System information scheduling in machine type communication
The present disclosure relates to an apparatus for receiving system information in a wireless communication system including a receiver that receives system information configuration information and receives system information in predetermined subframes of a radio interface, and a controller that determines the predetermined subframes according to the received system information configuration information and controls the receiver to receive the system information in the predetermined subframes, wherein the system information configuration information includes a subframe scheduling field with a plurality of bits, each bit being associated with a subframe and representing whether or not system information is to be received in that subframe. The present disclosure further relates to a corresponding apparatus for transmitting system information and to the respective receiving and transmitting methods.
1. An apparatus for transmitting system information in a wireless communication system, comprising:
circuitry which, in operation, generates system information configuration information; and
a transmitter, which is coupled to the circuitry and which, in operation,
transmits the system information configuration information to a receiving apparatus, the system information configuration information defining first subframes, and
transmits the system information to the receiving apparatus in the first subframes;
wherein,
the system information configuration information indicates whether multimedia broadcast scheduling information is used to indicate second subframes for use in multimedia broadcast communication;
when the multimedia broadcast scheduling information is used to indicate the second subframes for use in multimedia broadcast communication, the first subframes are defined exclusive of the second subframes; and
when the multimedia broadcast scheduling information is not used, the first subframes are defined according to a subframe scheduling field of the system information configuration information, wherein each one of bits in the subframe scheduling field indicates whether a corresponding one of subframes is one of the first subframes.
2. The apparatus according to claim 1 , wherein
a number of the bits in the subframe scheduling field is less than or equal to a number of the subframes in a radio frame;
none of the bits is associated with a subframe used for reception of the system information configuration information, a subframe used for a physical broadcast channel, or a subframe configured for the multimedia broadcast communication; and
the system information is transmitted only in subframes indicated by the bits in the subframe scheduling field as the first subframes.
3. The apparatus according to claim 1 , wherein
the system information configuration information is transmitted either within a master information message of a radio resource control protocol carried on a physical broadcast channel or within a system information message of the radio resource control protocol scheduled in the master information message, and
the system information configuration information further comprises an indication of frequency resources for the system information including at least one of: (i) at least one of a location and a number of physical resource blocks reserved for the system information, and (ii) whether frequency hopping is applied.
4. The apparatus according to claim 1 , wherein
the receiving apparatus is a machine type communication (MTC) terminal;
the system information is MTC system information; and
none of the bits in the subframe scheduling field is associated with a subframe carrying system information for other type of communication.
5. The apparatus according to claim 1 , wherein
the system information configuration information includes:
a first subframe scheduling field and a second subframe scheduling field, each including subfields for respective subframes; and
scheduling information indicating to which frames the second subframe scheduling field applies, and
the second subframe scheduling field is applied to the frames indicated by the scheduling information whereas the first subframe scheduling field is applied to any other frames.
6. The apparatus according to claim 5 , wherein
the second subframe scheduling field has no bits associated with any predefined subframes, and
the system information configuration information includes a first bitmap application bit for indicating whether the bits in the first subframe scheduling field are to be applicable for the frames indicated in the scheduling information.
7. The apparatus according to claim 1 , wherein
the transmitter, in operation, transmits a master information message on a physical broadcast channel, the master information message including scheduling information concerning subframe scheduling of a first system information which includes the system information configuration information, and
none of the bits in the subframe scheduling field is associated with a subframe indicated as carrying the first system information in the scheduling information.
8. The apparatus according to claim 7 , wherein the scheduling information consists of a predefined number of predefined combinations of at least two of: first system information size, subframes in which the first system information can be scheduled, application of frequency hopping, frequency hopping pattern, and frequency allocation.
9. The apparatus according to claim 1 , wherein the bits in the subframe scheduling field are 10 or 40 bits long.
10. A method performed by an apparatus, the method comprising:
generating system information configuration information;
transmitting the system information configuration information to a receiving apparatus, the system information configuration information defining first subframes; and
transmitting system information to the receiving apparatus in the first subframes;
wherein,
the system information configuration information indicates whether multimedia broadcast scheduling information is used to indicate second subframes for use in multimedia broadcast communication;
when the multimedia broadcast scheduling information is used to indicate the second subframes for use in multimedia broadcast communication, the first subframes are defined exclusive of the second subframes; and
when the multimedia broadcast scheduling information is not used, the first subframes are defined according to a subframe scheduling field of the system information configuration information, wherein each one of bits in the subframe scheduling field indicates whether a corresponding one of subframes is one of the first subframes.
11. The method according to claim 10 , wherein
a number of the bits in the subframe scheduling field is less than or equal to a number of the subframes in a radio frame;
none of the bits is associated with a subframe used for reception of the system information configuration information, a subframe used for a physical broadcast channel, or a subframe configured for the multimedia broadcast communication; and
the system information is transmitted only in subframes indicated by the bits in the subframe scheduling field as the first subframes.
12. The method according to claim 10 , wherein
the system information configuration information is transmitted either within a master information message of a radio resource control protocol carried on a physical broadcast channel or within a system information message of the radio resource control protocol scheduled in the master information message, and
the system information configuration information further comprises an indication of frequency resources for the system information including at least one of: (i) at least one of a location and a number of physical resource blocks reserved for the system information, and (ii) whether frequency hopping is applied.
13. The method according to claim 10 , wherein
the receiving apparatus is a machine type communication (MTC) terminal;
the system information is MTC system information; and
none of the bits in the subframe scheduling field is associated with a subframe carrying system information for other type of communication.
14. The method according to claim 10 , wherein
the system information configuration information includes:
a first subframe scheduling field and a second subframe scheduling field, each including subfields for respective subframes; and
scheduling information indicating to which frames the second subframe scheduling field applies, and
the second subframe scheduling field is applied to the frames indicated by the scheduling information whereas the first subframe scheduling field is applied to any other frames.
15. The method according to claim 14 , wherein
the second subframe scheduling field has no bits associated with any predefined subframes, and
the system information configuration information includes a first bitmap application bit for indicating whether the bits in the first subframe scheduling field are to be applicable for the frames indicated in the scheduling information.
16. The method according to claim 10 , wherein
the transmitter, in operation, transmits a master information message on a physical broadcast channel, the master information message including scheduling information concerning subframe scheduling of a first system information which includes the system information configuration information, and
none of the bits in the subframe scheduling field is associated with a subframe indicated as carrying the first system information in the scheduling information.
17. The method according to claim 10 , wherein the scheduling information consists of a predefined number of predefined combinations of at least two of: first system information size, subframes in which the first system information can be scheduled, application of frequency hopping, frequency hopping pattern, and frequency allocation.
18. The method according to claim 10 , wherein the bits in the subframe scheduling field are 10 or 40 bits long.