Contention-based transmission with contention-free feedback for reducing latency in lte advanced networks and enhanced pucch

User equipment (UE) comprising physical-layer circuitry configured to:

• transmit a contention sequence on a physical uplink control channel (PUCCH) to an enhanced-Node B (eNB);
• and
• transmit data requesting uplink resources on a physical uplink shared channel (PUSCH) to the eNB,
• wherein the data transmitted on the PUSCH indicates that the UE is requesting uplink channel resources for a subsequent uplink data transmission, and
• wherein the contention sequence is transmitted on the PUCCH in accordance with a format that is assigned by the eNB.

A method performed by an enhanced-Node B (eNB) for receiving on an enhanced physical uplink control channel (PUCCH),

• wherein the PUCCH comprises first and second slots, each slot including three demodulation reference symbols (DMRS) and four data symbols,
• wherein the method further comprises:
• receiving thirty-six preamble sequences that are spread two-dimensionally over seventy-two subcarriers that carry the DMRS reference symbols;
• and
• receiving a plurality of up to forty-five or more information bits of data over ninety-six subcarriers of the four data symbols.