in EUTRAN. When the download of the large volume of data is completed, then it may be desirable that the configuration of use of the UE be Voice Centered or Data Centered again in order to ensure that the voice is available, even means that it is selected another RAT. A particular problem is that the user can configure the usage settings of the UE to be data only, but then forget to revert the settings back to Voice centered or Data centered at a later stage.

Example 1 [0086] More specifically, if the UE usage configuration in Figures 1A or 1B mentioned above is set to Data Centered, based on user preferences or based on the requirements of applications running on the UE, the configuration of use of the UE can be modified to Data Only to give priority to data services and, therefore, make the UE select the best RAT for data services (i.e., E-UTRAN). However, it is desirable that the configuration of use of the UE can be subsequently modified to the original value (ie, Voice Centered or Data Centered). As an example, the configuration of the use of the UE can be changed by the user at a later time. In another example, an application that runs in the UE and requires the best available PS service even when the UE is Voice Centered or Data Centered, and based on this, the application or the user changes the usage settings of the UE to Data only. However, once the application has finished, the application or the UE changes the usage settings of the UE back to the original value, that is Voice centered or Data centered.

[0087] In such scenarios, once the UE usage configuration is changed to Data Only, the UE will end up selecting the RAT based on the behavior described in the previous implementations for a Data Only UE. However, once the UE usage configuration is changed back to the original value, the UE should try to connect to the appropriate RAT and try to access voice services based on the availability of IMS and the voice settings of the UE of the EU. However, with the current behavior defined for the UE, the UE would not attempt to re-select a suitable RAT or register for the IMS when the IMS is available.

[0088] In certain scenarios, the configuration of use of the UE is modified by the user or an application (or set of applications) running in the UE from Centered on data or Centered on voice to Data only to allow the best PS service for applications running in the UE. Subsequently, the UE usage configuration is reverted to the original configuration based on a set of possible activation conditions. As a result, the UE based on the UE voice configuration performs one or more of the procedures described in the previous implementations to discover if the IMS voice is available, register with the IMS and select

ES 2 736 773 T3 the appropriate RAT.

[0089] With reference to Figure 11A, in one implementation, an application (or set of applications) running in the UE modifies the configuration of use of the UE in block 11A-1. In block 11A-2, the application (s) that modified the usage configuration of the UE terminates (or alternatively, the need for the operation application (s) in data-only mode ends) and causes UE usage settings are restored to the original value. If the voice configuration of the UE is preferred IMS Voice, secondary CS Voice, the UE will behave as in the previous implementations for a UE whose voice configuration of the UE is Preferred IMS Voice, Secondary CS Voice. If the voice configuration of the UE is Voice only IMS PS, the UE will behave as in the previous implementations for a UE whose voice configuration of the UE is Voice only IMS PS. This is generally indicated in block 11A-3.

[0090] With reference to Figure 11B, in one implementation, the user requests a call originating from a mobile in block 11B-1. At the request of the voice call originated in a mobile, the UE returns to Voice centered or Data centered in order to establish the voice call in block 11B-2. The UE then behaves as in the implementation of Figure 11A depending on the voice configuration of the UE. This involves returning to the original UE usage configuration in block 11B-3, and then continuing with one of the procedures described above (11B-4).

[0091] With reference to Figure 11C, in one implementation, the UE receives an email with a voicemail attached in block 11 C-1. Upon request of this email, the UE returns to Voice Centered or Data Centered in order to be able to return the missed call in block 11C-2. The UE then behaves as in the implementation of Figure 11A depending on the voice configuration of the UE. This involves returning to the original UE usage configuration in block 11 C-3, and then continuing with one of the procedures described above (11C-4).

[0092] With reference to Figure 11D, in one implementation, the user receives an SMS indication that a voicemail is waiting or that a call has been lost in block 11D-1. Upon receiving this SMS, the UE returns to Voice Centered or Data Centered in order to establish a voice call to retrieve voicemail and / or return the missed call. The UE then behaves as in the implementation of Figure 11A depending on the voice configuration of the UE. This involves returning to the original UE usage configuration in block 11D-3, and then continuing with one of the procedures described above (11D-4).

[0093] With reference to Figure 11E, in one implementation, an incoming IMS voice call was received by the IMS infrastructure, but the voice call could not be delivered to the UE because the IMS record for IMS voice was unsuccessful, and The UE receives a notification from the IMS of such a missed call in block 11E-1. Upon receiving this notification, the UE returns to Voice Centered or Data Centered in order to be able to return the lost voice call in block 11E-2. The UE then behaves as in the implementation of Figure 11A depending on the voice configuration of the UE. This involves returning to the original UE usage configuration in block 11E-3, and then continuing with one of the procedures described above (11E-4).

[0094] In all previous implementations, recovery can be achieved as an example by storing the value of the original UE usage configuration when it is modified by the application or the user and retrieving the value.

Another mobile device [0095] Referring now to Figure 12, a block diagram of a mobile communication device 700 is shown which can implement procedures related to the UE described in this application. It is to be understood that the mobile device 700 is shown in very specific details by way of example only.

[0096] A processing device (a microprocessor 728) is shown schematically as coupled between a keyboard 714 and a screen 726. The microprocessor 728 controls the operation of the screen 726, as well as the general operation of the mobile device 700, in response to the operation of the keys on the keyboard 714 by a user.

[0097] The mobile device 700 has a housing that can be elongated vertically, or can take other sizes and shapes (including shell-like shell structures). The keyboard 714 may include a mode selection key, or other hardware or software to switch between text input and telephone input.

[0098] In addition to microprocessor 728, other parts of the mobile device 700 are shown schematically. These include: a communications subsystem 770; a short range communications subsystem 702; the keyboard 714 and the screen 726, together with other input / output (I / O) devices including a set of LED 704, a set of I / O devices 706, a serial port 708, a speaker 711 and a microphone 712 ; as well as memory devices including a flash memory 716 and a random access memory (RAM) 718; and various other subsystems of 720 devices. The mobile device 700 may have a 721 battery to power the

EN 2 736 773 T3 active elements of the mobile device 700. The mobile device 700, in some implementations, is a two-way radio frequency (RF) communication device that has voice and data communication capabilities. In addition, in some implementations, the mobile device 700 has the ability to communicate with other computer systems via the Internet.

[0099] The operating system software executed by microprocessor 728, in some implementations, is stored in a persistent storage device, such as flash memory 716, but can be stored in other types of memory devices, such as memory memory. read only (ROM) or similar storage item. In addition, the system software, specific device applications or parts thereof may be temporarily loaded into a volatile storage device, such as RAM 718. In some implementations, one or more parameters representative of the signal constellation inequality They are stored in non-volatile memory or in a volatile storage device. Communication signals received by mobile device 700 can also be stored in RAM 718.

[0100] The microprocessor 728, in addition to its operating system functions, allows the execution of software applications on the mobile device 700. A predetermined set of software applications that control the basic operations of the device, such as a communications module of Voice 730A and a data communication module 730B, can be installed on the mobile device 700 during manufacturing. In addition, a 730C personal information manager (PIM) application module can also be installed on the mobile device 700 during manufacturing. The PIM application, in some implementations, is able to organize and manage data items, such as email, calendar events, voicemail, appointments and task items. The PIM application, in some implementations, is also capable of sending and receiving data elements through a 710 wireless network. In some implementations, the data elements managed by the PIM application are integrated, synchronized and updated seamlessly through of the wireless network 710 with the corresponding data elements of the device user stored or associated with a central computer system. Also, additional software modules, illustrated as another 730N software module, can be installed during manufacturing.

[0101] Communication functions, including data and voice communications, are performed through the communication subsystem 770, and possibly through the short-range communications subsystem 702. The communication subsystem 770 includes a receiver 750, a transmitter 752 and one or more antennas, illustrated as a reception antenna 754 and a transmission antenna 756. In addition, the communication subsystem 770 also includes a processing module, such as a digital signal processor (DSP) 758 and local oscillators (LO) 760. The specific design and implementation of the communication subsystem 770 depends on the communication network where the mobile device 700 is intended to operate. For example, the communication subsystem 770 of the mobile device 700 may be designed to operate with the Mobitex ™, DataTAC ™ mobile data communication networks or the General Packet Radio Service (GPRS) and also designed to operate with any of a variety of voice communication networks, such as the Advanced Mobile Telephone Service (AMPS), Multiple Time Division Access (TDMA), Multiple Code Division Access (CDMA), Personal communications service (PCS), Global system for mobile communications (GSM), etc. Other types of data and voice networks, both separate and integrated, can also be used with the mobile device 700. The particular devices considered herein are multimode mobile devices, and as such include hardware and / or software to implement at least two RATs . More specifically, in a particular example, there would be a respective communication subsystem 770 for each RAT implemented by the device.

[0102] Network access may vary depending on the type of communication system. For example, in Mobitex ™ and DataTAC ™ networks, mobile devices register on the network using a unique personal identification number (PIN) associated with each device. However, in GPRS networks, access to the network is normally associated with a subscriber or user of a device. Therefore, a GPRS device typically has a subscriber identity module, commonly referred to as a subscriber identity module (SIM) card, in order to operate in a GPRS network.

[0103] When the registration or activation procedures of the network have been completed, the mobile device 700 can send and receive communication signals through the communication network 710. The signals received from the communication network 710 by the communication antenna Receive 754 are routed to receiver 750, which provides signal amplification, frequency down conversion, filtering, channel selection, etc., and can also provide analog to digital conversion. The analog to digital conversion of the received signal allows the DSP 758 to perform more complex communication functions, such as demodulation and decoding. Similarly, the signals to be transmitted to the network 710 are processed (for example, modulated and encoded) by the DSP 758 and then provided to the transmitter 752 for digital to analog conversion, up frequency conversion, filtering, amplification and transmission to the communication network 710 (or networks) through the transmission antenna 756.

[0104] In addition to processing communication signals, DSP 758 provides control of receiver 750 and transmitter 752. For example, the gains applied to communication signals in receiver 750 and transmitter

ES 2 736 773 T3

752 they can be adaptively controlled through automatic gain control algorithms implemented in the DSP 758.

[0105] In a data communication mode, a received signal, such as a text message or a download from a web page, is processed by the communication subsystem 770 and is introduced into the microprocessor 728. The received signal is processed. then again by microprocessor 728 for an output to screen 726, or alternatively to some other auxiliary I / O device 706. A user of the device can also compose data elements, such as email messages, using the keyboard 714 and / or some other auxiliary I / O device 706, such as a touch panel, a rocker switch, a control wheel or Other type of input device. The composite data elements can then be transmitted through the communication network 710 through the communication subsystem 770.

[0106] In a voice communication mode, the overall operation of the device is substantially similar to the data communication mode, except that the received signals are sent to a speaker 711, and the signals for transmission are generated by a microphone 712 On the mobile device 700, alternative voice or audio I / O subsystems, such as a voice message recording subsystem, can also be implemented. In addition, the screen 716 can also be used in voice communication mode, for example, to show the identity of a calling party, the duration of a voice call or other information related to the voice call.

[0107] The short-range communications subsystem 702 allows communication between the mobile device 700 and other nearby systems or devices, which do not necessarily have to be similar devices. For example, the short-range communications subsystem may include an infrared device and associated circuits and components, or a Bluetooth ™ communication module to provide communication with systems and devices with similar capabilities.

[0108] Numerous modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that, within the scope of the appended claims, the invention can be practiced differently than specifically described in this application.

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