Patent ID: 8619613

Claim:
A method of random access resources at a network for carrier aggregation, wherein one or more uplink and downlink component carriers can be configured by the network, the method comprising: allocating, by each of a plurality of downlink component carriers, a Physical Random Access Channel configuration for at least one corresponding uplink component carrier, wherein the Physical Random Access Channel configuration indicates a preamble format and at least one available subframe number within a radio frame; allocating, by each downlink component carrier, a Physical Random Access Channel frequency position for the at least one corresponding uplink component carrier; assigning, by each downlink component carrier, a resource access pattern for each corresponding uplink component carrier, wherein the resource access pattern defines a time pattern of the at least one available subframe number indicated by the Physical Random Access Channel configuration; and transmitting the allocated Physical Random Access Channel configuration, the allocated Physical Random Access Channel frequency position, and the assigned resource access pattern on the corresponding downlink component carrier to a user equipment, wherein a same Physical Random Access Channel configuration is allocated to be transmitted by each downlink component carrier, wherein the resource access pattern further defines at least one time sub-frame occurrence of the at least one available subframe number indicated by the Physical Random Access Channel configuration, wherein a different resource access pattern is assigned to be transmitted by each downlink component carrier, and wherein a different Physical Random Access Channel frequency position is allocated to be transmitted by each downlink component carrier to solve ambiguities resulting from a use of each of the plurality of downlink component carriers.