CN111466142A - Paging system - Google Patents

Abstract

A method of paging user equipment, UE, in a cellular wireless communication system, a paging message may indicate the UE to be paged using a group indication and using individual UE identities. To reduce erroneous access requests, non-paged UEs in the indication group may be indicated as not paged.

Description

Paging system

Technical Field

The present invention relates to a system and method for paging User Equipment (UE) in a cellular wireless network, and more particularly to a method for use with beam scanning.

Background

Wireless communication systems, such as third generation (3G) mobile telephone standards and techniques are well known. The 3G standards and technologies were developed by the Third Generation Partnership Project (3 GPP). Third generation wireless communications were developed to support macro cellular mobile telephone communications. Communication systems and networks are evolving towards broadband mobile systems.

The third generation partnership project developed a so-called long Term Evolution (L TE, &lttttranslation =' L "&tttl &ltt/t &tttong Term Evolution), i.e. Evolved Universal terrestrial Radio Access Network (E-UTRAN), one or more macrocells in a Mobile Access Network are supported by a base station eNodeB or eNB (Evolved NodeB). recently, L TE further Evolved towards a so-called 5G or NR (New Radio technology) system, one or more macrocells in the system are supported by a base station gNB.

In a cellular radio system, radio coverage is provided by a set of base stations, each covering a "cell". UE can roam freely between these cells (free to roam.) in order to reduce power consumption of the UE and improve radio resource utilization, the UE may not be in continuous communication with the base stations although the UE remains connected to the P L MN.

Thus, these standards implement a paging procedure (paging procedure) in which the base station transmits a paging signal. The UE is configured to listen to the paging signal at a specified time interval. If a particular UE receives and decodes a signal, the UE "wakes up" and establishes a communication link with the appropriate base station, e.g., using a random access procedure.

The base station may configure a beam scanning antenna or an antenna panel (antenna) that allows only a signal to be directed in a specific direction, so that radio resource efficiency and coverage can be improved. However, since the location of each UE is unknown, paging signals must be transmitted on all beams of a given cell, even if the UE is located on at most one of the beams. Thus, paging in a beam scanning system may increase paging overhead.

Therefore, when implementing a paging system in a beam scanning scenario, it is desirable to provide a system to reduce the overhead generated.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are 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.

The invention provides a method for paging User Equipment (UE) in a cellular wireless communication network, which comprises the following steps: transmitting a paging indication from the base station to indicate an available paging message; transmitting a paging message, the paging message comprising a group indication and at least one UE indication, the group indication indicating at least one UE group to which the paging message applies, each UE indication indicating a paged UE to which the paging message applies, the at least one UE indication comprising an identity of the paged UE.

The group indication of at least one group may be constituted by a bitmap.

The base station may employ a beam scanning transmission method, and the paging message is transmitted on all beams of the beam scanning transmission method.

The paging message may further include at least one non-paged UE indication, each non-paged UE indication indicating a non-paged UE in at least one paged UE group to which the paging message is not applicable, the non-paged UE indication including an identity of the non-paged UE.

The identity of the at least one paged UE and/or the at least one non-paged UE may be the S-TMSI or IMSI of the UE.

The method may further comprise: a paging format indicator is transmitted from a base station.

The paging format indicator may include an indication of a paging message including the group indication.

The paging format indicator may be transmitted in a paging DCI or a paging message.

The paging message may be a paging message associated with the paging format indicator.

The method may further comprise: an indication of the UE group to which a subsequent paging indication can be applicable is transmitted in the paging DCI.

The paging message may have a fixed format, the group indication is located at a fixed location in the paging message, and the at least one UE indication is located after the group indication.

The method may further comprise: and indicating a UE group to which at least one paging message is not applicable in the paging DCI transmitted by the base station.

The method may further comprise: allocating at least one general P-RNTI and at least one group common P-RNTI to at least one UE; scrambling a paging indication message with the group common P-RNTI so that only UEs assigned to the group common P-RNTI can decode the paging indication.

The number of groups that the UE groups may remain static or semi-static.

The invention also provides a method for processing paging messages, which is executed by UE on the basis of messages received by a base station in a cellular wireless communication network, and comprises the following steps: receiving a paging message; determining whether the UE is in a paged UE group indicated by the message; determining whether the UE is also identified as an unpanded UE in the group of UEs.

The UE may be further identified by an identifier of the UE.

The identifier may be the S-TMSI or IMSI of the UE.

If the UE is not in the indicated paged UE group and is not paged by its UE ID alone, or if the UE is in the paged group and the UE is also indicated as not paged, the UE may return to sleep mode.

The non-transitory computer readable storage medium may include at least one of a hard disk, a Compact disc Read Only Memory (CD-ROM), an optical Memory, a magnetic Memory, a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable Read Only Memory (EEPROM), and a Flash Memory.

Drawings

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Elements in the figures have been simplified and are not necessarily drawn to scale. For ease of understanding, reference numerals have been included in the various figures.

Fig. 1 is a schematic diagram of a decision tree for receiving paging signals.

Detailed Description

In a L TE Paging system, a UE in an idle state wakes up at a Paging Occasion (PO) defined in a Paging Frame (PF) and monitors the PDCCH to check a Paging Indication (PI), if an indication is received about the UE, a related Paging Message (PM) transmitted on the PDSCH is decoded to determine whether the PI points to all UEs configured at the determined PO for the particular UE, so the indicated PM is not applicable for all UEs to decode PM based on the received PI, the PF is a radio Frame that may contain one or more POs, the PO and PF of each UE are derived from the UE-ID and current network configuration (DRX cycle and parameters nB) so that the UEs may be distributed across POs, in a Common Search Space (C-SS, Common Space), the PDCCH scrambled with the P-RNTI is used to schedule the UE, and for subsequent versions of L TE (tracking versions) all UEs are sent in a given region where the same PM is tracked by an eNB (eNB).

When performing beam scanning, PI & PM should be repeated on each beam, since the exact location of the UE is not known. This results in an increase in UE power consumption (the UE needs to wake up at the PO of each beam, with different times of wake up) and an increase in paging overhead due to repetition.

Various mechanisms (mechanisms) are listed below to reduce paging overhead in static systems and beam scanning systems, which may also save power consumption and reduce UE false alarms (false alarms).

The most appropriate paging mechanism may vary depending on network configuration and deployment. To achieve flexibility, a Paging Format Indicator (PFI) is added to Paging DCI (DCI scrambled with P-RNTI). The PFI indicates the paging technique to be used, in particular the PM format that the UE can expect. The following options may apply to PM content (content): -

1. Paging group indication (paging group indication)

UE-ID (S-TMSI or IMSI) indication

3. Combination of group indication and UE-ID

4. Compressed UE-ID

The PFI may use any suitable format. Furthermore, the PFI may be located in a fixed location in the PM, rather than in the DCI.

Rather than identifying individual UEs in the PM, UEs may be grouped and an indication of which groups are being paged is included in the UE. The use of a group indication may significantly shorten the PM length, since the group indication may be much shorter than the UE-ID used to identify a particular UE.

While this reduces the amount of data transmitted in the PM (possibly very significantly), it may also increase the number of UEs that initiate the access procedure when it is not needed. It is unlikely that every UE in the group will be paged, but all UEs in the indicated group receive a PM, which will initiate the access procedure, since the PM appears to be intended for all UEs. Erroneous access procedures generate network overhead, but these techniques can quickly end erroneous access requests, thereby minimizing impact. Furthermore, the reduction in PM length is significant, so the overall effect is beneficial to the network.

The paging group indication may be in the form of a bitmap, with each bit of the indication corresponding to a group.

One way to associate a UE with a paging group is through some deterministic computation (deterministic computation) and employs some or all of the following parameters: UE ID, cell ID, and system information. One way to associate a UE with a group is to use the UE ID (IMSI or S-TMSI) modulo (modulo) group number.

As in option 3 described above, the group indication may be used in combination with the indication of the respective UE. For example, if a group contains only one UE (or a small number of UEs) to be paged, it may be more efficient to explicitly identify the UE than to identify the group. Thus, the network can balance the paging overhead against the impact of false pages and choose the most appropriate balance. This balancing may take into account group size (groups), cell size, number of beams, user density, and network dynamics above. Although the number of groups in a cell may change dynamically, it is relatively complex, since the group/UE association has to be updated dynamically from all affected UEs. Therefore, it is preferable to keep the number of groups in a cell semi-static (semi-static).

The PFI (in the DCI or in the PM itself) may indicate that the PM contains a mix of group indications and individual UEs. Alternatively, the PM may be in a fixed format, the group indication is located at a set position, the rest of the PM includes the UE-ID, and the total length of the PM is determined by DCI. This avoids that the gNB has to indicate the PM format. This fixed location assignment of the paging group indication within the paging message enables all users to understand the content of the paging message without any further signaling. Therefore, the PFI type flag (style flag) is not required in this case.

One improvement example that can be achieved, consider a system with 1000 UEs that are assigned to a particular PO in a cell with 64 beams, requiring paging of 50 of them.

For the conventional method, the length of the paging message is 2000 bits (50 UEs x 40 bits/UE), so that the total paging message load is 64 beams x 2000-128 kbit.

In the above technique, the UEs may be divided into 50 groups of 20 UEs each. For example, each of 10 groups carries (carry)4 UEs to be paged, and each of 10 groups carries one UE to be paged, thereby providing 20 active groups (active groups) for the PO.

The network decides to page 10 groups with multiple UEs on a group basis (50 bits total for group indication) and pages the other 10 UEs individually. Thus, the total PM load is (50+ (10 × 40)) × 64 ═ 28.8kbit (compare 128kbit above). In the group indication, 60 UEs out of 10 × 6 UEs will erroneously start the access procedure.

In another example, the number of groups may be increased to 200, with 5 users per group. Of the 50 UEs to be paged, 12 groups each carry 3 UEs and 14 groups each have 1 UE, providing 26 active groups. The total PM load here is 200 (group bitmap) +14x 40 760bit x 64 beams 48.64kbit, where 12x 2 24 UEs are paged in error. Thus, careful selection of the number of groups and the group size can have a very significant impact on the overall paging load and false paging alarms.

Assuming that at least one UE in the paged group is not paged, there will be at least one erroneous access attempt. To avoid false attempts, the PM may also include the UE-ID in the indicated non-paged group. Thus, if most users in the group are to be paged, the gNB may indicate that the group is paged. To reduce false paging alarms for non-paged UEs in the group (marked as paged by the group in the PM), the gNB may also explicitly add these UE IDs in the PM. When a UE finds that its group is paged in the PM and its UE ID also appears in the PM, the UE concludes that it is not actually paged and takes no further action. Using the logic shown in fig. 1, this technique may reduce the number of erroneous access requests.

At 10, the UE receives a paging message and determines at 11 whether the UE is in a paged group. At 12, if the UE is not in the paged group, the UE checks whether it is explicitly identified and determines whether the UE is paged at 13 or not paged at 14. If the UE determines that it is in the paged group, the UE checks whether it is explicitly identified in the PM at 15. If the UE is explicitly identified, it indicates that the UE has not been paged, as shown at 16. If the UE is not explicitly identified, the UE is paged at 17.

The effect of this logic is that the non-paged UEs in the paged group do not attempt an access request, thereby preventing erroneous access requests. Assuming that more than half of the UEs in the group are paged with the group indication, the overhead of including the negative indication (negative indication) is less than the overhead of explicitly identifying all paged UEs (not using the group). This reduces PM load and avoids erroneous access attempts. This approach allows the base station (or the gNB) to reduce false paging alarms at the expense of some extra paging load (ID of the un-paged UE). The gNB does not have to reduce the false paging alarm to zero, but the proposed scheme allows the gNB to select the appropriate paging load and acceptable rate of false paging alarms at each paging occasion according to the system parameters, including the number of users in the cell, the number of users configured in the PO, and the number of paged UEs.

The UE group may also be indicated in the paging DCI instead of a common paging indication (common paging indication) that triggers all users to configure to decode the paging message at a specific PO to confirm whether or not to be paged. The DCI may include an indication of the active groups such that only these groups remain awake (awake) to receive and decode the PM, and all other groups may return to DRX immediately after paging the DCI. The group indication may be a bitmap or any suitable encoding that may transmit the request information in a small size available space (small size available) of the paging DCI. Size limitations in DCI can penalize a large number of bits in paging DCI for group indication. Thus, a reduced number of groups may be indicated in the paging DCI, and only UEs associated with the active group decode PMs associated with the paging DCI. Then, for super active groups (active super groups) combined with UE ID based paging, the PM may have a large number of group or finer granularity (fine granularity) group indications. This technique provides multi-layer grouping, a first stage in the paging DCI that saves power for members of the inactive group, and a second stage that reduces overhead and false alarms as described above.

For flexible load paging messages carrying both paging group indication and UE ID, the transmitted data can be reduced by compressing the UE-ID, thereby further reducing the overhead of the paging messages. This compression reduces the data required, although there is little risk of compressing two UE-IDs to the same value and thus creating ambiguity. Even if in this case both UEs initiate access attempts, one of them is wrong and rejected.

In a conventional approach, a single paging RNTI (P-RNTI) is used to scramble the PI on the PDCCH, so all UEs scheduled at a particular PO receive the PI, attempting to read the paging message.

The network may have a predefined pool of RNTIs that serves as a group common P-RNTI, which all UEs may know in advance. The UEs may be associated with the group in any suitable manner, such as based on the UE-ID, or based on a combination of the UE-ID and other system information (e.g., cell ID, SFN, or PO number).

This approach of grouping common P-RNTIs may be equally attractive for non-beam scanning applications (acquisition). In the conventional approach, all UEs assigned to a PO listen and decode the PM even if the PM is only for a single UE. Allocating one general RNTI and one group common RNTI for each UE may significantly save energy. Another advantage of multiple group common P-RNTI is that the paging capacity (capacity) of dense cells can be increased. However, the generic P-RNTI is more attractive in case the PM is directed to all or most UEs in the cell, e.g. when the PM involves a change of system information (change).

Although the foregoing description has specifically referred to beam scanning systems, the present invention also relates to non-beam scanning systems.

Although not shown in detail, any device or apparatus forming part of a network may comprise at least a processor, a memory unit and a communication interface, wherein the processor unit, the memory unit and the communication interface are configured to perform the following method: any aspect of the present invention. Further, the options and selections are as follows.

The signal processing functions in the embodiments of the present application, particularly the signal processing capabilities of the gNB and the UE, may be implemented by computing systems or architectures that are well known to those skilled in the art. The computing system may be a desktop, laptop or notebook computer, hand-held computing device (PDA, cell phone, palmtop, etc.), mainframe, server, client, or any other type of special or general purpose computing device as may be satisfactory or applicable to a given application or environment. The computing system may include one or more processors that may execute a general or special purpose processing engine such as, for example, a microprocessor, microcontroller or other control module.

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

The computing system may also include an information storage system including, 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 drive (CD) or Digital Video Drive (DVD) read-write drive (R or RW), or other fixed or removable media drive. The storage medium may include, for example, a hard disk, floppy disk, magnetic tape, optical disk, CD, DVD, or other fixed or removable medium that is read by and written to by a media drive. The storage media may include a computer-readable storage medium having stored thereon particular 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. These components may include, for example, a removable storage unit and interface, such as a program cartridge and cartridge interface, a removable memory (e.g., a flash memory or other removable memory module) and memory slot, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to the computing system.

The computing system may also include a communication interface. The communication interface may be used to allow software and data to be transferred between the computing system and external devices. For example, the communication interfaces can include a modem, a network interface (such as an Ethernet or other network card), a communication port (such as a Universal Serial Bus (USB) port), a PCMCIA slot and card, and the like. 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 application, the terms "computer program product," "computer-readable medium," and the like are used generally to 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. These instructions, which are generally referred to as "computer program code" (which may be grouped in the form of computer programs or other groupings), when executed, enable the computer system to perform functions of embodiments of the present application. It is noted that the code may directly cause the processor to perform specified operations, may be compiled to do so, and/or may be combined with other software, hardware, and/or firmware elements (e.g., libraries for performing standard functions) to do so.

The non-computer readable medium may comprise at least one from the group of: hard disks, Compact disk Read Only memories (CD-ROMs), optical storage devices, magnetic storage devices, Read Only Memories (ROMs), Programmable Read Only Memories (PROMs), Erasable Programmable Read Only Memories (EPROMs), Electrically Erasable Programmable Read Only Memories (EEPROMs), and flash memories (flashmemories).

In embodiments implemented by software, the software may be stored in a computer-readable medium and loaded into the computing system using, for example, a removable storage drive. A control module (e.g., software instructions or executable computer program code) executed by a processor in a computer system causes the processor to perform functions as described herein.

Further, the present application may be applied in any circuit for performing signal processing functions in a network element. For example, it is further contemplated that a semiconductor manufacturer may employ the innovative concepts in the design of a stand-alone device, which may be a microcontroller (DSP) of a digital signal processor, an Application Specific Integrated Circuit (ASIC), and/or any other subsystem element.

For clarity of description, the foregoing description has described embodiments of the present application with reference to a single processing logic. However, the present application may equally well implement signal processing functions by means of a plurality of different functional units and processors. 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, physical structure or organization.

Aspects of the present application may be implemented in any suitable form including hardware, software, firmware or any combination of these. The present application may optionally be implemented, at least partly, as computer software, a computer software component, such as an FPGA device, running on one or more data processors and/or digital signal processors or configurable modules. 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 with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present application, and the scope of the present application is defined by the following claims. Furthermore, while descriptions of features related to particular embodiments may appear, one skilled in the art may, in light of the present disclosure, appreciate various features of such embodiments. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

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

Further, the ordering of features in the claims does not imply that the features must be performed in a particular order, and in particular the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. Furthermore, singular references do not exclude a plurality. Thus, the singular forms "a", "an", "first", "second", etc. do not exclude the plural forms.

Although the present application has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present application, and the scope of the present application is defined by the following claims. Furthermore, while descriptions of features related to particular embodiments may appear, one skilled in the art may, in light of the present disclosure, appreciate various features of such embodiments. In the claims, the term "comprising" or "including" does not exclude the presence of other elements.

Claims (17)

1. A method of paging a user equipment, UE, in a cellular wireless communication network, comprising:

transmitting a paging indication from the base station to indicate an available paging message;

transmitting a paging message, the paging message comprising a group indication and at least one UE indication, the group indication indicating at least one UE group to which the paging message applies, each UE indication indicating a paged UE to which the paging message applies, the at least one UE indication comprising an identity of the paged UE.

2. A method for paging a UE in accordance with claim 1, characterized in that said group indication of at least one group consists of a bitmap.

3. A method for paging a UE in accordance with claim 1 or 2, characterized in that the base station employs a beam scanning transmission method, and the paging message is transmitted on all beams of the beam scanning transmission method.

4. A method for paging a UE according to any one of claims 1 to 3, wherein the paging message further comprises at least one non-paged UE indication, each non-paged UE indication indicating non-paged UEs in at least one group of paged UEs for which the paging message is not applicable, the non-paged UE indication comprising an identity of the non-paged UE.

5. A method for paging a UE according to any of claims 1 to 4, characterized in that the identity of at least one paged UE and/or at least one non-paged UE is the S-TMSI or IMSI of the UE.

6. A method for paging a UE according to any of claims 1 to 5, further comprising: a paging format indicator is transmitted from a base station.

7. The method of paging a UE of claim 6, wherein the paging format indicator comprises an indication of a paging message that includes the group indication.

8. A method for paging a UE according to any of claims 6 or 7, characterized in that the paging format indicator is transmitted in a paging DCI or paging message.

9. The method of paging a UE of claim 8, wherein the paging message is a paging message associated with the paging format indicator.

10. The method of any one of claims 1 to 9, further comprising: an indication of the UE group to which a subsequent paging indication can be applicable is transmitted in the paging DCI.

11. A method for paging a UE in accordance with claim 1, wherein the paging message has a fixed format, wherein the group indication is located at a fixed location in the paging message, and wherein the at least one UE indication is located after the group indication.

12. A method for paging a UE in accordance with any one of claims 1 to 11, further comprising: and indicating a UE group to which at least one paging message is not applicable in the paging DCI transmitted by the base station.

13. The method for paging a UE according to any one of claims 1 to 12, further comprising:

allocating at least one general P-RNTI and at least one group common P-RNTI to at least one UE;

scrambling a paging indication message with the group common P-RNTI so that only UEs assigned to the group common P-RNTI can decode the paging indication.

14. A method for processing paging messages, the method being performed by a UE on the basis of messages received by a base station in a cellular radio communication network, the method comprising:

receiving a paging message;

determining whether the UE is in a paged UE group indicated by the message;

determining whether the UE is also identified as an unpanded UE in the group of UEs.

15. The method of claim 14, wherein the UE is further identified by an identifier of the UE.

16. The method of claim 15, wherein the identifier is an S-TMSI or IMSI of the UE.

17. The method according to any of claims 14 to 16, wherein if the UE is not in the indicated paged UE group and is not paged solely by its UE ID or if the UE is in the paged group and the UE is also indicated as not paged, the UE returns to sleep mode.

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