Communication devices and methods for handling communication in emergency situation

Abstract

Communication devices (140, 110) and methods therein for handling communication in emergency situation are provided A PSAP communication device (140) receives a message or a call request from a user communication 5 device (110) via a communication network node (121). The PSAP communication device (140) sends a request to the user communication device (110). The request comprises an indication indicating that the request is a silent call or silent message request to the user communication device (110) without causing any audible sound on the user communication device (110). The PSAP communication device 10 (140) receives a first response from the user communication device (110) indicating that the request is being processed by the user communication device (110) and receives a second response from the user communication device (110) indicating that a communication channel has been established between the PSAP and user communication devices. The PSAP communication device (140) then 15 receives audio and / or video stream captured by the user communication device (110).

Description

[0001] COMMUNICATION DEVICES AND METHODS FOR HANDLING

[0002] COMMUNICATION IN EMERGENCY SITUATION

[0003] TECHNICAL FIELD

[0004] Embodiments herein relate to handling communication between communication devices in a wireless communication network. In particular, embodiments herein relate to handling communication between a communication device of a Public-Safety Answering Point (PSAP) and a user communication device in emergency situation.

[0005] BACKGROUND

[0006] The 3rd Generation Partnership Project (3GPP) standards are currently working on a Short Message Service (SMS) over Internet Protocol Multimedia Subsystem (IMS) emergency service. IMS is a standardized architecture for delivering multimedia services over Internet Protocol (IP) networks, including voice, video, and text. The SMS over IMS emergency service is designed to facilitate emergency communication for mobile users and ensures that users can quickly and accurately connect with emergency services when needed, regardless of their location or the presence of a Subscriber Identity Module (SIM) card. This emergency service allows users to send SMS text messages, e.g. an SoS message / SMS, to a first responder person or an emergency service center such as a Public Safety Answering / Access Point (PSAP). The PSAP is a type of call center where the public's telephone calls for first responders such as police, fire department, or emergency medical services / ambulance are received and handled. The purpose of SMS over IMS emergency service is to enable individuals to reach out for help in situations where making a voice call might not be possible or safe, such as in cases of domestic violence, hostage situations, or when a person is unable to speak. However, there is still no technical solution to achieve this.

[0007] A problem with the current direction of the 3GPP work is that the PSAP can send an SMS back to the SoS SMS sender. However the SMS sent back from the PSAP to the SoS SMS sender may cause sound which may put the SoS SMS sender in danger. Further, there is no method whereby the PSAP can make a discreet communication contact with the SoS SMS sender to get more information from the local scene circumstances of the SoS SMS sender. SUMMARY

[0008] Therefore it is an object of embodiments herein to provide a method for handling communication between a PSAP and a user in emergency situation to get more information from the local scene circumstances of the user without causing any danger to the user.

[0009] This disclosure proposes a method whereby a PSAP having received an SoS SMS from a user, can make a call back or send an SMS to the user / sender where the sender’s device, e.g. a smartphone, does not ring or make any audible sound when answered. Then the PSAP can get audio from the sender’s device microphone and maybe video from the sender’s device camera. In this way, the PSAP can get a better understanding of the local scene circumstances of the user / sender without cause any danger to the user / sender.

[0010] According to one aspect of embodiments herein, the object is achieved by a PSAP communication device and method therein for handling communication between the PSAP communication device and a user communication device via a communication network node in a communication network. The PSAP communication device receives a message or a call request from the user communication device via the communication network node. The PSAP communication device sends a request to the user communication device via the communication network node. The request comprises an indication indicating that the request is a silent call or message request to the user communication device without causing any audible sound on the user communication device. The PSAP communication device receives a first response from the user communication device via the communication network node indicating that the request is being processed by the user communication device. The PSAP communication device further receives a second response from the user communication device via the communication network node indicting that a communication channel has been established between the PSAP communication device and the user communication device. The PSAP communication device then receives audio and / or video stream captured by the user communication device.

[0011] According to one aspect of embodiments herein, the object is achieved by a user communication device and method therein for handling communication between the user communication device and a public-safety answering point (PSAP) communication device in a communication network. The user communication device is configured with silent call capability, i.e. the user communication device has the capability of understanding that a request received from the PSAP communication device is a silent call and can supress any audible signal caused by the call. The user communication device sends a message or a call request to the PSAP communication device via a communication network node and receives a request from the PSAP communication device via the communication network node. The request comprises an indication indicating that the request is a silent call or message request to the user communication device. If the received request is a silent call request, the user communication device sends a first response to the PSAP communication device via the communication network node indicating that the request is being processed or to a SMS-centre If the received request is a silent message request. The user communication device processes the request and takes actions based on the indication to supress any audible sound caused by the call or message. If the received request is a silent call request, the user communication device then sends a second response to the PSAP communication device via the communication network node in response to an accept action made by the user of the user communication device indicating that a communication channel has been established between the user communication device and PSAP communication device via the communication network node. The user communication device then sends audio and / or video stream captured by the user communication device to the PSAP communication device via the communication network node.

[0012] Embodiments herein provide a method for handling communication between the PSAP communication device and a user communication device in emergency situation. When an emergency center, e.g. the PSAP, receives an SoS SMS or call from a user, the emergency center can make a call or send an SMS back to the user without causing a ringing signal or any audible sound at the called communication device. The user communication device captures any sound and / or video from the microphone and camera of the user communication device once the user answers the call or SMS. In this way, the emergency center can get better understanding of the situation and provide better emergency help. This may also save lives as a call or message back to a user with a phone that rings, would put the user in great danger at occasions of for example school, or warehouse shootings. Therefore, embodiments herein provide an improved method for handling communication between a PSAP and a user in emergency situation to get more information from the local scene circumstances of the user without causing any danger to the user.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Examples of embodiments herein are described in more detail with reference to attached drawings in which:

[0015] Figure 1 is a schematic block diagram depicting an example of a communication network;

[0016] Figure 2 is a signal flow chart depicting signals for handling communication between a PSAP and a user in an emergency situation;

[0017] Figure 3 is a signal flowchart depicting signals between a communication device and a communication network node;

[0018] Figure 4 is a flowchart illustrating a method performed in a PSAP communication device according to an embodiment herein;

[0019] Figure 5 is a flowchart illustrating a method performed in a user communication device according to an embodiment herein;

[0020] Figure 6 is a schematic block diagram illustrating one embodiment of a PSAP communication device;

[0021] Figure 7 is a schematic block diagram illustrating one embodiment of a user communication device.

[0022] DETAILED DESCRIPTION

[0023] Figure 1 is a schematic block diagram showing an example of a communication network 100 in which embodiments here may be implemented. The communication network 100 comprises a number of end-user devices, e.g. user communication device or user equipment (UE) 110, 111 , used by individuals to access communication services. The communication devices 110, 111 are connected through access networks, e.g. radio access network RAN 120 to an IMS framework 130 for multimedia communication services. The access networks include technologies like cellular networks, Wi-Fi, wired internet connections, or satellite links etc., that provide connectivity to end-user devices. In wireless networks like cellular networks RAN 120, access points 121, 122 referred as communication network nodes, base stations etc., provide radio coverage over a geographical area, i.e. a service area or service cell 12. Mobile network operators (MNOs) operate cellular networks and offer various mobile telecommunication services, including voice calls, text messaging (SMS), multimedia messaging (MMS), and mobile internet access. One or more PSAPs with communication devices 140, 141 serve as emergency call centers for receiving emergency calls, gathering essential information from callers including the nature of the emergency, location, and any additional details needed to assess the situation, and dispatching appropriate services to the location of the emergency based on the information provided by the caller. A PSAP may also be refereed as a first responder person. The communication network 100 may comprise a SMS Center, SMS-C 150 which is a crucial component of a mobile network infrastructure responsible for handling the storage, routing, and delivery of SMS messages. The communication network 100 may further comprise other nodes or function units necessary for its operation which are not shown here.

[0024] The communication network node 121 , 122 may be a transmission and reception point e.g. a Wireless Local Area Network (WLAN) access point or an Access Point Station (AP STA), an access controller, a base station, a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a transmission arrangement of a radio base station, a stand-alone access point or any other network unit capable of communicating with a wireless device within the service area served by the network node 121 , 122 depending e.g. on the radio access technology and terminology used.

[0025] It should be understood by the skilled in the art that “communication device” is a non-limiting term which means any terminal, wireless communication terminal, user equipment, Machine Type Communication (MTC) device, Device to Device (D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablets or even a small base station communicating within a cell.

[0026] The terms “communication device”, “user communication device”, “wireless device”, “UE”, “user equipment”, “terminal equipment”, “wireless terminal” and “terminal” may be used interchangeable herein.

[0027] A network node may be any of gNB, eNB, en-gNB, ng-eNB, gNB Central Unit (gNB- CU), gNB-CU-Control Plane (gNB-CU-CP), gNB-CU-User Plane (gNB-CU-UP), eNB Central Unit (eNB-CU), eNB-CU-Control Plane (eNB-CU-CP), eNB-CU-User Plane (eNB- CU-UP), Integrated Access and Backhaul (lAB)-node, lAB-donor Distributed Unit (IAB- donor DU), lAB-donor-CU, IAB-DU, IAB Mobile Termination (IAB-MT), Open RAN Central Unit (O-CU), O-CU-CP, O-CU-UP, O-DU, O-RAN Radio Unit (O-RU), O-eNB, a Non-Real Time RAN Intelligent Controller (Non-RT RIC), a Real-Time RAN Intelligent Controller (RT-RIC), Vehicle Mounted Relay, a Cloud-based network function, etc.

[0028] The terms “communication network node”, “network node”, “RAN node”, “radio network node”, “gNB” may be used interchangeable herein.

[0029] The terms “PSAP”, “emergency center”, “the first responder person” may be used interchangeable herein.

[0030] According to embodiments herein, when a user served by an MNO sends an SoS SMS or makes a SoS call to a PSAP, the PSAP communication device receives an SoS SMS or call request from the user comunication device, referred as the called UE or UE hereafter. The PSAP can re-use the calling usernumber, typically a Mobile Station International Subscriber Directory Number (MSISDN) of that SMS / call, to establish a silent call or / and message back to the sender / caller. Such silent call / message requires an IMS Network-to-Network Interface (NNI) between the PSAP and the MNO. The IMS- NNI is the interface between two separate IP Multimedia Subsystems (IMS) operated by different service providers or network operators. This interface provides a way for different IMS networks to interconnect, enabling end-to-end service delivery across multiple networks. When communication occurs between users on different IMS networks, such as making a voice call or sending a message, the IMS-NNI facilitates the exchange of signaling and traffic between the two networks.

[0031] The silent call may be established by a Session Initiation Protocol (SIP) Session. SIP is a signaling protocol that is used to initiate, modify, and terminate a session between two or more devices or users on an IP network. It is vital that the initial SIP request of the silent call e.g., SIP INVITE message, includes a silent call indication to the called UE for the UE to not make any noise such by a ringing signal. As an example, this indication may be made by means of a new silent-call media feature tag in the Accept- Contact header.

[0032] Furthermore, this new tag should be augmented by one or more explicit and require parameters. Reason for this is to secure that the operator’s IMS network only forks the initial SIP request / SIP INVITE, to devices that has the silent call capability. Devices with this capability can suppress a ringing signal hence avoid the risk that the called subscriber has a secondary device which is not silent call capable on the same subscriber number, that would cause a ringing signal if receiving the silent call SIP INVITE. As an option, the SIP INVITE can contain a receive-only audio direction in an Session Description Protocol (SDP) offer which defines a mechanism for two entities to establish a common view of a multimedia session. This is to avoid the risk that any e.g., PSAP office background noise, reaches the called subscriber’s smartphone speaker and gets audible, which could put the called subscriber in great danger.

[0033] When the called subscriber views the incoming call notification as a silent call displayed on the call user interface (Ul), the called UE may provide the usual reject or accept buttons. If the user accepts the call, the audio sound captured by the microphone, will be sent uplink i.e., towards the calling PSAP agent via the mobile network, who is able to listen to it.

[0034] After the silent call has been answered, the PSAP agent may want to put questions to the end-user by text but want the end-user to answer in text or chat for the sake of keeping silence. That is the PSAP agent may want to add a chat channel with the called subscriber to exchange messages. Messages maybe sent according to the Message Session Relay Protocol (MSRP), defined in Internet Engineering Task Force (IETF) RFC 4975, technology within the SIP dialogue of the silent call. To enable text in this way, the PSAP communication device may set an SDP offer that contains two media indications, one audio and one MSRP in the initial INVITE SDP offer, and the UE may return an SDP answer that includes both media indications with valid transport IP addresses and ports. The SDP answer is a way for the UE to e.g., inform the network at which IP address and port the UE is ready to receive the media e.g., voice and / or MSRP, that the PSAP is about to send, and also in which directions.

[0035] The PSAP may also add a chat channel with the called subscriber to exchange messages by issuing a re-INVITE or SIP UPDATE during the silent call, for adding a secondary chat media e.g., in the form of MSRP IETF RFC 4975 based text media. In this way the PSAP agent can put questions to the called subscriber by text and get a user response back by text. This chat channel can be made as silent message without causing any audible sound.

[0036] The silent message may be established as a mobile terminating SMS constructed by the PSAP communication device. The protocol identifier (PID) of an SMS may have a new value for indicating “Silent message” to the UE. The UE shall interpret this new value as a request by the sender PSAP, to supress any audible signal and just display the message content set by PSAP e.g. 'How many shooters are there?' etc. In the PID of an SMS, there are reserved bits which are idle and can be used for “silent message” indication, see 3GPP TS 23.040 §9.2.3.9. Figure 2 shows a signal flow chart for handling communication between a PSAP and UE in an emergency situation according to an example embodiment herein.

[0037] As shown in Figure 2, a user in danger makes a call or sends an SMS, e.g. by SMS over non-access stratum (SMSoNAS) or SMSolP, with embedded text, to the PSAP. The SMS may for example reach the PSAP via a SMS Center (SMS-C).

[0038] If the PSAP agent decides to make a silent call or SMS to the user across the IMS NNI with the MNO of the SMS sender, the PSAP communication device sends a SIP INVITE including an Accept-Contact (AC) header set with a silent-call / SMS media feature tag, i.e. AC: Silent call / SMS, along with one or more explicit and require parameters set to e.g. audio only i.e. m=audio, in receive-only direction i.e. a=revonly, over an IMS NNI to the MNO mobile Network (NW). That is a request, SIP INVITE (AC: Silent call / SMS), SDP offer m=audio, a=revonly, is sent to a network node e.g. the network node 121 .

[0039] When the mobile NW has discovered any of the called subscribers device / s that is / are IMS registered and furthermore has / have IMS registered silent call / message capability, the NW forwards the INVITE to that or those devices, only. If the NW does not find any of the called subscriber’s devices to be IMS registered e.g., due to being located under a 2G / 3G radio access or are being IMS registered albeit where the registration lacked a silent-call / message capability, the NW rejects the silent call / message.

[0040] When the SIP INVITE with the SDP parameters set to audio only, in receive-only direction, i.e. SIP INVITE (AC: Silent call / SMS), SDP offer m=audio, a=revonly, reaches a UE with silent call / message capability, the UE sends a response, e.g. a SIP183 response including an SDP potion, SDP answer, m=audio, a=revonly.

[0041] After sending the SIP 183, the UE shall apply a preconfigured alerting behavior for receiving the silent calls / SMS, e.g., not make any ringing signal noise but instead discreetly vibrate and / or visualize in the call-UI, that this is an emergency silent call / message back, including a prompt e.g., red and green phone buttons, for the user to reject or accept the silent call / message. If the user accepts, the UE will send any sound and / or video captured by the microphone and / or camera of the UE, over the voice channel up to the PSAP agent or first responder person, via the operator NW.

[0042] The UE may register IMS silent call or / and silent message capability with its Home Public Land Mobile Network (HPLMN) by SIP registration process, as shown in Figure 3. The silent call / message capability is the ability of the UE to understand the silent call or message feature tag found in a received SIP message, e.g. a silent call feature tag in the Accept-Contact header of a SIP INVITE request, a silent message feature tag in Accept- Contact header of an SIP MESSAGE or a value of message protocol identifier in an SIP MESSAGE indicating it is a silent message, where it knows how to behave i.e. to supress an audible signal and just indicate to the end-user about the received call or message, by e.g. visual information or optionally a careful vibrate to get the end-user's attention. The UE can indicate its capability of silent call or / and silent message, at the time the UE makes an initial IMS registration to the IMS network. The indication may be implemented by a feature tag 'silent call / message' in the Contact header of the SIP REGISTER message. If a UE supports both silent call and silent message, it may include BOTH feature tags in the Contact header of the SIP REGISTER. The UE sends a SIP REGISTER request to the mobile NW. A silent call tag or a silent SMS tag or both silent call and SMS tags may be included in the Contact header of the SIP REGISTER message to indicate that the UE has silent call / SMS capability. The NW sends a response, typically a SIP 200 OK message, back to the UE to confirm that the registration was successful.

[0043] Figure 4 is a flow chart showing a method performed by a communication device of a PSAP or an emergency center or a first responder person, referred as PSAP communication device 140 hereafter, for handling communication between the PSAP communication device and a user communication device 110 via a communication network node 121 in a communication network 100. The method comprises one or more following actions which may be performed in any suitable order.

[0044] Action 410

[0045] The PSAP communication device 140 receives a message or a call request from the user communication device 110 via the communication network node 121. A user of the user communication device 110 may in a danger situation when he / she sent the message or made the call to the PSAP. The PSAP agent or personnel may want to get more information from the user to get a better understanding of the local scene circumstances without cause any danger to the user. So the PSAP agent decides to make a silent call back or send a silent SMS to the user and instruct the user communication device 110, e.g. a smartphone, to not ring or make any audible sound when receiving the silent call or message.

[0046] Action 420

[0047] The PSAP communication device 140 sends a request to the user communication device 110 via the communication network node 121. The request comprises an indication indicating that the request is a silent call or silent message request to the user communication device 110 without causing any audible sound on the user communication device. The silent call request may be implemented by e.g. a SIP INVITE request. The SIP INVITE request is a specific type of SIP message used to initiate a session, such as a voice or video call. When a user wants to start a session, their SIP client sends an INVITE request to the recipient, specifying the session parameters, such as the media types to be used and the desired session duration. The recipient's SIP client then processes the INVITE request and responds with a SIP message indicating whether the invitation is accepted, rejected, or redirected. The silent call indication may be implemented by a silent-call media feature tag in an AC header of the SIP INVITE request, e.g. SIP INVITE (AC: Silent call).

[0048] The silent message request may be implemented by an SIP MESSAGE with an embedded SMS. An SIP MESSAGE contains header fields and, optionally, a message body that carries additional information related to the communication session. When the PSAP communication device 140 sends a silent SMS message, it may insert the SMS inside an SIP MESSAGE according to what has been standardized for a mobile terminating SMS over IP, see e.g. GSMA IR.92, a technical profile developed by the GSM Association (GSMA) for voice and SMS over Long-Term Evolution (LTE) networks and SMS over IMS. The PSAP communication device 140 may include in an Accept-Contact header with a new 'silent message' feature tag.The silent message indication may also be implemented by setting a value of a protocol identifier (PID) of the SMS to indicate it is a silent message, e.g. a new value of the protocol identifier as specified in section 9.2.3.9 of 3GPP TS 23.040 may be set to indicate silent message, SIP MESSAGE (PID: Silent message). The PID is a field within the SMS protocol header that indicates the type or purpose of the SMS message. It is used to specify various parameters or features associated with the message. The protocol identifier typically consists of an octet (8 bits) that represents a numerical value. Different values of the protocol identifier are used to convey different meanings or functionalities of the SMS message. It's important to note that the interpretation of protocol identifier values may vary depending on the implementation and configuration of the SMS system. However, the protocol identifier plays a key role in determining how the SMS message is processed and displayed on the recipient's device.

[0049] According to some embodiments herein, the indication indicating that the request is a silent call or a silent message request may further comprise one or more explicit and require parameters to instruct the communication network node 121 to perform any one of the following actions: a) only forward the silent call / message request to a user communication device having silent call / message capability; b) reject the silent call if a user communication device does not have silent call / message capability.

[0050] The reason for this is to secure that the communication network node 121 only forwards the initial SIP request / SIP INVITE or SIP message with embedded SMS, to communication devices that has the silent call / message capability.

[0051] According to some embodiments herein, the indication indicating that the request is a silent call request may further comprises a tag, e.g. in the SDP offer, indicating any one of the following: a) receive-only direction on audio / video stream from the user communication device 110 to the PSAP communication device 140 via the communication network node 121 , e.g. SIP INVITE (AC: Silent call), SDP offer m=audio / video, a=revonly. This is to avoid the risk that any e.g., PSAP office background noise, reaches the called user’s smartphone speaker and gets audible, which could put the called user in great danger. b) both receive and transmit directions on audio / video stream between the user communication device 110 and the PSAP communication device 140 via the communication network node 121 , e.g. SIP INVITE (AC: Silent call), SDP offer m=audio / video, a=sendrecv.

[0052] Action 430

[0053] If the request is a silent call, the PSAP communication device 140 receives a first response, e.g. SIP 183 (session progress), from the user communication device 110 via the communication network node 121. The first response indicate the silent call request is being processed by the user communication device 110 and the PSAP communication device 140 should expect further responses.

[0054] If the request is a silent message, the SMS-center receives a first response from the user communication device 110 via the communication network node 121.

[0055] Action 440

[0056] The PSAP communication device 140 receives a second response, e.g. SIP 200, from the user communication device 110 via the communication network node 121. The second response is received after the user accepted the silent call. The second response indicates that a communication channel has been established between the PSAP communication device 140 and the user communication device 110.

[0057] Action 450 After the communication channel has been established between the PSAP communication device 140 and the user communication device 110, the PSAP communication device 140 receives audio and / or video stream captured by the user communication device 110 so that the PSAP agent is able to listen to or view it.

[0058] According to some embodiments herein, after the silent call has been answered, the PSAP agent may want to put questions to the user by text and want the user to answer in text or chat for the sake of keeping silence. Thus the PSAP agent has a voice / video channel and an MSRP channel. The voice / video channel is used by the PSAP agent for e.g. hearing the sounds from the surroundings of the user communication device 110 such as shooting sounds. The MSRP channel is used by the PSAP agent to send written questions in silence to the user and for the user to send answers in text to the PSAP agent via the mobile network. To realize this, the indication indicating that the request is a silent call request may further comprises an MSRP indication and / or an audio indication, and the method may further comprise the following actions:

[0059] Action 461

[0060] The PSAP communication device 140 receives a response from the user communication device 110 including an audio indication and / or an MSRP indications with valid transport IP addresses and ports.

[0061] Action 462

[0062] The PSAP communication device 140 receives one or more text messages from the user communication device 110 via the communication network node 121.

[0063] Another way to have both voice / video channel and MSRP channel is to add a chat channel to the silent call for the user communication device 110. Then the method may further comprises the following actions:

[0064] Action 463

[0065] The PSAP communication device 140 sends a second request, e.g. a SIP re- INVITE or SIP UPDATE message, to the user communication device 110 via the communication network node 121 during the silent call. The second request comprise a message indication indicating transport IP address or port and message protocol, e.g. re- INVITE may have a new m-line besides the m-line / s of the first request, e.g. a new m-line with “m=message 7654 TCP / MSRP”, where 7654 is the port and TCP / MSRP is the protocol, see section §8.1 of IETF specification RFC 4975.

[0066] Action 464 The PSAP communication device 140 sends one or more text messages to the user communication device 110 via the communication network node 121.

[0067] Action 465

[0068] The PSAP communication device 140 receives one or more text messages from the user communication device 110 via the communication network node 121.

[0069] A method performed in a user communication device 110 for handling communication between the user communication device 110 and a PSAP communication device 140 in a communication network 100 will be described with reference to Figure 5. The user communication device 110 is configured with silent call capability, i.e. the user communication device 110 can understand the silent call feature tag in a received call request and know how to behave i.e. to supress an audible signal caused by the call. Optionally, the user communication device 110 may also be configured with silent message capability if a silent message feature tag is implemented in the Accept-Contact header of SIP message. The method comprises one or more following actions which may be performed in any suitable order.

[0070] Action 510

[0071] The user communication device 110 may indicate its capability of silent call or / and message at the time the user communication device 110 makes an initial IMS registration to the IMS network 130 via the communication network node 121. The user communication device 110 sends a register request, e.g. a SIP REGISTER request, to the communication network node 121. The register request comprises an indication indicating that the user communication device 110 has a silent call or / and a silent message capability. If the user communication device 110 supports both silent call and silent message, it may include BOTH silent call and message feature tags in the Contact header of the SIP REGISTER request.

[0072] The silent call / message capability is the ability of the user communication device 110 to understand the silent call feature tag comprised in Accept-Contact header of a received SIP INVITE or a silent message feature tag comprised in Accept-Contact header of an SIP MESSAGE. When a new PID value is set in the message protocol identifier of an SIP MESSAGE with embedded SMS to indicate silent message, if the user communication device 110 does not understand it, the user communication device 110 will reject it, so it is not needed for the user communication device 110 to register its silent message capability. The user communication device 110 has a software module containing a SIP core or stack part and multiple SIP applications parts on top of that core. The former handles basic IMS SIP message i.e. INVITE, 200 OK, MESSAGE etc. The latter handles the IMS applications. The SIP core transfers the received SIP messages to the right application. For example, a SIP INVITE with audio can go to one application and a SIP MESSAGE with SMS can go to another application. Each application can control the speaker, microphone and camera of the user communication device 110. Hence, an application can omit generating any audible signal to the speaker, if the application found silent call or silent message indications in the received SIP message from the SIP core. The user communication device 110 can supress an audible signal and may just indicate to the end-user about the received call or message, by e.g. visual information or optionally a careful vibrate to get the end-user's attention.

[0073] Action 520

[0074] The user communication device 110 receives a response, typically a SIP 200 OK message, from the communication network node 121 indicating that the registration was successful.

[0075] Action 530

[0076] When a user of the user communication device 110 in a danger or emergency situation, he / she may want to send a text message or make a call to the PSAP depending on the actual situation. The user communication device 110 sends a text message or a call request to the PSAP communication device 140 via a communication network node 121 . The PSAP agent or personnel who received the text message or call may want to get more information from the user and decide to make a silent call back or send a silent SMS to the user without cause any danger to the user.

[0077] Action 540

[0078] The user communication device 110 receives a request, e.g. SIP INVITE or SIP MESSAGE, from the PSAP communication device 140 via the communication network node 121 . The request comprises an indication indicating that the request is a silent call or message request so that the user communication device 110 will not ring or make any audible sound when receiving the silent call / message.

[0079] Action 550

[0080] The user communication device 110 sends a first response, e.g. SIP 18x with SDP answer, to the PSAP communication device 140 via the communication network node 121 . The first response is a provisional responses to indicate that the requested action is still being processed or that further action is required before the request can be completed. SIP 18x may be e.g. SIP 180, SIP 181 , SIP 182, SIP 183. These SIP 18x provisional responses are used to provide status updates to the caller about the progress of the requested action, such as a call setup process. They help to manage the communication flow and inform the caller about the current state of the requested action until a final response, such as "SIP 200 OK" or an error response, is received.

[0081] The user communication device 110 may provide parameters in SDP answer corresponding to the parameters included in the silent call or message indication to indicate that a common view of a multimedia session between the user communication device 110 and PSAP communication device 140 has been established.

[0082] Action 560

[0083] The user communication device 110 process and analyze the request from the PSAP communication device 140. When the user communication device 110 detects the silent call or silent message indications in the received request, it can omit generating any audible signal to the speaker of the communication device 110. That is the user communication device 110 can supress audible signal and may indicate to the user about the received call or message, by e.g. visual information or optionally a careful vibrate to get the user's attention. When the user views the incoming call or message notification as a silent call / message displayed on the Ul with e.g. reject or accept buttons as usual, the user can reject or accept the call or message.

[0084] The indication may further comprise other tags or one or more explicit and require parameters for indicating: a) receive-only direction on audio / video stream from the user communication device 110 to the PSAP communication device 140; or b) both receive and transmit directions on audio / video stream between the user communication device 110 and the PSAP communication device 140 via the communication network node 121.

[0085] Then the user communication device 110 will take action based on these parameters. For example, in case a) the user communication device 110 will turn off the speaker and turn on the microphone and camera, and will only send audio / video stream to the PSAP communication device 140 without receiving any audio / video stream from the PSAP communication device 140.

[0086] Action 570

[0087] After have processed the received request and taken necessary actions based on the indication and other parameters, the user communication device 110 sends a second response, e.g. SIP 200 OK, to the PSAP communication device 140 via the communication network node 121 in response to an accept action made by a user of the user communication device 110. The SIP 200 response code indicates that the request has been successfully received, understood, and accepted by the recipient. It indicates that the call setup process has been successful and that the session is being established. That is when the user views the incoming call or message notification as a silent call / message displayed on the Ul and accept the call / message, the user communication device 110 sends a second response. This second response indicates a communication channel has been established between the user communication device 110 and PSAP communication device 140 via the communication network node 121.

[0088] Action 580

[0089] After the communication channel has been established between the user communication device 110 and PSAP communication device 140, the user communication device 110 sends the audio and / or video stream captured by the user communication device 110 to the PSAP communication device 140 via the communication network node 121. That is the audio sound captured by the microphone or / and video captured by the camera will be sent to the calling PSAP agent who is able to listen to or review it.

[0090] According to some embodiments herein, after the silent call has been answered, the PSAP agent may want to put questions to the user by text and want the user to answer in text or chat for the sake of keeping silence. To realize this, the indication indicating that the request is a silent call request may further comprises an MSRP indication and / or an audio indication, and the method may further comprise the following actions:

[0091] Action 591

[0092] The user communication device 110 send to the PSAP communication device 140 a response including an audio and / or an MSRP indication with valid transport IP addresses and ports in response to a silent call request comprising an audio indication and / or an MSRP indication.

[0093] Action 592

[0094] The user communication device 110 sends to the PSAP communication device 140 one or more text messages via the communication network node 121 .

[0095] According to some embodiments herein, the PSAP communication device 140 may add a chat channel to the silent call for the user communication device 110. Then the method may further comprises the following actions:

[0096] Action 593 The user communication device 110 receives a second request, e.g. a SIP re- INVITE or SIP UPDATE message from the PSAP communication device 140 via the communication network node 121 during the silent call. The second request comprises a message indication indicating transport IP address or port and message protocol.

[0097] Action 594

[0098] The user communication device 110 receives from the PSAP communication device 140 one or more text messages via the communication network node 121 .

[0099] Action 595

[0100] The user communication device 110 sends to the PSAP communication device 140 one or more text messages via the communication network node 121 .

[0101] To perform the method performed in the PSAP communication device 140 for handling communication between the PSAP communication device 140 and a user communication device 110 in a communication network 100, the PSAP communication device 140 comprises various modules as shown in Figure 6. For example, the PSAP communication device 140 may comprise a receiving module 610, a transmitting module 620, a processing module 640, a memory 650 etc.

[0102] The PSAP communication device 140 is configured to perform any one of the method actions 410-465 described above. The following are some example embodiments.

[0103] The PSAP communication device 140 is configured to, by e.g. the receiving module 610 being configured to, receive a message or a call request from the user communication device 110 via the communication network node 121.

[0104] The PSAP communication device 140 is configured to, by e.g. the transmitting module 620 being configured to, send a request to the user communication device 110 via the communication network node 121. The request comprises an indication indicating that the request is a silent call or silent message request to the user communication device without causing any audible sound on the user communication device 110.

[0105] The PSAP communication device 140 is configured to, by e.g. the receiving module 610 being configured to, receive a first response from the user communication device 110 via the communication network node 121 indicating that the request is being processed by the user communication device 110.

[0106] The PSAP communication device 140 is configured to, by e.g. the receiving module 610 being configured to, receive a second response from the user communication device 110 via the communication network node 121 , indicating that a communication channel has been established between the PSAP communication device 140 and the user communication device 110, and receiving 450 audio and / or video stream captured by the user communication device 110.

[0107] The method according to embodiments herein may be implemented through one or more processors together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of computer readable medium or a data carrier 680 carrying computer program code 670, as shown in Figure 6, for performing the embodiments herein when being loaded into PSAP communication device 140. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server or a cloud and downloaded to PSAP communication device 140.

[0108] To perform the method in the user communication device 110, the user communication device 110 comprises various function / application modules as shown in Figure 7. For examples, the user communication device 110 may comprise modules such as a receiving module 710, a transmitting module 720, a processing module 730, a memory 740, a microphone module 750, a camera module 760 etc.

[0109] The user communication device 110 is configured to perform any one of the method actions 510-595 described above. The following are some example embodiments.

[0110] The user communication device 110 is configured to, by means of e.g. transmitting module 720 being configured to, sends a message or a call request to the PSAP communication device 140 via a communication network node 121.

[0111] The user communication device 110 is configured to, by means of e.g. receiving module 710 being configured to, receive a request from the PSAP communication device 140 via the communication network node 121. The request comprises an indication indicating that the request is a silent call or message request to the user communication device 110.

[0112] If the received request is a silent call, the user communication device 110 is configured to, by means of e.g. transmitting module 720 being configured to, send a first response to the PSAP communication device 140 via the communication network node (121) indicating that the request is being processed or send a first response to a SMS- centre if the received request is a silent message request. The user communication device 110 is configured to, by means of e.g. processing module 730 being configured to, process the received request and taking actions based on the indication to supress any audible sound caused by the call or message.

[0113] If the received request is a silent call, the user communication device 110 is configured to, by means of e.g. transmitting module 720 being configured to, send a second response to the PSAP communication device 140 via the communication network node 121 in response to an accept action made by a user of the user communication device 110 indicating a communication channel has been established between the user communication device 110 and PSAP communication device 140 via the communication network node 121.

[0114] The user communication device 110 is configured to, by means of e.g. transmitting module 720 being configured to, send audio and / or video stream captured by the user communication device 110 to the PSAP communication device 140 via the communication network node 121.

[0115] The method according to embodiments herein may be implemented through one or more processors together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of computer readable medium or a data carrier 780 carrying computer program code 770, as shown in Figure 7, for performing the embodiments herein when being loaded into the user communication device 110. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server or a cloud and downloaded to the user communication device 110.

[0116] To summarize, embodiments herein provide a method for handling communication between a PSAP communication device and a user communication device in emergency situation. When the PSAP or an emergency center receives an SoS SMS or an SOS call from a user, the PSAP / emergency center can make a call or send an SMS back to the user without causing a ringing signal or any audible sound at the called communication device. The user communication device captures any sound and / or video from the microphone and camera of the user communication device once the user answers the call or SMS. In this way, the agent or personnel or first responder person of the PSAP / emergency center can get better understanding of the situation and provide better emergency help without cause any danger to the user. This may also save lives as a call or message back to a user with a phone that rings, would put the user in great danger at occasions of for example school, or warehouse shootings.

[0117] As used herein, the term “processing module” may refer to a processing circuit, a processing unit, a processor, an Application Specific integrated Circuit (ASIC), a Field- Programmable Gate Array (FPGA) or the like. As an example, a processor, an ASIC, an FPGA or the like may comprise one or more processor kernels. In some examples, the processing module may be embodied by a software module or hardware module. Any such module may be a determining means, estimating means, capturing means, associating means, comparing means, identification means, selecting means, receiving means, transmitting means or the like as disclosed herein. As an example, the expression “means” may be a module, such as a determining module, selecting module, etc.

[0118] As used herein, the expression “configured to” may mean that a processing circuit is configured to, or adapted to, by means of software configuration and / or hardware configuration, perform one or more of the actions described herein.

[0119] As used herein, the term “memory” may refer to a hard disk, a magnetic storage medium, a portable computer diskette or disc, flash memory, random access memory (RAM) or the like. Furthermore, the term “memory” may refer to an internal register memory of a processor or the like.

[0120] As used herein, the term “computer readable medium” may be a Universal Serial Bus (USB) memory, a DVD-disc, a Blu-ray disc, a software module that is received as a stream of data, a Flash memory, a hard drive, a memory card, such as a Memory Stick, a Multimedia Card (MMC), etc.

[0121] It will be appreciated that the foregoing description and the accompanying drawings represent non-limiting examples of the methods and apparatus taught herein. As such, the apparatus and techniques taught herein are not limited by the foregoing description and accompanying drawings.

Claims

Claims1 . A method performed by a public-safety answering point, PSAP, communication device (140) for handling communication between the PSAP communication device (140) and a user communication device (110) via a communication network node (121) in a communication network (100), the method comprising: receiving (410) a message or a call request from the user communication device (110) via the communication network node (121); sending (420) a request to the user communication device (110) via the communication network node (121), wherein the request comprises an indication indicating that the request is a silent call or silent message request to the user communication device without causing any audible sound on the user communication device (110); receiving (430) a first response from the user communication device (110) via the communication network node (121) indicating that the request is being processed by the user communication device (110); receiving (440) a second response from the user communication device (110) via the communication network node (121), indicating that a communication channel has been established between the PSAP communication device (140) and the user communication device (110); and receiving (450) audio and / or video stream captured by the user communication device (110).

2. The method according to claim 1 , wherein the silent call request is implemented by a Session Initiation Protocol, SIP INVITE message, and the indication is implemented by a silent-call media feature tag in an Accept-Contact header of the SIP INVITE message.

3. The method according to claim 1 , wherein the silent message request is implemented by a Session Initiation Protocol, SIP, MESSAGE with an embedded Short Message Service, SMS, and the indication is implemented by setting a value of a protocol identifier of the SMS and optional setting a silent-message feature tag in Accept-Contact header of the SIP MESSAGE.

4. The method according to any one of claims 1-2, wherein the indication indicating that the request is a silent call request further comprises one or more parameters to instruct the communication network node (121) to perform any one of the following: a) only forward the silent call request to a user communication device having silent call capability; b) reject the silent call if a user communication device does not have silent call capability;5. The method according to any one of claims 1-4, wherein the indication indicating that the request is a silent call request further comprises a tag indicating any one of the following: a) receive-only direction on audio / video stream from the user communication device (110) to the PSAP communication device (140) via the communication network node (121); b) both receive and transmit directions on audio / video stream between the user communication device (110) and the PSAP communication device (140) via the communication network node (121).

6. The method according to any one of claims 1-5, wherein the indication indicating that the request is a silent call request further comprises a Message Session Relay Protocol, MSRP, indication, and the method further comprises: receiving (461) a response from the user communication device (110) including a message indication with valid transport Internet Protocol, IP, addresses and ports; receiving (462) one or more text messages from the user communication device via the communication network node (121).

7. The method according to any one of claims 1-5, further comprising: sending (463) a second request to the user communication device via the communication network node (121) during the silent call, the second request comprises a message indication; sending (464) one or more text messages to the user communication device (110) via the communication network node (121); receiving (465) one or more text messages from the user communication device via the communication network node (121).

8. The method according to claim 7, wherein the second request is a SIP re-INVITE or SIP UPDATE message.

9. The method according to any one of claims 1-8, wherein the communication network (100) comprises a Short Message Service Center, SMS-C (160), and wherein the PSAP communication device (140) receives the text message from the user communication device via the SMS-C (160).

10. A method performed by a user communication device (110) for handling communication between the user communication device (110) and a public-safety answering point, PSAP, communication device in a communication network (100), wherein the user communication device (110) is configured with silent call capability, the method comprising: sending (530) a message or a call request to the PSAP communication device (140) via a communication network node (121); receiving (540) a request from the PSAP communication device (140) via the communication network node (121), wherein the request comprises an indication indicating that the request is a silent call or message request to the user communication device (110); if the received request is a silent call, sending (550) a first response to the PSAP communication device (140) via the communication network node (121) indicating that the request is being processed or sending (550) a first response to a SMS-centre if the received request is a silent message request; processing (560) the received request and taking actions based on the indication to supress any audible sound caused by the call or message; if the received request is a silent call, sending (570) a second response to the PSAP communication device (140) via the communication network node (121) in response to an accept action made by a user of the user communication device (110) indicating a communication channel has been established between the user communication device (110) and PSAP communication device (140) via the communication network node (121); sending (580) audio and / or video stream captured by the user communication device (110) to the PSAP communication device (140) via the communication network node (121).11 . The method according to claim 10, further comprises: sending (510) a register request to the communication network node (121), wherein the register request comprises an indication indicating that the user communication device (110) has a silent call or / and silent message capability; receiving (520) a response from the communication network node (121) indicating that the registration was successful.

12. The method according to any one of claims 10-11 , further comprises: sending (591) to the PSAP communication device (140) a response including an audio indication and / or a message indication with valid transport IP addresses and ports in response to a silent call request comprising an audio indication and / or an MSRP indication; sending (592) to the PSAP communication device (140) one or more text messages via the communication network node (121).

13. The method according to any one of claims 10-11 , further comprises: receiving (593) a second request from the PSAP communication device (140) via the communication network node (121) during the silent call, the second request comprises a message indication; receiving (594) from the PSAP communication device (140) one or more text messages via the communication network node (121); sending (595) to the PSAP communication device (140) one or more text messages via the communication network node (121).

14. A PSAP communication device (140) configured to perform the method according to any one of claims 1-9.

15. A user communication device (110) configured to perform the method according to any one of claims 10-13.

16. A computer program product (680) comprising program code (670) for performing, when executed by a processing module (640) in the PSAP communication device (140), the method of any one of claims 1-9.

17. A non-transitory computer-readable storage medium (670) comprising instructions, which when executed by a processing module (640) in the PSAP communication device (140), cause the processing module to perform the method of any one of claims 1-9.

18. A computer program product (780) comprising program code (770) for performing, when executed by a processing module (740) in the user communication device (110), the method of any one of claims 10-13.

19. A non-transitory computer-readable storage medium (770) comprising instructions, which when executed by a processing module (740) in the user communication device (110), cause the processing module to perform the method of any one of claims 10-13.

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