Random access resource configuration

A method of random access transmission at a user equipment, the method comprising:

• receiving a Physical Random Access Channel configuration on one of a plurality of downlink component carriers, wherein the Physical Random Access Channel configuration indicates a preamble format and at least one available subframe number;
• receiving a Physical Random Access Channel frequency position on each of the downlink component carriers;
• receiving a resource access pattern on the one of the plurality of downlink component carriers, 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;
• selecting an available Physical Random Access Channel resource according to the resource access pattern;
• and
• transmitting a Random Access Channel preamble on the selected Physical Random Access Channel resource,
• 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, 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.

A user equipment, comprising:

• a transceiver for:
• receiving a Physical Random Access Channel configuration on one of a plurality of downlink component carriers, wherein the Physical Random Access Channel configuration indicates a preamble format and at least one available subframe number within a radio frame;
• receiving a Physical Random Access Channel frequency position on the one of the plurality of downlink component carriers;
• and
• receiving a resource access pattern on the downlink 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
• a selector for selecting an available Physical Random Access Channel resource according to the resource access pattern,
• wherein the transceiver is operable to transmit a random Access Channel preamble on the selected Physical Random Access Channel resource,
• 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, 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.

A network entity for configuring random access resources for carrier aggregation, wherein one or more uplink and downlink component carriers can be configured by the network, the network entity comprising:

• a Physical Random Access Channel configuration allocator for allocating, by each of a plurality of downlink 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;
• a Physical Random Access Channel frequency position allocator for allocating, by each of a plurality of downlink component carriers, a Physical Random Access Channel frequency position for the corresponding uplink component carrier;
• a resource access pattern assignor for 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
• a transceiver for 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 resource access pattern r 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.