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. A wireless communication system comprising:
a user equipment including:
a receiver, which, in operation, receives system information configuration information; and
circuitry, which is coupled to the receiver and which, in operation, determines first subframes for receiving system information according to the received system information configuration information,
wherein,
the system information configuration information indicates whether or not multimedia broadcast scheduling information, which indicates second subframes that are used for multimedia broadcast communication, is to be used,
responsive to the system information configuration information indicating the multimedia broadcast scheduling information is to be used, the circuitry determines the first subframes by excluding the second subframes,
responsive to the system information configuration information indicating the multimedia broadcast scheduling information is not to be used, the circuitry determines the first subframes, without using the multimedia broadcast scheduling information, according to a subframe scheduling field included in the system information configuration information, each bit of a plurality of bits in the subframe scheduling field being associated with a subframe and representing whether or not system information is to be received in that subframe, and
the receiver receives the system information in the determined first subframes; and
a base station including:
a transmitter, which in operation, transmits the system information configuration information and transmits the system information in the determined first subframes.
2. The wireless communication system according to claim 1 , wherein:
a number of the bits in the subframe scheduling field is less than or equal to a number of subframes in a radio frame;
none of the bits is associated with at least one type of subframes chosen from:
subframes used for reception of system information configuration information,
subframes used for a physical broadcast channel, and
subframes configured for multimedia broadcast operation; and
the system information is transmitted only on subframes indicated by the bits in the subframe scheduling field.
3. The wireless communication system according to claim 1 , wherein
the system information configuration information is received 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) a location and/or a number of physical resource blocks reserved for the system information, or (ii) whether or not frequency hopping is applied.
4. The wireless communication system according to claim 1 , wherein
the user equipment 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 another type of communication.
5. The wireless communication system 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 some 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 wireless communication system 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 indicating whether or not the bits of the first subframe scheduling field are applicable for the frames indicated in the scheduling information.
7. The wireless communication system according to claim 1 , wherein
a master information message transmitted on a physical broadcast channel includes scheduling information concerning subframe scheduling of 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.
8. The wireless communication system 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 wireless communication system according to claim 1 , wherein the plurality of bits in the subframe scheduling field is 10 or 40 bits long.
10. A method for a wireless communication system, comprising:
receiving, by a user equipment, system information configuration information;
determining, by the user equipment, first subframes for receiving system information according to the received system information configuration information, wherein the system information configuration information indicates whether or not multimedia broadcast scheduling information, which indicates second subframes that are used for multimedia broadcast communication, is to be used;
responsive to the system information configuration information indicating the multimedia broadcast scheduling information is to be used, determining, by the user equipment, the first subframes by excluding the second subframes;
responsive to the system information configuration information indicating the multimedia broadcast scheduling information is not to be used, determining, by the user equipment, the first subframes, without using the multimedia broadcast scheduling information, according to a subframe scheduling field included in the system information configuration information, each bit of a plurality of bits in the subframe scheduling field being associated with a subframe and representing whether or not system information is to be received in that subframe;
receiving, by the user equipment, the system information in the determined first subframes;
transmitting, by a base station, the system information configuration information; and
transmitting, by the base station, the system information in the determined first subframes.
11. The method according to claim 10 , wherein the plurality of bits in the subframe scheduling field is 10 or 40 bits long.