CN112602363B

CN112602363B - Method for dynamically allocating paging and/or RACH resources and related equipment

Info

Publication number: CN112602363B
Application number: CN201980055610.2A
Authority: CN
Inventors: 乌莫·萨利姆; 布鲁诺·杰裘克斯
Original assignee: JRD Communication Shenzhen Ltd
Current assignee: JRD Communication Shenzhen Ltd
Priority date: 2018-11-02
Filing date: 2019-10-28
Publication date: 2023-11-14
Anticipated expiration: 2039-10-28
Also published as: GB2578631A; CN112602363A; GB2578631B; GB201817917D0; WO2020088419A1

Abstract

The present application discloses a procedure for providing RACH and paging occasion resources in a cellular radio communication system operating on unlicensed resources. The location of the resource is modified to increase the likelihood that the resource is available during the period of time that the transmission channel access has been obtained.

Description

Method for dynamically allocating paging and/or RACH resources and related equipment

Technical Field

The present application relates to wireless communication systems operating in unlicensed spectrum, and in particular to resource allocation for paging and random access messages.

Background

Wireless communication systems, such as third generation (3G) mobile telephone standards and technologies are well known. Such 3G standards and technologies have been developed by the third generation partnership project (Third Generation Partnership Project,3 GPP). Third generation wireless communications have generally evolved to support macro cellular handset communications. Communication systems and networks have evolved towards broadband and mobile systems.

In a cellular wireless communication system, a User Equipment (UE) is connected to a radio access network (Radio Access Network, RAN) through a wireless link. The RAN includes a set of base stations that provide radio links for UEs located in cells covered by the base stations, and an interface to a Core Network (CN) that provides overall Network control. It is understood that the RAN and CN each perform their respective functions for the entire network. For convenience, the term cellular network will be used to refer to a combination of RAN & CN, and it will be understood that the term is used to refer to the various systems that perform the disclosed functions.

The third generation partnership project has developed a so-called long term evolution (Long Term Evolution, LTE) system, i.e. an evolved universal mobile telecommunications system regional radio access network (Evolved Universal Mobile Telecommunication System Territorial Radio Access Network, E-UTRAN), for mobile access networks in which one or more macro cells are supported by base stations called enodebs or enbs (evolved nodebs). Recently, LTE has evolved further into a so-called 5G or new air interface (NR) system, in which one or more cells are supported by base stations called next generation nodebs (gnbs). NR recommends the use of orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) physical transport formats.

The use of unlicensed spectrum presents particular challenges for cellular systems, particularly with respect to fair sharing of access to transmission media and transmission time. Listen-before-talk (LBT) is used as the basic coexistence mechanism for unlicensed spectrum, so the radio transmitter needs to make clear channel assessment (clear channel assessment, CCA) checks before transmitting. CCA involves at least Energy Detection (ED) with a certain threshold (ED threshold) for a duration to determine whether the channel is occupied or idle. If the channel is occupied, a random back-off (back-off) within the contention window is used so that there is a shortest duration for which the channel is idle before the transmitter can transmit. To protect Wi-Fi ACK transmissions, a delay (defer) time (e.g., 43 μs for optimal traffic) is employed after each busy CCA before resuming backoff. After the transmitter has access to the channel, the transmitter is allowed to transmit only for a limited time, which is called the maximum channel occupancy time (maximum channel occupancy time, MCOT).

A transmitter in a group of devices may access the transmission medium of all devices of the group of devices. For example, a base station may access the transmission medium of all UEs associated with the base station. Each UE may then transmit within the MCOT obtained by the base station according to the appropriate CCA.

To reduce power consumption and shared resources, the UE is configured to listen for messages only in certain windows and transmit only in certain windows. For example, while in idle mode, the UE may sleep and wake up only at intermittent Paging Occasions (POs) to listen for Paging messages indicating that downlink transmissions need to be awakened. Also, when the UE wishes to make uplink transmission, the UE transmits an uplink request to the base station. The request is sent on a random access channel (Random Access Channel, RACH). The RACH transmission can only be made at a specific interval.

Due to the limited duration of MCOT and uncertainty in accessing unlicensed spectrum, it is possible that no PO or RACH window falls within this period, or very far back in this period. This may limit the ability of the UE to communicate with the base station. For example, if the UE has an uplink message, but the MCOT start time and duration are such that it does not cover the RACH window, the UE will not be able to initiate a request to the base station. The UE needs to wait for the next time the base station (or possibly a mobile within the same cell) has obtained access to the unlicensed medium in order to be able to initiate a RACH request on the configured resources. Thus, there is a delay before access to the transmission medium is obtained, and the subsequent RACH window falls within the MCOT. Thus, there may be a large delay in the uplink transmission, which is the same for the downlink, since the PO is delayed during the time period when there is transmission medium access.

Accordingly, there is a need for an improved resource allocation method for unlicensed transmissions.

Disclosure of Invention

Summary some of the concepts are presented in simplified form as further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

An embodiment of the present application provides a method for dynamically allocating paging and/or RACH resources, which is characterized in that the method operates in a cellular radio communication system with unlicensed media, and includes:

at the base station, gaining access to the transmission medium using a listen-before-talk procedure; in the access time period acquired by the base station, carrying out resource allocation for paging occasions and/or RACH transmission; and transmitting a message indicating resource allocation from the base station to a user equipment connected to the base station.

The message may be a broadcast message.

The message may be sent to all user equipments connected to the base station.

The message may be a group public message.

The indication may be sent in a common DCI message.

The common DCI message may be transmitted in a common set of control resources.

The common DCI message may be transmitted at the beginning of a period of time when access has been obtained.

The at least one user equipment may be configured to listen for a common DCI message on a specific resource with a defined period.

The at least one user equipment may be configured to listen for the common DCI message at least one time interval relative to its paging occasion and/or RACH occasion.

The at least one user equipment may be configured to listen for the common DCI in a defined subframe of the frame in which its paging occasion and/or RACH occasion is located.

The indication message may be a synchronization sequence block together with a synchronization signal, wherein the indication of the resource is encoded.

The embodiment of the application also provides a method for dynamically allocating paging and/or RACH resources, which is characterized in that the method works in a cellular wireless communication system with unlicensed media, and comprises the following steps:

receiving, at a user equipment, a message from a base station connected to the user equipment, the message indicating a paging occasion and/or a resource allocation of RACH transmission during a period of access acquired by the base station; and receiving, at the user equipment, a paging message or RACH transmission using the indicated resources.

The message may be a broadcast message.

The message may be sent to all user equipments connected to the base station.

The message may be a group public message.

The message may be a common DCI message.

The common DCI message may be received in a common set of control resources.

The common DCI message may be received at the beginning of a period of time when access has been obtained.

The user equipment may be configured to listen for the common DCI message on a specific resource with a defined period.

The user equipment is configured to listen for a common DCI message at least one time interval relative to its paging occasion and/or RACH occasion.

The user equipment may be configured to listen for a common DCI message in a defined subframe of a frame in which its paging occasion and/or RACH occasion is located.

The message may be a synchronization sequence block in which the indication of the resource is encoded.

The embodiment of the application also provides a base station configured to execute the method.

The embodiment of the application also provides user equipment configured to execute the method.

Drawings

Further details, aspects and embodiments of the application are described by way of example and with reference to the accompanying drawings. Elements in the figures are illustrated in a simplified and clear manner and are not necessarily drawn to scale. The same reference numerals have been included in the various figures for ease of understanding.

Fig. 1 is a schematic diagram of an example cellular wireless communication network.

Detailed Description

Those skilled in the art will recognize and appreciate that the specifics of the examples are described merely to illustrate some embodiments and that the teachings herein are applicable in a variety of alternative contexts.

Fig. 1 shows a schematic diagram of three base stations (e.g., enbs or gnbs, depending on the particular cellular standard and terminology) forming a cellular network. Typically, each base station will be deployed by one cellular network operator to provide geographic coverage for UEs in that region. The base stations form a radio area network (Radio Area Network, RAN). Each base station provides wireless coverage for UEs in its area or cell. The base stations are interconnected by an X2 interface and connected to the core network by an S1 interface. It will be appreciated that only the basic details are shown in order to illustrate the main features of the cellular network.

Each base station includes hardware and software for implementing RAN functions, including communication with the core network and other base stations, control and data signaling between the core network and UEs, and maintaining wireless communication of UEs associated with each base station. The core network includes hardware and software that implements network functions such as overall network management and control, and routing of calls and data.

When a base station is communicating with a device (e.g., a mobile user or other device) using an unauthorized medium, it must obtain the right to transmit on the unauthorized medium. Provision is made to allow both the base station and the mobile to perform CCA to obtain channel access, however, typically the base station will perform CCA and the user will only perform CCA after their base station is configured. The time when the base station gets access to the transmission medium (either for its own transmission or for the relevant UE transmission) is random, related to the system time. This occurs because many different networks and devices may share unauthorized resources with different times and usage intervals. After gaining access, the periodic resources therefore cannot provide reliable transmission opportunities in the MCOT. Therefore, conventional periodic PO and RACH windows cannot be relied upon. It is even possible that if MCOT is smaller than the PO/RACH period, the network and the UE cannot communicate because there is no transmission opportunity. For convenience, the period of time that the base station & its UE can access the transmission medium will be referred to as a transmission opportunity (Transmission Opportunity, txOP).

The following embodiments provide methods and processes for ensuring that transmission opportunities exist when channel access is available. The PO and RACH windows are dynamically configured according to system status and/or channel access acquisition.

In an embodiment, multiple RACH configurations may be defined and the network may instruct the UE to select a particular configuration to use during TxOP. For example, the first configuration may provide RACH occasions in specific time-frequency resources in each third subframe. The second configuration may be that RACH occasions occur in a third subframe, a sixth subframe and a ninth subframe in certain time-frequency resources. The base station may then send an indication of which configuration to use. The configuration may be semi-static or may be applied only to the current (or set of) txops. In this simple embodiment, a 1-bit signal to a user or group may indicate whether configuration 1 or configuration 2 is in an active state in the current TxOP. The same principle applies to PO.

In an embodiment, the default configuration of the PO and RACH resources may be in an active state unless otherwise specified. The configuration may be overridden or changed to other configurations if deemed necessary by the base station. Such a procedure may reduce control signaling because messages are only needed when the default configuration is changed. The base station typically gains access to the transmission medium on behalf of all relevant UEs, so the problem of the base station knowing when a window falls outside the TxOP occurs. The base station can thus properly control the PO and RACH resources.

The current system state may be used to select the appropriate configuration. For example, if there are a large number of idle mode UEs in a cell, few active users, the base station may increase the resources available for the POs to maximize the base station's ability to page idle mode UEs. Likewise, if there are a large number of active UEs frequently making uplink transmissions, RACH resources may be increased to increase the probability that the UE can make RACH transmissions in TxOP.

Common, or group common, signaling may be used to transmit resource configurations to the UE to control the signaling overhead of reconfiguring resources.

A set of RACH configurations and a set of PO configurations may be defined. The combination of these configurations may be allocated one reference each so that the base station may indicate the configuration to be used to the UE by transmitting the reference. This may reduce control overhead. In an embodiment of two RACH configurations and two PO configurations, all combinations may be indicated by a 2-bit field. Likewise, separate references may be used to indicate each RACH and PO configuration.

The configuration indication may be sent in a common DCI message, which may reduce signaling overhead. The common DCI may be transmitted at the beginning of a TxOP in a common COntrol REsource SET (CORESET) so that each UE receives REsource indications of the PO and RACH early in each TxOP.

If the carrier in the unlicensed spectrum is used as a TDD carrier, which is in fact the typical duplex mode of the unlicensed spectrum, the base station may need to use the slot indication format (Slot Indication Format, SFI) field of the DCI to indicate UL-DL split. Other information may also be included in the common DCI, for example, control information on resources or TxOP duration, so TxOP may be effectively utilized.

To receive common DCI, idle UEs need to monitor the relevant common CORESET when it can transmit according to the configuration sent by the base station. This may increase the power consumption of the idle mode UE relative to operating with the licensed carrier, since the idle mode UE will not monitor any such DCI, but will only monitor for paging indications at paging occasions. Another problem in unlicensed media is uncertainty, where UEs may not know in advance when their base stations can access the media. Thus, if the base station does not have access, the UE may wake up often to listen to the common DCI, but such common DCI is not transmitted. To avoid monitoring DCI in each such case, the UE may be configured to listen for common DCI (carrying paging/RACH resource indication) on specific resources with a certain periodicity. In an embodiment, the UE may be configured to listen to the common DCI only once at a specific time associated with the corresponding PO. For example, if the UE is configured to page in the third subframe of every second frame, it may listen to the common DCI in the fifth and eighth subframes of the frame with the PO. Different configurations may be selected in order to cover the network and UE requirements for mutual communication.

In another arrangement, the UE may be configured to listen to the common DCI at a particular time after its PO or RACH resources. This arrangement is particularly applicable to RACH. Before RACH transmission, typically, UEs perform CCA, which may indicate that an unlicensed medium is currently being used by another group of devices if they find the medium busy. So they may be configured to listen to the common DCI after such an unavailable RACH occasion where the base station may send the newly allocated RACH resources.

If configured in a semi-static or dynamic manner, the location of paging and RACH resources may be fixed relative to LBT success time or may be selected from a predefined set of configurations. For example, a reference to a certain set of values may be transmitted for use by the UE to retrieve the desired configuration from the predefined options.

After the base station gains access to the transmission medium, the common DCI carrying the PO/RACH indication may be sent at the beginning of a transmission burst (burst) on an unlicensed carrier (COT or TxOP start). From a detection point of view, the advantage of sending an indication at the beginning of a TxOP is that if there is an SSB, preamble signal or other signal at the beginning of the burst, the UE will decode the common DCI at about the same time and have a better channel estimate because of the other signal. Another advantage of using common DCI at the beginning of the burst is that resource information is available at the beginning of the TxOP and thus before the actual resources appear. This allows the UE sufficient time to listen for pages or RACH transmitted on the newly allocated resources.

In another embodiment, the PO and RACH resources may be indicated in a synchronization sequence block (Synchronization Sequence Block, SSB), which are part of the discovery reference signal (Discovery Reference Signal, DRS) of an unlicensed carrier. SSB will be sent at the beginning of TxOP. The SSB provides time-frequency synchronization through PSS, SSS and transmission of a Master Information Block (MIB) in the PBCH, generally providing cell identity (cell ID), complete time information and necessary control information so that the Remaining Minimum System Information (RMSI) can be found. Because of the very precise structure of the SSB and the importance of the (initial) synchronization, it is preferable not to modify the payload of the SSB. However, limited information may be indicated by indirectly modulating or modifying the information field. For example, DMRS sequence initialization of the PBCH may be modified. Currently, the DMRS sequence initializes partial information of SSB indexes of 8 to 64 beams and transmits the SSB indexes and field indications of 4 beam settings.

The connected mode UE will typically listen to SSB and common DCI and thus may utilize any of the above embodiments to provide PO/RACH information. However, the idle mode UE may sleep without listening to each SSB. In addition, idle mode UEs in a sleep state should not decode DCI. Therefore, the UE requiring the idle mode to monitor SSB or common DCI may reduce sleep time of the UE and increase power consumption. However, an idle mode UE does listen to SSBs (or DRSs) around its PO wakeup time to obtain updated synchronization and channel estimation. For unauthorized transmission resources, the UE may also attempt to determine whether the base station may have access to an unauthorized transmission medium before its wake-up time. Providing PO/RACH indication in SSB may also be applicable to idle mode UEs.

To reduce power consumption of idle mode UEs, the UE may be configured to only listen to the common DCI indicating the PO/RACH resources. The idle mode UE may be configured to decode the common DCI very close to its configured wake-up time, preferably slightly in advance. If the common DCI is only sent at the beginning of the TxOP, the idle mode UE must be configured to decode this common DCI only in the scenario where it must wake up in accordance with its configured DRx cycle.

To alleviate the decoding burden of the common DCI carrying the PO/RACH resources, the common DCI may be repeated multiple times in the TxOP. This increases the probability that the common DCI reaches the UE for the normal listening duration. Repeated transmissions may also improve the reliability of UEs (idle and connected) that receive more than one transmission of a message. The repeated transmission also ensures UEs that miss the TxOP start.

One way to alleviate the burden of idle mode users to decode common DCI at the beginning of the COT may be to transmit common DCI carrying updated paging and RACH resources multiple times in the COT. This will enable users in idle mode to decode the common DCI without increasing the wake-up time. Repeated transmission of common DCI may have reliability advantages for all connected and idle mode users. The UE may miss the start of the TxOP and may not decode the common DCI transmitted at the start. However, the UE may receive repeated transmissions and thus may receive the PO/RACH configuration information.

For an unlicensed system that uses a preamble at the beginning of its TxOP, other methods may be selected to dynamically indicate paging/RACH resources. In this method, paging/RACH resources preconfigured by a base station are offset in time with respect to the start of TxOP. The offset may be equal to the time difference between a certain reference system time and the start of TxOP. In one embodiment, the offset may be the time between subframe 0 of the system time and the beginning of the first subframe in the TxOP. Thus, all paging and RACH resources will be offset by the offset in the TxOP, which is the offset of the TxOP with respect to system time. This approach may be interesting because it allows dynamic allocation and management of paging and RACH resources without any dynamic signaling. The method works when the UE should listen to the preamble that provides it with an indication about the start of the TxOP. This approach may be used when the base station is using some other technique, such as SSB signaling, DRS signaling, or some other suitable signaling, to inform the user about the start of the TxOP, without the need for a preamble.

Thus, the present application allows for the definition of PO and RACH resources within a TxOP to increase the chances of communicating during the TxOP. Such a system can alleviate the difficulties caused by using LBT procedures to obtain unpredictable start times for txops in systems that transmit medium access. The time and/or resources of each PO and RACH may be modified independently or in combination.

The signal processing functions of embodiments of the present application, particularly for the gNB and the UE, may be implemented using a computing system or architecture known to those skilled in the relevant art. Computing systems such as desktop, laptop or notebook computers, hand-held computing devices (PDAs, cell phones, palmtops, etc.), mainframes, servers, clients or any other type of special or general purpose computing device suitable for a given application or environment may be used. The computing system may include one or more processors, which may be implemented using a general purpose or special purpose processing engine, such as a microprocessor, microcontroller, or other control module.

The computing system may also include a main memory, such as Random Access Memory (RAM) or other dynamic memory, for storing information and instructions to be executed by the processor. Such main memory may also be used for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor. The computing system may also include a Read Only Memory (ROM) or other static storage device for storing static information and instructions for the processor.

The computing system may also include an information storage system, which may include, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a Compact Disk (CD) or Digital Video Drive (DVD) read-write drive (R or RW), or other removable or fixed media drive. Storage media may include, for example, hard disk drives, floppy disks, magnetic tape, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by a media drive. The storage medium may include a computer-readable storage medium having stored therein specific computer software or data.

In alternative embodiments, the information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include, for example, removable storage units and interfaces such as cartridge and disk interfaces where programs are stored, removable memory (e.g., flash memory or other removable memory modules) and storage slots, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage units to the computing system.

The computing system may also include a communication interface. Such communication interfaces may be used to allow software and data to be transferred between the computing system and external devices. Examples of communication interfaces may include modems, network interfaces (e.g., ethernet or other NIC cards), communication ports (e.g., universal Serial Bus (USB) ports), PCMCIA slots and cards, etc. Software and data transferred via the communications interface are in the form of signals which may be electronic, electromagnetic, optical or other signals capable of being received by the communications interface medium.

In this specification, the terms "computer program product," "computer-readable medium," and the like may be used to generally refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor, including a computer system, to cause the processor to perform specified operations. Such instructions 45, often referred to as "computer program code" (which may be grouped in the form of computer programs or other groupings), when executed, enable the computing system to perform functions of embodiments of the present application. Note that the code may directly cause the processor to perform specified operations, be compiled to perform specified operations, and/or be combined with other software, hardware, and/or firmware elements (e.g., libraries for performing standard functions) to perform such operations.

The non-transitory computer readable medium may include at least one of the group consisting of: hard disk, CD-ROM, optical storage, magnetic storage, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory. In embodiments where some element is implemented using software, the software may be stored in a computer readable medium and loaded into a computing system using, for example, a removable storage drive. The control module (in this example, software instructions or executable computer program code) when executed by a processor in a computer system causes the processor to perform the functions of the application as described herein.

Furthermore, the inventive concept may be applied to any line performing signal processing functions within a network element. It is further contemplated that, for example, a semiconductor manufacturer may employ the inventive concepts in the design of a microcontroller such as a Digital Signal Processor (DSP) or an Application Specific Integrated Circuit (ASIC) and/or any other independent device of subsystem elements.

It will be appreciated that for clarity, the above description has described embodiments of the application with reference to a single processing logic. However, the inventive concept may equally be implemented by a plurality of different functional units and processors to provide a signal processing function. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Aspects of the application may be implemented in any suitable form including hardware, software, firmware or any combination of these. The application may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors or configurable module components such as FPGA devices.

Thus, the elements and components of an embodiment of the application may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. Although the present application has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the application is limited only by the appended claims. In addition, while a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the application. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. In addition, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Also, the inclusion of a feature in one claim category does not imply a limitation to this category but rather indicates that the feature is equally applicable to other claim categories, as appropriate.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed and in particular the order of individual steps in a method claim does not imply that the steps must be performed in that order. Rather, the steps may be performed in any suitable order. In addition, singular references do not exclude a plurality. Thus, references to "a", "an", "first", "second", etc. do not preclude a plurality.

Although the present application has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the application is limited only by the appended claims. In addition, while a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the application. In the claims, the term "comprising" does not exclude the presence of other elements.

Claims

1. A method of dynamically allocating paging and/or RACH resources in a cellular radio communication system operating on an unlicensed medium, the method comprising:

at the base station, gaining access to the transmission medium using a listen-before-talk procedure;

in the access time period acquired by the base station, carrying out resource allocation for paging occasions and/or RACH transmission, wherein the paging occasions and the RACH window are dynamically configured according to the system state and/or channel access acquisition; the dynamically configuring paging occasions and RACH windows according to system status includes: in response to the increase of idle user equipment, increasing resources for paging occasions; in response to the active user equipment increasing, increasing RACH resources; the dynamically configuring paging occasions and RACH windows according to channel access acquisition includes: defining a plurality of PO and/or RACH configurations and the network instructs the user equipment to select to use a particular configuration during a transmission opportunity; and

and transmitting a message indicating resource allocation from the base station to a user equipment connected to the base station, wherein the indication is transmitted in a common DCI message.

2. The method of claim 1, wherein the message is a broadcast message.

3. The method according to claim 2, characterized in that the message is sent to all user equipments connected to the base station.

4. The method of claim 1, wherein the message is a group public message.

5. The method of claim 1, wherein the common DCI message is transmitted in a common set of control resources.

6. The method of claim 1 or claim 5, wherein the common DCI message is sent at the beginning of a period of time when access has been obtained.

7. The method of claim 1, wherein at least one user equipment is configured to listen for a common DCI message on a specific resource with a defined period.

8. The method according to claim 1, characterized in that at least one user equipment is configured to listen for common DCI messages at least one time interval relative to its paging occasion and/or RACH occasion.

9. The method according to claim 8, characterized in that the at least one user equipment is configured to listen for common DCI in defined subframes of a frame in which its paging occasion and/or RACH occasion is located.

10. The method of claim 1, wherein the indication message is a synchronization sequence block with a synchronization signal, wherein the indication of resources is encoded.

11. A method of dynamically allocating paging and/or RACH resources in a cellular radio communication system operating on an unlicensed medium, the method comprising:

receiving, at a user equipment, a message from a base station connected to the user equipment, the message indicating a paging occasion and/or a resource allocation of RACH transmission during a period of access acquired by the base station, wherein the paging occasion and RACH window are dynamically configured according to a system state and/or channel access acquisition; the dynamically configuring paging occasions and RACH windows according to system status includes: in response to the increase of idle user equipment, increasing resources for paging occasions; in response to the active user equipment increasing, increasing RACH resources; the dynamically configuring paging occasions and RACH windows according to channel access acquisition includes: defining a plurality of RACH configurations and the network instructs the user equipment to select a particular configuration to use during a transmission opportunity; and

at the user equipment, a paging message is received or RACH transmission is made using the indicated resources, wherein the message is a common DCI message.

12. The method of claim 11, wherein the message is a broadcast message.

13. The method according to claim 12, characterized in that the message is sent to all user equipments connected to the base station.

14. The method of claim 11, wherein the message is a group public message.

15. The method of claim 14, wherein the common DCI message is received in a common set of control resources.

16. The method of claim 11 or 15, wherein the common DCI message is received at the beginning of a period of time when access has been obtained.

17. The method of claim 11, wherein the user equipment is configured to listen for the common DCI message on a specific resource with a defined period.

18. The method according to claim 11, characterized in that the user equipment is configured to listen for common DCI messages at least one time interval relative to its paging occasion and/or RACH occasion.

19. The method according to claim 18, characterized in that the user equipment is configured to listen for common DCI messages in defined subframes of the frame in which its paging occasion and/or RACH occasion is located.

20. The method of claim 11, wherein the message is a synchronization sequence block, wherein the indication of resources is encoded.

21. A base station comprising a transmitter configured to perform the method of any of claims 1 to 10.

22. A user equipment comprising a memory and a processor coupled to each other, the processor being configured to perform the method of any one of claims 11 to 20 by means of program instructions stored in the memory.