CN111373815A

CN111373815A - Method and apparatus for providing access control

Info

Publication number: CN111373815A
Application number: CN201780097020.7A
Authority: CN
Inventors: 李海涛; 张延冀; J-P·科斯基南
Original assignee: Nokia Solutions and Networks Oy; Alcatel Lucent SAS
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Alcatel Lucent SAS
Priority date: 2017-11-16
Filing date: 2017-11-16
Publication date: 2020-07-03
Also published as: WO2019095191A1

Abstract

A method includes applying, at a user equipment, an access policy for covering enhanced level access barring. The access policy depends on a state associated with the user equipment. Different policies may be applied depending on whether the device is moving or stationary.

Description

Method and apparatus for providing access control

Technical Field

Some embodiments relate to a method and apparatus for providing an access control mechanism.

Background

A communication system may be viewed as a facility that enables communication sessions between two or more entities, such as user terminals, base stations, and/or other nodes, by providing carriers between the various entities involved in a communication path. A communication system may be provided, for example, by means of a communication network and one or more compatible communication devices. A communication session may include, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text messages, multimedia and/or content data, etc. Non-limiting examples of services provided include two-way or multi-way calls, data communication or multimedia services, and access to data network systems, such as the internet.

In a wireless communication system, at least a portion of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems include Public Land Mobile Networks (PLMNs), satellite-based communication systems, and different wireless local area networks, such as Wireless Local Area Networks (WLANs). A wireless system may be generally divided into cells and is therefore generally referred to as a cellular system.

A user may access the communication system by means of a suitable communication device or terminal. The user's communication equipment may be referred to as User Equipment (UE) or user equipment. The communication device is provided with suitable signal receiving and transmitting means to enable communication, e.g. to enable access to a communication network or communication directly with other users. A communication device may access a carrier provided by a station (e.g., a base station of a cell) and transmit and/or receive communications on the carrier.

A communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters to be used for the connection are also typically defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology and the so-called 5G or new radio networks. Standardization of 5G or new radio networks is currently under discussion. LTE is being standardized by the third generation partnership project (3 GPP).

Disclosure of Invention

According to an aspect, there is provided a method comprising: applying, at a user equipment, an access policy for coverage enhancement level access barring, the access policy depending on a state associated with the user equipment.

The state may be a mobility state of the user equipment.

The status may include that the user equipment is one of: stationary user equipment and mobile user equipment.

The method can comprise the following steps: the method comprises receiving a first access policy for use when the user equipment is mobile and a second access policy for use when the user equipment is stationary, and applying either the first access policy or the second access policy depending on whether the user equipment is stationary or mobile.

The method can comprise the following steps: determining whether the user equipment is a stationary or mobile device, and applying a respective one of a first access policy and a second access policy in response to the determination.

The state may be a radio resource management monitoring state.

The state may be a radio resource management neighbor cell monitoring state.

The neighbor cell monitoring state may include one of: a neighbor cell monitoring state in which no monitoring is performed, a neighbor cell monitoring state in which neighbor cell measurements are performed on a first time scale, and a neighbor cell monitoring state in which neighbor cell measurements are performed on a second time scale, the second time scale being faster than the first time scale.

The neighbor cell monitoring state may include one of: a neighbor cell monitoring state, loose monitoring, and normal monitoring in which no monitoring is performed.

The method can comprise the following steps: receiving the access policy at the user equipment.

The method can comprise the following steps: a state is determined at the user equipment and an access policy is selected from a plurality of access policies depending on the determined state.

The applied policies may be associated with a given coverage enhancement level or levels.

The method can comprise the following steps: determining, at a user equipment, that a current coverage enhancement level for the user equipment is barred, and in response to the determination, attempting, by the user equipment, access using a different coverage enhancement level.

This may be performed, for example, by a stationary UE to avoid it being trapped/forbidden in an overloaded CE level.

This may be associated with no monitoring and/or relaxed monitoring and/or normal monitoring.

The method can comprise the following steps: receiving, at the user equipment, information indicating whether the user equipment is allowed to use a different coverage enhancement level when a current coverage enhancement level for the user equipment is barred.

The access policy may include information on which control procedure of the plurality of control procedures is to be performed.

This information may be provided for a plurality of different coverage enhancement levels.

Different information may be provided for a plurality of different coverage enhancement levels.

The information may include information indicating that coverage enhancement level barring is not performed for one or more coverage enhancement levels.

The information may include information indicating that coverage enhancement level barring is not performed for one or more coverage enhancement levels when the user equipment is stationary.

The information may include information indicating whether the first prohibited process is to be skipped, and the second prohibited process is performed in response to the information indicating that the first prohibited process is to be skipped.

This may be associated with a stationary user equipment and/or a mobile device depending on, for example, network policy. This may be associated with no monitoring and/or relaxed monitoring and/or normal monitoring.

The information may include information indicating that the second prohibition process is not required, and the first prohibition process is performed.

This may be associated with a stationary user equipment and/or a mobile user equipment depending on e.g. network policy. This may be associated with no monitoring and/or relaxed monitoring and/or normal monitoring.

The first barring procedure may comprise a cell level barring mechanism.

In some cases, this may be referred to as a "conventional" process. For example, in the context of 3GPP, this may be a previous release of Rel-15.

The second barring procedure may comprise coverage enhancement level barring.

The information may include at least one flag.

The applied policy may include barring threshold information for one or more coverage enhancement levels.

This may be associated with a stationary user device, for example, to allow the stationary user device to retry a different CE level when the current CE level is disabled.

According to another aspect, there is provided an apparatus in a user equipment, the apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: applying, at a user equipment, an access policy for coverage enhancement level access barring, the access policy depending on a state associated with the user equipment.

The state may be a mobility state of the user equipment.

The at least one memory and the computer program code may be configured to, with the at least one processor: the method comprises receiving a first access policy for use when the user equipment is mobile and a second access policy for use when the user equipment is stationary, and applying either the first access policy or the second access policy depending on whether the user equipment is stationary or mobile.

The at least one memory and the computer program code may be configured to, with the at least one processor: determining whether the user equipment is a stationary or mobile device, and applying a respective one of a first access policy and a second access policy in response to the determination.

The state may be a radio resource management monitoring state.

The state may be a radio resource management neighbor cell monitoring state.

The neighbor cell monitoring state may include one of: a neighbor cell monitoring state, a relaxation monitoring state, and a normal monitoring state in which monitoring is not performed.

The at least one memory and the computer program code may be configured to, with the at least one processor, receive the access policy at the user equipment.

The at least one memory and the computer program code may be configured to, with the at least one processor: a state is determined and an access policy is selected from a plurality of access policies depending on the determined state.

The at least one memory and the computer program code may be configured to, with the at least one processor: a current coverage enhancement level is determined to be barred, and access is attempted using a different coverage enhancement level in response to the determination.

The at least one memory and the computer program code may be configured to, with the at least one processor: receiving information indicating whether the user equipment is allowed to use a different coverage enhancement level when the current coverage enhancement level is barred.

The first barring procedure may comprise a cell level barring mechanism.

The second barring procedure may comprise coverage enhancement level barring.

The information may include at least one flag.

According to another aspect, there is provided an apparatus in an access node, the apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: transmitting an access policy to a user for coverage enhancement level access barring, the access policy dependent on a state associated with the user equipment.

The state may be a mobility state of the user equipment.

The at least one memory and the computer program code may be configured to, with the at least one processor: causing transmission of a first access policy for use when the user equipment is mobile and a second access policy for use when the user equipment is stationary, and applying either the first access policy or the second access policy depending on whether the user equipment is stationary or mobile.

The at least one memory and the computer program code may be configured to, with the at least one processor: determining whether the user equipment is a stationary or mobile device, and providing a respective one of a first access policy and a second access policy in response to the determination.

The state may be a radio resource management monitoring state.

The state may be a radio resource management neighbor cell monitoring state.

The at least one memory and the computer program code may be configured to, with the at least one processor: causing transmission of information to the user equipment indicating whether the user equipment is allowed to use a different coverage enhancement level when a current coverage enhancement level for the user equipment is barred.

This may be associated with a stationary user equipment and/or a mobile device depending on, for example, network policy.

This may be associated with a stationary user equipment and/or a mobile user equipment depending on e.g. network policy.

The first barring procedure may comprise a cell level barring mechanism.

The second barring procedure may comprise coverage enhancement level barring.

The information may include at least one flag.

According to another aspect, there is provided a method comprising: transmitting an access policy to a user for coverage enhancement level access barring, the access policy dependent on a state associated with the user equipment.

The state may be a mobility state of the user equipment.

The method can comprise the following steps: causing transmission of a first access policy for use when the user equipment is mobile and a second access policy for use when the user equipment is stationary, and applying either the first access policy or the second access policy depending on whether the user equipment is stationary or mobile.

The method can comprise the following steps: determining whether the user equipment is a stationary or mobile device, and providing a respective one of a first access policy and a second access policy in response to the determination.

The state may be a radio resource management monitoring state.

The state may be a radio resource management neighbor cell monitoring state.

The method can comprise the following steps: causing transmission of information to the user equipment indicating whether the user equipment is allowed to use a different coverage enhancement level when its current coverage enhancement level is barred.

The first barring procedure may comprise a cell level barring mechanism.

The second barring procedure may comprise coverage enhancement level barring.

The information may include at least one flag.

A computer program may also be provided comprising program code means adapted to perform the method(s). The computer program may be stored and/or otherwise embodied by means of a carrier medium. The computer program may be provided on a non-transitory computer program carrying medium.

Many different embodiments have been described above. It is to be understood that further embodiments may be provided by a combination of any two or more of the above embodiments.

Various other aspects and additional embodiments are also described in the following detailed description and the appended claims.

Drawings

Some embodiments will now be described, by way of example only, and with reference to the following drawings, in which:

fig. 1 shows a schematic diagram of an example communication system comprising a base station and a plurality of communication devices;

FIG. 2 shows a schematic diagram of an example mobile communication device;

FIG. 3 shows a schematic diagram of an example control apparatus; and

fig. 4 shows a method flow.

Detailed Description

Before explaining the examples in detail, certain general principles of wireless communication systems and mobile communication devices are briefly explained with reference to fig. 1 to 3 to help understand the underlying technology of the described examples.

In a wireless communication system 100 such as that shown in fig. 1, wireless communication devices (e.g., User Equipment (UE)102, 104, 105) are provided wireless access via at least one base station or similar wireless transmitting and/or receiving wireless infrastructure node or point. Such a node may be, for example, a base station or enodeb (enb), or in a 5G system, a next generation nodeb (gnb), or other wireless infrastructure node. These nodes will generally be referred to as base stations. The base stations are typically controlled by at least one suitable controller means to effect their operation and management of the mobile communications devices communicating with the base stations. The controller device may be located in a radio access network (e.g., the wireless communication system 100) or in a Core Network (CN) (not shown) and may be implemented as one central device, or its functionality may be distributed over several devices. The controller means may be part of the base station and/or provided by a separate entity such as a radio network controller. In fig. 1, the control means 108 and 109 are shown as controlling the respective

macro base stations

106 and 107. In some systems, the control means may additionally or alternatively be provided in the radio network controller. Other examples of radio access systems include those provided by base stations of systems based on technologies such as 5G or new radio, Wireless Local Area Network (WLAN) and/or WiMax (worldwide interoperability for microwave access). A base station may provide coverage for an entire cell or similar radio service area.

In fig. 1,

base stations

106 and 107 are shown connected to a wider communications network 113 via a gateway 112. Further gateway functionality may be provided to connect to another network.

Smaller base stations

116, 118 and 120 may also be connected to the network 113, for example, by separate gateway functions and/or via controllers of macro-level stations.

Base stations

116, 118, and 120 may be pico or femto base stations, and the like. In this example,

stations

116 and 118 are connected via gateway 111, while station 120 is connected via controller device 108. In some embodiments, smaller stations may not be provided.

A possible wireless communication device will now be described in more detail with reference to fig. 2, which fig. 2 shows a schematic partial cut-away view of a communication device 200. Such communication devices are commonly referred to as User Equipment (UE) or terminals. Suitable mobile communication devices may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a Mobile Station (MS) or mobile device, such as a mobile phone or so-called "smart phone", a computer provided with a wireless interface card or other wireless interface facility (e.g., a USB dongle), a Personal Data Assistant (PDA) or tablet provided with wireless communication capabilities, or any combination of these devices, etc. Mobile communication devices may provide for communication of data, e.g., for carrying communications such as voice, electronic mail (email), text messages, multimedia, etc. Thus, many services may be offered and provided to a user via the user's communication device. Non-limiting examples of such services include two-way or multi-way calling, data communication or multimedia services, or simply access to a data communication network system, such as the internet. Broadcast or multicast data may also be provided to the user. Non-limiting examples of content include downloads, television and radio programs, videos, advertisements, various alerts, and other information.

The wireless communication device may be, for example, a mobile device, i.e. a device that is not fixed to a specific location, or it may be a stationary device.

Wireless devices may or may not require human interaction to communicate. The latter devices are sometimes referred to as MTC (machine type communication) devices. Such a device may have only a subset of the components shown in fig. 2 and/or a simplified version of the components. In the present teachings, the term "UE" is used to refer to any type of wireless communication device.

A mixture of different types of devices may be configured to operate within a network.

The wireless device 200 may receive signals over the air or radio interface 207 via appropriate means for receiving and may transmit signals via appropriate means for transmitting radio signals. In fig. 2, a transceiver device is schematically represented by block 206. The transceiver device 206 may be provided, for example, by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged inside or outside the wireless device.

The wireless device is typically provided with at least one data processing entity 201, at least one memory 202 and possibly other components 203 for performing tasks it is designed to perform, including controlling access to and communication with access systems and other communication devices, with the aid of software and hardware. The data processing, storage and other related control means may be provided on a suitable circuit board and/or in a chipset. This feature is denoted by reference numeral 204.

Alternatively, the user may control the operation of the wireless device by means of a suitable user interface, such as a keypad 205, voice commands, a touch sensitive screen or touch pad, combinations thereof or the like. A display 208, a speaker, and a microphone may optionally be provided.

Further, the wireless communication device may optionally include appropriate connectors (wired or wireless) to other devices and/or for connecting external accessories (e.g., hands-free devices) thereto. The

communication devices

102, 104, 105 may access the communication system based on various access technologies.

Fig. 3 shows an example of an apparatus that may be provided in a base station. The apparatus 300 comprises at least one memory 301, at least one

data processing unit

302, 303 and an input/output interface 304. Via the interface, the control device may be coupled to a receiver and a transmitter of the base station. The receiver and/or transmitter may be implemented as a radio front end or a remote radio head. For example, the control device 300 or the processor 201 may be configured to execute suitable software code to provide the control functionality.

The narrowband LTE system may support Machine Type Communication (MTC) or machine-to-machine communication (M2M). This narrowband LTE system may sometimes be referred to as LTE-M.

The internet of things (IoT) is known. The IoT includes interworking of interconnected devices (including but not limited to user devices, vehicles, home appliances, etc.). Narrowband IoT (NB-IoT) is a radio technology standard that is used to enable IoT devices to communicate using a cellular network. Improvements to NB-IoT are ongoing.

The goal of NB-IoT enhancements and LTE-M is to enhance access barring. This may be used to improve access and/or load control in idle mode, e.g. access barring based on CE (coverage enhancement) level.

Coverage enhancement CEs have been proposed. CEs have been proposed to address issues such as the need to extend the range and/or coverage associated with a base station. CE may be implemented by, for example, increasing the number of repetitions of the transmission. CE may have a number of different levels. The number of different levels may be any suitable number. For example, current proposals have up to 4 levels for LTE-M and up to 3 levels for NB-IoT. Different offers may have different levels. Each level may be associated with a different number of transmission repetitions.

In some embodiments, access by a UE to a particular cell may be prohibited or limited depending on the CE level and/or mode.

A UE with a higher CE level may require more resources than a UE with a lower CE level. In some embodiments, the probability of the UE obtaining resources may be the same regardless of the CE level. In other embodiments, the probability of the UE obtaining resources may depend on the CE level.

Currently, with the LTE specifications, the NB-IoT access control feature is referred to separately from the LTE access control mechanism as access barring AB. The access barring may be intended for delay tolerant services, e.g., Machine Type Communication (MTC) services without strict delay requirements. The barring bitmap may be transmitted in a system information block. It has been proposed to transmit this information in a narrowband system information block SIB. This information may be sent separately from other system information. So-called SIB14 or SIB2 has been proposed to transmit this bitmap information. The bitmap information may be transmitted only when access control is enabled.

Currently, neither NB-IoT nor LTE-M support load balancing between different CE levels when accessing a cell.

Potentially, the base station may restrict access to certain CE level users to avoid overloading. Different CE levels may be associated with different radio resources. For example, PRACH (physical random access channel) resources may be separated for different CE levels. This may be CE level(s) or pattern associated with a relatively high repetition rate. Fairness issues may arise for UEs whose coverage is always poor, e.g. UEs in the form of stationary underground meters. If the UEs are not differentiated when accessing the NW, these stationary UEs may not have as good chance to establish a connection as other UEs that happen to move to the cell edge. The meter report may then be delayed or lost.

Consider the following: for an always stationary meter, the access probability set for the CE level is small. These meters may be disabled most of the time when attempting to send data to the network, but the mobile UE may have a chance to move to other CE levels with a higher probability of access and thus have a higher chance of gaining access.

In one case, the stationary UE may stay at the most robust repetition level (i.e., the most number of repetitions). The CE level may be level 3. This may be due to congestion at this level at high loads. For example, a portion of the mobile UEs also depend on the same level. This may result in multiple stationary UEs staying at the CE level because the UEs are in a stationary, unchanging radio environment, while a mobile UE may expect a dynamic radio environment to bring the UE off the CE level.

In some embodiments, different access probabilities for stationary and mobile UEs may be provided so that a portion of the mobile UEs may move out of the CE level in question. This may be achieved by disabling a proportion of these mobile UEs from the CE level. This may result in reduced congestion from stationary UEs in the CE level. These probabilities may be in units of per-CE levels, or may be specifically applied to CE levels. The base station may provide different access probabilities to the UE. As another alternative, the base station may provide a common probability for each CE level or a particular CE level and provide the stationary UEs with an additional scaling factor from which the access probabilities for the stationary UEs may be derived. The UE itself can determine whether it is stationary or mobile and then apply the appropriate access probability. Alternatively or additionally, this may be determined by the base station and signaled to the UE.

Access barring may address congestion on the PRACH. For eMTC (enhanced MTC) and NB-IoT, different resources are used for PRACH per CE level. This may provide finer granularity for the network to perform congestion control at each CE level.

For a given access barring, there may be an associated access probability (sometimes referred to as a barring factor) and access class barring time. When the UE requests access, it derives a random number between 0 and 1 and compares this number with the access probability. When the number is less than the access probability, the device proceeds to a random access procedure. Otherwise, the device will be barred for a period of time before attempting to access the network again.

Some embodiments may relate to an access barring mechanism for one or more of: NB-IoT, LTE-M, and NR UE. Of course, other embodiments may involve any other suitable criteria.

Some embodiments may distinguish stationary UEs from mobile UEs and apply different access policies for stationary UEs and mobile UEs. Any suitable parameter may be used to distinguish between UEs. This may be based on, for example, RSRP (reference signal received power) variation or cell reselection count/result of the serving cell. In some embodiments, different access policies for stationary and mobile UEs may be applied.

Some embodiments may provide one or more options to enhance access barring mechanisms for different CE levels.

In some embodiments, different barring factors/probabilities for different CE levels are signaled to the UE. This may allow the network to set different access probabilities based on an estimate of the number/distribution of UEs and/or access activity in each CE level.

In some embodiments, an indication is provided as to whether the UE is allowed to attempt to access the cell at another CE level when the current CE level is barred. This is because the traffic load of different CE levels may be independent, and an overload of one CE level does not necessarily mean that the other CE levels are also overloaded. This may allow the UE to access the network via a less loaded CE level when the cell is barred in the current overloaded CE level.

In some embodiments, a skip indication is provided to allow the UE to skip existing barring mechanisms and directly perform CE level based access barring. If for some reason the network has to set the existing barring factor to be relatively high, the UE will most likely not be able to pass access control even if the CE level specific barring factor is not that high for certain CE levels. In this case, skipping the existing barring mechanism may help the UE to apply radio resources more efficiently through access control.

The UE may be signaled which access barring mechanism the UE should follow. The base station may define the access barring mechanism according to the policies the base station follows.

The UE may be signaled: for a certain CE level, disabling based on the CE level is allowed to be ignored. For example, for a stationary UE at an overloaded CE level, ignoring CE-level-based barring may avoid the UE being barred in that CE level if the network wants the UE to access.

The UE may determine that the UE is allowed to ignore the CE level-based barring. For example, as described above, a stationary UE may benefit from it, which would otherwise always be barred by an overloaded CE level.

The disabling function may be based on RRM (radio resource management monitoring).

It should be understood that some embodiments may use a single one of the above options or a combination of two or more of the options.

The signaling from the access point or base station may be via broadcast communication and/or via dedicated signaling.

Referring to fig. 4, fig. 4 illustrates a method of an embodiment.

In step S1, the base station will broadcast or signal the barring factor for different CE levels. This may be for all UEs in the cell, for all LTE-M UEs in the cell, for all NB-IoT UEs in the cell, or for a particular UE. This is in contrast to existing arrangements in which one access control probability is provided for the UE. This barring factor is used for access control and is different from the weighting factor for anchor/non-anchor PRBs (physical resource blocks) of the PRACH. These weighting factors may be broadcast to the UE and may be used by the UE to select the PRBs on which it transmits the random access preamble.

In step S2, it is determined whether the UE passes a given level of access control.

If so, the next step is step S3, in step S3, only after the UE has passed access control for a given CE level, can the UE select PRBs to perform RA (random access procedure) on that CE level based on the weighting factors of the anchor/non-anchor PRBs. The given CE level may be selected by the UE depending on one or more factors. For example, the CE level may be selected based on a measured RSRP reference signal received power and/or RSRQ reference signal received quality, and/or the like. In other embodiments, the CE level may alternatively or additionally be selected depending on the amount of data that the UE has to transmit. In other embodiments, the base station may determine the CE level based on one or more factors. If the base station selects the selected CE level, the selected CE level may be signaled to the UE.

In some embodiments, the base station may signal to the UE whether the UE is allowed to attempt to access the cell at another CE level. For example, if the cell is barred in the current CE level (e.g., the CE level associated with the measured RSRP result), the base station may indicate that the UE is allowed to attempt a different, deeper (higher repetition rate) CE level. The allow/disallow indication may be signaled per cell or per CE level. This may be beneficial because the traffic load of different CE levels may be independent, and an overload of one CE level does not necessarily mean that the other CE levels are also overloaded. It should be understood that this information may be transmitted together with the information in step S1, or may be transmitted separately. In some embodiments, the information of step S1 may be broadcast and this additional information as to whether the UE is allowed to access the cell at another CE level may be signaled to the UE.

In the embodiment where additional information is provided, when it is determined that the UE does not pass the access control of the given level, the next step is step S4, and in step S4, it is determined whether the UE is allowed to try another level.

If so, the next step is S5, and in step S5, it is determined whether the UE passes the access control of the new CE level.

If so, the next step is S3, and if not, the next step is step S4.

It should be understood that in the case where the UE is allowed to attempt another level, the UE may need to first perform n attempts to access the given level before it is allowed to attempt to access the next CE level. N is an integer greater than or equal to 1.

In some embodiments, alternatively or additionally, the permission/non-permission to attempt another CE level may be determined based on a barring factor threshold configured by the base station. For example, only those CE levels that have a sufficiently low barring factor (e.g., below the barring factor threshold) are allowed to retry for access at another CE level. The threshold may be signaled by the base station. For example, the threshold may be broadcast by the base station along with a barring factor for each CE level. For example, the CE level may be allowed to retry access when the barring factor is below, for example, 0.3.

In some embodiments, the base station may configure the UE configuration to skip existing legacy barring mechanisms and directly perform CE level based access barring checks such as discussed with respect to fig. 4. The conventional barring mechanism is a cell level barring mechanism. Whenever the UE wants to access the cell, the UE draws a random number and checks to see if it is smaller than the cell level barring factor. If so, the UE is allowed to perform the RA procedure; if not, the cell is barred.

In some embodiments, CE level access barring may be disabled based on an indication from a base station for a particular CE level (e.g., when the barring factor is too high and thus blocks access). The indication may be a flag or an indication for CE level. The purpose of the indication may be to disable access barring for that CE level. This means that the UE does not need to perform barring control for this CE level as long as the UE passes the legacy (cell level) barring control.

In some embodiments, the UE may skip legacy (cell-level) barring control and directly perform CE-level barring control. This may be indicated by the base station.

The base station may indicate whether to allow ignoring CE level based access control for a certain CE level. This may be provided in system information broadcasting or the like. When CE level-based access control may be ignored and/or what may occur when CE level-based access control is ignored may be determined by the UE according to one or more criteria defined by the base station.

The UE may determine from its assessment of the stationary state whether it can ignore CE level based access control, e.g., by detecting a change in its serving cell RSRP or cell reselection count.

Once access control based on the CE level has been ignored, the UE may perform a normal AC check during initial access. The goal may be to avoid fairness issues for those stationary UEs that always require deeper CE levels. This means that as long as the UE passes the normal AC check, it is allowed to access the cell using the CE level without further performing CE level-based access control for the CE level.

For a subsequent transition from the idle state to the connected state, the UE may ignore the CE level based AC and perform normal AC procedures if the UE satisfies one or more of the following conditions:

the UE attempts to establish a connection using the same cell as the last serving cell in the connected state;

the UE operates at a certain CE level indicated by the base station during the connected state

Upon initiating a state transition, the UE remains at the same CE level

In some embodiments, the different barring behaviors may be based on UE RRM monitoring, i.e. the UE applies barring based on the UE RRM neighbor cell monitoring state, e.g. as follows:

1) without monitoring

In this case, the UE may select legacy barring. Alternatively or additionally, the inhibition check is performed only for certain CE level(s)

2) Relaxation monitoring

For example, the UE may select CE level barring. Alternatively or additionally, the inhibition check is performed only for certain CE level(s).

3) Normal monitoring

For example, the UE may select two barring mechanisms. The UE may sequentially perform AC: first, it is the legacy cell level AC, and if it passes, it is the CE level AC, and if it passes, the UE is allowed to perform the RA procedure for that CE level. Alternatively or additionally, the inhibition check is only performed for certain CE level(s).

In some embodiments, only one of the monitoring states is provided. It should be understood that in some embodiments, two or more of these monitoring states may be provided.

The UE may dynamically determine whether to apply relaxation monitoring through a change in serving cell RSRP, or the like. If there are configuration parameters for dynamically determining whether to apply relaxation monitoring, these configuration parameters may be provided by means of system information. Relaxation monitoring may be applicable when the UE is below a neighbor cell measurement threshold (such as Sintrasearch or Sintersearch threshold), respectively, if already configured.

A UE applying "relaxed monitoring" may need to perform neighbor cell measurements on a relatively slow time scale, regardless of whether the UE considers itself stationary or not.

The slow time scale may be the same or different for different UEs.

The UE may apply the neighbor cell measurement "normal mobility requirement" or "relaxed monitoring requirement".

Some embodiments may provide one or more of the following advantages.

Some embodiments may achieve load balancing between different CE levels.

Some embodiments may allow offloading from a congested CE level to another CE level. This may reduce latency and/or improve resource utilization efficiency.

Some embodiments may address fairness issues for stationary UEs that are always in poor coverage locations.

In LTE, the ACB mechanism includes a set of access classes. For example, categories 0 to 9 are for regular users, category 10 is for emergency calls, and categories 11 to 15 are for high priority or operator services.

It should be understood that embodiments may be used with any suitable standard. Some embodiments may be used with narrowband arrangements such as NB-LTE, LTE-M, and NB-IoT. However, these are merely examples, and some embodiments may be used in any other suitable scenario. Some embodiments may be used with non-narrowband scenes.

It is to be understood that these means may comprise or be coupled to other units or modules or the like, such as a radio part or radio head for transmission and/or reception. Although an apparatus has been described as one entity, different modules and memories may be implemented in one or more physical or logical entities.

Although certain embodiments are described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable form of communication system in addition to the communication systems shown and described herein.

It should also be noted herein that while the above describes exemplifying embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

Embodiments of the invention may be implemented by computer software executable by a data processor of a mobile device, such as in a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets and/or macros can be stored in any device-readable data storage medium and they include program instructions for performing particular tasks. The computer program product may comprise one or more computer-executable components configured to perform embodiments when the program is run. The one or more computer-executable components may be at least one software code or a portion thereof.

Further in this regard it should be noted that any block of the logic flow as in the figures may represent a program step, or an interconnected set of logic circuits, blocks and functions, or a combination of a program step and a logic circuit, block and function. The software may be stored on physical media such as memory chips or memory blocks implemented within the processor, magnetic media such as hard or floppy disks, and optical media such as, for example, DVDs and data variants thereof, CDs. The physical medium is a non-transitory medium.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processor may be of any type suitable to the local technical environment, and may include, by way of non-limiting example, one or more of the following: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), FPGAs, gate level circuits, and processors based on a multi-core processor architecture.

Embodiments of the invention may be practiced in various components such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiments of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention, as defined in the appended claims. Indeed, there are additional embodiments that include a combination of one or more embodiments with any other embodiments previously discussed.

Claims

1. A method, comprising:

applying, at a user equipment, an access policy for coverage enhancement level access barring, the access policy depending on a state associated with the user equipment.

2. The method of claim 1, wherein the state is a mobility state of the user equipment.

3. The method of claim 1 or 2, wherein the status comprises the user equipment being one of: stationary user equipment and mobile user equipment.

4. A method according to claim 2 or 3, comprising: receiving a first access policy for use when the user equipment is mobile and a second access policy for use when the user equipment is stationary, and applying either the first access policy or the second access policy depending on whether the user equipment is stationary or mobile.

5. The method of claim 2, 3 or 4, comprising: determining whether the user equipment is a stationary or mobile device, and applying a respective one of the first and second access policies in response to the determination.

6. The method of any preceding claim, wherein the state is a radio resource management neighbour cell monitoring state.

7. The method of claim 6, wherein the neighbor cell monitoring state comprises one of: a neighbor cell monitoring state in which no monitoring is performed, a neighbor cell monitoring state in which neighbor cell measurements are performed on a first time scale, and a neighbor cell measurement state in which neighbor cell measurements are performed on a second time scale, the second time scale being faster than the first time scale.

8. The method of any preceding claim, comprising: determining a state at the user equipment, and selecting an access policy from a plurality of access policies depending on the determined state.

9. The method of claim 8, wherein the policy applied is associated with a given one or more coverage enhancement levels.

10. The method of any preceding claim, comprising: determining, at the user equipment, that a current coverage enhancement level for the user equipment is barred, and in response to the determination, attempting, by the user equipment, access using a different coverage enhancement level.

11. The method of any preceding claim, comprising: receiving, at the user equipment, information indicating whether the user equipment is allowed to use a different coverage enhancement level when the current coverage enhancement level for the user equipment is barred.

12. A method according to any preceding claim, wherein the access policy comprises information regarding which of a plurality of control procedures is to be performed.

13. The method of claim 12, wherein the information comprises information indicating that coverage enhancement levels are prohibited from being performed for one or more coverage enhancement levels when the user equipment is stationary.

14. The method of claim 12 or 13, wherein the information comprises information indicating whether a first prohibited process is to be skipped, and performing a second prohibited process in response to the information indicating that the first prohibited process is to be skipped.

15. A method according to any preceding claim, wherein the policy applied comprises barring threshold information for one or more coverage enhancement levels.

16. A method, comprising: transmitting an access policy to a user for coverage enhancement level access barring, the access policy dependent on a state associated with the user equipment.

17. A computer program comprising computer executable code which when run on at least one processor causes the method of any preceding claim to be performed.

18. An apparatus in an access node, comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

transmitting an access policy to a user for coverage enhancement level access barring, the access policy dependent on a state associated with the user equipment.

19. An apparatus in an access node, comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: