(19)
(11)EP 2 577 933 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
12.07.2017 Bulletin 2017/28

(21)Application number: 11724784.1

(22)Date of filing:  02.05.2011
(51)Int. Cl.: 
H04L 29/06  (2006.01)
H04W 12/08  (2009.01)
H04L 29/08  (2006.01)
H04W 4/00  (2009.01)
(86)International application number:
PCT/IB2011/051940
(87)International publication number:
WO 2011/151747 (08.12.2011 Gazette  2011/49)

(54)

LAYERED ACCESS CONTROL FOR MACHINE TYPE COMMUNICATION DEVICES

MEHRSCHICHTIGE ZUGANGSKONTROLLE FÜR MACHINENTYP KOMMUNIKATIONSVORRICHTUNGEN

GESTION D'ACCÈS EN COUCHES POUR DES APPAREILS DE COMMUNICATION DE TYPE MACHINAL


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 18.03.2011 US 201113051361
10.06.2010 US 353308 P
04.06.2010 US 351468 P

(43)Date of publication of application:
10.04.2013 Bulletin 2013/15

(73)Proprietor: Telefonaktiebolaget LM Ericsson (publ)
164 83 Stockholm (SE)

(72)Inventors:
  • DIACHINA, John
    Garner North Carolina 27529 (US)
  • SCHLIWA-BERTLING, Paul
    S-590 71 Ljungsbro (SE)
  • BERGSTRÖM, Andreas
    S-590 47 Vikingstad (SE)

(74)Representative: Ericsson 
Patent Development Torshamnsgatan 21-23
164 80 Stockholm
164 80 Stockholm (SE)


(56)References cited: : 
WO-A1-99/44379
WO-A2-2006/093557
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    RELATED APPLICATIONS



    [0001] This application claims the benefit of U.S. Provisional Patent Applications Serial No. 61/351,468 filed on June 4, 2010 and Serial No. 61/353,308 filed June 10, 2010.

    BACKGROUND



    [0002] The present invention relates generally to access control in mobile communication networks and, more particularly, to access control for wireless terminals or machine-type communication (MTC) devices.

    [0003] The random access channel (RACH) in mobile communication networks provides contention-based access to wireless terminals to request connection setup when no traffic channel has been allocated to the wireless terminal. In systems based on the GSM/EDGE standard, the wireless terminal sends an access request message to the network on the RACH. The access request message includes a randomly generated reference value - such as the Reference Request information - for identification purposes, in lieu of an identifier such as the IMSI, for reasons of security and minimizing the amount of information sent by a wireless terminal to accomplish contention resolution. The wireless terminal then monitors the Access Grant Channel (AGCH) for a response. The network may either accept or deny the access request. If it accepts it, the network transmits an Immediate Assignment (IA) message on the AGCH, identifying the wireless terminal by the random reference value included in the access request message and directing it to a traffic channel. If the network denies access to the requesting wireless terminal, it transmits an Immediate Assignment Reject (IAR) message.

    [0004] Contention occurs on the RACH occur when two or more wireless terminals attempt to access the communication network at the same time. In the event of a contention, the network will resolve the contention in favor of one of the wireless terminals. The unsuccessful wireless terminals will then "back-off' and make a new access attempt at a later time. As the number wireless terminals increases, there is a greater probability of contention between the wireless terminals and a greater number of access attempts will fail. If too many contentions occur, throughput on the RACH will be significantly reduced.

    [0005] The anticipated introduction of a large volume of machine-type communication (MTC) devices in the near future will greatly increase the problem of congestion on the RACH. MTC devices are devices, such as a meter or sensor, that collect and send data to an MTC server or other MTC device over a communication network. It is expected that MTC devices will far outnumber non-MTC devices, such as user terminals for voice and data communications by human users. Therefore, there is a need to implement new procedures to control network access by MTC devices and minimize the impact on non-MTC devices.

    SUMMARY



    [0006] Embodiments of the present invention provide methods and apparatus for controlling network access on a contention-based RACH by MTC devices. More particularly, a layered approach to access control is used where each access control layer implements a set of access control rules based on different attributes. The access control rules in each layer are applied in order beginning with the first access control layer. That is, the access control rules for access control layer 1 are applied first, followed by the access control rules for access control layer 2, and so forth. To gain access to the network 100, the access attempt must not be barred by any access control layer.

    [0007] Exemplary embodiments of the invention comprise methods of access control implemented by a base station. In one exemplary embodiment, the method comprises selectively enabling one or more ordered access control layers based on an application type for each one of a plurality of application types, where each access control layer comprises a set of access control rules; and signaling the enabled access control layers for each application type to access terminals associated with said applications.

    [0008] Other embodiments comprise a base station implementing a layered access control scheme. In one embodiment, the base station comprises a transceiver for communicating with one or more access terminals and a control unit connected to the transceiver for controlling access to the communication network by an application. The control unit includes a processor configured to selectively enable one or more ordered access control layers based on an application type for each one of a plurality of application types, where each access control layer comprising a set of access control rules; and transmit information specific to the enabled access control layers for each application type to access terminals hosting applications accessing the communication network.

    [0009] Other embodiments comprise an access control method implemented by an MTC device. In one exemplary embodiment, the method comprises determining an application type for an application that is attempting to access said communication network; determining which of two or more ordered access control layers are enabled for the application type, wherein each access control layer comprises one or more sets of access control rules; and applying, in order by layer, the access control rules for the enabled access control layers to control access to the network by the application.

    [0010] Other embodiments comprise an MTC device implementing a layered access control scheme. In one embodiment, the MTC device comprises a transceiver for communicating with a base station in a communication network and a control unit connected to the transceiver for controlling access to the a communication network by an application attempting to access the communication network. The control unit includes a processor configured to determine an application type for the application; determine which of two or more layers are enabled for the application type, wherein each access control layer comprises one or more sets of access control rules; and apply, in order by layer, the access control rules for the enabled access control layers to control access to the network by the application.

    [0011] With the multi-layered access control scheme, network operators are provided with the ability to bar system access by MTC applications with fine granularity. The layered access control scheme also provides the network operator with the ability to determine what types of network accesses are barred at any point in time and the period for which the barring is to be applied. Barring may be applied separately to user plane and control plane applications. The following is a more detailed description of one exemplary access control scheme.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0012] 

    Fig. 1 illustrates an exemplary communication network for communication by MTC devices.

    Fig. 2 illustrates a layered access control scheme for MTC devices.

    Fig. 3 illustrates an exemplary method of access control implemented by an MTC device.

    Fig. 4 illustrates an exemplary access control procedure implemented by a base station.

    Fig. 5 illustrates an MTC device implementing a layered access control scheme.

    Fig. 6 illustrates an exemplary base station implementing a layered access control scheme.


    DETAILED DESCRIPTION



    [0013] Referring now to the drawings, Fig. 1 illustrates an exemplary wireless communication network 10. The communication network 10 may, for example, comprise a mobile communication network 12 that operates according to any standard that employs a contention-based random access channel (RACH). For illustrative purposes, an exemplary embodiment of the present invention will be described in the context of a network operating according to the GSM/EDGE standard. Those skilled in the art will appreciate, however, that the present invention is more generally applicable to other wireless communication systems, including Wideband Code Division Multiple Access (WCDMA), Long-Term Evolution (LTE), and Worldwide Interoperability for Microwave Access (WiMAX) systems. The mobile communication network 10 comprises a core network 12 that connects to an external packet data network 14, such as the Internet, and a plurality of base stations 20 that provide network access to wireless terminals 100. The wireless terminals 100 may communicate with one or more servers 30 connected to the mobile communication network 10 or packet data network 14.

    [0014] The wireless terminals 100 may comprise machine-type communication (MTC) devices for collecting and reporting of data over a communication network or non-MTC devices. Machine Type Communications (MTC) has been defined as a specific type of wireless communication network traffic. See, e.g., 3GPP Technical Report 23.888, "System Improvements for Machine-Type Communications," the disclosure of which is incorporated herein by reference in its entirety. One example of an MTC device is a gas or power meter with a wireless transceiver for reporting at predetermined time periods usage of gas or electrical power to an MTC server 30. Non-MTC devices are devices, such as a cell phone, smart phone, laptop computer, etc., used for voice and data communications by human users. An MTC device may comprise a dedicated device specifically for data collection and reporting. In other embodiments, a combined wireless terminal 100 may function part of the time as a MTC device and part of the time as a non-MTC device. The MTC devices collect data and send the collected data to an MTC server 30, which may connect directly to the mobile communication network 12 or to the PDN 14.

    [0015] In order to send the data, a wireless terminal 100 must first establish a connection with the communication network 10. Typically, the wireless terminal 100 registers with the communication network 10 on power up. After registering with the network 10, the wireless terminal 100 may enter an IDLE mode. In the IDLE mode, the wireless terminal 100 does not have an established connection with a base station 20. When the wireless terminal 100 has data to send, it uses a random access procedure to establish a connection with the base station 20 to transmit the data. After the data is transmitted, the wireless terminal 100 may terminate the connection with the base station 20 and return to an IDLE mode. In most typical applications, the wireless terminal 100 will remain attached with the network 10. However, the wireless terminal 100 could detach from the network 10 after sending the data.

    [0016] Currently, both MTC devices and non-MTC devices all use the same RACH resources. Thus, MTC devices and non-MTC devices must contend with one another for access on the RACH. Due to the rapid growth of MTC devices, it is expected that the number of MTC devices will far exceed the number of non-MTC devices in the near future. To avoid overload and congestion of the RACH, the service providers will require a greater degree of control over network access by MTC devices.

    [0017] MTC devices are likely to be configured (e.g., pre-programmed) with a profile identifying service-related attributes that correspond to each particular type of device and/or the applications supported by the device. Some of these attributes will be selected from a set of ubiquitous service-related attributes that identify broad types of devices and/or applications. For instance, these attributes might indicate that an application or device is delay tolerant, has low mobility, or has only small data transmission requirements. Given that MTC devices will have a specific profile of MTC service attributes, the radio access network (RAN) can apply an access control mechanism indicating that system accesses are barred for MTC devices having one or more of these service attributes enabled.

    [0018] Applying an access control mechanism may be necessary during periods of heavy access load, so as to throttle the number of MTC devices that actually attempt system access during this time period. In other words, this access control mechanism effectively provides operators with the ability to bar system access attempts from MTC devices possessing different service attribute profiles. The ability to distinguish between devices having different service attributes permits the operator to regulate access attempts with an operator-determined granularity (i.e., from 0% to 100%), and for operator-determined time intervals.

    [0019] According to one embodiment of the present invention, a layered access control scheme is used to provide a high degree of control over network access attempts by MTC devices. Fig. 2 illustrates schematically a layered access control scheme according to one embodiment of the present invention. The access control rules are contained in distinct access control layers. Each access control layer comprises one or more sets of access control rules, which may apply to different types of MTC applications. When an MTC device attempts to access the network, the access control rules are applied in order by layer. That is, the access control rules for access control layer 1 are applied first, followed by the access control rules for access control layer 2, and so forth. To gain access to the network 100, the MTC device must not be barred by any access control layer. In other words, the access control rules in any one layer may bar access. As will be hereinafter described in greater detail, the access control layers can be selectively enabled and disabled to provide a high degree of control over network access by MTC devices. When an access control layer is enabled, the corresponding access control rules are applied. Conversely, when the access control layer is disabled, the access control rules corresponding to that layer are disregarded. The layered access control scheme may be applied to access attempts by both user plane applications and control plane applications on MTC devices.

    [0020] Table 1 below illustrates an exemplary access control approach according to one embodiment of the invention using four access control layers.
    Table 1: Attributes for Layered Access Control Approach
    Access Control LayerUser Plane ApplicationsControl Plane Applications
    1   • Priority Level   • Mobility
        • Transmission Interval   • Visibility
    2 Roaming Status Roaming Status
    3 Access Type Access Type
    4 Access Classes Access Classes


    [0021] Within each layer, access control rules are based on certain device-specific and/or application -specific attributes. Different attributes may be applied for user plane and control plane applications. For example, the embodiments illustrated in Table 1 uses different attributes for user plane and control plane applications in the first access control layer. In other layers, the attributes used for access control may be the same for both user plane and control plane applications. However, it will be appreciated that different rules may still be applied for user plane and control plane applications.

    [0022] In the exemplary embodiment illustrated by Table 1, access control rules are based on a priority level and transmission time interval attribute for user plane applications in the first access control layer. The priority level attribute indicates the relative importance of the application and the transmission interval attribute indicates the frequency of data transmission by the application. For control plane applications, the access control rules for the first access control layer are based on a mobility attribute indicating the degree of mobility of the MTC device, and a visibility attribute indicating the degree of visibility of the MTC device.

    [0023] Access attempts that are not barred by the first access control layer are subject to the second layer of access control. In the exemplary embodiment, the second layer of access control is based on the roaming status attribute. The roaming status indicates whether the MTC device or associated access terminal is located in a home network, visited network, or equivalent network.

    [0024] Access attempts that are not barred by the first and second access control layers are subject to a third layer of access control. In the third access control layer, access control rules are based on an access type attribute indicating whether the MTC device or associated access terminal is attempting system access autonomously or in response to being solicited (i.e., polled or paged).

    [0025] Access attempts that are allowed by the first three access control layers can be considered by the operator to have equal importance. These equally important access attempts may be subject to a final layer of access control, depending on the load on the RACH. As one example, access class barring rules may be applied to all access attempts allowed by the first three access control layers to limit access to a predetermined percentage of the MTC devices that pass through the first three access control layers. Access class barring is described in a U.S. Patent Application titled "ACCESS CONTROL FOR MACHINE-TYPE COMMUNICATION DEVICES" which is filed on the same date as this application and identified by attorney docket number 4015-7289. This application is incorporated herein in its entirety by reference.

    [0026] With the multi-layered access control scheme, network operators are provided with the ability to bar system access by MTC devices with fine granularity. The layered access control scheme also provides the network operator with the ability to determine what types of network accesses are barred at any point in time and the period for which the barring is to be applied. Barring may be applied separately to user plane and control plane applications. The following is a more detailed description of one exemplary access control scheme.

    [0027] The first layer of access control is based on application attributes for user plane applications. Each user plane MTC application has a corresponding priority level attribute and a transmission interval attribute. The priority level attribute indicates the importance of the MTC application. Each user plane MTC application is assigned a priority level. The priority level may be preprogrammed into the MTC device, or may be assigned by the MTC server 30. For example, the MTC server 30 may assign each MTC application a priority level when an MTC device is activated or when an MTC device registers with the MTC server 30. It should be noted that an MTC device 100 may support multiple MTC applications. Different MTC applications hosted by the same MTC device may have different priority levels. However, in some cases, it may be appropriate to associate a single priority level to all MTC applications on a given MTC device.

    [0028] Table 2 below provides one example of priority levels according to one embodiment of the invention. In this example, there are four priority levels enumerated 1-4, with 1 being the highest. Priority level 1 is for public safety applications. These applications are real-time applications with a maximum tolerable delay in the order of seconds. Priority levels 2-4 are for other MTC applications and are based on the delay tolerance of the MTC application. Priority level 2 is for minimum delay tolerant MTC applications. These MTC applications are typically real-time applications with a maximum tolerant delay in the order of seconds. Priority level 3 is for medium delay tolerant MTC applications. These applications are typically non-real time and have a maximum tolerant delay in the order of minutes. Priority level 4, the lowest priority level, is for maximum delay tolerant MTC applications. These applications are typically non-real time and have a tolerable delay in the order of hours.
    Table 2 - Priority Level Attribute
    Priority Level ValuesPriority Level CategoriesDescription
    1 Public Safety Real-time, maximum delay in the order of seconds
    2 Minimum Delay Tolerant Real-time, maximum delay in the order of seconds
    3 Medium Delay Tolerant Real-time, maximum delay in the order of minutes
    4 Maximum Delay Tolerant Real-time, maximum delay in the order of hours


    [0029] The four priority levels described above can be common to all networks such that each MTC application must be assigned one of these four priority levels before it can access the network 10 to send or receive application data. The base station 20 can selectively bar access attempts by MTC devices based on the priority level of the application attempting to send data. As an example, the base station 20 could permit access attempts by MTC devices for applications with priority levels 1 and 2, while barring access attempts by MTC devices for applications with priority levels 3 and 4. For each priority level, the base station 20 may send an access control bit in system information to the MTC device or associated access terminal. The access control bit may be set to a value of "0" to permit access and to a value of "1" to bar access.

    [0030] Each MTC application may also be assigned a transmission interval attribute. The transmission interval attribute indicates the frequency of transmissions triggered by the application. In one exemplary embodiment, three different transmission intervals denoted as "high," "medium," and "low" are defined as shown in Table 3. The high transmission interval is for MTC applications that transmit frequently in the order of seconds. The medium transmission interval is for MTC applications whose transmissions are spaced in the order of minutes. The low transmission interval is for MTC applications whose transmissions are spaced in the order of hours.
    Table 3 - Transmission Interval Attribute
    Transmission Interval CategoriesDescription
    High Frequent transmissions in the order of seconds
    Medium Frequent transmissions in the order of minutes
    Low Infrequent transmissions in the order of hours


    [0031] As with the priority level attribute, the network operator may require each MTC application to be assigned a transmission interval attribute before the MTC application is allowed to send application data. The base station 20 can therefore selectively bar access attempts by MTC devices based on the transmission interval attribute. For example, the base station 20 could allow access attempts by MTC devices for applications with high or medium transmission intervals, while barring access attempts by MTC devices for applications with a low transmission interval. An access control bit can be associated with each transmission interval category and transmitted to the MTC device or associated access terminal along with other system information.

    [0032] For control plane applications, such as non-access stratum (NAS) signaling applications on MTC devices, a different set of access control rules may be applied by the first access control layer. The MTC device may, for example, need to perform periodic NAS signaling with a serving GSM/EDGE support node (SGSN), mobile switching center (MSC), or MTC server 30. The NAS signaling may be used for establishing, terminating, and maintaining communication sessions, or to update the location of the MTC device. Different types of MTC devices will generate different amounts of NAS signaling by the control plane applications within the MTC device or associated access terminal.

    [0033] In the exemplary embodiment, two attributes are defined for controlling access by control pane applications. More particularly, the exemplary embodiment defines a mobility attribute and a visibility attribute. The mobility attribute indicates the amount of roaming that is expected by the MTC device. MTC devices that are expected to experience frequent roaming will generate greater NAS signaling mode by control plane applications than MTC devices that are expected to roam infrequently. For example, an MTC device that is disposed in a vehicle may be expected to change location frequently. On the other hand, some MTC devices may change location only infrequently (e.g., when the MTC device is redeployed). The visibility attribute indicates whether the attachment to the network by the MTC device or associated access terminal is persistent. An MTC device that remains attached indefinitely will have high visibility, while an MTC device that attaches only when necessary to send messages and detaches when message are sent will have low visibility. Applications on low visibility MTC devices will typically generate a significant amount of NAS signaling (e.g., GSM/EDGE attach signaling), depending on how often the MTC devices need to send or receive data.

    [0034] The mobility and visibility attributes indicate the amount of overhead that is expected to be generated by a control plane application in an MTC device or associated access terminal. The base station 20 may selectively bar access attempts based on the mobility and/or visibility attributes. For example, a network operator may decide to limit access attempts by control plane applications on high mobility and/or low visibility MTC devices in order to limit the overhead generated by such applications.

    [0035] Table 4 provides one example of access control rules based on mobility and/or visibility attributes according to one embodiment. As shown in Table 4, twelve NAS signaling categories are defined based on the mobility and/or visibility attributes. The base station 20 may selectively bar access to the network based on the signaling category by transmitting an access control bit for each signaling category to the MTC device 100.
    Table 4 - Mobility/Visibility attribute
    NAS Signaling CategoriesSignaling TypeAttribute
    1 PS Domain attach signaling Low Visibility
    2 PS Domain attach signaling High Visibility
    3 CS Domain attach signaling Low Visibility
    4 CS Domain attach signaling High Visibility
    5 Routing Area update signaling Low Mobility
    6 Routing Area update signaling High Mobility
    7 Location Area update signaling Low Mobility
    8 Location Area update signaling High Mobility
    9 MTC server signaling Low Mobility
    10 MTC server signaling High Mobility
    11 MTC server signaling Low Visibility
    12 MTC server signaling High Visibility


    [0036] The second layer of access control is based on a roaming status attribute that indicates whether the MTC device is currently within a home network, visited network, or equivalent network. The base station 20 can selectively bar access, depending on the roaming status attribute. A separate access control bit may be associated with each possible roaming status and transmitted to the MTC device with system information. In some embodiments, a single access control bit for each possible roaming status may be used for both MTC user plane applications and control plane applications. In other embodiments, a separate access control bit for each possible roaming status may be used to independently control access for purposes of sending user plane application data and control plane application data.

    [0037] The third access control layer includes access control rules for barring access based on an access type attribute. The access type attribute indicates whether the access attempt is autonomous or is solicited in response to a previous message from the MTC server 30 or network 12. The base station 20 can selectively bar access attempts by MTC devices depending on the whether the access attempt is autonomous or solicited. As the system loading increases, the base station 20 may, for example, bar autonomous system accesses by the MTC devices while allowing solicited system access. When system loading is low, the base station 20 may allow both autonomous and solicited access attempts. Two access control bits may be transmitted by the base station 20, along with system information to selectively bar access based on whether the access attempt is autonomous or solicited: one bit to control autonomous access attempts and one bit to control solicited access attempts. In some embodiments, the same access control bits may be used for both MTC user plane applications and control plane applications. In other embodiments, separate access control bits may be used to independently control access for user plane and control plane applications.

    [0038] In the exemplary embodiment, access attempts that are allowed by the first three layers of access control can be considered to be of equal importance to the network operator. The fourth and final layer of access control layer according to the exemplary embodiment provides the network operator the ability to permit or bar a variable percentage of access attempts of these equally important network accesses. As one example, each MTC device or associated access terminal may be assigned to an access class. In one exemplary embodiment, ten access classes enumerated 0-9 are defined. The assignment of an MTC device to an access class is based on the last digit of the device identity, such as the International Mobile Subscriber Identity (IMSI). This approach divides the MTC devices into ten substantially equal size access classes. An access control bit is associated with each access class. Thus, the base station 20 can control the number of access attempts by selectively barring one or more access classes. To be fair, a rotating mask may be used to bar access by devices or terminals associated with one or more access classes so that MTC devices in all access classes have equal opportunity to access the network 10.

    [0039] In some embodiments of the invention, the access control layers can be selectively enabled and disabled by the base station 20, depending on a type of application attempting to access the network 10. When an access control layer is enabled, the access control rules for the access control layer are applied. Conversely, when a layer is disabled, the access control rules are not applied. In some embodiments of the invention, an enablement signal may be used to selectively enable and disable specific rule sets within a layer. For example, a first enablement signal may be used to selectively enable the rule set in the first access control layer based on the priority level attribute, and a second enablement signal may be used to selectively enable the rule set in the first access control layer based on the transmission interval attribute. Table 5 below shows one example of the selective enablement of access control layers for user plane application data.



    [0040] In this example, three application types are defined: public safety application, real time MTC application, and non-real time MTC application. For each application type, a 4-bit enablement signal is used to enable/disable the layers and/or rule sets in a layer. The first two bits selectively enable the priority level rule set and the transmission interval rule set in the first access control layer. The third and fourth bits selectively enable the second and third access control layers, respectively. The base station 20 can transmit the enablement signal to the MTC device or associated MTC device 100 along with system information to selectively enable the access control layers and/or rule sets for MTC applications.

    [0041] Table 6 below illustrates an exemplary method for selectively enabling access control layers for control plane applications.



    [0042] In this example, three types of control plane applications are defined: SGSN signaling, MSC signaling, and MTC server signaling. For each application type, a 3-bit enablement signal is used to selectively enable the first, second, and third access control layers, respectively.

    [0043] It should be noted that in the example described, the fourth access control layer is applied to all applications. It will be appreciated, however, that the fourth access control layer could also be selectively enabled and disabled as previously described.

    [0044] The access control scheme as previously described can be used by a base station 20 to limit access to the network, depending on the load as seen by the base station 20. Additionally, the Serving GSM/EDGE Support Node (SGSN) in the core network 12 may indicate to the base station 20 its loading status. In one exemplary embodiment, the base station 20 may consider the load status indication from the SGSN for access control. The base station 20 may thus limit access based on loading at either the base station 20, the SGSN, or both. As one example, NAS signaling can be restricted based on an indication from the SGSN that the processing load is high. A load status indication from the SGSN may thus be used to influence the access control implemented by the base station 20.

    [0045] Fig. 4 illustrates an exemplary access control procedure 300 implemented by a base station 20. The procedure 400 begins when an access control update is triggered (block 402). The base station 20 may be configured to update the access control rules at predetermined time intervals or time of day, or in response to predetermined events. For example, the update procedure may be triggered at a periodic time interval or in response to changes in the load at the base station 20 and/or SGSN.

    [0046] When the update is triggered (block 402), the base station 20 selectively enables the access control layers for each one of a plurality of different application types (block 404). As previously noted, the base station 20 may enable a different set of layers for different application types. The base station 20 then signals the enabled access control layers for each application type to the MTC devices or associated access terminals (block 406). In some embodiments, the base station 20 may set the access control rules for each of the enabled access control layers. As an example, if the first access control layer is enabled, the base station 20 may set the access control bits for each priority level and/or transmission interval. The base station 20 then signals the access control rules for each access control layer that is enabled. By selectively enabling different access control layers for different application types, the base station 20 can more effectively manage the load on the base station 20 and/or SGSN generated by MTC devices generated by different types of MTC applications. Each access control layer also provides rules for restricting access.

    [0047] Fig. 3 illustrates an exemplary access control procedure 300 implemented by an access control function in an MTC device 100. The procedure begins when an application requests access to send data (block 302). The application may comprise a user plane or a control plane application. When an application requests network access, the access control function in the MTC device 100 determines the application type of the application requesting network access (block 304), and determines the access control layers enabled for the application type (block 306). The access control function then applies the access control rules for the enabled access control layers (block 308). As previously described, network access is permitted only if the access is allowed by all enabled access control layers. If any single access control layer bars access, then access is prohibited.

    [0048] Fig. 5 illustrates an exemplary wireless terminal 100 that may function as an MTC device, non-MTC device, or both. The wireless terminal 100 includes a processing circuit 110 connected to a transceiver circuit 150 that communicates with base stations 20 in the mobile communication network 10. The processing circuit 110 includes an access control processor 120 and memory 130 for storing program code 140 controlling operation of the wireless terminal 100. The program code 140 includes code for performing the access control functions as herein described. The transceiver circuit 150 comprises a receiver 160 and transmitter 170 for communicating with the base station 20. The transceiver circuit 150 may operate, for example, according to the GSM/EDGE standard or other communication standard.

    [0049] Fig. 6 illustrates an exemplary base station 20 that implements the access control functions as herein described. The base station 20 includes a processing circuit 30 connected to a wireless transceiver circuit 50 that communicates with wireless terminals 100 in the mobile communication network 10, and a network interface 95. The processing circuit 30 includes an access control processor 40 and memory 50 for storing program code 60 controlling operation of the base station 20. The program code 60 includes code for performing the access control functions as herein described. The transceiver circuit 70 comprises a receiver 80 and transmitter 90 for communicating with the base station 20. The transceiver circuit 70 may operate, for example, according to the GSM/EDGE standard or other communication standard. The network interface 95 enables the base station 20 to communicate with other base stations 20 and network nodes within the core network 12.

    [0050] The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.


    Claims

    1. An access control method (300) implemented by wireless terminal (100) in a mobile communication network (10), said method comprising:

    determining (304) an application type for an application that is attempting to access said communication network; characterized by determining (306) which of two or more ordered access control layers are enabled for the application type, wherein each access control layer comprises one or more sets of access control rules; applying (308), in order by layer, the access control rules for the enabled access control layers to control access to the network by the application.


     
    2. The method of claim 1 wherein applying access control rules for the enabled access control layers to control access to the network by the application comprises:

    applying the access control rules for each access control layer beginning with a first layer; and

    applying the access control rules for each subsequent access control layer only if access is not restricted by the preceding access control layer.


     
    3. The method of claim 2 wherein a first access control layer comprises access control rules based on one or more application attributes, and wherein applying the access control rules for the enabled access control layers comprises determining one or more application attributes for the application and controlling access based on the application attributes when the first access control layer is enabled.
     
    4. The method of claim 3 wherein the first access control layer comprises a first set of access control rules based on first application attributes for user plane applications and a second set of access control rules based on second application attributes for control plane applications,wherein the application attributes for user plane applications include at least one of a priority level attribute and a transmission interval attribute, and the application attributes for control plane applications include at least one of a mobility attribute and a visibility attribute.
     
    5. The method of claim 2 wherein a second access control layer comprises access rules for controlling access based on a roaming status attribute.
     
    6. The method of claim 2 including a third access control layer comprising access control rules for controlling access based on an access type attribute.
     
    7. The method of claim 2 wherein a final one of said access control layers comprises access control rules for controlling access based on an access class of said access terminal,
    wherein controlling access based on the access class of the access terminal comprises:

    determining an access class for the access terminal; and

    determining an applicable access control mask, said access control mask comprising a plurality of access control bits indicating whether respective access classes are allowed to access the communication network; and

    controlling access to the network based on the determined access class and the applicable access control mask.


     
    8. A wireless terminal (100) in a mobile communication network, said wireless terminal comprising:

    a transceiver (150) for communicating with a base station in a communication network;

    a control unit (110) connected to the transceiver for controlling access to the communication network by an application attempting to access the communication network, said control unit including a processor (120) configured to:

    determine (304) an application type for the application;

    and characterized by:

    determining (306) which of two or more ordered access control layers are enabled for the application type, wherein each access control layer comprises one or more sets of access control rules; and applying (308), in order by layer, the access control rules for the enabled access control layers to control access to the network by the application.


     
    9. A method (400) implemented by a base station (20) in a mobile communication network of controlling access to a communication network by applications, said method characterized by :

    for each one of a plurality of application types, selectively enabling (404) one or more ordered access control layers based on an application type, each access control layer comprising a set of access control rules; and

    signaling (406) the enabled access control layers for each application type to access terminals associated with said applications.


     
    10. The method of claim 9 wherein selectively enabling one or more access control layers based on an application type comprises:

    selectively enabling access control layers for user plane applications; and

    selectively and independently enabling access control layers for control plane applications.


     
    11. The method of claim 9 wherein selectively enabling one or more access control layers based on an application type comprises selectively enabling a first access control layer including access control rules based on one or more application attributes.
     
    12. The method of claim 9 wherein selectively enabling one or more access control layers based on an application type further comprises selectively enabling a second access control layer including access control rules based on a roaming status attribute.
     
    13. The method of claim 9 wherein selectively enabling one or more access control layers based on an application type further comprises selectively enabling a third access control layer including access control rules based on one or more access type attributes.
     
    14. The method of claim 9 further comprising:

    determining an access control mask for final layer of access control, said access control mask comprising a plurality of access control bits indicating whether respective access classes are allowed to access the communication network; and

    transmitting the access control mask to the access terminals.


     
    15. A base station (20) in a communication network, said base station comprising:

    a transceiver (70) for communicating with one or more access terminals (100);

    a control unit (30) connected to the transceiver for controlling access to the a communication network by an application, said control unit including a processor characterized by :

    for each one of a plurality of application types; selectively enabling (404) one or more ordered access control layers based on an application type, each access control layer comprising a set of access control rules; and

    signaling (406) the enabled access control layers for each application type to access terminals hosting applications accessing the communication network.


     


    Ansprüche

    1. Zugriffssteuerungsverfahren (300), implementiert durch ein drahtloses Endgerät (100) in einem Mobilkommunikationsnetzwerk (10), wobei das Verfahren umfasst:

    Bestimmen (304) eines Anwendungstyps für eine Anwendung, die versucht, auf das Kommunikationsnetzwerk zuzugreifen;

    gekennzeichnet durch:

    Bestimmen (306), welche von zwei oder mehr geordneten Zugriffssteuerungsschichten für den Anwendungstyp aktiviert sind, worin jede Zugriffssteuerungsschicht eine oder mehrere Mengen von Zugriffssteuerungsregeln umfasst;

    Anwenden (308) der Zugriffssteuerungsregeln für die aktivierten Zugriffssteuerungsschichten in der Reihenfolge der Schichten, um den Zugriff auf das Netzwerk durch die Anwendung zu steuern.


     
    2. Verfahren nach Anspruch 1, worin das Anwenden von Zugriffssteuerungsregeln für die aktivierten Zugriffssteuerungsschichten, um den Zugriff auf das Netzwerk durch die Anwendung zu steuern, umfasst:

    Anwenden der Zugriffssteuerungsregeln für jede Zugriffssteuerungsschicht, beginnend mit einer ersten Schicht; und,

    Anwenden der Zugriffssteuerungsregeln für jede nachfolgende Zugriffssteuerungsschicht nur dann, wenn der Zugriff nicht durch die vorhergehende Zugriffssteuerungsschicht eingeschränkt wird.


     
    3. Verfahren nach Anspruch 2, worin eine erste Zugriffssteuerungsschicht Zugriffssteuerungsregeln umfasst, die auf einem oder mehreren Anwendungsattributen beruhen, und worin das Anwenden der Zugriffssteuerungsregeln für die aktivierten Zugriffssteuerungsschichten umfasst: Bestimmen von einem oder mehreren Anwendungsattributen für die Anwendung und Steuern des Zugriffs beruhend auf den Anwendungsattributen, wenn die erste Zugriffssteuerungsschicht aktiviert ist.
     
    4. Verfahren nach Anspruch 3, worin die erste Zugriffssteuerungsschicht eine erste Menge von Zugriffssteuerungsregeln, die auf ersten Anwendungsattributen für Benutzerebenenanwendungen beruhen, und eine zweite Menge von Zugriffssteuerungsregeln, die auf zweiten Anwendungsattributen für Steuerungsebenenanwendungen beruhen, umfasst, worin die Anwendungsattribute für Benutzerebenenanwendungen mindestens eines von einem Prioritätsniveauattribut und einem Übertragungsintervallattribut einschließen und die Anwendungsattribute für Steuerungsebenenanwendungen mindestens eines von einem Mobilitätsattribut und einem Sichtbarkeitsattribut einschließen.
     
    5. Verfahren nach Anspruch 2, worin eine zweite Zugriffssteuerungsschicht Zugriffssteuerungsregeln zum auf einem Roamingstatusattribut beruhenden Steuern des Zugriffs umfasst.
     
    6. Verfahren nach Anspruch 2, eine dritte Zugriffssteuerungsschicht einschließend, die Zugriffssteuerungsregeln zum auf einem Zugriffstypattribut beruhenden Steuern des Zugriffs umfasst.
     
    7. Verfahren nach Anspruch 2, worin eine letzte der Zugriffssteuerungsschichten Zugriffssteuerungsregeln zum auf einer Zugriffsklasse des Zugriffsendgeräts beruhenden Steuern des Zugriffs umfasst, worin das auf der Zugriffsklasse des Zugriffsendgeräts beruhende Steuern des Zugriffs umfasst:

    Bestimmen einer Zugriffsklasse für das Zugriffsendgerät; und

    Bestimmen einer anwendbaren Zugriffssteuerungsmaske, wobei die Zugriffssteuerungsmaske eine Vielzahl von Zugriffssteuerungsbits umfasst, die angeben, ob jeweiligen Zugriffsklassen gestattet ist, auf das Kommunikationsnetzwerk zuzugreifen; und

    auf der bestimmten Zugriffsklasse und der anwendbaren Zugriffssteuerungsmaske beruhendes Steuern des Zugriffs auf das Netzwerk.


     
    8. Drahtloses Endgerät (100) in einem Mobilkommunikationsnetzwerk, wobei das drahtlose Endgerät umfasst:

    einen Sendeempfänger (150) zum Kommunizieren mit einer Basisstation in einem Kommunikationsnetzwerk;

    eine mit dem Sendeempfänger verbundene Steuerungseinheit (110) zum Steuern des Zugriffs auf das Kommunikationsnetzwerk durch eine Anwendung, die versucht, auf das Kommunikationsnetzwerk zuzugreifen, wobei die Steuerungseinheit einen Prozessor (120) einschließt, der dafür konfiguriert ist:

    einen Anwendungstyp für die Anwendung zu bestimmen (304); und

    gekennzeichnet ist durch:

    Bestimmen (306), welche von zwei oder mehr geordneten Zugriffssteuerungsschichten für den Anwendungstyp aktiviert sind, worin jede Zugriffssteuerungsschicht eine oder mehrere Mengen von Zugriffssteuerungsregeln umfasst; und

    Anwenden (308) der Zugriffssteuerungsregeln für die aktivierten Zugriffssteuerungsschichten in der Reihenfolge der Schichten, um den Zugriff auf das Netzwerk durch die Anwendung zu steuern.


     
    9. Verfahren (400), implementiert durch eine Basisstation (20) in einem Mobilkommunikationsnetzwerk, zum Steuern des Zugriffs auf ein Kommunikationsnetzwerk durch Anwendungen, wobei das Verfahren gekennzeichnet ist durch:

    für jeden aus einer Vielzahl von Anwendungstypen selektiv erfolgendes auf einem Anwendungstyp beruhendes Aktivieren (404) einer oder mehrerer geordneter Zugriffssteuerungsschichten, wobei jede Zugriffssteuerungsschicht eine Menge von Zugriffssteuerungsregeln umfasst; und

    Signalisieren (406) der aktivierten Zugriffssteuerungsschichten für jeden Anwendungstyp an Zugriffsendgeräte, die mit den Anwendungen assoziiert sind.


     
    10. Verfahren nach Anspruch 9, worin das auf einem Anwendungstyp beruhende selektiv erfolgende Aktivieren einer oder mehrerer Zugriffssteuerungsschichten umfasst:

    selektiv erfolgendes Aktivieren von Zugriffssteuerungsschichten für Benutzerebenenanwendungen; und

    selektiv und unabhängig erfolgendes Aktivieren von Zugriffssteuerungsschichten für Steuerungsebenenanwendungen.


     
    11. Verfahren nach Anspruch 9, worin das auf einem Anwendungstyp beruhende selektiv erfolgende Aktivieren einer oder mehrerer Zugriffssteuerungsschichten umfasst: selektiv erfolgendes Aktivieren einer ersten Zugriffssteuerungsschicht, die Zugriffssteuerungsregeln einschließt, die auf einem oder mehreren Anwendungsattributen beruhen.
     
    12. Verfahren nach Anspruch 9, worin das auf einem Anwendungstyp beruhende selektiv erfolgende Aktivieren einer oder mehrerer Zugriffssteuerungsschichten ferner umfasst: selektiv erfolgendes Aktivieren einer zweiten Zugriffssteuerungsschicht, die Zugriffssteuerungsregeln einschließt, die auf einem Roamingstatusattribut beruhen.
     
    13. Verfahren nach Anspruch 9, worin das auf einem Anwendungstyp beruhende selektiv erfolgende Aktivieren einer oder mehrerer Zugriffssteuerungsschichten ferner umfasst: selektiv erfolgendes Aktivieren einer dritten Zugriffssteuerungsschicht, die Zugriffssteuerungsregeln einschließt, die auf einem oder mehreren Zugriffstypattributen beruhen.
     
    14. Verfahren nach Anspruch 9, ferner umfassend:

    Bestimmen einer Zugriffssteuerungsmaske für eine letzte Schicht der Zugriffssteuerung, wobei die Zugriffssteuerungsmaske eine Vielzahl von Zugriffssteuerungsbits umfasst, die angeben, ob jeweiligen Zugriffsklassen gestattet ist, auf das Kommunikationsnetzwerk zuzugreifen; und

    Übertragen der Zugriffssteuerungsmaske zu den Zugriffsendgeräten.


     
    15. Basisstation (20) in einem Kommunikationsnetzwerk, wobei die Basisstation umfasst:

    einen Sendeempfänger (70) zum Kommunizieren mit einem oder mehreren Zugriffsendgeräten (100);

    eine mit dem Sendeempfänger verbundene Steuerungseinheit (30) zum Steuern des Zugriffs auf das Kommunikationsnetzwerk durch eine Anwendung, wobei die Steuerungseinheit einen Prozessor einschließt, der gekennzeichnet ist durch:

    für jeden aus einer Vielzahl von Anwendungstypen selektiv erfolgendes auf einem Anwendungstyp beruhendes Aktivieren (404) einer oder mehrerer geordneter Zugriffssteuerungsschichten, wobei jede Zugriffssteuerungsschicht eine Menge von Zugriffssteuerungsregeln umfasst; und

    Signalisieren (406) der aktivierten Zugriffssteuerungsschichten für jeden Anwendungstyp an Zugriffsendgeräte, die Anwendungen hosten, die auf das Kommunikationsnetzwerk zugreifen.


     


    Revendications

    1. Procédé de commande d'accès (300) mis en oeuvre par un terminal sans fil (100) dans un réseau de communication mobile (10), ledit procédé comprenant l'étape ci-dessous consistant à :

    déterminer (304) un type d'application pour une application qui tente d'accéder audit réseau de communication ;

    caractérisé par l'étape consistant à :

    déterminer (306) quelles couches, parmi deux couches de commande d'accès ordonnées ou plus, sont activées pour le type d'application, dans lequel chaque couche de commande d'accès comprend un ou plusieurs ensembles de règles de commande d'accès ;

    appliquer (308), dans un ordre par couche, les règles de commande d'accès pour les couches de commande d'accès activées, en vue de commander l'accès au réseau par l'application.


     
    2. Procédé selon la revendication 1, dans lequel l'étape consistant à appliquer les règles de commande d'accès pour les couches de commande d'accès activées, en vue de commander l'accès au réseau par l'application, comprend les étapes ci-dessous consistant à :

    appliquer les règles de commande d'accès pour chaque couche de commande d'accès en commençant par une première couche ; et

    appliquer les règles de commande d'accès pour chaque couche de commande d'accès subséquente uniquement si l'accès n'est pas limité par la couche de commande d'accès précédente.


     
    3. Procédé selon la revendication 2, dans lequel une première couche de commande d'accès comporte des règles de commande d'accès basées sur un ou plusieurs attributs d'application, et dans lequel l'étape consistant à appliquer les règles de commande d'accès pour les couches de commande d'accès activées comprend l'étape consistant à déterminer un ou plusieurs attributs d'application pour l'application et à commander l'accès sur la base des attributs d'application lorsque la première couche de commande d'accès est activée.
     
    4. Procédé selon la revendication 3, dans lequel la première couche de commande d'accès comporte un premier ensemble de règles de commande d'accès basé sur des premiers attributs d'application pour des applications de plan utilisateur, et un second ensemble de règles de commande d'accès basé sur des seconds attributs d'application pour des applications de plan de commande, dans lequel les attributs d'application pour les applications de plan utilisateur incluent au moins l'un parmi un attribut de niveau de priorité et un attribut d'intervalle de transmission, et les attributs d'application pour les applications de plan de commande incluent au moins l'un parmi un attribut de mobilité et un attribut de visibilité.
     
    5. Procédé selon la revendication 2, dans lequel une deuxième couche de commande d'accès comporte des règles d'accès pour commander l'accès sur la base d'un attribut d'état d'itinérance.
     
    6. Procédé selon la revendication 2, incluant une troisième couche de commande d'accès comprenant des règles de commande d'accès pour commander l'accès sur la base d'un attribut de type d'accès.
     
    7. Procédé selon la revendication 2, dans lequel une dernière couche desdites couches de commande d'accès comporte des règles de commande d'accès pour commander l'accès sur la base d'une classe d'accès dudit terminal d'accès ;
    dans lequel l'étape de commande de l'accès sur la base de la classe d'accès du terminal d'accès comprend les étapes ci-dessous consistant à :

    déterminer une classe d'accès pour le terminal d'accès ; et

    déterminer un masque de commande d'accès applicable, ledit masque de commande d'accès comprenant une pluralité de bits de commande d'accès indiquant si des classes d'accès respectives sont activées à accéder au réseau de communication ; et

    commander l'accès au réseau sur la base de la classe d'accès déterminée et du masque de commande d'accès applicable.


     
    8. Terminal sans fil (100) dans un réseau de communication mobile, ledit terminal sans fil comprenant :

    un émetteur-récepteur (150) destiné à communiquer avec une station de base dans un réseau de communication ;

    une unité de commande (110) connectée à l'émetteur-récepteur pour commander l'accès au réseau de communication par une application qui tente d'accéder au réseau de communication, ladite unité de commande incluant un processeur (120) configuré de manière à :

    déterminer (304) un type d'application pour l'application ; et

    caractérisé en ce qu'il est configuré de manière à

    déterminer (306) quelles couches parmi deux couches de commande d'accès ordonnées ou plus sont activées pour le type d'application, dans lequel chaque couche de commande d'accès comprend un ou plusieurs ensembles de règles de commande d'accès ; et

    appliquer (308), dans un ordre par couche, les règles de commande d'accès pour les couches de commande d'accès activées, en vue de commander l'accès au réseau par l'application.


     
    9. Procédé (400) mis en oeuvre par une station de base (20) dans un réseau de communication mobile, pour commander l'accès à un réseau de communication par des applications, ledit procédé étant caractérisé par les étapes ci-dessous consistant à :

    pour chaque type d'une pluralité de types d'applications, activer de manière sélective (404) une ou plusieurs couches de commande d'accès ordonnées, sur la base d'un type d'application, chaque couche de commande d'accès comprenant un ensemble de règles de commande d'accès ; et

    signaler (406) les couches de commande d'accès activées pour chaque type d'application à des terminaux d'accès associés auxdites applications.


     
    10. Procédé selon la revendication 9, dans lequel l'étape consistant à activer de manière sélective une ou plusieurs couches de commande d'accès sur la base d'un type d'application comprend les étapes ci-dessous consistant à :

    activer de manière sélective des couches de commande d'accès pour des applications de plan utilisateur ; et

    activer, de manière sélective et indépendante, des couches de commande d'accès pour des applications de plan de commande.


     
    11. Procédé selon la revendication 9, dans lequel l'étape consistant à activer, de manière sélective, une ou plusieurs couches de commande d'accès, sur la base d'un type d'application, consiste à activer de manière sélective une première couche de commande d'accès incluant des règles de commande d'accès basées sur un ou plusieurs attributs d'application.
     
    12. Procédé selon la revendication 9, dans lequel l'étape consistant à activer de manière sélective une ou plusieurs couches de commande d'accès sur la base d'un type d'application consiste en outre à activer de manière sélective une deuxième couche de commande d'accès incluant des règles de commande d'accès basées sur un attribut d'état d'itinérance.
     
    13. Procédé selon la revendication 9, dans lequel l'étape consistant à activer de manière sélective une ou plusieurs couches de commande d'accès sur la base d'un type d'application consiste en outre à activer de manière sélective une troisième couche de commande d'accès incluant des règles de commande d'accès basées sur un ou plusieurs attributs de type d'accès.
     
    14. Procédé selon la revendication 9, comprenant en outre les étapes ci-dessous consistant à :

    déterminer un masque de commande d'accès pour une couche finale de commande d'accès, ledit masque de commande d'accès comprenant une pluralité de bits de commande d'accès indiquant si des classes d'accès respectives sont activées à accéder au réseau de communication ; et

    transmettre le masque de commande d'accès aux terminaux d'accès.


     
    15. Station de base (20) dans un réseau de communication, ladite station de base comprenant :

    un émetteur-récepteur (70) destiné à communiquer avec un ou plusieurs terminaux d'accès (100) ;

    une unité de commande (30) connectée à l'émetteur-récepteur pour commander l'accès au réseau de communication par une application, ladite unité de commande incluant un processeur caractérisé en ce qu'il est configuré de manière à, pour chaque type d'une pluralité de types d'applications :

    activer de manière sélective (404) une ou plusieurs couches de commande d'accès ordonnées, sur la base d'un type d'application, chaque couche de commande d'accès comprenant un ensemble de règles de commande d'accès ; et

    signaler (406) les couches de commande d'accès activées pour chaque type d'application à des terminaux d'accès hébergeant des applications accédant au réseau de communication.


     




    Drawing





















    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description