Cell selection for initial access

Abstract

The present document discloses a scheme for selecting a cell for initial access. According to one aspect, a method includes camping in a first cell and detecting a second cell in a sleep state; obtaining an initial access configuration, wherein the initial access configuration maps the service type and the sleep state with a cell for initial access; obtaining data for an uplink transmission; if the traffic type of the data is the first traffic type and the sleep state of the second cell is the first sleep state, transmitting a wake-up signal to the second cell, transmitting an initial access message to the second cell, and transmitting the data via the second cell; if the traffic type of the data is a second traffic type different from the first traffic type, and if the sleep state of the second cell is a second sleep state, transmitting a wake-up signal to the second cell, transmitting an initial access message to the second cell, and transmitting the data via the second cell; and transmitting an initial access message to the first cell and transmitting data via the first cell under another condition defined in the initial access configuration and based on the traffic type and the sleep state of the second cell.

Description

Technical Field

[0001] Various embodiments described herein relate to the field of wireless communications, and more particularly, to selecting a cell for initial access of a terminal device. Background Art

[0002] In the development of wireless communication systems, the power consumption of terminal devices of wireless communication systems has always been an area of ​​concern. The power consumption of network infrastructure, especially radio access networks, is also an important factor. There are some methods for reducing power consumption, such as the relaxed transmission of signaling information by access nodes, which allows the transmitter circuit of the access node to be temporarily turned off. Some wireless systems support access nodes to enter a sleep state, in which it deactivates at least some functions in order to save power. Sleeping access nodes can be awakened to communicate with terminal devices. However, in the case where uplink data needs to be sent, decision logic is needed to determine whether to wake up the sleeping cell. Summary of the invention

[0003] Some aspects of the invention are defined by the independent claims.

[0004] Some embodiments of the invention are defined in the dependent claims.

[0005] Embodiments and features described in this specification that do not belong to the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the present invention. Some aspects of the present disclosure are defined by the independent claims.

[0006] According to one aspect, an apparatus for a terminal device is provided, comprising: a component for performing the following operations: residing in a first cell and detecting a second cell in a sleep state; obtaining an initial access configuration, the initial access configuration mapping a service type with a sleep state and a cell for initial access; obtaining data for uplink transmission; if the service type of the data is a first service type and the sleep state of the second cell is a first sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending data via the second cell; if the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is a second sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending data via the second cell; and under another condition defined in the initial access configuration and based on the service type and sleep state of the second cell, sending an initial access message to the first cell, and sending data via the first cell.

[0007] In one embodiment, the component is configured to: determine the strength of a reference signal received from the second cell when the second cell is in a sleep state; if the strength of the reference signal is higher than a threshold, send the wake-up signal to the second cell; and if the strength of the reference signal is lower than the threshold, send the initial access message to the first cell and send data via the first cell.

[0008] In an embodiment, the component is configured to: if the service type is a third service type, send an initial access message to the first cell and send data via the first cell, and wherein the first service type is associated with a first delay requirement, the second service type is associated with a second delay requirement, and the third service type is associated with a third delay requirement, and the third delay requirement defines a delay requirement that is more stringent than the first service type and the second service type.

[0009] In an embodiment, the component is configured to: if the sleep state is a third sleep state, send an initial access message to the first cell and send data via the first cell, and wherein the first sleep state is associated with a first wake-up delay, the first wake-up delay defining a delay taken for the second cell to wake up from the sleep state, wherein the second sleep state is associated with a second wake-up delay that is shorter than the first wake-up delay, and wherein the third sleep state is associated with a third wake-up delay that is longer than the first wake-up delay and the second wake-up delay.

[0010] In an embodiment, the component is configured to: if the traffic type is the second traffic type, and if the sleep state is the first sleep state, send an initial access message and send data via the first cell.

[0011] In an embodiment, the initial access configuration provides at least the following information:

[0012] In an embodiment, the means are configured to determine a traffic load in the first cell and, if the traffic load is above a threshold, send a wake-up signal and an initial access message to the second cell and send data via the second cell.

[0013] In an embodiment, the component is configured to: determine the strength of a reference signal received from the first cell when the second cell is in a sleep state; if the strength of the reference signal is below a threshold, send a wake-up signal to the second cell; and if the strength of the reference signal is above the threshold, send an initial access message to the first cell and send data via the first cell.

[0014] In an embodiment, at least some communication functions of the second cell are unavailable to the device during the sleep state.

[0015] In an embodiment, the initial access message sent to the second cell comprises a wake-up signal.

[0016] In an embodiment, the means are configured to receive an initial access configuration from the first cell.

[0017] In an embodiment, the component is configured to, when selecting the second cell for initial access, send a wake-up signal to the second cell before sending an initial access message to the second cell.

[0018] In an embodiment, the means are configured to receive an initial access configuration from the second cell before the second cell enters a dormant state.

[0019] According to an aspect, an apparatus is provided, comprising components for performing the following operations: obtaining an initial access configuration, the initial access configuration mapping a service type with a sleep state and with a cell for initial access; sending the initial access configuration; and receiving an initial access message and uplink data from a terminal device.

[0020] In an embodiment, the component is configured to trigger entry into the sleep state and, in response to the trigger, transmit the initial access configuration before entering the sleep state.

[0021] In an embodiment, a component comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause execution of the apparatus.

[0022] According to one aspect, a method is provided, comprising: a terminal device resides in a first cell, and detects a second cell in a sleep state; the terminal device obtains an initial access configuration, the initial access configuration mapping a service type with a sleep state and a cell for initial access; the terminal device obtains data for uplink transmission; if the service type of the data is a first service type, and the sleep state of the second cell is a first sleep state, the terminal device sends a wake-up signal to the second cell, sends an initial access message to the second cell, and sends data via the second cell; if the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is a second sleep state, the terminal device sends a wake-up signal to the second cell, sends an initial access message to the second cell, and sends data via the second cell; and under other conditions defined in the initial access configuration, and based on the service type and the sleep state of the second cell, the terminal device sends an initial access message to the first cell, and sends data via the first cell.

[0023] In an embodiment, the method further comprises, by the terminal device: When the second cell is in a sleep state, determining a strength of a reference signal received from the second cell, If the strength of the reference signal is higher than the threshold, sending a wake-up signal to the second cell, and If the strength of the reference signal is lower than the threshold, an initial access message is sent to the first cell, and data is sent via the first cell.

[0024] In an embodiment, if the service type is a third service type, the terminal device sends an initial access message to the first cell and sends data via the first cell, and the first service type is associated with a first delay requirement, the second service type is associated with a second delay requirement, and the third service type is associated with a third delay requirement, and the third delay requirement defines a delay requirement that is more stringent than the first service type and the second service type.

[0025] In an embodiment, if the sleep state is a third sleep state, the terminal device sends an initial access message to the first cell and sends data via the first cell, and wherein the first sleep state is associated with a first wake-up delay, the first wake-up delay defines the delay taken for the second cell to wake up from the sleep state, wherein the second sleep state is associated with a second wake-up delay that is shorter than the first wake-up delay, and wherein the third sleep state is associated with a third wake-up delay that is longer than the first wake-up delay and the second wake-up delay.

[0026] In an embodiment, if the service type is the second service type, and if the sleep state is the first sleep state, the terminal device sends an initial access message and sends data via the first cell.

[0027] In an embodiment, the initial access configuration provides at least the following information:

[0028] In an embodiment, the terminal device determines the traffic load of the first cell, and if the traffic load is higher than a threshold, sends a wake-up signal and an initial access message to the second cell, and sends data via the second cell.

[0029] In an embodiment, the terminal device: When the second cell is in a sleep state, determining a strength of a reference signal received from the first cell, If the strength of the reference signal is lower than the threshold, sending a wake-up signal to the second cell, and If the strength of the reference signal is higher than the threshold, an initial access message is sent to the first cell, and data is sent via the first cell.

[0030] In an embodiment, at least some communication functions of the second cell are unavailable to the terminal device during the sleep state.

[0031] In an embodiment, the initial access message sent to the second cell comprises a wake-up signal.

[0032] In an embodiment, the terminal device receives an initial access configuration from the first cell.

[0033] In an embodiment, when the terminal device selects the second cell for initial access, the terminal device sends a wake-up signal to the second cell before sending an initial access message to the second cell.

[0034] In an embodiment, before the second cell enters the sleep state, the terminal device receives an initial access configuration from the second cell.

[0035] According to one aspect, a method is provided, comprising: obtaining, by an access node, an initial access configuration, the initial access configuration mapping a service type with a sleep state and a cell for initial access; sending, by the access node, the initial access configuration; and receiving, by the access node, an initial access message and uplink data from a terminal device.

[0036] In an embodiment, the access node triggers entering the sleep state and, in response to the trigger, sends an initial access configuration before entering the sleep state.

[0037] According to one aspect, a computer program product is provided, which is embodied on a computer-readable medium and includes a computer program code that can be read by a computer, wherein the computer program code configures the computer to implement a computer process, the computer process including: obtaining an initial access configuration, the initial access configuration mapping a service type with a sleep state and a cell for initial access; sending the initial access configuration; and receiving an initial access message and uplink data from a terminal device.

[0038] According to one aspect, a computer program product is provided, which is embodied on a computer-readable medium and includes a computer program code that can be read by a computer, wherein the computer program code configures the computer to implement a computer process, the computer process including: residing in a first cell and detecting a second cell in a sleep state; obtaining an initial access configuration, the initial access configuration mapping a service type with a sleep state and a cell for initial access; obtaining data for uplink transmission; if the service type of the data is a first service type and the sleep state of the second cell is a first sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending data via the second cell; if the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is a second sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending data via the second cell; and under another condition defined in the initial access configuration and based on the service type and the sleep state of the second cell, sending an initial access message to the first cell and sending data via the first cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Embodiments are described below by way of example only with reference to the accompanying drawings, in which

[0040] Figure 1 and 2 Wireless communication scenarios in which some embodiments of the present invention can be applied are shown;

[0041] Figure 3 shows a flow chart of a cell selection process according to an embodiment;

[0042] Figures 4 to 6 Disclosed is a method for using various criteria in a cell selection process Figure 3 Various embodiments of the process of; and

[0043] Figure 7 shows a flow chart of cell selection logic according to an embodiment;

[0044] Figure 8 and 9 shows a signalling diagram according to some embodiments; and

[0045] Fig.10 and Fig.11 A block diagram of an apparatus according to some embodiments is shown. DETAILED DESCRIPTION

[0046] The following embodiments are examples. Although the specification may refer to "one", "an" or "some" embodiments in several places, this does not necessarily mean that each such reference is to the same embodiment, or that the feature applies to only a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments. In addition, the words "comprises" and "comprising" should be understood as not limiting the described embodiments to consist only of those features that have been mentioned, and such embodiments may also include features / structures that are not specifically mentioned.

[0047] In the following, a radio access architecture based on Long Term Evolution Advanced (LTE-Advanced, LTE-A) or New Radio (NR, 5G) will be used as different exemplary embodiments as examples of access architectures to which the embodiments may be applied, without however limiting the embodiments to such architectures. Those skilled in the art will appreciate that the embodiments may also be applied to other kinds of communication networks with suitable devices by appropriately adjusting parameters and procedures. 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, same as E-UTRA), Wireless Local Area Network (WLAN or WiFi), Worldwide Interoperability for Microwave Access (WiMAX), Personal Communications Service (PCS), Wideband Code Division Multiple Access (WCDMA), ZigBee Systems using Ultra-Wideband (UWB) technology, sensor networks, mobile ad hoc networks (MANETs), and Internet Protocol Multimedia Subsystems (IMS), or any combination thereof.

[0048] Figure 1 An example of a simplified system architecture is depicted, showing only some elements and functional entities, all of which are logical units, the implementation of which may differ from what is shown. Figure 1 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 1 Other functions and structures than those shown.

[0049] 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 provided with the necessary properties.

[0050] Figure 1 The example of FIG. 1 shows a portion of an exemplary radio access network.

[0051] Figure 1Terminal devices or user equipment 100 and 102 are shown, which are configured to be in wireless connection with an access node (such as (e / g) NodeB) 104 providing the cell on one or more communication channels in the cell. (e / g) NodeB refers to eNodeB or gNodeB defined in the 3GPP specification. The physical link from the user equipment to the (e / g) NodeB is called an uplink or reverse link, and the physical link from the (e / g) NodeB to the user equipment is called a downlink or forward link. It should be understood that the (e / g) NodeB or its functions can be implemented by using any node, host, server or access point entity suitable for such use.

[0052] The communication system usually includes more than one (e / g)NodeB, in which case the (e / g)NodeB can also be configured to communicate with each other through links designed for the purpose, wired or wireless. These links can be used not only for signaling purposes, but also for routing data from one (e / g)NodeB to another NodeB. (e / g)NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. NodeB can also be referred to as a base station, access point, access node or any other type of interface device, including a relay station capable of operating in a wireless environment. (e / g)NodeB includes or is coupled to a transceiver. A connection is provided from the transceiver of the (e / g)NodeB to an antenna unit, which establishes a two-way radio link to a user equipment. The antenna unit may include multiple antennas or antenna elements. (e / g)NodeB is also connected to a core network 110 (CN or next generation core network NGC). Depending on the system, the counterpart on the CN side may be a Serving Gateway (S-GW, routing and forwarding user data packets), a Packet Data Network Gateway (P-GW), used to provide connectivity for User Equipment (UE) to external packet data networks or a Mobility Management Entity (MME), etc.

[0053] A user equipment (also referred to as UE, user device, user terminal, terminal device, etc.) shows a type of device to which resources on the air interface are assigned and allocated, and therefore any features described herein using user equipment can be implemented with corresponding devices (such as relay nodes). An example of such a relay node is a layer 3 relay (self-backhaul relay) toward a base station. The 5G specification defines two relay modes: out-of-band relays of the same or different carriers can be defined for access links and backhaul links. In-band relays where the same carrier frequency or radio resources are used for both access links and backhaul links. In-band relays can be considered as baseline relay scenarios. Relay nodes are called integrated access and backhaul (IAB) nodes. It also has built-in support for multiple relay hops. IAB operation assumes a so-called split architecture with a CU and multiple DUs. The IAB node contains two separate functions: the DU (distributed unit) portion of the IAB node supports the gNB (access node) function in the relay cell, i.e., it acts as an access link; and the mobile terminal (MT) portion of the IAB node that supports the backhaul connection. The donor node (DU part) communicates with the MT part of the IAB node and it has a wired connection to the CU which again has a connection to the core network. In a multi-hop scenario, the MT part (child IAB node) communicates with the DU part of the parent IAB node.

[0054] User equipment generally refers to a portable computing device including a wireless mobile communication device operating with or without a subscriber identity module (SIM), including but not limited to the following types of devices: mobile station (mobile phone), smart phone, personal digital assistant (PDA), mobile phone, device using a wireless modem (alarm or measurement device, etc.), laptop computer and / or touch screen computer, tablet computer, game console, notebook and multimedia device. It should be understood that the user equipment can also be an almost dedicated uplink-only device, an example of which is a camera or video camera that loads images or video clips to a network. The user equipment can also be a device with the ability to operate in an Internet of Things (IoT) network, which is a scenario in which objects are provided with the ability to transmit data over a network without human-to-human or human-to-computer interaction. The user equipment can also utilize the cloud. In some applications, the user equipment may include a small portable device (such as a watch, headset or glasses) with a radio component, and performs calculations in the cloud. The user equipment (or in some embodiments, a layer 3 relay node) is configured to perform one or more of the user equipment functions. A user device may also be called a subscriber unit, a mobile station, a remote terminal, an access terminal, a user terminal, or user equipment (UE), just to name a few names or devices.

[0055] The various techniques described herein may also be applied to cyber-physical systems (CPS) (systems of cooperating computing elements that control physical entities). CPS may support 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, in which 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.

[0056] Additionally, although the apparatus has been depicted as a single entity, different units, processors and / or memory units may be implemented. Figure 1 not shown).

[0057] 5G supports the use of multiple-input multiple-output (MIMO) antennas, many more base stations or nodes than LTE (the so-called small cell concept), including macro sites operating in coordinated operation with smaller stations, and employing various radio technologies depending on service requirements, use cases and / or spectrum. 5G mobile communications support a wide range of use cases and related applications, including video streaming, augmented reality, different ways of sharing data, 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 sub-6GHz, centimeter wave (cmWave) and millimeter wave (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, in which 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 sub-6GHz-cmWave, sub-6GHz-cmWave-mmWave). One of the concepts considered for use in 5G networks is network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) can be created within the same infrastructure to run services with different requirements for latency, reliability, throughput and mobility.

[0058] The current architecture in LTE networks is completely distributed in the radio and is usually 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 supports analysis and knowledge generation at the data source. This method requires the use of resources that may be discontinuously connected to the network, 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 to obtain 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 / mesh computing, dew computing, mobile edge computing, micro cloud (cloudlet), distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (large-scale connection and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analysis, time-critical control, healthcare applications).

[0059] The communication system can also communicate with or utilize services provided by other networks 112, such as the public switched telephone network or the Internet. The communication network can also support the use of cloud services, for example, at least a portion of the core network operations can be implemented as a cloud service (this is in the Figure 1 114). 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.

[0060] Edge cloud can be introduced into the radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using edge cloud can mean implementing access node operations at least partially in a server, host or node operatively 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 implemented on the RAN side (in distributed units DU 105), while non-real-time functions are implemented in a centralized manner (in centralized units CU 108).

[0061] It should also be understood that the distribution of functions between core network operations and base station operations may be different from that of 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 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.

[0062] 5G may also utilize satellite communications to enhance or supplement the coverage of 5G services, for example, by providing backhaul. Possible use cases are to provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or passengers in vehicles, or to ensure service availability for critical communications and future railway, maritime and / or aviation communications. Satellite communications may utilize geostationary earth orbit (GEO) satellite systems, but may also utilize low earth orbit (LEO) satellite systems, especially large constellations (systems in which hundreds of (nano) satellites are deployed). Each satellite 109 in a large constellation may cover several satellite-supporting network entities that create cells on the ground. The cells on the ground may be created by relay nodes on the ground or by gNBs located on the ground or in satellites.

[0063] It is obvious to a person skilled in the art 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)NodeBs, a 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)NodeBs may be a home (e / g)NodeB. In addition, in a 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)NodeB can provide any type of these cells. A cellular radio system can be implemented as a multi-layer network including several types of cells. Typically, in a multi-layer network, one access node provides one or more cells of one type, so multiple (e / g)NodeBs are needed to provide this network structure.

[0064] Figure 2 A wireless communication scenario is shown in which the embodiments described below may be applied.The terminal device 100 may reside in a coverage area of ​​a cell operated by a first access node 104A and a second access node 104B. Figure 2Such a situation is shown: the second access node 104B has disabled at least some of its functions and is in a dormant state, while the first access node 104A is in an active mode and can provide all supported communication services to the terminal device. Accordingly, the terminal device can select the cell of the first access node 104A for camping in an idle state or an inactive state (camping cell). The cell managed by the access node 104B can be referred to as a sleeping cell, and the access node 104B is in a dormant state. An example of the difference between the dormant state and the active state can involve transmission. The first access node 104A can send full system information, can page the terminal device 100, and send reference signals in a short period. The second access node 104B in a dormant state can deactivate the system information transmission and paging function, and it may send reference signals with a long periodicity. The reference signal transmission may also include the information required to wake up the access node 104B, for example, the cell identifier of the dormant cell.

[0065] A camped cell may refer to a cell where a terminal device is registered for paging in an idle or inactive state. Camping enables a terminal device to receive system information from a radio access network. When registering and if the terminal device wishes to establish a radio resource control (RRC) connection or resume a suspended RRC connection, it can do so by initially accessing the network on the control channel of the cell in which it resides. If the network needs to send a message or deliver data to a registered terminal device, the radio access network knows the set of tracking areas in which the terminal device resides. A paging message for the terminal device may then be sent on the control channels of all cells in the corresponding tracking area. The terminal device will then receive the paging message and can respond. In addition, camping enables the reception of certain broadcast information from the radio access network.

[0066] The sleeping cell and the camping cell may be co-located, for example provided by the same access node.As known in the art, an access node may provide multiple cells with different coverage areas, overlapping or non-overlapping.

[0067] As described in the background art, Figure 2 When a need for uplink data transmission is detected in the case of a wireless access, the terminal device may perform a selection process to decide a cell for initial access and uplink data transmission. Figure 3 An embodiment of a process for selecting a cell for initial access is shown. The process may be implemented by an apparatus of the terminal device 100. Figure 3, the process includes: camping in a first cell (block 300) and detecting a second cell in a sleep state; obtaining (block 302) an initial access configuration, the initial access configuration mapping a traffic type with a sleep state and a cell for initial access; obtaining (block 304) data for uplink transmission, and selecting (block 306) a cell for initial access, as follows:

[0068] If the service type of the data is the first service type and the sleep state of the second cell is the first sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending data via the second cell (block 310);

[0069] If the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is the second sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending data via the second cell (block 310); and

[0070] Under another condition defined in the initial access configuration and based on the traffic type and the sleep state of the second cell, an initial access message is sent to the first cell, and data is sent via the first cell (block 308).

[0071] The above selection logic supports efficient utilization of access nodes for uplink transmission. This is achieved through the initial access configuration, which informs the terminal device under which conditions the terminal device can wake up the sleeping cell in terms of service type and the sleeping state of the sleeping cell, and under which conditions the initial access is performed via the first cell that is camped on. This can reduce unnecessary wake-up of sleeping cells for services that can be accommodated by the camped cell and reduce power consumption at the network level. It can also reduce the ping-pong effect caused by switching on and off sleeping cells.

[0072] The sleeping cell can be awakened by the terminal device via a wake-up process that follows the most advanced technology. For example, the 5G and IEEE802.11 specifications support the wake-up radio (WUR) process, and the actual wake-up process can be designed according to similar principles. The wake-up process may include the terminal device sending a wake-up signal to the sleeping cell, which wake-up signal includes the cell identifier of the sleeping cell. After the sleeping cell has been awakened and is sending system information, the terminal device can send an initial access message, such as a random access request message, to the corresponding access node. Thereafter, conventional connection establishment (e.g., radio resource control, RRC, connection establishment) and uplink data transmission can follow.

[0073] Blocks 300 and 302 may be performed in any order. For example, as described below, the initial access configuration may be obtained in various situations.

[0074] The data may comprise payload data (application layer data) and / or it may comprise signalling data.

[0075] Regarding sleep states, an access node may assume one of a plurality of supported sleep states. Each sleep state may be associated with deactivating a particular number of functions and hardware resources in the access node. For example, a sleeping cell may be in one of the following sleep states:

[0076] Micro-sleep, symbol-level sleep: Turn off the power amplifier for symbols that carry neither data nor signaling information, and send reference signals at a normal or slightly larger period;

[0077] Mini-sleep, radio frame-level sleep (10ms): off...; send reference signals with a long period;

[0078] Light sleep, second-level sleep (e.g., 1 second sleep): Partially shut down the baseband circuit system and send reference signals with a long periodicity

[0079] Deep sleep, sleep for tens of seconds (eg, 10 seconds to 30 seconds): the baseband circuitry and the radio transmitter chain are turned off.

[0080] Standby / off, wake-up time 1-2 minutes; the cell does not send synchronization signal blocks (SSBs) and / or system information blocks (SIBs); the cell is turned off or deactivated.

[0081] With respect to the different sleep states listed above, the following principles may be observed. When moving from a lighter sleep state to a deeper sleep state, additional hardware components may be turned off until a complete cell shutdown (i.e., cell deactivation) is achieved. Additionally or alternatively, the time interval between consecutive periodic broadcasts may be increased. It should be noted that the hardware components described in each sleep state are merely examples of how the corresponding sleep state may be defined. Furthermore, different systems may implement different numbers of different sleep states, e.g., one system may employ all of the sleep states listed above, while another system may employ a subset of the listed sleep states (omitting one or more of the listed sleep states, such as a mini sleep state).

[0082] As above combined Figure 2 As described, the sleeping cell can still send a reference signal so that the terminal device can detect the sleeping cell and measure the signal strength of the reference signal. In an embodiment, the terminal device determines the strength of the reference signal received from the second cell when the second cell is in a sleeping state, and sends a wake-up signal to the second cell if the strength of the reference signal is higher than a threshold. Figure 4 A flow chart showing such a process is shown in FIG. Figure 4, the terminal device may measure the signal strength of (multiple) reference signals received from the sleeping cell in block 400. The signal strength may be provided in the form of reference signal received power (RSRP), signal to interference plus noise ratio (SINR), received signal strength indicator, or another equivalent metric known in the art. In block 402, the signal strength is compared to a threshold. If the signal strength is greater than the threshold, the terminal device may enable initial access via the second cell. For example, the terminal device may resume Figure 3 The process proceeds to block 306. If the signal strength is below the threshold, the terminal device may deactivate initial access via the second cell, for example, proceeding directly from block 304 to block 308.

[0083] A further criterion for selecting a cell for initial access may be the traffic load in the camping cell. In an embodiment, the terminal device determines the traffic load in the first (camping) cell and, if the traffic load is above a threshold, sends a wake-up signal and an initial access message to the second (sleeping) cell and also sends data via the second cell. Figure 5 Such a process is shown for a terminal device. Figure 5 , in box 500, the terminal device determines the traffic load of the resident cell. The resident cell may report the traffic load via broadcast system information, in which case the terminal device reads the traffic load directly. The traffic load may be reported via various metrics, for example, based on the latency provided by the access node or the amount of idle (unallocated) resources relative to the allocated resources. Other metrics are conceivable. In another solution, the terminal device may measure the amount of traffic between the access node 104A of the resident cell and other terminal devices served by the access node 104A. In box 502, the terminal device compares the traffic load with a threshold. In the event that the comparison indicates that the traffic load in the resident cell is above the threshold, the terminal device may enable initial access via a second (sleeping) cell. For example, the terminal device may resume Figure 3 The process proceeds to block 306. If the comparison indicates that the traffic load is below the threshold, the terminal device may deactivate initial access via the second cell, for example proceeding directly from block 304 to block 308.

[0084] In an embodiment, the terminal device determines the strength of a reference signal received from a first (resident) cell when the second cell is in a sleep state, sends a wake-up signal to the second cell if the strength of the reference signal is below a threshold, and sends an initial access message to the first cell and sends data via the first cell if the strength of the reference signal is above the threshold. Figure 6 An embodiment of such a process for a terminal device is shown. Figure 6, the terminal device measures and determines the signal strength of the reference signal(s) received from the camped cell. The signal strength may be provided in the form of any of the above metrics. Then, in block 602, the terminal device compares the determined signal strength with a threshold. If the signal strength is below the threshold, the terminal device may enable initial access via the second cell. For example, the terminal device may resume Figure 3 The process proceeds to block 306. If the signal strength is above the threshold, the terminal device may deactivate initial access via the second cell, for example, proceeding directly from block 304 to block 308.

[0085] The threshold used in block 602 may be combined with the above Figure 4 The thresholds described are the same, or they may have different thresholds. For example, the threshold used in block 602 may be lower than the threshold used in block 402. When only signal strength is considered as a criterion for selecting a cell for initial access, it means that the terminal device may prefer a camping cell rather than a sleeping cell, thereby allowing the sleeping cell to sleep with a greater probability.

[0086] In an embodiment, the initial access message sent to the sleeping cell includes a wake-up signal. In such an embodiment, the random access request message may serve as a wake-up signal for the sleeping cell. In another embodiment, the terminal device first sends a wake-up signal to wake up the sleeping second cell, and upon receiving system information from the second cell, the terminal device sends an initial access message, such as a random access request message. The initial access message sent to the resident cell may include a random access request message.

[0087] In an embodiment, if the service type is a third service type, the terminal device sends an initial access message to the first cell and sends data via the first cell, wherein the first service type is associated with a first delay requirement, the second service type is associated with a second delay requirement, and the third service type is associated with a third delay requirement, and the third delay requirement defines a delay requirement that is more stringent than the first service type and the second service type. In other words, a high priority service with a strict delay requirement (requiring low delay) can be associated with initial access via a resident cell in the initial access configuration.

[0088] In an embodiment, if the service type is the second service type, and if the sleep state is the first sleep state, the terminal device sends the initial access message and data via the first cell. For example, if the service type is the second service type that establishes a more stringent latency requirement, and the first sleep state is the above-mentioned deep sleep state that causes a greater latency than the second sleep state, the terminal device may select the first (residence) cell for initial access and data transmission.

[0089] Let us then describe some embodiments of the initial access configuration using at least the service type and the sleep state of the sleeping cell. As described above, the initial access configuration can define the cell to which the terminal device should send the initial access message for various combinations of at least the service type and the sleep state. The service type can be defined according to the service type or service identifier (such as a logical channel group identifier, a logical channel identifier, a data radio bearer identifier, etc.), an access class or access category or a quality of service (QoS) class that defines different access classes with different latency requirements, or another classification that can define different priority levels for different service types. For example, the sleep state can follow the above-described embodiments. However, it should be noted that different systems may adopt different configurations of different sleep states, and the number of sleep states may be greater or less than that described above.

[0090] In an embodiment, the initial access configuration provides at least the following information: Table 1

[0091] The above table illustrates the following logic. In this case, the first service type is associated with a loose delay requirement such as file transfer, and belongs to a first service type set that can define various levels of such loose delay requirements. In this case, the second service type is associated with a more stringent delay requirement such as music streaming, and belongs to a second service type set that can define various levels of such more stringent delay requirements. In this case, the third service type is associated with a more stringent delay requirement (e.g., emergency data or video call), and belongs to a third service type set that can define various levels of such very strict delay requirements. Since the delay requirement of the first service type set is loose, the terminal device is allowed to wake up the sleeping cell even when the sleeping cell is in a deeper sleep state (e.g., shallow sleep, deep sleep, or even standby state). In the case of more stringent delay requirements, the terminal device can be allowed to wake up the sleeping cell only when the sleeping state is one of the sleeping states with a relatively short wake-up delay (e.g., mini sleep or micro sleep). If the sleeping state is deep sleep or standby, the terminal device can be configured to send an initial access message to the first cell where it resides. In the case of the third service type set, the terminal device may be configured to access only cells that are not in a sleep state, so the terminal device will send an initial access message to the first cell. A more detailed initial access configuration table is provided below. Table 2

[0092] Referring to Table 2 above, the initial access configuration may define a sleep state threshold for each service type, which is used as a boundary for selecting a resident cell or a detected sleeping cell for initial access. As described in the table, the sleep state threshold is different for different service types. The sleep state threshold may be defined directly based on the sleep state or via an intermediate metric such as wake-up delay. As shown in the table, the highest priority service may always veto the sleeping cell selection, thereby avoiding cell reselection and accessing via the resident cell, thereby providing minimum latency.

[0093] As described above, the signal strength of the camping cell and / or the detected sleeping cell can serve as a further input for cell selection. As described above, the signal strength can be used as a criterion as to whether the sleeping cell can be considered at all. In another embodiment, the signal strength is incorporated into the selection logic, for example, as provided below for a single service type. The same principles can be applied to other service types. Table 3

[0094] In Table 3, CS refers to "camping cell" and SS refers to "sleeping cell". As shown in the above table, the initial access configuration can provide rules for the terminal device to select a cell for initial access for each service type, each sleeping state of the sleeping cell, and each signal strength of the camping cell and / or the sleeping cell.

[0095] In a similar manner, the traffic load of the resident cell can be used for cell selection. The following table shows an embodiment for mapping the traffic load as an additional parameter to cell selection. Again, the traffic load is shown for one type of traffic, but the same principle can be applied to other types of traffic in a similar manner. Table 4

[0096] As shown in the table, the same or different traffic load thresholds can be applied to different sleep states. In the same way, the same or different traffic load thresholds can be applied to different traffic types. In this way, the cell selection for initial access is universal.

[0097] Let us then describe some embodiments of the selection logic for cell selection. Figure 7 A flow chart of an embodiment of selection logic for cell selection by a terminal device is shown. The selection logic describes how the terminal device may employ the above table for selecting a cell for initial access. Figure 7, blocks 300 to 304 may be performed in the manner described above. In block 700, the terminal device determines the service type of the data to be transmitted. As described above, the service type may be defined, for example, based on QoS classification, latency requirements, channel identifiers, or data bearer identifiers. If the service type indicates that the data is high priority data, initial access and data transmission may be performed via the first cell that resides (block 308). As described above, if the service type indicates a priority above a certain threshold, for example, in Table 2, the highest priority data service is always sent via the cell that resides.

[0098] On the other hand, if the traffic type indicates low priority traffic, for example, a traffic type that substantially supports access via a sleeping cell in at least one sleeping state, the process may proceed to block 702, where it is determined whether a sleeping cell has been detected for initial access. If no sleep is detected, the process may proceed to block 308 for initial access via a camped cell. If at least one sleeping cell has been detected, the process may proceed to block 704, where a combination of traffic type and sleep state of the detected cell(s) is searched from the initial access configuration, and a cell for initial access is selected based on at least the combination of traffic type and sleep state. If the combination of traffic type and sleep state is mapped to a camped cell in the initial access configuration, the process proceeds to block 308. If the combination of traffic type and sleep state is mapped to a sleeping cell in the initial access configuration, the process may proceed to block 310 and wake up the sleeping cell.

[0099] In the case where there are multiple sleeping cells, the terminal device may select the sleeping cell having the sleeping state that provides the fastest wake-up time. However, another criterion may equally be used to select one of the sleeping cells.

[0100] In addition to the combination of service type and sleep state, additional criteria are defined in the initial access configuration, such as service load or signal strength of sleeping cells and / or resident cells, and the same logic used to use the initial access configuration can be used. For example, if the additional criterion is service load, the terminal device can determine the combination of service type of data, sleep state of sleeping cells and service load of resident cells, and determine whether the initial access configuration maps the combination to sleeping cells or resident cells, and then selects the corresponding cell for initial access. The same logic can be applied to signal strength: the terminal device can determine the combination of service type of data, sleep state of sleeping cells and signal strength of resident cells and / or sleeping cells, and determine whether the initial access configuration maps the combination to sleeping cells or resident cells, and then selects the corresponding cell for initial access.

[0101] In an embodiment, the signal strength of the sleeping cell is measured based on the signal strength of the camping cell and the known position of the access node 104B relative to the access node 104A. As is known in the art, modern communication systems send signals as narrow beams so that the coverage area of ​​the cell is covered by the combined coverage area of ​​multiple such narrow beams. Therefore, the terminal device can use information about the measured beam (e.g., beam identifier, signal strength of the measured beam, and the position of the access node 104B relative to the access node 104A) to determine the distance between the terminal device and the access node 104B.

[0102] Another criterion for cell selection is the mobility of the terminal device. In the case where the mobility is above a threshold (e.g., the speed of the terminal device is above a threshold), the initial access configuration may specify that the terminal device should implement initial access via the camping cell. If the mobility is below the threshold, the wake-up of the sleeping cell may be enabled according to any one of the embodiments described above.

[0103] Although the terminal device performs cell selection, it is preferred that the radio access network or system specification provides an initial access configuration. In this way, the behavior of (multiple) terminal devices is predictable. In an embodiment, before the sleeping cell enters the sleeping state, the terminal device receives the initial access configuration from the sleeping cell. Figure 8 and 9 A signaling diagram showing a process for configuring initial access configuration and initial access. Figure 8 An embodiment is shown in which a sleeping cell sends an initial access configuration before entering a sleeping state, and Fig. 9 An embodiment is shown in which a camped cell sends an initial access configuration and a terminal device receives the initial access configuration from the camped cell.

[0104] refer to Figure 8 , the initial situation is that the terminal device 100 resides in a second cell provided by the access node 104B (step 800). The terminal device may be in an idle state or an inactive state. Upon determining to enter a sleeping state or as part of periodically transmitted system information, the sleeping cell may send an initial access configuration in step 802, for example, via broadcast signaling. Upon receiving the initial access configuration in step 802, the terminal device may store the initial access configuration. Thereafter, the access node 104B may apply the selected sleeping state to the cell, so that the cell becomes a sleeping cell (block 804).

[0105] In an embodiment, the access node 104B sends a wake-up signal (WUS) configuration in step 802 in conjunction with the initial access configuration or as part of a different signaling message, which includes WUS resources (in time / frequency) and / or a WUS sequence that the terminal device can use to send a wake-up signal.

[0106] When detecting that the cell managed by access node 104B has entered the dormant state, the terminal device may perform cell selection and choose to camp on a cell provided by access node 104A (not shown), and the selected cell becomes the camped cell.

[0107] As described above, the sleeping cell may still send a discovery signal including a reference signal and a cell identifier in the sleeping state (step 806). The discovery signal may also include an information element indicating the sleeping state of the sleeping cell. In this way, the terminal device may detect the sleeping state of the sleeping cell in the above embodiment. Another alternative is that the sleeping cell indicates the sleeping state in step 802. Upon receiving the discovery signal, the terminal device may measure the signal strength of the discovery signal in box 808. In some embodiments, the terminal device may also measure the signal strength of the reference signal received from the resident cell of the access node 104A.

[0108] Thereafter, the terminal device performs cell selection in 306 for uplink data to be transmitted. Figure 8 Two options are shown: selecting a sleeping cell in box 810 and selecting a resident cell in box 830. Let's assume that the terminal device selects a sleeping cell, for example, the uplink data is low priority data, such as file transfer. When the sleeping cell is selected in box 810, the terminal device can send a wake-up signal to the sleeping cell in the WUS resources configured by the sleeping cell (step 812). Since the access node 104B is monitoring the WUS resources in the sleeping state, in box 816, the access node 104B receives the wake-up signal and activates the sleeping cell. Box 816 may include powering on at least some circuit systems of the access node 104B for the cell awakened from the sleeping state. The access node 104B can then confirm the wake-up and send system information in step 818. The system information may include certain system information required for the initial access message, such as a random access request. Such information may include, for example, random access resources.

[0109] The access node 104B may also notify neighboring access nodes of its activation in step 820. This information may be provided by Xn / X2 information exchange and coordination between access nodes may be ensured. The terminal device may wait for cell activation before initiating connection establishment (e.g., RRC connection establishment in step 822 via a random access procedure). When the RRC connection is established, uplink data may be sent via the awakened cell and access node 104B in step 824.

[0110] When the resident cell and access node 104A are selected in box 830, for example, when the service type is a high priority service type (such as a video call), the terminal device can implement a regular connection establishment process in step 832 and send uplink data via the resident cell and access node 104A in step 834.

[0111] Fig. 9 Shows the main follow Figure 8 The signaling diagram of the steps of the embodiment of Figure 8 The steps or blocks indicated by the same reference numerals in the drawings indicate the same or substantially similar functions. Fig. 9 The initial situation in the embodiment of is that the terminal device is camped in a cell provided by the access node 104A (step 902), and the access node has put its cell into a dormant state (block 900). In this case, the terminal device can receive an initial access configuration from the camped cell in step 904 and store the initial access configuration. Thereafter, the process can continue in the manner described above.

[0112] Based on the above embodiment, a process for an access node of a cellular communication system is provided. The access node may be an access node 104B managing a sleeping cell or an access node 104A managing a resident active cell. Figure 8 and Fig. 9 After the action of the access node in, the process for the access node may include: obtaining an initial access configuration, which maps the service type with the sleep state and the cell for initial access; sending (e.g., broadcasting) the initial access configuration; and receiving an initial access message and uplink data from the terminal device.

[0113] In an embodiment, the access node triggers entry into a sleep state (eg, a selected sleep state among a plurality of supported sleep states), and in response to the trigger, sends an initial access configuration before entering the sleep state.

[0114] Fig.10 Shown includes for implementation Figure 3 The device may include at least one processor 10 and at least one memory 20 including computer program code (software) 24, wherein the at least one memory and the computer program code (software) are configured to work with the at least one processor so that the device implements Figure 3The process or any one of the above embodiments thereof. The device can be used in a terminal device of a cellular communication system. The device can be a circuit system or an electronic device that implements some embodiments of the present invention in the terminal device. Therefore, the device for performing the above functions can be included in the terminal device, for example, the device can include a circuit such as a chip, a chipset, a processor, a microcontroller or a combination of these circuit systems for the terminal device.

[0115] The memory 20 may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The memory may store a configuration database 26 and computer program code 24 (software) that configures the operation of one or more processors or processing circuit systems of the device. The configuration database may store an initial access configuration whenever the initial access configuration is available or becomes available to the device.

[0116] In an embodiment, the apparatus comprises at least one processor, at least one memory 20 and a processor configured to execute Figure 3 The process or computer program code of any one of its embodiments. At least one processor may include a communication controller 12. The communication controller 12 may include an RRC controller 14, which is configured to establish, manage and terminate a radio connection, such as an RRC connection. The RRC controller 12 may be configured to, for example, establish and reconfigure an RRC connection. The RRC controller may also control the communication of the terminal device in an idle and inactive state, for example by configuring the device to receive and process system information and reference signals from an access node.

[0117] The communication controller 12 may further include a cell selection circuit system 16 configured to implement a cell selection process according to any of the above-described embodiments based on the initial access configuration.

[0118] The apparatus may also include a communication interface 22, which includes hardware and / or software for providing the apparatus with radio communication capabilities, as described above. The communication interface 22 may include, for example, an antenna, one or more radio frequency filters, a power amplifier, and one or more frequency converters. The communication interface 22 may include the hardware and software required to implement radio communications over a radio interface, for example, according to the specifications of an LTE or 5G radio interface.

[0119] FIG. 12 shows an apparatus comprising a processing circuit system (such as at least one processor) and at least one memory 60 including computer program code (software) 64, wherein the at least one memory and the computer program code (software) are configured to, together with the at least one processor, cause the apparatus to implement Figure 8 or Fig. 9The function of access node 104A or 104B in the process of the frame. The device can be configured to implement at least the transmission of the initial access configuration and the reception of the initial access message based on the cell selection caused by the initial access configuration. The device can be used for the access node of the cellular network infrastructure. The device can be a circuit system or electronic device that implements some embodiments of the present invention in the access node. Therefore, the device for implementing the above functions can be included in such a device, for example, the device may include a combination of such circuit systems as a chip, a chipset, a processor, a microcontroller or an access node. In other embodiments, the device is an access node. At least one processor or processing circuit system can implement the communication controller 50 to control the communication with the terminal device through the radio interface in the above manner.

[0120] The communication controller 50 may include an RRC controller 56 configured to establish, manage and terminate a radio connection with a terminal device served by the access node. The RRC controller 56 may be configured, for example, to establish and reconfigure an RRC connection with a terminal device. The RRC controller may implement a random access procedure for establishing an RRC connection and controlling data transmission on the RRC connection.

[0121] The communication controller 50 may also include a cell selection configuration circuit system 54, which is configured to select parameters of the initial access configuration. For example, the cell selection configuration circuit system may be configured to select one or more of the above thresholds. The communication controller may control the transmission of the initial access configuration, for example as part of the broadcasted system information.

[0122] The memory 60 may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The memory 60 may include a configuration database 66 that stores an initial access configuration for the current application.

[0123] The apparatus may also include a radio communication interface 62, which includes hardware and / or software for providing the apparatus with radio communication capabilities with a terminal device, as described above. The communication interface 62 may include, for example, an antenna array, one or more radio frequency filters, a power amplifier, and one or more frequency converters. The communication interface 62 may include the hardware and software required to implement radio communications over a radio interface, for example, according to the specifications of an LTE or 5G radio interface.

[0124] The apparatus may also include another communication interface 68 for communicating toward the core network. The communication interface may support the corresponding communication protocol of the cellular communication system to enable communication with other access nodes, with other nodes of the radio access network, and with nodes in the core network and even outside the core network. The communication interface 68 may include the necessary hardware and software for such communication. For example, step 820 may be performed by the communication interface 68.

[0125] As used in this application, the term "circuitry" refers to one or more of: (a) a hardware circuit implementation only, such as an implementation in analog and / or digital circuits only; (b) a combination of circuitry and software and / or firmware, such as (as applicable): (i) a combination of (multiple) processors or processor cores; or (ii) a portion of (multiple) processors / software comprising (multiple) digital signal processors, software, and at least one memory, which work together to enable the device to perform specific functions; and (c) a circuit system, such as (multiple) microprocessors or a portion of (multiple) microprocessors, that requires software or firmware for operation even if the software or firmware is not physically present.

[0126] This definition of 'circuitry' applies to the use of the term in this application. As another example, as used in this application, the term "circuitry" would also cover an implementation of only a processor (or multiple processors) or a portion of a processor (e.g., one core of a multi-core processor) and its (or their) accompanying software and / or firmware. The term "circuitry" would also cover, for example and if applicable, specific elements of an apparatus according to an embodiment of the present invention, baseband integrated circuits, application specific integrated circuits (ASICs), and / or field programmable gate arrays (FPGAs) circuits.

[0127] Figures 2 to 9 The process or method described in or any embodiment thereof may also be implemented in the form of one or more computer processes defined by one or more computer programs. The computer program may be in source code form, object code form or some intermediate form, and it may be stored in some kind of carrier, which may be any entity or device capable of carrying the program. Such carriers include transient and / or non-transient computer media, such as recording media, computer memories, read-only memories, electronic carrier signals, telecommunication signals, and software distribution packages. Depending on the required processing power, the computer program may be executed in a single electronic digital processing unit, or it may be distributed between multiple processing units.

[0128] The embodiments described herein are applicable to the wireless networks defined above, but are also applicable to other wireless networks. The protocols used, the specifications of wireless networks and their network elements are developing rapidly. Such developments may require additional changes to the described embodiments. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate, not limit, the embodiments. It is obvious to those skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. The embodiments are not limited to the above examples, but may vary within the scope of the claims.

Claims

1. An apparatus for a terminal device, comprising components for performing the following operations: camping on a first cell and detecting a second cell in a sleep state; Obtaining an initial access configuration, wherein the initial access configuration maps a service type with a sleep state and a cell for initial access; acquiring data for uplink transmission; If the service type of the data is the first service type, and the sleep state of the second cell is the first sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending the data via the second cell; If the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is a second sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending the data via the second cell; as well as Under another condition defined in the initial access configuration and based on the traffic type and the sleep state of the second cell, an initial access message is sent to the first cell, and the data is sent via the first cell.

2. The apparatus according to claim 1, wherein the component is configured to: determine the strength of a reference signal received from the second cell when the second cell is in the sleep state; if the strength of the reference signal is higher than a threshold, send the wake-up signal to the second cell; and if the strength of the reference signal is lower than the threshold, send the initial access message to the first cell and send the data via the first cell.

3. An apparatus according to claim 1 or 2, wherein the component is configured to: if the service type is a third service type, send the initial access message to the first cell and send the data via the first cell, and wherein the first service type is associated with a first delay requirement, the second service type is associated with a second delay requirement, and the third service type is associated with a third delay requirement, and the third delay requirement defines a delay requirement that is more stringent than the first service type and the second service type.

4. An apparatus according to any preceding claim, wherein the component is configured to: if the sleep state is a third sleep state, send the initial access message to the first cell and send the data via the first cell, and wherein the first sleep state is associated with a first wake-up delay, the first wake-up delay defining a delay taken for the second cell to wake up from the sleep state, wherein the second sleep state is associated with a second wake-up delay that is shorter than the first wake-up delay, and wherein the third sleep state is associated with a third wake-up delay that is longer than the first wake-up delay and the second wake-up delay.

5. The apparatus according to any preceding claim, wherein the component is configured to: if the traffic type is the second traffic type, and if the sleep state is the first sleep state, send the initial access message and send the data via the first cell.

6. The apparatus according to any preceding claim, wherein the initial access configuration provides at least the following information:

7. An apparatus according to any preceding claim, wherein the component is configured to: determine a traffic load in the first cell, and if the traffic load is above a threshold, send the wake-up signal and the initial access message to the second cell, and send the data via the second cell.

8. An apparatus according to any preceding claim, wherein the component is configured to: determine the strength of a reference signal received from the first cell when the second cell is in the sleep state; if the strength of the reference signal is below a threshold, send the wake-up signal to the second cell; and if the strength of the reference signal is above the threshold, send the initial access message to the first cell and send the data via the first cell.

9. An apparatus as claimed in any preceding claim, wherein at least some communication functions of the second cell are unavailable to the apparatus during the sleep state.

10. An apparatus according to any preceding claim, wherein the initial access message sent to the second cell comprises the wake-up signal.

11. An apparatus according to any preceding claim, wherein the means is configured to receive the initial access configuration from the first cell.

12. The apparatus of any preceding claim, wherein the component is configured to, when the second cell is selected for the initial access, send a wake-up signal to the second cell before sending the initial access message to the second cell.

13. An apparatus according to any preceding claim, wherein the means is configured to receive the initial access configuration from the second cell before the second cell enters the sleep state.

14. An apparatus comprising means for performing the following operations: Obtaining an initial access configuration, wherein the initial access configuration maps a service type with a sleep state and a cell for initial access; Sending the initial access configuration; as well as An initial access message and uplink data are received from a terminal device.

15. The apparatus of claim 14, wherein the component is configured to trigger entry into a sleep state, and in response to the trigger, send the initial access configuration before entering the sleep state.

16. An apparatus according to any preceding claim, wherein said means comprises at least one processor and at least one memory comprising computer program code, said at least one memory and computer program code being configured to, with said at least one processor, cause said execution of said apparatus.

17. A method comprising: The terminal device resides in the first cell and detects the second cell in a sleep state; The terminal device obtains an initial access configuration, where the initial access configuration maps a service type with a sleep state and a cell for initial access; The terminal device obtains data for uplink transmission; If the service type of the data is the first service type, and the sleep state of the second cell is the first sleep state, the terminal device sends a wake-up signal to the second cell, sends an initial access message to the second cell, and sends the data via the second cell; If the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is a second sleep state, the terminal device sends a wake-up signal to the second cell, sends an initial access message to the second cell, and sends the data via the second cell; as well as Under another condition defined in the initial access configuration and based on the service type and the sleep state of the second cell, the terminal device sends an initial access message to the first cell and sends the data via the first cell.

18. The method according to claim 17, further comprising: determining a strength of a reference signal received from the second cell when the second cell is in the sleep state; If the strength of the reference signal is higher than a threshold, sending the wake-up signal to the second cell and sending the initial access message to the first cell; and If the strength of the reference signal is lower than the threshold, sending the data via the first cell.

19. A method according to claim 17 or 18, wherein if the service type is a third traffic type, the terminal device sends the initial access message to the first cell and sends the data via the first cell, and wherein the first service type is associated with a first delay requirement, the second service type is associated with a second delay requirement, and the third service type is associated with a third delay requirement, and the third delay requirement defines a delay requirement that is more stringent than the first service type and the second service type.

20. A method according to any one of the preceding claims 17 to 19, wherein if the sleep state is a third sleep state, the terminal device sends the initial access message to the first cell and sends the data via the first cell, and wherein the first sleep state is associated with a first wake-up delay, the first wake-up delay defining the delay taken for the second cell to wake up from the sleep state, wherein the second sleep state is associated with a second wake-up delay that is shorter than the first wake-up delay, and wherein the third sleep state is associated with a third wake-up delay that is longer than the first wake-up delay and the second wake-up delay.

21. The method according to any one of the preceding claims 17-20, wherein if the service type is the second service type and if the sleep state is the first sleep state, the terminal device sends the initial access message and sends the data via the first cell.

22. The method according to any one of the preceding claims 17-21, wherein the initial access configuration provides at least the following information:

23. The method according to any one of claims 17-22, wherein the terminal device determines the traffic load in the first cell, and if the traffic load is higher than a threshold, sends the wake-up signal and the initial access message to the second cell, and sends the data via the second cell.

24. The method according to any one of the preceding claims 17 to 23, wherein the terminal device: When the second cell is in the sleep state, determining a strength of a reference signal received from the first cell; If the strength of the reference signal is lower than a threshold, sending the wake-up signal to the second cell; If the strength of the reference signal is higher than the threshold, the initial access message is sent to the first cell, and the data is sent via the first cell.

25. A method according to any preceding claim 17 to 24, wherein at least some communication functions of the second cell are unavailable to the terminal device during the sleep state.

26. The method according to any of the preceding claims 17 to 25, wherein the initial access message sent to the second cell comprises the wake-up signal.

27. The method according to any one of the preceding claims 17 to 26, wherein the terminal device receives the initial access configuration from the first cell.

28. The method according to any one of the preceding claims 17 to 27, wherein when the terminal device selects the second cell for the initial access, before sending the initial access message to the second cell, sends a wake-up signal to the second cell.

29. The method according to any one of the preceding claims 17 to 28, wherein the terminal device receives the initial access configuration from the second cell before the second cell enters the sleep state.

30. A method comprising: An initial access configuration is acquired by the access node, where the initial access configuration maps a service type with a sleep state and a cell for initial access; The access node sends the initial access configuration; as well as An initial access message and uplink data are received by the access node from a terminal device.

31. The method of claim 30, wherein the access node triggers entry into a sleep state and, in response to the trigger, sends the initial access configuration before entering the sleep state.

32. A computer program product embodied on a computer readable medium and comprising computer program code readable by a computer, wherein the computer program code configures the computer to implement a computer process comprising: Obtaining an initial access configuration, wherein the initial access configuration maps a service type with a sleep state and a cell for initial access; Sending the initial access configuration; as well as An initial access message and uplink data are received from a terminal device.

33. A computer program product embodied on a computer readable medium and comprising computer program code readable by a computer, wherein the computer program code configures the computer to implement a computer process comprising: camping on a first cell and detecting a second cell in a sleep state; Obtaining an initial access configuration, wherein the initial access configuration maps a service type with a sleep state and a cell for initial access; acquiring data for uplink transmission; If the service type of the data is the first service type, and the sleep state of the second cell is the first sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending the data via the second cell; If the service type of the data is a second service type different from the first service type, and if the sleep state of the second cell is a second sleep state, sending a wake-up signal to the second cell, sending an initial access message to the second cell, and sending the data via the second cell; as well as Under another condition defined in the initial access configuration and based on the traffic type and the sleep state of the second cell, an initial access message is sent to the first cell, and the data is sent via the first cell.

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