Content for TS 22.011 Word version: 19.4.0

4 Access control p. 18

4.1 Purpose p. 18

Under certain circumstances, it will be desirable to prevent UE users from making access attempts (including emergency call attempts) or responding to pages in specified areas of a PLMN. Such situations may arise during states of emergency, or where 1 of 2 or more co-located PLMNs has failed.

Broadcast messages should be available on a cell by cell basis indicating the class(es) or categories of subscribers barred from network access.

The use of these facilities allows the network operator to prevent overload of the access channel under critical conditions.

It is not intended that access control be used under normal operating conditions.

It should be possible to differentiate access control between CS and PS domains. Details are specified in TS 23.122 and TS 25.304. Not all RATs need to support this functionality.

4.2 Allocation p. 18

All UEs are members of one out of ten randomly allocated mobile populations, defined as Access Classes 0 to 9. The population number is stored in the SIM/USIM. In addition, UEs may be members of one or more out of 5 special categories (Access Classes 11 to 15), also held in the SIM/USIM. These are allocated to specific high priority users as follows. (The enumeration is not meant as a priority sequence):

Class 15

PLMN Staff

Class 14

Emergency Services

Class 13

Public Utilities (e.g. water/gas suppliers)

Class 12

Security Services

Class 11

For PLMN Use

4.3 Operation p. 18

4.3.1 Access Class Barring |R9| p. 18

If the UE is a member of at least one Access Class which corresponds to the permitted classes as signalled over the radio interface, and the Access Class is applicable in the serving network, access attempts are allowed. Additionally, in the case of the access network being UTRAN the serving network can indicate that UEs are allowed to respond to paging and perform location registration (see, sec 3.1), even if their access class is not permitted. Otherwise access attempts are not allowed. Also, the serving network can indicate that UEs are restricted to perform location registration, although common access is permitted. If the UE responded to paging it shall follow the normal defined procedures and react as specified to any network command.

Access Classes are applicable as follows:

Classes 0 - 9

Home and Visited PLMNs;

Classes 11 and 15

Home PLMN only if the EHPLMN list is not present or any EHPLMN;

Classes 12, 13, 14

Home PLMN and visited PLMNs of home country only. For this purpose the home country is defined as the country of the MCC part of the IMSI.

Any number of these classes may be barred at any one time.

In the case of multiple core networks sharing the same access network, the access network shall be able to apply Access Class Barring for the different core networks individually.

The following are the requirements for enhanced Access control on E-UTRAN.

The serving network shall be able to broadcast mean durations of access control and barring rates (e.g. percentage value) that commonly applied to Access Classes 0-9 to the UE. The same principle as in UMTS is applied for Access Classes 11-15;
E-UTRAN shall be able to support access control based on the type of access attempt (i.e. mobile originating data or mobile originating signalling), in which indications to the UEs are broadcasted to guide the behaviour of UE. E-UTRAN shall be able to form combinations of access control based on the type of access attempt e.g. mobile originating and mobile terminating, mobile originating, or location registration. The 'mean duration of access control' and the barring rate are broadcasted for each type of access attempt (i.e. mobile originating data or mobile originating signalling);
The UE determines the barring status with the information provided from the serving network, and perform the access attempt accordingly. The UE draws a uniform random number between 0 and 1 when initiating connection establishment and compares with the current barring rate to determine whether it is barred or not. When the uniform random number is less than the current barring rate and the type of access attempt is indicated allowed, then the access attempt is allowed; otherwise, the access attempt is not allowed. If the access attempt is not allowed, further access attempts of the same type are then barred for a time period that is calculated based on the 'mean duration of access control' provided by the network and the random number drawn by the UE;
The serving network shall be able to indicate whether or not a UE shall apply Access Class Barring for SMS access attempts in SMS over SGs, SMS over IMS (SMS over IP), and SMS over S102. This indication is valid for Access Classes 0-9 and 11-15;
The serving network shall be able to indicate whether or not a UE shall apply Access Class Barring for MMTEL voice access attempts. This indication is valid for Access Classes 0-9 and 11-15:
The serving network shall be able to indicate whether or not a UE shall apply Access Class Barring for MMTEL video access attempts. This indication is valid for Access Classes 0-9 and 11-15.

4.3.2 Service Specific Access Control |R9| p. 19

Additionally to the above requirements in 4.3.1;

In E-UTRAN it shall be possible to support a capability called Service Specific Access Control (SSAC) to apply independent access control for telephony services (MMTEL) for mobile originating session requests from idle-mode and connected-mode as following:
- The serving network shall be able to indicate (as specified in subclause 4.3.1) whether or not a UE subject to SSAC shall also apply Access Class Barring.
- EPS shall provide a capability to assign a service probability factor (TS 36.331) and mean duration of access control for each of MMTEL voice and MMTEL video:
  - assign a barring rate (percentage) commonly applicable for Access Classes 0-9;
  - assign a flag barring status (barred /unbarred) for each Access Class in the range 11-15;
  - SSAC shall not apply to Access Class 10;
  - SSAC can be provided by the VPLMN based on operator policy without accessing the HPLMN;
  - SSAC shall provide mechanisms to minimize service availability degradation (i.e. radio resource shortage) due to the mass simultaneous mobile originating session requests and maximize the availability of the wireless access resources for non-barred services;
  - The serving network shall be able to broadcast mean durations of access control, barring rates for Access Classes 0-9, barring status for Access class in the range 11-15 to the UE;
  - The UE determines the barring status with the information provided from the serving network, and perform the access attempt accordingly. The UE draws a uniform random number between 0 and 1 when initiating connection establishment and compares with the current barring rate to determine whether it is barred or not. When the uniform random number is less than the current barring rate and the type of access attempt is indicated allowed, then the access attempt is allowed; otherwise, the access attempt is not allowed. If the access attempt is not allowed, further access attempts of the same type are then barred for a time period that is calculated based on the 'mean duration of access control' provided by the network and the random number drawn by the UE.

4.3.3 Access Control for CSFB |R9| p. 20

Access control for CSFB provides a mechanism to prohibit UEs to access E-UTRAN to perform CSFB. It minimizes service availability degradation (i.e. radio resource shortage, congestion of fallback network) caused by mass simultaneous mobile originating requests for CSFB and increases the availability of the E-UTRAN resources for UEs accessing other services.

When an operator determines that it is appropriate to apply access control for CSFB, the network may broadcast necessary information to provide access control for CSFB for each class to UEs in a specific area. The network shall be able to separately apply access control for CSFB, SSAC and enhanced Access control on E-UTRAN.

The following requirements apply for CSFB to 1xRTT:

In E-UTRAN, the network may apply access control for mobile originating session requests on CSFB from 1xRTT/E-UTRAN UE, The parameters received by the UE are dealt with in accordance with CDMA2000 procedures in 3GPP2 C.S0004-A [15]: "Signaling Link Access Control (LAC) Standard for cdma2000 Spread Spectrum Systems - Addendum 2".

For CSFB to UTRAN or GERAN, the necessary information in the broadcast to provide access control for CSFB is the same as that specified in Clause 4.3.1. In addition to those requirements the following apply:

Access control for CSFB shall apply for Access Class 0-9 and Access Class 11-15.It shall not apply for Access Class 10;
Access control for CSFB shall be applied for idle mode UE;
Access control for CSFB shall apply to all CSFB services;
Access control for CSFB may be provided by the VPLMN based on operator policy without accessing the HPLMN;
If Access control for CSFB, according to the UE's access class, disallows originating session requests for CSFB then a UE shall not send mobile originating session requests for CSFB;
If Access control for CSFB is applied by the UE for a mobile originating session request for CSFB, the UE shall bypass enhanced Access control on E-UTRAN for that session;
The criteria on which a UE determines whether Access control for CSFB allows or disallows originating session requests for CSFB are equivalent to those for enhanced Access control on E-UTRAN, as described in clause 4.3.1;
If access is not granted for the UE, mobile originating session requests for CSFB shall be restricted for a certain period of time to avoid overload of E-UTRAN due to continuous mobile originating session requests from the same UE. The duration of the period shall be determined using the same operation specified in Clause 4.3.1;
In case the network does not provide the Access control for CSFB information, the UE shall be subject to access class barring for Access Classes 0-9 and 11-15 as described in Clause 4.3.1.

4.3.4 Extended Access Barring |R10| p. 20

4.3.4.1 General |R11| p. 20

Extended Access Barring (EAB) is a mechanism for the operator(s) to control Mobile Originating access attempts from UEs that are configured for EAB in order to prevent overload of the access network and/or the core network. In congestion situations, the operator can restrict access from UEs configured for EAB while permitting access from other UEs. UEs configured for EAB are considered more tolerant to access restrictions than other UEs. When an operator determines that it is appropriate to apply EAB, the network broadcasts necessary information to provide EAB control for UEs in a specific area. The following requirements apply for EAB:

The UE is configured for EAB by the HPLMN;
EAB shall be applicable to all 3GPP Radio Access Technologies used in EPS or UMTS;

NOTE:
When a UE configured for EAB is located in 5G system, the UE is considered as configured for delay tolerant service.
EAB shall be applicable regardless of whether the UE is in a Home or a Visited PLMN;
A network may broadcast EAB information;
EAB information shall define whether EAB applies to UEs within one of the following categories:
1. UEs that are configured for EAB;
2. UEs that are configured for EAB and are neither in their HPLMN nor in a PLMN that is equivalent to it;
3. UEs that are configured for EAB and are neither in the PLMN listed as most preferred PLMN of the country where the UE is roaming in the operator-defined PLMN selector list on the SIM/USIM, nor in their HPLMN nor in a PLMN that is equivalent to their HPLMN;
EAB information shall also include extended barring information for Access Classes 0-9:
A UE configured for EAB shall use its allocated Access Class(es), as defined in sub-clause 4.2, when evaluating the EAB information that is broadcast by the network, in order to determine if its access to the network is barred;
If a UE that is configured for EAB answers to paging, initiates an emergency call or, is a member of an Access Class in the range 11-15 and according to clause 4.3.1 that Access Class is permitted by the network, then the UE shall ignore any EAB information that is broadcast by the network;
If the network is not broadcasting the EAB information, the UE shall be subject to access barring as described in clause 4.3.1;
If the EAB information that is broadcast by the network does not bar the UE, the UE shall be subject to access barring as described in clause 4.3.1;
In the case of multiple core networks sharing the same access network, the access network shall be able to apply the EAB for the different core networks individually.

4.3.4.2 Overriding extended access barring |R11| p. 21

Overriding Extended Access Barring is a mechanism for the operator to allow UEs that are configured for EAB to access the network under EAB conditions. The following requirements apply:

The UE configured with EAB may be configured by the HPLMN with a permission to override EAB;
For a UE configured with the permission to override EAB, the user or application (upper layers in UE) may request the UE to activate PDN connection(s) for which EAB does not apply;
The UE shall override any EAB restriction information that is broadcast by the network as long as it has an active PDN connection for which EAB does not apply.

4.3.5 Application specific Congestion control for Data Communication (ACDC) |R13| p. 21

4.3.5.1 Service description p. 21

Application specific Congestion control for Data Communication (ACDC) is an access control mechanism for the operator to allow/prevent new access attempts from particular, operator-identified applications in the UE in idle mode. ACDC does not apply to UEs in connected mode. The network can prevent/mitigate overload of the access network and/or the core network. This feature is optional.

4.3.5.2 Requirements p. 22

4.3.5.2.1 General p. 22

The following requirements apply:

This feature shall be applicable to UTRAN PS Domain and E-UTRAN;
This feature shall be applicable to UEs in idle mode only that are not a member of one or more of Access Classes 11 to 15;
ACDC shall not apply to MMTEL voice, MMTEL video, SMS over IMS (SMS over IP) emergency call and paging response;

NOTE 1:
Even if any of the above services are initiated by application, ACDC does not apply, but they are subject to other applicable access control methods.
The home network shall be able to configure a UE with at least four and a maximum of sixteen ACDC categories to each of which particular, operator-identified applications are associated. The categories shall be ordered as specified in sub-clause 4.3.5.2.2;

NOTE 2:
Provisioning of the ACDC categories in the UE is the responsibility of the home network, and the categorization is outside the scope of 3GPP.

NOTE 3:
A mechanism needs to be provided that enables the UE to verify that the provisioning of the configuration originates from a trusted source.
The serving network shall be able to broadcast, in one or more areas of the RAN, control information, indicating barring information per each ACDC category, and whether a roaming UE shall be subject to ACDC control;

NOTE 4:
The barring information may be similar to ACB information, and include mean durations of access control (i.e., barring timer) and barring rates (i.e., percentage value). If the barring timer is running due to a previous access attempt from an application in a certain given matched ACDC category, the UE may only allow access attempts from applications in higher ACDC categories (according to the corresponding barring information for those higher categories). If the barring timer is running due to a previous access attempt from an application in a certain given unmatched ACDC category or a uncategorised application, the UE may only allow access attempts from applications in higher ACDC categories than the lowest ACDC category broadcast (according to the corresponding barring information for those higher categories);
The UE shall be able to control whether or not an access attempt for a certain application is allowed, based on this broadcast barring information and the configuration of ACDC categories in the UE;
The serving network shall be able to simultaneously indicate ACDC with other forms of access control.
When both ACDC and ACB controls are indicated, ACDC shall override ACB;
If a UE is configured for both EAB and ACDC, and the serving network simultaneously broadcasts EAB information and ACDC barring information:
- If the UE determines as specified in sub-clause 4.3.4.1 that access to the network is not barred or as specified in sub-clause 4.3.4.2 that it is permitted to override an EAB restriction, then access to the network is subject to ACDC;
- If the UE determines as specified in sub-clause 4.3.4.1 that access to the network is barred and as specified in sub-clause 4.3.4.2 that it is not permitted to override the EAB restriction, then access to the network is barred.
In the case of multiple core networks sharing the same access network, the access network shall be able to apply ACDC for the different core networks individually. For the mitigation of congestion in a shared RAN, barring rates should be set equal for all Participating Operators.

4.3.5.2.2 ACDC Categories p. 22

When configuring the UE with categories of applications, the home network shall proceed as follows:

Applications whose use is expected to be restricted the least shall be assigned the highest ACDC category; and
Applications whose use is expected to be restricted more than applications in the highest category shall be assigned the second-to-highest ACDC category, and so on; and
Applications whose use is expected to be restricted the most shall either be assigned the lowest ACDC category, or not be categorised at all.

For a UE with ACDC categories configured, the applications on the UE that are not assigned to any ACDC category shall be treated by the UE as part of the lowest ACDC category broadcast by the serving network. If the operator requires differentiation with respect to these uncategorized applications, the operator should avoid assigning applications to the lowest ACDC category. When applying ACDC, the serving network broadcasts barring information starting from the highest to the lowest ACDC category. The home network and the serving network may use different categorisation. The serving network decides if ACDC applies to roaming UEs.

The number of ACDC categories in the UE may not be the same as the number of ACDC categories broadcast by the serving network. This may happen, e.g. when the UE is roaming and the number of categories broadcast by the serving network is different from the home network. Therefore, the following rules shall apply:

If the serving network broadcasts more ACDC categories than the UE's configuration, the UE shall use barring information for the matching ACDC category and shall bar uncategorised applications using the barring information for the lowest category broadcast by the serving network, and shall ignore barring information for unmatched categories.
If the serving network broadcasts barring information for fewer ACDC categories than the UE's configuration, the UE shall use barring information for the matching ACDC category and shall bar other applications using the barring information for the lowest category broadcast by the serving network.

4.3.6 Access Control for Indirect 3GPP Communications |R17| p. 23

For the case where an Evolved ProSe Remote UE is trying to access the network via an Evolved ProSe UE-to-Network Relay, the following requirements apply:

Access control for CSFB shall not apply to an Indirect 3GPP Communication;
ACB, EAB and ACDC shall apply when the Evolved ProSe UE-to-Network Relay is in IDLE mode and when the access control information for the respective access control is broadcast by the network;
SSAC shall apply when the Evolved ProSe UE-to-Network Relay is either in IDLE or CONNECTED mode and when the access control information for SSAC is broadcast by the network;
The interaction between ACDC, EAB and ACB (defined in clause 4.3.5.2.1) shall be based on the Evolved ProSe Remote UE's configuration;
During the access control procedure, the requirements in subsections of clause 4.3.1, clause 4.3.2, clause 4.3.4 and clause 4.3.5 shall be performed by Evolved Prose Remote UE using the following parameters:
- Access control parameters broadcast by the cell where the Evolved ProSe UE-to-Network Relay is camped on or connected to shall be used in all access control procedures;
- Access Class of the Evolved ProSe Remote UE shall be used;
- For ACB, the type of access attempt (i.e. mobile originating data, mobile originating signalling, response to paging or emergency call) of the Evolved ProSe Remote UE shall be used;
- For EAB, the following information shall be used:
  - Whether or not the Evolved ProSe Remote UE is configured with EAB;
  - Whether or not the Evolved ProSe Remote UE is configured with a permission to override EAB;
  - Whether the PLMN is the Evolved ProSe Remote UE's Home PLMN, equivalent PLMN or preferred PLMN. The PLMN where the Evolved ProSe UE-to-Network Relay is camped/connected shall be used to make this determination.
For SSAC, the type of access attempt (MMTEL voice or MMTEL video) of the Evolved ProSe Remote UE shall be used.
For ACDC, the ACDC category of the application that triggered the access attempt in the Evolved ProSe Remote UE shall be used.

4.4 Emergency Calls p. 24

An additional control bit known as "Access Class 10" is also signalled over the radio interface to the UE. This indicates whether or not network access for Emergency Calls is allowed for UEs with access classes 0 to 9 or without an IMSI. For UEs with access classes 11 to 15, Emergency Calls are not allowed if both "Access Class 10" and the relevant Access Class (11 to 15) are barred. Otherwise, Emergency Calls are allowed.

4.4a Multimedia Priority Service |R10| p. 24

Multimedia Priority Service (TS 22.153) shall be assigned its own unique access class value (i.e., one of the special access classes 11 to 15). The assigned access class value for Multimedia Priority Service is based on regional/national regulatory requirements and operator policy.

4.5 Control of UE Capabilities |R7| p. 24

To protect the user from the effects of a misbehaving UE (e.g. causing additional charges, degraded performance) and to protect the network operator's network capacity, including radio resources and network signalling and processing, means shall be provided for the HPLMN/EHPLMN and the VPLMN to provide an indication to the UE as to which network provided services or functions it is not allowed to use.

The Selective UE Capabilities list shall be maintained in the UE and the UE shall not request any services indicated as disabled. At registration the HPLMN/EHPLMN or VPLMN may interrogate the status of the list and provide a new list.

The Selective UE Capabilities list shall not be deleted at switch off and will remain valid until a new list is provided by the network. The Selective UE Capabilities list relates to the ME and not to the subscription.

It should be ensured that UEs are not maliciously disabled, including malicious disabling by a VPLMN, or accidentally disabled, or kept disabled, and there shall be a mechanism for restoring disabled UEs in all situations (e.g. in the case that the serving network does not support the control of UE Capabilities).

The UE should use the indications given in the Selective UE Capabilities list to inform the user of the non-availability of services or functions.

There shall be a means for the network to provide an optional customer service number(s) which can be used, by the user, to assist in determining the cause of non-availability of specific services. The specifications should also provide the capability for the network to include an optional text string that will be displayed by the UE.

The UE Capabilities list shall take precedence over subscribed services.

The services to be included in the list are:

Call Control functions;
Supplementary Services;
Emergency Calls (including the (U)SIM-less case and subject to regional regulatory requirements, i.e. emergency calls shall not be disabled in regions where support of them is required);
SMS, via CS and PS;
LCS, via CS and PS;
GPRS based services;
MBMS;
IMS.

4.6 Prevention of mobile-originating signalling and/or data traffic |R12| p. 25

The network shall be able to control the behavior of UEs in E-UTRAN in connected mode to prevent mobile originating signalling and/or data traffic, while the access barring mechanisms specified under Clause 4.3 are being applied to UEs in idle mode.