The invention relates to a method of and an apparatus for processing a random access response, the method comprising the steps of: transmitting a random access preamble; receiving a random access response within a random access response time window; checking an extension field flag of the random access response; checking if the random access response matches the random access preamble; wherein if the random access response does not match the random access preamble and if the extension field flag is set to zero, the random access response reception is considered as unsuccessful and a further random access preamble is transmitted.