Network node, communication device and methods therein for handling connectivity in isolated network operation

Abstract

Network node (130), communication device and methods for handling connectivity and services in a wireless communication network (100, 200) are provided. The network node (130) and communication device (UE) are configured with isolated network operation mode. The network node (130) initiates the isolated network operation mode when detecting a disconnection from a core network and sends a message comprising an indication indicating the network node (130) is in the isolated network operation mode and scheduling information of one or more System Information Blocks (SIBx) to one or more communication devices (UE1, UE2, UE3, UE4). The network node (130) receives a connection setup request from a communication device (UE) and transmits connection setup information to the communication device (UE1). The network node (130) receives a connection setup complete message from the communication device (UE1), wherein the connection setup complete message comprises a dedicate message. The network node (130) analyzes the dedicate message; and in response thereto, taking actions to set up connection for message or voice / video service for one or more communication devices (UE1, UE2, UE3, UE4) configured with isolated network operation mode in a coverage cell (150) of the network node (130).

Description

[0001] NETWORK NODE, COMMUNICATION DEVICE AND METHODS THEREIN FOR

[0002] HANDLING CONNECTIVITY IN ISOLATED NETWORK OPERATION

[0003] TECHNICAL FIELD

[0004] Embodiments herein relate to network node, communication devices and methods therein for handling connectivity in a wireless communication network. In particular, embodiments herein relate to handling connectivity in Isolated Network Operation in disaster situations.

[0005] BACKGROUND

[0006] In a typical mobile communication network or system, wireless devices, also known as wireless communication devices, mobile stations, and / or user equipment (UE), communicate via a Radio Access Network (RAN) to one or more core networks (CN). The RAN covers a geographical area which is divided into service areas or cell areas, which may also be referred to as a beam or a beam group, with each service area or cell area being served by a radio network node such as a radio access node e.g., a Wi-Fi access point or a radio base station (RBS), which in some networks may also be denoted, for example, a “NodeB” or “eNodeB” or “gNB”. A service area or cell area is a geographical area where radio coverage is provided by the radio network node. The radio network node communicates over an air interface operating on radio frequencies with the wireless communication devices within a range of the radio network node.

[0007] Figure 1 shows an example mobile communication network 100. The mobile communication network 100 comprises a core network CN 110, a mobile backhaul network MBN 120, a radio access network comprising one or more network nodes RAN 130, 131 and one or more communication devices 140, 141. The mobile communication network 100 provides services via network functions in the core network 110, such as Access and Mobility Management Function AMF, Session Management Function SMF, User Plane Function UPF etc. These network functions can be realized in physical network function nodes or in virtualized network functions. There is a tremendous effort done, to ensure that redundancy and resiliency is kept to a high degree, because of the significance of the core network functions for the mobile operator.

[0008] The core network 110 interconnects those network functions and spreads their availability to the RAN node 130 with a coverage area, i.e. a cell 150, via the mobile backhaul network 120. The services for the mobile user, e.g. UE 140, 141 which is located in the cell 150 of the radio access network node 130, are realized with the network functions in the core network 110. The radio access network node 130 ensures the connectivity via air interface, and the different RAN nodes 130, 131 are connected to the core network 110 via the mobile backhaul network 120 through one or more routers R 160, R 161.

[0009] In order to deliver services to a UE, all parts of the mobile communication network 100 must be functional and connectivity between all parts must be available. In disaster situations, the connectivity of backhaul network may be cut off leaving the communication devices 140, 141 with no services whatsoever.

[0010] Resilient 5thgeneration (5G) systems are always available, reliable, performs as expected, and recovers quickly when facing disturbances. The technical capabilities of a resilient 5G system include a combination of reliability, availability, robustness and security. These fundamental properties are inherent within telecom networks today and are extended even further with new technologies and capabilities.

[0011] Existing critical functions in society are being moved into the digital domain, becoming dependent on telecom networks. At the same time, new capabilities are enabling new use-cases to be realized. This is driving the evolution of traditional telecom networks into the primary innovation platform for both industry and society. This has led to various new demands on the 5G system, particularly mission and business critical use cases. Business critical related use cases will suffer, in most of occasions, from economic losses when there is a failure in the communication whereas mission critical related ones could end up in harmed people or even worse scenarios.

[0012] In disaster situations, at least the connectivity of backhaul network may be cut off. If a radio site, i.e. a radio network node, is cut-off from the core network, the user immediately loses all communication services. The network node in this case became an isolated network node and its one or more cells are referred as isolated cell(s).

[0013] Robustness, resilience and how to maintain the network always available become extremely relevant topics in today's networks.

[0014] The 3GPP standardized Isolated Evolved UMTS Terrestrial Radio Access (E- UTRAN) Operation for Public Safety (IOPS) is a wireless communication standard developed specifically for emergency and public safety services. It is designed to provide a high-performance network with high-speed data transfer, reliable voice communication, and advanced security features for first responders and other public safety agencies. However, It requires a complete packet core in the radio base station or radio access network node. This is costly to implement, maintain and operate. SUMMARY

[0015] Therefore it is an object of embodiments herein to provide an improved isolated network operations for public safety in a wireless communication network.

[0016] Embodiment herein provide a method for handling connectivity in disaster or emergency situations when the core network is unavailable such that communication services e.g. message, voice, video services etc. are still available in such disaster scenarios. In case of disaster, e.g. natural or man-made, or unexpected emergency situations, message or voice / video service continues and will continue being the most demanded and important service for first responders and rescue forces. Message or voice / video service must be up and running under any circumstance even if the rest of services are down.

[0017] According to one aspect of embodiments herein, the object is achieved by a network node and method therein for handling connectivity and / or services for a communication device in a wireless communication network. The network node and communication device are configured with isolated network operation mode. The network node initiates the isolated network operation mode in response to detecting a disconnection from a core network. The network node sends a message comprising indication indicating the network node is in the isolated network operation mode and scheduling information of one or more System Information Blocks (SIBs), e.g. a new or specific or dedicated SIBx, to one or more communication devices. The network node receives a connection setup request from a communication device and transmits connection setup information to the communication device. The network node further receives a connection setup complete message from the communication device. The connection setup complete message comprises a dedicate message. The network node analyze the dedicate message and in response to the analysis, taking actions to set up connection for the communication device to one or more other communication devices configured with isolated network operation mode in a coverage cell of the network node.

[0018] According to one aspect of embodiments herein, the object is achieved by a communication device and method therein for handling connectivity to one or more other communication devices via a network node in a wireless communication network. The communication device is configured with isolated network operation mode. The communication device receives a message from the network node. The message comprises indication indicating the network node is in the isolated network operation mode and scheduling information of one or more system information blocks SIBx. The communication device sends a connection setup request to the network node and receives connection setup information from the network node. The communication device further sends a connection setup complete message to the network node. The connection setup complete message comprises a dedicate message. The communication device further monitors a system information block SIBx based on the received scheduling information of the one or more SIBx and takes actions based on the information comprised in the SIBx.

[0019] According to some embodiments herein, the dedicate message may comprise a message string comprising text and / or token, or the dedicate message may comprise a registration message comprising a string indicating a subscriber identity. Depends on the content of the dedicate message, the network node connects users in the isolated cell to each other for message or voice / video services. A user of communication device can send a message e.g. text string to the network node and the network node broadcasts this message to all other users in the cells served by the network node. All users in the cell can receive messages and act or inform e.g. rescue officials. A user can register its subscriber identity in the network node. The subscriber identity may be provided as a string which may contain a meaningful identity, like doctor, hiking expert, dentist etc. The network node may inform all users about subscriber identities of all registered users in the isolated cell by broadcasting a message comprising subscriber identities of all registered users in a scheduled SIBx. The users can read the message in the SIBx and update its telephone book. A user can originate a mobile call towards a terminating mobile subscriber, which has previously registered in the isolated cell. This call does not require any external Internet Protocol (IP) Multimedia Subsystem (IMS) or core network. It is based on direct layer 2 connection between two communication devices setup by the network node as a bridge.

[0020] According to embodiments herein, when a network node is disconnected from the core network, the network node is falling back to an “isolated mode operation”. The network node broadcasts its new mode of operation and schedule information of a new or specific or dedicated SIBx. The communication device supporting isolated mode operation can connect to the network node.

[0021] In one example, a user may send emergency messages to the radio network node which broadcasts the message to other users in the same cell or in every cell that this specific network node serves. Other users in the cell can reply to such messages by uploading new messages to the radio network node which will broadcast that message. Users can select name aliases on their own discretion which are appended to messages and used to identify individual users.

[0022] In one example, a user may register its subscriber identity in the network node. The network node provides subscriber identities of registered users to all other users. A user can trigger mobile originating calls towards registered users in the cell and a user can be called from registered users in the cell.

[0023] Embodiments provides some advantages, for examples:

[0024] Embodiments herein provide means to the radio access network node to broadcast an emergency help request from one user to another user, for example a rescue team, in the same cell.

[0025] Embodiments herein provide means to the radio access network node to connect users in the isolated cell to each other for voice / video services.

[0026] Embodiments herein provide a chance for emergency help in urgent need for special users and / or normal users, as long as UEs and network nodes support this new isolated operation feature.

[0027] Embodiments herein provide a lightweight software update of radio access network node function, easily deployable on all nodes in the RAN.

[0028] Embodiments herein enable emergency voice / video communication or call service between registered users provided by the network node without core network within a cell.

[0029] Embodiments herein provide emergency broadcast service when no other service is available from the wireless communication network.

[0030] Embodiments herein provide simple communication without core network within a cell.

[0031] Embodiments herein provide simpler approach to existing solutions for public warning systems.

[0032] Therefore, embodiments herein provide an improved method for isolated network operations for public safety in a wireless communication network. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Examples of embodiments herein are described in more detail with reference to attached drawings in which:

[0034] Figure 1 is a schematic block diagram depicting an example of a mobile communication network;

[0035] Figure 2 is a schematic block diagram depicting an example of an isolated network with an isolated network node and its isolated cell;

[0036] Figure 3 is a signal flowchart according to embodiments herein;

[0037] Figure 4 is a signal flowchart illustrating an example embodiment;

[0038] Figure 5 is a signal flowchart illustrating an example embodiment;

[0039] Figure 6 is a signal flowchart illustrating an example call establishing procedure;

[0040] Figure 7 is a flowchart illustrating a method performed in a network node according to an embodiment herein;

[0041] Figure 8 is a flowchart illustrating a method performed in a network node according to an embodiment herein;

[0042] Figure 9 is a flowchart illustrating a method performed in a communication device according to embodiments herein;

[0043] Figure 10 is a schematic block diagram illustrating one embodiment of a network node; Figure 11 is a schematic block diagram illustrating one embodiment of a communication device.

[0044] DETAILED DESCRIPTION

[0045] 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.

[0046] The terms “communication device”, “wireless device”, “UE”, “user equipment”, “terminal equipment”, “wireless terminal” and “terminal” may be used interchangeable herein.

[0047] The RAN node 130, 131 shown in Figure 1, 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, IAB- donor Distributed Unit (lAB-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.

[0048] The network node 130 provides radio coverage over a geographical area, i.e. a service area or service cell 150, which may also be referred to as a beam or a beam group where the group of beams is covering the service area of a radio access technology (RAT). The network node 130 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 130 depending e.g. on the radio access technology and terminology used.

[0049] The terms “network node”, “RAN node”, “radio network node”, “gNB” may be used interchangeable herein.

[0050] As part of developing embodiments herein problems is identified and will first be discussed.

[0051] When there is a network outage in the mobile backhaul network 120, as shown in Figure 1 , indicated by reference number 170, due to e.g. natural forces like earthquakes, fires, floods or malfunction of devices, power failure, misconfiguration etc, which result in failure of a non-redundant device or connection. The outcome is that the network node, e.g. the RAN node 130 loses the connectivity to the core network 110. This failure may be close to the network node site as indicated, but may also higher up in the hierarchy in direction to the core network 110. In this case, the network node 130 became isolated node and its cell became isolated cell.

[0052] When a radio base station still has power e.g. batteries or solar panels, some basic services should still be offered to local users, however, with the current 3GPP architecture and specified functions this is not possible because the core network nodes are mandated for any service to function.

[0053] According to embodiments herein, when the network node 130 realizes the loss of the connection to the core network 110, from this moment onwards, new services, i.e. Isolated Network Operation for message, voice / video are offered to the mobile users in the radio cells 150 controlled by the network node 130. Figure 2 is a schematic block diagram showing an example of isolated communication network 200 with the isolated network node 130 and one or more isolated cells e.g. the cell 150 which provide Isolated Network Operation services for one or more communication devices UE1, UE2, UE3, UE4. The isolated cell may be isolated cells from one and the same network node 130 which survived the outage case. The network node 130 and communication devices UE1, UE2, UE3, UE4 are configured with isolated network operation mode. That is an isolated network operation application or function is implemented in the network node 130 and communication devices UE1 , UE2, UE3, UE4. In other words, the network node 130 and communication devices UE1 , UE2, UE3, UE4 are supporting Isolated Network Operation for message voice / video services.

[0054] One way of implementing the Isolated Network Operation for message, voice / video may be that the network node 130 provides in a system information block e.g. the first system information block SIB1 , a new flag indicating Isolated Operation is available in this cell.

[0055] The network node 130 may in the first SIB1, also provide scheduling information for a new system information block, SIBx, which may also be referred as a specific or dedicated SIB. SIBx may be any SIB, e.g. SIB10 or SIB11 etc. It is configurable if this SIBx is broadcasted or only send on request by a communication device as it is done for any other SIB messages, e.g. SIB2-SIB9 messages.

[0056] All communication devices, e.g. communication devices UE1, UE2, UE3, UE4 in the cell 150, supporting Isolated Network Operation for messages and / or voice / video, will be able to read the information out of the new system information block SIBx.

[0057] The user who needs help and uses a communication device which supports Isolated Network Operation for messages and / or voice / video, can register in the isolated network 200. After registration, the user can originate a mobile call to a registered user in the isolated network 200, or it may receive a terminating call from a registered user. The user can also broadcast important text messages to anyone in the cell 150 to ask for help.

[0058] Figure 3 is a signal flow chart illustrating example procedures involved in the Isolated Network Operation for messages and / or voice / video services. The black boxes are procedures as in the normal case, whereas all bolded-text indications are added for new actions for the Isolated Network Operation for messages and / or voice / video services. Action 301

[0059] When the network node gNB 130 realizes the loss of the connection to the core network 110, it releases all connected UEs and indicates in SIB1 in the cell 150 that now Isolated Network Operation is possible. It also provides in the SIB1 the scheduling information of a new SIBx, for example periodic or on-demand-only, which is used to broadcast user specific emergency messages or broadcast information on all registered users in the Isolated Network 200.

[0060] Action 302

[0061] A UE supporting Isolated Network Operation, can select this network, in case no other network is available and select this network independent of broadcasted Public Land Mobile Network Identities (PLMN-IDs).

[0062] Action 303

[0063] A UE supporting Isolated Network Operation, can select this cell 150 as suitable cell and can camp on it.

[0064] Action 304

[0065] A random-access procedure is initiated as in the normal case. The difference here is that UEs not supporting Isolated Network Operation should not even start to access the network, as it would fail anyway. The cell 150 is only usable for Isolated Network Operation.

[0066] Action 305

[0067] Radio Resource Connection (RRC) Setup is requested by a UE for the new Isolated Network Operation services. As the network node 130 supports this new function, it provides RRC Setup information, and the UE continues with RRC Setup Complete, which contains a dedicated NAS message, in e.g. a octet string format. For different services, the dedicated NAS message may contain different message string with different information. For examples, the dedicated NAS message may comprise a message string with position or registration message. The message string may also be contained in any other applicable IE of this RRC Setup Complete message instead of the IE of the dedicated NAS message.

[0068] Action 306

[0069] The dedicated NAS message usually contain message string for the core network functions to decode or analyze. However, as this network node 130 is in Isolated Network Operation, the new Isolated Network Operation application / function will analyze this message string. The network node 130 will take actions to set up connection for the communication device UE1 to one or more other communication devices UE2, UE3, UE4 for message or voice / video service depends on the message string contained in the dedicated message. The connection for message does not need registration beforehand, and the connection for voice / video requires the communication device has been registered in the network node. The actions to set up connection for message or voice / video service will be described in the following.

[0070] For message service, the dedicated NAS message contains a message string with information which should be provided to other users in the cell 150. The network node 130 may take the following actions to set up connection for one or more communication devices, e.g. the communication device UE1, as shown in Figure 4.

[0071] Action 401

[0072] The network node 130 processes message to be broadcasted. The message string may comprise besides the actual text message or token, also control information which the network node 130 understands and acts upon. For example, the message string may contain next to the actual message a control information, like adding this message to broadcast or how many times the message shall be repeated, or information it shall be deleted. The network node 130 can add or remove information indicated by the control information from the broadcast. Further, the text message or token can include automatic appended information like the geographical position of the UE.

[0073] After the Isolated Network Operation application in the network node 130 removes the control information from the message string, it may add the message string in a message buffer which holds all messages from all users in the cell 150 that shall be broadcasted. The network node 130 then adds a message string from the message buffer into a SIBx which’s scheduling information has been broadcasted in SIB1 in Action 301.

[0074] Action 402

[0075] The new system information block SIBx, e.g. SIB10, is broadcasted to all UEs in all served cells of the network node 130, e.g. the cell 150. The messages within the message buffer of the network node 130 are transmitted via one or more scheduled SIBx.

[0076] Action 403

[0077] The communication devices UE1, UE2, UE3, UE4 within the served cells of the network node 130, e.g. the cell 150, supporting Isolated Network Operation can read the broadcasted SIBx and can display its content. The UE indicated in Figure 4 may be any UE or dedicated emergency rescue team UEs.

[0078] The messages may be stored in the UE and can be read on demand. An appended token in the message string might be used by a rescue team user of communication device to specifically answer a single UE using the same Isolated Network Operation functions.

[0079] For voice / video service, the dedicated NAS message contains a registration message with a string which indicates the subscriber identity of a UE. The network node 130 may take the following actions to set up connection for the communication device UE1, as shown in Figure 5.

[0080] Action 510

[0081] A registration procedure is initiated when the network node 130 realizes that the dedicated NAS message contains a registration message with a string which indicates the subscriber identity. The subscriber identity string may be freely chosen or may be described according to pre-defined rules of names. The registration procedure 510 comprises the following actions.

[0082] The new Isolated Network Operation application / function in the network node 130 receives and decodes, in Action 511 , this registration message.

[0083] As the registration message is decoded in the Isolated Network Operation application / function, it is also this new application / function which assigns, in Action 512, 5G-TMSI or 5G-S-TMSI which identifies the subscriber in the RAN to the UE. The 5G-S- TMSI is a shortened version of the 5G Globally Unique Temporary Identity (5G-GUTI), designed to facilitate efficiency in radio signaling procedures such as Paging and Service Request. The UE context with Cell Radio Network Temporary Identifier (C-RNTI), 5G- TMSI or 5G-S-TMSI and the subscriber identity string is set up, in Action 513. C-RNTI is a unique identifier used in Long Term Evolution (LTE) and New Radio (NR) networks to identify a specific UE within a particular cell. The C-RNTI reflects the radio bearer connection, whereas the 5G-TMSI or 5G-S-TMSI will be used in the paging procedure. A data base, e.g. a telephony server database, is updated with the UE context.

[0084] NAS register accept is communicated from the new Isolated Network Operation application / function to the existing RRC stack in the network node 130, in Action 515, and further communicated to the UE in Actions 516. NAS register complete is communicated from the UE to the existing RRC stack in the network node 130, in Action 517, and further communicated to the new Isolated Network Operation application / function in Actions 518. The registration procedure for a communication device is herein completed and the user is registered in the isolated network 200.

[0085] Action 520 The network node 130 broadcasts SIBx to all UEs in the cell 150, informing all users about subscriber identities of all registered users in the Isolated Network 200. The UEs can read the SIBx and keep updating its telephone book in case new information arrived.

[0086] The above actions describe the registration procedure for the Isolated Network Operation for voice / video service. After the registration procedure for a UE is completed, the UE can call another registered user and can be called by another UE. The network node 130 can set up a mobile call between two registered users, e.g. from UE1 to UE2. Figure 6 is a high-level signaling flow diagram illustrating a call establishing procedure between two communication devices e.g. UE1 and UE2.

[0087] When UE1 has been registered in the Isolated Network 200, it may trigger a mobile originating call request to the Isolated Network node gNB 130. The radio bearers are setup and as shown in Figure 6, a Session Initiation Protocol (SIP) message “Invite” is sent to a telephony server function of the Isolated Network Operation function / application in the network node 130.

[0088] On this level, when radio bearer connection to the network node 130 is established, the protocol being used might be a light-weight SIP message or a completely new defined protocol. The Subscriber Identity string provides the “telephone number” to enable the network node 130 to switch the call. “183 Session Progress”, “180 Ringing” and “200 Invite OK” are used in a light-weight SIP way to re-use existing protocol stacks in the UE / gNB, but at the end only basic functions of SIP as off-hook and ringing tone just need to be sent in the simplest form.

[0089] SIP or a SI P-light signaling variant for call control is one example. Other call control signaling protocols can be applied in a similar way such as Extensible Messaging and Presence Protocol (XMPP), H.323 or other possibly proprietary variants.

[0090] The telephony function needs look-up it’s data base, e.g. telephony server database, for the terminating subscriber identity. In the found UE context the stored 5G-S- TMSI / 5G-TMSI is used as in the normal case to page the subscriber.

[0091] Once, for each UE a radio bearer is established using C-RNTI, the Isolated Network Application / Function in the network node 130 will forward data packets between the 2 UEs acting as a bridge. The ringing tone is played on UE1, and when finally UE2 answers the call, the telephony function switches it’s two radio data bearers so that the voice / video call is switched-through. Figure 7 is a flow chart showing a method performed by a network node e.g. the network node 130 for handling connectivity and / or services for one or more communication devices UE1, UE2, UE3, UE4 in an isolated communication network 200 to provide Isolated Network Operation for message, voice / video services. The method comprises one or more following actions which may be performed in any suitable order.

[0092] Action 710

[0093] The network node 130 initiates the isolated network operation mode when it detects a disconnection from a core network 110, e.g. in response to detecting a disconnection between the network node 130 and the core network 110. When the network node 130 realizes the loss of the connection to the core network 110, it releases all connected UEs and indicates in a SIB e.g. SIB1, that now Isolated Network Operation for message, voice / video is possible. It also provides in the SIB1 the scheduling information of one or more SIBs, referred as SIBx herein, for example periodic or on-demand-only as a new SIB to broadcast user specific emergency messages or subscribe identities of registered users in the isolated network 200.

[0094] Therefore, according to some examples, the network node 130 may initiate the isolated network operation mode by releasing all connected communication devices UE1, UE2, UE3, UE4 and composing a message with indication indicating the network node 130 is in the isolated network operation mode. The message may be composed by adding in a SIB e.g. the first SIB1, an indication indicating isolated network operation mode. The message may further comprise scheduling information of one or more SIB as a new or specific or dedicated SIB referred as SIBx to broadcast information to all users in the isolated cell 150. For example, SIB10 or SIB11 may be used to broadcast information to all users in the isolated cell 150.

[0095] Action 720

[0096] The network node 130 send the message comprising indication indicating the network node 130 is in the isolated network operation mode and scheduling information of one or more SIB, SIBx, to one or more communication devices UE1, UE2, UE3, UE4 in the cell 150.

[0097] A communication device supporting Isolated Network Operation for message, voice / video can select this network node, in case no other network node is available and select this network node independent of PLMN-IDs, and can select this cell 150 to camp on it by initiating a random-access procedure as in the normal case.

[0098] Action 730 The network node 130 receives a connection setup request from a communication device, e.g. UE1 , which support Isolated Network Operation. For example, a RRC Connection Setup is requested by the UE1 for the new Isolated Network Operation services for message, voice / video.

[0099] Action 740

[0100] Upon receiving the connection setup request for the new Isolated Network Operation services for message, voice / video, the network node 130 transmits connection setup information about master cell group and radio bearer configuration to the communication device UE1 , as the it supports this new function. The UE1 continues with a RRC Setup Complete, which contains a dedicated message.

[0101] Action 750

[0102] The network node 130 receives a connection setup complete message from the communication device UE1. The connection setup complete message comprises a dedicate message, e.g. a dedicate Non-Access-Stratum (NAS) message.

[0103] If the connection setup request is for message service, the dedicate message may comprise a message string comprising text and / or token. The message string with information which should be provided to other users in the cell 150.

[0104] If the connection setup request is for voice / video service, the dedicate message may comprise a registration message comprising a string indicating a subscriber identity of the communication device UE1.

[0105] The dedicated NAS message contained in the connection setup complete message usually contains NAS message strings for the core network functions, but as the network node 130 is in the Isolated Network Operation mode, no communication to the core network 110, the isolated network operation application / function in the network node 130 will analyse this message string and act upon.

[0106] Action 760

[0107] The network node 130 analyzes the dedicate message, and in response to the analysis, taking actions to set up connection for the communication device UE1 to one or more other communication devices UE2, UE3, UE4 configured with isolated network operation mode in the coverage cell 150 of the network node 130.

[0108] In Isolated Network Operation for message service, a user may send a message e.g. text string, to the radio access network node 130. The radio access network node 130 can broadcast this message to all other users in the cells served by the radio access network node 130. All users in the cell 150 can receive the messages and act or inform rescue officials. In this case, the method may further comprise the following actions performed by the network node 130 to set up connection for the communication device UE1 to one or more other communication devices UE2, UE3, UE4 etc.

[0109] Action 770

[0110] The network node 130 adds the message string in a scheduled System Information Block SIBx which’s scheduling information has been indicated to one or more communication devices UE1 , UE2, UE3, UE4 by the SIB1 in Action 720.

[0111] The message string may comprise besides the actual text message or token for identifying the user, also control information which the network node 130 understands and acts upon. For example, the message string may contain next to the actual message also control information, like adding this message to broadcast or how many times the message shall be repeated, or information it shall be deleted.

[0112] If the message string comprises control information, the method may further comprise the following actions.

[0113] Action 771

[0114] The network node 130 analyzes the control information using the isolated network operation application / function in the network node 130.

[0115] Action 772

[0116] The network node 130 may process the message string by removing the control information and adding / deleting the information to be added / deleted indicated by the control information to / from the message string when adding the message string in a SIBx.

[0117] After the Isolated Network Operation application / function in the network node 130 removes the control information and the information to be deleted indicated by the control information from the message string, it may add the message string in a message buffer which holds all messages from all users in the cell 150 that shall be broadcasted. The message string in the message buffer is then added to a SIBx, e.g. SIB 10, for broadcasting. The network node 130 may directly add the message string to a SIBx without storing it in the message buffer.

[0118] Action 780

[0119] The network node 130 may broadcast the scheduled SIBx containing the message string to all communication devices e.g. UE2, UE3, UE4 configured with isolated network operation mode in the coverage cell 150 of the network node 130. It is configurable if the SIBx is broadcasted or only send on request by the communication device UE1 as it is done for any other SIB2-9 messages. All communication devices in the cell 150, supporting Isolated Network Operation, will be able to read the broadcasted messages out of the SIBx.

[0120] With the above described actions for Isolated Network Operation for message service, a user can send emergency messages to the radio network node 130 which broadcasts the message to other users in the same cell. The user who needs help and uses a UE which supports Isolated Network Operation, can broadcast important text messages to anyone in the cell to ask for help. Other users in the cell can reply to such messages by uploading new messages to the radio network node 130 which will broadcast that message. Users can select name aliases on their own discretion which are appended to messages and used to identify individual users.

[0121] In Isolated Network Operation for voice / video service, a user may register in the isolated network 200. The subscriber identity is provided as string which may contain a meaningful identity, like doctor, hiking expert, dentist etc. The isolated network node 130 may inform all users about the subscriber identities of all registered users in the isolated cell 150. The Isolated Network Operation for voice / video service makes it possible for a user to originate a mobile call towards a terminating mobile subscriber, which has previously registered in the isolated cell 150. In this case, the dedicate message received by the network node 130 may comprise a registration message comprising a string indicating a subscriber identity of a communication device, e.g. UE1 , and the method may further comprise the following actions to set up connection for the communication device UE1 to one or more other communication devices e.g. UE2, UE3, UE4 etc.

[0122] Action 790

[0123] The network node 130 decodes or analyzes the registration message using the Isolated Network Operation application / function. The registration message contains a message string which indicates the subscriber identity. In normal case, the RRC Setup Complete message sent by the communication device UE1 contains a dedicated NAS registration message which contains NAS string for the core network functions to decode or analyze. However, as the network node 130 is in the Isolated Network Operation mode, the new Isolated Network Operation application / function will analyze this registration message.

[0124] Action 791

[0125] The network node 130 updates a database with the subscriber identity of the communication device UE1 , e.g. a telephony server database. That is the subscriber identity of the communication device UE1 is added in the telephony server database. The telephony server database is built with a telephony entry per subscriber identity.

[0126] Action 792

[0127] The network node 130 assigns a TMSI, e.g. 5G-TMSI or 5G-S-TMSI, to the communication device UE1. As the registration message is decoded in the Isolated Network Operation application / function, it is also this new application / function which assigns the TMSI, 5G-TMSI or 5G-S-TMSI which identifies the subscriber in the RAN to the communication device UE1.

[0128] Action 793

[0129] The network node 130 sets up and store UE context for the communication device UE1. A data base entry is created for UE context of the communication device UE1 which may comprise C-RNTI, 5G-TMSI or 5G-S-TMSI and the subscriber identity string.

[0130] Action 794

[0131] The network node 130 sends a register accept message to the communication device UE1.

[0132] Action 795

[0133] The network node 130 receives a register complete message from the communication device UE1.

[0134] Action 796

[0135] The network node 130 broadcasts in a scheduled SIBx, a message comprising information on all registered users with communication devices supporting isolated network operation to all communication devices UE1, UE2, UE3, UE4 in the coverage cell 150 of the network node 130.

[0136] The communication devices UE1, UE2, UE3, UE4 in the coverage cell 150 of the network node 130 keep monitoring the SIBx and updating its telephone book in case new information on registered users arrived.

[0137] After the registration procedure is completed, the method may further comprise the following actions to set up a voice / video call between two registered users of the communication devices, e.g. UE1 and UE2, as shown in Figure 8.

[0138] Action 800

[0139] The network node 130 receives a call request from a first communication device, i.e. an originating communication device, which may be any one of the registered users of UE1 , UE2, UE3, UE4, e.g. UE1. For example, when UE1 has been registered in the Isolated Network 200, it may trigger a mobile originating call request to the Isolated Network node 130. The radio bearers are setup and as shown in Figure 6, a SIP message “Invite” is sent to the telephony server function in the Isolated Network Operation application / function. That is the communication device UE1 initiates a call and triggers a service request to the network node 130. An invitation, i.e. a call request, is sent to the network node 130.

[0140] Action 810

[0141] The network node 130 sets up radio bearers for the first originating communication device UE1.

[0142] Action 820

[0143] The network node 130 looks-up, in the database, e.g. the telephony server database, a subscriber identity of a second communication device, i.e. a terminating communication device, e.g. UE2, indicated in the call request.

[0144] Action 830

[0145] The network node 130 pages the second, i.e. the terminating communication device, e.g. UE2.

[0146] Action 840

[0147] The network node 130 sets up radio bearers for the second, i.e. the terminating communication device, e.g. UE2.

[0148] Action 850

[0149] The network node 130 forwards user payload, e.g. voice data packets between the first and second, i.e. the originating and terminating communication devices UE1, UE2.

[0150] A method performed in a communication device, e.g. UE1 for handling connectivity to one or more other communication devices e.g. UE2, UE3,UE4 via a network node, e.g. the network node 130 in a wireless communication network 200 will be described with reference to Figure 9. The network node 130, the communication device UE1 and one or more other communication devices UE2, UE3, UE4 are configured with isolated network operation mode. The method comprises one or more following actions which may be performed in any suitable order.

[0151] Action 900

[0152] The communication device UE1 receives a message from the network node 130. The message comprises indication indicating the network node 130 is in the isolated network operation mode and scheduling information of one or more System Information Blocks, SIBx. The message may be broadcasted or sent on demand by the network node 130 when it detects a disconnection from the core network 110. Action 910

[0153] The communication device UE1 selects the network node 130 as serving network node in case no other network is available. That is a communication device supporting Isolated Network Operation for message, voice / video can select this network node 130, in case no other network node is available and select this network node independent of broadcasted PLMN-IDs.

[0154] Action 920

[0155] The communication device UE1 selects the cell 150 of the network node 130 to camp on. That is a communication device supporting Isolated Network Operation for message, voice / video, can select this cell 150 as suitable cell and can camp on it by initiating a random-access procedure as in the normal case. The difference here is that communication devices not supporting Isolated Network Operation for message voice / video should not even start to access the network node, as it would fail anyway. The cell 150 is only usable for Isolated Network Operation for message voice / video.

[0156] Action 930

[0157] The communication device UE1 sends a connection setup request to the network node 130 as in the normal random-access procedure.

[0158] Action 940

[0159] The communication device UE1 receives connection setup information from the network node 130.

[0160] Action 950

[0161] The communication device UE1 sends a connection setup complete message to the network node 130. The connection setup complete message comprises a dedicate message.

[0162] For requesting message service, the communication device UE1 may add a message string comprising text and / or token as the dedicate message to the connection setup complete message. The message string with information which should be provided to other users in the cell 150.

[0163] For requesting voice / video service, the communication device UE1 may add a registration message comprising a message string indicating a subscriber identity of the communication device UE1 as the dedicate message to the connection setup complete message.

[0164] The network node 130 analyses the message string contained in the dedicate message and broadcasts information based on the the message string in a scheduled system information block SIBx. Action 960

[0165] The communication device UE1 monitors system information block SIBx based on the received scheduling information of the one or more system information blocks SIBx.

[0166] Action 970

[0167] The communication device UE1 takes actions based on the information comprised in the system information block SIBx. All communication devices in the cell 150, supporting Isolated Network Operation, will be able to read the broadcasted messages out of the SIBx.

[0168] In Isolated Network Operation for message service, a user can send emergency messages to the radio network node 130 which broadcasts the message to other users in the same cell. The user who needs help and uses a UE which supports Isolated Network Operation, can broadcast important text messages via the network node 130 to anyone in the cell to ask for help. Other users in the cell can reply to such messages by uploading new messages to the radio network node 130 which will broadcast that message. The messages may be stored on the network node 130 and then further broadcasted using one or more SIB to all users in the cell 150. Users can select name aliases on their own discretion which are appended to messages and used to identify individual users.

[0169] In this case, the dedicate message may comprise a message string comprising text and / or token and the information contained in the broadcasted SIBx is a message containing arbitrary text strings. The actions taken by the communication device UE1 based on the information comprised in the system information block SIBx may comprise the following actions.

[0170] Action 971

[0171] The communication device UE1 may display the content comprised in the system information block SIBx on the communication device UE1. The communication devices UE2, UE3, UE4 etc. within the cell 150 supporting Isolated Network Operation read the message in SIBx and can display its content. The communication device may be any UE or dedicated emergency rescue team UEs. The messages may be stored in the UE and can be read or displayed on demand.

[0172] Action 972

[0173] The communication device UE1 may send a message to the network node 130 which will broadcast the message to all users in the cell 150 of the network node 130 in one or more scheduled system information blocks SIBx. Instead of a message containing arbitrary text strings, the user of the communication device UE1 may as well add the position to the message, or the UE user interface offers predefined text snippets to ease communications. The message may further comprise automatic appended information on a geographical position of the communication device UE1. For example, a text message with “I broke my leg, cannot move, lying at the forest” with an automatic appended Global Positioning System (GPS) position will be very useful for the rescue team. The message may also comprise a meaningful identity indicating a job title of the subscriber, such as doctor, hiking expert, dentist etc. An appended token in the message may be used by the rescue team to specifically answer a single UE supporting the same functions of Isolated Network Operation.

[0174] The communication rules, the control information, between the Isolated Network Operation in the communication device and in the network node can be freely defined. Also the application in the communication device may provide pre-defined text blocks which are touched on the UE screen, and no free message typing would be necessary.

[0175] In Isolated Network Operation for voice / video service, a user may register its subscriber identity in the isolated network 200. The isolated network node 130 may inform all users in the isolated network 200 about subscriber identities of all registered users in the isolated cell 150. The Isolated Network Operation for voice / video service makes it possible for a user to originate a mobile call towards a terminating mobile subscriber, which has previously registered in the isolated cell 150. A user can be called from users registered in the isolated network. In this case, the dedicate message comprises a registration message comprising a string indicating a subscriber identity of a communication device, e.g. UE1 , and the information broadcasted in the scheduled SIBx comprises subscriber identities of all registered users in the isolated cell 150. The actions taken by the communication device UE1 based on the information comprised in the system information block SIBx may comprise the following actions.

[0176] Action 973

[0177] The communication device UE1 initiate a voice or video call to one or more registered users indicated in the system information block SIBx.

[0178] The subscriber identity may further comprise a meaningful identity indicating a job title of the subscriber, such as doctor, hiking expert, dentist etc. which make it easy to make a right call to a right person. The communication devices keep monitoring SIBx and updating its telephone book in case new information arrived.

[0179] To perform the method performed in the network node 130 for handling connectivity and / or services for a communication device UE1 in a wireless communication network 200, the network node 130 comprises various modules as shown in Figure 10. For examples, the network node 130 may comprise a receiving module 1010, a transmitting module 1020, a processing module 1040, a memory 1050 etc. The processing module 1040 may comprise function blocks such as Management of Radio Resources MRR 1041 , Scheduling of Resources allocated to mobile SR 1042, Interference Management IM 1043, Measurement Reports Management MRM 1044, etc. as in the existing design base. The processing module 1040 may further comprise a new function, i.e. an Isolated Network Operation function / application block INO 1045 which is capable of interfacing with the existing functions. The Isolated Network Operation function / application INO 1045 is used to provide message, and / or voice / video services in case the network node 130 is disconnected from the core network 110 and the network node 130 is in Isolated Network Operation mode. For examples, the Isolated Network Operation function / application INO 1045 may analyze the message string information contained in the dedicated NAS message, process and broadcast messages, build the telephony entry per subscriber identity, look-up mobile terminating user identity, trigger of paging and finally switch-through a call when terminating subscriber UE answers the call.

[0180] The network node 130 is configured to perform any one of the method actions 710- 850 described above. The following are some example embodiments.

[0181] The network node 130 is configured to, by e.g. the processing module 1040 being configured to, initiate the isolated network operation mode when detecting a disconnection from a core network 110.

[0182] The network node 130 is configured to, by e.g. the transmitting module 1020 being configured to, send a message comprising indication indicating the network node 130 is in the isolated network operation mode and scheduling information of one or more System Information Blocks SIBx to one or more communication devices UE1 , UE2, UE3, UE4.

[0183] The network node 130 is configured to, by e.g. the receiving module 1020 being configured to, receive a connection setup request from a communication device UE1.

[0184] The network node 130 is configured to, by e.g. the transmitting module 1020 being configured to, transmit connection setup information to the communication device UE1. The network node 130 is configured to, by e.g. the receiving module 1020 being configured to, receive a connection setup complete message from the communication device UE1 , wherein the connection setup complete message comprises a dedicate message.

[0185] The network node 130 is configured to, by e.g. the Isolated Network Operation function / application I NO 1045 in the processing module 1040 being configured to, analyze the dedicate message; and in response thereto, take actions to set up connection for the communication device UE1 to one or more other communication devices UE2, UE3, UE4 configured with isolated network operation mode in a coverage cell 150 of the network node 130.

[0186] 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 1080 carrying computer program code 1070, as shown in Figure 10, for performing the embodiments herein when being loaded into the network node 130. 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 network node 130.

[0187] To perform the method in the communication device UE1 , UE2, UE3, UE4, the communication device UE1 , UE2, UE3, UE4 comprises various function / application modules as shown in Figure 11. For examples, the communication device UE1 , UE2, UE3, UE4 may comprise modules such as a receiving module 1110, a transmitting module 1120, an antenna module 1130, a processing module 1140, a memory 1150, etc. The communication device UE1 , UE2, UE3, UE4 may further comprise an Air Interface Protocol Stack module AIPS 1141 as in the existing design base and a new function / application module for Isolated Network Operation, i.e. an Isolated Network Operation function / application module INO 1142 which is capable of interfacing with the existing function modules. The Isolated Network Operation function / application module INO 1142 may be a function implemented in the processing module 1140. The communication device UE1 , UE2, UE3, UE4 supports the updated RRC messages and also interworks with the new Isolated Network Operation application by inter-exchanging the information from / to the radio stack AIPS 1141 . The communication device UE1, UE2, UE3, UE4 is configured to perform any one of the method actions 900-973 described above. The following are some example embodiments.

[0188] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. receiving module 1110 being configured to, receive a message from the network node 130. The message comprises indication indicating the network node 130 is in the isolated network operation mode and scheduling information of one or more System Information Blocks SIBx.

[0189] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. the Air Interface Protocol Stack module Al PS 1141 being configured to, select the network node 130 as serving network node in case no other network is available.

[0190] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. the Air Interface Protocol Stack module AIPS 1141 being configured to, select a cell 150 of the network node 130 to camp on.

[0191] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. transmitting module 1120 being configured to, send a connection setup request to the network node 130.

[0192] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. receiving module 1110 being configured to, receive connection setup information from the network node 130.

[0193] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. transmitting module 1120 being configured to, send a connection setup complete message to the network node 130. The connection setup complete message comprises a dedicate message.

[0194] The communication device UE1, UE2, UE3, UE4 is configured to, by means of e.g. receiving module 1110 being configured to, monitor system information block SIBx based on the received scheduling information of the one or more system information blocks SIBx.

[0195] The communication device UE1, UE2, UE3, UE4 is configured to take actions based on the information comprised in the system information block SIBx.

[0196] The actions may be displaying the content comprised in the system information block SIBx on the communication device; or sending a message to the network node 130 which broadcasting the message to all users in the cell of the network node 130; or initiating a voice or video call to one or more registered users. 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 1180 carrying computer program code 1170, as shown in Figure 11 , for performing the embodiments herein when being loaded into the communication device UE. 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 communication device UE.

[0197] To summarize, according to embodiments herein, when a network node 130 is disconnected from the core network 110, the network node 130 is falling back to an “isolated network operation mode”. The network node 130 broadcasts its new mode of operation and schedule information of a new or specific or dedicated system information block, SIBx. The communication devices supporting isolated mode operation can connect to the network node 130. A user may send emergency messages to the radio network node 130 which broadcasts the message to other users in the same cell. Other users in the cell can reply to such messages by uploading new messages to the radio network node 130 which will broadcast that message. A user may register its subscriber identity in the network node 130. The network node 130 provides subscriber identities of registered users to all other users in the same cell. After registration, a user can trigger a call towards registered users in the same cell and a user can be called from registered users in the same cell.

[0198] Embodiments herein provide means to a radio access network node to broadcast an emergency help request from one user to another user, for example a rescue team, in the same cell.

[0199] Embodiments herein provide means to a radio access network node to connect users in the isolated cell to each other for voice / video services.

[0200] Embodiments herein provide a chance for emergency help in urgent need for special users and / or normal users, as long as UEs and network nodes support this new isolated operation feature.

[0201] Embodiments herein provide a lightweight software update of radio access network node function, easily deployable on all nodes in the RAN. Embodiments herein enable emergency voice / video communication or call service between registered users provided by a network node without core network within a cell.

[0202] Embodiments herein provide emergency broadcast service when no other service is available from the wireless communication network.

[0203] Embodiments herein provide simple communication without core network within a cell.

[0204] Embodiments herein provide simpler approach to existing solutions for public warning systems.

[0205] 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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 in a network node (130) for handling connectivity and / or services for a communication device (UE1) in a wireless communication network (100, 200), wherein the network node (130) and communication device (UE1) are configured with isolated network operation mode, the method comprising: initiating (710) the isolated network operation mode in response to detecting a disconnection from a core network (110); sending (720) a message comprising an indication indicating the network node (130) is in the isolated network operation mode and scheduling information of one or more System Information Blocks (SIBx) to one or more communication devices (UE1 , UE2, UE3, UE4); receiving (730) a connection setup request from a communication device (UE1); transmitting (740) connection setup information to the communication device (UE1); receiving (750) a connection setup complete message from the communication device (UE1), wherein the connection setup complete message comprises a dedicate message; analyzing (760) the dedicate message; and in response to the analyzing, taking actions to set up connection for the communication device (UE1) to one or more other communication devices (UE2, UE3, UE4) configured with isolated network operation mode in a coverage cell (150) of the network node (130).

2. The method according to claim 1 , wherein initiating (710) the isolated network operation mode comprises: releasing all connected communication devices; composing the message by adding in a first System Information Block (SIB1) an indication indicating isolated network operation mode and scheduling information of the one or more System Information Blocks (SIBx).

3. The method according to claim 2, wherein the dedicate message comprises a message string comprising text and / or token, and wherein taking actions to set up connection for the communication device (UE1) comprises:adding (770) the message string in a scheduled System Information Block (SIBx) which’s scheduling information has been provided to one or more communication devices (UE1 , UE2, UE3, UE4); and broadcasting (780) the scheduled System Information Block (SIBx) to all communication devices (UE2, UE3, UE4) configured with isolated network operation mode in the coverage cell (150) of the network node (130).

4. The method according to claim 3, wherein the message string further comprises automatic appended information on a geographical position of the communication device.

5. The method according to any one of claims 3-4, wherein the message string further comprises control information, and wherein the method further comprises: analyzing (771) the control information; processing (772) the message string by removing (772) the control information and adding / deleting the information to be added / deleted indicated by the control information to / from the message string before adding it to a scheduled System Information Block (SIBx).

6. The method according to claim 2, wherein the dedicate message comprises a registration message comprising a string indicating a subscriber identity of the communication device (UE1), and wherein taking actions to set up connection for the communication device (UE1) comprises: decoding (790) the registration message; updating (791) a database with the subscriber identity of the communication device (UE1); assigning (792) a Temporary Mobile Subscriber Identity, TMSI, to the communication device (UE1); setting up (793) context for the communication device (UE1); sending (794) a register accept message to the communication device (UE1); receiving (795) a register complete message from the communication device (UE1);broadcasting (796) in a scheduled System Information Block (SIBx), a message comprising information on all registered users of communication devices supporting isolated network operation to all communication devices in the coverage cell (150) of the network node (130); receiving (800) a call request from a first communication device (UE1); setting up (810) radio bearers for the first communication device (UE1); looking-up (820), in the database, a subscriber identity of a second communication device (UE2) indicated in the call request; paging (830) the second communication device (UE2); setting up (840) radio bearers for the second communication device (UE2); forwarding (850) data packets between the first and second communication devices (UE1 , UE2).

7. A method performed in a communication device (UE1) for handling connectivity to one or more other communication devices (UE2, UE3, UE4) via a network node (130) in a wireless communication network (100, 200), wherein the communication device (UE1) is configured with isolated network operation mode, the method comprising: receiving (900) a message from the network node (130), wherein the message comprises an indication indicating the network node (130) is in the isolated network operation mode and scheduling information of one or more System Information Blocks (SIBx); sending (930) a connection setup request to the network node (130); receiving (940) connection setup information from the network node (130); sending (950) a connection setup complete message to the network node(130), wherein the connection setup complete message comprises a dedicate message; monitoring (960) System Information Block (SIBx) based on the received scheduling information of the one or more System Information Blocks (SIBx); taking actions (970) based on the information comprised in the System Information Block (SIBx).

8. The method according to claim 7, wherein the dedicate message comprises a message string comprising text and / or token, and wherein taking actions based on the information comprised in the System Information Block comprises:displaying (971) the content comprised in the System Information Block (SIBx) on the communication device; or sending (972) a message to the network node (130) for broadcasting the message to all users in the cell (150) of the network node (130) in a scheduled System Information Block (SIBx).

9. The method according to claim 8, wherein the message string further comprises automatic appended information on a geographical position of the communication device.

10. The method according to claim 8, wherein the message string further comprises a meaningful identity indicating a job title of the subscriber.

11. The method according to claim 7, wherein the dedicate message comprises registration message comprising a string indicating a subscriber identity of the communication device (UE1), and wherein taking actions based on the information comprised in the system information block (SIBx) comprises: initiating (973) a voice or video call to one or more registered users indicated in the System Information Block (SIBx).

12. The method according to claim 11, wherein the subscriber identity further comprises a meaningful identity indicating a job title of the subscriber.

13. A network node node (130) for handling connectivity and services for a communication device (UE1) in a wireless communication network (100, 200), wherein the network node (130) and communication device (UE1) are configured with isolated network operation mode, the network node node is configured to perform the method according to any one of claims 1-6.

14. A communication device (UE1) for handling connectivity to one or more other communication devices (UE2, UE3, UE4) via a network node (130) in a wireless communication network (100, 200), wherein the network node (130), the communication device (UE1) and one or more other communication devices (UE2, UE3, UE4) are configured with isolated network operation mode, the communication device (UE1) is configured to perform the method according to any one of claims 7-12.

15. A computer program product (1080) comprising program code (1070) for performing, when executed by a processing module (1040), the method of any one of claims 1-6.

16. A non-transitory computer-readable storage medium (1070) comprising instructions, which when executed by a processing module (1040), cause the processing module to perform the method of any one of claims 1-6.

17. A computer program product (1180) comprising program code (1170) for performing, when executed by a processing module (1140), the method of any one of claims 7-12.

18. A non-transitory computer-readable storage medium (1170) comprising instructions, which when executed by a processing module (1140), cause the processing module to perform the method of any one of claims 7-12.

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