System and method for applying extended accessing barring in wireless communication system
A system and a method that employs Extended Access Barring (EAB) when a Machine Type Communication (MTC) device performs an attempt to access an evolved Node B (eNB) in a wireless communication system are provided. When User Equipment (UE) supporting MTC, an MTC device, performs an attempt to access a network, the system and method determines whether it can access the network and performs the access procedure. The system and method can control the operations of UE that performs an attempt to access a network, thereby preventing excessive access.
1. A method by a user equipment (UE) in a wireless communication system, the method comprising:
receiving configuration information corresponding to an extended access barring (EAB);
identifying whether the EAB is applied to a request for a radio resource control (RRC) connection;
transmitting a first random access preamble to a base station if the EAB is not applied to the request for the RRC connection;
receiving a random access response including a first type backoff and a second type backoff; and
transmitting a second random access preamble based on one of the first type backoff and the second type backoff.
2. The method of claim 1 , further comprising:
checking if the EAB is applied to the request for the RRC connection, whether access to a cell is barred by the EAB; and
identifying, if the access to the cell is barred by the EAB, a failure of the RRC connection.
3. The method of claim 2 , wherein the checking of whether access to the cell is barred by the EAB comprises:
if the UE belongs to a category of UEs as indicated in an EAB Category contained in an EAB parameter, and if an AC of the UE belongs to a range excluding the ACs 11 to 15, considering access to a cell as barred.
4. The method of claim 1 , further comprising:
performing, if a system information block received from a base station includes an AC barring parameter for the ACB, an access barring check.
5. The method of claim 4 , wherein the performing of the access barring check comprises:
considering, if the UE has one or more ACs with a value in a first range, which is valid for the UE, access to a cell as not barred;
generating, if the UE does not have the one or more ACs with the value in the first range, a random number uniformly distributed in the range of 0 to 1; and
considering, if the random number is lower than a value indicated by the AC barring parameter, access to the cell as not barred, and considering, if the random number is not lower than the value indicated by the AC barring parameter, access to the cell as barred.
6. A user equipment (UE) in a wireless communication system, the UE comprising:
a transceiver configured to transmit and receive signals; and
a processor configured to:
receive configuration information corresponding to an extended access barring (EAB),
identify whether the EAB is applied to a request for a radio resource control (RRC) connection,
transmit a first random access preamble to a base station if the EAB is not applied to the request for the RRC connection,
receive a random access response including a first type backoff and a second type backoff, and
transmit a second random access preamble based on one of the first type backoff and the second type backoff.
7. The UE of claim 6 , wherein the processor is further configured to:
check, if the EAB is applied to the request for the RRC connection, whether access to a cell is barred by the EAB; and
identify, if the access to a cell is barred by the EAB, a failure of the RRC connection.
8. The UE of claim 7 , wherein the processor is further configured to:
consider, if the UE belongs to a category of UEs as indicated in an EAB Category contained in an EAB parameter and if an AC of the UE belongs to a range excluding the ACs 11 to 15, access to a cell as barred.
9. The UE of claim 6 , wherein the processor is further configured to:
perform, if a system information block received from a base station includes an AC barring parameter for the ACB, an access barring check.
10. The UE of claim 9 , wherein the processor is further configured to:
consider, if the UE has one or more ACs with a value in a first range, which is valid for the UE, access to a cell as not barred,
generate, if the UE does not have the one or more ACs with the value in the first range, a random number uniformly distributed in the range of 0 to 1, and
consider, if the random number is lower than a value indicated by the AC barring parameter, access to the cell as not barred, and consider, if the random number is not lower than the value indicated by the AC barring parameter, access to the cell as barred.