Enhanced Coverage Restriction Control support using SCEF
enables 3rd party service providers to query status of, enhanced coverage
restriction, or enable/disable enhanced coverage restriction per individual
UEs.
The Enhanced Coverage Restriction Control procedure requested by
SCS/AS is determined from the URI as described below.
- The SCS/AS sends an
Enhanced Coverage Request (External Identifier or the MSISDN, SCS/AS
Identifier, Request Type, and Enhanced Coverage Restriction Data) message to
SCEF. Request Type indicates if the request needs to query the status, enable,
or disable the enhanced coverage restriction. Enhanced Coverage Restriction
Data provides data related to the Enhanced Coverage Restriction. Enhanced
Coverage Restriction Data is only present if the Request Type enables or
disables the enhanced coverage restriction.
- Based on operator
policies, if the SCS/AS is not authorized to perform this request, or the
Enhanced Coverage Request is malformed, or the SCS/AS has exceeded its quota or
rate of submitting Enhanced Coverage requests, SCEF performs step 9 and
provides a Cause value appropriately indicating the failure result.
- SCEF sends an Enhanced
Coverage Request (External Identifier or MSISDN Type) message to the HSS.
- HSS examines the Enhanced
Coverage Request message for the existence of an External Identifier or MSISDN,
any included parameters in the acceptable range for the operator, and the
Enhanced Coverage restriction by the serving MME/SGSN. If this check fails, the
HSS follows step 8 and provides a Cause value indicating the reason for the
failure condition to the SCEF.
If the Request Type is to get the current status of enhanced
coverage, HSS retrieves the value and follows the procedure at step 8;
otherwise, if the Type is to enable or to disable the enhanced coverage, HSS
sets the Enhanced Coverage Restricted parameter to the appropriate value and
the procedure continues with step 5.
- If required by the
specific Enhanced Coverage Request Type and when Enhanced Coverage is supported
by the serving MME/SGSN, HSS sends an Insert Subscriber Data Request (Type)
message to the MME/SGSN.
- Based on operator
policies, MME/SGSN may reject the request (for example, for an overload or HSS
has exceeded its quota or rate of submitting enhanced coverage requests defined
by an SLA).
The MME/SGSN updates Enhanced Coverage Restricted parameters in
the MME/SGSN context.
The MME/SGSN transfers the Enhanced Coverage Restricted parameters
stored as part of its context information during the MME/SGSN change.
Note:
UE is informed of the updated Enhanced Coverage Restricted
parameters value at the next TAU/RAU or, based on the local policy, the network
can detach the UE indicating re-attach is required.
- If the Enhanced Coverage
restriction is updated successfully, the MME/SGSN sends an Insert Subscriber
Data Answer (Cause) message to HSS. MME/SGSN may include the Enhanced Coverage
Restricted parameter in the Insert Subscriber Data Answer message.
- HSS sends an Enhanced
Coverage Response (Cause) message to SCEF. HSS includes result =
success/failure and in case of success may include Enhanced Coverage
Restriction Data.
- SCEF sends an Enhanced
Coverage Response (Cause, Enhanced Coverage Restriction Data) message to the
SCS/AS. Cause indicates success or failure. If, in step 1, the Enhanced
Coverage Request message is sent to query the status of Enhanced Coverage
Restricted, then the Enhanced Coverage Restriction Data is included (in case of
success) in the Enhanced Coverage Response message.