GB2443233A

GB2443233A - Network overload protection

Info

Publication number: GB2443233A
Application number: GB0620351A
Authority: GB
Inventors: Ajay Vachhani; Stuart Findlay
Original assignee: NEC Technologies UK Ltd
Current assignee: NEC Technologies UK Ltd
Priority date: 2006-10-16
Filing date: 2006-10-16
Publication date: 2008-04-30
Anticipated expiration: 2026-10-16
Also published as: GB2443233B; GB0620351D0

Abstract

The present invention provides for an access class barring arrangement for controlling load within a mobile radio communications network by signalling restriction parameters from the network to user equipment. The restriction parameters include application and procedure class data in addition to access class, so as to allow restricted use of the user equipment within otherwise barred access classes.

Description

NETWORK OVERLOAD PROTECTION

The present invention provides for an access class barring method, and related network equipment and user equipment, arranged to provide for network overload protection.

It is well recognised that an overload condition for a mobile radio communications network has a limiting effect on the overall efficiency of the network, and various user equipment devices using the same. It is also appreciated that the monitoring of network traffic, with a view to limiting the same, can prove useful in preventing, or at least limiting, the impact of a potential overload condition within the network.

An Access Class Barring (ABC) mechanism is currently employed when an overload condition within the network is identified and within which one or more of the Access Classes (ACs) employed within the network is/are barred. In this manner, User Equipment (UE) having one of these access classes is effectively barred from using the network in an attempt to overcome the overload condition.

However, it has been identified that, with the known ACB arrangement, while the barring of each AC will lead to the effective barring of a number of users from accessing the network, the actual barring of the users is somewhat indiscriminate and independent of whether or not users requiring that AC are actually attempting access to the network.

On this basis, it may well be that a disproportionate number of access attempts will be allowed/barred since the effect of the ACB cannot be immediately identified. That is, when the network bars of one particular AC the network will not be able to detennine whether any network access attempts are actually blocked since it is unknown whether or not the barred tiE devices are actually seeking access to the network. Thus, it is possible that no access attempts are being made by the barred UE at that particular time such that the barring of the AC and the related UE, then has no effect on the network overload condition.

It is likely that the network is only able to determine whether or not the ACB has had a desired effect after a short time delay within which it can be determined whether or not the ACB employed has had an impact on the rate of initial accesses. If the initial ACB step does not seem to have had an effect on the overload condition, the network will then need to commence further ACB. Again, this is likely to prove a relatively slow process and, in the meantime, the network overload condition may in fact have Insofar as ACB can be found to be indiscriminate and disproportionate at the time of barring one or more ACs, it is likewise found that, at the time of releasing one or more previously barred ACs, the network could likewise experience a disadvantageous surge in signalling, particularly in relation to delayed location updates.

The present invention seeks to provide a network overload protection arrangement having advantages over known such arrangements and which, in particular, seeks to provide for a method, and related user equipment and network devices, offering advantages over the current art.

According to a first aspect of the present invention, there is provided an Access Class Barring method for controlling load within a mobile radio communications network and including the step of signalling restriction parameters from the network to User Equipment, wherein the restriction parameters comprise access class data and application and procedure class data.

The invention is particularly advantageous insofar as use of specific application and procedure class data allows the network to readily control the nature of application data and/procedure data that can be transmitted for certain load conditions, irrespective of the nature of the ACB that might be employed at any one time.

The present invention therefore provides for a far more flexible, accurate and responsive means for controlling, and indeed monitoring, the load condition of the network whilst not suffering the disproportionate and indiscriminate barring experienced in the current art.

In particular, the restriction parameters can he signalled within a cell specific access restriction information element, or indeed any equivalent information element, to be delivered from the network to the User Equipment.

Advantageously, when the User Equipment is in idle mode, the restriction parameters can be signalled within system information block type 3 of the cell specific access restriction, or equivalent, information element. Alternatively, when the user equipment is in the connected mode, the restriction parameters are signalled on system information block type 4 contained in the cell specific access restriction, or equivalent, information element.

Yet further, the method can include the step of User Equipment reporting access class and application and procedure class data to the network.

In particular, the User Equipment reports such restriction parameters in response to a specific request from the network.

In one example, the restriction parameters can be reported from the user equipment at the time of making connection, and the restriction parameters then signalled within the initial direct transfer message, or indeed any other appropriate layer3/layer2 signalling message.

Also, the user equipment can report the restriction parameters when making further service requests while in a connected mode.

In this manner, the report from the user equipment is delivered within an uplink direct transfer message, or any other appropriate Iayer3/layer2 signalling message.

Of course, it will be appreciated that the method of the present invention can be employed for implementing, or increasing, network barring.

Alternatively, or in addition, the method can also be employed during network unbarring so as to provide for advantageously controlled reintroduction of the previously barred ACs and application and procedure class data.

Within the method, and with regard to the said user equipment reporting access class and application and procedure class data, it should be appreciated that the restriction parameter data can be employed by the network in real time or, alternatively, can be averaged over a period of time as required.

The present invention is particularly advantageous insofar as it allows for a more accurate estimation of the likely effects of ACB and on network load conditions.

As noted, when the bar is lifted, or the extent of the bar is reduced, the network can advantageously prevent possible surges in access attempts and a related overload condition, since the invention allows for the accurate identification of the possible load effects of removing, as well as introducing, barring as discussed above.

Thus, as will be appreciated, according to the present invention the user equipment is not necessarily either barred or not barred, but rather presented with an intermediate state within which the barring is only effective with regard to certain applications/certain procedures and as advantageously identified by application and procedural class data.

According to another aspect of the present invention, there is provided a mobile radio communications device for communication within a mobile radio communications network and arranged to receive restriction parameters from the network and which serve to control the load within the network, wherein the restriction parameters comprise access class data and application and procedure class data.

Again, and as noted above the invention when embodied in the above device is particularly advantageous insofar as use of specific application and procedure class data allows the network to readily control the nature of application data and/procedure data that can be transmitted across the network for certain load conditions irrespective of the nature of the ACB that might be employed at any one time.

The device can be employed in a manner providing for a far more flexible and accurate and responsive means for controlling, and indeed monitoring, the load condition of the network whilst not suffering the disproportionate and indiscriminate barring experienced in the current art.

In particular, the device is arranged to receive restriction parameters signalled within a cell specific access restriction, or equivalent, information element.

When the device is in idle mode, the restriction parameters are signalled within the system information block type 3 within the cell specific access restriction, or equivalent, information element. Alternatively, when the device is in the connected mode, the restriction parameters are signalled on the system information block type 4 contained in the cell specific access restriction, or equivalent, information element.

Yet further, the device can be arranged to report access class and application and procedure class data to the network.

In particular, the device is arranged to report such restriction parameters in response to a specific request received from the network.

In one example, the restriction parameters can be reported from the device at the time of making connection and the restriction parameters can then be signalled within the initial direct transfer message.

Also, the device can report the restriction parameters when making further service requests while in a connected mode.

In this manner, the report from the device is delivered within an uplink direct transfer message.

According to yet a further aspect of the present invention there is provided a network element for a mobile radio communications network and arranged for signalling restriction parameters to User Equipment within the network so as to control load conditions within the network, where the said restriction parameters comprise access class data and application and procedure class data.

The invention is particularly advantageous insofar as use of specific application and procedure class data allows the network element to readily control the nature of application data and/procedure data that can be transmitted across the network for certain load conditions irrespective of the nature of the ACB that might be employed at any one time.

The use of the network element therefore provides for a far more flexible and accurate and responsive means for controlling and indeed monitoring the load condition of the network whilst not suffering the disproportionate and indiscriminate barring experienced in the current art.

In particular, the network element can be arranged to signal the restriction parameters within a cell specific access restriction, or equivalent, information element.

When the user equipment is in idle mode, the restriction parameters can be signalled from the network element within the system information block type 3 within the cell specific access restriction, or equivalent, information element. Alternatively, when the user equipment is in a connccted mode, the network element can signal the restriction parameters on the system information block type 4 contained in the cell specific access restriction, or equivalent, information element.

Yet further, the user equipment can report such restriction parameters in response to a specific request received from the network element.

Again, use of the network elements of the invention is particularly advantageous insofar as it allows for a more accurate estimation of the likely effects of access class barring and on network load conditions.

Advantageously, the network element comprises a radio network controller for a UMTS network.

Alternatively, the network can comprise an eNodeB for a LTE network.

It should also be appreciated that the invention can provide for a method and related devices and network elements in which only restriction parameters comprising application and procedure class data is employed. As such, there need not be any access class barring for reducing network load.

Further, the invention can also provide for statically defined association between the application and procedure class and the application and procedure that can be utilized by a network element and user equipment.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which: Fig. I is a signalling diagram between a network and related User Equipment embodying the present invention and during an information gathering stage; Fig. 2 is a signalling diagram between the network and User Equipment as in Fig. I and when in an idle mode; Fig. 3 is a signalling diagram between the network and User Equipment as in Fig. I and in a connected mode; Fig. 4 is a table schematically illustrating network traffic as divided across a plurality of Access Classes and a plurality of application/procedure classes; Fig. 5 is a table similar to that of Fig. 4 but with an uneven traffic distribution across the Access Classes; and Fig. 6 is an illustration similar to that of Figs. 4 and 5 but in accordance with a further uneven traffic distribution.

Within the present invention, UE such as a mobile radio communications device is provided with a new data element, Application/Procedure Class (APC) based on its current service that it is planning to use e.g. VOIP. It also has an Access Class (AC) which is stored in the Subscriber Identity Module (SIM) which is provided by the operator at the time of SIM issue.

The network broadcasts the new APC information and AC on system information which the UE can use to determine if particular application/procedure will be allowed.

The information can be broadcast on system information block type 3 contained in the cell specific access restriction Information Element (IE) in idle mode, and on system information block type 4 with the UE in Connected Mode. The network signals via system information that the UE should report the AC and APC when it makes a connection in the Initial Direct Transfer message, or in an Uplink Direct Transfer when making further service requests while in connected mode.

To assist such functionality, the initial Direct Transfer Message and Uplink Direct Transfer Message can have a new element identified as Access Information which comprises an optional element based on whether the network has set the ACB field of the cell specific access restriction IE to "reporting".

The Doman Specific Access Restriction Parameters IE can be removed to retain just a cell-specific element, whilst also removing the separate CS and PS Domain elements.

According to the invention, the network can use the AC and APC to determine the loading and probability of loading when barring certain ACs and APCs.

Additionally, the network can also use the AC and APC to determine the loading, and probability of loading, when unbarring certain ACs and APCs.

The barring mechanism of the present invention is employed to protect against network overloading and can be triggered when a network threshold for overloading is detected.

The manner in which the network uses the AC and APC data is optional, for example, the network can be arranged to employ the data in real time, or employ a running average over a period of time.

As a further option, the method of the invention can be arranged simply to blindly bar certain ACs and APCs and in this manner there is no need to receive AC and APC reports from the UE.

In further detail, and turning first to Fig. 1, there is illustrated a signalling diagram for a series of signals 10 arising between a network 12 and UE 14 in the form of a mobile radio communications device such as a cell phone handset. Fig. I illustrates an information gathering stage of a method embodying the present invention. Within Fig. 1, the user equipment 14 is in idle mode and initially reads system information block type 3 16 in which the cell-specific access restriction parameters IE has a status of access class barred set at "reporting".

Radio Resource Controller (RRC) request setup and completion phase signalling 18, 20, 22 is then generated with the RRC setup phase having been entered upon user-initiation of a service such as VO1P.

Once the RRC connection and setup phase has been completed, the UE 14 then sends, as part of and an initial transfer message 24, its AC and the APC according to the data to be transmitted. The radio bearer is then setup for the relevant APC required, the network 12 advantageously employs the AC and APC data to determine a loading profile, and related loading -probability, if a bar were to be placed on the AC data and APC data concerned.

Turning now to Fig. 2, a signalling scenario is illustrated for the UE 14 of Fig. 1 while in an idle mode. The UE 14, whilst in its idle mode, is arranged to read system information block type 3 and to compare its AC and APC data against that provided within the information block type 3 signalling 26. Through such comparison, the UE can then determine whether or not its related application/procedure can be initiated for a particular access class.

As illustrated particularly with regard to Fig. 2, it will be appreciated that the information block type 3 signalling indicates restriction parameters identifying access classes 0, 1, 2, and for application/procedure classes 0, 1, 2. This means, for example, that application/procedure class 3 can still be employed even on access classes 0, 1, and 2, and that no barring whatsoever exists in relation to any remaining access classes.

Turning now to Fig. 3, the signalling scenario illustrated here relates to the UE 14 in connected mode with the network 12. In this embodiment, and in the connected mode, the UE 14 is arranged to read system information block type 4 containing signalling data 28.

The cell-specific access restriction LE within the system information block type 4 serves to identify that the access classes 0, 1, 2 and application/procedure classes 0, 1, 2 are barred. Again this means that application/procedure class 3 can still be used even in relation to access classes 0, 1, 2 and that no barring whatsoever exists in relation to the remaining access classes. Through knowledge of its own access class and the application/procedure class, the UE 14 can readily check if a new additional service can proceed or whether that new additional service will also be barred.

As described, if a further service is allowed, the network requested reporting from the user equipment 14 will employ an uplink direct transfer message 30 so as to report the AC and APC related to the other said further service.

As will be appreciated, the present invention can require, and take advantage of, new information elements within the data signalling while also employing modifications to currently existing information elements.

Such new information elements can comprise an Access Information LE, or APC barred list and a MaxAPC element. The latter two elements serve to identify a default position of no APC barring occurring, and the maximum number of application/procedure classes respectively.

With regard to the new access information JE, this can comprise a single element with 4 bits for the AC data, and a further 4 bits for the APC data. While currently known and normal AC values can remain, possible APCs can be identified as follows: APC 3: Voice, VOIP, POC APC 2: Email, SMS, MMS APC 1: Gaming. Web Browsing, FTP, Database Access. Non Periodic Location Updating.

APC 0: Video Calls, Periodic Location Updates, Video Streaming, other services It should be appreciated that the APC data can be arranged in priority with application such as browsing and FTP, i.e. those exhibiting high data requirements, being classified with the least priority, as compared with voice service application which are classified with the highest priority.

Of course the association between any particular APC, and its related application/procedures, can be defined in a predetermined static manner, or can be defined dynamically, particularly by use of system information as delivered to the UE.

Turning now to the modified information elements reference is first made to the Initial Direct Transfer message as discussed above.

The Access Information IE can be added to the Initial Direct Transfer message as follows: Information Need Multi Type and Semantics description Version Element/Group name _______ _______ reference Message Type MP Message UE Information elements Integrity check info CH Integrity check info ____________________ ______ ______ 103.3.16 ___________________ PLMN identity OP PLMN This IE indicates the PLMN to which the UE identity requests the signalling 10.3.1. Il connection to be __________________________ _______ _______ ____________ established _______________ Access information OP Access REL-7/LTE I I Information IE With regard to the Uplink Direct Transfer message, the Access Information IE can be added as shown below.

Information Need Multi Type and Semantics description Element/Group name ________ _______ reference Message Type MP Message Type UE information elements Integrity check info CH Integrity check Integrity check info is included if ______________________ ________ _______ info 10.3.3.16 integrity protection is applied Access information OP Access REL-7/LTE __________________ _______ Information IE ________________________________ CN information elements CN domain identity MP CN domain _______________________ ________ _______ identity 1O.3J I ________________________________ NAS message MP NAS message 10.3.1.8 Measurement information elements ________ _______ Measured results on OP Measured RACH results on ____________________ _______ ______ RACI-l 10.3.7.45 ____________________________ System Information Block type 3, the Cell Specific Access Restriction IE can be modified, and the Domain Specific Access Restriction Parameters as listed in the following can be removed.

Domain Specific Access Restriction OP Domain Specific This IE specifies the Domain Specific REL-6 Parameters for PLMN Of M ER Access Restriction Access Restriction Parameters for Parameters 10.3 3c UEs which has chosen the PLMN in the IE PLMN identity" of the Master information Block Domain Specific Access Restriction For OP REL-6 Shared Network >CHOICE barring representation MP REL-6 >>Domain Sped tic Access Restriction OP Domain Specific This lE specifies the Domain Specific REL- 6 Parameters For Operator I Access restriction Access Restriction Parameters for Parameters liEs which has chosen the first PLMN 103 I 3c in the IE "multiple PLMNs" in the LE Multiple PLMN List" of the Master __________________________________ _______ ____________________ Information Block ________ >>>Domain Specific Access Restriction OP Domain specific This FE specifies the Domain Specific REL-6 Parameters For Operator 2 Access Restriction Access Restriction Parametcrs for Parameters 10 3 I 3c liEs which has chosen the second PLMN in the FE "multiple PLMNs" in the FE "Multiple PLMN List" of the _____________________________ _______ ____________________ Master Information Block >>>Domain Specific Access Restriction OP Domain Specific This lE specifies the Domain Specific REL-6 Parameters For Operator 3 Access Restriction Access Restriction Parameters for Parameters 103 I.3c liEs which has chosen the third PLMN in the IE "multiple PLMNs" in the JE "Multiple PLMN List" of the __________________________________ _______ ____________________ Master information Block ________ >>>Domain Specific Access OP Domain specific This FE specifies the Domain Specific REL-6 Restriction Parameters For Operator 4 Access Restriction Access Restriction Parameters for Parameters 103 1 3c UEs which has chosen the fourth PLMN in the TE "multiple PLMNs" in the IE "Multiple PLMN List" of the _____________________________________ ________ _____________________ Master Information Block >>>Domain Specific Access Restriction OP Domain Specific This FE specifies the Domain Specific REL-6 Parameters for Access Restriction Access Restriction Parameters for Operators Parameters 103 I 3c liEs which has chosen the fifth PLMN in the FE "multiple PLMNs" in the lE "Multiple PLMN List" of the Master __________________________________ _______ ____________________ Information Block >>Domain Specific Access Restriction Parameters for All >>>Domain Specific Access Restriction Domain Specific This IE specifies the common Domain REL-6 Parameters Access Restriction specific Access Restriction Parameters Parameters 1031 3c applied to all PLMNs in the FE "multiple PLMNs" in the FE "Multiple PLMN List" of the Master __________________________________ _______ ____________________ Information Block ________ >>>Domam Specitic Access Restriction Domain Specific This lE specifies the common REL-6 Parameters Access Restriction Domain Specific Access Restriction Parameters 10 3 I 3c Parameters applied to all PLMNs in the IE "multiple PLMNs" in the IE "Multiple PLMN List" of the Master _______________________________________ _________ Information Block The Cell Specific Access Restriction JE can have its Access Class Barred field modified to remove Barred field whilst also adding the following field Unbarring and Reporting, Reporting and Barring and Reporting. In addition a Service Class Barred

list field can be added.

The Cell-Specific Access Restriction JE is then as follows: Information Element/Group Need Multi Type and reference Semantics name _________ _________ ____________________________________ description Cell Barred MP Enumerated (not barred, ban-ed) lntra-frequency cell re-CV-Enumerated (not aliosed, allowed) selection indicator Barred ___________ CV-integer 141 __________________________ Barred __________ (I0,20,40,80,160.320,640,1280) [s] Cell Reserved for operator use MP Enumerated (reserved, not reserved) Cell Reservation Extension MP Enumerated (reserved, not reserved) Access Class Barred list CV-SIB3maxAC Default is no access class MD barred is applied.

The first instance of the parameter corresponds to Access Class 0, the second to Access Class I and so on up to Access Class 15. UE reads this IE of Its access class stored in _________________________ _________ __________ ______________________________________ 51M Application and Procedure CVSiB3-macAPC Default is no application and Class Barred list MD procedure classbarred is applied.

The first instance of the parameter corresponds to APC 0,thesecondtoApC I andso ______________________ ________ ________ _________________________________ onuptoAPC 15 >Access Class Barred MP Enumerated (not barred, barring and reporting, unbarring and reporting,, _____________________________ ___________ ____________ reporting) ____________________________ The Domain Specific Access Restriction Parameters the IE specifies domain specific access class restriction parameters for use on both CS and PS domains and the following element can be removed from the specification.

Information Element/Group Need Multi Type and Semantics description Version name ________--__________ reference CS Domain Specific Access MP Domain Specific This IE contains Domain Specific REL-6 Restriction Access Restriction Access Restriction Parameters for __________________________ _______ _________ 1031 3b CS domain ___________ PS Domain Specific Access MP Domain Specific This IE contains Domain Specific REL-6 Restriction Access restriction Access Restriction Parameters for ____________________________ _______-_________ 03 l3b PS domain ___________ For Domain Specific Access Restriction, the following elements can be removed from

the specification

Information Need Multi Type and reference Semantics description Version Element/Group name _______ _________ __________________ CHOICE restriction MR REL-6 status _________ >no restriction (no data) REL-6 >restnction REL-6 >restriction REL- >> Domain Specific MD <MaxAc> The first Instance of the REL-6 Access Class Barred parameter corresponds to List access Class 0, the second to Access Class I and so on up to Access Class 15 UE reads this Ic of its access class stored in SIM The default value is the Access Control Barred Listcontained in the IF. "Cell Access Restriction" of the System Information Block _________________ _______ ________ ________________ Type 3 ______________ >>>Access Class MR Enumerated (barred, REL-6 Barred ________ ___________ not barred) _____________________________ __________________ Turning now to the System Information block type 4, the Cell Specific Access Restriction IE can be modified as described in the previous section.

As outlined previously the association between any particular APC, and its related applicationlprocedures, can be defined in a predetermined static manner, or can be defined dynamically, particularly by use of system information as delivered to the UE.

For dynamic association the application and procedure information needs to be defined. This can be a I byte value defining 256 possible applications and procedures.

An example of the applications and procedure information definition is as follows:-Application and Procedure Value Voice 0 VoIP 1 Poe _____ 2 SMS -3 MMS 4 Gamming 5 -__________ Web Browsing 6 ___________-FTP _____ 7 Database Access 8 Non Periodic Location Update 9 Video Call 10 ____________ Periodic Location Update 11 Video Streaming 12 Handover -13 Email 14 The dynamic association of application and procedure class and the application and procedure information can he transmitted using system information and may be defined as below.

The first index corresponds to APC 0, the second to APC I and so on up to APC 15.

The association contains application and procedure information expressed as bytes contained in the APC class as defined previously.

An example is as follows: APC 3: contains values 0,1,2 as defined previously APC 2: contains values 1, 4,3,4 as defined in previously APC 1: contains values 5,6,7,8,9 as defined in previously APC 0: contains values 10,11,12 as defined in previously Turning now to Fig. 4, there is provided a table illustrating network load distribution across ten different access classes and exhibiting an even traffic distribution. Thus, it will be appreciated that each of the access classes ACO -AC9 provides for 10% of the network traffic and, within each access class, that 10% is divided in the percentages illustrated. Thus, for each of the ACs, 40% of its own traffic is voice related, whereas only 20% is SMS related.

With regard to Fig. 4, if it was required for the network to reduce traffic by, for example, 40%, then in accordance with the current art, this would require the barring of, for example, Access Classes ACO-AC3. However, this leads to the potential disadvantages discussed in the introduction of the present application.

Rather, and in accordance with the present invention, the network could readily receive data concerning the different applications/procedures within each AC so that, for example, the network could serve to bar access classes ACO-AC7 with the exception of application/procedure class "voice" thereby allowing voice calls to continue across all ten ACs, even though the remaining non-voice application/procedures would only be allowed for access classes AC8 and AC9.

With regard to Fig. 5, there is illustrated a similar load distribution table but within which traffic data is unevenly distributed across the ten access classes ACO-AC9.

Again, assuming that it is identified that the network needed to reduce traffic by 20%, in accordance with the current art this could be achieved by barring access classes ACO and AC1 though this would only potentially bar 10% of the network traffic. In accordance with the present invention however, and given the additional application/procedure data, the network can readily identify that barring the traffic for access classes ACO and AC! would be insufficient to reach the required value of 20% and so, as an alternative, all of the traffic of access classes ACI and AC2 could be barred.

Turning now to Fig. 6, there is again provided a table illustrating uneven traffic distribution across the ten access classes ACO-AC9. In this case, it is identified that the network is required to unbar, or release, 30% of the network traffic. According to the current art, a determination could be made to release access classes ACO to AC2 and this would potentially release 35%. 1-lowever, this can prove inaccurate in view of the 5% difference between the potential release and required release. In the present invention however, and advantageously through analysis of the AC and APC figures, the invention can provide for the release of AC5 to AC7 which will then accurately provide the required 30% release of potential traffic.

Thus, through reference to Figs. 4 to 6 it should be appreciated that more accurate and appropriate barring can be achieved with regard to the retention of possible essential services, and/or barring and unbarring can also be provided at greater levels of accuracy It should therefore be appreciated that the present invention can provide UE which has APC based on the current application/procedure that it is intending to employ. It also has an AC which is derived from the operator at the time of SIM issue. The network broadcasts the APC information and AC on system information which the UE then uses to determine if the application/procedure will be allowed. Preferably, the network signals via system information that the UE should report the AC and APC when it makes a connection.

As noted, it is also possible for the network not to use the AC and APC data at all and hence not ask the UE to report the data and to blindly bar certain access classes and application/procedure classes.

The present invention provides for the AC and APC data to be delivered to the network in RRC signalling, and the network can also be arranged to decide whether the UE should report this information.

Again, the network can use the AC and APC to determine the loading and probability of loading when unbarring certain ACs and APCs.

Of course, the APC can comprise a combination of Circuit Switched and Packet Switched services and applications, and also signalling procedures such as location update procedures.

The invention is particularly applicable to UMTS and LTE networks, and can be stored and used by the RNC for VMTS networks, and stored and used by the eNodeB for LTE networks.

Through use of the invention, UEs are advantageously not just either barred or not barred since there is now offered an in between state where they are barred from certain specific applications and/or procedures.

Claims

1. An access class barring method for controlling load within a mobile radio communications network including the step of signalling restriction parameters from the network to User Equipment, wherein the restriction parameters comprise access class data and application and procedure class data.

2. A method as claimed in Claim 1, wherein the restriction parameters are signalled within a cell specific access restriction information element delivered from the network to the User Equipment.

3. A method as claimed in Claim 2, wherein, with the user equipment in idle mode, the restriction parameters are signalled within the system information within the cell specific access restriction information element.

4. A method as claimed in Claim 2, wherein, with the User Equipment in a connected mode, the restriction parameters are signalled on the system information contained in the cell specific access restriction information element.

5. A method as claimed in any one or more of Claims I to 4, and including the step of reporting access class and application and procedure class data from the UE to the network.

6. A method as claimed in Claim 5, wherein the User Equipment reports the said restriction parameters in response to a specific request received from the network.

7. A method as claimed in Claim 5 or 6 including reporting the restriction parameters from the user equipment at the time of making a network connection.

8. A method as claimed in Claim 7, wherein the restriction parameters are signalled within an initial direct transfer message.

9. A method as claimed in Claim 5 or 6 including reporting the restriction parameters while the UE is making further service requests while in a connected mode.

10. A method as claimed in Claim 9, wherein the report from the User Equipment is delivered within an uplink direct transfer message.

11. A method as claimed in any one or more of Claims 1 to 10, and provided for one of access class barring or unbarring.

12. A mobile radio communications device for communication within a mobile radio communications network and arranged to receive restriction parameters from the network and which serve to the control load within the network, where the restriction parameters comprise access class data and application and procedure class data.

13. A device as claimed in Claim 12 and arranged to receive restriction parameters signalled within a cell specific access restriction information element.

14. A device as claimed in Claim 13 which, when in idle mode is arranged to receive the restriction parameters within the system information within the cell specific access restriction information element.

15. A device as claimed in Claim 13 which, when in connected mode is arranged to receive the restriction parameters within the system information contained in the cell specific access restriction information element.

16. A device as claimed in any one or more of Claims 12 to 15 and arranged to report access class and application and procedure class data to the network.

17. A device as claimed in Claim 16 and arranged to report the restriction parameters in response to a specific request received from the network.

18. A network element for a mobile radio communications network and arranged for signalling restriction parameters to the network so as to control the load conditions within the network, wherein restriction parameters comprise access class data and application and procedure class data.

19. A network element as claimed in Claim 18 and arranged for signalling the restriction parameters within a cell specific access restriction information element.

20. A network element as claimed in Claim 19 and arranged, when the user equipment is in idle mode, to signal the restriction parameters within system information within the cell specific access restriction information element.

21. A network element as claimed in Claim 19 and arranged when the user equipment is in a connected mode, to signal restriction parameters on system information contained in the cell specific access restriction information element.

22. A network element as claimed in any one or more of Claims 18 to 21, and arranged to signal to user equipment within the network with a request for the restriction parameters.

23. A network element as claimed in any one or more of Claims 18 to 22, and arranged to signal to user equipment within the network a dynamic association between the application and procedure class and the application and procedure information using system information.

24. An access class barring method for controlling load within a mobile radio communications network, substantially as hereinbefore described with reference to the accompanying drawings.

25. A mobile radio communication device substantially as hereinbefore described with reference to the accompanying drawings.

26. A network element substantially as hereinbefore described with reference to the accompanying drawings.