Method for energy efficient spectrum sharing

Abstract

An apparatus comprises means for providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, in which at least one random access preamble is stored in the apparatus, the at least one random access preamble indicates a request to be redirected to a second cell supporting at least a second radio access technology; means for sending signaling information to the at least one user equipment via the first radio access technology, wherein the signaling information comprises information for establishing a connection to the second cell; means for receiving a random access preamble from the at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least a second radio access technology; means for transmitting to the second cell an indication of a transition to an active state; and means for sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response comprises signaling for redirecting the user equipment to camp on a second cell supporting at least a second radio access technology.

Description

Technical Field

[0001] The present disclosure relates to spectrum sharing procedures. Background Art

[0002] Throughout the history of 3GPP networks, there has been an ongoing migration towards next generation radio access technologies (RATs). This has challenged network operators regarding their decisions about when and to what extent to invest in next generation RATs. Dynamic spectrum sharing (DSS) was introduced in 3GPP Release 15 to provide a migration path from 4G / LTE (fourth generation / long term evolution) to 5G / NR (fifth generation / new radio) by allowing LTE and NR to share the same carrier.

[0003] In the initial stage of deploying a new RAT such as 5G / NR, DSS is usually deployed on low frequency bands to enable the expansion of new RAT coverage. For example, when the 5G / NR user equipment (UE) market penetration is low, that is, most users adopt 4G / LTE devices, the activation of 5G on the cell should introduce minimal overhead.

[0004] However, in 4G-5G DSS, the 5G DSS cell must continuously transmit downlink signals (such as synchronization and system information signals and messages) without being aware of any 5G-capable UEs in its area, which inevitably reduces the available radio resource capacity for 4G / LTE connections. Although there are usually only a few or even no 5G-capable UEs, the 5G DSS cell provides a constant overhead in the DSS cell. This reduces the perceived performance of the 4G / LTE UE and generates additional power consumption due to DL transmission. Summary of the invention

[0005] Now, an improved method and technical apparatus for implementing the method has been invented, by which the above-mentioned problems are alleviated. Various aspects include a method, an apparatus and a non-transitory computer-readable medium comprising a computer program or a signal stored therein, characterized by what is stated in the independent claims. Various details of the embodiments are disclosed in the dependent claims and the corresponding figures and description.

[0006] The scope of protection sought by various embodiments of the present disclosure is set out by the independent claims. Embodiments and features described in this specification that do not fall within the scope of the independent claims, if any, are to be construed as examples useful for understanding various embodiments of the present disclosure.

[0007] According to a first aspect, a device is provided, comprising: a component for establishing a connection to a cell using a first radio access technology and a second radio access technology; a component for using at least the first radio access technology to reside on the first cell in an idle mode of a radio resource control (RRC) protocol of the first radio access technology; a component for identifying the first cell as a dynamic spectrum sharing cell in response to receiving signaling information from the first cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; a component for sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; a component for receiving a random access preamble response from the first cell; a component for redirecting to the second cell supporting the second radio access technology based on the random access preamble response; and a component for performing signaling, the signaling being used to convert the device to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0008] According to an embodiment, the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

[0009] According to an embodiment, the apparatus comprises means for performing downlink coarse time and frequency tracking for a second cell based on a signal of the first cell.

[0010] According to an embodiment, the apparatus comprises: means for transitioning from a connected mode to an idle mode; means for performing measurements for the second cell; and means for redirecting the connection to the first cell in response to detecting that the second cell is out of coverage.

[0011] According to an embodiment, the device includes: a component for performing inter-radio access technology measurements between multiple cells supporting at least a first radio access technology and a second radio access technology; a component for detecting the need for handover; and a component for redirecting the connection to a dynamic spectrum sharing cell corresponding to the target cell supporting the second radio access technology and using measurements of the first radio access technology in response to detecting that the target cell for handover supporting the second radio access technology is in an inactive state.

[0012] According to an embodiment, the apparatus comprises means for displaying a first indication on a display of the apparatus in response to identifying the cell as a dynamic spectrum sharing cell, the first indication being used to indicate that a connection to a second cell supporting at least a second radio access technology is available.

[0013] According to an embodiment, the apparatus comprises means for displaying a second indication on a display of the apparatus in response to entering the second cell in connected mode, the second indication being for indicating that a connection to a second cell supporting at least the second radio access technology has been established.

[0014] According to an embodiment, the signaling information comprises information on service-based usage of random access preambles associated with the first radio access technology and the second radio access technology.

[0015] According to an embodiment, the apparatus comprises means for selecting a preamble from the first radio access technology or the second radio access technology based on the type of service being initiated.

[0016] According to an embodiment, the random access preamble response includes timing advance information and downlink timing received from a first cell using a first radio access technology, and the device includes: a component for synchronizing a downlink and an uplink of a second cell using a second radio access technology using the timing advance information and downlink timing of the first cell using the first radio access technology.

[0017] According to an embodiment, the apparatus comprises means for obtaining non-required system information after redirecting to the second cell using the second radio access technology.

[0018] A second aspect relates to a method, comprising: a device, in an idle mode of a radio resource control (RRC) protocol of a first radio access technology, resides in a first cell using at least the first radio access technology, the device comprising a component for establishing a connection to the cell using the first radio access technology and a second radio access technology; in response to receiving signaling information from the first cell, identifying the first cell as a dynamic spectrum sharing cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receiving a random access preamble response from the first cell; redirecting to the second cell supporting the second radio access technology based on the random access preamble response; and performing signaling for converting the device to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0019] According to the third aspect, the device includes at least one processor and at least one memory, the at least one memory having computer program code stored thereon, and the at least one memory and the computer program code are configured to, together with the at least one processor, enable the device to at least perform: in an idle mode of a radio resource control (RRC) protocol of a first radio access technology, reside in a first cell using at least the first radio access technology; in response to receiving signaling information from the first cell, identify the first cell as a dynamic spectrum sharing cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; send a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receive a random access preamble response from the first cell; redirect to the second cell supporting the second radio access technology based on the random access preamble response; and execute signaling for converting the device to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0020] According to the fourth aspect, the device includes: a component for providing a first cell, the first cell is a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the device, and the at least one random access preamble indicates a request to be redirected to a second cell supporting at least a second radio access technology; a component for sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; a component for receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least the second radio access technology; a component for sending an indication of transitioning to an active state to the second cell; and a component for sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to reside on the second cell supporting at least the second radio access technology.

[0021] According to an embodiment, the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

[0022] According to an embodiment, the apparatus comprises: means including means for including one or more of the following in a random access preamble response (RAR) message: - information for redirecting the user equipment to the second cell; - assistance information on uplink timing information to the second cell for the user equipment; -Assistance information about downlink timing; - information about an aperiodic or periodic signal for fine tuning the frequency or time of the second cell; - information about the beam of the second cell relative to the beam of the first cell; - Grant for uplink transmission in the second cell.

[0023] According to an embodiment, the signaling information comprises information on service-based usage of random access preambles associated with the first radio access technology and the second radio access technology.

[0024] According to an embodiment, the apparatus comprises means for configuring the user equipment to perform inter-radio access technology measurements for an intra-radio access technology handover for a target dynamic spectrum sharing cell in which the second radio access technology is not active.

[0025] According to the method of the fifth aspect, it includes: providing a first cell, the first cell is a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in a device for providing the first cell, and at least one random access preamble indicates a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least the second radio access technology; sending an indication to the second cell to transition to an active state; and sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to reside on the second cell supporting at least the second radio access technology.

[0026] According to the sixth aspect, the device includes at least one processor and at least one memory, at least one memory having computer program code stored thereon, and the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the device, and at least one random access preamble indicates a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least the second radio access technology; sending an indication to the second cell to transition to an active state; and sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to reside on the second cell supporting at least the second radio access technology.

[0027] According to the seventh aspect, the device includes: a component for providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble code of the device in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for user equipment to be redirected; a component for configuring the device to operate in an inactive state; a component for receiving an indication of transitioning to an active state from the first cell, the indication being triggered by a random access preamble code received by the first cell from at least one user equipment via the first radio access technology, the random access preamble code indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and a component for performing signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0028] According to an embodiment, the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

[0029] According to an embodiment, the apparatus comprises means for sending downlink broadcast and control information to a user equipment in an active state.

[0030] According to an embodiment, the apparatus comprises: means for starting a timer when the number of user equipments in connected mode of the RRC protocol is zero; and means for configuring the apparatus to transition to an inactive state upon expiration of the timer.

[0031] According to an embodiment, the apparatus comprises means for ceasing to send downlink broadcast and control information to user equipment in an active state.

[0032] According to an embodiment, the apparatus comprises means for notifying a core network of the transition to the inactive state.

[0033] According to an embodiment, the apparatus comprises means for notifying other cells about the transition to the inactive state using the second radio access technology.

[0034] The method according to the eighth aspect includes: providing a second cell by a network element, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble of the network element in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the network element to operate in an inactive state; receiving an indication of transition to an active state from the first cell, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and performing signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0035] According to the ninth aspect, the device includes at least one processor and at least one memory, at least one memory having computer program code stored thereon, and the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble code of the device in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the device to operate in an inactive state; receiving an indication of transitioning to an active state from the first cell, the indication being triggered by a random access preamble code received by the first cell from at least one user equipment via the first radio access technology, the random access preamble code indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and performing signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0036] According to a further aspect, a computer-readable storage medium comprises code for use by an apparatus, which, when executed by a processor, causes the apparatus to perform the above-described method. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] For a more complete understanding of example embodiments, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0038] Figure 1 A schematic block diagram of an apparatus for merging beam distribution arrangements according to an embodiment is shown;

[0039] Figure 2 schematically illustrates a layout of an apparatus according to an example embodiment;

[0040] Figure 3 A portion of an exemplary radio access network is shown;

[0041] Figure 4 An example of a 4G-5G dynamic spectrum sharing (DSS) process is shown;

[0042] Figure 5 A flow chart showing a DSS process performed by a user equipment according to an embodiment;

[0043] Figure 6 shows a flow chart of a DSS process performed by an access point according to an embodiment;

[0044] Figure 7 shows a signaling diagram of a DSS procedure according to various embodiments;

[0045] Figure 8 A flow chart showing a DSS process performed by an access point according to another embodiment;

[0046] Fig. 9 A flow chart illustrating a DSS process performed by a 5G DSS cell according to various embodiments is shown;

[0047] Fig.10 A flow chart showing a DSS process performed by a 6G DSS cell according to various embodiments; and

[0048] Fig.11 A flow chart of a DSS process performed by a 6G UE according to various embodiments is shown. DETAILED DESCRIPTION

[0049] Suitable means and possible mechanisms for supplementing the Dynamic Spectrum Sharing (DSS) process are described in more detail below. Although the following focuses on 4G, 5G and 6G networks, the embodiments further described below are by no means limited to implementation only in said networks, but they are applicable to any network supporting DSS.

[0050] In this regard, first refer to Figure 1 and Figure 2 ,in Figure 1A schematic block diagram of an exemplary apparatus or electronic device 50 is shown which may incorporate arrangements according to embodiments. Figure 2 The layout of the device according to the exemplary embodiment is shown. Figure 1 and 2 components.

[0051] The electronic device 50 may be, for example, a mobile terminal or user equipment of a wireless communication system. The device 50 may include a housing 30 for accommodating and protecting the device. The device 50 may also include a display 32 and a keypad 34. Instead of a keypad, the user interface may be implemented as a virtual keyboard or a data entry system as part of a touch-sensitive display.

[0052] The device may include a microphone 36 or any suitable audio input that may be a digital or analog signal input. The device 50 may further include an audio output device, such as headphones 38, a speaker, or any of an analog audio or digital audio output connection. The device 50 may also include a battery 40 (or the device may be powered by any suitable mobile energy device, such as a solar cell, a fuel cell, or a clock generator). The device may also include a camera 42 capable of recording or capturing images and / or video. The device 50 may also include an infrared port 41 for short-range line-of-sight communication with other devices. In other embodiments, the device 50 may also include any suitable short-range communication solution, such as, for example, a Bluetooth wireless connection or a USB / Firewire wired connection.

[0053] The device 50 may include a controller 56 or processor for controlling the device 50. The controller 56 may be connected to a memory 58, which may store both user data and instructions for implementation on the controller 56. The memory may be a random access memory (RAM) and / or a read-only memory (ROM). The memory may store computer-readable, computer-executable software including instructions that, when executed, cause the controller / processor to perform the various functions described herein. In some cases, the software may not be directly executed by the processor, but may cause the computer (e.g., when compiled and executed) to perform the functions described herein. The controller 56 may be further connected to a codec circuit 54, which is suitable for performing the coding and decoding of audio and / or video data or assisting the coding and decoding performed by the controller.

[0054] The device 50 may include a radio interface circuit 52 connected to the controller and adapted to generate wireless communication signals, for example for communication with a cellular communication network, a wireless communication system or a wireless local area network. The device 50 may also include an antenna 44 connected to the radio interface circuit 52 for transmitting radio frequency signals generated at the radio interface circuit 52 to other devices and for receiving radio frequency signals from other devices.

[0055] In the following, as an example of an access architecture to which the embodiments may be applied, a radio access technology (RAT) based on long term evolution advanced (LTE Advanced, LTE-A) or new radio (NR, 5G) will be used to describe different exemplary embodiments without limiting the embodiments to such architectures. It will be appreciated by those skilled in the art that the embodiments may also be applied to other types of communication networks with suitable devices by appropriately adjusting parameters and processes. Some examples of other options for suitable systems are universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, the same as E-UTRA), wireless local area network (WLAN or WiFi), world wide interoperability for microwave access (Wi MAX), personal communications service (PCS), wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad hoc networks (MANETs), and Internet Protocol Multimedia Subsystems (IMS) or any combination thereof.

[0056] Figure 3 An example of a simplified system architecture is depicted, showing only some elements and functional entities, all of which are logical components, the implementation of which may differ from what is shown. Figure 3 The connections shown in are logical connections; the actual physical connections may be different. It is obvious to those skilled in the art that a system typically includes Figure 3 Other functions and structures than those shown. However, the embodiments are not limited to the systems given as examples, but a person skilled in the art may apply the solution to other communication systems having the necessary properties.

[0057] Figure 3 The example of FIG. 1 shows a portion of an exemplary radio access network.

[0058] Figure 3 Shown is a user equipment 300 and 302 configured to be wirelessly connected to an access node (such as (e / g) Node B) 304 providing the cell on one or more communication channels in the cell. The physical link from the user equipment to the (e / g) Node B is called an uplink or reverse link, and the physical link from the (e / g) Node B to the user equipment is called a downlink or forward link. It should be understood that the (e / g) Node B or its functions can be implemented by using any node, host, server or access point entity suitable for such use.

[0059] The communication system usually includes more than one (e / g) node B, in which case the (e / g) node B can also be configured to communicate with each other through links designed for the purpose, wired or wireless. These links can be used for signaling purposes. (e / g) Node B is a computing device configured to control the radio resources of the communication system to which it is coupled. Node B can also be referred to as a base station, an access point or any other type of interface device, including a relay station capable of operating in a wireless environment. (e / g) Node B includes or is coupled to a transceiver. A connection is provided from the transceiver of the (e / g) node B to an antenna component, which establishes a bidirectional radio link to a user equipment. The antenna component may include multiple antennas or antenna elements. (e / g) Node B is also connected to a core network 310 (CN or next generation core network NGC). Depending on the system, the counterpart on the CN side may be a service gateway (S-GW, routing and forwarding user data packets), a packet data network gateway (P-GW), which is used to provide a connection of a user equipment (UE) to an external packet data network or a mobile management entity (MME), etc. CN may include a network entity or node that may be referred to as a management entity. Examples of network entities include at least an Access and Mobility Management Function (AMF).

[0060] A user equipment (also referred to as user equipment (UE), user terminal, terminal device, wireless device, mobile station (MS), etc.) shows a type of device where resources on the air interface are allocated and assigned, so any features described here by the user equipment can be implemented using corresponding network devices, such as relay nodes, eNBs and gNBs. An example of such a relay node is a layer 3 relay (self-backhaul relay) towards a base station.

[0061] User equipment generally refers to portable computing devices including wireless mobile communication devices operating with or without a subscriber identity module (SIM), including but not limited to the following types of devices: mobile stations (mobile phones), smart phones, personal digital assistants (PDAs), mobile phones, devices using wireless modems (alarms or measuring devices, etc.), laptop computers and / or touch screen computers, tablet computers, game consoles, notebooks, and multimedia devices. It should be understood that user equipment can also be almost the only uplink-only device, an example of which is a camera or video camera that loads images or video clips to the network. The user device can also be a device with the ability to operate in an Internet of Things (IoT) network, which is a scenario in which an object is provided with the ability to transmit data over a network without human-to-human or human-to-computer interaction. Therefore, the user device can be an IoT device. The user device can also utilize the cloud. In some applications, the user device may include a small portable device with a radio component (such as a watch, headphones, or glasses), and performs calculations in the cloud. The user device (or in some embodiments, a layer 3 relay node) is configured to perform one or more of the user device functions. A user device may also be called a subscriber element, a mobile station, a remote terminal, an access terminal, a user terminal, or User Equipment (UE), just to name a few names or devices.

[0062] The various techniques described herein may also be applied to cyber-physical systems (CPS) (systems where cooperating computing elements control physical entities). CPS may enable the implementation and utilization of a large number of interconnected ICT devices (sensors, actuators, processor microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber-physical systems, where the physical systems in question have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

[0063] Additionally, although the apparatus has been depicted as a single entity, different components, processors and / or memory components may be implemented ( Figure 1 not shown).

[0064] 5G enables the use of Multiple Input Multiple Output (MIMO) antennas, more base stations or nodes compared to LTE (the so-called small cell concept), including macro sites operating in coordinated operation with smaller stations and depending on service requirements, use cases and / or spectrum availability. The access nodes of the radio network form a transmit / receive (TX / Rx) point (TRP) and it is expected that UEs access a network of at least partially overlapping multiple TRPs (such as macro cells, small cells, pico cells, femto cells, remote radio heads, relay nodes, etc.). The access nodes may be equipped with massive MIMO antennas, i.e. very large antenna arrays consisting of, for example, hundreds of antenna elements, implemented in a single antenna panel or in multiple antenna panels, capable of using multiple simultaneous radio beams to communicate with the UE. A UE may be provided with a MIMO antenna with an antenna array consisting of, for example, dozens of antenna elements implemented in a single antenna panel or in multiple antenna panels. Therefore, the UE can use one beam to access one TRP, use multiple beams to access one TRP, use one (common) beam to access multiple TRPs, or use multiple beams to access multiple TRPs.

[0065] 4G / LTE networks support some multi-TRP schemes, but in 5G NR, the multi-TRP feature is enhanced, for example, via the transmission of multiple control signals via multiple TRPs, which enables improved link diversity gain. In addition, high carrier frequencies (e.g., mmWave) together with massive MIMO antennas require new beam management processes for multi-TRP technology.

[0066] 5G mobile communications support a wide range of use cases and related applications including video streaming. Augmented reality is a different way of data sharing and various forms of machine-type applications (such as (massive) machine-type communications (mMTC), including vehicle safety, different sensors and real-time control. 5G is expected to have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and can also be integrated with existing traditional radio access technologies (such as LTE). The integration with LTE can be implemented as a system at least in the early stages, where macro coverage is provided by LTE and 5G radio interface access comes from small cells by aggregation to LTE. In other words, 5G is planned to support inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz-cmWave, below 6GHz-cmWave-mmWave). One of the concepts considered to be used in 5G networks is network slicing, in which multiple independent and dedicated virtual subnetworks (network instances) can be created within the same infrastructure to run services with different requirements for latency, reliability, throughput and mobility.

[0067] The frequency bands for 5G NR are divided into two frequency ranges: Frequency Range 1 (FR1), which includes the bands below 6 GHz, i.e. the bands traditionally used by the previous standard, and also includes new bands extended to cover potential new spectrum supply from 410 MHz to 7125 MHz, and Frequency Range 2 (FR2), which includes the bands from 24.25 GHz to 52.6 GHz. FR2 therefore includes bands in the mmWave range, which, due to their shorter range and higher available bandwidth, require a slightly different approach in radio resource management compared to bands in FR1.

[0068] The current architecture in LTE networks is completely distributed in the radio and completely concentrated in the core network. Low-latency applications and services in 5G require content to be close to the radio, which leads to local interruptions and multi-access edge computing (MEC). 5G enables analysis and knowledge generation to occur at the data source. This approach requires the use of resources that may be discontinuously connected to networks such as laptops, smart phones, tablet computers, and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response times. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer self-organizing networking and processing, which can also be classified as local cloud / fog computing and grid / grid computing, dew computing, mobile edge computing, micro-cloud, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (large-scale connectivity and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analysis, time-critical control, healthcare applications).

[0069] The communication system may also be able to communicate with or utilize services provided by other networks, such as the public switched telephone network or the Internet 312. The communication network may also be able to support the use of cloud services, for example, at least a portion of the core network operations may be performed as a cloud service (this is in the Figure 3 314). The communication system may also include a central control entity or the like, providing facilities for networks of different operators to collaborate, for example in spectrum sharing.

[0070] Edge cloud can be brought into the radio access network (RAN) by leveraging network function virtualization (NFV) and software defined networking (SDN). Using edge cloud can mean performing access node operations at least partially in a server, host or node operably coupled to a remote radio head or base station including the radio part. Node operations may also be distributed among multiple servers, nodes or hosts. The application of cloud RAN architecture enables RAN real-time functions to be performed on the RAN side (in distributed components, DU), while non-real-time functions are performed in a centralized manner (in centralized components CU308).

[0071] It should also be understood that the labor distribution between core network operations and base station operations may be different from LTE or even non-existent. Some other technological advances that may be used are big data and all-IP, which can change the way networks are being built and managed. 5G (or New Radio) NR networks are being designed to support multiple layers, where MEC servers can be placed between the core and the base station or Node B (gNB). It should be understood that MEC can also be applied in 4G networks. gNB is the next generation Node B (or new Node B) that supports 5G networks (i.e., NR).

[0072] 5G can also utilize non-ground nodes 306. For example, by providing backhaul, wireless access to wireless devices, service continuity for machine-to-machine (M2M) communications, service continuity for Internet of Things (IoT) devices, service continuity for passengers on board of transportation vehicles, ensuring service availability for critical communications, and / or ensuring service availability for future railway / maritime / aircraft communications, to enhance or supplement the coverage of 5G services. Non-ground nodes can have a fixed position relative to the surface of the earth, or non-ground nodes can be mobile non-ground nodes that can move relative to the surface of the earth. Non-ground nodes can include satellites and / or HAPS. Satellite communications can utilize geostationary earth orbit (GEO) satellite systems, but can also utilize low earth orbit (LEO) satellite systems, especially large constellations (systems that deploy hundreds of (nano) satellites). Each satellite in a large constellation can cover several satellite-supporting network entities that create a cell on the ground. A cell on the ground can be created by a relay node 304 on the ground or by a gNB located on the ground or in a satellite.

[0073] Those skilled in the art understand that the depicted system is only an example of a part of a radio access system, and in practice, the system may include multiple (e / g) Node Bs, the user equipment may have access to multiple radio cells, and the system may also include other devices, such as physical layer relay nodes or other network elements. At least one of the (e / g) Node Bs may be a home (e / g) Node B. In addition, in the geographical area of ​​the radio communication system, a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided. A radio cell may be a macro cell (or umbrella cell), which is a large cell, typically having a diameter of up to tens of kilometers, or a smaller cell, such as a micro cell, a femto cell or a pico cell. Figure 1 The (e / g) Node Bs can provide any kind of these cells. A cellular radio system can be implemented as a multi-layer network including several kinds of cells. Typically, in a multi-layer network, one access node provides a cell or cells, so multiple (e / g) Node Bs are needed to provide this network structure.

[0074] In order to meet the needs of improving the deployment and performance of communication systems, the concept of "plug and play" (e / g) Node B is introduced. Generally, in addition to the home (e / g) Node B (H(e / g) Node B), the network that can use the "plug and play" (e / g) Node B includes a home node B gateway or HNB-GW ( Figure 1 The HNB gateway (HNB-GW) usually installed in the operator's network can aggregate services from a large number of HNBs back to the core network.

[0075] The Radio Resource Control (RRC) protocol is used in various wireless communication systems to define the air interface between the UE and the base station (such as eNB / gNB). The protocol is specified by 3GPP in TS36.331 for LTE and TS38.331 for 5G. In RRC, the UE can operate in idle mode or in connected mode in LTE and in 5G, where the radio resources available to the UE depend on the mode in which the UE is currently located. In 5G, the UE can also operate in inactive mode. In RRC idle mode, the UE has no connection for communication, but the UE is able to listen to paging messages. The UE can communicate with the eNB / gNB via various logical channels (e.g., broadcast control channel (BCCH), paging control channel (PCCH), common control channel (CCCH), dedicated control channel (DCCH), dedicated traffic channel (DTCH)).

[0076] The transitions between states are controlled by the state machine of RRC. When the UE is powered on, it is in disconnected mode / idle mode. The UE can transition to RRC connected mode by initial attach or connection establishment. If there is no activity from the UE for a short period of time, the eNB / gNB can suspend its session by moving to RRC inactive mode and can resume its session by moving to RRC connected mode. The UE can move to RRC idle mode from RRC connected mode or from RRC inactive mode.

[0077] The actual user and control data from the network to the UE is sent via downlink physical channels, which in 5G include the Physical Downlink Control Channel (PDCCH) carrying the necessary downlink control information (DCI), the Physical Downlink Shared Channel (PDSCH) carrying user data and user system information, and the Physical Broadcast Channel (PBCH) carrying the necessary system information to enable the UE to access the 5G network.

[0078] User and control data from the UE to the network are sent via uplink physical channels, which in 5G include a physical uplink control channel (PUCCH) for uplink control information including HARQ feedback acknowledgment for link adaptation, scheduling requests and downlink channel state information, a physical uplink shared channel (PUSCH) for uplink data transmission, and a physical random access channel (PRACH) used by the UE to request connection establishment, known as random access.

[0079] Throughout the history of 3GPP networks, there has been an ongoing migration towards the next generation of radio access technologies (RATs). This has challenged network operators regarding their decisions about when and to what extent to invest in the next generation of RATs. Dynamic spectrum sharing (DSS) was introduced in 3GPP Release 15 to provide a migration path from LTE to NR by allowing LTE and NR to share the same carrier. Thus, as the market penetration of NR devices increases, DSS allows resources (i.e. frequencies) to be gradually dedicated to the new air interface.

[0080] In the initial phase of deploying a new RAT, network operators tend to prioritize the coverage of the new RAT, at least for advertising and marketing purposes. For example, operators initially deploy LTE-NR DSS on low-bands to be able to claim extended 5G coverage. These low-bands may be used as fallback bands for NR devices due to coverage challenges in other bands, and most operators have limited low-band spectrum, which may not be enough to provide separate resources for LTE and NR respectively. The introduction of DSS is at least to address this problem.

[0081] When the market penetration of NR UE is low, it means that most users are using LTE devices, so the activation of 5G on the cell should introduce minimal overhead. As the penetration of NR UE increases, more capacity will be required, so sharing for 4G-5G in these low frequency bands will require efficient sharing mechanisms.

[0082] Figure 4 An example of an LTE-NR DSS procedure is shown. At the beginning, a 4G cell with dynamic spectrum sharing (DSS) capability (i.e., a 4G DSS cell) is in normal operation mode, where 4G primary and secondary synchronization signals (PSS / SSS) and various master information blocks (MIBs) and system information blocks (SIBs) are broadcast.

[0083] At least part of the same geographical area covered by a 4G DSS cell may also be covered by a 5G DSS cell. The 5G resources of a 5G DSS cell may be provided by the same or at least partly different NBs as those used for a 4G DSS cell. In a typical DSS scenario, 4G and 5G resources are provided by a common radio unit. The same or alternatively different baseband components may be used for the 4G and 5G resources.

[0084] A 5G-capable UE can initially camp on a 5G DSS cell. In order for any 5G-capable UE to camp on a 5G DSS cell in RRC idle mode, the 5G DSS cell must be active, which means that one or more cells periodically broadcast synchronization signals (PSS / SSS), MIB, SIB, various paging messages, etc. The 5G DSS cell reserves some RACH preamble resources for 5G UEs and broadcasts them to the UEs. Based on the information broadcast by the 5G DSS cell, the UE identifies the cell as a 5G DSS cell. The UE can display a 5G icon or any other type of indication to indicate to the user that a 5G connection can be established in the cell.

[0085] The UE then performs an RRC establishment procedure by sending at least one of the RACH preambles to the 5G DSS cell, which responds to a RACH preamble response (RAR) message, after which the transition to RRC connected mode can be completed. Thereafter, the 4G and 5G schedulers can initiate resource sharing beyond the default original reserved resources for each radio access technology.

[0086] However, the fact that 5G DSS cells must continuously transmit downlink (DL) signals (including synchronization, SIB, and MIB) in the absence of any 5G-capable UEs in their area inevitably reduces the available radio resource capacity for 4G connections. Especially during the early stages of 5G deployment, there are usually only a few or even no 5G-capable UEs. However, even if there are no 5G-capable UEs, 5G DSS cells provide continuous overhead in the DSS cells. This reduces the performance perceived by 4G UEs and generates additional power consumption due to DL transmissions.

[0087] Therefore, there is a need for a method by which the legacy RAT can be operated with minimal overhead and also enable the cell to be used in DSS mode in the presence of new RAT users.

[0088] In the following, according to various embodiments, enhanced methods for achieving more spectrally and energy efficient usage of spectrum resources of DSS will be described in more detail.

[0089] exist Figure 5 A method for reflecting the operation of a terminal device, such as a user equipment (UE), disclosed in a flowchart, wherein the device includes: a component for establishing a connection to a cell using a first radio access technology and a second radio access technology; wherein the method includes: using at least the first radio access technology to camp (500) on a first cell in an idle mode of a radio resource control (RRC) protocol of the first radio access technology; in response to receiving signaling information from the first cell, identifying (502) the first cell as a dynamic spectrum sharing cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; sending (504) a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receiving (506) a random access preamble response from the first cell; redirecting (508) to the second cell supporting the second radio access technology based on the random access preamble response; and performing (520) signaling, the signaling being used to convert the device to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0090] The method may also be described as reflecting the operation of a network element such as an access node (e.g., a gNB), such as Figure 6As shown in a flowchart, the network element includes a device for providing a first cellular cell, the first cellular cell is a dynamic spectrum sharing cellular cell supporting at least a first radio access technology, wherein at least one random access preamble code indicating a request to be redirected to a second cellular cell supporting at least a second radio access technology is stored in the network element, wherein the method includes sending (600) signaling information to a user equipment, wherein the signaling information includes information for establishing a connection to the second cell; receiving (602) a random access preamble code from the user equipment via the first radio access technology, the random access preamble code indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; sending (604) an indication to transition to an active state to the second cell; and sending (606) a random access preamble code response to the user equipment via the first radio access technology, wherein the random access preamble code response includes signaling for redirecting the user equipment to reside on the second cell supporting at least the second radio access technology.

[0091] In the following, the method and related embodiments are described for description and simplification purposes by referring to 5G / NR RAT as the first radio access technology and 6G RAT as the second radio access technology. However, it should be noted that the method and related embodiments are not limited to dynamic spectrum sharing between 5G and 6G RAT, but can be applied between any RAT (e.g., 4G and 6G RAT).

[0092] Here, the terms "a first cell supporting a first radio access technology" or "5G DSS cell" and "a second cell supporting a second radio access technology" or "6G DSS cell" are used to refer to different radio interfaces and control protocols of different RATs, respectively. However, as described above, in a typical DSS case, a 5G DSS cell and a 6G DSS cell may share common radio components. The same or alternatively different baseband components may be used for a 5G DSS cell and a 6G DSS cell.

[0093] Therefore, these methods and related embodiments enable 5G-6G DSS to be performed in a significantly reduced overhead and energy-efficient manner, wherein the 6G DSS cell only sends downlink (DL) signals (including synchronization signals and MIB) when there is a connected user equipment, or at least when there has been a connected user equipment on the 6G DSS cell in the recent past. Otherwise, the 5G DSS cell announces the existence of the 6G DSS cell and provides the UE with the minimum system information required to reside on the 6G cell, for example via a 5G system information message. When the UE switches to RRC connected mode, the 5G cell redirects the 6G-capable UE to the 6G DSS cell, for example by using a random access preamble response (RAR) message. The 5G DSS cell sends an indication of transitioning to an active state to the 6G DSS cell so that the necessary signaling required to transition the 6G-capable UE to the connected mode of the 6G RRC can be performed. It should be noted that redirecting the UE to a 6G DSS cell via RAR is feasible because most of the information on the 6G DSS cell configuration can be conveyed via system information messages and thus the size of the MAC Control Element (MAC CE) for RAR remains modest.

[0094] Figure 7 The signaling diagram of shows an exemplary high-level description of the method and some related embodiments between a 6G UE, a 5G DSS cell and a 6G DSS cell. Here, it is assumed that the UE has registered with the 5G core network and the 6G core network, and the 6G core network is aware of the dynamic spectrum sharing cell and its status, that is, either active (that is, the dynamic spectrum sharing cell is able to send paging resources) or inactive. The 6G core network can also forward paging messages to both the 5G cell and the 6G cell, for example, for high priority paging.

[0095] At the beginning, the 6G DSS cell remains in an inactive state (700). Therefore, the 6G DSS cell initially reserves no DL resources for 6G, for example, no PSS / SSS or MIB / SIB transmissions are performed. As part of its DSS operation, the 5G DSS cell reserves some RACH preamble resources for 6G UEs (702). It should be noted that no other 6G UL resources need to be reserved.

[0096] Since the 6G DSS cell is in an inactive state, the 5G DSS cell announces the existence of the 6G DSS cell. Therefore, the 5G DSS cell provides broadcast information to the UE (704), which includes at least the minimum information required to establish an RRC connection with the 6G DSS cell. The 5G DSS cell broadcast information may include information about a dedicated RACH preamble for the 6G DSS cell, which may share the same RACH timing with the 5G DSS cell. The broadcast information may also include, for example, a 6G cell MIB, which may indicate the status of the 6G DSS cell, so if the 6G DSS cell is active, the UE does not have to continuously monitor via synchronization signals. Therefore, the power consumption of the UE is reduced, thereby saving battery life.

[0097] At some point, the 6G-capable UE camps on a 5G DSS cell in 5G RRC idle mode (706). Based on the 5G DSS cell broadcast information, the UE identifies the cell as a DSS cell.

[0098] According to an embodiment, an apparatus such as a UE comprises means for displaying a first indication on a display of the apparatus in response to identifying the cell as a dynamic spectrum sharing cell, the first indication being used to indicate that connection to at least the second cell supporting a second radio access technology is available.

[0099] Thus, the UE may display a first type of 6G icon or any other type of indication on its display (708), showing the user in the cell that a 6G connection is possible in the component. The UE may then, for example as a default setting or intentional selection by the user, begin preparations for establishing a connection to the 6G DSS cell. Thus, of the RACH preambles received in the 5G DSS cell broadcast information, the UE selects at least one RACH preamble dedicated to the 6G DSS cell and sends it to the 5G DSS cell (710). When the 5G DSS cell detects the preamble dedicated to the 6G DSS cell, the 5G DSS cell notifies the 6G DSS cell that it needs to switch to active mode (712). The 6G DSS cell then switches to active mode (714) and begins preparations for reserving 6G DL / UL resources. The 5G DSS cell responds to the RACH preamble dedicated to the 6G DSS cell received from the UE with a random access preamble response (RAR) message (716).

[0100] According to an embodiment, a network element such as a gNB comprises means for including one or more of the following in a Random Access Preamble Response (RAR) message: - information for redirecting the user equipment to the second cell; -Assistance information on uplink timing information for user equipment; -Assistance information about downlink timing; - information about an aperiodic or periodic signal for fine tuning the frequency or time of the second cell; - information about the beam of the second cell relative to the beam of the first cell; - Grant for uplink transmission in the second cell.

[0101] Therefore, the RAR message may additionally include information to help the UE acquire faster DL synchronization and beam capture with the 6G DSS cell. The uplink timing information for the UE may include, for example, the UL timing advance to the 6G DSS cell. The auxiliary information about the downlink timing may include, for example, the offset between the 5G and 6G cell timing.

[0102] After the 6G DSS cell transitions to active mode (714), 6G DL / UL resources are reserved and transmitted on the 6G DSS cell as needed (718). In this article, the 6G DSS cell can send a control signal to the UE based on the previously transmitted aperiodic or periodic signal to perform fine tuning of time and frequency on the 6G cell.

[0103] According to one embodiment, a device such as a UE includes a device for performing downlink coarse time and frequency tracking for a second cell based on a signal of a first cell. Thus, the UE can perform DL coarse time and frequency tracking for a 6G cell based on a 5G cell signal (e.g., SSB or other reference symbols).

[0104] After obtaining sufficient information, the UE completes the RRC establishment procedure and enters connected mode in the 6G DSS cell (720).

[0105] According to an embodiment, an apparatus such as a UE comprises means for displaying a second indication on a display of the apparatus in response to entering the second cell in connected mode, the second indication indicating that a connection has been established to a second cell supporting at least a second radio access technology.

[0106] Thus, the UE may display a second type of 6G icon or any other type of indication on its display, which indicates that the UE is now using a 6G connection.

[0107] According to an embodiment, an apparatus such as a UE comprises: means for transitioning from a connected mode to an idle mode; means for performing measurements for a second cell; and means for redirecting a connection to a first cell in response to detecting that the second cell is out of coverage.

[0108] Therefore, at some point, the UE may not need to remain in RRC connected mode and it transitions to RRC idle mode. However, a UE in idle mode on a 6G DSS cell will perform measurements of the cell and monitor paging as per normal idle mode procedures. If the UE measurements show that the 6G DSS cell is out of coverage, the UE falls back to the 5G DSS cell.

[0109] According to an embodiment, an apparatus such as a UE includes: a component for performing radio access technology (I-RAT) measurements between multiple cells supporting at least a first radio access technology and / or a second radio access technology; a component for detecting the need for switching; and a component for redirecting a connection to a dynamic spectrum sharing component corresponding to the target cell and using the first radio access technology in response to detecting that the target cell for switching supporting the second radio access technology is in an inactive state.

[0110] A process for UE mobility may also be employed so that a 6G DSS neighboring cell may remain in an inactive state (no DL transmission). The UE may perform I-RAT measurements on neighboring 6G DSS cells, and when it notices that the target 6G DSS cell for handover is in an inactive state, it seeks the corresponding 5G DSS cell and starts the above process to wake up the target cell to an active state. The 6G DSS cell may return to an inactive state when all 6G UEs exit the 6G DSS cell and do not have any RRC transactions for a configured time period.

[0111] The operation of access nodes such as gNBs can also be evaluated from the perspective of providing 6G DSS cell operations. As mentioned above, in a typical DSS case, the same network element (such as an access point, i.e., a gNB) can provide radio resources for both 5G DSS cells and 6G DSS cells.

[0112] The method may be described as reflecting the operation of a network element such as an access node (e.g., a gNB), such as Figure 8As shown in the flowchart, the method includes providing (800) a second cell by a network element, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble code of a device in a first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the device (802) to operate in an inactive state; receiving (804) an indication of transition to an active state from the first cell, the indication being triggered by a random access preamble code received by the first cell from at least one user equipment via the first radio access technology, the random access preamble code indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and executing (806) signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0113] The method and related embodiments may provide significant advantages. A larger number of frequency bands may be allocated to the DSS without the risk of increasing overhead. Since the 6G DSS cell does not send additional downlink signals (6G control signals) when a 6G UE is in its area, but instead uses traditional RAT (e.g., 5G) resources, power consumption savings of 6G DSS cell network components and 6G UEs may be achieved. In addition, this also helps to reduce interference in the system, which is particularly important for dense deployments where most operator traffic is located. On the other hand, timer-based 6G DSS cell activation allows 6G DSS cells to be longer in areas where lower latency or RRC inactive UEs are to be supported.

[0114] exist Fig. 9 Some of the above-described embodiments relating to the operation of a cell supporting at least a first radio access technology (i.e., a 5G DSS cell in this example) are shown in a flowchart of FIG.

[0115] The 5G DSS cell receives an indication that the 6G DSS cell is in an inactive state (900), that is, the 6G DSS cell does not send any DL control signals and only needs to reserve some RACH resources in the UL. The 5G DSS cell reserves one or more RACH preambles to be dedicated to the 6G DSS cell (902). Broadcast by the 5G DSS cell to UEs in its area. The RACH resources reserved for the 6G DSS cell can share the same RACH timing with the 5G DSS cell. If the 5G DSS cell detects a preamble dedicated to the 6G DSS cell sent by the UE (904), the 5G DSS cell notifies the 6G DSS cell that it needs to switch to active mode (906). The 5G DSS cell also responds to the RACH preamble of the 6G UE with a RAR message (908), which may include information for redirecting the UE to the 6G DSS cell, as well as various auxiliary information items as described above for assisting the UE in capturing faster DL synchronization and beam capture using the 6G DSS cell. When the 6G DSS cell initiates a transition to active mode, the 5G DSS cell may be instructed to reserve UL and DL resources for the 6G DSS cell (910). If the 5G DSS cell receives a notification from the 6G DSS cell that it has transitioned to an inactive state (912), the 5G DSS cell may release any 6G DSS resources reserved for the 6G DSS cell in the active state and continue to reserve only the resources required for the 6G DSS cell in the inactive state (900).

[0116] exist Fig.10 Some of the above-described embodiments related to the operation of a cell supporting at least a second radio access technology (ie, a 6G DSS cell in this example) are shown in a flowchart of FIG.

[0117] Again, the 6G DSS cell is initially in an inactive state (1000) and notifies the core network and other neighboring 6G / 5G cells of this state. If the 6G DSS cell receives an indication from the 5G DSS cell that the 5G DSS cell has detected a preamble dedicated to the 6G DSS cell sent by the UE (1002), the 6G DSS cell initiates its transition to an active state (1004).

[0118] It should be noted that the indication from the 5G DSS cell may also include additional information about the UE triggering the transition to the active state, such as: - Information about UE capabilities for handover scenarios; -5G DSS cell beam related information, such as the UL beam used for the RACH process; -Timing advance information provided by the 5G DSS cell to the UE; - Information on the type of RACH triggered by a 6G UE in a 5G DSS cell. If the RACH resources are further divided for different slices or services or UE capabilities, the 6G DSS cell can use this information to handle the UE appropriately; - Information about periodic or aperiodic frequency / timing fine-tuning information provided to the UE; - Information about the UL grant will be used by the UE to continue the RRC connection procedure. Note that after the UE has acquired synchronization with the 6G DSS cell, the 6G DSS cell may instead decide to provide the UL grant via a separate DL transmission in the 6G DSS cell.

[0119] The 6G DSS cell may also notify the core network that it has transitioned to the active state (1004) so ​​that the core network can page the UE in the correct RAT. For mobility purposes, other neighboring 5G and 6G cells may also be notified of the transition of the 6G DSS cell to the active state. During the transition period to the active state, the 6G DSS cell will reserve resources for UL and DL (1006). This may include at least resources for control signaling in UL and DL. The 6G DSS cell may transmit specific non-periodic or periodic control signals (1008) to achieve faster UE synchronization to the 6G DSS cell. Once the 6G DSS component enters the active state (1010), it proceeds according to the 6G process.

[0120] The 6G DSS cell may continuously monitor the number of UEs in RRC connected mode in the 6G DSS cell. Once there are no remaining UEs in RRC connected mode in the 6G DSS cell (1012), the 6G DSS cell may start an inactive timer (1014). The parameters of the timer may be set via O&M parameters or via a machine learning algorithm. When the timer (1016) expires, the 6G DSS cell may transition back to an inactive state (1018).

[0121] It should be noted that for intra-6G mobility purposes, a 6G UE may be instructed to perform I-RAT measurements of a 5G DSS cell with a 6GDSS reserved preamble, as described above. Thus, RACH and RAR for the handover procedure may be performed on the 5G DSS cell in the same manner as for the RRC idle to RRC connected mode transition described above.

[0122] exist Fig.11 Some of the above-mentioned embodiments related to the operation of 6G UE are shown in the flowchart.

[0123] Again, assuming that the 6G DSS cell is inactive, the UE scans and selects a 5G DSS cell (1100). When obtaining the 5G DSS cell system information message, the UE learns that the 5G cell is a DSS cell and that it shares resources with the 6G cell (1102). The UE also obtains the minimum system information required to establish an RRC connection with the 6G cell (1104). The UE may also display a 6G flag indicating that it can access the 6G RAT (1106). When the UE needs to initiate a random access procedure (1108), the UE may decide to use a 6G dedicated preamble (1110). The 5G DSS cell may respond to the preamble with a traditional 5G RAR message (1112), so the UE performs an RRC establishment procedure in the 5G DSS cell (1114).

[0124] If the 5G DSS cell responds to the preamble with a redirection to the 6G DSS cell (1112), the UE should use the information obtained via the SIB to continue the RRC establishment process in the 6G DSS cell (1116). The UE may need to perform fine frequency and time acquisition of the 6G DSS cell (1118) before completing the RRC establishment process (1120). Once the UE's RRC connection is released (1122), the UE can receive information on the 6G DSS cell non-inactive timer, such as an estimate of the minimum time that the 6G DSS cell can remain in an active state. When the 6G DSS is in an active state, the UE can perform an idle mode process on the 6G DSS cell (1124). When the 6G DSS cell enters an inactive state (1126), the UE will revert to the corresponding 5G DSS cell (1128).

[0125] According to one aspect, an apparatus (such as a UE) includes: a component for establishing a connection to a cell using a first radio access technology and a second radio access technology; a component for using at least the first radio access technology to reside on the first cell in an idle mode of a radio resource control (RRC) protocol of the first radio access technology; a component for identifying the first cell as a dynamic spectrum sharing cell in response to receiving signaling information from the first cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; a component for sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; a component for receiving a random access preamble response from the first cell; a component for redirecting to the second cell supporting the second radio access technology based on the random access preamble response; and a component for performing signaling, the signaling being used to convert the apparatus to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0126] According to an embodiment, the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

[0127] According to an embodiment, the apparatus comprises means for performing downlink coarse time and frequency tracking for a second cell based on a signal of the first cell.

[0128] According to an embodiment, the apparatus comprises: means for transitioning from a connected mode to an idle mode; means for performing measurements for the second cell; and means for redirecting the connection to the first cell in response to detecting that the second cell is out of coverage.

[0129] According to an embodiment, the apparatus includes: a component for performing inter-radio access technology measurements between multiple cells supporting at least a first radio access technology and a second radio access technology; a component for detecting the need for switching; and a component for redirecting a connection to a dynamic spectrum sharing cell corresponding to a target cell supporting the second radio access technology and using measurements of the first radio access technology in response to detecting that a target cell for switching supporting the second radio access technology is in an inactive state.

[0130] According to an embodiment, the apparatus comprises means for displaying a first indication on a display of the apparatus in response to identifying the cell as a dynamic spectrum sharing cell, the first indication being used to indicate that a connection to a second cell supporting at least a second radio access technology is available.

[0131] According to an embodiment, the apparatus comprises means for displaying a second indication on a display of the apparatus in response to entering the second cell in connected mode, the second indication being for indicating that a connection to a second cell supporting at least the second radio access technology has been established.

[0132] According to an embodiment, the signaling information comprises information on service-based usage of random access preambles associated with the first radio access technology and the second radio access technology.

[0133] According to an embodiment, the apparatus comprises means for selecting a preamble from the first radio access technology or the second radio access technology based on the type of service being initiated.

[0134] According to an embodiment, the random access preamble response includes timing advance information and downlink timing received from a first cell using a first radio access technology, and the device includes: a component for synchronizing a downlink and an uplink of a second cell using a second radio access technology using the timing advance information and downlink timing of the first cell using the first radio access technology.

[0135] According to an embodiment, the apparatus comprises means for obtaining non-required system information after redirecting to the second cell using the second radio access technology.

[0136] According to another aspect, the device includes at least one processor and at least one memory, the at least one memory having computer program code stored thereon, and the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: in an idle mode of a radio resource control (RRC) protocol of a first radio access technology, reside in a first cell using at least the first radio access technology; in response to receiving signaling information from the first cell, identify the first cell as a dynamic spectrum sharing cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; send a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receive a random access preamble response from the first cell; redirect to the second cell supporting the second radio access technology based on the random access preamble response; and perform signaling for converting the device to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0137] Such means may include, for example, Figure 1-Figure 4 and Figure 7 Any disclosed device and / or functional unit for implementing the embodiments.

[0138] On the other hand, it relates to a computer program product, stored on a non-transitory memory medium, comprising computer program code, which, when executed by at least one processor, causes an apparatus to at least perform: in an idle mode of a radio resource control (RRC) protocol of a first radio access technology, reside in a first cell using at least the first radio access technology; in response to receiving signaling information from the first cell, identify the first cell as a dynamic spectrum sharing cell, wherein the spectrum sharing provides support for a second cell supporting a second radio access technology, and the signaling information includes information for establishing a connection to the second cell; send a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receive a random access preamble response from the first cell; redirect to the second cell supporting the second radio access technology based on the random access preamble response; and perform signaling for converting the apparatus to a connection mode of the radio resource control (RRC) protocol of the second radio access technology.

[0139] Another aspect relates to an apparatus, such as an access node, such as a gNB, for providing a 5G DDS cell. For example, an apparatus may include: a component for providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the apparatus, the at least one random access preamble indicating a request to be redirected to a second cell supporting at least a second radio access technology; a component for sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; a component for receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least the second radio access technology; a component for sending an indication of transitioning to an active state to the second cell; and a component for sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to camp on the second cell supporting at least the second radio access technology.

[0140] According to an embodiment, the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

[0141] According to an embodiment, the apparatus comprises: means including means for including one or more of the following in a random access preamble response (RAR) message: - information for redirecting the user equipment to the second cell; - assistance information on uplink timing information to the second cell for the user equipment; -Assistance information about downlink timing; - information about an aperiodic or periodic signal for fine tuning the frequency or time of the second cell; - information about the beam of the second cell relative to the beam of the first cell; - Grant for uplink transmission in the second cell.

[0142] According to an embodiment, the signaling information comprises information on service-based usage of random access preambles associated with the first radio access technology and the second radio access technology.

[0143] According to an embodiment, the apparatus comprises means for configuring the user equipment to perform inter-radio access technology measurements for an intra-radio access technology handover for a target dynamic spectrum sharing cell in which the second radio access technology is not active.

[0144] Such a device may also include at least one processor and at least one memory, at least one memory having computer program code stored thereon, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least perform: providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the device, and at least one random access preamble indicates a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least the second radio access technology; sending an indication to the second cell to transition to an active state; and sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to reside on the second cell supporting at least the second radio access technology.

[0145] On the other hand, it relates to a computer program product, stored on a non-transitory memory medium, comprising computer program code, which, when executed by at least one processor, causes an apparatus to at least perform: providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the apparatus, the at least one random access preamble indicating a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to a second cell supporting at least the second radio access technology; sending an indication to the second cell to transition to an active state; and sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to reside on the second cell supporting at least the second radio access technology.

[0146] Another aspect relates to an apparatus, such as an access node, such as a gNB, for providing a 6G DDS cell. For example, an apparatus may include: a component for providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble for a device in a first cell providing a dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; a component for configuring the apparatus to operate in an inactive state; a component for receiving an indication of a transition to an active state from the first cell, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and a component for performing signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0147] According to an embodiment, the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

[0148] According to an embodiment, the apparatus comprises means for sending downlink broadcast and control information to a user equipment in an active state.

[0149] According to an embodiment, the apparatus comprises: means for starting a timer when the number of user equipments in connected mode of the RRC protocol is zero; and means for configuring the apparatus to transition to an inactive state upon expiration of the timer.

[0150] According to an embodiment, the apparatus comprises means for ceasing to send downlink broadcast and control information to user equipment in an active state.

[0151] According to an embodiment, the apparatus comprises means for notifying a core network of the transition to the inactive state.

[0152] According to an embodiment, the apparatus comprises means for notifying other cells about the transition to the inactive state using the second radio access technology.

[0153] Such a device may also include at least one processor and at least one memory, at least one memory having computer program code stored thereon, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least perform: providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble of the device in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the device to operate in an inactive state; receiving an indication of transitioning to an active state from the first cell, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and performing signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0154] On the other hand, it relates to a computer program product, stored on a non-transitory storage medium, comprising computer program code, which, when executed by at least one processor, causes an apparatus to at least perform: providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble code for an apparatus in a first cell providing a dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the apparatus to operate in an inactive state; receiving an indication of a transition to an active state from the first cell, the indication being triggered by a random access preamble code received by the first cell from at least one user equipment via the first radio access technology, the random access preamble code indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; and performing signaling for transitioning the user equipment to a connection mode of a radio resource control (RRC) protocol of the second radio access technology.

[0155] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits or any combination thereof. Although various aspects of the present disclosure may be shown and described as block diagrams or using some other graphical representations, it should be understood that these blocks, devices, systems, techniques or methods described herein may be implemented as hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof in non-limiting examples.

[0156] Embodiments of the present disclosure may be practiced in various components such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert logic level designs into semiconductor circuit designs that are ready to be etched and formed on a semiconductor substrate.

[0157] Programs such as those provided by Synopsys, Inc. of Mountain View, Calif., and Cadence Design, of San Jose, Calif., automatically route conductors and position components on a semiconductor chip using established design rules and a library of pre-stored design modules. Once a design for a semiconductor circuit is complete, the resulting design in a standardized electronic format (e.g., Opus, GDSII, etc.) can be transmitted to a semiconductor manufacturing facility or "fab" for fabrication.

[0158] The above description provides a complete and informative description of exemplary embodiments of the present disclosure by way of exemplary and non-limiting examples. However, in view of the foregoing description, various modifications and adaptations may become apparent to those skilled in the relevant art when read in conjunction with the accompanying drawings and the accompanying examples. However, all of these and similar modifications of the teachings of the present disclosure will still fall within the scope of the present disclosure.

Claims

1. A device comprising: means for establishing a connection to a cell using a first radio access technology and a second radio access technology; means for camping on a first cell using at least the first radio access technology in an idle mode of a radio resource control (RRC) protocol of the first radio access technology; means for identifying the first cell as a dynamic spectrum sharing cell in response to receiving signaling information from the first cell, wherein spectrum sharing provides support for a second cell supporting the second radio access technology, and the signaling information includes information for establishing a connection to the second cell; means for sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; means for receiving a random access preamble response from the first cell; means for redirecting to the second cell supporting the second radio access technology based on the random access preamble response; as well as Means for performing signaling for transitioning the apparatus to a connected mode of the radio resource control (RRC) protocol of the second radio access technology. 2 . The apparatus according to claim 1 , wherein the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

3. The device according to claim 1 or 2, comprising: Means for performing downlink coarse time and frequency tracking for the second cell based on signals of the first cell.

4. The device according to any one of the preceding claims, comprising: means for transitioning from said connected mode to said idle mode; means for performing measurements on the second cell; as well as Means for redirecting the connection to the first cell in response to detecting that the second cell is out of coverage.

5. The device according to any one of the preceding claims, comprising: means for performing inter-radio access technology measurements between a plurality of cells supporting at least the first radio access technology and the second radio access technology; means for detecting a need for switching; as well as Means for, in response to detecting that a target cell supporting the handover of the second radio access technology is inactive, redirecting the connection to a dynamic spectrum sharing cell corresponding to the target cell and using the measurements of the first radio access technology.

6. The device according to any one of the preceding claims, comprising: Means for displaying, in response to identifying the cell as a dynamic spectrum sharing cell, a first indication on a display of the apparatus, the first indication being used to indicate that a connection to the second cell supporting at least the second radio access technology is available.

7. The device according to any one of the preceding claims, comprising: means for displaying a second indication on the display of the apparatus in response to entering the second cell in connected mode, the second indication being used to indicate that a connection to the second cell supporting at least the second radio access technology has been established.

8. The apparatus of any preceding claim, wherein the signaling information comprises information on service-based usage of the random access preamble associated with the first radio access technology and the second radio access technology.

9. The device according to claim 8, comprising: Means for selecting a preamble from either the first radio access technology or the second radio access technology based on a type of service being initiated.

10. The apparatus of any preceding claim, wherein the random access preamble response comprises timing advance information and downlink timing received from the first cell using the first radio access technology, the apparatus comprising: Means for synchronizing a downlink and an uplink of the second cell using the second radio access technology using the timing advance information and the downlink timing of the first cell using the first radio access technology.

11. The device according to any one of the preceding claims, comprising: Means for obtaining non-required system information after redirecting to the second cell using the second radio access technology.

12. A method comprising: camping on a first cell using at least the first radio access technology, by an apparatus in an idle mode of a radio resource control (RRC) protocol of a first radio access technology, the apparatus comprising means for establishing a connection to the cell using the first radio access technology and a second radio access technology; identifying the first cell as a dynamic spectrum sharing cell in response to receiving signaling information from the first cell, wherein spectrum sharing provides support for a second cell supporting the second radio access technology, and the signaling information includes information for establishing a connection to the second cell; sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receiving a random access preamble response from the first cell; redirecting, based on the random access preamble response, to the second cell supporting the second radio access technology; as well as Signaling for transitioning the apparatus to a connected mode of the radio resource control (RRC) protocol of the second radio access technology is performed.

13. An apparatus comprising at least one processor and at least one memory having computer program code stored thereon, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least perform: camping on a first cell using at least the first radio access technology in an idle mode of a radio resource control (RRC) protocol of a first radio access technology; identifying the first cell as a dynamic spectrum sharing cell in response to receiving signaling information from the first cell, wherein spectrum sharing provides support for a second cell supporting the second radio access technology, and the signaling information includes information for establishing a connection to the second cell; sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receiving a random access preamble response from the first cell; redirecting, based on the random access preamble response, to the second cell supporting the second radio access technology; as well as Signaling for transitioning the apparatus to a connected mode of the radio resource control (RRC) protocol of the second radio access technology is performed.

14. A computer program product, stored on a non-transitory memory medium, comprising computer program code which, when executed by at least one processor, causes an apparatus comprising means for establishing a connection to a cell using a first radio access technology and a second radio access technology to at least perform: camping on a first cell using at least the first radio access technology in an idle mode of a radio resource control (RRC) protocol of the first radio access technology; identifying the first cell as a dynamic spectrum sharing cell in response to receiving signaling information from the first cell, wherein spectrum sharing provides support for a second cell supporting the second radio access technology, and the signaling information includes information for establishing a connection to the second cell; sending a random access preamble to the first cell, the random access preamble indicating a request to be redirected to the second cell supporting the second radio access technology; receiving a random access preamble response from the first cell; redirecting, based on the random access preamble response, to the second cell supporting the second radio access technology; as well as Signaling for transitioning the apparatus to a connected mode of the radio resource control (RRC) protocol of the second radio access technology is performed.

15. An apparatus comprising: means for providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the apparatus, the at least one random access preamble indicating a request to be redirected to a second cell supporting at least a second radio access technology; means for sending signalling information to at least one user equipment via the first radio access technology, wherein the signalling information comprises information for establishing a connection to the second cell; means for receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; means for sending an indication to the second cell to transition to an active state; as well as Means for sending a random access preamble response to the user equipment via the first radio access technology, wherein the random access preamble response comprises signaling for redirecting the user equipment to camp on a second cell supporting at least the second radio access technology.

16. The apparatus of claim 15, wherein the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

17. The device according to claim 15 or 16, comprising: means, comprising means for including one or more of the following in the random access preamble response (RAR) message: - information for redirecting the user equipment to the second cell; - assistance information about uplink timing information to the second cell for the user equipment; -Assistance information about downlink timing; - information about an aperiodic or periodic signal for fine tuning the frequency or time of the second cell; - information about the beam of the second cell relative to the beam of the first cell; - a grant for uplink transmission in said second cell.

18. The apparatus according to any one of claims 15 to 17, the signaling information comprising information on service-based usage of the random access preamble associated with the first radio access technology and the second radio access technology.

19. The device according to any one of claims 15 to 18, comprising: Means for configuring the user equipment to perform inter-radio access technology measurements for an intra-radio access technology handover of a target dynamic spectrum sharing cell wherein the second radio access technology is inactive.

20. A method comprising: providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the means for providing the first cell, the at least one random access preamble indicating a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; sending an instruction to switch to an active state to the second cell; as well as A random access preamble response is sent to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to camp on the second cell supporting at least the second radio access technology.

21. An apparatus comprising at least one processor and at least one memory having computer program code stored thereon, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least perform: providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the apparatus, the at least one random access preamble indicating a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; sending an instruction to switch to an active state to the second cell; as well as A random access preamble response is sent to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to camp on a second cell supporting at least the second radio access technology.

22. A computer program product, stored on a non-transitory memory medium, comprising computer program code which, when executed by at least one processor, causes an apparatus to at least perform: providing a first cell, the first cell being a dynamic spectrum sharing cell supporting at least a first radio access technology, wherein at least one random access preamble is stored in the apparatus, the at least one random access preamble indicating a request to be redirected to a second cell supporting at least a second radio access technology; sending signaling information to at least one user equipment via the first radio access technology, wherein the signaling information includes information for establishing a connection to the second cell; receiving a random access preamble from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; sending an instruction to switch to an active state to the second cell; as well as A random access preamble response is sent to the user equipment via the first radio access technology, wherein the random access preamble response includes signaling for redirecting the user equipment to camp on a second cell supporting at least the second radio access technology.

23. An apparatus comprising: means for providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble for the apparatus in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; means for configuring the device to operate in an inactive state; means for receiving, from the first cell, an indication to transition to an active state, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; as well as Means for performing signaling for transitioning the user equipment to a connected mode of a Radio Resource Control (RRC) protocol of the second radio access technology.

24. The apparatus of claim 23, wherein the random access preamble is a random access preamble dedicated to the second cell supporting the second radio access technology.

25. The device according to claim 23 or 24, comprising: Means for sending downlink broadcast and control information to said user equipment in said active state.

26. The device according to any one of claims 23 to 25, comprising: means for starting a timer when the number of said user equipments in said connected mode of said RRC protocol is zero; as well as Means for configuring the apparatus to transition to an inactive state upon expiration of the timer.

27. The apparatus according to claim 26, comprising: Means for ceasing to send downlink broadcast and control information to said user equipment in said active state.

28. The apparatus according to claim 26 or 27, comprising: Means for notifying a core network of said transition to said inactive state.

29. The device according to any one of claims 26 to 28, comprising: Means for notifying other cells about the transition to the inactive state using the second radio access technology.

30. A method comprising: providing, by an apparatus, a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble for the apparatus in a first cell providing a dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the device to operate in an inactive state; receiving, from the first cell, an indication to transition to an active state, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; as well as Signaling for transitioning the user equipment to a connected mode of the radio resource control (RRC) protocol of the second radio access technology is performed.

31. An apparatus comprising at least one processor and at least one memory having computer program code stored thereon, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least perform: providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble for the apparatus in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the device to operate in an inactive state; receiving, from the first cell, an indication to transition to an active state, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; as well as Signaling for transitioning the user equipment to a connected mode of the radio resource control (RRC) protocol of the second radio access technology is performed.

32. A computer program product, stored on a non-transitory storage medium, comprising computer program code, which when executed by at least one processor causes an apparatus to at least perform: providing a second cell, the second cell being a dynamic spectrum sharing cell supporting at least a second radio access technology, wherein at least one random access preamble for the apparatus in the first cell providing the dynamic spectrum sharing cell supporting at least a first radio access technology indicates a request for a user equipment to be redirected; configuring the device to operate in an inactive state; receiving, from the first cell, an indication to transition to an active state, the indication being triggered by a random access preamble received by the first cell from at least one user equipment via the first radio access technology, the random access preamble indicating a request for the user equipment to be redirected to the second cell supporting at least the second radio access technology; as well as Signaling for transitioning the user equipment to a connected mode of the radio resource control (RRC) protocol of the second radio access technology is performed.

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