A system for using multiple grant-free transmission configurations, the system comprising: a cellular wireless network comprising a plurality of base stations, configured to: assign a plurality of grant-free transmission configurations to an instance of user equipment, wherein: each grant-free transmission configuration of the plurality of grant-free transmission configurations defines a different plurality of resource units, each resource unit defining a different time window and frequency; and transmit indications of the plurality of grant-free transmission configurations to the instance of user equipment; and the instance of user equipment, configured to: receive the indications of the plurality of grant-free transmission configurations; schedule a set of data for transmission using a first grant-free transmission configuration (202, 203, 204) of the plurality of grant-free transmission configurations; schedule a replication of the set of data for transmission using a second grant-free transmission configuration (302, 303, 304) of the plurality of grant-free transmission configurations; and transmit the set of data using the first grant-free transmission configuration (202 203, 204) and the replication of the set of data using the second grant-free transmission configuration (302, 303, 304). a cellular wireless network comprising a plurality of base stations, configured to: assign a plurality of grant-free transmission configurations to an instance of user equipment, wherein: each grant-free transmission configuration of the plurality of grant-free transmission configurations defines a different plurality of resource units, each resource unit defining a different time window and frequency; and transmit indications of the plurality of grant-free transmission configurations to the instance of user equipment; and assign a plurality of grant-free transmission configurations to an instance of user equipment, wherein: each grant-free transmission configuration of the plurality of grant-free transmission configurations defines a different plurality of resource units, each resource unit defining a different time window and frequency; and transmit indications of the plurality of grant-free transmission configurations to the instance of user equipment; and the instance of user equipment, configured to: receive the indications of the plurality of grant-free transmission configurations; schedule a set of data for transmission using a first grant-free transmission configuration (202, 203, 204) of the plurality of grant-free transmission configurations; schedule a replication of the set of data for transmission using a second grant-free transmission configuration (302, 303, 304) of the plurality of grant-free transmission configurations; and transmit the set of data using the first grant-free transmission configuration (202 203, 204) and the replication of the set of data using the second grant-free transmission configuration (302, 303, 304). receive the indications of the plurality of grant-free transmission configurations; schedule a set of data for transmission using a first grant-free transmission configuration (202, 203, 204) of the plurality of grant-free transmission configurations; schedule a replication of the set of data for transmission using a second grant-free transmission configuration (302, 303, 304) of the plurality of grant-free transmission configurations; and transmit the set of data using the first grant-free transmission configuration (202 203, 204) and the replication of the set of data using the second grant-free transmission configuration (302, 303, 304).