Patent ID: 9398612
Filing Date: 2016-07-19
CPC Classification: H04W

Claim Text:
1. A method for managing random access channel (RACH) transmission opportunities in a cell of a network, the method comprising: transmitting a first signal to a set of user equipments (UEs), the first signal assigning a first sub-set of subframes for RACH transmission by legacy UEs in the set of UEs, the first sub-set of subframes being configured as uplink subframes under an initial frame configuration, wherein the first sub-set of subframes includes at least one subframe that is configured as a downlink subframe under one or more frame configurations in a set of candidate frame configurations; transmitting a second signal to next-generation UEs in the set of UEs, the second signal assigning a second sub-set of subframes for RACH transmission opportunities by the next-generation UEs, the second sub-set of subframes being configured as uplink subframes under the initial frame configuration; restricting selection of an updated frame configuration to a subset of candidate frame configurations that maintain the first sub-set of subframes as uplink subframes, the subset of candidate frame configurations excluding the one or more frame configurations that configure at least one subframe in the first sub-set of subframes as a downlink subframe; and communicating an index associated with the updated frame configuration to the next-generation UEs, the updated frame configuration reconfiguring at least some uplink subframes in the second sub-set of subframes as downlink subframes without reconfiguring any subframes in the first sub-set of subframes such that uplink subframes allocated for RACH transmissions by the legacy UEs remain configured for uplink transmission, wherein the index goes undetected by the first sub-set of UEs.